Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / host / xhci.c
diff --git a/kernel/drivers/usb/host/xhci.c b/kernel/drivers/usb/host/xhci.c
new file mode 100644 (file)
index 0000000..36bf089
--- /dev/null
@@ -0,0 +1,5033 @@
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/pci.h>
+#include <linux/irq.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/dmi.h>
+#include <linux/dma-mapping.h>
+
+#include "xhci.h"
+#include "xhci-trace.h"
+
+#define DRIVER_AUTHOR "Sarah Sharp"
+#define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"
+
+#define        PORT_WAKE_BITS  (PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E)
+
+/* Some 0.95 hardware can't handle the chain bit on a Link TRB being cleared */
+static int link_quirk;
+module_param(link_quirk, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(link_quirk, "Don't clear the chain bit on a link TRB");
+
+static unsigned int quirks;
+module_param(quirks, uint, S_IRUGO);
+MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default");
+
+/* TODO: copied from ehci-hcd.c - can this be refactored? */
+/*
+ * xhci_handshake - spin reading hc until handshake completes or fails
+ * @ptr: address of hc register to be read
+ * @mask: bits to look at in result of read
+ * @done: value of those bits when handshake succeeds
+ * @usec: timeout in microseconds
+ *
+ * Returns negative errno, or zero on success
+ *
+ * Success happens when the "mask" bits have the specified value (hardware
+ * handshake done).  There are two failure modes:  "usec" have passed (major
+ * hardware flakeout), or the register reads as all-ones (hardware removed).
+ */
+int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec)
+{
+       u32     result;
+
+       do {
+               result = readl(ptr);
+               if (result == ~(u32)0)          /* card removed */
+                       return -ENODEV;
+               result &= mask;
+               if (result == done)
+                       return 0;
+               udelay(1);
+               usec--;
+       } while (usec > 0);
+       return -ETIMEDOUT;
+}
+
+/*
+ * Disable interrupts and begin the xHCI halting process.
+ */
+void xhci_quiesce(struct xhci_hcd *xhci)
+{
+       u32 halted;
+       u32 cmd;
+       u32 mask;
+
+       mask = ~(XHCI_IRQS);
+       halted = readl(&xhci->op_regs->status) & STS_HALT;
+       if (!halted)
+               mask &= ~CMD_RUN;
+
+       cmd = readl(&xhci->op_regs->command);
+       cmd &= mask;
+       writel(cmd, &xhci->op_regs->command);
+}
+
+/*
+ * Force HC into halt state.
+ *
+ * Disable any IRQs and clear the run/stop bit.
+ * HC will complete any current and actively pipelined transactions, and
+ * should halt within 16 ms of the run/stop bit being cleared.
+ * Read HC Halted bit in the status register to see when the HC is finished.
+ */
+int xhci_halt(struct xhci_hcd *xhci)
+{
+       int ret;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Halt the HC");
+       xhci_quiesce(xhci);
+
+       ret = xhci_handshake(&xhci->op_regs->status,
+                       STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
+       if (!ret) {
+               xhci->xhc_state |= XHCI_STATE_HALTED;
+               xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
+       } else
+               xhci_warn(xhci, "Host not halted after %u microseconds.\n",
+                               XHCI_MAX_HALT_USEC);
+       return ret;
+}
+
+/*
+ * Set the run bit and wait for the host to be running.
+ */
+static int xhci_start(struct xhci_hcd *xhci)
+{
+       u32 temp;
+       int ret;
+
+       temp = readl(&xhci->op_regs->command);
+       temp |= (CMD_RUN);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Turn on HC, cmd = 0x%x.",
+                       temp);
+       writel(temp, &xhci->op_regs->command);
+
+       /*
+        * Wait for the HCHalted Status bit to be 0 to indicate the host is
+        * running.
+        */
+       ret = xhci_handshake(&xhci->op_regs->status,
+                       STS_HALT, 0, XHCI_MAX_HALT_USEC);
+       if (ret == -ETIMEDOUT)
+               xhci_err(xhci, "Host took too long to start, "
+                               "waited %u microseconds.\n",
+                               XHCI_MAX_HALT_USEC);
+       if (!ret)
+               xhci->xhc_state &= ~XHCI_STATE_HALTED;
+       return ret;
+}
+
+/*
+ * Reset a halted HC.
+ *
+ * This resets pipelines, timers, counters, state machines, etc.
+ * Transactions will be terminated immediately, and operational registers
+ * will be set to their defaults.
+ */
+int xhci_reset(struct xhci_hcd *xhci)
+{
+       u32 command;
+       u32 state;
+       int ret, i;
+
+       state = readl(&xhci->op_regs->status);
+       if ((state & STS_HALT) == 0) {
+               xhci_warn(xhci, "Host controller not halted, aborting reset.\n");
+               return 0;
+       }
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Reset the HC");
+       command = readl(&xhci->op_regs->command);
+       command |= CMD_RESET;
+       writel(command, &xhci->op_regs->command);
+
+       ret = xhci_handshake(&xhci->op_regs->command,
+                       CMD_RESET, 0, 10 * 1000 * 1000);
+       if (ret)
+               return ret;
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                        "Wait for controller to be ready for doorbell rings");
+       /*
+        * xHCI cannot write to any doorbells or operational registers other
+        * than status until the "Controller Not Ready" flag is cleared.
+        */
+       ret = xhci_handshake(&xhci->op_regs->status,
+                       STS_CNR, 0, 10 * 1000 * 1000);
+
+       for (i = 0; i < 2; ++i) {
+               xhci->bus_state[i].port_c_suspend = 0;
+               xhci->bus_state[i].suspended_ports = 0;
+               xhci->bus_state[i].resuming_ports = 0;
+       }
+
+       return ret;
+}
+
+#ifdef CONFIG_PCI
+static int xhci_free_msi(struct xhci_hcd *xhci)
+{
+       int i;
+
+       if (!xhci->msix_entries)
+               return -EINVAL;
+
+       for (i = 0; i < xhci->msix_count; i++)
+               if (xhci->msix_entries[i].vector)
+                       free_irq(xhci->msix_entries[i].vector,
+                                       xhci_to_hcd(xhci));
+       return 0;
+}
+
+/*
+ * Set up MSI
+ */
+static int xhci_setup_msi(struct xhci_hcd *xhci)
+{
+       int ret;
+       struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+       ret = pci_enable_msi(pdev);
+       if (ret) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                               "failed to allocate MSI entry");
+               return ret;
+       }
+
+       ret = request_irq(pdev->irq, xhci_msi_irq,
+                               0, "xhci_hcd", xhci_to_hcd(xhci));
+       if (ret) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                               "disable MSI interrupt");
+               pci_disable_msi(pdev);
+       }
+
+       return ret;
+}
+
+/*
+ * Free IRQs
+ * free all IRQs request
+ */
+static void xhci_free_irq(struct xhci_hcd *xhci)
+{
+       struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+       int ret;
+
+       /* return if using legacy interrupt */
+       if (xhci_to_hcd(xhci)->irq > 0)
+               return;
+
+       ret = xhci_free_msi(xhci);
+       if (!ret)
+               return;
+       if (pdev->irq > 0)
+               free_irq(pdev->irq, xhci_to_hcd(xhci));
+
+       return;
+}
+
+/*
+ * Set up MSI-X
+ */
+static int xhci_setup_msix(struct xhci_hcd *xhci)
+{
+       int i, ret = 0;
+       struct usb_hcd *hcd = xhci_to_hcd(xhci);
+       struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+
+       /*
+        * calculate number of msi-x vectors supported.
+        * - HCS_MAX_INTRS: the max number of interrupts the host can handle,
+        *   with max number of interrupters based on the xhci HCSPARAMS1.
+        * - num_online_cpus: maximum msi-x vectors per CPUs core.
+        *   Add additional 1 vector to ensure always available interrupt.
+        */
+       xhci->msix_count = min(num_online_cpus() + 1,
+                               HCS_MAX_INTRS(xhci->hcs_params1));
+
+       xhci->msix_entries =
+               kmalloc((sizeof(struct msix_entry))*xhci->msix_count,
+                               GFP_KERNEL);
+       if (!xhci->msix_entries) {
+               xhci_err(xhci, "Failed to allocate MSI-X entries\n");
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < xhci->msix_count; i++) {
+               xhci->msix_entries[i].entry = i;
+               xhci->msix_entries[i].vector = 0;
+       }
+
+       ret = pci_enable_msix_exact(pdev, xhci->msix_entries, xhci->msix_count);
+       if (ret) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                               "Failed to enable MSI-X");
+               goto free_entries;
+       }
+
+       for (i = 0; i < xhci->msix_count; i++) {
+               ret = request_irq(xhci->msix_entries[i].vector,
+                               xhci_msi_irq,
+                               0, "xhci_hcd", xhci_to_hcd(xhci));
+               if (ret)
+                       goto disable_msix;
+       }
+
+       hcd->msix_enabled = 1;
+       return ret;
+
+disable_msix:
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable MSI-X interrupt");
+       xhci_free_irq(xhci);
+       pci_disable_msix(pdev);
+free_entries:
+       kfree(xhci->msix_entries);
+       xhci->msix_entries = NULL;
+       return ret;
+}
+
+/* Free any IRQs and disable MSI-X */
+static void xhci_cleanup_msix(struct xhci_hcd *xhci)
+{
+       struct usb_hcd *hcd = xhci_to_hcd(xhci);
+       struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+
+       if (xhci->quirks & XHCI_PLAT)
+               return;
+
+       xhci_free_irq(xhci);
+
+       if (xhci->msix_entries) {
+               pci_disable_msix(pdev);
+               kfree(xhci->msix_entries);
+               xhci->msix_entries = NULL;
+       } else {
+               pci_disable_msi(pdev);
+       }
+
+       hcd->msix_enabled = 0;
+       return;
+}
+
+static void __maybe_unused xhci_msix_sync_irqs(struct xhci_hcd *xhci)
+{
+       int i;
+
+       if (xhci->msix_entries) {
+               for (i = 0; i < xhci->msix_count; i++)
+                       synchronize_irq(xhci->msix_entries[i].vector);
+       }
+}
+
+static int xhci_try_enable_msi(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct pci_dev  *pdev;
+       int ret;
+
+       /* The xhci platform device has set up IRQs through usb_add_hcd. */
+       if (xhci->quirks & XHCI_PLAT)
+               return 0;
+
+       pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+       /*
+        * Some Fresco Logic host controllers advertise MSI, but fail to
+        * generate interrupts.  Don't even try to enable MSI.
+        */
+       if (xhci->quirks & XHCI_BROKEN_MSI)
+               goto legacy_irq;
+
+       /* unregister the legacy interrupt */
+       if (hcd->irq)
+               free_irq(hcd->irq, hcd);
+       hcd->irq = 0;
+
+       ret = xhci_setup_msix(xhci);
+       if (ret)
+               /* fall back to msi*/
+               ret = xhci_setup_msi(xhci);
+
+       if (!ret)
+               /* hcd->irq is 0, we have MSI */
+               return 0;
+
+       if (!pdev->irq) {
+               xhci_err(xhci, "No msi-x/msi found and no IRQ in BIOS\n");
+               return -EINVAL;
+       }
+
+ legacy_irq:
+       if (!strlen(hcd->irq_descr))
+               snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
+                        hcd->driver->description, hcd->self.busnum);
+
+       /* fall back to legacy interrupt*/
+       ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
+                       hcd->irq_descr, hcd);
+       if (ret) {
+               xhci_err(xhci, "request interrupt %d failed\n",
+                               pdev->irq);
+               return ret;
+       }
+       hcd->irq = pdev->irq;
+       return 0;
+}
+
+#else
+
+static inline int xhci_try_enable_msi(struct usb_hcd *hcd)
+{
+       return 0;
+}
+
+static inline void xhci_cleanup_msix(struct xhci_hcd *xhci)
+{
+}
+
+static inline void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
+{
+}
+
+#endif
+
+static void compliance_mode_recovery(unsigned long arg)
+{
+       struct xhci_hcd *xhci;
+       struct usb_hcd *hcd;
+       u32 temp;
+       int i;
+
+       xhci = (struct xhci_hcd *)arg;
+
+       for (i = 0; i < xhci->num_usb3_ports; i++) {
+               temp = readl(xhci->usb3_ports[i]);
+               if ((temp & PORT_PLS_MASK) == USB_SS_PORT_LS_COMP_MOD) {
+                       /*
+                        * Compliance Mode Detected. Letting USB Core
+                        * handle the Warm Reset
+                        */
+                       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                                       "Compliance mode detected->port %d",
+                                       i + 1);
+                       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                                       "Attempting compliance mode recovery");
+                       hcd = xhci->shared_hcd;
+
+                       if (hcd->state == HC_STATE_SUSPENDED)
+                               usb_hcd_resume_root_hub(hcd);
+
+                       usb_hcd_poll_rh_status(hcd);
+               }
+       }
+
+       if (xhci->port_status_u0 != ((1 << xhci->num_usb3_ports)-1))
+               mod_timer(&xhci->comp_mode_recovery_timer,
+                       jiffies + msecs_to_jiffies(COMP_MODE_RCVRY_MSECS));
+}
+
+/*
+ * Quirk to work around issue generated by the SN65LVPE502CP USB3.0 re-driver
+ * that causes ports behind that hardware to enter compliance mode sometimes.
+ * The quirk creates a timer that polls every 2 seconds the link state of
+ * each host controller's port and recovers it by issuing a Warm reset
+ * if Compliance mode is detected, otherwise the port will become "dead" (no
+ * device connections or disconnections will be detected anymore). Becasue no
+ * status event is generated when entering compliance mode (per xhci spec),
+ * this quirk is needed on systems that have the failing hardware installed.
+ */
+static void compliance_mode_recovery_timer_init(struct xhci_hcd *xhci)
+{
+       xhci->port_status_u0 = 0;
+       setup_timer(&xhci->comp_mode_recovery_timer,
+                   compliance_mode_recovery, (unsigned long)xhci);
+       xhci->comp_mode_recovery_timer.expires = jiffies +
+                       msecs_to_jiffies(COMP_MODE_RCVRY_MSECS);
+
+       set_timer_slack(&xhci->comp_mode_recovery_timer,
+                       msecs_to_jiffies(COMP_MODE_RCVRY_MSECS));
+       add_timer(&xhci->comp_mode_recovery_timer);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                       "Compliance mode recovery timer initialized");
+}
+
+/*
+ * This function identifies the systems that have installed the SN65LVPE502CP
+ * USB3.0 re-driver and that need the Compliance Mode Quirk.
+ * Systems:
+ * Vendor: Hewlett-Packard -> System Models: Z420, Z620 and Z820
+ */
+static bool xhci_compliance_mode_recovery_timer_quirk_check(void)
+{
+       const char *dmi_product_name, *dmi_sys_vendor;
+
+       dmi_product_name = dmi_get_system_info(DMI_PRODUCT_NAME);
+       dmi_sys_vendor = dmi_get_system_info(DMI_SYS_VENDOR);
+       if (!dmi_product_name || !dmi_sys_vendor)
+               return false;
+
+       if (!(strstr(dmi_sys_vendor, "Hewlett-Packard")))
+               return false;
+
+       if (strstr(dmi_product_name, "Z420") ||
+                       strstr(dmi_product_name, "Z620") ||
+                       strstr(dmi_product_name, "Z820") ||
+                       strstr(dmi_product_name, "Z1 Workstation"))
+               return true;
+
+       return false;
+}
+
+static int xhci_all_ports_seen_u0(struct xhci_hcd *xhci)
+{
+       return (xhci->port_status_u0 == ((1 << xhci->num_usb3_ports)-1));
+}
+
+
+/*
+ * Initialize memory for HCD and xHC (one-time init).
+ *
+ * Program the PAGESIZE register, initialize the device context array, create
+ * device contexts (?), set up a command ring segment (or two?), create event
+ * ring (one for now).
+ */
+int xhci_init(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       int retval = 0;
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "xhci_init");
+       spin_lock_init(&xhci->lock);
+       if (xhci->hci_version == 0x95 && link_quirk) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "QUIRK: Not clearing Link TRB chain bits.");
+               xhci->quirks |= XHCI_LINK_TRB_QUIRK;
+       } else {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                               "xHCI doesn't need link TRB QUIRK");
+       }
+       retval = xhci_mem_init(xhci, GFP_KERNEL);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Finished xhci_init");
+
+       /* Initializing Compliance Mode Recovery Data If Needed */
+       if (xhci_compliance_mode_recovery_timer_quirk_check()) {
+               xhci->quirks |= XHCI_COMP_MODE_QUIRK;
+               compliance_mode_recovery_timer_init(xhci);
+       }
+
+       return retval;
+}
+
+/*-------------------------------------------------------------------------*/
+
+
+static int xhci_run_finished(struct xhci_hcd *xhci)
+{
+       if (xhci_start(xhci)) {
+               xhci_halt(xhci);
+               return -ENODEV;
+       }
+       xhci->shared_hcd->state = HC_STATE_RUNNING;
+       xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
+
+       if (xhci->quirks & XHCI_NEC_HOST)
+               xhci_ring_cmd_db(xhci);
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "Finished xhci_run for USB3 roothub");
+       return 0;
+}
+
+/*
+ * Start the HC after it was halted.
+ *
+ * This function is called by the USB core when the HC driver is added.
+ * Its opposite is xhci_stop().
+ *
+ * xhci_init() must be called once before this function can be called.
+ * Reset the HC, enable device slot contexts, program DCBAAP, and
+ * set command ring pointer and event ring pointer.
+ *
+ * Setup MSI-X vectors and enable interrupts.
+ */
+int xhci_run(struct usb_hcd *hcd)
+{
+       u32 temp;
+       u64 temp_64;
+       int ret;
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+       /* Start the xHCI host controller running only after the USB 2.0 roothub
+        * is setup.
+        */
+
+       hcd->uses_new_polling = 1;
+       if (!usb_hcd_is_primary_hcd(hcd))
+               return xhci_run_finished(xhci);
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "xhci_run");
+
+       ret = xhci_try_enable_msi(hcd);
+       if (ret)
+               return ret;
+
+       xhci_dbg(xhci, "Command ring memory map follows:\n");
+       xhci_debug_ring(xhci, xhci->cmd_ring);
+       xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
+       xhci_dbg_cmd_ptrs(xhci);
+
+       xhci_dbg(xhci, "ERST memory map follows:\n");
+       xhci_dbg_erst(xhci, &xhci->erst);
+       xhci_dbg(xhci, "Event ring:\n");
+       xhci_debug_ring(xhci, xhci->event_ring);
+       xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
+       temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+       temp_64 &= ~ERST_PTR_MASK;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "ERST deq = 64'h%0lx", (long unsigned int) temp_64);
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "// Set the interrupt modulation register");
+       temp = readl(&xhci->ir_set->irq_control);
+       temp &= ~ER_IRQ_INTERVAL_MASK;
+       temp |= (u32) 160;
+       writel(temp, &xhci->ir_set->irq_control);
+
+       /* Set the HCD state before we enable the irqs */
+       temp = readl(&xhci->op_regs->command);
+       temp |= (CMD_EIE);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "// Enable interrupts, cmd = 0x%x.", temp);
+       writel(temp, &xhci->op_regs->command);
+
+       temp = readl(&xhci->ir_set->irq_pending);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "// Enabling event ring interrupter %p by writing 0x%x to irq_pending",
+                       xhci->ir_set, (unsigned int) ER_IRQ_ENABLE(temp));
+       writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending);
+       xhci_print_ir_set(xhci, 0);
+
+       if (xhci->quirks & XHCI_NEC_HOST) {
+               struct xhci_command *command;
+               command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
+               if (!command)
+                       return -ENOMEM;
+               xhci_queue_vendor_command(xhci, command, 0, 0, 0,
+                               TRB_TYPE(TRB_NEC_GET_FW));
+       }
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "Finished xhci_run for USB2 roothub");
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_run);
+
+static void xhci_only_stop_hcd(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+       spin_lock_irq(&xhci->lock);
+       xhci_halt(xhci);
+
+       /* The shared_hcd is going to be deallocated shortly (the USB core only
+        * calls this function when allocation fails in usb_add_hcd(), or
+        * usb_remove_hcd() is called).  So we need to unset xHCI's pointer.
+        */
+       xhci->shared_hcd = NULL;
+       spin_unlock_irq(&xhci->lock);
+}
+
+/*
+ * Stop xHCI driver.
+ *
+ * This function is called by the USB core when the HC driver is removed.
+ * Its opposite is xhci_run().
+ *
+ * Disable device contexts, disable IRQs, and quiesce the HC.
+ * Reset the HC, finish any completed transactions, and cleanup memory.
+ */
+void xhci_stop(struct usb_hcd *hcd)
+{
+       u32 temp;
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+       if (!usb_hcd_is_primary_hcd(hcd)) {
+               xhci_only_stop_hcd(xhci->shared_hcd);
+               return;
+       }
+
+       spin_lock_irq(&xhci->lock);
+       /* Make sure the xHC is halted for a USB3 roothub
+        * (xhci_stop() could be called as part of failed init).
+        */
+       xhci_halt(xhci);
+       xhci_reset(xhci);
+       spin_unlock_irq(&xhci->lock);
+
+       xhci_cleanup_msix(xhci);
+
+       /* Deleting Compliance Mode Recovery Timer */
+       if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
+                       (!(xhci_all_ports_seen_u0(xhci)))) {
+               del_timer_sync(&xhci->comp_mode_recovery_timer);
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "%s: compliance mode recovery timer deleted",
+                               __func__);
+       }
+
+       if (xhci->quirks & XHCI_AMD_PLL_FIX)
+               usb_amd_dev_put();
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "// Disabling event ring interrupts");
+       temp = readl(&xhci->op_regs->status);
+       writel(temp & ~STS_EINT, &xhci->op_regs->status);
+       temp = readl(&xhci->ir_set->irq_pending);
+       writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending);
+       xhci_print_ir_set(xhci, 0);
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init, "cleaning up memory");
+       xhci_mem_cleanup(xhci);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "xhci_stop completed - status = %x",
+                       readl(&xhci->op_regs->status));
+}
+
+/*
+ * Shutdown HC (not bus-specific)
+ *
+ * This is called when the machine is rebooting or halting.  We assume that the
+ * machine will be powered off, and the HC's internal state will be reset.
+ * Don't bother to free memory.
+ *
+ * This will only ever be called with the main usb_hcd (the USB3 roothub).
+ */
+void xhci_shutdown(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+       if (xhci->quirks & XHCI_SPURIOUS_REBOOT)
+               usb_disable_xhci_ports(to_pci_dev(hcd->self.controller));
+
+       spin_lock_irq(&xhci->lock);
+       xhci_halt(xhci);
+       /* Workaround for spurious wakeups at shutdown with HSW */
+       if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
+               xhci_reset(xhci);
+       spin_unlock_irq(&xhci->lock);
+
+       xhci_cleanup_msix(xhci);
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "xhci_shutdown completed - status = %x",
+                       readl(&xhci->op_regs->status));
+
+       /* Yet another workaround for spurious wakeups at shutdown with HSW */
+       if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
+               pci_set_power_state(to_pci_dev(hcd->self.controller), PCI_D3hot);
+}
+
+#ifdef CONFIG_PM
+static void xhci_save_registers(struct xhci_hcd *xhci)
+{
+       xhci->s3.command = readl(&xhci->op_regs->command);
+       xhci->s3.dev_nt = readl(&xhci->op_regs->dev_notification);
+       xhci->s3.dcbaa_ptr = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
+       xhci->s3.config_reg = readl(&xhci->op_regs->config_reg);
+       xhci->s3.erst_size = readl(&xhci->ir_set->erst_size);
+       xhci->s3.erst_base = xhci_read_64(xhci, &xhci->ir_set->erst_base);
+       xhci->s3.erst_dequeue = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+       xhci->s3.irq_pending = readl(&xhci->ir_set->irq_pending);
+       xhci->s3.irq_control = readl(&xhci->ir_set->irq_control);
+}
+
+static void xhci_restore_registers(struct xhci_hcd *xhci)
+{
+       writel(xhci->s3.command, &xhci->op_regs->command);
+       writel(xhci->s3.dev_nt, &xhci->op_regs->dev_notification);
+       xhci_write_64(xhci, xhci->s3.dcbaa_ptr, &xhci->op_regs->dcbaa_ptr);
+       writel(xhci->s3.config_reg, &xhci->op_regs->config_reg);
+       writel(xhci->s3.erst_size, &xhci->ir_set->erst_size);
+       xhci_write_64(xhci, xhci->s3.erst_base, &xhci->ir_set->erst_base);
+       xhci_write_64(xhci, xhci->s3.erst_dequeue, &xhci->ir_set->erst_dequeue);
+       writel(xhci->s3.irq_pending, &xhci->ir_set->irq_pending);
+       writel(xhci->s3.irq_control, &xhci->ir_set->irq_control);
+}
+
+static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)
+{
+       u64     val_64;
+
+       /* step 2: initialize command ring buffer */
+       val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
+       val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) |
+               (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
+                                     xhci->cmd_ring->dequeue) &
+                (u64) ~CMD_RING_RSVD_BITS) |
+               xhci->cmd_ring->cycle_state;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_init,
+                       "// Setting command ring address to 0x%llx",
+                       (long unsigned long) val_64);
+       xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring);
+}
+
+/*
+ * The whole command ring must be cleared to zero when we suspend the host.
+ *
+ * The host doesn't save the command ring pointer in the suspend well, so we
+ * need to re-program it on resume.  Unfortunately, the pointer must be 64-byte
+ * aligned, because of the reserved bits in the command ring dequeue pointer
+ * register.  Therefore, we can't just set the dequeue pointer back in the
+ * middle of the ring (TRBs are 16-byte aligned).
+ */
+static void xhci_clear_command_ring(struct xhci_hcd *xhci)
+{
+       struct xhci_ring *ring;
+       struct xhci_segment *seg;
+
+       ring = xhci->cmd_ring;
+       seg = ring->deq_seg;
+       do {
+               memset(seg->trbs, 0,
+                       sizeof(union xhci_trb) * (TRBS_PER_SEGMENT - 1));
+               seg->trbs[TRBS_PER_SEGMENT - 1].link.control &=
+                       cpu_to_le32(~TRB_CYCLE);
+               seg = seg->next;
+       } while (seg != ring->deq_seg);
+
+       /* Reset the software enqueue and dequeue pointers */
+       ring->deq_seg = ring->first_seg;
+       ring->dequeue = ring->first_seg->trbs;
+       ring->enq_seg = ring->deq_seg;
+       ring->enqueue = ring->dequeue;
+
+       ring->num_trbs_free = ring->num_segs * (TRBS_PER_SEGMENT - 1) - 1;
+       /*
+        * Ring is now zeroed, so the HW should look for change of ownership
+        * when the cycle bit is set to 1.
+        */
+       ring->cycle_state = 1;
+
+       /*
+        * Reset the hardware dequeue pointer.
+        * Yes, this will need to be re-written after resume, but we're paranoid
+        * and want to make sure the hardware doesn't access bogus memory
+        * because, say, the BIOS or an SMI started the host without changing
+        * the command ring pointers.
+        */
+       xhci_set_cmd_ring_deq(xhci);
+}
+
+static void xhci_disable_port_wake_on_bits(struct xhci_hcd *xhci)
+{
+       int port_index;
+       __le32 __iomem **port_array;
+       unsigned long flags;
+       u32 t1, t2;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+
+       /* disble usb3 ports Wake bits*/
+       port_index = xhci->num_usb3_ports;
+       port_array = xhci->usb3_ports;
+       while (port_index--) {
+               t1 = readl(port_array[port_index]);
+               t1 = xhci_port_state_to_neutral(t1);
+               t2 = t1 & ~PORT_WAKE_BITS;
+               if (t1 != t2)
+                       writel(t2, port_array[port_index]);
+       }
+
+       /* disble usb2 ports Wake bits*/
+       port_index = xhci->num_usb2_ports;
+       port_array = xhci->usb2_ports;
+       while (port_index--) {
+               t1 = readl(port_array[port_index]);
+               t1 = xhci_port_state_to_neutral(t1);
+               t2 = t1 & ~PORT_WAKE_BITS;
+               if (t1 != t2)
+                       writel(t2, port_array[port_index]);
+       }
+
+       spin_unlock_irqrestore(&xhci->lock, flags);
+}
+
+/*
+ * Stop HC (not bus-specific)
+ *
+ * This is called when the machine transition into S3/S4 mode.
+ *
+ */
+int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
+{
+       int                     rc = 0;
+       unsigned int            delay = XHCI_MAX_HALT_USEC;
+       struct usb_hcd          *hcd = xhci_to_hcd(xhci);
+       u32                     command;
+
+       if (hcd->state != HC_STATE_SUSPENDED ||
+                       xhci->shared_hcd->state != HC_STATE_SUSPENDED)
+               return -EINVAL;
+
+       /* Clear root port wake on bits if wakeup not allowed. */
+       if (!do_wakeup)
+               xhci_disable_port_wake_on_bits(xhci);
+
+       /* Don't poll the roothubs on bus suspend. */
+       xhci_dbg(xhci, "%s: stopping port polling.\n", __func__);
+       clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+       del_timer_sync(&hcd->rh_timer);
+       clear_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
+       del_timer_sync(&xhci->shared_hcd->rh_timer);
+
+       spin_lock_irq(&xhci->lock);
+       clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+       clear_bit(HCD_FLAG_HW_ACCESSIBLE, &xhci->shared_hcd->flags);
+       /* step 1: stop endpoint */
+       /* skipped assuming that port suspend has done */
+
+       /* step 2: clear Run/Stop bit */
+       command = readl(&xhci->op_regs->command);
+       command &= ~CMD_RUN;
+       writel(command, &xhci->op_regs->command);
+
+       /* Some chips from Fresco Logic need an extraordinary delay */
+       delay *= (xhci->quirks & XHCI_SLOW_SUSPEND) ? 10 : 1;
+
+       if (xhci_handshake(&xhci->op_regs->status,
+                     STS_HALT, STS_HALT, delay)) {
+               xhci_warn(xhci, "WARN: xHC CMD_RUN timeout\n");
+               spin_unlock_irq(&xhci->lock);
+               return -ETIMEDOUT;
+       }
+       xhci_clear_command_ring(xhci);
+
+       /* step 3: save registers */
+       xhci_save_registers(xhci);
+
+       /* step 4: set CSS flag */
+       command = readl(&xhci->op_regs->command);
+       command |= CMD_CSS;
+       writel(command, &xhci->op_regs->command);
+       if (xhci_handshake(&xhci->op_regs->status,
+                               STS_SAVE, 0, 10 * 1000)) {
+               xhci_warn(xhci, "WARN: xHC save state timeout\n");
+               spin_unlock_irq(&xhci->lock);
+               return -ETIMEDOUT;
+       }
+       spin_unlock_irq(&xhci->lock);
+
+       /*
+        * Deleting Compliance Mode Recovery Timer because the xHCI Host
+        * is about to be suspended.
+        */
+       if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
+                       (!(xhci_all_ports_seen_u0(xhci)))) {
+               del_timer_sync(&xhci->comp_mode_recovery_timer);
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "%s: compliance mode recovery timer deleted",
+                               __func__);
+       }
+
+       /* step 5: remove core well power */
+       /* synchronize irq when using MSI-X */
+       xhci_msix_sync_irqs(xhci);
+
+       return rc;
+}
+EXPORT_SYMBOL_GPL(xhci_suspend);
+
+/*
+ * start xHC (not bus-specific)
+ *
+ * This is called when the machine transition from S3/S4 mode.
+ *
+ */
+int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
+{
+       u32                     command, temp = 0, status;
+       struct usb_hcd          *hcd = xhci_to_hcd(xhci);
+       struct usb_hcd          *secondary_hcd;
+       int                     retval = 0;
+       bool                    comp_timer_running = false;
+
+       /* Wait a bit if either of the roothubs need to settle from the
+        * transition into bus suspend.
+        */
+       if (time_before(jiffies, xhci->bus_state[0].next_statechange) ||
+                       time_before(jiffies,
+                               xhci->bus_state[1].next_statechange))
+               msleep(100);
+
+       set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+       set_bit(HCD_FLAG_HW_ACCESSIBLE, &xhci->shared_hcd->flags);
+
+       spin_lock_irq(&xhci->lock);
+       if (xhci->quirks & XHCI_RESET_ON_RESUME)
+               hibernated = true;
+
+       if (!hibernated) {
+               /* step 1: restore register */
+               xhci_restore_registers(xhci);
+               /* step 2: initialize command ring buffer */
+               xhci_set_cmd_ring_deq(xhci);
+               /* step 3: restore state and start state*/
+               /* step 3: set CRS flag */
+               command = readl(&xhci->op_regs->command);
+               command |= CMD_CRS;
+               writel(command, &xhci->op_regs->command);
+               if (xhci_handshake(&xhci->op_regs->status,
+                             STS_RESTORE, 0, 10 * 1000)) {
+                       xhci_warn(xhci, "WARN: xHC restore state timeout\n");
+                       spin_unlock_irq(&xhci->lock);
+                       return -ETIMEDOUT;
+               }
+               temp = readl(&xhci->op_regs->status);
+       }
+
+       /* If restore operation fails, re-initialize the HC during resume */
+       if ((temp & STS_SRE) || hibernated) {
+
+               if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
+                               !(xhci_all_ports_seen_u0(xhci))) {
+                       del_timer_sync(&xhci->comp_mode_recovery_timer);
+                       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Compliance Mode Recovery Timer deleted!");
+               }
+
+               /* Let the USB core know _both_ roothubs lost power. */
+               usb_root_hub_lost_power(xhci->main_hcd->self.root_hub);
+               usb_root_hub_lost_power(xhci->shared_hcd->self.root_hub);
+
+               xhci_dbg(xhci, "Stop HCD\n");
+               xhci_halt(xhci);
+               xhci_reset(xhci);
+               spin_unlock_irq(&xhci->lock);
+               xhci_cleanup_msix(xhci);
+
+               xhci_dbg(xhci, "// Disabling event ring interrupts\n");
+               temp = readl(&xhci->op_regs->status);
+               writel(temp & ~STS_EINT, &xhci->op_regs->status);
+               temp = readl(&xhci->ir_set->irq_pending);
+               writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending);
+               xhci_print_ir_set(xhci, 0);
+
+               xhci_dbg(xhci, "cleaning up memory\n");
+               xhci_mem_cleanup(xhci);
+               xhci_dbg(xhci, "xhci_stop completed - status = %x\n",
+                           readl(&xhci->op_regs->status));
+
+               /* USB core calls the PCI reinit and start functions twice:
+                * first with the primary HCD, and then with the secondary HCD.
+                * If we don't do the same, the host will never be started.
+                */
+               if (!usb_hcd_is_primary_hcd(hcd))
+                       secondary_hcd = hcd;
+               else
+                       secondary_hcd = xhci->shared_hcd;
+
+               xhci_dbg(xhci, "Initialize the xhci_hcd\n");
+               retval = xhci_init(hcd->primary_hcd);
+               if (retval)
+                       return retval;
+               comp_timer_running = true;
+
+               xhci_dbg(xhci, "Start the primary HCD\n");
+               retval = xhci_run(hcd->primary_hcd);
+               if (!retval) {
+                       xhci_dbg(xhci, "Start the secondary HCD\n");
+                       retval = xhci_run(secondary_hcd);
+               }
+               hcd->state = HC_STATE_SUSPENDED;
+               xhci->shared_hcd->state = HC_STATE_SUSPENDED;
+               goto done;
+       }
+
+       /* step 4: set Run/Stop bit */
+       command = readl(&xhci->op_regs->command);
+       command |= CMD_RUN;
+       writel(command, &xhci->op_regs->command);
+       xhci_handshake(&xhci->op_regs->status, STS_HALT,
+                 0, 250 * 1000);
+
+       /* step 5: walk topology and initialize portsc,
+        * portpmsc and portli
+        */
+       /* this is done in bus_resume */
+
+       /* step 6: restart each of the previously
+        * Running endpoints by ringing their doorbells
+        */
+
+       spin_unlock_irq(&xhci->lock);
+
+ done:
+       if (retval == 0) {
+               /* Resume root hubs only when have pending events. */
+               status = readl(&xhci->op_regs->status);
+               if (status & STS_EINT) {
+                       usb_hcd_resume_root_hub(hcd);
+                       usb_hcd_resume_root_hub(xhci->shared_hcd);
+               }
+       }
+
+       /*
+        * If system is subject to the Quirk, Compliance Mode Timer needs to
+        * be re-initialized Always after a system resume. Ports are subject
+        * to suffer the Compliance Mode issue again. It doesn't matter if
+        * ports have entered previously to U0 before system's suspension.
+        */
+       if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) && !comp_timer_running)
+               compliance_mode_recovery_timer_init(xhci);
+
+       /* Re-enable port polling. */
+       xhci_dbg(xhci, "%s: starting port polling.\n", __func__);
+       set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+       usb_hcd_poll_rh_status(hcd);
+       set_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
+       usb_hcd_poll_rh_status(xhci->shared_hcd);
+
+       return retval;
+}
+EXPORT_SYMBOL_GPL(xhci_resume);
+#endif /* CONFIG_PM */
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * xhci_get_endpoint_index - Used for passing endpoint bitmasks between the core and
+ * HCDs.  Find the index for an endpoint given its descriptor.  Use the return
+ * value to right shift 1 for the bitmask.
+ *
+ * Index  = (epnum * 2) + direction - 1,
+ * where direction = 0 for OUT, 1 for IN.
+ * For control endpoints, the IN index is used (OUT index is unused), so
+ * index = (epnum * 2) + direction - 1 = (epnum * 2) + 1 - 1 = (epnum * 2)
+ */
+unsigned int xhci_get_endpoint_index(struct usb_endpoint_descriptor *desc)
+{
+       unsigned int index;
+       if (usb_endpoint_xfer_control(desc))
+               index = (unsigned int) (usb_endpoint_num(desc)*2);
+       else
+               index = (unsigned int) (usb_endpoint_num(desc)*2) +
+                       (usb_endpoint_dir_in(desc) ? 1 : 0) - 1;
+       return index;
+}
+
+/* The reverse operation to xhci_get_endpoint_index. Calculate the USB endpoint
+ * address from the XHCI endpoint index.
+ */
+unsigned int xhci_get_endpoint_address(unsigned int ep_index)
+{
+       unsigned int number = DIV_ROUND_UP(ep_index, 2);
+       unsigned int direction = ep_index % 2 ? USB_DIR_OUT : USB_DIR_IN;
+       return direction | number;
+}
+
+/* Find the flag for this endpoint (for use in the control context).  Use the
+ * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
+ * bit 1, etc.
+ */
+unsigned int xhci_get_endpoint_flag(struct usb_endpoint_descriptor *desc)
+{
+       return 1 << (xhci_get_endpoint_index(desc) + 1);
+}
+
+/* Find the flag for this endpoint (for use in the control context).  Use the
+ * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
+ * bit 1, etc.
+ */
+unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index)
+{
+       return 1 << (ep_index + 1);
+}
+
+/* Compute the last valid endpoint context index.  Basically, this is the
+ * endpoint index plus one.  For slot contexts with more than valid endpoint,
+ * we find the most significant bit set in the added contexts flags.
+ * e.g. ep 1 IN (with epnum 0x81) => added_ctxs = 0b1000
+ * fls(0b1000) = 4, but the endpoint context index is 3, so subtract one.
+ */
+unsigned int xhci_last_valid_endpoint(u32 added_ctxs)
+{
+       return fls(added_ctxs) - 1;
+}
+
+/* Returns 1 if the arguments are OK;
+ * returns 0 this is a root hub; returns -EINVAL for NULL pointers.
+ */
+static int xhci_check_args(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep, int check_ep, bool check_virt_dev,
+               const char *func) {
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *virt_dev;
+
+       if (!hcd || (check_ep && !ep) || !udev) {
+               pr_debug("xHCI %s called with invalid args\n", func);
+               return -EINVAL;
+       }
+       if (!udev->parent) {
+               pr_debug("xHCI %s called for root hub\n", func);
+               return 0;
+       }
+
+       xhci = hcd_to_xhci(hcd);
+       if (check_virt_dev) {
+               if (!udev->slot_id || !xhci->devs[udev->slot_id]) {
+                       xhci_dbg(xhci, "xHCI %s called with unaddressed device\n",
+                                       func);
+                       return -EINVAL;
+               }
+
+               virt_dev = xhci->devs[udev->slot_id];
+               if (virt_dev->udev != udev) {
+                       xhci_dbg(xhci, "xHCI %s called with udev and "
+                                         "virt_dev does not match\n", func);
+                       return -EINVAL;
+               }
+       }
+
+       if (xhci->xhc_state & XHCI_STATE_HALTED)
+               return -ENODEV;
+
+       return 1;
+}
+
+static int xhci_configure_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev, struct xhci_command *command,
+               bool ctx_change, bool must_succeed);
+
+/*
+ * Full speed devices may have a max packet size greater than 8 bytes, but the
+ * USB core doesn't know that until it reads the first 8 bytes of the
+ * descriptor.  If the usb_device's max packet size changes after that point,
+ * we need to issue an evaluate context command and wait on it.
+ */
+static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id,
+               unsigned int ep_index, struct urb *urb)
+{
+       struct xhci_container_ctx *out_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       struct xhci_command *command;
+       int max_packet_size;
+       int hw_max_packet_size;
+       int ret = 0;
+
+       out_ctx = xhci->devs[slot_id]->out_ctx;
+       ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
+       hw_max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
+       max_packet_size = usb_endpoint_maxp(&urb->dev->ep0.desc);
+       if (hw_max_packet_size != max_packet_size) {
+               xhci_dbg_trace(xhci,  trace_xhci_dbg_context_change,
+                               "Max Packet Size for ep 0 changed.");
+               xhci_dbg_trace(xhci,  trace_xhci_dbg_context_change,
+                               "Max packet size in usb_device = %d",
+                               max_packet_size);
+               xhci_dbg_trace(xhci,  trace_xhci_dbg_context_change,
+                               "Max packet size in xHCI HW = %d",
+                               hw_max_packet_size);
+               xhci_dbg_trace(xhci,  trace_xhci_dbg_context_change,
+                               "Issuing evaluate context command.");
+
+               /* Set up the input context flags for the command */
+               /* FIXME: This won't work if a non-default control endpoint
+                * changes max packet sizes.
+                */
+
+               command = xhci_alloc_command(xhci, false, true, GFP_KERNEL);
+               if (!command)
+                       return -ENOMEM;
+
+               command->in_ctx = xhci->devs[slot_id]->in_ctx;
+               ctrl_ctx = xhci_get_input_control_ctx(command->in_ctx);
+               if (!ctrl_ctx) {
+                       xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                                       __func__);
+                       ret = -ENOMEM;
+                       goto command_cleanup;
+               }
+               /* Set up the modified control endpoint 0 */
+               xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
+                               xhci->devs[slot_id]->out_ctx, ep_index);
+
+               ep_ctx = xhci_get_ep_ctx(xhci, command->in_ctx, ep_index);
+               ep_ctx->ep_info2 &= cpu_to_le32(~MAX_PACKET_MASK);
+               ep_ctx->ep_info2 |= cpu_to_le32(MAX_PACKET(max_packet_size));
+
+               ctrl_ctx->add_flags = cpu_to_le32(EP0_FLAG);
+               ctrl_ctx->drop_flags = 0;
+
+               xhci_dbg(xhci, "Slot %d input context\n", slot_id);
+               xhci_dbg_ctx(xhci, command->in_ctx, ep_index);
+               xhci_dbg(xhci, "Slot %d output context\n", slot_id);
+               xhci_dbg_ctx(xhci, out_ctx, ep_index);
+
+               ret = xhci_configure_endpoint(xhci, urb->dev, command,
+                               true, false);
+
+               /* Clean up the input context for later use by bandwidth
+                * functions.
+                */
+               ctrl_ctx->add_flags = cpu_to_le32(SLOT_FLAG);
+command_cleanup:
+               kfree(command->completion);
+               kfree(command);
+       }
+       return ret;
+}
+
+/*
+ * non-error returns are a promise to giveback() the urb later
+ * we drop ownership so next owner (or urb unlink) can get it
+ */
+int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_td *buffer;
+       unsigned long flags;
+       int ret = 0;
+       unsigned int slot_id, ep_index;
+       struct urb_priv *urb_priv;
+       int size, i;
+
+       if (!urb || xhci_check_args(hcd, urb->dev, urb->ep,
+                                       true, true, __func__) <= 0)
+               return -EINVAL;
+
+       slot_id = urb->dev->slot_id;
+       ep_index = xhci_get_endpoint_index(&urb->ep->desc);
+
+       if (!HCD_HW_ACCESSIBLE(hcd)) {
+               if (!in_interrupt())
+                       xhci_dbg(xhci, "urb submitted during PCI suspend\n");
+               ret = -ESHUTDOWN;
+               goto exit;
+       }
+
+       if (usb_endpoint_xfer_isoc(&urb->ep->desc))
+               size = urb->number_of_packets;
+       else
+               size = 1;
+
+       urb_priv = kzalloc(sizeof(struct urb_priv) +
+                                 size * sizeof(struct xhci_td *), mem_flags);
+       if (!urb_priv)
+               return -ENOMEM;
+
+       buffer = kzalloc(size * sizeof(struct xhci_td), mem_flags);
+       if (!buffer) {
+               kfree(urb_priv);
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < size; i++) {
+               urb_priv->td[i] = buffer;
+               buffer++;
+       }
+
+       urb_priv->length = size;
+       urb_priv->td_cnt = 0;
+       urb->hcpriv = urb_priv;
+
+       if (usb_endpoint_xfer_control(&urb->ep->desc)) {
+               /* Check to see if the max packet size for the default control
+                * endpoint changed during FS device enumeration
+                */
+               if (urb->dev->speed == USB_SPEED_FULL) {
+                       ret = xhci_check_maxpacket(xhci, slot_id,
+                                       ep_index, urb);
+                       if (ret < 0) {
+                               xhci_urb_free_priv(urb_priv);
+                               urb->hcpriv = NULL;
+                               return ret;
+                       }
+               }
+
+               /* We have a spinlock and interrupts disabled, so we must pass
+                * atomic context to this function, which may allocate memory.
+                */
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_ctrl_tx(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               if (ret)
+                       goto free_priv;
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else if (usb_endpoint_xfer_bulk(&urb->ep->desc)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               if (xhci->devs[slot_id]->eps[ep_index].ep_state &
+                               EP_GETTING_STREAMS) {
+                       xhci_warn(xhci, "WARN: Can't enqueue URB while bulk ep "
+                                       "is transitioning to using streams.\n");
+                       ret = -EINVAL;
+               } else if (xhci->devs[slot_id]->eps[ep_index].ep_state &
+                               EP_GETTING_NO_STREAMS) {
+                       xhci_warn(xhci, "WARN: Can't enqueue URB while bulk ep "
+                                       "is transitioning to "
+                                       "not having streams.\n");
+                       ret = -EINVAL;
+               } else {
+                       ret = xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb,
+                                       slot_id, ep_index);
+               }
+               if (ret)
+                       goto free_priv;
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else if (usb_endpoint_xfer_int(&urb->ep->desc)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_intr_tx(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               if (ret)
+                       goto free_priv;
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else {
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_isoc_tx_prepare(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               if (ret)
+                       goto free_priv;
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       }
+exit:
+       return ret;
+dying:
+       xhci_dbg(xhci, "Ep 0x%x: URB %p submitted for "
+                       "non-responsive xHCI host.\n",
+                       urb->ep->desc.bEndpointAddress, urb);
+       ret = -ESHUTDOWN;
+free_priv:
+       xhci_urb_free_priv(urb_priv);
+       urb->hcpriv = NULL;
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return ret;
+}
+
+/* Get the right ring for the given URB.
+ * If the endpoint supports streams, boundary check the URB's stream ID.
+ * If the endpoint doesn't support streams, return the singular endpoint ring.
+ */
+static struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
+               struct urb *urb)
+{
+       unsigned int slot_id;
+       unsigned int ep_index;
+       unsigned int stream_id;
+       struct xhci_virt_ep *ep;
+
+       slot_id = urb->dev->slot_id;
+       ep_index = xhci_get_endpoint_index(&urb->ep->desc);
+       stream_id = urb->stream_id;
+       ep = &xhci->devs[slot_id]->eps[ep_index];
+       /* Common case: no streams */
+       if (!(ep->ep_state & EP_HAS_STREAMS))
+               return ep->ring;
+
+       if (stream_id == 0) {
+               xhci_warn(xhci,
+                               "WARN: Slot ID %u, ep index %u has streams, "
+                               "but URB has no stream ID.\n",
+                               slot_id, ep_index);
+               return NULL;
+       }
+
+       if (stream_id < ep->stream_info->num_streams)
+               return ep->stream_info->stream_rings[stream_id];
+
+       xhci_warn(xhci,
+                       "WARN: Slot ID %u, ep index %u has "
+                       "stream IDs 1 to %u allocated, "
+                       "but stream ID %u is requested.\n",
+                       slot_id, ep_index,
+                       ep->stream_info->num_streams - 1,
+                       stream_id);
+       return NULL;
+}
+
+/*
+ * Remove the URB's TD from the endpoint ring.  This may cause the HC to stop
+ * USB transfers, potentially stopping in the middle of a TRB buffer.  The HC
+ * should pick up where it left off in the TD, unless a Set Transfer Ring
+ * Dequeue Pointer is issued.
+ *
+ * The TRBs that make up the buffers for the canceled URB will be "removed" from
+ * the ring.  Since the ring is a contiguous structure, they can't be physically
+ * removed.  Instead, there are two options:
+ *
+ *  1) If the HC is in the middle of processing the URB to be canceled, we
+ *     simply move the ring's dequeue pointer past those TRBs using the Set
+ *     Transfer Ring Dequeue Pointer command.  This will be the common case,
+ *     when drivers timeout on the last submitted URB and attempt to cancel.
+ *
+ *  2) If the HC is in the middle of a different TD, we turn the TRBs into a
+ *     series of 1-TRB transfer no-op TDs.  (No-ops shouldn't be chained.)  The
+ *     HC will need to invalidate the any TRBs it has cached after the stop
+ *     endpoint command, as noted in the xHCI 0.95 errata.
+ *
+ *  3) The TD may have completed by the time the Stop Endpoint Command
+ *     completes, so software needs to handle that case too.
+ *
+ * This function should protect against the TD enqueueing code ringing the
+ * doorbell while this code is waiting for a Stop Endpoint command to complete.
+ * It also needs to account for multiple cancellations on happening at the same
+ * time for the same endpoint.
+ *
+ * Note that this function can be called in any context, or so says
+ * usb_hcd_unlink_urb()
+ */
+int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+       unsigned long flags;
+       int ret, i;
+       u32 temp;
+       struct xhci_hcd *xhci;
+       struct urb_priv *urb_priv;
+       struct xhci_td *td;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+       struct xhci_virt_ep *ep;
+       struct xhci_command *command;
+
+       xhci = hcd_to_xhci(hcd);
+       spin_lock_irqsave(&xhci->lock, flags);
+       /* Make sure the URB hasn't completed or been unlinked already */
+       ret = usb_hcd_check_unlink_urb(hcd, urb, status);
+       if (ret || !urb->hcpriv)
+               goto done;
+       temp = readl(&xhci->op_regs->status);
+       if (temp == 0xffffffff || (xhci->xhc_state & XHCI_STATE_HALTED)) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
+                               "HW died, freeing TD.");
+               urb_priv = urb->hcpriv;
+               for (i = urb_priv->td_cnt; i < urb_priv->length; i++) {
+                       td = urb_priv->td[i];
+                       if (!list_empty(&td->td_list))
+                               list_del_init(&td->td_list);
+                       if (!list_empty(&td->cancelled_td_list))
+                               list_del_init(&td->cancelled_td_list);
+               }
+
+               usb_hcd_unlink_urb_from_ep(hcd, urb);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               usb_hcd_giveback_urb(hcd, urb, -ESHUTDOWN);
+               xhci_urb_free_priv(urb_priv);
+               return ret;
+       }
+       if ((xhci->xhc_state & XHCI_STATE_DYING) ||
+                       (xhci->xhc_state & XHCI_STATE_HALTED)) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
+                               "Ep 0x%x: URB %p to be canceled on "
+                               "non-responsive xHCI host.",
+                               urb->ep->desc.bEndpointAddress, urb);
+               /* Let the stop endpoint command watchdog timer (which set this
+                * state) finish cleaning up the endpoint TD lists.  We must
+                * have caught it in the middle of dropping a lock and giving
+                * back an URB.
+                */
+               goto done;
+       }
+
+       ep_index = xhci_get_endpoint_index(&urb->ep->desc);
+       ep = &xhci->devs[urb->dev->slot_id]->eps[ep_index];
+       ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
+       if (!ep_ring) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       urb_priv = urb->hcpriv;
+       i = urb_priv->td_cnt;
+       if (i < urb_priv->length)
+               xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
+                               "Cancel URB %p, dev %s, ep 0x%x, "
+                               "starting at offset 0x%llx",
+                               urb, urb->dev->devpath,
+                               urb->ep->desc.bEndpointAddress,
+                               (unsigned long long) xhci_trb_virt_to_dma(
+                                       urb_priv->td[i]->start_seg,
+                                       urb_priv->td[i]->first_trb));
+
+       for (; i < urb_priv->length; i++) {
+               td = urb_priv->td[i];
+               list_add_tail(&td->cancelled_td_list, &ep->cancelled_td_list);
+       }
+
+       /* Queue a stop endpoint command, but only if this is
+        * the first cancellation to be handled.
+        */
+       if (!(ep->ep_state & EP_HALT_PENDING)) {
+               command = xhci_alloc_command(xhci, false, false, GFP_ATOMIC);
+               if (!command) {
+                       ret = -ENOMEM;
+                       goto done;
+               }
+               ep->ep_state |= EP_HALT_PENDING;
+               ep->stop_cmds_pending++;
+               ep->stop_cmd_timer.expires = jiffies +
+                       XHCI_STOP_EP_CMD_TIMEOUT * HZ;
+               add_timer(&ep->stop_cmd_timer);
+               xhci_queue_stop_endpoint(xhci, command, urb->dev->slot_id,
+                                        ep_index, 0);
+               xhci_ring_cmd_db(xhci);
+       }
+done:
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return ret;
+}
+
+/* Drop an endpoint from a new bandwidth configuration for this device.
+ * Only one call to this function is allowed per endpoint before
+ * check_bandwidth() or reset_bandwidth() must be called.
+ * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
+ * add the endpoint to the schedule with possibly new parameters denoted by a
+ * different endpoint descriptor in usb_host_endpoint.
+ * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
+ * not allowed.
+ *
+ * The USB core will not allow URBs to be queued to an endpoint that is being
+ * disabled, so there's no need for mutual exclusion to protect
+ * the xhci->devs[slot_id] structure.
+ */
+int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_container_ctx *in_ctx, *out_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       unsigned int ep_index;
+       struct xhci_ep_ctx *ep_ctx;
+       u32 drop_flag;
+       u32 new_add_flags, new_drop_flags;
+       int ret;
+
+       ret = xhci_check_args(hcd, udev, ep, 1, true, __func__);
+       if (ret <= 0)
+               return ret;
+       xhci = hcd_to_xhci(hcd);
+       if (xhci->xhc_state & XHCI_STATE_DYING)
+               return -ENODEV;
+
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+       drop_flag = xhci_get_endpoint_flag(&ep->desc);
+       if (drop_flag == SLOT_FLAG || drop_flag == EP0_FLAG) {
+               xhci_dbg(xhci, "xHCI %s - can't drop slot or ep 0 %#x\n",
+                               __func__, drop_flag);
+               return 0;
+       }
+
+       in_ctx = xhci->devs[udev->slot_id]->in_ctx;
+       out_ctx = xhci->devs[udev->slot_id]->out_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return 0;
+       }
+
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
+       /* If the HC already knows the endpoint is disabled,
+        * or the HCD has noted it is disabled, ignore this request
+        */
+       if (((ep_ctx->ep_info & cpu_to_le32(EP_STATE_MASK)) ==
+            cpu_to_le32(EP_STATE_DISABLED)) ||
+           le32_to_cpu(ctrl_ctx->drop_flags) &
+           xhci_get_endpoint_flag(&ep->desc)) {
+               /* Do not warn when called after a usb_device_reset */
+               if (xhci->devs[udev->slot_id]->eps[ep_index].ring != NULL)
+                       xhci_warn(xhci, "xHCI %s called with disabled ep %p\n",
+                                 __func__, ep);
+               return 0;
+       }
+
+       ctrl_ctx->drop_flags |= cpu_to_le32(drop_flag);
+       new_drop_flags = le32_to_cpu(ctrl_ctx->drop_flags);
+
+       ctrl_ctx->add_flags &= cpu_to_le32(~drop_flag);
+       new_add_flags = le32_to_cpu(ctrl_ctx->add_flags);
+
+       xhci_endpoint_zero(xhci, xhci->devs[udev->slot_id], ep);
+
+       xhci_dbg(xhci, "drop ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",
+                       (unsigned int) ep->desc.bEndpointAddress,
+                       udev->slot_id,
+                       (unsigned int) new_drop_flags,
+                       (unsigned int) new_add_flags);
+       return 0;
+}
+
+/* Add an endpoint to a new possible bandwidth configuration for this device.
+ * Only one call to this function is allowed per endpoint before
+ * check_bandwidth() or reset_bandwidth() must be called.
+ * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
+ * add the endpoint to the schedule with possibly new parameters denoted by a
+ * different endpoint descriptor in usb_host_endpoint.
+ * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
+ * not allowed.
+ *
+ * The USB core will not allow URBs to be queued to an endpoint until the
+ * configuration or alt setting is installed in the device, so there's no need
+ * for mutual exclusion to protect the xhci->devs[slot_id] structure.
+ */
+int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_container_ctx *in_ctx;
+       unsigned int ep_index;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       u32 added_ctxs;
+       u32 new_add_flags, new_drop_flags;
+       struct xhci_virt_device *virt_dev;
+       int ret = 0;
+
+       ret = xhci_check_args(hcd, udev, ep, 1, true, __func__);
+       if (ret <= 0) {
+               /* So we won't queue a reset ep command for a root hub */
+               ep->hcpriv = NULL;
+               return ret;
+       }
+       xhci = hcd_to_xhci(hcd);
+       if (xhci->xhc_state & XHCI_STATE_DYING)
+               return -ENODEV;
+
+       added_ctxs = xhci_get_endpoint_flag(&ep->desc);
+       if (added_ctxs == SLOT_FLAG || added_ctxs == EP0_FLAG) {
+               /* FIXME when we have to issue an evaluate endpoint command to
+                * deal with ep0 max packet size changing once we get the
+                * descriptors
+                */
+               xhci_dbg(xhci, "xHCI %s - can't add slot or ep 0 %#x\n",
+                               __func__, added_ctxs);
+               return 0;
+       }
+
+       virt_dev = xhci->devs[udev->slot_id];
+       in_ctx = virt_dev->in_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return 0;
+       }
+
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       /* If this endpoint is already in use, and the upper layers are trying
+        * to add it again without dropping it, reject the addition.
+        */
+       if (virt_dev->eps[ep_index].ring &&
+                       !(le32_to_cpu(ctrl_ctx->drop_flags) & added_ctxs)) {
+               xhci_warn(xhci, "Trying to add endpoint 0x%x "
+                               "without dropping it.\n",
+                               (unsigned int) ep->desc.bEndpointAddress);
+               return -EINVAL;
+       }
+
+       /* If the HCD has already noted the endpoint is enabled,
+        * ignore this request.
+        */
+       if (le32_to_cpu(ctrl_ctx->add_flags) & added_ctxs) {
+               xhci_warn(xhci, "xHCI %s called with enabled ep %p\n",
+                               __func__, ep);
+               return 0;
+       }
+
+       /*
+        * Configuration and alternate setting changes must be done in
+        * process context, not interrupt context (or so documenation
+        * for usb_set_interface() and usb_set_configuration() claim).
+        */
+       if (xhci_endpoint_init(xhci, virt_dev, udev, ep, GFP_NOIO) < 0) {
+               dev_dbg(&udev->dev, "%s - could not initialize ep %#x\n",
+                               __func__, ep->desc.bEndpointAddress);
+               return -ENOMEM;
+       }
+
+       ctrl_ctx->add_flags |= cpu_to_le32(added_ctxs);
+       new_add_flags = le32_to_cpu(ctrl_ctx->add_flags);
+
+       /* If xhci_endpoint_disable() was called for this endpoint, but the
+        * xHC hasn't been notified yet through the check_bandwidth() call,
+        * this re-adds a new state for the endpoint from the new endpoint
+        * descriptors.  We must drop and re-add this endpoint, so we leave the
+        * drop flags alone.
+        */
+       new_drop_flags = le32_to_cpu(ctrl_ctx->drop_flags);
+
+       /* Store the usb_device pointer for later use */
+       ep->hcpriv = udev;
+
+       xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",
+                       (unsigned int) ep->desc.bEndpointAddress,
+                       udev->slot_id,
+                       (unsigned int) new_drop_flags,
+                       (unsigned int) new_add_flags);
+       return 0;
+}
+
+static void xhci_zero_in_ctx(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev)
+{
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       int i;
+
+       ctrl_ctx = xhci_get_input_control_ctx(virt_dev->in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return;
+       }
+
+       /* When a device's add flag and drop flag are zero, any subsequent
+        * configure endpoint command will leave that endpoint's state
+        * untouched.  Make sure we don't leave any old state in the input
+        * endpoint contexts.
+        */
+       ctrl_ctx->drop_flags = 0;
+       ctrl_ctx->add_flags = 0;
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+       slot_ctx->dev_info &= cpu_to_le32(~LAST_CTX_MASK);
+       /* Endpoint 0 is always valid */
+       slot_ctx->dev_info |= cpu_to_le32(LAST_CTX(1));
+       for (i = 1; i < 31; ++i) {
+               ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, i);
+               ep_ctx->ep_info = 0;
+               ep_ctx->ep_info2 = 0;
+               ep_ctx->deq = 0;
+               ep_ctx->tx_info = 0;
+       }
+}
+
+static int xhci_configure_endpoint_result(struct xhci_hcd *xhci,
+               struct usb_device *udev, u32 *cmd_status)
+{
+       int ret;
+
+       switch (*cmd_status) {
+       case COMP_CMD_ABORT:
+       case COMP_CMD_STOP:
+               xhci_warn(xhci, "Timeout while waiting for configure endpoint command\n");
+               ret = -ETIME;
+               break;
+       case COMP_ENOMEM:
+               dev_warn(&udev->dev,
+                        "Not enough host controller resources for new device state.\n");
+               ret = -ENOMEM;
+               /* FIXME: can we allocate more resources for the HC? */
+               break;
+       case COMP_BW_ERR:
+       case COMP_2ND_BW_ERR:
+               dev_warn(&udev->dev,
+                        "Not enough bandwidth for new device state.\n");
+               ret = -ENOSPC;
+               /* FIXME: can we go back to the old state? */
+               break;
+       case COMP_TRB_ERR:
+               /* the HCD set up something wrong */
+               dev_warn(&udev->dev, "ERROR: Endpoint drop flag = 0, "
+                               "add flag = 1, "
+                               "and endpoint is not disabled.\n");
+               ret = -EINVAL;
+               break;
+       case COMP_DEV_ERR:
+               dev_warn(&udev->dev,
+                        "ERROR: Incompatible device for endpoint configure command.\n");
+               ret = -ENODEV;
+               break;
+       case COMP_SUCCESS:
+               xhci_dbg_trace(xhci, trace_xhci_dbg_context_change,
+                               "Successful Endpoint Configure command");
+               ret = 0;
+               break;
+       default:
+               xhci_err(xhci, "ERROR: unexpected command completion code 0x%x.\n",
+                               *cmd_status);
+               ret = -EINVAL;
+               break;
+       }
+       return ret;
+}
+
+static int xhci_evaluate_context_result(struct xhci_hcd *xhci,
+               struct usb_device *udev, u32 *cmd_status)
+{
+       int ret;
+       struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];
+
+       switch (*cmd_status) {
+       case COMP_CMD_ABORT:
+       case COMP_CMD_STOP:
+               xhci_warn(xhci, "Timeout while waiting for evaluate context command\n");
+               ret = -ETIME;
+               break;
+       case COMP_EINVAL:
+               dev_warn(&udev->dev,
+                        "WARN: xHCI driver setup invalid evaluate context command.\n");
+               ret = -EINVAL;
+               break;
+       case COMP_EBADSLT:
+               dev_warn(&udev->dev,
+                       "WARN: slot not enabled for evaluate context command.\n");
+               ret = -EINVAL;
+               break;
+       case COMP_CTX_STATE:
+               dev_warn(&udev->dev,
+                       "WARN: invalid context state for evaluate context command.\n");
+               xhci_dbg_ctx(xhci, virt_dev->out_ctx, 1);
+               ret = -EINVAL;
+               break;
+       case COMP_DEV_ERR:
+               dev_warn(&udev->dev,
+                       "ERROR: Incompatible device for evaluate context command.\n");
+               ret = -ENODEV;
+               break;
+       case COMP_MEL_ERR:
+               /* Max Exit Latency too large error */
+               dev_warn(&udev->dev, "WARN: Max Exit Latency too large\n");
+               ret = -EINVAL;
+               break;
+       case COMP_SUCCESS:
+               xhci_dbg_trace(xhci, trace_xhci_dbg_context_change,
+                               "Successful evaluate context command");
+               ret = 0;
+               break;
+       default:
+               xhci_err(xhci, "ERROR: unexpected command completion code 0x%x.\n",
+                       *cmd_status);
+               ret = -EINVAL;
+               break;
+       }
+       return ret;
+}
+
+static u32 xhci_count_num_new_endpoints(struct xhci_hcd *xhci,
+               struct xhci_input_control_ctx *ctrl_ctx)
+{
+       u32 valid_add_flags;
+       u32 valid_drop_flags;
+
+       /* Ignore the slot flag (bit 0), and the default control endpoint flag
+        * (bit 1).  The default control endpoint is added during the Address
+        * Device command and is never removed until the slot is disabled.
+        */
+       valid_add_flags = le32_to_cpu(ctrl_ctx->add_flags) >> 2;
+       valid_drop_flags = le32_to_cpu(ctrl_ctx->drop_flags) >> 2;
+
+       /* Use hweight32 to count the number of ones in the add flags, or
+        * number of endpoints added.  Don't count endpoints that are changed
+        * (both added and dropped).
+        */
+       return hweight32(valid_add_flags) -
+               hweight32(valid_add_flags & valid_drop_flags);
+}
+
+static unsigned int xhci_count_num_dropped_endpoints(struct xhci_hcd *xhci,
+               struct xhci_input_control_ctx *ctrl_ctx)
+{
+       u32 valid_add_flags;
+       u32 valid_drop_flags;
+
+       valid_add_flags = le32_to_cpu(ctrl_ctx->add_flags) >> 2;
+       valid_drop_flags = le32_to_cpu(ctrl_ctx->drop_flags) >> 2;
+
+       return hweight32(valid_drop_flags) -
+               hweight32(valid_add_flags & valid_drop_flags);
+}
+
+/*
+ * We need to reserve the new number of endpoints before the configure endpoint
+ * command completes.  We can't subtract the dropped endpoints from the number
+ * of active endpoints until the command completes because we can oversubscribe
+ * the host in this case:
+ *
+ *  - the first configure endpoint command drops more endpoints than it adds
+ *  - a second configure endpoint command that adds more endpoints is queued
+ *  - the first configure endpoint command fails, so the config is unchanged
+ *  - the second command may succeed, even though there isn't enough resources
+ *
+ * Must be called with xhci->lock held.
+ */
+static int xhci_reserve_host_resources(struct xhci_hcd *xhci,
+               struct xhci_input_control_ctx *ctrl_ctx)
+{
+       u32 added_eps;
+
+       added_eps = xhci_count_num_new_endpoints(xhci, ctrl_ctx);
+       if (xhci->num_active_eps + added_eps > xhci->limit_active_eps) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Not enough ep ctxs: "
+                               "%u active, need to add %u, limit is %u.",
+                               xhci->num_active_eps, added_eps,
+                               xhci->limit_active_eps);
+               return -ENOMEM;
+       }
+       xhci->num_active_eps += added_eps;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                       "Adding %u ep ctxs, %u now active.", added_eps,
+                       xhci->num_active_eps);
+       return 0;
+}
+
+/*
+ * The configure endpoint was failed by the xHC for some other reason, so we
+ * need to revert the resources that failed configuration would have used.
+ *
+ * Must be called with xhci->lock held.
+ */
+static void xhci_free_host_resources(struct xhci_hcd *xhci,
+               struct xhci_input_control_ctx *ctrl_ctx)
+{
+       u32 num_failed_eps;
+
+       num_failed_eps = xhci_count_num_new_endpoints(xhci, ctrl_ctx);
+       xhci->num_active_eps -= num_failed_eps;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                       "Removing %u failed ep ctxs, %u now active.",
+                       num_failed_eps,
+                       xhci->num_active_eps);
+}
+
+/*
+ * Now that the command has completed, clean up the active endpoint count by
+ * subtracting out the endpoints that were dropped (but not changed).
+ *
+ * Must be called with xhci->lock held.
+ */
+static void xhci_finish_resource_reservation(struct xhci_hcd *xhci,
+               struct xhci_input_control_ctx *ctrl_ctx)
+{
+       u32 num_dropped_eps;
+
+       num_dropped_eps = xhci_count_num_dropped_endpoints(xhci, ctrl_ctx);
+       xhci->num_active_eps -= num_dropped_eps;
+       if (num_dropped_eps)
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Removing %u dropped ep ctxs, %u now active.",
+                               num_dropped_eps,
+                               xhci->num_active_eps);
+}
+
+static unsigned int xhci_get_block_size(struct usb_device *udev)
+{
+       switch (udev->speed) {
+       case USB_SPEED_LOW:
+       case USB_SPEED_FULL:
+               return FS_BLOCK;
+       case USB_SPEED_HIGH:
+               return HS_BLOCK;
+       case USB_SPEED_SUPER:
+               return SS_BLOCK;
+       case USB_SPEED_UNKNOWN:
+       case USB_SPEED_WIRELESS:
+       default:
+               /* Should never happen */
+               return 1;
+       }
+}
+
+static unsigned int
+xhci_get_largest_overhead(struct xhci_interval_bw *interval_bw)
+{
+       if (interval_bw->overhead[LS_OVERHEAD_TYPE])
+               return LS_OVERHEAD;
+       if (interval_bw->overhead[FS_OVERHEAD_TYPE])
+               return FS_OVERHEAD;
+       return HS_OVERHEAD;
+}
+
+/* If we are changing a LS/FS device under a HS hub,
+ * make sure (if we are activating a new TT) that the HS bus has enough
+ * bandwidth for this new TT.
+ */
+static int xhci_check_tt_bw_table(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev,
+               int old_active_eps)
+{
+       struct xhci_interval_bw_table *bw_table;
+       struct xhci_tt_bw_info *tt_info;
+
+       /* Find the bandwidth table for the root port this TT is attached to. */
+       bw_table = &xhci->rh_bw[virt_dev->real_port - 1].bw_table;
+       tt_info = virt_dev->tt_info;
+       /* If this TT already had active endpoints, the bandwidth for this TT
+        * has already been added.  Removing all periodic endpoints (and thus
+        * making the TT enactive) will only decrease the bandwidth used.
+        */
+       if (old_active_eps)
+               return 0;
+       if (old_active_eps == 0 && tt_info->active_eps != 0) {
+               if (bw_table->bw_used + TT_HS_OVERHEAD > HS_BW_LIMIT)
+                       return -ENOMEM;
+               return 0;
+       }
+       /* Not sure why we would have no new active endpoints...
+        *
+        * Maybe because of an Evaluate Context change for a hub update or a
+        * control endpoint 0 max packet size change?
+        * FIXME: skip the bandwidth calculation in that case.
+        */
+       return 0;
+}
+
+static int xhci_check_ss_bw(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev)
+{
+       unsigned int bw_reserved;
+
+       bw_reserved = DIV_ROUND_UP(SS_BW_RESERVED*SS_BW_LIMIT_IN, 100);
+       if (virt_dev->bw_table->ss_bw_in > (SS_BW_LIMIT_IN - bw_reserved))
+               return -ENOMEM;
+
+       bw_reserved = DIV_ROUND_UP(SS_BW_RESERVED*SS_BW_LIMIT_OUT, 100);
+       if (virt_dev->bw_table->ss_bw_out > (SS_BW_LIMIT_OUT - bw_reserved))
+               return -ENOMEM;
+
+       return 0;
+}
+
+/*
+ * This algorithm is a very conservative estimate of the worst-case scheduling
+ * scenario for any one interval.  The hardware dynamically schedules the
+ * packets, so we can't tell which microframe could be the limiting factor in
+ * the bandwidth scheduling.  This only takes into account periodic endpoints.
+ *
+ * Obviously, we can't solve an NP complete problem to find the minimum worst
+ * case scenario.  Instead, we come up with an estimate that is no less than
+ * the worst case bandwidth used for any one microframe, but may be an
+ * over-estimate.
+ *
+ * We walk the requirements for each endpoint by interval, starting with the
+ * smallest interval, and place packets in the schedule where there is only one
+ * possible way to schedule packets for that interval.  In order to simplify
+ * this algorithm, we record the largest max packet size for each interval, and
+ * assume all packets will be that size.
+ *
+ * For interval 0, we obviously must schedule all packets for each interval.
+ * The bandwidth for interval 0 is just the amount of data to be transmitted
+ * (the sum of all max ESIT payload sizes, plus any overhead per packet times
+ * the number of packets).
+ *
+ * For interval 1, we have two possible microframes to schedule those packets
+ * in.  For this algorithm, if we can schedule the same number of packets for
+ * each possible scheduling opportunity (each microframe), we will do so.  The
+ * remaining number of packets will be saved to be transmitted in the gaps in
+ * the next interval's scheduling sequence.
+ *
+ * As we move those remaining packets to be scheduled with interval 2 packets,
+ * we have to double the number of remaining packets to transmit.  This is
+ * because the intervals are actually powers of 2, and we would be transmitting
+ * the previous interval's packets twice in this interval.  We also have to be
+ * sure that when we look at the largest max packet size for this interval, we
+ * also look at the largest max packet size for the remaining packets and take
+ * the greater of the two.
+ *
+ * The algorithm continues to evenly distribute packets in each scheduling
+ * opportunity, and push the remaining packets out, until we get to the last
+ * interval.  Then those packets and their associated overhead are just added
+ * to the bandwidth used.
+ */
+static int xhci_check_bw_table(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev,
+               int old_active_eps)
+{
+       unsigned int bw_reserved;
+       unsigned int max_bandwidth;
+       unsigned int bw_used;
+       unsigned int block_size;
+       struct xhci_interval_bw_table *bw_table;
+       unsigned int packet_size = 0;
+       unsigned int overhead = 0;
+       unsigned int packets_transmitted = 0;
+       unsigned int packets_remaining = 0;
+       unsigned int i;
+
+       if (virt_dev->udev->speed == USB_SPEED_SUPER)
+               return xhci_check_ss_bw(xhci, virt_dev);
+
+       if (virt_dev->udev->speed == USB_SPEED_HIGH) {
+               max_bandwidth = HS_BW_LIMIT;
+               /* Convert percent of bus BW reserved to blocks reserved */
+               bw_reserved = DIV_ROUND_UP(HS_BW_RESERVED * max_bandwidth, 100);
+       } else {
+               max_bandwidth = FS_BW_LIMIT;
+               bw_reserved = DIV_ROUND_UP(FS_BW_RESERVED * max_bandwidth, 100);
+       }
+
+       bw_table = virt_dev->bw_table;
+       /* We need to translate the max packet size and max ESIT payloads into
+        * the units the hardware uses.
+        */
+       block_size = xhci_get_block_size(virt_dev->udev);
+
+       /* If we are manipulating a LS/FS device under a HS hub, double check
+        * that the HS bus has enough bandwidth if we are activing a new TT.
+        */
+       if (virt_dev->tt_info) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Recalculating BW for rootport %u",
+                               virt_dev->real_port);
+               if (xhci_check_tt_bw_table(xhci, virt_dev, old_active_eps)) {
+                       xhci_warn(xhci, "Not enough bandwidth on HS bus for "
+                                       "newly activated TT.\n");
+                       return -ENOMEM;
+               }
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Recalculating BW for TT slot %u port %u",
+                               virt_dev->tt_info->slot_id,
+                               virt_dev->tt_info->ttport);
+       } else {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Recalculating BW for rootport %u",
+                               virt_dev->real_port);
+       }
+
+       /* Add in how much bandwidth will be used for interval zero, or the
+        * rounded max ESIT payload + number of packets * largest overhead.
+        */
+       bw_used = DIV_ROUND_UP(bw_table->interval0_esit_payload, block_size) +
+               bw_table->interval_bw[0].num_packets *
+               xhci_get_largest_overhead(&bw_table->interval_bw[0]);
+
+       for (i = 1; i < XHCI_MAX_INTERVAL; i++) {
+               unsigned int bw_added;
+               unsigned int largest_mps;
+               unsigned int interval_overhead;
+
+               /*
+                * How many packets could we transmit in this interval?
+                * If packets didn't fit in the previous interval, we will need
+                * to transmit that many packets twice within this interval.
+                */
+               packets_remaining = 2 * packets_remaining +
+                       bw_table->interval_bw[i].num_packets;
+
+               /* Find the largest max packet size of this or the previous
+                * interval.
+                */
+               if (list_empty(&bw_table->interval_bw[i].endpoints))
+                       largest_mps = 0;
+               else {
+                       struct xhci_virt_ep *virt_ep;
+                       struct list_head *ep_entry;
+
+                       ep_entry = bw_table->interval_bw[i].endpoints.next;
+                       virt_ep = list_entry(ep_entry,
+                                       struct xhci_virt_ep, bw_endpoint_list);
+                       /* Convert to blocks, rounding up */
+                       largest_mps = DIV_ROUND_UP(
+                                       virt_ep->bw_info.max_packet_size,
+                                       block_size);
+               }
+               if (largest_mps > packet_size)
+                       packet_size = largest_mps;
+
+               /* Use the larger overhead of this or the previous interval. */
+               interval_overhead = xhci_get_largest_overhead(
+                               &bw_table->interval_bw[i]);
+               if (interval_overhead > overhead)
+                       overhead = interval_overhead;
+
+               /* How many packets can we evenly distribute across
+                * (1 << (i + 1)) possible scheduling opportunities?
+                */
+               packets_transmitted = packets_remaining >> (i + 1);
+
+               /* Add in the bandwidth used for those scheduled packets */
+               bw_added = packets_transmitted * (overhead + packet_size);
+
+               /* How many packets do we have remaining to transmit? */
+               packets_remaining = packets_remaining % (1 << (i + 1));
+
+               /* What largest max packet size should those packets have? */
+               /* If we've transmitted all packets, don't carry over the
+                * largest packet size.
+                */
+               if (packets_remaining == 0) {
+                       packet_size = 0;
+                       overhead = 0;
+               } else if (packets_transmitted > 0) {
+                       /* Otherwise if we do have remaining packets, and we've
+                        * scheduled some packets in this interval, take the
+                        * largest max packet size from endpoints with this
+                        * interval.
+                        */
+                       packet_size = largest_mps;
+                       overhead = interval_overhead;
+               }
+               /* Otherwise carry over packet_size and overhead from the last
+                * time we had a remainder.
+                */
+               bw_used += bw_added;
+               if (bw_used > max_bandwidth) {
+                       xhci_warn(xhci, "Not enough bandwidth. "
+                                       "Proposed: %u, Max: %u\n",
+                               bw_used, max_bandwidth);
+                       return -ENOMEM;
+               }
+       }
+       /*
+        * Ok, we know we have some packets left over after even-handedly
+        * scheduling interval 15.  We don't know which microframes they will
+        * fit into, so we over-schedule and say they will be scheduled every
+        * microframe.
+        */
+       if (packets_remaining > 0)
+               bw_used += overhead + packet_size;
+
+       if (!virt_dev->tt_info && virt_dev->udev->speed == USB_SPEED_HIGH) {
+               unsigned int port_index = virt_dev->real_port - 1;
+
+               /* OK, we're manipulating a HS device attached to a
+                * root port bandwidth domain.  Include the number of active TTs
+                * in the bandwidth used.
+                */
+               bw_used += TT_HS_OVERHEAD *
+                       xhci->rh_bw[port_index].num_active_tts;
+       }
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+               "Final bandwidth: %u, Limit: %u, Reserved: %u, "
+               "Available: %u " "percent",
+               bw_used, max_bandwidth, bw_reserved,
+               (max_bandwidth - bw_used - bw_reserved) * 100 /
+               max_bandwidth);
+
+       bw_used += bw_reserved;
+       if (bw_used > max_bandwidth) {
+               xhci_warn(xhci, "Not enough bandwidth. Proposed: %u, Max: %u\n",
+                               bw_used, max_bandwidth);
+               return -ENOMEM;
+       }
+
+       bw_table->bw_used = bw_used;
+       return 0;
+}
+
+static bool xhci_is_async_ep(unsigned int ep_type)
+{
+       return (ep_type != ISOC_OUT_EP && ep_type != INT_OUT_EP &&
+                                       ep_type != ISOC_IN_EP &&
+                                       ep_type != INT_IN_EP);
+}
+
+static bool xhci_is_sync_in_ep(unsigned int ep_type)
+{
+       return (ep_type == ISOC_IN_EP || ep_type == INT_IN_EP);
+}
+
+static unsigned int xhci_get_ss_bw_consumed(struct xhci_bw_info *ep_bw)
+{
+       unsigned int mps = DIV_ROUND_UP(ep_bw->max_packet_size, SS_BLOCK);
+
+       if (ep_bw->ep_interval == 0)
+               return SS_OVERHEAD_BURST +
+                       (ep_bw->mult * ep_bw->num_packets *
+                                       (SS_OVERHEAD + mps));
+       return DIV_ROUND_UP(ep_bw->mult * ep_bw->num_packets *
+                               (SS_OVERHEAD + mps + SS_OVERHEAD_BURST),
+                               1 << ep_bw->ep_interval);
+
+}
+
+void xhci_drop_ep_from_interval_table(struct xhci_hcd *xhci,
+               struct xhci_bw_info *ep_bw,
+               struct xhci_interval_bw_table *bw_table,
+               struct usb_device *udev,
+               struct xhci_virt_ep *virt_ep,
+               struct xhci_tt_bw_info *tt_info)
+{
+       struct xhci_interval_bw *interval_bw;
+       int normalized_interval;
+
+       if (xhci_is_async_ep(ep_bw->type))
+               return;
+
+       if (udev->speed == USB_SPEED_SUPER) {
+               if (xhci_is_sync_in_ep(ep_bw->type))
+                       xhci->devs[udev->slot_id]->bw_table->ss_bw_in -=
+                               xhci_get_ss_bw_consumed(ep_bw);
+               else
+                       xhci->devs[udev->slot_id]->bw_table->ss_bw_out -=
+                               xhci_get_ss_bw_consumed(ep_bw);
+               return;
+       }
+
+       /* SuperSpeed endpoints never get added to intervals in the table, so
+        * this check is only valid for HS/FS/LS devices.
+        */
+       if (list_empty(&virt_ep->bw_endpoint_list))
+               return;
+       /* For LS/FS devices, we need to translate the interval expressed in
+        * microframes to frames.
+        */
+       if (udev->speed == USB_SPEED_HIGH)
+               normalized_interval = ep_bw->ep_interval;
+       else
+               normalized_interval = ep_bw->ep_interval - 3;
+
+       if (normalized_interval == 0)
+               bw_table->interval0_esit_payload -= ep_bw->max_esit_payload;
+       interval_bw = &bw_table->interval_bw[normalized_interval];
+       interval_bw->num_packets -= ep_bw->num_packets;
+       switch (udev->speed) {
+       case USB_SPEED_LOW:
+               interval_bw->overhead[LS_OVERHEAD_TYPE] -= 1;
+               break;
+       case USB_SPEED_FULL:
+               interval_bw->overhead[FS_OVERHEAD_TYPE] -= 1;
+               break;
+       case USB_SPEED_HIGH:
+               interval_bw->overhead[HS_OVERHEAD_TYPE] -= 1;
+               break;
+       case USB_SPEED_SUPER:
+       case USB_SPEED_UNKNOWN:
+       case USB_SPEED_WIRELESS:
+               /* Should never happen because only LS/FS/HS endpoints will get
+                * added to the endpoint list.
+                */
+               return;
+       }
+       if (tt_info)
+               tt_info->active_eps -= 1;
+       list_del_init(&virt_ep->bw_endpoint_list);
+}
+
+static void xhci_add_ep_to_interval_table(struct xhci_hcd *xhci,
+               struct xhci_bw_info *ep_bw,
+               struct xhci_interval_bw_table *bw_table,
+               struct usb_device *udev,
+               struct xhci_virt_ep *virt_ep,
+               struct xhci_tt_bw_info *tt_info)
+{
+       struct xhci_interval_bw *interval_bw;
+       struct xhci_virt_ep *smaller_ep;
+       int normalized_interval;
+
+       if (xhci_is_async_ep(ep_bw->type))
+               return;
+
+       if (udev->speed == USB_SPEED_SUPER) {
+               if (xhci_is_sync_in_ep(ep_bw->type))
+                       xhci->devs[udev->slot_id]->bw_table->ss_bw_in +=
+                               xhci_get_ss_bw_consumed(ep_bw);
+               else
+                       xhci->devs[udev->slot_id]->bw_table->ss_bw_out +=
+                               xhci_get_ss_bw_consumed(ep_bw);
+               return;
+       }
+
+       /* For LS/FS devices, we need to translate the interval expressed in
+        * microframes to frames.
+        */
+       if (udev->speed == USB_SPEED_HIGH)
+               normalized_interval = ep_bw->ep_interval;
+       else
+               normalized_interval = ep_bw->ep_interval - 3;
+
+       if (normalized_interval == 0)
+               bw_table->interval0_esit_payload += ep_bw->max_esit_payload;
+       interval_bw = &bw_table->interval_bw[normalized_interval];
+       interval_bw->num_packets += ep_bw->num_packets;
+       switch (udev->speed) {
+       case USB_SPEED_LOW:
+               interval_bw->overhead[LS_OVERHEAD_TYPE] += 1;
+               break;
+       case USB_SPEED_FULL:
+               interval_bw->overhead[FS_OVERHEAD_TYPE] += 1;
+               break;
+       case USB_SPEED_HIGH:
+               interval_bw->overhead[HS_OVERHEAD_TYPE] += 1;
+               break;
+       case USB_SPEED_SUPER:
+       case USB_SPEED_UNKNOWN:
+       case USB_SPEED_WIRELESS:
+               /* Should never happen because only LS/FS/HS endpoints will get
+                * added to the endpoint list.
+                */
+               return;
+       }
+
+       if (tt_info)
+               tt_info->active_eps += 1;
+       /* Insert the endpoint into the list, largest max packet size first. */
+       list_for_each_entry(smaller_ep, &interval_bw->endpoints,
+                       bw_endpoint_list) {
+               if (ep_bw->max_packet_size >=
+                               smaller_ep->bw_info.max_packet_size) {
+                       /* Add the new ep before the smaller endpoint */
+                       list_add_tail(&virt_ep->bw_endpoint_list,
+                                       &smaller_ep->bw_endpoint_list);
+                       return;
+               }
+       }
+       /* Add the new endpoint at the end of the list. */
+       list_add_tail(&virt_ep->bw_endpoint_list,
+                       &interval_bw->endpoints);
+}
+
+void xhci_update_tt_active_eps(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev,
+               int old_active_eps)
+{
+       struct xhci_root_port_bw_info *rh_bw_info;
+       if (!virt_dev->tt_info)
+               return;
+
+       rh_bw_info = &xhci->rh_bw[virt_dev->real_port - 1];
+       if (old_active_eps == 0 &&
+                               virt_dev->tt_info->active_eps != 0) {
+               rh_bw_info->num_active_tts += 1;
+               rh_bw_info->bw_table.bw_used += TT_HS_OVERHEAD;
+       } else if (old_active_eps != 0 &&
+                               virt_dev->tt_info->active_eps == 0) {
+               rh_bw_info->num_active_tts -= 1;
+               rh_bw_info->bw_table.bw_used -= TT_HS_OVERHEAD;
+       }
+}
+
+static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev,
+               struct xhci_container_ctx *in_ctx)
+{
+       struct xhci_bw_info ep_bw_info[31];
+       int i;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       int old_active_eps = 0;
+
+       if (virt_dev->tt_info)
+               old_active_eps = virt_dev->tt_info->active_eps;
+
+       ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < 31; i++) {
+               if (!EP_IS_ADDED(ctrl_ctx, i) && !EP_IS_DROPPED(ctrl_ctx, i))
+                       continue;
+
+               /* Make a copy of the BW info in case we need to revert this */
+               memcpy(&ep_bw_info[i], &virt_dev->eps[i].bw_info,
+                               sizeof(ep_bw_info[i]));
+               /* Drop the endpoint from the interval table if the endpoint is
+                * being dropped or changed.
+                */
+               if (EP_IS_DROPPED(ctrl_ctx, i))
+                       xhci_drop_ep_from_interval_table(xhci,
+                                       &virt_dev->eps[i].bw_info,
+                                       virt_dev->bw_table,
+                                       virt_dev->udev,
+                                       &virt_dev->eps[i],
+                                       virt_dev->tt_info);
+       }
+       /* Overwrite the information stored in the endpoints' bw_info */
+       xhci_update_bw_info(xhci, virt_dev->in_ctx, ctrl_ctx, virt_dev);
+       for (i = 0; i < 31; i++) {
+               /* Add any changed or added endpoints to the interval table */
+               if (EP_IS_ADDED(ctrl_ctx, i))
+                       xhci_add_ep_to_interval_table(xhci,
+                                       &virt_dev->eps[i].bw_info,
+                                       virt_dev->bw_table,
+                                       virt_dev->udev,
+                                       &virt_dev->eps[i],
+                                       virt_dev->tt_info);
+       }
+
+       if (!xhci_check_bw_table(xhci, virt_dev, old_active_eps)) {
+               /* Ok, this fits in the bandwidth we have.
+                * Update the number of active TTs.
+                */
+               xhci_update_tt_active_eps(xhci, virt_dev, old_active_eps);
+               return 0;
+       }
+
+       /* We don't have enough bandwidth for this, revert the stored info. */
+       for (i = 0; i < 31; i++) {
+               if (!EP_IS_ADDED(ctrl_ctx, i) && !EP_IS_DROPPED(ctrl_ctx, i))
+                       continue;
+
+               /* Drop the new copies of any added or changed endpoints from
+                * the interval table.
+                */
+               if (EP_IS_ADDED(ctrl_ctx, i)) {
+                       xhci_drop_ep_from_interval_table(xhci,
+                                       &virt_dev->eps[i].bw_info,
+                                       virt_dev->bw_table,
+                                       virt_dev->udev,
+                                       &virt_dev->eps[i],
+                                       virt_dev->tt_info);
+               }
+               /* Revert the endpoint back to its old information */
+               memcpy(&virt_dev->eps[i].bw_info, &ep_bw_info[i],
+                               sizeof(ep_bw_info[i]));
+               /* Add any changed or dropped endpoints back into the table */
+               if (EP_IS_DROPPED(ctrl_ctx, i))
+                       xhci_add_ep_to_interval_table(xhci,
+                                       &virt_dev->eps[i].bw_info,
+                                       virt_dev->bw_table,
+                                       virt_dev->udev,
+                                       &virt_dev->eps[i],
+                                       virt_dev->tt_info);
+       }
+       return -ENOMEM;
+}
+
+
+/* Issue a configure endpoint command or evaluate context command
+ * and wait for it to finish.
+ */
+static int xhci_configure_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct xhci_command *command,
+               bool ctx_change, bool must_succeed)
+{
+       int ret;
+       unsigned long flags;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_virt_device *virt_dev;
+
+       if (!command)
+               return -EINVAL;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       virt_dev = xhci->devs[udev->slot_id];
+
+       ctrl_ctx = xhci_get_input_control_ctx(command->in_ctx);
+       if (!ctrl_ctx) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return -ENOMEM;
+       }
+
+       if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK) &&
+                       xhci_reserve_host_resources(xhci, ctrl_ctx)) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_warn(xhci, "Not enough host resources, "
+                               "active endpoint contexts = %u\n",
+                               xhci->num_active_eps);
+               return -ENOMEM;
+       }
+       if ((xhci->quirks & XHCI_SW_BW_CHECKING) &&
+           xhci_reserve_bandwidth(xhci, virt_dev, command->in_ctx)) {
+               if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK))
+                       xhci_free_host_resources(xhci, ctrl_ctx);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_warn(xhci, "Not enough bandwidth\n");
+               return -ENOMEM;
+       }
+
+       if (!ctx_change)
+               ret = xhci_queue_configure_endpoint(xhci, command,
+                               command->in_ctx->dma,
+                               udev->slot_id, must_succeed);
+       else
+               ret = xhci_queue_evaluate_context(xhci, command,
+                               command->in_ctx->dma,
+                               udev->slot_id, must_succeed);
+       if (ret < 0) {
+               if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK))
+                       xhci_free_host_resources(xhci, ctrl_ctx);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg_trace(xhci,  trace_xhci_dbg_context_change,
+                               "FIXME allocate a new ring segment");
+               return -ENOMEM;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Wait for the configure endpoint command to complete */
+       wait_for_completion(command->completion);
+
+       if (!ctx_change)
+               ret = xhci_configure_endpoint_result(xhci, udev,
+                                                    &command->status);
+       else
+               ret = xhci_evaluate_context_result(xhci, udev,
+                                                  &command->status);
+
+       if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               /* If the command failed, remove the reserved resources.
+                * Otherwise, clean up the estimate to include dropped eps.
+                */
+               if (ret)
+                       xhci_free_host_resources(xhci, ctrl_ctx);
+               else
+                       xhci_finish_resource_reservation(xhci, ctrl_ctx);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       }
+       return ret;
+}
+
+static void xhci_check_bw_drop_ep_streams(struct xhci_hcd *xhci,
+       struct xhci_virt_device *vdev, int i)
+{
+       struct xhci_virt_ep *ep = &vdev->eps[i];
+
+       if (ep->ep_state & EP_HAS_STREAMS) {
+               xhci_warn(xhci, "WARN: endpoint 0x%02x has streams on set_interface, freeing streams.\n",
+                               xhci_get_endpoint_address(i));
+               xhci_free_stream_info(xhci, ep->stream_info);
+               ep->stream_info = NULL;
+               ep->ep_state &= ~EP_HAS_STREAMS;
+       }
+}
+
+/* Called after one or more calls to xhci_add_endpoint() or
+ * xhci_drop_endpoint().  If this call fails, the USB core is expected
+ * to call xhci_reset_bandwidth().
+ *
+ * Since we are in the middle of changing either configuration or
+ * installing a new alt setting, the USB core won't allow URBs to be
+ * enqueued for any endpoint on the old config or interface.  Nothing
+ * else should be touching the xhci->devs[slot_id] structure, so we
+ * don't need to take the xhci->lock for manipulating that.
+ */
+int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       int i;
+       int ret = 0;
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *virt_dev;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       struct xhci_command *command;
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
+       if (ret <= 0)
+               return ret;
+       xhci = hcd_to_xhci(hcd);
+       if (xhci->xhc_state & XHCI_STATE_DYING)
+               return -ENODEV;
+
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+       virt_dev = xhci->devs[udev->slot_id];
+
+       command = xhci_alloc_command(xhci, false, true, GFP_KERNEL);
+       if (!command)
+               return -ENOMEM;
+
+       command->in_ctx = virt_dev->in_ctx;
+
+       /* See section 4.6.6 - A0 = 1; A1 = D0 = D1 = 0 */
+       ctrl_ctx = xhci_get_input_control_ctx(command->in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               ret = -ENOMEM;
+               goto command_cleanup;
+       }
+       ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+       ctrl_ctx->add_flags &= cpu_to_le32(~EP0_FLAG);
+       ctrl_ctx->drop_flags &= cpu_to_le32(~(SLOT_FLAG | EP0_FLAG));
+
+       /* Don't issue the command if there's no endpoints to update. */
+       if (ctrl_ctx->add_flags == cpu_to_le32(SLOT_FLAG) &&
+           ctrl_ctx->drop_flags == 0) {
+               ret = 0;
+               goto command_cleanup;
+       }
+       /* Fix up Context Entries field. Minimum value is EP0 == BIT(1). */
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+       for (i = 31; i >= 1; i--) {
+               __le32 le32 = cpu_to_le32(BIT(i));
+
+               if ((virt_dev->eps[i-1].ring && !(ctrl_ctx->drop_flags & le32))
+                   || (ctrl_ctx->add_flags & le32) || i == 1) {
+                       slot_ctx->dev_info &= cpu_to_le32(~LAST_CTX_MASK);
+                       slot_ctx->dev_info |= cpu_to_le32(LAST_CTX(i));
+                       break;
+               }
+       }
+       xhci_dbg(xhci, "New Input Control Context:\n");
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx,
+                    LAST_CTX_TO_EP_NUM(le32_to_cpu(slot_ctx->dev_info)));
+
+       ret = xhci_configure_endpoint(xhci, udev, command,
+                       false, false);
+       if (ret)
+               /* Callee should call reset_bandwidth() */
+               goto command_cleanup;
+
+       xhci_dbg(xhci, "Output context after successful config ep cmd:\n");
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx,
+                    LAST_CTX_TO_EP_NUM(le32_to_cpu(slot_ctx->dev_info)));
+
+       /* Free any rings that were dropped, but not changed. */
+       for (i = 1; i < 31; ++i) {
+               if ((le32_to_cpu(ctrl_ctx->drop_flags) & (1 << (i + 1))) &&
+                   !(le32_to_cpu(ctrl_ctx->add_flags) & (1 << (i + 1)))) {
+                       xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i);
+                       xhci_check_bw_drop_ep_streams(xhci, virt_dev, i);
+               }
+       }
+       xhci_zero_in_ctx(xhci, virt_dev);
+       /*
+        * Install any rings for completely new endpoints or changed endpoints,
+        * and free or cache any old rings from changed endpoints.
+        */
+       for (i = 1; i < 31; ++i) {
+               if (!virt_dev->eps[i].new_ring)
+                       continue;
+               /* Only cache or free the old ring if it exists.
+                * It may not if this is the first add of an endpoint.
+                */
+               if (virt_dev->eps[i].ring) {
+                       xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i);
+               }
+               xhci_check_bw_drop_ep_streams(xhci, virt_dev, i);
+               virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;
+               virt_dev->eps[i].new_ring = NULL;
+       }
+command_cleanup:
+       kfree(command->completion);
+       kfree(command);
+
+       return ret;
+}
+
+void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *virt_dev;
+       int i, ret;
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
+       if (ret <= 0)
+               return;
+       xhci = hcd_to_xhci(hcd);
+
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+       virt_dev = xhci->devs[udev->slot_id];
+       /* Free any rings allocated for added endpoints */
+       for (i = 0; i < 31; ++i) {
+               if (virt_dev->eps[i].new_ring) {
+                       xhci_ring_free(xhci, virt_dev->eps[i].new_ring);
+                       virt_dev->eps[i].new_ring = NULL;
+               }
+       }
+       xhci_zero_in_ctx(xhci, virt_dev);
+}
+
+static void xhci_setup_input_ctx_for_config_ep(struct xhci_hcd *xhci,
+               struct xhci_container_ctx *in_ctx,
+               struct xhci_container_ctx *out_ctx,
+               struct xhci_input_control_ctx *ctrl_ctx,
+               u32 add_flags, u32 drop_flags)
+{
+       ctrl_ctx->add_flags = cpu_to_le32(add_flags);
+       ctrl_ctx->drop_flags = cpu_to_le32(drop_flags);
+       xhci_slot_copy(xhci, in_ctx, out_ctx);
+       ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+
+       xhci_dbg(xhci, "Input Context:\n");
+       xhci_dbg_ctx(xhci, in_ctx, xhci_last_valid_endpoint(add_flags));
+}
+
+static void xhci_setup_input_ctx_for_quirk(struct xhci_hcd *xhci,
+               unsigned int slot_id, unsigned int ep_index,
+               struct xhci_dequeue_state *deq_state)
+{
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_container_ctx *in_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       u32 added_ctxs;
+       dma_addr_t addr;
+
+       in_ctx = xhci->devs[slot_id]->in_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return;
+       }
+
+       xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
+                       xhci->devs[slot_id]->out_ctx, ep_index);
+       ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
+       addr = xhci_trb_virt_to_dma(deq_state->new_deq_seg,
+                       deq_state->new_deq_ptr);
+       if (addr == 0) {
+               xhci_warn(xhci, "WARN Cannot submit config ep after "
+                               "reset ep command\n");
+               xhci_warn(xhci, "WARN deq seg = %p, deq ptr = %p\n",
+                               deq_state->new_deq_seg,
+                               deq_state->new_deq_ptr);
+               return;
+       }
+       ep_ctx->deq = cpu_to_le64(addr | deq_state->new_cycle_state);
+
+       added_ctxs = xhci_get_endpoint_flag_from_index(ep_index);
+       xhci_setup_input_ctx_for_config_ep(xhci, xhci->devs[slot_id]->in_ctx,
+                       xhci->devs[slot_id]->out_ctx, ctrl_ctx,
+                       added_ctxs, added_ctxs);
+}
+
+void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
+                       unsigned int ep_index, struct xhci_td *td)
+{
+       struct xhci_dequeue_state deq_state;
+       struct xhci_virt_ep *ep;
+       struct usb_device *udev = td->urb->dev;
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_reset_ep,
+                       "Cleaning up stalled endpoint ring");
+       ep = &xhci->devs[udev->slot_id]->eps[ep_index];
+       /* We need to move the HW's dequeue pointer past this TD,
+        * or it will attempt to resend it on the next doorbell ring.
+        */
+       xhci_find_new_dequeue_state(xhci, udev->slot_id,
+                       ep_index, ep->stopped_stream, td, &deq_state);
+
+       if (!deq_state.new_deq_ptr || !deq_state.new_deq_seg)
+               return;
+
+       /* HW with the reset endpoint quirk will use the saved dequeue state to
+        * issue a configure endpoint command later.
+        */
+       if (!(xhci->quirks & XHCI_RESET_EP_QUIRK)) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_reset_ep,
+                               "Queueing new dequeue state");
+               xhci_queue_new_dequeue_state(xhci, udev->slot_id,
+                               ep_index, ep->stopped_stream, &deq_state);
+       } else {
+               /* Better hope no one uses the input context between now and the
+                * reset endpoint completion!
+                * XXX: No idea how this hardware will react when stream rings
+                * are enabled.
+                */
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Setting up input context for "
+                               "configure endpoint command");
+               xhci_setup_input_ctx_for_quirk(xhci, udev->slot_id,
+                               ep_index, &deq_state);
+       }
+}
+
+/* Called when clearing halted device. The core should have sent the control
+ * message to clear the device halt condition. The host side of the halt should
+ * already be cleared with a reset endpoint command issued when the STALL tx
+ * event was received.
+ *
+ * Context: in_interrupt
+ */
+
+void xhci_endpoint_reset(struct usb_hcd *hcd,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+
+       xhci = hcd_to_xhci(hcd);
+
+       /*
+        * We might need to implement the config ep cmd in xhci 4.8.1 note:
+        * The Reset Endpoint Command may only be issued to endpoints in the
+        * Halted state. If software wishes reset the Data Toggle or Sequence
+        * Number of an endpoint that isn't in the Halted state, then software
+        * may issue a Configure Endpoint Command with the Drop and Add bits set
+        * for the target endpoint. that is in the Stopped state.
+        */
+
+       /* For now just print debug to follow the situation */
+       xhci_dbg(xhci, "Endpoint 0x%x ep reset callback called\n",
+                ep->desc.bEndpointAddress);
+}
+
+static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev, struct usb_host_endpoint *ep,
+               unsigned int slot_id)
+{
+       int ret;
+       unsigned int ep_index;
+       unsigned int ep_state;
+
+       if (!ep)
+               return -EINVAL;
+       ret = xhci_check_args(xhci_to_hcd(xhci), udev, ep, 1, true, __func__);
+       if (ret <= 0)
+               return -EINVAL;
+       if (usb_ss_max_streams(&ep->ss_ep_comp) == 0) {
+               xhci_warn(xhci, "WARN: SuperSpeed Endpoint Companion"
+                               " descriptor for ep 0x%x does not support streams\n",
+                               ep->desc.bEndpointAddress);
+               return -EINVAL;
+       }
+
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
+       if (ep_state & EP_HAS_STREAMS ||
+                       ep_state & EP_GETTING_STREAMS) {
+               xhci_warn(xhci, "WARN: SuperSpeed bulk endpoint 0x%x "
+                               "already has streams set up.\n",
+                               ep->desc.bEndpointAddress);
+               xhci_warn(xhci, "Send email to xHCI maintainer and ask for "
+                               "dynamic stream context array reallocation.\n");
+               return -EINVAL;
+       }
+       if (!list_empty(&xhci->devs[slot_id]->eps[ep_index].ring->td_list)) {
+               xhci_warn(xhci, "Cannot setup streams for SuperSpeed bulk "
+                               "endpoint 0x%x; URBs are pending.\n",
+                               ep->desc.bEndpointAddress);
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static void xhci_calculate_streams_entries(struct xhci_hcd *xhci,
+               unsigned int *num_streams, unsigned int *num_stream_ctxs)
+{
+       unsigned int max_streams;
+
+       /* The stream context array size must be a power of two */
+       *num_stream_ctxs = roundup_pow_of_two(*num_streams);
+       /*
+        * Find out how many primary stream array entries the host controller
+        * supports.  Later we may use secondary stream arrays (similar to 2nd
+        * level page entries), but that's an optional feature for xHCI host
+        * controllers. xHCs must support at least 4 stream IDs.
+        */
+       max_streams = HCC_MAX_PSA(xhci->hcc_params);
+       if (*num_stream_ctxs > max_streams) {
+               xhci_dbg(xhci, "xHCI HW only supports %u stream ctx entries.\n",
+                               max_streams);
+               *num_stream_ctxs = max_streams;
+               *num_streams = max_streams;
+       }
+}
+
+/* Returns an error code if one of the endpoint already has streams.
+ * This does not change any data structures, it only checks and gathers
+ * information.
+ */
+static int xhci_calculate_streams_and_bitmask(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_host_endpoint **eps, unsigned int num_eps,
+               unsigned int *num_streams, u32 *changed_ep_bitmask)
+{
+       unsigned int max_streams;
+       unsigned int endpoint_flag;
+       int i;
+       int ret;
+
+       for (i = 0; i < num_eps; i++) {
+               ret = xhci_check_streams_endpoint(xhci, udev,
+                               eps[i], udev->slot_id);
+               if (ret < 0)
+                       return ret;
+
+               max_streams = usb_ss_max_streams(&eps[i]->ss_ep_comp);
+               if (max_streams < (*num_streams - 1)) {
+                       xhci_dbg(xhci, "Ep 0x%x only supports %u stream IDs.\n",
+                                       eps[i]->desc.bEndpointAddress,
+                                       max_streams);
+                       *num_streams = max_streams+1;
+               }
+
+               endpoint_flag = xhci_get_endpoint_flag(&eps[i]->desc);
+               if (*changed_ep_bitmask & endpoint_flag)
+                       return -EINVAL;
+               *changed_ep_bitmask |= endpoint_flag;
+       }
+       return 0;
+}
+
+static u32 xhci_calculate_no_streams_bitmask(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_host_endpoint **eps, unsigned int num_eps)
+{
+       u32 changed_ep_bitmask = 0;
+       unsigned int slot_id;
+       unsigned int ep_index;
+       unsigned int ep_state;
+       int i;
+
+       slot_id = udev->slot_id;
+       if (!xhci->devs[slot_id])
+               return 0;
+
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
+               /* Are streams already being freed for the endpoint? */
+               if (ep_state & EP_GETTING_NO_STREAMS) {
+                       xhci_warn(xhci, "WARN Can't disable streams for "
+                                       "endpoint 0x%x, "
+                                       "streams are being disabled already\n",
+                                       eps[i]->desc.bEndpointAddress);
+                       return 0;
+               }
+               /* Are there actually any streams to free? */
+               if (!(ep_state & EP_HAS_STREAMS) &&
+                               !(ep_state & EP_GETTING_STREAMS)) {
+                       xhci_warn(xhci, "WARN Can't disable streams for "
+                                       "endpoint 0x%x, "
+                                       "streams are already disabled!\n",
+                                       eps[i]->desc.bEndpointAddress);
+                       xhci_warn(xhci, "WARN xhci_free_streams() called "
+                                       "with non-streams endpoint\n");
+                       return 0;
+               }
+               changed_ep_bitmask |= xhci_get_endpoint_flag(&eps[i]->desc);
+       }
+       return changed_ep_bitmask;
+}
+
+/*
+ * The USB device drivers use this function (though the HCD interface in USB
+ * core) to prepare a set of bulk endpoints to use streams.  Streams are used to
+ * coordinate mass storage command queueing across multiple endpoints (basically
+ * a stream ID == a task ID).
+ *
+ * Setting up streams involves allocating the same size stream context array
+ * for each endpoint and issuing a configure endpoint command for all endpoints.
+ *
+ * Don't allow the call to succeed if one endpoint only supports one stream
+ * (which means it doesn't support streams at all).
+ *
+ * Drivers may get less stream IDs than they asked for, if the host controller
+ * hardware or endpoints claim they can't support the number of requested
+ * stream IDs.
+ */
+int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint **eps, unsigned int num_eps,
+               unsigned int num_streams, gfp_t mem_flags)
+{
+       int i, ret;
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *vdev;
+       struct xhci_command *config_cmd;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       unsigned int ep_index;
+       unsigned int num_stream_ctxs;
+       unsigned long flags;
+       u32 changed_ep_bitmask = 0;
+
+       if (!eps)
+               return -EINVAL;
+
+       /* Add one to the number of streams requested to account for
+        * stream 0 that is reserved for xHCI usage.
+        */
+       num_streams += 1;
+       xhci = hcd_to_xhci(hcd);
+       xhci_dbg(xhci, "Driver wants %u stream IDs (including stream 0).\n",
+                       num_streams);
+
+       /* MaxPSASize value 0 (2 streams) means streams are not supported */
+       if ((xhci->quirks & XHCI_BROKEN_STREAMS) ||
+                       HCC_MAX_PSA(xhci->hcc_params) < 4) {
+               xhci_dbg(xhci, "xHCI controller does not support streams.\n");
+               return -ENOSYS;
+       }
+
+       config_cmd = xhci_alloc_command(xhci, true, true, mem_flags);
+       if (!config_cmd) {
+               xhci_dbg(xhci, "Could not allocate xHCI command structure.\n");
+               return -ENOMEM;
+       }
+       ctrl_ctx = xhci_get_input_control_ctx(config_cmd->in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               xhci_free_command(xhci, config_cmd);
+               return -ENOMEM;
+       }
+
+       /* Check to make sure all endpoints are not already configured for
+        * streams.  While we're at it, find the maximum number of streams that
+        * all the endpoints will support and check for duplicate endpoints.
+        */
+       spin_lock_irqsave(&xhci->lock, flags);
+       ret = xhci_calculate_streams_and_bitmask(xhci, udev, eps,
+                       num_eps, &num_streams, &changed_ep_bitmask);
+       if (ret < 0) {
+               xhci_free_command(xhci, config_cmd);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return ret;
+       }
+       if (num_streams <= 1) {
+               xhci_warn(xhci, "WARN: endpoints can't handle "
+                               "more than one stream.\n");
+               xhci_free_command(xhci, config_cmd);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return -EINVAL;
+       }
+       vdev = xhci->devs[udev->slot_id];
+       /* Mark each endpoint as being in transition, so
+        * xhci_urb_enqueue() will reject all URBs.
+        */
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               vdev->eps[ep_index].ep_state |= EP_GETTING_STREAMS;
+       }
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Setup internal data structures and allocate HW data structures for
+        * streams (but don't install the HW structures in the input context
+        * until we're sure all memory allocation succeeded).
+        */
+       xhci_calculate_streams_entries(xhci, &num_streams, &num_stream_ctxs);
+       xhci_dbg(xhci, "Need %u stream ctx entries for %u stream IDs.\n",
+                       num_stream_ctxs, num_streams);
+
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               vdev->eps[ep_index].stream_info = xhci_alloc_stream_info(xhci,
+                               num_stream_ctxs,
+                               num_streams, mem_flags);
+               if (!vdev->eps[ep_index].stream_info)
+                       goto cleanup;
+               /* Set maxPstreams in endpoint context and update deq ptr to
+                * point to stream context array. FIXME
+                */
+       }
+
+       /* Set up the input context for a configure endpoint command. */
+       for (i = 0; i < num_eps; i++) {
+               struct xhci_ep_ctx *ep_ctx;
+
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               ep_ctx = xhci_get_ep_ctx(xhci, config_cmd->in_ctx, ep_index);
+
+               xhci_endpoint_copy(xhci, config_cmd->in_ctx,
+                               vdev->out_ctx, ep_index);
+               xhci_setup_streams_ep_input_ctx(xhci, ep_ctx,
+                               vdev->eps[ep_index].stream_info);
+       }
+       /* Tell the HW to drop its old copy of the endpoint context info
+        * and add the updated copy from the input context.
+        */
+       xhci_setup_input_ctx_for_config_ep(xhci, config_cmd->in_ctx,
+                       vdev->out_ctx, ctrl_ctx,
+                       changed_ep_bitmask, changed_ep_bitmask);
+
+       /* Issue and wait for the configure endpoint command */
+       ret = xhci_configure_endpoint(xhci, udev, config_cmd,
+                       false, false);
+
+       /* xHC rejected the configure endpoint command for some reason, so we
+        * leave the old ring intact and free our internal streams data
+        * structure.
+        */
+       if (ret < 0)
+               goto cleanup;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               vdev->eps[ep_index].ep_state &= ~EP_GETTING_STREAMS;
+               xhci_dbg(xhci, "Slot %u ep ctx %u now has streams.\n",
+                        udev->slot_id, ep_index);
+               vdev->eps[ep_index].ep_state |= EP_HAS_STREAMS;
+       }
+       xhci_free_command(xhci, config_cmd);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Subtract 1 for stream 0, which drivers can't use */
+       return num_streams - 1;
+
+cleanup:
+       /* If it didn't work, free the streams! */
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               xhci_free_stream_info(xhci, vdev->eps[ep_index].stream_info);
+               vdev->eps[ep_index].stream_info = NULL;
+               /* FIXME Unset maxPstreams in endpoint context and
+                * update deq ptr to point to normal string ring.
+                */
+               vdev->eps[ep_index].ep_state &= ~EP_GETTING_STREAMS;
+               vdev->eps[ep_index].ep_state &= ~EP_HAS_STREAMS;
+               xhci_endpoint_zero(xhci, vdev, eps[i]);
+       }
+       xhci_free_command(xhci, config_cmd);
+       return -ENOMEM;
+}
+
+/* Transition the endpoint from using streams to being a "normal" endpoint
+ * without streams.
+ *
+ * Modify the endpoint context state, submit a configure endpoint command,
+ * and free all endpoint rings for streams if that completes successfully.
+ */
+int xhci_free_streams(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint **eps, unsigned int num_eps,
+               gfp_t mem_flags)
+{
+       int i, ret;
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *vdev;
+       struct xhci_command *command;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       unsigned int ep_index;
+       unsigned long flags;
+       u32 changed_ep_bitmask;
+
+       xhci = hcd_to_xhci(hcd);
+       vdev = xhci->devs[udev->slot_id];
+
+       /* Set up a configure endpoint command to remove the streams rings */
+       spin_lock_irqsave(&xhci->lock, flags);
+       changed_ep_bitmask = xhci_calculate_no_streams_bitmask(xhci,
+                       udev, eps, num_eps);
+       if (changed_ep_bitmask == 0) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return -EINVAL;
+       }
+
+       /* Use the xhci_command structure from the first endpoint.  We may have
+        * allocated too many, but the driver may call xhci_free_streams() for
+        * each endpoint it grouped into one call to xhci_alloc_streams().
+        */
+       ep_index = xhci_get_endpoint_index(&eps[0]->desc);
+       command = vdev->eps[ep_index].stream_info->free_streams_command;
+       ctrl_ctx = xhci_get_input_control_ctx(command->in_ctx);
+       if (!ctrl_ctx) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return -EINVAL;
+       }
+
+       for (i = 0; i < num_eps; i++) {
+               struct xhci_ep_ctx *ep_ctx;
+
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               ep_ctx = xhci_get_ep_ctx(xhci, command->in_ctx, ep_index);
+               xhci->devs[udev->slot_id]->eps[ep_index].ep_state |=
+                       EP_GETTING_NO_STREAMS;
+
+               xhci_endpoint_copy(xhci, command->in_ctx,
+                               vdev->out_ctx, ep_index);
+               xhci_setup_no_streams_ep_input_ctx(ep_ctx,
+                               &vdev->eps[ep_index]);
+       }
+       xhci_setup_input_ctx_for_config_ep(xhci, command->in_ctx,
+                       vdev->out_ctx, ctrl_ctx,
+                       changed_ep_bitmask, changed_ep_bitmask);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Issue and wait for the configure endpoint command,
+        * which must succeed.
+        */
+       ret = xhci_configure_endpoint(xhci, udev, command,
+                       false, true);
+
+       /* xHC rejected the configure endpoint command for some reason, so we
+        * leave the streams rings intact.
+        */
+       if (ret < 0)
+               return ret;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       for (i = 0; i < num_eps; i++) {
+               ep_index = xhci_get_endpoint_index(&eps[i]->desc);
+               xhci_free_stream_info(xhci, vdev->eps[ep_index].stream_info);
+               vdev->eps[ep_index].stream_info = NULL;
+               /* FIXME Unset maxPstreams in endpoint context and
+                * update deq ptr to point to normal string ring.
+                */
+               vdev->eps[ep_index].ep_state &= ~EP_GETTING_NO_STREAMS;
+               vdev->eps[ep_index].ep_state &= ~EP_HAS_STREAMS;
+       }
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       return 0;
+}
+
+/*
+ * Deletes endpoint resources for endpoints that were active before a Reset
+ * Device command, or a Disable Slot command.  The Reset Device command leaves
+ * the control endpoint intact, whereas the Disable Slot command deletes it.
+ *
+ * Must be called with xhci->lock held.
+ */
+void xhci_free_device_endpoint_resources(struct xhci_hcd *xhci,
+       struct xhci_virt_device *virt_dev, bool drop_control_ep)
+{
+       int i;
+       unsigned int num_dropped_eps = 0;
+       unsigned int drop_flags = 0;
+
+       for (i = (drop_control_ep ? 0 : 1); i < 31; i++) {
+               if (virt_dev->eps[i].ring) {
+                       drop_flags |= 1 << i;
+                       num_dropped_eps++;
+               }
+       }
+       xhci->num_active_eps -= num_dropped_eps;
+       if (num_dropped_eps)
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Dropped %u ep ctxs, flags = 0x%x, "
+                               "%u now active.",
+                               num_dropped_eps, drop_flags,
+                               xhci->num_active_eps);
+}
+
+/*
+ * This submits a Reset Device Command, which will set the device state to 0,
+ * set the device address to 0, and disable all the endpoints except the default
+ * control endpoint.  The USB core should come back and call
+ * xhci_address_device(), and then re-set up the configuration.  If this is
+ * called because of a usb_reset_and_verify_device(), then the old alternate
+ * settings will be re-installed through the normal bandwidth allocation
+ * functions.
+ *
+ * Wait for the Reset Device command to finish.  Remove all structures
+ * associated with the endpoints that were disabled.  Clear the input device
+ * structure?  Cache the rings?  Reset the control endpoint 0 max packet size?
+ *
+ * If the virt_dev to be reset does not exist or does not match the udev,
+ * it means the device is lost, possibly due to the xHC restore error and
+ * re-initialization during S3/S4. In this case, call xhci_alloc_dev() to
+ * re-allocate the device.
+ */
+int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       int ret, i;
+       unsigned long flags;
+       struct xhci_hcd *xhci;
+       unsigned int slot_id;
+       struct xhci_virt_device *virt_dev;
+       struct xhci_command *reset_device_cmd;
+       int last_freed_endpoint;
+       struct xhci_slot_ctx *slot_ctx;
+       int old_active_eps = 0;
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, false, __func__);
+       if (ret <= 0)
+               return ret;
+       xhci = hcd_to_xhci(hcd);
+       slot_id = udev->slot_id;
+       virt_dev = xhci->devs[slot_id];
+       if (!virt_dev) {
+               xhci_dbg(xhci, "The device to be reset with slot ID %u does "
+                               "not exist. Re-allocate the device\n", slot_id);
+               ret = xhci_alloc_dev(hcd, udev);
+               if (ret == 1)
+                       return 0;
+               else
+                       return -EINVAL;
+       }
+
+       if (virt_dev->udev != udev) {
+               /* If the virt_dev and the udev does not match, this virt_dev
+                * may belong to another udev.
+                * Re-allocate the device.
+                */
+               xhci_dbg(xhci, "The device to be reset with slot ID %u does "
+                               "not match the udev. Re-allocate the device\n",
+                               slot_id);
+               ret = xhci_alloc_dev(hcd, udev);
+               if (ret == 1)
+                       return 0;
+               else
+                       return -EINVAL;
+       }
+
+       /* If device is not setup, there is no point in resetting it */
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+       if (GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state)) ==
+                                               SLOT_STATE_DISABLED)
+               return 0;
+
+       xhci_dbg(xhci, "Resetting device with slot ID %u\n", slot_id);
+       /* Allocate the command structure that holds the struct completion.
+        * Assume we're in process context, since the normal device reset
+        * process has to wait for the device anyway.  Storage devices are
+        * reset as part of error handling, so use GFP_NOIO instead of
+        * GFP_KERNEL.
+        */
+       reset_device_cmd = xhci_alloc_command(xhci, false, true, GFP_NOIO);
+       if (!reset_device_cmd) {
+               xhci_dbg(xhci, "Couldn't allocate command structure.\n");
+               return -ENOMEM;
+       }
+
+       /* Attempt to submit the Reset Device command to the command ring */
+       spin_lock_irqsave(&xhci->lock, flags);
+
+       ret = xhci_queue_reset_device(xhci, reset_device_cmd, slot_id);
+       if (ret) {
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               goto command_cleanup;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Wait for the Reset Device command to finish */
+       wait_for_completion(reset_device_cmd->completion);
+
+       /* The Reset Device command can't fail, according to the 0.95/0.96 spec,
+        * unless we tried to reset a slot ID that wasn't enabled,
+        * or the device wasn't in the addressed or configured state.
+        */
+       ret = reset_device_cmd->status;
+       switch (ret) {
+       case COMP_CMD_ABORT:
+       case COMP_CMD_STOP:
+               xhci_warn(xhci, "Timeout waiting for reset device command\n");
+               ret = -ETIME;
+               goto command_cleanup;
+       case COMP_EBADSLT: /* 0.95 completion code for bad slot ID */
+       case COMP_CTX_STATE: /* 0.96 completion code for same thing */
+               xhci_dbg(xhci, "Can't reset device (slot ID %u) in %s state\n",
+                               slot_id,
+                               xhci_get_slot_state(xhci, virt_dev->out_ctx));
+               xhci_dbg(xhci, "Not freeing device rings.\n");
+               /* Don't treat this as an error.  May change my mind later. */
+               ret = 0;
+               goto command_cleanup;
+       case COMP_SUCCESS:
+               xhci_dbg(xhci, "Successful reset device command.\n");
+               break;
+       default:
+               if (xhci_is_vendor_info_code(xhci, ret))
+                       break;
+               xhci_warn(xhci, "Unknown completion code %u for "
+                               "reset device command.\n", ret);
+               ret = -EINVAL;
+               goto command_cleanup;
+       }
+
+       /* Free up host controller endpoint resources */
+       if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               /* Don't delete the default control endpoint resources */
+               xhci_free_device_endpoint_resources(xhci, virt_dev, false);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       }
+
+       /* Everything but endpoint 0 is disabled, so free or cache the rings. */
+       last_freed_endpoint = 1;
+       for (i = 1; i < 31; ++i) {
+               struct xhci_virt_ep *ep = &virt_dev->eps[i];
+
+               if (ep->ep_state & EP_HAS_STREAMS) {
+                       xhci_warn(xhci, "WARN: endpoint 0x%02x has streams on device reset, freeing streams.\n",
+                                       xhci_get_endpoint_address(i));
+                       xhci_free_stream_info(xhci, ep->stream_info);
+                       ep->stream_info = NULL;
+                       ep->ep_state &= ~EP_HAS_STREAMS;
+               }
+
+               if (ep->ring) {
+                       xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i);
+                       last_freed_endpoint = i;
+               }
+               if (!list_empty(&virt_dev->eps[i].bw_endpoint_list))
+                       xhci_drop_ep_from_interval_table(xhci,
+                                       &virt_dev->eps[i].bw_info,
+                                       virt_dev->bw_table,
+                                       udev,
+                                       &virt_dev->eps[i],
+                                       virt_dev->tt_info);
+               xhci_clear_endpoint_bw_info(&virt_dev->eps[i].bw_info);
+       }
+       /* If necessary, update the number of active TTs on this root port */
+       xhci_update_tt_active_eps(xhci, virt_dev, old_active_eps);
+
+       xhci_dbg(xhci, "Output context after successful reset device cmd:\n");
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx, last_freed_endpoint);
+       ret = 0;
+
+command_cleanup:
+       xhci_free_command(xhci, reset_device_cmd);
+       return ret;
+}
+
+/*
+ * At this point, the struct usb_device is about to go away, the device has
+ * disconnected, and all traffic has been stopped and the endpoints have been
+ * disabled.  Free any HC data structures associated with that device.
+ */
+void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_virt_device *virt_dev;
+       unsigned long flags;
+       u32 state;
+       int i, ret;
+       struct xhci_command *command;
+
+       command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
+       if (!command)
+               return;
+
+#ifndef CONFIG_USB_DEFAULT_PERSIST
+       /*
+        * We called pm_runtime_get_noresume when the device was attached.
+        * Decrement the counter here to allow controller to runtime suspend
+        * if no devices remain.
+        */
+       if (xhci->quirks & XHCI_RESET_ON_RESUME)
+               pm_runtime_put_noidle(hcd->self.controller);
+#endif
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
+       /* If the host is halted due to driver unload, we still need to free the
+        * device.
+        */
+       if (ret <= 0 && ret != -ENODEV) {
+               kfree(command);
+               return;
+       }
+
+       virt_dev = xhci->devs[udev->slot_id];
+
+       /* Stop any wayward timer functions (which may grab the lock) */
+       for (i = 0; i < 31; ++i) {
+               virt_dev->eps[i].ep_state &= ~EP_HALT_PENDING;
+               del_timer_sync(&virt_dev->eps[i].stop_cmd_timer);
+       }
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       /* Don't disable the slot if the host controller is dead. */
+       state = readl(&xhci->op_regs->status);
+       if (state == 0xffffffff || (xhci->xhc_state & XHCI_STATE_DYING) ||
+                       (xhci->xhc_state & XHCI_STATE_HALTED)) {
+               xhci_free_virt_device(xhci, udev->slot_id);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               kfree(command);
+               return;
+       }
+
+       if (xhci_queue_slot_control(xhci, command, TRB_DISABLE_SLOT,
+                                   udev->slot_id)) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               return;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /*
+        * Event command completion handler will free any data structures
+        * associated with the slot.  XXX Can free sleep?
+        */
+}
+
+/*
+ * Checks if we have enough host controller resources for the default control
+ * endpoint.
+ *
+ * Must be called with xhci->lock held.
+ */
+static int xhci_reserve_host_control_ep_resources(struct xhci_hcd *xhci)
+{
+       if (xhci->num_active_eps + 1 > xhci->limit_active_eps) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                               "Not enough ep ctxs: "
+                               "%u active, need to add 1, limit is %u.",
+                               xhci->num_active_eps, xhci->limit_active_eps);
+               return -ENOMEM;
+       }
+       xhci->num_active_eps += 1;
+       xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
+                       "Adding 1 ep ctx, %u now active.",
+                       xhci->num_active_eps);
+       return 0;
+}
+
+
+/*
+ * Returns 0 if the xHC ran out of device slots, the Enable Slot command
+ * timed out, or allocating memory failed.  Returns 1 on success.
+ */
+int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       unsigned long flags;
+       int ret, slot_id;
+       struct xhci_command *command;
+
+       command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
+       if (!command)
+               return 0;
+
+       /* xhci->slot_id and xhci->addr_dev are not thread-safe */
+       mutex_lock(&xhci->mutex);
+       spin_lock_irqsave(&xhci->lock, flags);
+       command->completion = &xhci->addr_dev;
+       ret = xhci_queue_slot_control(xhci, command, TRB_ENABLE_SLOT, 0);
+       if (ret) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               mutex_unlock(&xhci->mutex);
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               kfree(command);
+               return 0;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       wait_for_completion(command->completion);
+       slot_id = xhci->slot_id;
+       mutex_unlock(&xhci->mutex);
+
+       if (!slot_id || command->status != COMP_SUCCESS) {
+               xhci_err(xhci, "Error while assigning device slot ID\n");
+               xhci_err(xhci, "Max number of devices this xHCI host supports is %u.\n",
+                               HCS_MAX_SLOTS(
+                                       readl(&xhci->cap_regs->hcs_params1)));
+               kfree(command);
+               return 0;
+       }
+
+       if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               ret = xhci_reserve_host_control_ep_resources(xhci);
+               if (ret) {
+                       spin_unlock_irqrestore(&xhci->lock, flags);
+                       xhci_warn(xhci, "Not enough host resources, "
+                                       "active endpoint contexts = %u\n",
+                                       xhci->num_active_eps);
+                       goto disable_slot;
+               }
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       }
+       /* Use GFP_NOIO, since this function can be called from
+        * xhci_discover_or_reset_device(), which may be called as part of
+        * mass storage driver error handling.
+        */
+       if (!xhci_alloc_virt_device(xhci, slot_id, udev, GFP_NOIO)) {
+               xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
+               goto disable_slot;
+       }
+       udev->slot_id = slot_id;
+
+#ifndef CONFIG_USB_DEFAULT_PERSIST
+       /*
+        * If resetting upon resume, we can't put the controller into runtime
+        * suspend if there is a device attached.
+        */
+       if (xhci->quirks & XHCI_RESET_ON_RESUME)
+               pm_runtime_get_noresume(hcd->self.controller);
+#endif
+
+
+       kfree(command);
+       /* Is this a LS or FS device under a HS hub? */
+       /* Hub or peripherial? */
+       return 1;
+
+disable_slot:
+       /* Disable slot, if we can do it without mem alloc */
+       spin_lock_irqsave(&xhci->lock, flags);
+       command->completion = NULL;
+       command->status = 0;
+       if (!xhci_queue_slot_control(xhci, command, TRB_DISABLE_SLOT,
+                                    udev->slot_id))
+               xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return 0;
+}
+
+/*
+ * Issue an Address Device command and optionally send a corresponding
+ * SetAddress request to the device.
+ * We should be protected by the usb_address0_mutex in hub_wq's hub_port_init,
+ * so we should only issue and wait on one address command at the same time.
+ */
+static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
+                            enum xhci_setup_dev setup)
+{
+       const char *act = setup == SETUP_CONTEXT_ONLY ? "context" : "address";
+       unsigned long flags;
+       struct xhci_virt_device *virt_dev;
+       int ret = 0;
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_slot_ctx *slot_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       u64 temp_64;
+       struct xhci_command *command = NULL;
+
+       mutex_lock(&xhci->mutex);
+
+       if (!udev->slot_id) {
+               xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                               "Bad Slot ID %d", udev->slot_id);
+               ret = -EINVAL;
+               goto out;
+       }
+
+       virt_dev = xhci->devs[udev->slot_id];
+
+       if (WARN_ON(!virt_dev)) {
+               /*
+                * In plug/unplug torture test with an NEC controller,
+                * a zero-dereference was observed once due to virt_dev = 0.
+                * Print useful debug rather than crash if it is observed again!
+                */
+               xhci_warn(xhci, "Virt dev invalid for slot_id 0x%x!\n",
+                       udev->slot_id);
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (setup == SETUP_CONTEXT_ONLY) {
+               slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+               if (GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state)) ==
+                   SLOT_STATE_DEFAULT) {
+                       xhci_dbg(xhci, "Slot already in default state\n");
+                       goto out;
+               }
+       }
+
+       command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
+       if (!command) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       command->in_ctx = virt_dev->in_ctx;
+       command->completion = &xhci->addr_dev;
+
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+       ctrl_ctx = xhci_get_input_control_ctx(virt_dev->in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               ret = -EINVAL;
+               goto out;
+       }
+       /*
+        * If this is the first Set Address since device plug-in or
+        * virt_device realloaction after a resume with an xHCI power loss,
+        * then set up the slot context.
+        */
+       if (!slot_ctx->dev_info)
+               xhci_setup_addressable_virt_dev(xhci, udev);
+       /* Otherwise, update the control endpoint ring enqueue pointer. */
+       else
+               xhci_copy_ep0_dequeue_into_input_ctx(xhci, udev);
+       ctrl_ctx->add_flags = cpu_to_le32(SLOT_FLAG | EP0_FLAG);
+       ctrl_ctx->drop_flags = 0;
+
+       xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
+       trace_xhci_address_ctx(xhci, virt_dev->in_ctx,
+                               le32_to_cpu(slot_ctx->dev_info) >> 27);
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       ret = xhci_queue_address_device(xhci, command, virt_dev->in_ctx->dma,
+                                       udev->slot_id, setup);
+       if (ret) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                               "FIXME: allocate a command ring segment");
+               goto out;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* ctrl tx can take up to 5 sec; XXX: need more time for xHC? */
+       wait_for_completion(command->completion);
+
+       /* FIXME: From section 4.3.4: "Software shall be responsible for timing
+        * the SetAddress() "recovery interval" required by USB and aborting the
+        * command on a timeout.
+        */
+       switch (command->status) {
+       case COMP_CMD_ABORT:
+       case COMP_CMD_STOP:
+               xhci_warn(xhci, "Timeout while waiting for setup device command\n");
+               ret = -ETIME;
+               break;
+       case COMP_CTX_STATE:
+       case COMP_EBADSLT:
+               xhci_err(xhci, "Setup ERROR: setup %s command for slot %d.\n",
+                        act, udev->slot_id);
+               ret = -EINVAL;
+               break;
+       case COMP_TX_ERR:
+               dev_warn(&udev->dev, "Device not responding to setup %s.\n", act);
+               ret = -EPROTO;
+               break;
+       case COMP_DEV_ERR:
+               dev_warn(&udev->dev,
+                        "ERROR: Incompatible device for setup %s command\n", act);
+               ret = -ENODEV;
+               break;
+       case COMP_SUCCESS:
+               xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                              "Successful setup %s command", act);
+               break;
+       default:
+               xhci_err(xhci,
+                        "ERROR: unexpected setup %s command completion code 0x%x.\n",
+                        act, command->status);
+               xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
+               xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
+               trace_xhci_address_ctx(xhci, virt_dev->out_ctx, 1);
+               ret = -EINVAL;
+               break;
+       }
+       if (ret)
+               goto out;
+       temp_64 = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                       "Op regs DCBAA ptr = %#016llx", temp_64);
+       xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+               "Slot ID %d dcbaa entry @%p = %#016llx",
+               udev->slot_id,
+               &xhci->dcbaa->dev_context_ptrs[udev->slot_id],
+               (unsigned long long)
+               le64_to_cpu(xhci->dcbaa->dev_context_ptrs[udev->slot_id]));
+       xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                       "Output Context DMA address = %#08llx",
+                       (unsigned long long)virt_dev->out_ctx->dma);
+       xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
+       trace_xhci_address_ctx(xhci, virt_dev->in_ctx,
+                               le32_to_cpu(slot_ctx->dev_info) >> 27);
+       xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
+       /*
+        * USB core uses address 1 for the roothubs, so we add one to the
+        * address given back to us by the HC.
+        */
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+       trace_xhci_address_ctx(xhci, virt_dev->out_ctx,
+                               le32_to_cpu(slot_ctx->dev_info) >> 27);
+       /* Zero the input context control for later use */
+       ctrl_ctx->add_flags = 0;
+       ctrl_ctx->drop_flags = 0;
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_address,
+                      "Internal device address = %d",
+                      le32_to_cpu(slot_ctx->dev_state) & DEV_ADDR_MASK);
+out:
+       mutex_unlock(&xhci->mutex);
+       kfree(command);
+       return ret;
+}
+
+int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ADDRESS);
+}
+
+int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ONLY);
+}
+
+/*
+ * Transfer the port index into real index in the HW port status
+ * registers. Caculate offset between the port's PORTSC register
+ * and port status base. Divide the number of per port register
+ * to get the real index. The raw port number bases 1.
+ */
+int xhci_find_raw_port_number(struct usb_hcd *hcd, int port1)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       __le32 __iomem *base_addr = &xhci->op_regs->port_status_base;
+       __le32 __iomem *addr;
+       int raw_port;
+
+       if (hcd->speed != HCD_USB3)
+               addr = xhci->usb2_ports[port1 - 1];
+       else
+               addr = xhci->usb3_ports[port1 - 1];
+
+       raw_port = (addr - base_addr)/NUM_PORT_REGS + 1;
+       return raw_port;
+}
+
+/*
+ * Issue an Evaluate Context command to change the Maximum Exit Latency in the
+ * slot context.  If that succeeds, store the new MEL in the xhci_virt_device.
+ */
+static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
+                       struct usb_device *udev, u16 max_exit_latency)
+{
+       struct xhci_virt_device *virt_dev;
+       struct xhci_command *command;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+
+       virt_dev = xhci->devs[udev->slot_id];
+
+       /*
+        * virt_dev might not exists yet if xHC resumed from hibernate (S4) and
+        * xHC was re-initialized. Exit latency will be set later after
+        * hub_port_finish_reset() is done and xhci->devs[] are re-allocated
+        */
+
+       if (!virt_dev || max_exit_latency == virt_dev->current_mel) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return 0;
+       }
+
+       /* Attempt to issue an Evaluate Context command to change the MEL. */
+       command = xhci->lpm_command;
+       ctrl_ctx = xhci_get_input_control_ctx(command->in_ctx);
+       if (!ctrl_ctx) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               return -ENOMEM;
+       }
+
+       xhci_slot_copy(xhci, command->in_ctx, virt_dev->out_ctx);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+       slot_ctx = xhci_get_slot_ctx(xhci, command->in_ctx);
+       slot_ctx->dev_info2 &= cpu_to_le32(~((u32) MAX_EXIT));
+       slot_ctx->dev_info2 |= cpu_to_le32(max_exit_latency);
+       slot_ctx->dev_state = 0;
+
+       xhci_dbg_trace(xhci, trace_xhci_dbg_context_change,
+                       "Set up evaluate context for LPM MEL change.");
+       xhci_dbg(xhci, "Slot %u Input Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, command->in_ctx, 0);
+
+       /* Issue and wait for the evaluate context command. */
+       ret = xhci_configure_endpoint(xhci, udev, command,
+                       true, true);
+       xhci_dbg(xhci, "Slot %u Output Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx, 0);
+
+       if (!ret) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               virt_dev->current_mel = max_exit_latency;
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       }
+       return ret;
+}
+
+#ifdef CONFIG_PM
+
+/* BESL to HIRD Encoding array for USB2 LPM */
+static int xhci_besl_encoding[16] = {125, 150, 200, 300, 400, 500, 1000, 2000,
+       3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000};
+
+/* Calculate HIRD/BESL for USB2 PORTPMSC*/
+static int xhci_calculate_hird_besl(struct xhci_hcd *xhci,
+                                       struct usb_device *udev)
+{
+       int u2del, besl, besl_host;
+       int besl_device = 0;
+       u32 field;
+
+       u2del = HCS_U2_LATENCY(xhci->hcs_params3);
+       field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
+
+       if (field & USB_BESL_SUPPORT) {
+               for (besl_host = 0; besl_host < 16; besl_host++) {
+                       if (xhci_besl_encoding[besl_host] >= u2del)
+                               break;
+               }
+               /* Use baseline BESL value as default */
+               if (field & USB_BESL_BASELINE_VALID)
+                       besl_device = USB_GET_BESL_BASELINE(field);
+               else if (field & USB_BESL_DEEP_VALID)
+                       besl_device = USB_GET_BESL_DEEP(field);
+       } else {
+               if (u2del <= 50)
+                       besl_host = 0;
+               else
+                       besl_host = (u2del - 51) / 75 + 1;
+       }
+
+       besl = besl_host + besl_device;
+       if (besl > 15)
+               besl = 15;
+
+       return besl;
+}
+
+/* Calculate BESLD, L1 timeout and HIRDM for USB2 PORTHLPMC */
+static int xhci_calculate_usb2_hw_lpm_params(struct usb_device *udev)
+{
+       u32 field;
+       int l1;
+       int besld = 0;
+       int hirdm = 0;
+
+       field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
+
+       /* xHCI l1 is set in steps of 256us, xHCI 1.0 section 5.4.11.2 */
+       l1 = udev->l1_params.timeout / 256;
+
+       /* device has preferred BESLD */
+       if (field & USB_BESL_DEEP_VALID) {
+               besld = USB_GET_BESL_DEEP(field);
+               hirdm = 1;
+       }
+
+       return PORT_BESLD(besld) | PORT_L1_TIMEOUT(l1) | PORT_HIRDM(hirdm);
+}
+
+int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
+                       struct usb_device *udev, int enable)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       __le32 __iomem  **port_array;
+       __le32 __iomem  *pm_addr, *hlpm_addr;
+       u32             pm_val, hlpm_val, field;
+       unsigned int    port_num;
+       unsigned long   flags;
+       int             hird, exit_latency;
+       int             ret;
+
+       if (hcd->speed == HCD_USB3 || !xhci->hw_lpm_support ||
+                       !udev->lpm_capable)
+               return -EPERM;
+
+       if (!udev->parent || udev->parent->parent ||
+                       udev->descriptor.bDeviceClass == USB_CLASS_HUB)
+               return -EPERM;
+
+       if (udev->usb2_hw_lpm_capable != 1)
+               return -EPERM;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+
+       port_array = xhci->usb2_ports;
+       port_num = udev->portnum - 1;
+       pm_addr = port_array[port_num] + PORTPMSC;
+       pm_val = readl(pm_addr);
+       hlpm_addr = port_array[port_num] + PORTHLPMC;
+       field = le32_to_cpu(udev->bos->ext_cap->bmAttributes);
+
+       xhci_dbg(xhci, "%s port %d USB2 hardware LPM\n",
+                       enable ? "enable" : "disable", port_num + 1);
+
+       if (enable) {
+               /* Host supports BESL timeout instead of HIRD */
+               if (udev->usb2_hw_lpm_besl_capable) {
+                       /* if device doesn't have a preferred BESL value use a
+                        * default one which works with mixed HIRD and BESL
+                        * systems. See XHCI_DEFAULT_BESL definition in xhci.h
+                        */
+                       if ((field & USB_BESL_SUPPORT) &&
+                           (field & USB_BESL_BASELINE_VALID))
+                               hird = USB_GET_BESL_BASELINE(field);
+                       else
+                               hird = udev->l1_params.besl;
+
+                       exit_latency = xhci_besl_encoding[hird];
+                       spin_unlock_irqrestore(&xhci->lock, flags);
+
+                       /* USB 3.0 code dedicate one xhci->lpm_command->in_ctx
+                        * input context for link powermanagement evaluate
+                        * context commands. It is protected by hcd->bandwidth
+                        * mutex and is shared by all devices. We need to set
+                        * the max ext latency in USB 2 BESL LPM as well, so
+                        * use the same mutex and xhci_change_max_exit_latency()
+                        */
+                       mutex_lock(hcd->bandwidth_mutex);
+                       ret = xhci_change_max_exit_latency(xhci, udev,
+                                                          exit_latency);
+                       mutex_unlock(hcd->bandwidth_mutex);
+
+                       if (ret < 0)
+                               return ret;
+                       spin_lock_irqsave(&xhci->lock, flags);
+
+                       hlpm_val = xhci_calculate_usb2_hw_lpm_params(udev);
+                       writel(hlpm_val, hlpm_addr);
+                       /* flush write */
+                       readl(hlpm_addr);
+               } else {
+                       hird = xhci_calculate_hird_besl(xhci, udev);
+               }
+
+               pm_val &= ~PORT_HIRD_MASK;
+               pm_val |= PORT_HIRD(hird) | PORT_RWE | PORT_L1DS(udev->slot_id);
+               writel(pm_val, pm_addr);
+               pm_val = readl(pm_addr);
+               pm_val |= PORT_HLE;
+               writel(pm_val, pm_addr);
+               /* flush write */
+               readl(pm_addr);
+       } else {
+               pm_val &= ~(PORT_HLE | PORT_RWE | PORT_HIRD_MASK | PORT_L1DS_MASK);
+               writel(pm_val, pm_addr);
+               /* flush write */
+               readl(pm_addr);
+               if (udev->usb2_hw_lpm_besl_capable) {
+                       spin_unlock_irqrestore(&xhci->lock, flags);
+                       mutex_lock(hcd->bandwidth_mutex);
+                       xhci_change_max_exit_latency(xhci, udev, 0);
+                       mutex_unlock(hcd->bandwidth_mutex);
+                       return 0;
+               }
+       }
+
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return 0;
+}
+
+/* check if a usb2 port supports a given extened capability protocol
+ * only USB2 ports extended protocol capability values are cached.
+ * Return 1 if capability is supported
+ */
+static int xhci_check_usb2_port_capability(struct xhci_hcd *xhci, int port,
+                                          unsigned capability)
+{
+       u32 port_offset, port_count;
+       int i;
+
+       for (i = 0; i < xhci->num_ext_caps; i++) {
+               if (xhci->ext_caps[i] & capability) {
+                       /* port offsets starts at 1 */
+                       port_offset = XHCI_EXT_PORT_OFF(xhci->ext_caps[i]) - 1;
+                       port_count = XHCI_EXT_PORT_COUNT(xhci->ext_caps[i]);
+                       if (port >= port_offset &&
+                           port < port_offset + port_count)
+                               return 1;
+               }
+       }
+       return 0;
+}
+
+int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       int             portnum = udev->portnum - 1;
+
+       if (hcd->speed == HCD_USB3 || !xhci->sw_lpm_support ||
+                       !udev->lpm_capable)
+               return 0;
+
+       /* we only support lpm for non-hub device connected to root hub yet */
+       if (!udev->parent || udev->parent->parent ||
+                       udev->descriptor.bDeviceClass == USB_CLASS_HUB)
+               return 0;
+
+       if (xhci->hw_lpm_support == 1 &&
+                       xhci_check_usb2_port_capability(
+                               xhci, portnum, XHCI_HLC)) {
+               udev->usb2_hw_lpm_capable = 1;
+               udev->l1_params.timeout = XHCI_L1_TIMEOUT;
+               udev->l1_params.besl = XHCI_DEFAULT_BESL;
+               if (xhci_check_usb2_port_capability(xhci, portnum,
+                                       XHCI_BLC))
+                       udev->usb2_hw_lpm_besl_capable = 1;
+       }
+
+       return 0;
+}
+
+/*---------------------- USB 3.0 Link PM functions ------------------------*/
+
+/* Service interval in nanoseconds = 2^(bInterval - 1) * 125us * 1000ns / 1us */
+static unsigned long long xhci_service_interval_to_ns(
+               struct usb_endpoint_descriptor *desc)
+{
+       return (1ULL << (desc->bInterval - 1)) * 125 * 1000;
+}
+
+static u16 xhci_get_timeout_no_hub_lpm(struct usb_device *udev,
+               enum usb3_link_state state)
+{
+       unsigned long long sel;
+       unsigned long long pel;
+       unsigned int max_sel_pel;
+       char *state_name;
+
+       switch (state) {
+       case USB3_LPM_U1:
+               /* Convert SEL and PEL stored in nanoseconds to microseconds */
+               sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
+               pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
+               max_sel_pel = USB3_LPM_MAX_U1_SEL_PEL;
+               state_name = "U1";
+               break;
+       case USB3_LPM_U2:
+               sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
+               pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
+               max_sel_pel = USB3_LPM_MAX_U2_SEL_PEL;
+               state_name = "U2";
+               break;
+       default:
+               dev_warn(&udev->dev, "%s: Can't get timeout for non-U1 or U2 state.\n",
+                               __func__);
+               return USB3_LPM_DISABLED;
+       }
+
+       if (sel <= max_sel_pel && pel <= max_sel_pel)
+               return USB3_LPM_DEVICE_INITIATED;
+
+       if (sel > max_sel_pel)
+               dev_dbg(&udev->dev, "Device-initiated %s disabled "
+                               "due to long SEL %llu ms\n",
+                               state_name, sel);
+       else
+               dev_dbg(&udev->dev, "Device-initiated %s disabled "
+                               "due to long PEL %llu ms\n",
+                               state_name, pel);
+       return USB3_LPM_DISABLED;
+}
+
+/* The U1 timeout should be the maximum of the following values:
+ *  - For control endpoints, U1 system exit latency (SEL) * 3
+ *  - For bulk endpoints, U1 SEL * 5
+ *  - For interrupt endpoints:
+ *    - Notification EPs, U1 SEL * 3
+ *    - Periodic EPs, max(105% of bInterval, U1 SEL * 2)
+ *  - For isochronous endpoints, max(105% of bInterval, U1 SEL * 2)
+ */
+static unsigned long long xhci_calculate_intel_u1_timeout(
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc)
+{
+       unsigned long long timeout_ns;
+       int ep_type;
+       int intr_type;
+
+       ep_type = usb_endpoint_type(desc);
+       switch (ep_type) {
+       case USB_ENDPOINT_XFER_CONTROL:
+               timeout_ns = udev->u1_params.sel * 3;
+               break;
+       case USB_ENDPOINT_XFER_BULK:
+               timeout_ns = udev->u1_params.sel * 5;
+               break;
+       case USB_ENDPOINT_XFER_INT:
+               intr_type = usb_endpoint_interrupt_type(desc);
+               if (intr_type == USB_ENDPOINT_INTR_NOTIFICATION) {
+                       timeout_ns = udev->u1_params.sel * 3;
+                       break;
+               }
+               /* Otherwise the calculation is the same as isoc eps */
+       case USB_ENDPOINT_XFER_ISOC:
+               timeout_ns = xhci_service_interval_to_ns(desc);
+               timeout_ns = DIV_ROUND_UP_ULL(timeout_ns * 105, 100);
+               if (timeout_ns < udev->u1_params.sel * 2)
+                       timeout_ns = udev->u1_params.sel * 2;
+               break;
+       default:
+               return 0;
+       }
+
+       return timeout_ns;
+}
+
+/* Returns the hub-encoded U1 timeout value. */
+static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc)
+{
+       unsigned long long timeout_ns;
+
+       if (xhci->quirks & XHCI_INTEL_HOST)
+               timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc);
+       else
+               timeout_ns = udev->u1_params.sel;
+
+       /* The U1 timeout is encoded in 1us intervals.
+        * Don't return a timeout of zero, because that's USB3_LPM_DISABLED.
+        */
+       if (timeout_ns == USB3_LPM_DISABLED)
+               timeout_ns = 1;
+       else
+               timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 1000);
+
+       /* If the necessary timeout value is bigger than what we can set in the
+        * USB 3.0 hub, we have to disable hub-initiated U1.
+        */
+       if (timeout_ns <= USB3_LPM_U1_MAX_TIMEOUT)
+               return timeout_ns;
+       dev_dbg(&udev->dev, "Hub-initiated U1 disabled "
+                       "due to long timeout %llu ms\n", timeout_ns);
+       return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U1);
+}
+
+/* The U2 timeout should be the maximum of:
+ *  - 10 ms (to avoid the bandwidth impact on the scheduler)
+ *  - largest bInterval of any active periodic endpoint (to avoid going
+ *    into lower power link states between intervals).
+ *  - the U2 Exit Latency of the device
+ */
+static unsigned long long xhci_calculate_intel_u2_timeout(
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc)
+{
+       unsigned long long timeout_ns;
+       unsigned long long u2_del_ns;
+
+       timeout_ns = 10 * 1000 * 1000;
+
+       if ((usb_endpoint_xfer_int(desc) || usb_endpoint_xfer_isoc(desc)) &&
+                       (xhci_service_interval_to_ns(desc) > timeout_ns))
+               timeout_ns = xhci_service_interval_to_ns(desc);
+
+       u2_del_ns = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat) * 1000ULL;
+       if (u2_del_ns > timeout_ns)
+               timeout_ns = u2_del_ns;
+
+       return timeout_ns;
+}
+
+/* Returns the hub-encoded U2 timeout value. */
+static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc)
+{
+       unsigned long long timeout_ns;
+
+       if (xhci->quirks & XHCI_INTEL_HOST)
+               timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc);
+       else
+               timeout_ns = udev->u2_params.sel;
+
+       /* The U2 timeout is encoded in 256us intervals */
+       timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 256 * 1000);
+       /* If the necessary timeout value is bigger than what we can set in the
+        * USB 3.0 hub, we have to disable hub-initiated U2.
+        */
+       if (timeout_ns <= USB3_LPM_U2_MAX_TIMEOUT)
+               return timeout_ns;
+       dev_dbg(&udev->dev, "Hub-initiated U2 disabled "
+                       "due to long timeout %llu ms\n", timeout_ns);
+       return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U2);
+}
+
+static u16 xhci_call_host_update_timeout_for_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc,
+               enum usb3_link_state state,
+               u16 *timeout)
+{
+       if (state == USB3_LPM_U1)
+               return xhci_calculate_u1_timeout(xhci, udev, desc);
+       else if (state == USB3_LPM_U2)
+               return xhci_calculate_u2_timeout(xhci, udev, desc);
+
+       return USB3_LPM_DISABLED;
+}
+
+static int xhci_update_timeout_for_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc,
+               enum usb3_link_state state,
+               u16 *timeout)
+{
+       u16 alt_timeout;
+
+       alt_timeout = xhci_call_host_update_timeout_for_endpoint(xhci, udev,
+               desc, state, timeout);
+
+       /* If we found we can't enable hub-initiated LPM, or
+        * the U1 or U2 exit latency was too high to allow
+        * device-initiated LPM as well, just stop searching.
+        */
+       if (alt_timeout == USB3_LPM_DISABLED ||
+                       alt_timeout == USB3_LPM_DEVICE_INITIATED) {
+               *timeout = alt_timeout;
+               return -E2BIG;
+       }
+       if (alt_timeout > *timeout)
+               *timeout = alt_timeout;
+       return 0;
+}
+
+static int xhci_update_timeout_for_interface(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct usb_host_interface *alt,
+               enum usb3_link_state state,
+               u16 *timeout)
+{
+       int j;
+
+       for (j = 0; j < alt->desc.bNumEndpoints; j++) {
+               if (xhci_update_timeout_for_endpoint(xhci, udev,
+                                       &alt->endpoint[j].desc, state, timeout))
+                       return -E2BIG;
+               continue;
+       }
+       return 0;
+}
+
+static int xhci_check_intel_tier_policy(struct usb_device *udev,
+               enum usb3_link_state state)
+{
+       struct usb_device *parent;
+       unsigned int num_hubs;
+
+       if (state == USB3_LPM_U2)
+               return 0;
+
+       /* Don't enable U1 if the device is on a 2nd tier hub or lower. */
+       for (parent = udev->parent, num_hubs = 0; parent->parent;
+                       parent = parent->parent)
+               num_hubs++;
+
+       if (num_hubs < 2)
+               return 0;
+
+       dev_dbg(&udev->dev, "Disabling U1 link state for device"
+                       " below second-tier hub.\n");
+       dev_dbg(&udev->dev, "Plug device into first-tier hub "
+                       "to decrease power consumption.\n");
+       return -E2BIG;
+}
+
+static int xhci_check_tier_policy(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               enum usb3_link_state state)
+{
+       if (xhci->quirks & XHCI_INTEL_HOST)
+               return xhci_check_intel_tier_policy(udev, state);
+       else
+               return 0;
+}
+
+/* Returns the U1 or U2 timeout that should be enabled.
+ * If the tier check or timeout setting functions return with a non-zero exit
+ * code, that means the timeout value has been finalized and we shouldn't look
+ * at any more endpoints.
+ */
+static u16 xhci_calculate_lpm_timeout(struct usb_hcd *hcd,
+                       struct usb_device *udev, enum usb3_link_state state)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct usb_host_config *config;
+       char *state_name;
+       int i;
+       u16 timeout = USB3_LPM_DISABLED;
+
+       if (state == USB3_LPM_U1)
+               state_name = "U1";
+       else if (state == USB3_LPM_U2)
+               state_name = "U2";
+       else {
+               dev_warn(&udev->dev, "Can't enable unknown link state %i\n",
+                               state);
+               return timeout;
+       }
+
+       if (xhci_check_tier_policy(xhci, udev, state) < 0)
+               return timeout;
+
+       /* Gather some information about the currently installed configuration
+        * and alternate interface settings.
+        */
+       if (xhci_update_timeout_for_endpoint(xhci, udev, &udev->ep0.desc,
+                       state, &timeout))
+               return timeout;
+
+       config = udev->actconfig;
+       if (!config)
+               return timeout;
+
+       for (i = 0; i < config->desc.bNumInterfaces; i++) {
+               struct usb_driver *driver;
+               struct usb_interface *intf = config->interface[i];
+
+               if (!intf)
+                       continue;
+
+               /* Check if any currently bound drivers want hub-initiated LPM
+                * disabled.
+                */
+               if (intf->dev.driver) {
+                       driver = to_usb_driver(intf->dev.driver);
+                       if (driver && driver->disable_hub_initiated_lpm) {
+                               dev_dbg(&udev->dev, "Hub-initiated %s disabled "
+                                               "at request of driver %s\n",
+                                               state_name, driver->name);
+                               return xhci_get_timeout_no_hub_lpm(udev, state);
+                       }
+               }
+
+               /* Not sure how this could happen... */
+               if (!intf->cur_altsetting)
+                       continue;
+
+               if (xhci_update_timeout_for_interface(xhci, udev,
+                                       intf->cur_altsetting,
+                                       state, &timeout))
+                       return timeout;
+       }
+       return timeout;
+}
+
+static int calculate_max_exit_latency(struct usb_device *udev,
+               enum usb3_link_state state_changed,
+               u16 hub_encoded_timeout)
+{
+       unsigned long long u1_mel_us = 0;
+       unsigned long long u2_mel_us = 0;
+       unsigned long long mel_us = 0;
+       bool disabling_u1;
+       bool disabling_u2;
+       bool enabling_u1;
+       bool enabling_u2;
+
+       disabling_u1 = (state_changed == USB3_LPM_U1 &&
+                       hub_encoded_timeout == USB3_LPM_DISABLED);
+       disabling_u2 = (state_changed == USB3_LPM_U2 &&
+                       hub_encoded_timeout == USB3_LPM_DISABLED);
+
+       enabling_u1 = (state_changed == USB3_LPM_U1 &&
+                       hub_encoded_timeout != USB3_LPM_DISABLED);
+       enabling_u2 = (state_changed == USB3_LPM_U2 &&
+                       hub_encoded_timeout != USB3_LPM_DISABLED);
+
+       /* If U1 was already enabled and we're not disabling it,
+        * or we're going to enable U1, account for the U1 max exit latency.
+        */
+       if ((udev->u1_params.timeout != USB3_LPM_DISABLED && !disabling_u1) ||
+                       enabling_u1)
+               u1_mel_us = DIV_ROUND_UP(udev->u1_params.mel, 1000);
+       if ((udev->u2_params.timeout != USB3_LPM_DISABLED && !disabling_u2) ||
+                       enabling_u2)
+               u2_mel_us = DIV_ROUND_UP(udev->u2_params.mel, 1000);
+
+       if (u1_mel_us > u2_mel_us)
+               mel_us = u1_mel_us;
+       else
+               mel_us = u2_mel_us;
+       /* xHCI host controller max exit latency field is only 16 bits wide. */
+       if (mel_us > MAX_EXIT) {
+               dev_warn(&udev->dev, "Link PM max exit latency of %lluus "
+                               "is too big.\n", mel_us);
+               return -E2BIG;
+       }
+       return mel_us;
+}
+
+/* Returns the USB3 hub-encoded value for the U1/U2 timeout. */
+int xhci_enable_usb3_lpm_timeout(struct usb_hcd *hcd,
+                       struct usb_device *udev, enum usb3_link_state state)
+{
+       struct xhci_hcd *xhci;
+       u16 hub_encoded_timeout;
+       int mel;
+       int ret;
+
+       xhci = hcd_to_xhci(hcd);
+       /* The LPM timeout values are pretty host-controller specific, so don't
+        * enable hub-initiated timeouts unless the vendor has provided
+        * information about their timeout algorithm.
+        */
+       if (!xhci || !(xhci->quirks & XHCI_LPM_SUPPORT) ||
+                       !xhci->devs[udev->slot_id])
+               return USB3_LPM_DISABLED;
+
+       hub_encoded_timeout = xhci_calculate_lpm_timeout(hcd, udev, state);
+       mel = calculate_max_exit_latency(udev, state, hub_encoded_timeout);
+       if (mel < 0) {
+               /* Max Exit Latency is too big, disable LPM. */
+               hub_encoded_timeout = USB3_LPM_DISABLED;
+               mel = 0;
+       }
+
+       ret = xhci_change_max_exit_latency(xhci, udev, mel);
+       if (ret)
+               return ret;
+       return hub_encoded_timeout;
+}
+
+int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd,
+                       struct usb_device *udev, enum usb3_link_state state)
+{
+       struct xhci_hcd *xhci;
+       u16 mel;
+       int ret;
+
+       xhci = hcd_to_xhci(hcd);
+       if (!xhci || !(xhci->quirks & XHCI_LPM_SUPPORT) ||
+                       !xhci->devs[udev->slot_id])
+               return 0;
+
+       mel = calculate_max_exit_latency(udev, state, USB3_LPM_DISABLED);
+       ret = xhci_change_max_exit_latency(xhci, udev, mel);
+       if (ret)
+               return ret;
+       return 0;
+}
+#else /* CONFIG_PM */
+
+int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
+                               struct usb_device *udev, int enable)
+{
+       return 0;
+}
+
+int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       return 0;
+}
+
+int xhci_enable_usb3_lpm_timeout(struct usb_hcd *hcd,
+                       struct usb_device *udev, enum usb3_link_state state)
+{
+       return USB3_LPM_DISABLED;
+}
+
+int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd,
+                       struct usb_device *udev, enum usb3_link_state state)
+{
+       return 0;
+}
+#endif /* CONFIG_PM */
+
+/*-------------------------------------------------------------------------*/
+
+/* Once a hub descriptor is fetched for a device, we need to update the xHC's
+ * internal data structures for the device.
+ */
+int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
+                       struct usb_tt *tt, gfp_t mem_flags)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_virt_device *vdev;
+       struct xhci_command *config_cmd;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       unsigned long flags;
+       unsigned think_time;
+       int ret;
+
+       /* Ignore root hubs */
+       if (!hdev->parent)
+               return 0;
+
+       vdev = xhci->devs[hdev->slot_id];
+       if (!vdev) {
+               xhci_warn(xhci, "Cannot update hub desc for unknown device.\n");
+               return -EINVAL;
+       }
+       config_cmd = xhci_alloc_command(xhci, true, true, mem_flags);
+       if (!config_cmd) {
+               xhci_dbg(xhci, "Could not allocate xHCI command structure.\n");
+               return -ENOMEM;
+       }
+       ctrl_ctx = xhci_get_input_control_ctx(config_cmd->in_ctx);
+       if (!ctrl_ctx) {
+               xhci_warn(xhci, "%s: Could not get input context, bad type.\n",
+                               __func__);
+               xhci_free_command(xhci, config_cmd);
+               return -ENOMEM;
+       }
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       if (hdev->speed == USB_SPEED_HIGH &&
+                       xhci_alloc_tt_info(xhci, vdev, hdev, tt, GFP_ATOMIC)) {
+               xhci_dbg(xhci, "Could not allocate xHCI TT structure.\n");
+               xhci_free_command(xhci, config_cmd);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return -ENOMEM;
+       }
+
+       xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
+       ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG);
+       slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
+       slot_ctx->dev_info |= cpu_to_le32(DEV_HUB);
+       if (tt->multi)
+               slot_ctx->dev_info |= cpu_to_le32(DEV_MTT);
+       if (xhci->hci_version > 0x95) {
+               xhci_dbg(xhci, "xHCI version %x needs hub "
+                               "TT think time and number of ports\n",
+                               (unsigned int) xhci->hci_version);
+               slot_ctx->dev_info2 |= cpu_to_le32(XHCI_MAX_PORTS(hdev->maxchild));
+               /* Set TT think time - convert from ns to FS bit times.
+                * 0 = 8 FS bit times, 1 = 16 FS bit times,
+                * 2 = 24 FS bit times, 3 = 32 FS bit times.
+                *
+                * xHCI 1.0: this field shall be 0 if the device is not a
+                * High-spped hub.
+                */
+               think_time = tt->think_time;
+               if (think_time != 0)
+                       think_time = (think_time / 666) - 1;
+               if (xhci->hci_version < 0x100 || hdev->speed == USB_SPEED_HIGH)
+                       slot_ctx->tt_info |=
+                               cpu_to_le32(TT_THINK_TIME(think_time));
+       } else {
+               xhci_dbg(xhci, "xHCI version %x doesn't need hub "
+                               "TT think time or number of ports\n",
+                               (unsigned int) xhci->hci_version);
+       }
+       slot_ctx->dev_state = 0;
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       xhci_dbg(xhci, "Set up %s for hub device.\n",
+                       (xhci->hci_version > 0x95) ?
+                       "configure endpoint" : "evaluate context");
+       xhci_dbg(xhci, "Slot %u Input Context:\n", hdev->slot_id);
+       xhci_dbg_ctx(xhci, config_cmd->in_ctx, 0);
+
+       /* Issue and wait for the configure endpoint or
+        * evaluate context command.
+        */
+       if (xhci->hci_version > 0x95)
+               ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+                               false, false);
+       else
+               ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+                               true, false);
+
+       xhci_dbg(xhci, "Slot %u Output Context:\n", hdev->slot_id);
+       xhci_dbg_ctx(xhci, vdev->out_ctx, 0);
+
+       xhci_free_command(xhci, config_cmd);
+       return ret;
+}
+
+int xhci_get_frame(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       /* EHCI mods by the periodic size.  Why? */
+       return readl(&xhci->run_regs->microframe_index) >> 3;
+}
+
+int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
+{
+       struct xhci_hcd         *xhci;
+       struct device           *dev = hcd->self.controller;
+       int                     retval;
+
+       /* Accept arbitrarily long scatter-gather lists */
+       hcd->self.sg_tablesize = ~0;
+
+       /* support to build packet from discontinuous buffers */
+       hcd->self.no_sg_constraint = 1;
+
+       /* XHCI controllers don't stop the ep queue on short packets :| */
+       hcd->self.no_stop_on_short = 1;
+
+       if (usb_hcd_is_primary_hcd(hcd)) {
+               xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
+               if (!xhci)
+                       return -ENOMEM;
+               *((struct xhci_hcd **) hcd->hcd_priv) = xhci;
+               xhci->main_hcd = hcd;
+               /* Mark the first roothub as being USB 2.0.
+                * The xHCI driver will register the USB 3.0 roothub.
+                */
+               hcd->speed = HCD_USB2;
+               hcd->self.root_hub->speed = USB_SPEED_HIGH;
+               /*
+                * USB 2.0 roothub under xHCI has an integrated TT,
+                * (rate matching hub) as opposed to having an OHCI/UHCI
+                * companion controller.
+                */
+               hcd->has_tt = 1;
+       } else {
+               /* xHCI private pointer was set in xhci_pci_probe for the second
+                * registered roothub.
+                */
+               return 0;
+       }
+
+       mutex_init(&xhci->mutex);
+       xhci->cap_regs = hcd->regs;
+       xhci->op_regs = hcd->regs +
+               HC_LENGTH(readl(&xhci->cap_regs->hc_capbase));
+       xhci->run_regs = hcd->regs +
+               (readl(&xhci->cap_regs->run_regs_off) & RTSOFF_MASK);
+       /* Cache read-only capability registers */
+       xhci->hcs_params1 = readl(&xhci->cap_regs->hcs_params1);
+       xhci->hcs_params2 = readl(&xhci->cap_regs->hcs_params2);
+       xhci->hcs_params3 = readl(&xhci->cap_regs->hcs_params3);
+       xhci->hcc_params = readl(&xhci->cap_regs->hc_capbase);
+       xhci->hci_version = HC_VERSION(xhci->hcc_params);
+       xhci->hcc_params = readl(&xhci->cap_regs->hcc_params);
+       xhci_print_registers(xhci);
+
+       xhci->quirks = quirks;
+
+       get_quirks(dev, xhci);
+
+       /* In xhci controllers which follow xhci 1.0 spec gives a spurious
+        * success event after a short transfer. This quirk will ignore such
+        * spurious event.
+        */
+       if (xhci->hci_version > 0x96)
+               xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
+
+       /* Make sure the HC is halted. */
+       retval = xhci_halt(xhci);
+       if (retval)
+               goto error;
+
+       xhci_dbg(xhci, "Resetting HCD\n");
+       /* Reset the internal HC memory state and registers. */
+       retval = xhci_reset(xhci);
+       if (retval)
+               goto error;
+       xhci_dbg(xhci, "Reset complete\n");
+
+       /* Set dma_mask and coherent_dma_mask to 64-bits,
+        * if xHC supports 64-bit addressing */
+       if (HCC_64BIT_ADDR(xhci->hcc_params) &&
+                       !dma_set_mask(dev, DMA_BIT_MASK(64))) {
+               xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
+               dma_set_coherent_mask(dev, DMA_BIT_MASK(64));
+       }
+
+       xhci_dbg(xhci, "Calling HCD init\n");
+       /* Initialize HCD and host controller data structures. */
+       retval = xhci_init(hcd);
+       if (retval)
+               goto error;
+       xhci_dbg(xhci, "Called HCD init\n");
+
+       xhci_info(xhci, "hcc params 0x%08x hci version 0x%x quirks 0x%08x\n",
+                 xhci->hcc_params, xhci->hci_version, xhci->quirks);
+
+       return 0;
+error:
+       kfree(xhci);
+       return retval;
+}
+EXPORT_SYMBOL_GPL(xhci_gen_setup);
+
+static const struct hc_driver xhci_hc_driver = {
+       .description =          "xhci-hcd",
+       .product_desc =         "xHCI Host Controller",
+       .hcd_priv_size =        sizeof(struct xhci_hcd *),
+
+       /*
+        * generic hardware linkage
+        */
+       .irq =                  xhci_irq,
+       .flags =                HCD_MEMORY | HCD_USB3 | HCD_SHARED,
+
+       /*
+        * basic lifecycle operations
+        */
+       .reset =                NULL, /* set in xhci_init_driver() */
+       .start =                xhci_run,
+       .stop =                 xhci_stop,
+       .shutdown =             xhci_shutdown,
+
+       /*
+        * managing i/o requests and associated device resources
+        */
+       .urb_enqueue =          xhci_urb_enqueue,
+       .urb_dequeue =          xhci_urb_dequeue,
+       .alloc_dev =            xhci_alloc_dev,
+       .free_dev =             xhci_free_dev,
+       .alloc_streams =        xhci_alloc_streams,
+       .free_streams =         xhci_free_streams,
+       .add_endpoint =         xhci_add_endpoint,
+       .drop_endpoint =        xhci_drop_endpoint,
+       .endpoint_reset =       xhci_endpoint_reset,
+       .check_bandwidth =      xhci_check_bandwidth,
+       .reset_bandwidth =      xhci_reset_bandwidth,
+       .address_device =       xhci_address_device,
+       .enable_device =        xhci_enable_device,
+       .update_hub_device =    xhci_update_hub_device,
+       .reset_device =         xhci_discover_or_reset_device,
+
+       /*
+        * scheduling support
+        */
+       .get_frame_number =     xhci_get_frame,
+
+       /*
+        * root hub support
+        */
+       .hub_control =          xhci_hub_control,
+       .hub_status_data =      xhci_hub_status_data,
+       .bus_suspend =          xhci_bus_suspend,
+       .bus_resume =           xhci_bus_resume,
+
+       /*
+        * call back when device connected and addressed
+        */
+       .update_device =        xhci_update_device,
+       .set_usb2_hw_lpm =      xhci_set_usb2_hardware_lpm,
+       .enable_usb3_lpm_timeout =      xhci_enable_usb3_lpm_timeout,
+       .disable_usb3_lpm_timeout =     xhci_disable_usb3_lpm_timeout,
+       .find_raw_port_number = xhci_find_raw_port_number,
+};
+
+void xhci_init_driver(struct hc_driver *drv, int (*setup_fn)(struct usb_hcd *))
+{
+       BUG_ON(!setup_fn);
+       *drv = xhci_hc_driver;
+       drv->reset = setup_fn;
+}
+EXPORT_SYMBOL_GPL(xhci_init_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_LICENSE("GPL");
+
+static int __init xhci_hcd_init(void)
+{
+       /*
+        * Check the compiler generated sizes of structures that must be laid
+        * out in specific ways for hardware access.
+        */
+       BUILD_BUG_ON(sizeof(struct xhci_doorbell_array) != 256*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_slot_ctx) != 8*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_ep_ctx) != 8*32/8);
+       /* xhci_device_control has eight fields, and also
+        * embeds one xhci_slot_ctx and 31 xhci_ep_ctx
+        */
+       BUILD_BUG_ON(sizeof(struct xhci_stream_ctx) != 4*32/8);
+       BUILD_BUG_ON(sizeof(union xhci_trb) != 4*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_erst_entry) != 4*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_cap_regs) != 7*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
+       /* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
+       BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
+       return 0;
+}
+
+/*
+ * If an init function is provided, an exit function must also be provided
+ * to allow module unload.
+ */
+static void __exit xhci_hcd_fini(void) { }
+
+module_init(xhci_hcd_init);
+module_exit(xhci_hcd_fini);