Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / host / whci / qset.c
diff --git a/kernel/drivers/usb/host/whci/qset.c b/kernel/drivers/usb/host/whci/qset.c
new file mode 100644 (file)
index 0000000..dc31c42
--- /dev/null
@@ -0,0 +1,835 @@
+/*
+ * Wireless Host Controller (WHC) qset management.
+ *
+ * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/uwb/umc.h>
+#include <linux/usb.h>
+
+#include "../../wusbcore/wusbhc.h"
+
+#include "whcd.h"
+
+struct whc_qset *qset_alloc(struct whc *whc, gfp_t mem_flags)
+{
+       struct whc_qset *qset;
+       dma_addr_t dma;
+
+       qset = dma_pool_alloc(whc->qset_pool, mem_flags, &dma);
+       if (qset == NULL)
+               return NULL;
+       memset(qset, 0, sizeof(struct whc_qset));
+
+       qset->qset_dma = dma;
+       qset->whc = whc;
+
+       INIT_LIST_HEAD(&qset->list_node);
+       INIT_LIST_HEAD(&qset->stds);
+
+       return qset;
+}
+
+/**
+ * qset_fill_qh - fill the static endpoint state in a qset's QHead
+ * @qset: the qset whose QH needs initializing with static endpoint
+ *        state
+ * @urb:  an urb for a transfer to this endpoint
+ */
+static void qset_fill_qh(struct whc *whc, struct whc_qset *qset, struct urb *urb)
+{
+       struct usb_device *usb_dev = urb->dev;
+       struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
+       struct usb_wireless_ep_comp_descriptor *epcd;
+       bool is_out;
+       uint8_t phy_rate;
+
+       is_out = usb_pipeout(urb->pipe);
+
+       qset->max_packet = le16_to_cpu(urb->ep->desc.wMaxPacketSize);
+
+       epcd = (struct usb_wireless_ep_comp_descriptor *)qset->ep->extra;
+       if (epcd) {
+               qset->max_seq = epcd->bMaxSequence;
+               qset->max_burst = epcd->bMaxBurst;
+       } else {
+               qset->max_seq = 2;
+               qset->max_burst = 1;
+       }
+
+       /*
+        * Initial PHY rate is 53.3 Mbit/s for control endpoints or
+        * the maximum supported by the device for other endpoints
+        * (unless limited by the user).
+        */
+       if (usb_pipecontrol(urb->pipe))
+               phy_rate = UWB_PHY_RATE_53;
+       else {
+               uint16_t phy_rates;
+
+               phy_rates = le16_to_cpu(wusb_dev->wusb_cap_descr->wPHYRates);
+               phy_rate = fls(phy_rates) - 1;
+               if (phy_rate > whc->wusbhc.phy_rate)
+                       phy_rate = whc->wusbhc.phy_rate;
+       }
+
+       qset->qh.info1 = cpu_to_le32(
+               QH_INFO1_EP(usb_pipeendpoint(urb->pipe))
+               | (is_out ? QH_INFO1_DIR_OUT : QH_INFO1_DIR_IN)
+               | usb_pipe_to_qh_type(urb->pipe)
+               | QH_INFO1_DEV_INFO_IDX(wusb_port_no_to_idx(usb_dev->portnum))
+               | QH_INFO1_MAX_PKT_LEN(qset->max_packet)
+               );
+       qset->qh.info2 = cpu_to_le32(
+               QH_INFO2_BURST(qset->max_burst)
+               | QH_INFO2_DBP(0)
+               | QH_INFO2_MAX_COUNT(3)
+               | QH_INFO2_MAX_RETRY(3)
+               | QH_INFO2_MAX_SEQ(qset->max_seq - 1)
+               );
+       /* FIXME: where can we obtain these Tx parameters from?  Why
+        * doesn't the chip know what Tx power to use? It knows the Rx
+        * strength and can presumably guess the Tx power required
+        * from that? */
+       qset->qh.info3 = cpu_to_le32(
+               QH_INFO3_TX_RATE(phy_rate)
+               | QH_INFO3_TX_PWR(0) /* 0 == max power */
+               );
+
+       qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
+}
+
+/**
+ * qset_clear - clear fields in a qset so it may be reinserted into a
+ * schedule.
+ *
+ * The sequence number and current window are not cleared (see
+ * qset_reset()).
+ */
+void qset_clear(struct whc *whc, struct whc_qset *qset)
+{
+       qset->td_start = qset->td_end = qset->ntds = 0;
+
+       qset->qh.link = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
+       qset->qh.status = qset->qh.status & QH_STATUS_SEQ_MASK;
+       qset->qh.err_count = 0;
+       qset->qh.scratch[0] = 0;
+       qset->qh.scratch[1] = 0;
+       qset->qh.scratch[2] = 0;
+
+       memset(&qset->qh.overlay, 0, sizeof(qset->qh.overlay));
+
+       init_completion(&qset->remove_complete);
+}
+
+/**
+ * qset_reset - reset endpoint state in a qset.
+ *
+ * Clears the sequence number and current window.  This qset must not
+ * be in the ASL or PZL.
+ */
+void qset_reset(struct whc *whc, struct whc_qset *qset)
+{
+       qset->reset = 0;
+
+       qset->qh.status &= ~QH_STATUS_SEQ_MASK;
+       qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
+}
+
+/**
+ * get_qset - get the qset for an async endpoint
+ *
+ * A new qset is created if one does not already exist.
+ */
+struct whc_qset *get_qset(struct whc *whc, struct urb *urb,
+                                gfp_t mem_flags)
+{
+       struct whc_qset *qset;
+
+       qset = urb->ep->hcpriv;
+       if (qset == NULL) {
+               qset = qset_alloc(whc, mem_flags);
+               if (qset == NULL)
+                       return NULL;
+
+               qset->ep = urb->ep;
+               urb->ep->hcpriv = qset;
+               qset_fill_qh(whc, qset, urb);
+       }
+       return qset;
+}
+
+void qset_remove_complete(struct whc *whc, struct whc_qset *qset)
+{
+       qset->remove = 0;
+       list_del_init(&qset->list_node);
+       complete(&qset->remove_complete);
+}
+
+/**
+ * qset_add_qtds - add qTDs for an URB to a qset
+ *
+ * Returns true if the list (ASL/PZL) must be updated because (for a
+ * WHCI 0.95 controller) an activated qTD was pointed to be iCur.
+ */
+enum whc_update qset_add_qtds(struct whc *whc, struct whc_qset *qset)
+{
+       struct whc_std *std;
+       enum whc_update update = 0;
+
+       list_for_each_entry(std, &qset->stds, list_node) {
+               struct whc_qtd *qtd;
+               uint32_t status;
+
+               if (qset->ntds >= WHCI_QSET_TD_MAX
+                   || (qset->pause_after_urb && std->urb != qset->pause_after_urb))
+                       break;
+
+               if (std->qtd)
+                       continue; /* already has a qTD */
+
+               qtd = std->qtd = &qset->qtd[qset->td_end];
+
+               /* Fill in setup bytes for control transfers. */
+               if (usb_pipecontrol(std->urb->pipe))
+                       memcpy(qtd->setup, std->urb->setup_packet, 8);
+
+               status = QTD_STS_ACTIVE | QTD_STS_LEN(std->len);
+
+               if (whc_std_last(std) && usb_pipeout(std->urb->pipe))
+                       status |= QTD_STS_LAST_PKT;
+
+               /*
+                * For an IN transfer the iAlt field should be set so
+                * the h/w will automatically advance to the next
+                * transfer. However, if there are 8 or more TDs
+                * remaining in this transfer then iAlt cannot be set
+                * as it could point to somewhere in this transfer.
+                */
+               if (std->ntds_remaining < WHCI_QSET_TD_MAX) {
+                       int ialt;
+                       ialt = (qset->td_end + std->ntds_remaining) % WHCI_QSET_TD_MAX;
+                       status |= QTD_STS_IALT(ialt);
+               } else if (usb_pipein(std->urb->pipe))
+                       qset->pause_after_urb = std->urb;
+
+               if (std->num_pointers)
+                       qtd->options = cpu_to_le32(QTD_OPT_IOC);
+               else
+                       qtd->options = cpu_to_le32(QTD_OPT_IOC | QTD_OPT_SMALL);
+               qtd->page_list_ptr = cpu_to_le64(std->dma_addr);
+
+               qtd->status = cpu_to_le32(status);
+
+               if (QH_STATUS_TO_ICUR(qset->qh.status) == qset->td_end)
+                       update = WHC_UPDATE_UPDATED;
+
+               if (++qset->td_end >= WHCI_QSET_TD_MAX)
+                       qset->td_end = 0;
+               qset->ntds++;
+       }
+
+       return update;
+}
+
+/**
+ * qset_remove_qtd - remove the first qTD from a qset.
+ *
+ * The qTD might be still active (if it's part of a IN URB that
+ * resulted in a short read) so ensure it's deactivated.
+ */
+static void qset_remove_qtd(struct whc *whc, struct whc_qset *qset)
+{
+       qset->qtd[qset->td_start].status = 0;
+
+       if (++qset->td_start >= WHCI_QSET_TD_MAX)
+               qset->td_start = 0;
+       qset->ntds--;
+}
+
+static void qset_copy_bounce_to_sg(struct whc *whc, struct whc_std *std)
+{
+       struct scatterlist *sg;
+       void *bounce;
+       size_t remaining, offset;
+
+       bounce = std->bounce_buf;
+       remaining = std->len;
+
+       sg = std->bounce_sg;
+       offset = std->bounce_offset;
+
+       while (remaining) {
+               size_t len;
+
+               len = min(sg->length - offset, remaining);
+               memcpy(sg_virt(sg) + offset, bounce, len);
+
+               bounce += len;
+               remaining -= len;
+
+               offset += len;
+               if (offset >= sg->length) {
+                       sg = sg_next(sg);
+                       offset = 0;
+               }
+       }
+
+}
+
+/**
+ * qset_free_std - remove an sTD and free it.
+ * @whc: the WHCI host controller
+ * @std: the sTD to remove and free.
+ */
+void qset_free_std(struct whc *whc, struct whc_std *std)
+{
+       list_del(&std->list_node);
+       if (std->bounce_buf) {
+               bool is_out = usb_pipeout(std->urb->pipe);
+               dma_addr_t dma_addr;
+
+               if (std->num_pointers)
+                       dma_addr = le64_to_cpu(std->pl_virt[0].buf_ptr);
+               else
+                       dma_addr = std->dma_addr;
+
+               dma_unmap_single(whc->wusbhc.dev, dma_addr,
+                                std->len, is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+               if (!is_out)
+                       qset_copy_bounce_to_sg(whc, std);
+               kfree(std->bounce_buf);
+       }
+       if (std->pl_virt) {
+               if (std->dma_addr)
+                       dma_unmap_single(whc->wusbhc.dev, std->dma_addr,
+                                        std->num_pointers * sizeof(struct whc_page_list_entry),
+                                        DMA_TO_DEVICE);
+               kfree(std->pl_virt);
+               std->pl_virt = NULL;
+       }
+       kfree(std);
+}
+
+/**
+ * qset_remove_qtds - remove an URB's qTDs (and sTDs).
+ */
+static void qset_remove_qtds(struct whc *whc, struct whc_qset *qset,
+                            struct urb *urb)
+{
+       struct whc_std *std, *t;
+
+       list_for_each_entry_safe(std, t, &qset->stds, list_node) {
+               if (std->urb != urb)
+                       break;
+               if (std->qtd != NULL)
+                       qset_remove_qtd(whc, qset);
+               qset_free_std(whc, std);
+       }
+}
+
+/**
+ * qset_free_stds - free any remaining sTDs for an URB.
+ */
+static void qset_free_stds(struct whc_qset *qset, struct urb *urb)
+{
+       struct whc_std *std, *t;
+
+       list_for_each_entry_safe(std, t, &qset->stds, list_node) {
+               if (std->urb == urb)
+                       qset_free_std(qset->whc, std);
+       }
+}
+
+static int qset_fill_page_list(struct whc *whc, struct whc_std *std, gfp_t mem_flags)
+{
+       dma_addr_t dma_addr = std->dma_addr;
+       dma_addr_t sp, ep;
+       size_t pl_len;
+       int p;
+
+       /* Short buffers don't need a page list. */
+       if (std->len <= WHCI_PAGE_SIZE) {
+               std->num_pointers = 0;
+               return 0;
+       }
+
+       sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
+       ep = dma_addr + std->len;
+       std->num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
+
+       pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
+       std->pl_virt = kmalloc(pl_len, mem_flags);
+       if (std->pl_virt == NULL)
+               return -ENOMEM;
+       std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, pl_len, DMA_TO_DEVICE);
+
+       for (p = 0; p < std->num_pointers; p++) {
+               std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
+               dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
+       }
+
+       return 0;
+}
+
+/**
+ * urb_dequeue_work - executes asl/pzl update and gives back the urb to the system.
+ */
+static void urb_dequeue_work(struct work_struct *work)
+{
+       struct whc_urb *wurb = container_of(work, struct whc_urb, dequeue_work);
+       struct whc_qset *qset = wurb->qset;
+       struct whc *whc = qset->whc;
+       unsigned long flags;
+
+       if (wurb->is_async == true)
+               asl_update(whc, WUSBCMD_ASYNC_UPDATED
+                          | WUSBCMD_ASYNC_SYNCED_DB
+                          | WUSBCMD_ASYNC_QSET_RM);
+       else
+               pzl_update(whc, WUSBCMD_PERIODIC_UPDATED
+                          | WUSBCMD_PERIODIC_SYNCED_DB
+                          | WUSBCMD_PERIODIC_QSET_RM);
+
+       spin_lock_irqsave(&whc->lock, flags);
+       qset_remove_urb(whc, qset, wurb->urb, wurb->status);
+       spin_unlock_irqrestore(&whc->lock, flags);
+}
+
+static struct whc_std *qset_new_std(struct whc *whc, struct whc_qset *qset,
+                                   struct urb *urb, gfp_t mem_flags)
+{
+       struct whc_std *std;
+
+       std = kzalloc(sizeof(struct whc_std), mem_flags);
+       if (std == NULL)
+               return NULL;
+
+       std->urb = urb;
+       std->qtd = NULL;
+
+       INIT_LIST_HEAD(&std->list_node);
+       list_add_tail(&std->list_node, &qset->stds);
+
+       return std;
+}
+
+static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *urb,
+                          gfp_t mem_flags)
+{
+       size_t remaining;
+       struct scatterlist *sg;
+       int i;
+       int ntds = 0;
+       struct whc_std *std = NULL;
+       struct whc_page_list_entry *new_pl_virt;
+       dma_addr_t prev_end = 0;
+       size_t pl_len;
+       int p = 0;
+
+       remaining = urb->transfer_buffer_length;
+
+       for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
+               dma_addr_t dma_addr;
+               size_t dma_remaining;
+               dma_addr_t sp, ep;
+               int num_pointers;
+
+               if (remaining == 0) {
+                       break;
+               }
+
+               dma_addr = sg_dma_address(sg);
+               dma_remaining = min_t(size_t, sg_dma_len(sg), remaining);
+
+               while (dma_remaining) {
+                       size_t dma_len;
+
+                       /*
+                        * We can use the previous std (if it exists) provided that:
+                        * - the previous one ended on a page boundary.
+                        * - the current one begins on a page boundary.
+                        * - the previous one isn't full.
+                        *
+                        * If a new std is needed but the previous one
+                        * was not a whole number of packets then this
+                        * sg list cannot be mapped onto multiple
+                        * qTDs.  Return an error and let the caller
+                        * sort it out.
+                        */
+                       if (!std
+                           || (prev_end & (WHCI_PAGE_SIZE-1))
+                           || (dma_addr & (WHCI_PAGE_SIZE-1))
+                           || std->len + WHCI_PAGE_SIZE > QTD_MAX_XFER_SIZE) {
+                               if (std && std->len % qset->max_packet != 0)
+                                       return -EINVAL;
+                               std = qset_new_std(whc, qset, urb, mem_flags);
+                               if (std == NULL) {
+                                       return -ENOMEM;
+                               }
+                               ntds++;
+                               p = 0;
+                       }
+
+                       dma_len = dma_remaining;
+
+                       /*
+                        * If the remainder of this element doesn't
+                        * fit in a single qTD, limit the qTD to a
+                        * whole number of packets.  This allows the
+                        * remainder to go into the next qTD.
+                        */
+                       if (std->len + dma_len > QTD_MAX_XFER_SIZE) {
+                               dma_len = (QTD_MAX_XFER_SIZE / qset->max_packet)
+                                       * qset->max_packet - std->len;
+                       }
+
+                       std->len += dma_len;
+                       std->ntds_remaining = -1; /* filled in later */
+
+                       sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
+                       ep = dma_addr + dma_len;
+                       num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
+                       std->num_pointers += num_pointers;
+
+                       pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
+
+                       new_pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
+                       if (new_pl_virt == NULL) {
+                               kfree(std->pl_virt);
+                               std->pl_virt = NULL;
+                               return -ENOMEM;
+                       }
+                       std->pl_virt = new_pl_virt;
+
+                       for (;p < std->num_pointers; p++) {
+                               std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
+                               dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
+                       }
+
+                       prev_end = dma_addr = ep;
+                       dma_remaining -= dma_len;
+                       remaining -= dma_len;
+               }
+       }
+
+       /* Now the number of stds is know, go back and fill in
+          std->ntds_remaining. */
+       list_for_each_entry(std, &qset->stds, list_node) {
+               if (std->ntds_remaining == -1) {
+                       pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
+                       std->ntds_remaining = ntds--;
+                       std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt,
+                                                      pl_len, DMA_TO_DEVICE);
+               }
+       }
+       return 0;
+}
+
+/**
+ * qset_add_urb_sg_linearize - add an urb with sg list, copying the data
+ *
+ * If the URB contains an sg list whose elements cannot be directly
+ * mapped to qTDs then the data must be transferred via bounce
+ * buffers.
+ */
+static int qset_add_urb_sg_linearize(struct whc *whc, struct whc_qset *qset,
+                                    struct urb *urb, gfp_t mem_flags)
+{
+       bool is_out = usb_pipeout(urb->pipe);
+       size_t max_std_len;
+       size_t remaining;
+       int ntds = 0;
+       struct whc_std *std = NULL;
+       void *bounce = NULL;
+       struct scatterlist *sg;
+       int i;
+
+       /* limit maximum bounce buffer to 16 * 3.5 KiB ~= 28 k */
+       max_std_len = qset->max_burst * qset->max_packet;
+
+       remaining = urb->transfer_buffer_length;
+
+       for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
+               size_t len;
+               size_t sg_remaining;
+               void *orig;
+
+               if (remaining == 0) {
+                       break;
+               }
+
+               sg_remaining = min_t(size_t, remaining, sg->length);
+               orig = sg_virt(sg);
+
+               while (sg_remaining) {
+                       if (!std || std->len == max_std_len) {
+                               std = qset_new_std(whc, qset, urb, mem_flags);
+                               if (std == NULL)
+                                       return -ENOMEM;
+                               std->bounce_buf = kmalloc(max_std_len, mem_flags);
+                               if (std->bounce_buf == NULL)
+                                       return -ENOMEM;
+                               std->bounce_sg = sg;
+                               std->bounce_offset = orig - sg_virt(sg);
+                               bounce = std->bounce_buf;
+                               ntds++;
+                       }
+
+                       len = min(sg_remaining, max_std_len - std->len);
+
+                       if (is_out)
+                               memcpy(bounce, orig, len);
+
+                       std->len += len;
+                       std->ntds_remaining = -1; /* filled in later */
+
+                       bounce += len;
+                       orig += len;
+                       sg_remaining -= len;
+                       remaining -= len;
+               }
+       }
+
+       /*
+        * For each of the new sTDs, map the bounce buffers, create
+        * page lists (if necessary), and fill in std->ntds_remaining.
+        */
+       list_for_each_entry(std, &qset->stds, list_node) {
+               if (std->ntds_remaining != -1)
+                       continue;
+
+               std->dma_addr = dma_map_single(&whc->umc->dev, std->bounce_buf, std->len,
+                                              is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+               if (qset_fill_page_list(whc, std, mem_flags) < 0)
+                       return -ENOMEM;
+
+               std->ntds_remaining = ntds--;
+       }
+
+       return 0;
+}
+
+/**
+ * qset_add_urb - add an urb to the qset's queue.
+ *
+ * The URB is chopped into sTDs, one for each qTD that will required.
+ * At least one qTD (and sTD) is required even if the transfer has no
+ * data (e.g., for some control transfers).
+ */
+int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb,
+       gfp_t mem_flags)
+{
+       struct whc_urb *wurb;
+       int remaining = urb->transfer_buffer_length;
+       u64 transfer_dma = urb->transfer_dma;
+       int ntds_remaining;
+       int ret;
+
+       wurb = kzalloc(sizeof(struct whc_urb), mem_flags);
+       if (wurb == NULL)
+               goto err_no_mem;
+       urb->hcpriv = wurb;
+       wurb->qset = qset;
+       wurb->urb = urb;
+       INIT_WORK(&wurb->dequeue_work, urb_dequeue_work);
+
+       if (urb->num_sgs) {
+               ret = qset_add_urb_sg(whc, qset, urb, mem_flags);
+               if (ret == -EINVAL) {
+                       qset_free_stds(qset, urb);
+                       ret = qset_add_urb_sg_linearize(whc, qset, urb, mem_flags);
+               }
+               if (ret < 0)
+                       goto err_no_mem;
+               return 0;
+       }
+
+       ntds_remaining = DIV_ROUND_UP(remaining, QTD_MAX_XFER_SIZE);
+       if (ntds_remaining == 0)
+               ntds_remaining = 1;
+
+       while (ntds_remaining) {
+               struct whc_std *std;
+               size_t std_len;
+
+               std_len = remaining;
+               if (std_len > QTD_MAX_XFER_SIZE)
+                       std_len = QTD_MAX_XFER_SIZE;
+
+               std = qset_new_std(whc, qset, urb, mem_flags);
+               if (std == NULL)
+                       goto err_no_mem;
+
+               std->dma_addr = transfer_dma;
+               std->len = std_len;
+               std->ntds_remaining = ntds_remaining;
+
+               if (qset_fill_page_list(whc, std, mem_flags) < 0)
+                       goto err_no_mem;
+
+               ntds_remaining--;
+               remaining -= std_len;
+               transfer_dma += std_len;
+       }
+
+       return 0;
+
+err_no_mem:
+       qset_free_stds(qset, urb);
+       return -ENOMEM;
+}
+
+/**
+ * qset_remove_urb - remove an URB from the urb queue.
+ *
+ * The URB is returned to the USB subsystem.
+ */
+void qset_remove_urb(struct whc *whc, struct whc_qset *qset,
+                           struct urb *urb, int status)
+{
+       struct wusbhc *wusbhc = &whc->wusbhc;
+       struct whc_urb *wurb = urb->hcpriv;
+
+       usb_hcd_unlink_urb_from_ep(&wusbhc->usb_hcd, urb);
+       /* Drop the lock as urb->complete() may enqueue another urb. */
+       spin_unlock(&whc->lock);
+       wusbhc_giveback_urb(wusbhc, urb, status);
+       spin_lock(&whc->lock);
+
+       kfree(wurb);
+}
+
+/**
+ * get_urb_status_from_qtd - get the completed urb status from qTD status
+ * @urb:    completed urb
+ * @status: qTD status
+ */
+static int get_urb_status_from_qtd(struct urb *urb, u32 status)
+{
+       if (status & QTD_STS_HALTED) {
+               if (status & QTD_STS_DBE)
+                       return usb_pipein(urb->pipe) ? -ENOSR : -ECOMM;
+               else if (status & QTD_STS_BABBLE)
+                       return -EOVERFLOW;
+               else if (status & QTD_STS_RCE)
+                       return -ETIME;
+               return -EPIPE;
+       }
+       if (usb_pipein(urb->pipe)
+           && (urb->transfer_flags & URB_SHORT_NOT_OK)
+           && urb->actual_length < urb->transfer_buffer_length)
+               return -EREMOTEIO;
+       return 0;
+}
+
+/**
+ * process_inactive_qtd - process an inactive (but not halted) qTD.
+ *
+ * Update the urb with the transfer bytes from the qTD, if the urb is
+ * completely transferred or (in the case of an IN only) the LPF is
+ * set, then the transfer is complete and the urb should be returned
+ * to the system.
+ */
+void process_inactive_qtd(struct whc *whc, struct whc_qset *qset,
+                                struct whc_qtd *qtd)
+{
+       struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
+       struct urb *urb = std->urb;
+       uint32_t status;
+       bool complete;
+
+       status = le32_to_cpu(qtd->status);
+
+       urb->actual_length += std->len - QTD_STS_TO_LEN(status);
+
+       if (usb_pipein(urb->pipe) && (status & QTD_STS_LAST_PKT))
+               complete = true;
+       else
+               complete = whc_std_last(std);
+
+       qset_remove_qtd(whc, qset);
+       qset_free_std(whc, std);
+
+       /*
+        * Transfers for this URB are complete?  Then return it to the
+        * USB subsystem.
+        */
+       if (complete) {
+               qset_remove_qtds(whc, qset, urb);
+               qset_remove_urb(whc, qset, urb, get_urb_status_from_qtd(urb, status));
+
+               /*
+                * If iAlt isn't valid then the hardware didn't
+                * advance iCur. Adjust the start and end pointers to
+                * match iCur.
+                */
+               if (!(status & QTD_STS_IALT_VALID))
+                       qset->td_start = qset->td_end
+                               = QH_STATUS_TO_ICUR(le16_to_cpu(qset->qh.status));
+               qset->pause_after_urb = NULL;
+       }
+}
+
+/**
+ * process_halted_qtd - process a qset with a halted qtd
+ *
+ * Remove all the qTDs for the failed URB and return the failed URB to
+ * the USB subsystem.  Then remove all other qTDs so the qset can be
+ * removed.
+ *
+ * FIXME: this is the point where rate adaptation can be done.  If a
+ * transfer failed because it exceeded the maximum number of retries
+ * then it could be reactivated with a slower rate without having to
+ * remove the qset.
+ */
+void process_halted_qtd(struct whc *whc, struct whc_qset *qset,
+                              struct whc_qtd *qtd)
+{
+       struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
+       struct urb *urb = std->urb;
+       int urb_status;
+
+       urb_status = get_urb_status_from_qtd(urb, le32_to_cpu(qtd->status));
+
+       qset_remove_qtds(whc, qset, urb);
+       qset_remove_urb(whc, qset, urb, urb_status);
+
+       list_for_each_entry(std, &qset->stds, list_node) {
+               if (qset->ntds == 0)
+                       break;
+               qset_remove_qtd(whc, qset);
+               std->qtd = NULL;
+       }
+
+       qset->remove = 1;
+}
+
+void qset_free(struct whc *whc, struct whc_qset *qset)
+{
+       dma_pool_free(whc->qset_pool, qset, qset->qset_dma);
+}
+
+/**
+ * qset_delete - wait for a qset to be unused, then free it.
+ */
+void qset_delete(struct whc *whc, struct whc_qset *qset)
+{
+       wait_for_completion(&qset->remove_complete);
+       qset_free(whc, qset);
+}