Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / wimax / i2400m / driver.c
diff --git a/kernel/drivers/net/wimax/i2400m/driver.c b/kernel/drivers/net/wimax/i2400m/driver.c
new file mode 100644 (file)
index 0000000..9c78090
--- /dev/null
@@ -0,0 +1,1025 @@
+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Generic probe/disconnect, reset and message passing
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * See i2400m.h for driver documentation. This contains helpers for
+ * the driver model glue [_setup()/_release()], handling device resets
+ * [_dev_reset_handle()], and the backends for the WiMAX stack ops
+ * reset [_op_reset()] and message from user [_op_msg_from_user()].
+ *
+ * ROADMAP:
+ *
+ * i2400m_op_msg_from_user()
+ *   i2400m_msg_to_dev()
+ *   wimax_msg_to_user_send()
+ *
+ * i2400m_op_reset()
+ *   i240m->bus_reset()
+ *
+ * i2400m_dev_reset_handle()
+ *   __i2400m_dev_reset_handle()
+ *     __i2400m_dev_stop()
+ *     __i2400m_dev_start()
+ *
+ * i2400m_setup()
+ *   i2400m->bus_setup()
+ *   i2400m_bootrom_init()
+ *   register_netdev()
+ *   wimax_dev_add()
+ *   i2400m_dev_start()
+ *     __i2400m_dev_start()
+ *       i2400m_dev_bootstrap()
+ *       i2400m_tx_setup()
+ *       i2400m->bus_dev_start()
+ *       i2400m_firmware_check()
+ *       i2400m_check_mac_addr()
+ *
+ * i2400m_release()
+ *   i2400m_dev_stop()
+ *     __i2400m_dev_stop()
+ *       i2400m_dev_shutdown()
+ *       i2400m->bus_dev_stop()
+ *       i2400m_tx_release()
+ *   i2400m->bus_release()
+ *   wimax_dev_rm()
+ *   unregister_netdev()
+ */
+#include "i2400m.h"
+#include <linux/etherdevice.h>
+#include <linux/wimax/i2400m.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+
+#define D_SUBMODULE driver
+#include "debug-levels.h"
+
+
+static char i2400m_debug_params[128];
+module_param_string(debug, i2400m_debug_params, sizeof(i2400m_debug_params),
+                   0644);
+MODULE_PARM_DESC(debug,
+                "String of space-separated NAME:VALUE pairs, where NAMEs "
+                "are the different debug submodules and VALUE are the "
+                "initial debug value to set.");
+
+static char i2400m_barkers_params[128];
+module_param_string(barkers, i2400m_barkers_params,
+                   sizeof(i2400m_barkers_params), 0644);
+MODULE_PARM_DESC(barkers,
+                "String of comma-separated 32-bit values; each is "
+                "recognized as the value the device sends as a reboot "
+                "signal; values are appended to a list--setting one value "
+                "as zero cleans the existing list and starts a new one.");
+
+/*
+ * WiMAX stack operation: relay a message from user space
+ *
+ * @wimax_dev: device descriptor
+ * @pipe_name: named pipe the message is for
+ * @msg_buf: pointer to the message bytes
+ * @msg_len: length of the buffer
+ * @genl_info: passed by the generic netlink layer
+ *
+ * The WiMAX stack will call this function when a message was received
+ * from user space.
+ *
+ * For the i2400m, this is an L3L4 message, as specified in
+ * include/linux/wimax/i2400m.h, and thus prefixed with a 'struct
+ * i2400m_l3l4_hdr'. Driver (and device) expect the messages to be
+ * coded in Little Endian.
+ *
+ * This function just verifies that the header declaration and the
+ * payload are consistent and then deals with it, either forwarding it
+ * to the device or procesing it locally.
+ *
+ * In the i2400m, messages are basically commands that will carry an
+ * ack, so we use i2400m_msg_to_dev() and then deliver the ack back to
+ * user space. The rx.c code might intercept the response and use it
+ * to update the driver's state, but then it will pass it on so it can
+ * be relayed back to user space.
+ *
+ * Note that asynchronous events from the device are processed and
+ * sent to user space in rx.c.
+ */
+static
+int i2400m_op_msg_from_user(struct wimax_dev *wimax_dev,
+                           const char *pipe_name,
+                           const void *msg_buf, size_t msg_len,
+                           const struct genl_info *genl_info)
+{
+       int result;
+       struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
+       struct device *dev = i2400m_dev(i2400m);
+       struct sk_buff *ack_skb;
+
+       d_fnstart(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p "
+                 "msg_len %zu genl_info %p)\n", wimax_dev, i2400m,
+                 msg_buf, msg_len, genl_info);
+       ack_skb = i2400m_msg_to_dev(i2400m, msg_buf, msg_len);
+       result = PTR_ERR(ack_skb);
+       if (IS_ERR(ack_skb))
+               goto error_msg_to_dev;
+       result = wimax_msg_send(&i2400m->wimax_dev, ack_skb);
+error_msg_to_dev:
+       d_fnend(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p msg_len %zu "
+               "genl_info %p) = %d\n", wimax_dev, i2400m, msg_buf, msg_len,
+               genl_info, result);
+       return result;
+}
+
+
+/*
+ * Context to wait for a reset to finalize
+ */
+struct i2400m_reset_ctx {
+       struct completion completion;
+       int result;
+};
+
+
+/*
+ * WiMAX stack operation: reset a device
+ *
+ * @wimax_dev: device descriptor
+ *
+ * See the documentation for wimax_reset() and wimax_dev->op_reset for
+ * the requirements of this function. The WiMAX stack guarantees
+ * serialization on calls to this function.
+ *
+ * Do a warm reset on the device; if it fails, resort to a cold reset
+ * and return -ENODEV. On successful warm reset, we need to block
+ * until it is complete.
+ *
+ * The bus-driver implementation of reset takes care of falling back
+ * to cold reset if warm fails.
+ */
+static
+int i2400m_op_reset(struct wimax_dev *wimax_dev)
+{
+       int result;
+       struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
+       struct device *dev = i2400m_dev(i2400m);
+       struct i2400m_reset_ctx ctx = {
+               .completion = COMPLETION_INITIALIZER_ONSTACK(ctx.completion),
+               .result = 0,
+       };
+
+       d_fnstart(4, dev, "(wimax_dev %p)\n", wimax_dev);
+       mutex_lock(&i2400m->init_mutex);
+       i2400m->reset_ctx = &ctx;
+       mutex_unlock(&i2400m->init_mutex);
+       result = i2400m_reset(i2400m, I2400M_RT_WARM);
+       if (result < 0)
+               goto out;
+       result = wait_for_completion_timeout(&ctx.completion, 4*HZ);
+       if (result == 0)
+               result = -ETIMEDOUT;
+       else if (result > 0)
+               result = ctx.result;
+       /* if result < 0, pass it on */
+       mutex_lock(&i2400m->init_mutex);
+       i2400m->reset_ctx = NULL;
+       mutex_unlock(&i2400m->init_mutex);
+out:
+       d_fnend(4, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
+       return result;
+}
+
+
+/*
+ * Check the MAC address we got from boot mode is ok
+ *
+ * @i2400m: device descriptor
+ *
+ * Returns: 0 if ok, < 0 errno code on error.
+ */
+static
+int i2400m_check_mac_addr(struct i2400m *i2400m)
+{
+       int result;
+       struct device *dev = i2400m_dev(i2400m);
+       struct sk_buff *skb;
+       const struct i2400m_tlv_detailed_device_info *ddi;
+       struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       skb = i2400m_get_device_info(i2400m);
+       if (IS_ERR(skb)) {
+               result = PTR_ERR(skb);
+               dev_err(dev, "Cannot verify MAC address, error reading: %d\n",
+                       result);
+               goto error;
+       }
+       /* Extract MAC address */
+       ddi = (void *) skb->data;
+       BUILD_BUG_ON(ETH_ALEN != sizeof(ddi->mac_address));
+       d_printf(2, dev, "GET DEVICE INFO: mac addr %pM\n",
+                ddi->mac_address);
+       if (!memcmp(net_dev->perm_addr, ddi->mac_address,
+                  sizeof(ddi->mac_address)))
+               goto ok;
+       dev_warn(dev, "warning: device reports a different MAC address "
+                "to that of boot mode's\n");
+       dev_warn(dev, "device reports     %pM\n", ddi->mac_address);
+       dev_warn(dev, "boot mode reported %pM\n", net_dev->perm_addr);
+       if (is_zero_ether_addr(ddi->mac_address))
+               dev_err(dev, "device reports an invalid MAC address, "
+                       "not updating\n");
+       else {
+               dev_warn(dev, "updating MAC address\n");
+               net_dev->addr_len = ETH_ALEN;
+               memcpy(net_dev->perm_addr, ddi->mac_address, ETH_ALEN);
+               memcpy(net_dev->dev_addr, ddi->mac_address, ETH_ALEN);
+       }
+ok:
+       result = 0;
+       kfree_skb(skb);
+error:
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+}
+
+
+/**
+ * __i2400m_dev_start - Bring up driver communication with the device
+ *
+ * @i2400m: device descriptor
+ * @flags: boot mode flags
+ *
+ * Returns: 0 if ok, < 0 errno code on error.
+ *
+ * Uploads firmware and brings up all the resources needed to be able
+ * to communicate with the device.
+ *
+ * The workqueue has to be setup early, at least before RX handling
+ * (it's only real user for now) so it can process reports as they
+ * arrive. We also want to destroy it if we retry, to make sure it is
+ * flushed...easier like this.
+ *
+ * TX needs to be setup before the bus-specific code (otherwise on
+ * shutdown, the bus-tx code could try to access it).
+ */
+static
+int __i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri flags)
+{
+       int result;
+       struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
+       struct net_device *net_dev = wimax_dev->net_dev;
+       struct device *dev = i2400m_dev(i2400m);
+       int times = i2400m->bus_bm_retries;
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+retry:
+       result = i2400m_dev_bootstrap(i2400m, flags);
+       if (result < 0) {
+               dev_err(dev, "cannot bootstrap device: %d\n", result);
+               goto error_bootstrap;
+       }
+       result = i2400m_tx_setup(i2400m);
+       if (result < 0)
+               goto error_tx_setup;
+       result = i2400m_rx_setup(i2400m);
+       if (result < 0)
+               goto error_rx_setup;
+       i2400m->work_queue = create_singlethread_workqueue(wimax_dev->name);
+       if (i2400m->work_queue == NULL) {
+               result = -ENOMEM;
+               dev_err(dev, "cannot create workqueue\n");
+               goto error_create_workqueue;
+       }
+       if (i2400m->bus_dev_start) {
+               result = i2400m->bus_dev_start(i2400m);
+               if (result < 0)
+                       goto error_bus_dev_start;
+       }
+       i2400m->ready = 1;
+       wmb();          /* see i2400m->ready's documentation  */
+       /* process pending reports from the device */
+       queue_work(i2400m->work_queue, &i2400m->rx_report_ws);
+       result = i2400m_firmware_check(i2400m); /* fw versions ok? */
+       if (result < 0)
+               goto error_fw_check;
+       /* At this point is ok to send commands to the device */
+       result = i2400m_check_mac_addr(i2400m);
+       if (result < 0)
+               goto error_check_mac_addr;
+       result = i2400m_dev_initialize(i2400m);
+       if (result < 0)
+               goto error_dev_initialize;
+
+       /* We don't want any additional unwanted error recovery triggered
+        * from any other context so if anything went wrong before we come
+        * here, let's keep i2400m->error_recovery untouched and leave it to
+        * dev_reset_handle(). See dev_reset_handle(). */
+
+       atomic_dec(&i2400m->error_recovery);
+       /* Every thing works so far, ok, now we are ready to
+        * take error recovery if it's required. */
+
+       /* At this point, reports will come for the device and set it
+        * to the right state if it is different than UNINITIALIZED */
+       d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
+               net_dev, i2400m, result);
+       return result;
+
+error_dev_initialize:
+error_check_mac_addr:
+error_fw_check:
+       i2400m->ready = 0;
+       wmb();          /* see i2400m->ready's documentation  */
+       flush_workqueue(i2400m->work_queue);
+       if (i2400m->bus_dev_stop)
+               i2400m->bus_dev_stop(i2400m);
+error_bus_dev_start:
+       destroy_workqueue(i2400m->work_queue);
+error_create_workqueue:
+       i2400m_rx_release(i2400m);
+error_rx_setup:
+       i2400m_tx_release(i2400m);
+error_tx_setup:
+error_bootstrap:
+       if (result == -EL3RST && times-- > 0) {
+               flags = I2400M_BRI_SOFT|I2400M_BRI_MAC_REINIT;
+               goto retry;
+       }
+       d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
+               net_dev, i2400m, result);
+       return result;
+}
+
+
+static
+int i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri bm_flags)
+{
+       int result = 0;
+       mutex_lock(&i2400m->init_mutex);        /* Well, start the device */
+       if (i2400m->updown == 0) {
+               result = __i2400m_dev_start(i2400m, bm_flags);
+               if (result >= 0) {
+                       i2400m->updown = 1;
+                       i2400m->alive = 1;
+                       wmb();/* see i2400m->updown and i2400m->alive's doc */
+               }
+       }
+       mutex_unlock(&i2400m->init_mutex);
+       return result;
+}
+
+
+/**
+ * i2400m_dev_stop - Tear down driver communication with the device
+ *
+ * @i2400m: device descriptor
+ *
+ * Returns: 0 if ok, < 0 errno code on error.
+ *
+ * Releases all the resources allocated to communicate with the
+ * device. Note we cannot destroy the workqueue earlier as until RX is
+ * fully destroyed, it could still try to schedule jobs.
+ */
+static
+void __i2400m_dev_stop(struct i2400m *i2400m)
+{
+       struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
+       struct device *dev = i2400m_dev(i2400m);
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
+       i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
+       complete(&i2400m->msg_completion);
+       i2400m_net_wake_stop(i2400m);
+       i2400m_dev_shutdown(i2400m);
+       /*
+        * Make sure no report hooks are running *before* we stop the
+        * communication infrastructure with the device.
+        */
+       i2400m->ready = 0;      /* nobody can queue work anymore */
+       wmb();          /* see i2400m->ready's documentation  */
+       flush_workqueue(i2400m->work_queue);
+
+       if (i2400m->bus_dev_stop)
+               i2400m->bus_dev_stop(i2400m);
+       destroy_workqueue(i2400m->work_queue);
+       i2400m_rx_release(i2400m);
+       i2400m_tx_release(i2400m);
+       wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
+       d_fnend(3, dev, "(i2400m %p) = 0\n", i2400m);
+}
+
+
+/*
+ * Watch out -- we only need to stop if there is a need for it. The
+ * device could have reset itself and failed to come up again (see
+ * _i2400m_dev_reset_handle()).
+ */
+static
+void i2400m_dev_stop(struct i2400m *i2400m)
+{
+       mutex_lock(&i2400m->init_mutex);
+       if (i2400m->updown) {
+               __i2400m_dev_stop(i2400m);
+               i2400m->updown = 0;
+               i2400m->alive = 0;
+               wmb();  /* see i2400m->updown and i2400m->alive's doc */
+       }
+       mutex_unlock(&i2400m->init_mutex);
+}
+
+
+/*
+ * Listen to PM events to cache the firmware before suspend/hibernation
+ *
+ * When the device comes out of suspend, it might go into reset and
+ * firmware has to be uploaded again. At resume, most of the times, we
+ * can't load firmware images from disk, so we need to cache it.
+ *
+ * i2400m_fw_cache() will allocate a kobject and attach the firmware
+ * to it; that way we don't have to worry too much about the fw loader
+ * hitting a race condition.
+ *
+ * Note: modus operandi stolen from the Orinoco driver; thx.
+ */
+static
+int i2400m_pm_notifier(struct notifier_block *notifier,
+                      unsigned long pm_event,
+                      void *unused)
+{
+       struct i2400m *i2400m =
+               container_of(notifier, struct i2400m, pm_notifier);
+       struct device *dev = i2400m_dev(i2400m);
+
+       d_fnstart(3, dev, "(i2400m %p pm_event %lx)\n", i2400m, pm_event);
+       switch (pm_event) {
+       case PM_HIBERNATION_PREPARE:
+       case PM_SUSPEND_PREPARE:
+               i2400m_fw_cache(i2400m);
+               break;
+       case PM_POST_RESTORE:
+               /* Restore from hibernation failed. We need to clean
+                * up in exactly the same way, so fall through. */
+       case PM_POST_HIBERNATION:
+       case PM_POST_SUSPEND:
+               i2400m_fw_uncache(i2400m);
+               break;
+
+       case PM_RESTORE_PREPARE:
+       default:
+               break;
+       }
+       d_fnend(3, dev, "(i2400m %p pm_event %lx) = void\n", i2400m, pm_event);
+       return NOTIFY_DONE;
+}
+
+
+/*
+ * pre-reset is called before a device is going on reset
+ *
+ * This has to be followed by a call to i2400m_post_reset(), otherwise
+ * bad things might happen.
+ */
+int i2400m_pre_reset(struct i2400m *i2400m)
+{
+       struct device *dev = i2400m_dev(i2400m);
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       d_printf(1, dev, "pre-reset shut down\n");
+
+       mutex_lock(&i2400m->init_mutex);
+       if (i2400m->updown) {
+               netif_tx_disable(i2400m->wimax_dev.net_dev);
+               __i2400m_dev_stop(i2400m);
+               /* down't set updown to zero -- this way
+                * post_reset can restore properly */
+       }
+       mutex_unlock(&i2400m->init_mutex);
+       if (i2400m->bus_release)
+               i2400m->bus_release(i2400m);
+       d_fnend(3, dev, "(i2400m %p) = 0\n", i2400m);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(i2400m_pre_reset);
+
+
+/*
+ * Restore device state after a reset
+ *
+ * Do the work needed after a device reset to bring it up to the same
+ * state as it was before the reset.
+ *
+ * NOTE: this requires i2400m->init_mutex taken
+ */
+int i2400m_post_reset(struct i2400m *i2400m)
+{
+       int result = 0;
+       struct device *dev = i2400m_dev(i2400m);
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       d_printf(1, dev, "post-reset start\n");
+       if (i2400m->bus_setup) {
+               result = i2400m->bus_setup(i2400m);
+               if (result < 0) {
+                       dev_err(dev, "bus-specific setup failed: %d\n",
+                               result);
+                       goto error_bus_setup;
+               }
+       }
+       mutex_lock(&i2400m->init_mutex);
+       if (i2400m->updown) {
+               result = __i2400m_dev_start(
+                       i2400m, I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
+               if (result < 0)
+                       goto error_dev_start;
+       }
+       mutex_unlock(&i2400m->init_mutex);
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+
+error_dev_start:
+       if (i2400m->bus_release)
+               i2400m->bus_release(i2400m);
+       /* even if the device was up, it could not be recovered, so we
+        * mark it as down. */
+       i2400m->updown = 0;
+       wmb();          /* see i2400m->updown's documentation  */
+       mutex_unlock(&i2400m->init_mutex);
+error_bus_setup:
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+}
+EXPORT_SYMBOL_GPL(i2400m_post_reset);
+
+
+/*
+ * The device has rebooted; fix up the device and the driver
+ *
+ * Tear down the driver communication with the device, reload the
+ * firmware and reinitialize the communication with the device.
+ *
+ * If someone calls a reset when the device's firmware is down, in
+ * theory we won't see it because we are not listening. However, just
+ * in case, leave the code to handle it.
+ *
+ * If there is a reset context, use it; this means someone is waiting
+ * for us to tell him when the reset operation is complete and the
+ * device is ready to rock again.
+ *
+ * NOTE: if we are in the process of bringing up or down the
+ *       communication with the device [running i2400m_dev_start() or
+ *       _stop()], don't do anything, let it fail and handle it.
+ *
+ * This function is ran always in a thread context
+ *
+ * This function gets passed, as payload to i2400m_work() a 'const
+ * char *' ptr with a "reason" why the reset happened (for messages).
+ */
+static
+void __i2400m_dev_reset_handle(struct work_struct *ws)
+{
+       struct i2400m *i2400m = container_of(ws, struct i2400m, reset_ws);
+       const char *reason = i2400m->reset_reason;
+       struct device *dev = i2400m_dev(i2400m);
+       struct i2400m_reset_ctx *ctx = i2400m->reset_ctx;
+       int result;
+
+       d_fnstart(3, dev, "(ws %p i2400m %p reason %s)\n", ws, i2400m, reason);
+
+       i2400m->boot_mode = 1;
+       wmb();          /* Make sure i2400m_msg_to_dev() sees boot_mode */
+
+       result = 0;
+       if (mutex_trylock(&i2400m->init_mutex) == 0) {
+               /* We are still in i2400m_dev_start() [let it fail] or
+                * i2400m_dev_stop() [we are shutting down anyway, so
+                * ignore it] or we are resetting somewhere else. */
+               dev_err(dev, "device rebooted somewhere else?\n");
+               i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
+               complete(&i2400m->msg_completion);
+               goto out;
+       }
+
+       dev_err(dev, "%s: reinitializing driver\n", reason);
+       rmb();
+       if (i2400m->updown) {
+               __i2400m_dev_stop(i2400m);
+               i2400m->updown = 0;
+               wmb();          /* see i2400m->updown's documentation  */
+       }
+
+       if (i2400m->alive) {
+               result = __i2400m_dev_start(i2400m,
+                                   I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
+               if (result < 0) {
+                       dev_err(dev, "%s: cannot start the device: %d\n",
+                               reason, result);
+                       result = -EUCLEAN;
+                       if (atomic_read(&i2400m->bus_reset_retries)
+                                       >= I2400M_BUS_RESET_RETRIES) {
+                               result = -ENODEV;
+                               dev_err(dev, "tried too many times to "
+                                       "reset the device, giving up\n");
+                       }
+               }
+       }
+
+       if (i2400m->reset_ctx) {
+               ctx->result = result;
+               complete(&ctx->completion);
+       }
+       mutex_unlock(&i2400m->init_mutex);
+       if (result == -EUCLEAN) {
+               /*
+                * We come here because the reset during operational mode
+                * wasn't successfully done and need to proceed to a bus
+                * reset. For the dev_reset_handle() to be able to handle
+                * the reset event later properly, we restore boot_mode back
+                * to the state before previous reset. ie: just like we are
+                * issuing the bus reset for the first time
+                */
+               i2400m->boot_mode = 0;
+               wmb();
+
+               atomic_inc(&i2400m->bus_reset_retries);
+               /* ops, need to clean up [w/ init_mutex not held] */
+               result = i2400m_reset(i2400m, I2400M_RT_BUS);
+               if (result >= 0)
+                       result = -ENODEV;
+       } else {
+               rmb();
+               if (i2400m->alive) {
+                       /* great, we expect the device state up and
+                        * dev_start() actually brings the device state up */
+                       i2400m->updown = 1;
+                       wmb();
+                       atomic_set(&i2400m->bus_reset_retries, 0);
+               }
+       }
+out:
+       d_fnend(3, dev, "(ws %p i2400m %p reason %s) = void\n",
+               ws, i2400m, reason);
+}
+
+
+/**
+ * i2400m_dev_reset_handle - Handle a device's reset in a thread context
+ *
+ * Schedule a device reset handling out on a thread context, so it
+ * is safe to call from atomic context. We can't use the i2400m's
+ * queue as we are going to destroy it and reinitialize it as part of
+ * the driver bringup/bringup process.
+ *
+ * See __i2400m_dev_reset_handle() for details; that takes care of
+ * reinitializing the driver to handle the reset, calling into the
+ * bus-specific functions ops as needed.
+ */
+int i2400m_dev_reset_handle(struct i2400m *i2400m, const char *reason)
+{
+       i2400m->reset_reason = reason;
+       return schedule_work(&i2400m->reset_ws);
+}
+EXPORT_SYMBOL_GPL(i2400m_dev_reset_handle);
+
+
+ /*
+ * The actual work of error recovery.
+ *
+ * The current implementation of error recovery is to trigger a bus reset.
+ */
+static
+void __i2400m_error_recovery(struct work_struct *ws)
+{
+       struct i2400m *i2400m = container_of(ws, struct i2400m, recovery_ws);
+
+       i2400m_reset(i2400m, I2400M_RT_BUS);
+}
+
+/*
+ * Schedule a work struct for error recovery.
+ *
+ * The intention of error recovery is to bring back the device to some
+ * known state whenever TX sees -110 (-ETIMEOUT) on copying the data to
+ * the device. The TX failure could mean a device bus stuck, so the current
+ * error recovery implementation is to trigger a bus reset to the device
+ * and hopefully it can bring back the device.
+ *
+ * The actual work of error recovery has to be in a thread context because
+ * it is kicked off in the TX thread (i2400ms->tx_workqueue) which is to be
+ * destroyed by the error recovery mechanism (currently a bus reset).
+ *
+ * Also, there may be already a queue of TX works that all hit
+ * the -ETIMEOUT error condition because the device is stuck already.
+ * Since bus reset is used as the error recovery mechanism and we don't
+ * want consecutive bus resets simply because the multiple TX works
+ * in the queue all hit the same device erratum, the flag "error_recovery"
+ * is introduced for preventing unwanted consecutive bus resets.
+ *
+ * Error recovery shall only be invoked again if previous one was completed.
+ * The flag error_recovery is set when error recovery mechanism is scheduled,
+ * and is checked when we need to schedule another error recovery. If it is
+ * in place already, then we shouldn't schedule another one.
+ */
+void i2400m_error_recovery(struct i2400m *i2400m)
+{
+       if (atomic_add_return(1, &i2400m->error_recovery) == 1)
+               schedule_work(&i2400m->recovery_ws);
+       else
+               atomic_dec(&i2400m->error_recovery);
+}
+EXPORT_SYMBOL_GPL(i2400m_error_recovery);
+
+/*
+ * Alloc the command and ack buffers for boot mode
+ *
+ * Get the buffers needed to deal with boot mode messages.
+ */
+static
+int i2400m_bm_buf_alloc(struct i2400m *i2400m)
+{
+       int result;
+
+       result = -ENOMEM;
+       i2400m->bm_cmd_buf = kzalloc(I2400M_BM_CMD_BUF_SIZE, GFP_KERNEL);
+       if (i2400m->bm_cmd_buf == NULL)
+               goto error_bm_cmd_kzalloc;
+       i2400m->bm_ack_buf = kzalloc(I2400M_BM_ACK_BUF_SIZE, GFP_KERNEL);
+       if (i2400m->bm_ack_buf == NULL)
+               goto error_bm_ack_buf_kzalloc;
+       return 0;
+
+error_bm_ack_buf_kzalloc:
+       kfree(i2400m->bm_cmd_buf);
+error_bm_cmd_kzalloc:
+       return result;
+}
+
+
+/*
+ * Free boot mode command and ack buffers.
+ */
+static
+void i2400m_bm_buf_free(struct i2400m *i2400m)
+{
+       kfree(i2400m->bm_ack_buf);
+       kfree(i2400m->bm_cmd_buf);
+}
+
+
+/**
+ * i2400m_init - Initialize a 'struct i2400m' from all zeroes
+ *
+ * This is a bus-generic API call.
+ */
+void i2400m_init(struct i2400m *i2400m)
+{
+       wimax_dev_init(&i2400m->wimax_dev);
+
+       i2400m->boot_mode = 1;
+       i2400m->rx_reorder = 1;
+       init_waitqueue_head(&i2400m->state_wq);
+
+       spin_lock_init(&i2400m->tx_lock);
+       i2400m->tx_pl_min = UINT_MAX;
+       i2400m->tx_size_min = UINT_MAX;
+
+       spin_lock_init(&i2400m->rx_lock);
+       i2400m->rx_pl_min = UINT_MAX;
+       i2400m->rx_size_min = UINT_MAX;
+       INIT_LIST_HEAD(&i2400m->rx_reports);
+       INIT_WORK(&i2400m->rx_report_ws, i2400m_report_hook_work);
+
+       mutex_init(&i2400m->msg_mutex);
+       init_completion(&i2400m->msg_completion);
+
+       mutex_init(&i2400m->init_mutex);
+       /* wake_tx_ws is initialized in i2400m_tx_setup() */
+
+       INIT_WORK(&i2400m->reset_ws, __i2400m_dev_reset_handle);
+       INIT_WORK(&i2400m->recovery_ws, __i2400m_error_recovery);
+
+       atomic_set(&i2400m->bus_reset_retries, 0);
+
+       i2400m->alive = 0;
+
+       /* initialize error_recovery to 1 for denoting we
+        * are not yet ready to take any error recovery */
+       atomic_set(&i2400m->error_recovery, 1);
+}
+EXPORT_SYMBOL_GPL(i2400m_init);
+
+
+int i2400m_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
+{
+       struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+
+       /*
+        * Make sure we stop TXs and down the carrier before
+        * resetting; this is needed to avoid things like
+        * i2400m_wake_tx() scheduling stuff in parallel.
+        */
+       if (net_dev->reg_state == NETREG_REGISTERED) {
+               netif_tx_disable(net_dev);
+               netif_carrier_off(net_dev);
+       }
+       return i2400m->bus_reset(i2400m, rt);
+}
+EXPORT_SYMBOL_GPL(i2400m_reset);
+
+
+/**
+ * i2400m_setup - bus-generic setup function for the i2400m device
+ *
+ * @i2400m: device descriptor (bus-specific parts have been initialized)
+ *
+ * Returns: 0 if ok, < 0 errno code on error.
+ *
+ * Sets up basic device comunication infrastructure, boots the ROM to
+ * read the MAC address, registers with the WiMAX and network stacks
+ * and then brings up the device.
+ */
+int i2400m_setup(struct i2400m *i2400m, enum i2400m_bri bm_flags)
+{
+       int result = -ENODEV;
+       struct device *dev = i2400m_dev(i2400m);
+       struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
+       struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+
+       snprintf(wimax_dev->name, sizeof(wimax_dev->name),
+                "i2400m-%s:%s", dev->bus->name, dev_name(dev));
+
+       result = i2400m_bm_buf_alloc(i2400m);
+       if (result < 0) {
+               dev_err(dev, "cannot allocate bootmode scratch buffers\n");
+               goto error_bm_buf_alloc;
+       }
+
+       if (i2400m->bus_setup) {
+               result = i2400m->bus_setup(i2400m);
+               if (result < 0) {
+                       dev_err(dev, "bus-specific setup failed: %d\n",
+                               result);
+                       goto error_bus_setup;
+               }
+       }
+
+       result = i2400m_bootrom_init(i2400m, bm_flags);
+       if (result < 0) {
+               dev_err(dev, "read mac addr: bootrom init "
+                       "failed: %d\n", result);
+               goto error_bootrom_init;
+       }
+       result = i2400m_read_mac_addr(i2400m);
+       if (result < 0)
+               goto error_read_mac_addr;
+       eth_random_addr(i2400m->src_mac_addr);
+
+       i2400m->pm_notifier.notifier_call = i2400m_pm_notifier;
+       register_pm_notifier(&i2400m->pm_notifier);
+
+       result = register_netdev(net_dev);      /* Okey dokey, bring it up */
+       if (result < 0) {
+               dev_err(dev, "cannot register i2400m network device: %d\n",
+                       result);
+               goto error_register_netdev;
+       }
+       netif_carrier_off(net_dev);
+
+       i2400m->wimax_dev.op_msg_from_user = i2400m_op_msg_from_user;
+       i2400m->wimax_dev.op_rfkill_sw_toggle = i2400m_op_rfkill_sw_toggle;
+       i2400m->wimax_dev.op_reset = i2400m_op_reset;
+
+       result = wimax_dev_add(&i2400m->wimax_dev, net_dev);
+       if (result < 0)
+               goto error_wimax_dev_add;
+
+       /* Now setup all that requires a registered net and wimax device. */
+       result = sysfs_create_group(&net_dev->dev.kobj, &i2400m_dev_attr_group);
+       if (result < 0) {
+               dev_err(dev, "cannot setup i2400m's sysfs: %d\n", result);
+               goto error_sysfs_setup;
+       }
+
+       result = i2400m_debugfs_add(i2400m);
+       if (result < 0) {
+               dev_err(dev, "cannot setup i2400m's debugfs: %d\n", result);
+               goto error_debugfs_setup;
+       }
+
+       result = i2400m_dev_start(i2400m, bm_flags);
+       if (result < 0)
+               goto error_dev_start;
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+
+error_dev_start:
+       i2400m_debugfs_rm(i2400m);
+error_debugfs_setup:
+       sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
+                          &i2400m_dev_attr_group);
+error_sysfs_setup:
+       wimax_dev_rm(&i2400m->wimax_dev);
+error_wimax_dev_add:
+       unregister_netdev(net_dev);
+error_register_netdev:
+       unregister_pm_notifier(&i2400m->pm_notifier);
+error_read_mac_addr:
+error_bootrom_init:
+       if (i2400m->bus_release)
+               i2400m->bus_release(i2400m);
+error_bus_setup:
+       i2400m_bm_buf_free(i2400m);
+error_bm_buf_alloc:
+       d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+       return result;
+}
+EXPORT_SYMBOL_GPL(i2400m_setup);
+
+
+/**
+ * i2400m_release - release the bus-generic driver resources
+ *
+ * Sends a disconnect message and undoes any setup done by i2400m_setup()
+ */
+void i2400m_release(struct i2400m *i2400m)
+{
+       struct device *dev = i2400m_dev(i2400m);
+
+       d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+       netif_stop_queue(i2400m->wimax_dev.net_dev);
+
+       i2400m_dev_stop(i2400m);
+
+       cancel_work_sync(&i2400m->reset_ws);
+       cancel_work_sync(&i2400m->recovery_ws);
+
+       i2400m_debugfs_rm(i2400m);
+       sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
+                          &i2400m_dev_attr_group);
+       wimax_dev_rm(&i2400m->wimax_dev);
+       unregister_netdev(i2400m->wimax_dev.net_dev);
+       unregister_pm_notifier(&i2400m->pm_notifier);
+       if (i2400m->bus_release)
+               i2400m->bus_release(i2400m);
+       i2400m_bm_buf_free(i2400m);
+       d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+}
+EXPORT_SYMBOL_GPL(i2400m_release);
+
+
+/*
+ * Debug levels control; see debug.h
+ */
+struct d_level D_LEVEL[] = {
+       D_SUBMODULE_DEFINE(control),
+       D_SUBMODULE_DEFINE(driver),
+       D_SUBMODULE_DEFINE(debugfs),
+       D_SUBMODULE_DEFINE(fw),
+       D_SUBMODULE_DEFINE(netdev),
+       D_SUBMODULE_DEFINE(rfkill),
+       D_SUBMODULE_DEFINE(rx),
+       D_SUBMODULE_DEFINE(sysfs),
+       D_SUBMODULE_DEFINE(tx),
+};
+size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
+
+
+static
+int __init i2400m_driver_init(void)
+{
+       d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400m_debug_params,
+                      "i2400m.debug");
+       return i2400m_barker_db_init(i2400m_barkers_params);
+}
+module_init(i2400m_driver_init);
+
+static
+void __exit i2400m_driver_exit(void)
+{
+       i2400m_barker_db_exit();
+}
+module_exit(i2400m_driver_exit);
+
+MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
+MODULE_DESCRIPTION("Intel 2400M WiMAX networking bus-generic driver");
+MODULE_LICENSE("GPL");