driver.c

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/*
 * Intel Wireless WiMAX Connection 2400m
 * Generic probe/disconnect, reset and message passing
 *
 *
 * Copyright (C) 2007-2008 Intel Corporation <[email protected]>
 * Inaky Perez-Gonzalez <[email protected]>
 *
 * 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;
}


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;
}


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)
{
    int result;
    struct device *dev = i2400m_dev(i2400m);

    d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
    d_printf(1, dev, "pre-reset shut down\n");

    result = 0;
    mutex_lock(&i2400m->init_mutex);
    if (i2400m->updown) {
        netif_tx_disable(i2400m->wimax_dev.net_dev);
        __i2400m_dev_stop(i2400m);
        result = 0;
        /* 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) = %d\n", i2400m, result);
    return result;
}
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);
}


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);
}


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);


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);


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 <[email protected]>");
MODULE_DESCRIPTION("Intel 2400M WiMAX networking bus-generic driver");
MODULE_LICENSE("GPL");