driver.c 31.2 KB
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/*
 * 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()
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 *   i2400m->bus_setup()
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 *   i2400m_bootrom_init()
 *   register_netdev()
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 *   wimax_dev_add()
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 *   i2400m_dev_start()
 *     __i2400m_dev_start()
 *       i2400m_dev_bootstrap()
 *       i2400m_tx_setup()
 *       i2400m->bus_dev_start()
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 *       i2400m_firmware_check()
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 *       i2400m_check_mac_addr()
 *
 * i2400m_release()
 *   i2400m_dev_stop()
 *     __i2400m_dev_stop()
 *       i2400m_dev_shutdown()
 *       i2400m->bus_dev_stop()
 *       i2400m_tx_release()
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 *   i2400m->bus_release()
 *   wimax_dev_rm()
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 *   unregister_netdev()
 */
#include "i2400m.h"
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#include <linux/etherdevice.h>
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#include <linux/wimax/i2400m.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
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#include <linux/suspend.h>
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#include <linux/slab.h>
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#define D_SUBMODULE driver
#include "debug-levels.h"


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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.");

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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.");

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static
struct i2400m_work *__i2400m_work_setup(
	struct i2400m *i2400m, void (*fn)(struct work_struct *),
	gfp_t gfp_flags, const void *pl, size_t pl_size)
{
	struct i2400m_work *iw;

	iw = kzalloc(sizeof(*iw) + pl_size, gfp_flags);
	if (iw == NULL)
		return NULL;
	iw->i2400m = i2400m_get(i2400m);
	iw->pl_size = pl_size;
	memcpy(iw->pl, pl, pl_size);
	INIT_WORK(&iw->ws, fn);
	return iw;
}


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/*
 * Schedule i2400m's specific work on the system's queue.
 *
 * Used for a few cases where we really need it; otherwise, identical
 * to i2400m_queue_work().
 *
 * Returns < 0 errno code on error, 1 if ok.
 *
 * If it returns zero, something really bad happened, as it means the
 * works struct was already queued, but we have just allocated it, so
 * it should not happen.
 */
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static int i2400m_schedule_work(struct i2400m *i2400m,
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			 void (*fn)(struct work_struct *), gfp_t gfp_flags,
			 const void *pl, size_t pl_size)
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{
	int result;
	struct i2400m_work *iw;

	result = -ENOMEM;
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	iw = __i2400m_work_setup(i2400m, fn, gfp_flags, pl, pl_size);
	if (iw != NULL) {
		result = schedule_work(&iw->ws);
		if (WARN_ON(result == 0))
			result = -ENXIO;
	}
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	return result;
}


/*
 * 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);
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	result = i2400m_reset(i2400m, I2400M_RT_WARM);
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	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;
	const unsigned char zeromac[ETH_ALEN] = { 0 };

	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 addresss */
	ddi = (void *) skb->data;
	BUILD_BUG_ON(ETH_ALEN != sizeof(ddi->mac_address));
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	d_printf(2, dev, "GET DEVICE INFO: mac addr %pM\n",
		 ddi->mac_address);
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	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");
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	dev_warn(dev, "device reports     %pM\n", ddi->mac_address);
	dev_warn(dev, "boot mode reported %pM\n", net_dev->perm_addr);
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	if (!memcmp(zeromac, ddi->mac_address, sizeof(zeromac)))
		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.
 *
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 * 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.
 *
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 * 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);
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	int times = i2400m->bus_bm_retries;
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	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;
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	result = i2400m_rx_setup(i2400m);
	if (result < 0)
		goto error_rx_setup;
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	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;
	}
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	if (i2400m->bus_dev_start) {
		result = i2400m->bus_dev_start(i2400m);
		if (result < 0)
			goto error_bus_dev_start;
	}
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	i2400m->ready = 1;
	wmb();		/* see i2400m->ready's documentation  */
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	/* process pending reports from the device */
	queue_work(i2400m->work_queue, &i2400m->rx_report_ws);
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	result = i2400m_firmware_check(i2400m);	/* fw versions ok? */
	if (result < 0)
		goto error_fw_check;
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	/* 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;
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	/* 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. */

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	/* 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:
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error_fw_check:
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	i2400m->ready = 0;
	wmb();		/* see i2400m->ready's documentation  */
	flush_workqueue(i2400m->work_queue);
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	if (i2400m->bus_dev_stop)
		i2400m->bus_dev_stop(i2400m);
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error_bus_dev_start:
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	destroy_workqueue(i2400m->work_queue);
error_create_workqueue:
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	i2400m_rx_release(i2400m);
error_rx_setup:
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	i2400m_tx_release(i2400m);
error_tx_setup:
error_bootstrap:
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	if (result == -EL3RST && times-- > 0) {
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		flags = I2400M_BRI_SOFT|I2400M_BRI_MAC_REINIT;
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		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)
{
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	int result = 0;
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	mutex_lock(&i2400m->init_mutex);	/* Well, start the device */
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	if (i2400m->updown == 0) {
		result = __i2400m_dev_start(i2400m, bm_flags);
		if (result >= 0) {
			i2400m->updown = 1;
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			i2400m->alive = 1;
			wmb();/* see i2400m->updown and i2400m->alive's doc */
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		}
	}
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	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.
 *
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 * 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.
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 */
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);
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	i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
	complete(&i2400m->msg_completion);
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	i2400m_net_wake_stop(i2400m);
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	i2400m_dev_shutdown(i2400m);
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	/*
	 * 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);

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	if (i2400m->bus_dev_stop)
		i2400m->bus_dev_stop(i2400m);
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	destroy_workqueue(i2400m->work_queue);
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	i2400m_rx_release(i2400m);
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	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;
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		i2400m->alive = 0;
		wmb();	/* see i2400m->updown and i2400m->alive's doc */
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	}
	mutex_unlock(&i2400m->init_mutex);
}


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/*
 * 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;
}


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/*
 * 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);
618
error_bus_setup:
619 620 621 622 623 624
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;
}
EXPORT_SYMBOL_GPL(i2400m_post_reset);


625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
/*
 * 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
644 645 646
 *
 * This function gets passed, as payload to i2400m_work() a 'const
 * char *' ptr with a "reason" why the reset happened (for messages).
647 648 649 650 651 652
 */
static
void __i2400m_dev_reset_handle(struct work_struct *ws)
{
	int result;
	struct i2400m_work *iw = container_of(ws, struct i2400m_work, ws);
653
	const char *reason;
654 655 656 657
	struct i2400m *i2400m = iw->i2400m;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400m_reset_ctx *ctx = i2400m->reset_ctx;

658 659 660 661 662 663 664
	if (WARN_ON(iw->pl_size != sizeof(reason)))
		reason = "SW BUG: reason n/a";
	else
		memcpy(&reason, iw->pl, sizeof(reason));

	d_fnstart(3, dev, "(ws %p i2400m %p reason %s)\n", ws, i2400m, reason);

665 666 667
	i2400m->boot_mode = 1;
	wmb();		/* Make sure i2400m_msg_to_dev() sees boot_mode */

668 669 670 671 672
	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. */
673
		dev_err(dev, "device rebooted somewhere else?\n");
674
		i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
675 676 677
		complete(&i2400m->msg_completion);
		goto out;
	}
678

679
	dev_err(dev, "%s: reinitializing driver\n", reason);
680 681 682
	rmb();
	if (i2400m->updown) {
		__i2400m_dev_stop(i2400m);
683 684 685
		i2400m->updown = 0;
		wmb();		/* see i2400m->updown's documentation  */
	}
686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702

	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");
			}
		}
	}

703 704 705 706 707
	if (i2400m->reset_ctx) {
		ctx->result = result;
		complete(&ctx->completion);
	}
	mutex_unlock(&i2400m->init_mutex);
708
	if (result == -EUCLEAN) {
709 710 711 712 713 714 715 716 717 718 719 720
		/*
		 * We come here because the reset during operational mode
		 * wasn't successully 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);
721
		/* ops, need to clean up [w/ init_mutex not held] */
722
		result = i2400m_reset(i2400m, I2400M_RT_BUS);
723 724
		if (result >= 0)
			result = -ENODEV;
725 726 727 728 729 730 731 732 733
	} 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);
		}
734
	}
735 736 737
out:
	i2400m_put(i2400m);
	kfree(iw);
738 739
	d_fnend(3, dev, "(ws %p i2400m %p reason %s) = void\n",
		ws, i2400m, reason);
740 741 742 743 744 745 746 747 748 749 750 751 752 753 754
}


/**
 * 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.
 */
755
int i2400m_dev_reset_handle(struct i2400m *i2400m, const char *reason)
756 757
{
	return i2400m_schedule_work(i2400m, __i2400m_dev_reset_handle,
758
				    GFP_ATOMIC, &reason, sizeof(reason));
759 760 761 762
}
EXPORT_SYMBOL_GPL(i2400m_dev_reset_handle);


763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
 /*
 * 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_work *iw = container_of(ws, struct i2400m_work, ws);
	struct i2400m *i2400m = iw->i2400m;

	i2400m_reset(i2400m, I2400M_RT_BUS);

	i2400m_put(i2400m);
	kfree(iw);
	return;
}

/*
 * 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)
{
	struct device *dev = i2400m_dev(i2400m);

	if (atomic_add_return(1, &i2400m->error_recovery) == 1) {
		if (i2400m_schedule_work(i2400m, __i2400m_error_recovery,
			GFP_ATOMIC, NULL, 0) < 0) {
			dev_err(dev, "run out of memory for "
				"scheduling an error recovery ?\n");
			atomic_dec(&i2400m->error_recovery);
		}
	} else
		atomic_dec(&i2400m->error_recovery);
	return;
}
EXPORT_SYMBOL_GPL(i2400m_error_recovery);

823 824
/*
 * Alloc the command and ack buffers for boot mode
825 826 827 828
 *
 * Get the buffers needed to deal with boot mode messages.  These
 * buffers need to be allocated before the sdio recieve irq is setup.
 */
829
static
830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
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;
}

849 850 851

/*
 * Free boot mode command and ack buffers.
852
 */
853
static
854 855 856 857 858
void i2400m_bm_buf_free(struct i2400m *i2400m)
{
	kfree(i2400m->bm_ack_buf);
	kfree(i2400m->bm_cmd_buf);
}
859 860


861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880
/**
 * 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;
881 882
	INIT_LIST_HEAD(&i2400m->rx_reports);
	INIT_WORK(&i2400m->rx_report_ws, i2400m_report_hook_work);
883 884 885 886 887 888

	mutex_init(&i2400m->msg_mutex);
	init_completion(&i2400m->msg_completion);

	mutex_init(&i2400m->init_mutex);
	/* wake_tx_ws is initialized in i2400m_tx_setup() */
889 890 891
	atomic_set(&i2400m->bus_reset_retries, 0);

	i2400m->alive = 0;
892 893 894 895

	/* initialize error_recovery to 1 for denoting we
	 * are not yet ready to take any error recovery */
	atomic_set(&i2400m->error_recovery, 1);
896 897 898 899
}
EXPORT_SYMBOL_GPL(i2400m_init);


900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917
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);


918 919 920 921 922 923 924
/**
 * 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.
 *
925 926 927
 * 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.
928 929 930 931 932 933 934 935 936 937 938
 */
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),
939
		 "i2400m-%s:%s", dev->bus->name, dev_name(dev));
940

941 942 943 944 945 946
	result = i2400m_bm_buf_alloc(i2400m);
	if (result < 0) {
		dev_err(dev, "cannot allocate bootmode scratch buffers\n");
		goto error_bm_buf_alloc;
	}

947 948 949 950 951 952 953 954 955
	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;
		}
	}

956 957 958 959 960 961 962 963 964
	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;
965
	random_ether_addr(i2400m->src_mac_addr);
966

967 968 969
	i2400m->pm_notifier.notifier_call = i2400m_pm_notifier;
	register_pm_notifier(&i2400m->pm_notifier);

970 971 972 973 974 975 976 977 978 979 980
	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;
981

982 983 984 985 986
	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. */
987 988 989 990 991
	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;
	}
992

993 994 995 996 997
	result = i2400m_debugfs_add(i2400m);
	if (result < 0) {
		dev_err(dev, "cannot setup i2400m's debugfs: %d\n", result);
		goto error_debugfs_setup;
	}
998 999 1000 1001

	result = i2400m_dev_start(i2400m, bm_flags);
	if (result < 0)
		goto error_dev_start;
1002 1003 1004
	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
	return result;

1005 1006
error_dev_start:
	i2400m_debugfs_rm(i2400m);
1007
error_debugfs_setup:
1008 1009 1010
	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
			   &i2400m_dev_attr_group);
error_sysfs_setup:
1011 1012 1013 1014
	wimax_dev_rm(&i2400m->wimax_dev);
error_wimax_dev_add:
	unregister_netdev(net_dev);
error_register_netdev:
1015
	unregister_pm_notifier(&i2400m->pm_notifier);
1016 1017
error_read_mac_addr:
error_bootrom_init:
1018 1019 1020
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
error_bus_setup:
1021 1022
	i2400m_bm_buf_free(i2400m);
error_bm_buf_alloc:
1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040
	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);

1041 1042
	i2400m_dev_stop(i2400m);

1043
	i2400m_debugfs_rm(i2400m);
1044 1045
	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
			   &i2400m_dev_attr_group);
1046 1047
	wimax_dev_rm(&i2400m->wimax_dev);
	unregister_netdev(i2400m->wimax_dev.net_dev);
1048
	unregister_pm_notifier(&i2400m->pm_notifier);
1049 1050
	if (i2400m->bus_release)
		i2400m->bus_release(i2400m);
1051
	i2400m_bm_buf_free(i2400m);
1052 1053 1054 1055 1056
	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
}
EXPORT_SYMBOL_GPL(i2400m_release);


1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067
/*
 * 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),
1068
	D_SUBMODULE_DEFINE(sysfs),
1069 1070 1071 1072 1073
	D_SUBMODULE_DEFINE(tx),
};
size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);


1074 1075 1076
static
int __init i2400m_driver_init(void)
{
1077 1078
	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400m_debug_params,
		       "i2400m.debug");
1079
	return i2400m_barker_db_init(i2400m_barkers_params);
1080 1081 1082 1083 1084 1085 1086 1087
}
module_init(i2400m_driver_init);

static
void __exit i2400m_driver_exit(void)
{
	/* for scheds i2400m_dev_reset_handle() */
	flush_scheduled_work();
1088
	i2400m_barker_db_exit();
1089 1090 1091 1092 1093 1094
}
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");