1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel Wireless WiMAX Connection 2400m
4 * Generic probe/disconnect, reset and message passing
5 *
6 * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * See i2400m.h for driver documentation. This contains helpers for
10 * the driver model glue [_setup()/_release()], handling device resets
11 * [_dev_reset_handle()], and the backends for the WiMAX stack ops
12 * reset [_op_reset()] and message from user [_op_msg_from_user()].
13 *
14 * ROADMAP:
15 *
16 * i2400m_op_msg_from_user()
17 *   i2400m_msg_to_dev()
18 *   wimax_msg_to_user_send()
19 *
20 * i2400m_op_reset()
21 *   i240m->bus_reset()
22 *
23 * i2400m_dev_reset_handle()
24 *   __i2400m_dev_reset_handle()
25 *     __i2400m_dev_stop()
26 *     __i2400m_dev_start()
27 *
28 * i2400m_setup()
29 *   i2400m->bus_setup()
30 *   i2400m_bootrom_init()
31 *   register_netdev()
32 *   wimax_dev_add()
33 *   i2400m_dev_start()
34 *     __i2400m_dev_start()
35 *       i2400m_dev_bootstrap()
36 *       i2400m_tx_setup()
37 *       i2400m->bus_dev_start()
38 *       i2400m_firmware_check()
39 *       i2400m_check_mac_addr()
40 *
41 * i2400m_release()
42 *   i2400m_dev_stop()
43 *     __i2400m_dev_stop()
44 *       i2400m_dev_shutdown()
45 *       i2400m->bus_dev_stop()
46 *       i2400m_tx_release()
47 *   i2400m->bus_release()
48 *   wimax_dev_rm()
49 *   unregister_netdev()
50 */
51#include "i2400m.h"
52#include <linux/etherdevice.h>
53#include <linux/wimax/i2400m.h>
54#include <linux/module.h>
55#include <linux/moduleparam.h>
56#include <linux/suspend.h>
57#include <linux/slab.h>
58
59#define D_SUBMODULE driver
60#include "debug-levels.h"
61
62
63static char i2400m_debug_params[128];
64module_param_string(debug, i2400m_debug_params, sizeof(i2400m_debug_params),
65		    0644);
66MODULE_PARM_DESC(debug,
67		 "String of space-separated NAME:VALUE pairs, where NAMEs "
68		 "are the different debug submodules and VALUE are the "
69		 "initial debug value to set.");
70
71static char i2400m_barkers_params[128];
72module_param_string(barkers, i2400m_barkers_params,
73		    sizeof(i2400m_barkers_params), 0644);
74MODULE_PARM_DESC(barkers,
75		 "String of comma-separated 32-bit values; each is "
76		 "recognized as the value the device sends as a reboot "
77		 "signal; values are appended to a list--setting one value "
78		 "as zero cleans the existing list and starts a new one.");
79
80/*
81 * WiMAX stack operation: relay a message from user space
82 *
83 * @wimax_dev: device descriptor
84 * @pipe_name: named pipe the message is for
85 * @msg_buf: pointer to the message bytes
86 * @msg_len: length of the buffer
87 * @genl_info: passed by the generic netlink layer
88 *
89 * The WiMAX stack will call this function when a message was received
90 * from user space.
91 *
92 * For the i2400m, this is an L3L4 message, as specified in
93 * include/linux/wimax/i2400m.h, and thus prefixed with a 'struct
94 * i2400m_l3l4_hdr'. Driver (and device) expect the messages to be
95 * coded in Little Endian.
96 *
97 * This function just verifies that the header declaration and the
98 * payload are consistent and then deals with it, either forwarding it
99 * to the device or procesing it locally.
100 *
101 * In the i2400m, messages are basically commands that will carry an
102 * ack, so we use i2400m_msg_to_dev() and then deliver the ack back to
103 * user space. The rx.c code might intercept the response and use it
104 * to update the driver's state, but then it will pass it on so it can
105 * be relayed back to user space.
106 *
107 * Note that asynchronous events from the device are processed and
108 * sent to user space in rx.c.
109 */
110static
111int i2400m_op_msg_from_user(struct wimax_dev *wimax_dev,
112			    const char *pipe_name,
113			    const void *msg_buf, size_t msg_len,
114			    const struct genl_info *genl_info)
115{
116	int result;
117	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
118	struct device *dev = i2400m_dev(i2400m);
119	struct sk_buff *ack_skb;
120
121	d_fnstart(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p "
122		  "msg_len %zu genl_info %p)\n", wimax_dev, i2400m,
123		  msg_buf, msg_len, genl_info);
124	ack_skb = i2400m_msg_to_dev(i2400m, msg_buf, msg_len);
125	result = PTR_ERR(ack_skb);
126	if (IS_ERR(ack_skb))
127		goto error_msg_to_dev;
128	result = wimax_msg_send(&i2400m->wimax_dev, ack_skb);
129error_msg_to_dev:
130	d_fnend(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p msg_len %zu "
131		"genl_info %p) = %d\n", wimax_dev, i2400m, msg_buf, msg_len,
132		genl_info, result);
133	return result;
134}
135
136
137/*
138 * Context to wait for a reset to finalize
139 */
140struct i2400m_reset_ctx {
141	struct completion completion;
142	int result;
143};
144
145
146/*
147 * WiMAX stack operation: reset a device
148 *
149 * @wimax_dev: device descriptor
150 *
151 * See the documentation for wimax_reset() and wimax_dev->op_reset for
152 * the requirements of this function. The WiMAX stack guarantees
153 * serialization on calls to this function.
154 *
155 * Do a warm reset on the device; if it fails, resort to a cold reset
156 * and return -ENODEV. On successful warm reset, we need to block
157 * until it is complete.
158 *
159 * The bus-driver implementation of reset takes care of falling back
160 * to cold reset if warm fails.
161 */
162static
163int i2400m_op_reset(struct wimax_dev *wimax_dev)
164{
165	int result;
166	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
167	struct device *dev = i2400m_dev(i2400m);
168	struct i2400m_reset_ctx ctx = {
169		.completion = COMPLETION_INITIALIZER_ONSTACK(ctx.completion),
170		.result = 0,
171	};
172
173	d_fnstart(4, dev, "(wimax_dev %p)\n", wimax_dev);
174	mutex_lock(&i2400m->init_mutex);
175	i2400m->reset_ctx = &ctx;
176	mutex_unlock(&i2400m->init_mutex);
177	result = i2400m_reset(i2400m, I2400M_RT_WARM);
178	if (result < 0)
179		goto out;
180	result = wait_for_completion_timeout(&ctx.completion, 4*HZ);
181	if (result == 0)
182		result = -ETIMEDOUT;
183	else if (result > 0)
184		result = ctx.result;
185	/* if result < 0, pass it on */
186	mutex_lock(&i2400m->init_mutex);
187	i2400m->reset_ctx = NULL;
188	mutex_unlock(&i2400m->init_mutex);
189out:
190	d_fnend(4, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
191	return result;
192}
193
194
195/*
196 * Check the MAC address we got from boot mode is ok
197 *
198 * @i2400m: device descriptor
199 *
200 * Returns: 0 if ok, < 0 errno code on error.
201 */
202static
203int i2400m_check_mac_addr(struct i2400m *i2400m)
204{
205	int result;
206	struct device *dev = i2400m_dev(i2400m);
207	struct sk_buff *skb;
208	const struct i2400m_tlv_detailed_device_info *ddi;
209	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
210
211	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
212	skb = i2400m_get_device_info(i2400m);
213	if (IS_ERR(skb)) {
214		result = PTR_ERR(skb);
215		dev_err(dev, "Cannot verify MAC address, error reading: %d\n",
216			result);
217		goto error;
218	}
219	/* Extract MAC address */
220	ddi = (void *) skb->data;
221	BUILD_BUG_ON(ETH_ALEN != sizeof(ddi->mac_address));
222	d_printf(2, dev, "GET DEVICE INFO: mac addr %pM\n",
223		 ddi->mac_address);
224	if (!memcmp(net_dev->perm_addr, ddi->mac_address,
225		   sizeof(ddi->mac_address)))
226		goto ok;
227	dev_warn(dev, "warning: device reports a different MAC address "
228		 "to that of boot mode's\n");
229	dev_warn(dev, "device reports     %pM\n", ddi->mac_address);
230	dev_warn(dev, "boot mode reported %pM\n", net_dev->perm_addr);
231	if (is_zero_ether_addr(ddi->mac_address))
232		dev_err(dev, "device reports an invalid MAC address, "
233			"not updating\n");
234	else {
235		dev_warn(dev, "updating MAC address\n");
236		net_dev->addr_len = ETH_ALEN;
237		memcpy(net_dev->perm_addr, ddi->mac_address, ETH_ALEN);
238		memcpy(net_dev->dev_addr, ddi->mac_address, ETH_ALEN);
239	}
240ok:
241	result = 0;
242	kfree_skb(skb);
243error:
244	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
245	return result;
246}
247
248
249/**
250 * __i2400m_dev_start - Bring up driver communication with the device
251 *
252 * @i2400m: device descriptor
253 * @flags: boot mode flags
254 *
255 * Returns: 0 if ok, < 0 errno code on error.
256 *
257 * Uploads firmware and brings up all the resources needed to be able
258 * to communicate with the device.
259 *
260 * The workqueue has to be setup early, at least before RX handling
261 * (it's only real user for now) so it can process reports as they
262 * arrive. We also want to destroy it if we retry, to make sure it is
263 * flushed...easier like this.
264 *
265 * TX needs to be setup before the bus-specific code (otherwise on
266 * shutdown, the bus-tx code could try to access it).
267 */
268static
269int __i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri flags)
270{
271	int result;
272	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
273	struct net_device *net_dev = wimax_dev->net_dev;
274	struct device *dev = i2400m_dev(i2400m);
275	int times = i2400m->bus_bm_retries;
276
277	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
278retry:
279	result = i2400m_dev_bootstrap(i2400m, flags);
280	if (result < 0) {
281		dev_err(dev, "cannot bootstrap device: %d\n", result);
282		goto error_bootstrap;
283	}
284	result = i2400m_tx_setup(i2400m);
285	if (result < 0)
286		goto error_tx_setup;
287	result = i2400m_rx_setup(i2400m);
288	if (result < 0)
289		goto error_rx_setup;
290	i2400m->work_queue = create_singlethread_workqueue(wimax_dev->name);
291	if (i2400m->work_queue == NULL) {
292		result = -ENOMEM;
293		dev_err(dev, "cannot create workqueue\n");
294		goto error_create_workqueue;
295	}
296	if (i2400m->bus_dev_start) {
297		result = i2400m->bus_dev_start(i2400m);
298		if (result < 0)
299			goto error_bus_dev_start;
300	}
301	i2400m->ready = 1;
302	wmb();		/* see i2400m->ready's documentation  */
303	/* process pending reports from the device */
304	queue_work(i2400m->work_queue, &i2400m->rx_report_ws);
305	result = i2400m_firmware_check(i2400m);	/* fw versions ok? */
306	if (result < 0)
307		goto error_fw_check;
308	/* At this point is ok to send commands to the device */
309	result = i2400m_check_mac_addr(i2400m);
310	if (result < 0)
311		goto error_check_mac_addr;
312	result = i2400m_dev_initialize(i2400m);
313	if (result < 0)
314		goto error_dev_initialize;
315
316	/* We don't want any additional unwanted error recovery triggered
317	 * from any other context so if anything went wrong before we come
318	 * here, let's keep i2400m->error_recovery untouched and leave it to
319	 * dev_reset_handle(). See dev_reset_handle(). */
320
321	atomic_dec(&i2400m->error_recovery);
322	/* Every thing works so far, ok, now we are ready to
323	 * take error recovery if it's required. */
324
325	/* At this point, reports will come for the device and set it
326	 * to the right state if it is different than UNINITIALIZED */
327	d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
328		net_dev, i2400m, result);
329	return result;
330
331error_dev_initialize:
332error_check_mac_addr:
333error_fw_check:
334	i2400m->ready = 0;
335	wmb();		/* see i2400m->ready's documentation  */
336	flush_workqueue(i2400m->work_queue);
337	if (i2400m->bus_dev_stop)
338		i2400m->bus_dev_stop(i2400m);
339error_bus_dev_start:
340	destroy_workqueue(i2400m->work_queue);
341error_create_workqueue:
342	i2400m_rx_release(i2400m);
343error_rx_setup:
344	i2400m_tx_release(i2400m);
345error_tx_setup:
346error_bootstrap:
347	if (result == -EL3RST && times-- > 0) {
348		flags = I2400M_BRI_SOFT|I2400M_BRI_MAC_REINIT;
349		goto retry;
350	}
351	d_fnend(3, dev, "(net_dev %p [i2400m %p]) = %d\n",
352		net_dev, i2400m, result);
353	return result;
354}
355
356
357static
358int i2400m_dev_start(struct i2400m *i2400m, enum i2400m_bri bm_flags)
359{
360	int result = 0;
361	mutex_lock(&i2400m->init_mutex);	/* Well, start the device */
362	if (i2400m->updown == 0) {
363		result = __i2400m_dev_start(i2400m, bm_flags);
364		if (result >= 0) {
365			i2400m->updown = 1;
366			i2400m->alive = 1;
367			wmb();/* see i2400m->updown and i2400m->alive's doc */
368		}
369	}
370	mutex_unlock(&i2400m->init_mutex);
371	return result;
372}
373
374
375/**
376 * i2400m_dev_stop - Tear down driver communication with the device
377 *
378 * @i2400m: device descriptor
379 *
380 * Returns: 0 if ok, < 0 errno code on error.
381 *
382 * Releases all the resources allocated to communicate with the
383 * device. Note we cannot destroy the workqueue earlier as until RX is
384 * fully destroyed, it could still try to schedule jobs.
385 */
386static
387void __i2400m_dev_stop(struct i2400m *i2400m)
388{
389	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
390	struct device *dev = i2400m_dev(i2400m);
391
392	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
393	wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
394	i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
395	complete(&i2400m->msg_completion);
396	i2400m_net_wake_stop(i2400m);
397	i2400m_dev_shutdown(i2400m);
398	/*
399	 * Make sure no report hooks are running *before* we stop the
400	 * communication infrastructure with the device.
401	 */
402	i2400m->ready = 0;	/* nobody can queue work anymore */
403	wmb();		/* see i2400m->ready's documentation  */
404	flush_workqueue(i2400m->work_queue);
405
406	if (i2400m->bus_dev_stop)
407		i2400m->bus_dev_stop(i2400m);
408	destroy_workqueue(i2400m->work_queue);
409	i2400m_rx_release(i2400m);
410	i2400m_tx_release(i2400m);
411	wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
412	d_fnend(3, dev, "(i2400m %p) = 0\n", i2400m);
413}
414
415
416/*
417 * Watch out -- we only need to stop if there is a need for it. The
418 * device could have reset itself and failed to come up again (see
419 * _i2400m_dev_reset_handle()).
420 */
421static
422void i2400m_dev_stop(struct i2400m *i2400m)
423{
424	mutex_lock(&i2400m->init_mutex);
425	if (i2400m->updown) {
426		__i2400m_dev_stop(i2400m);
427		i2400m->updown = 0;
428		i2400m->alive = 0;
429		wmb();	/* see i2400m->updown and i2400m->alive's doc */
430	}
431	mutex_unlock(&i2400m->init_mutex);
432}
433
434
435/*
436 * Listen to PM events to cache the firmware before suspend/hibernation
437 *
438 * When the device comes out of suspend, it might go into reset and
439 * firmware has to be uploaded again. At resume, most of the times, we
440 * can't load firmware images from disk, so we need to cache it.
441 *
442 * i2400m_fw_cache() will allocate a kobject and attach the firmware
443 * to it; that way we don't have to worry too much about the fw loader
444 * hitting a race condition.
445 *
446 * Note: modus operandi stolen from the Orinoco driver; thx.
447 */
448static
449int i2400m_pm_notifier(struct notifier_block *notifier,
450		       unsigned long pm_event,
451		       void *unused)
452{
453	struct i2400m *i2400m =
454		container_of(notifier, struct i2400m, pm_notifier);
455	struct device *dev = i2400m_dev(i2400m);
456
457	d_fnstart(3, dev, "(i2400m %p pm_event %lx)\n", i2400m, pm_event);
458	switch (pm_event) {
459	case PM_HIBERNATION_PREPARE:
460	case PM_SUSPEND_PREPARE:
461		i2400m_fw_cache(i2400m);
462		break;
463	case PM_POST_RESTORE:
464		/* Restore from hibernation failed. We need to clean
465		 * up in exactly the same way, so fall through. */
466	case PM_POST_HIBERNATION:
467	case PM_POST_SUSPEND:
468		i2400m_fw_uncache(i2400m);
469		break;
470
471	case PM_RESTORE_PREPARE:
472	default:
473		break;
474	}
475	d_fnend(3, dev, "(i2400m %p pm_event %lx) = void\n", i2400m, pm_event);
476	return NOTIFY_DONE;
477}
478
479
480/*
481 * pre-reset is called before a device is going on reset
482 *
483 * This has to be followed by a call to i2400m_post_reset(), otherwise
484 * bad things might happen.
485 */
486int i2400m_pre_reset(struct i2400m *i2400m)
487{
488	struct device *dev = i2400m_dev(i2400m);
489
490	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
491	d_printf(1, dev, "pre-reset shut down\n");
492
493	mutex_lock(&i2400m->init_mutex);
494	if (i2400m->updown) {
495		netif_tx_disable(i2400m->wimax_dev.net_dev);
496		__i2400m_dev_stop(i2400m);
497		/* down't set updown to zero -- this way
498		 * post_reset can restore properly */
499	}
500	mutex_unlock(&i2400m->init_mutex);
501	if (i2400m->bus_release)
502		i2400m->bus_release(i2400m);
503	d_fnend(3, dev, "(i2400m %p) = 0\n", i2400m);
504	return 0;
505}
506EXPORT_SYMBOL_GPL(i2400m_pre_reset);
507
508
509/*
510 * Restore device state after a reset
511 *
512 * Do the work needed after a device reset to bring it up to the same
513 * state as it was before the reset.
514 *
515 * NOTE: this requires i2400m->init_mutex taken
516 */
517int i2400m_post_reset(struct i2400m *i2400m)
518{
519	int result = 0;
520	struct device *dev = i2400m_dev(i2400m);
521
522	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
523	d_printf(1, dev, "post-reset start\n");
524	if (i2400m->bus_setup) {
525		result = i2400m->bus_setup(i2400m);
526		if (result < 0) {
527			dev_err(dev, "bus-specific setup failed: %d\n",
528				result);
529			goto error_bus_setup;
530		}
531	}
532	mutex_lock(&i2400m->init_mutex);
533	if (i2400m->updown) {
534		result = __i2400m_dev_start(
535			i2400m, I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
536		if (result < 0)
537			goto error_dev_start;
538	}
539	mutex_unlock(&i2400m->init_mutex);
540	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
541	return result;
542
543error_dev_start:
544	if (i2400m->bus_release)
545		i2400m->bus_release(i2400m);
546	/* even if the device was up, it could not be recovered, so we
547	 * mark it as down. */
548	i2400m->updown = 0;
549	wmb();		/* see i2400m->updown's documentation  */
550	mutex_unlock(&i2400m->init_mutex);
551error_bus_setup:
552	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
553	return result;
554}
555EXPORT_SYMBOL_GPL(i2400m_post_reset);
556
557
558/*
559 * The device has rebooted; fix up the device and the driver
560 *
561 * Tear down the driver communication with the device, reload the
562 * firmware and reinitialize the communication with the device.
563 *
564 * If someone calls a reset when the device's firmware is down, in
565 * theory we won't see it because we are not listening. However, just
566 * in case, leave the code to handle it.
567 *
568 * If there is a reset context, use it; this means someone is waiting
569 * for us to tell him when the reset operation is complete and the
570 * device is ready to rock again.
571 *
572 * NOTE: if we are in the process of bringing up or down the
573 *       communication with the device [running i2400m_dev_start() or
574 *       _stop()], don't do anything, let it fail and handle it.
575 *
576 * This function is ran always in a thread context
577 *
578 * This function gets passed, as payload to i2400m_work() a 'const
579 * char *' ptr with a "reason" why the reset happened (for messages).
580 */
581static
582void __i2400m_dev_reset_handle(struct work_struct *ws)
583{
584	struct i2400m *i2400m = container_of(ws, struct i2400m, reset_ws);
585	const char *reason = i2400m->reset_reason;
586	struct device *dev = i2400m_dev(i2400m);
587	struct i2400m_reset_ctx *ctx = i2400m->reset_ctx;
588	int result;
589
590	d_fnstart(3, dev, "(ws %p i2400m %p reason %s)\n", ws, i2400m, reason);
591
592	i2400m->boot_mode = 1;
593	wmb();		/* Make sure i2400m_msg_to_dev() sees boot_mode */
594
595	result = 0;
596	if (mutex_trylock(&i2400m->init_mutex) == 0) {
597		/* We are still in i2400m_dev_start() [let it fail] or
598		 * i2400m_dev_stop() [we are shutting down anyway, so
599		 * ignore it] or we are resetting somewhere else. */
600		dev_err(dev, "device rebooted somewhere else?\n");
601		i2400m_msg_to_dev_cancel_wait(i2400m, -EL3RST);
602		complete(&i2400m->msg_completion);
603		goto out;
604	}
605
606	dev_err(dev, "%s: reinitializing driver\n", reason);
607	rmb();
608	if (i2400m->updown) {
609		__i2400m_dev_stop(i2400m);
610		i2400m->updown = 0;
611		wmb();		/* see i2400m->updown's documentation  */
612	}
613
614	if (i2400m->alive) {
615		result = __i2400m_dev_start(i2400m,
616				    I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);
617		if (result < 0) {
618			dev_err(dev, "%s: cannot start the device: %d\n",
619				reason, result);
620			result = -EUCLEAN;
621			if (atomic_read(&i2400m->bus_reset_retries)
622					>= I2400M_BUS_RESET_RETRIES) {
623				result = -ENODEV;
624				dev_err(dev, "tried too many times to "
625					"reset the device, giving up\n");
626			}
627		}
628	}
629
630	if (i2400m->reset_ctx) {
631		ctx->result = result;
632		complete(&ctx->completion);
633	}
634	mutex_unlock(&i2400m->init_mutex);
635	if (result == -EUCLEAN) {
636		/*
637		 * We come here because the reset during operational mode
638		 * wasn't successfully done and need to proceed to a bus
639		 * reset. For the dev_reset_handle() to be able to handle
640		 * the reset event later properly, we restore boot_mode back
641		 * to the state before previous reset. ie: just like we are
642		 * issuing the bus reset for the first time
643		 */
644		i2400m->boot_mode = 0;
645		wmb();
646
647		atomic_inc(&i2400m->bus_reset_retries);
648		/* ops, need to clean up [w/ init_mutex not held] */
649		result = i2400m_reset(i2400m, I2400M_RT_BUS);
650		if (result >= 0)
651			result = -ENODEV;
652	} else {
653		rmb();
654		if (i2400m->alive) {
655			/* great, we expect the device state up and
656			 * dev_start() actually brings the device state up */
657			i2400m->updown = 1;
658			wmb();
659			atomic_set(&i2400m->bus_reset_retries, 0);
660		}
661	}
662out:
663	d_fnend(3, dev, "(ws %p i2400m %p reason %s) = void\n",
664		ws, i2400m, reason);
665}
666
667
668/**
669 * i2400m_dev_reset_handle - Handle a device's reset in a thread context
670 *
671 * Schedule a device reset handling out on a thread context, so it
672 * is safe to call from atomic context. We can't use the i2400m's
673 * queue as we are going to destroy it and reinitialize it as part of
674 * the driver bringup/bringup process.
675 *
676 * See __i2400m_dev_reset_handle() for details; that takes care of
677 * reinitializing the driver to handle the reset, calling into the
678 * bus-specific functions ops as needed.
679 */
680int i2400m_dev_reset_handle(struct i2400m *i2400m, const char *reason)
681{
682	i2400m->reset_reason = reason;
683	return schedule_work(&i2400m->reset_ws);
684}
685EXPORT_SYMBOL_GPL(i2400m_dev_reset_handle);
686
687
688 /*
689 * The actual work of error recovery.
690 *
691 * The current implementation of error recovery is to trigger a bus reset.
692 */
693static
694void __i2400m_error_recovery(struct work_struct *ws)
695{
696	struct i2400m *i2400m = container_of(ws, struct i2400m, recovery_ws);
697
698	i2400m_reset(i2400m, I2400M_RT_BUS);
699}
700
701/*
702 * Schedule a work struct for error recovery.
703 *
704 * The intention of error recovery is to bring back the device to some
705 * known state whenever TX sees -110 (-ETIMEOUT) on copying the data to
706 * the device. The TX failure could mean a device bus stuck, so the current
707 * error recovery implementation is to trigger a bus reset to the device
708 * and hopefully it can bring back the device.
709 *
710 * The actual work of error recovery has to be in a thread context because
711 * it is kicked off in the TX thread (i2400ms->tx_workqueue) which is to be
712 * destroyed by the error recovery mechanism (currently a bus reset).
713 *
714 * Also, there may be already a queue of TX works that all hit
715 * the -ETIMEOUT error condition because the device is stuck already.
716 * Since bus reset is used as the error recovery mechanism and we don't
717 * want consecutive bus resets simply because the multiple TX works
718 * in the queue all hit the same device erratum, the flag "error_recovery"
719 * is introduced for preventing unwanted consecutive bus resets.
720 *
721 * Error recovery shall only be invoked again if previous one was completed.
722 * The flag error_recovery is set when error recovery mechanism is scheduled,
723 * and is checked when we need to schedule another error recovery. If it is
724 * in place already, then we shouldn't schedule another one.
725 */
726void i2400m_error_recovery(struct i2400m *i2400m)
727{
728	if (atomic_add_return(1, &i2400m->error_recovery) == 1)
729		schedule_work(&i2400m->recovery_ws);
730	else
731		atomic_dec(&i2400m->error_recovery);
732}
733EXPORT_SYMBOL_GPL(i2400m_error_recovery);
734
735/*
736 * Alloc the command and ack buffers for boot mode
737 *
738 * Get the buffers needed to deal with boot mode messages.
739 */
740static
741int i2400m_bm_buf_alloc(struct i2400m *i2400m)
742{
743	i2400m->bm_cmd_buf = kzalloc(I2400M_BM_CMD_BUF_SIZE, GFP_KERNEL);
744	if (i2400m->bm_cmd_buf == NULL)
745		goto error_bm_cmd_kzalloc;
746	i2400m->bm_ack_buf = kzalloc(I2400M_BM_ACK_BUF_SIZE, GFP_KERNEL);
747	if (i2400m->bm_ack_buf == NULL)
748		goto error_bm_ack_buf_kzalloc;
749	return 0;
750
751error_bm_ack_buf_kzalloc:
752	kfree(i2400m->bm_cmd_buf);
753error_bm_cmd_kzalloc:
754	return -ENOMEM;
755}
756
757
758/*
759 * Free boot mode command and ack buffers.
760 */
761static
762void i2400m_bm_buf_free(struct i2400m *i2400m)
763{
764	kfree(i2400m->bm_ack_buf);
765	kfree(i2400m->bm_cmd_buf);
766}
767
768
769/**
770 * i2400m_init - Initialize a 'struct i2400m' from all zeroes
771 *
772 * This is a bus-generic API call.
773 */
774void i2400m_init(struct i2400m *i2400m)
775{
776	wimax_dev_init(&i2400m->wimax_dev);
777
778	i2400m->boot_mode = 1;
779	i2400m->rx_reorder = 1;
780	init_waitqueue_head(&i2400m->state_wq);
781
782	spin_lock_init(&i2400m->tx_lock);
783	i2400m->tx_pl_min = UINT_MAX;
784	i2400m->tx_size_min = UINT_MAX;
785
786	spin_lock_init(&i2400m->rx_lock);
787	i2400m->rx_pl_min = UINT_MAX;
788	i2400m->rx_size_min = UINT_MAX;
789	INIT_LIST_HEAD(&i2400m->rx_reports);
790	INIT_WORK(&i2400m->rx_report_ws, i2400m_report_hook_work);
791
792	mutex_init(&i2400m->msg_mutex);
793	init_completion(&i2400m->msg_completion);
794
795	mutex_init(&i2400m->init_mutex);
796	/* wake_tx_ws is initialized in i2400m_tx_setup() */
797
798	INIT_WORK(&i2400m->reset_ws, __i2400m_dev_reset_handle);
799	INIT_WORK(&i2400m->recovery_ws, __i2400m_error_recovery);
800
801	atomic_set(&i2400m->bus_reset_retries, 0);
802
803	i2400m->alive = 0;
804
805	/* initialize error_recovery to 1 for denoting we
806	 * are not yet ready to take any error recovery */
807	atomic_set(&i2400m->error_recovery, 1);
808}
809EXPORT_SYMBOL_GPL(i2400m_init);
810
811
812int i2400m_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
813{
814	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
815
816	/*
817	 * Make sure we stop TXs and down the carrier before
818	 * resetting; this is needed to avoid things like
819	 * i2400m_wake_tx() scheduling stuff in parallel.
820	 */
821	if (net_dev->reg_state == NETREG_REGISTERED) {
822		netif_tx_disable(net_dev);
823		netif_carrier_off(net_dev);
824	}
825	return i2400m->bus_reset(i2400m, rt);
826}
827EXPORT_SYMBOL_GPL(i2400m_reset);
828
829
830/**
831 * i2400m_setup - bus-generic setup function for the i2400m device
832 *
833 * @i2400m: device descriptor (bus-specific parts have been initialized)
834 *
835 * Returns: 0 if ok, < 0 errno code on error.
836 *
837 * Sets up basic device comunication infrastructure, boots the ROM to
838 * read the MAC address, registers with the WiMAX and network stacks
839 * and then brings up the device.
840 */
841int i2400m_setup(struct i2400m *i2400m, enum i2400m_bri bm_flags)
842{
843	int result;
844	struct device *dev = i2400m_dev(i2400m);
845	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
846	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
847
848	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
849
850	snprintf(wimax_dev->name, sizeof(wimax_dev->name),
851		 "i2400m-%s:%s", dev->bus->name, dev_name(dev));
852
853	result = i2400m_bm_buf_alloc(i2400m);
854	if (result < 0) {
855		dev_err(dev, "cannot allocate bootmode scratch buffers\n");
856		goto error_bm_buf_alloc;
857	}
858
859	if (i2400m->bus_setup) {
860		result = i2400m->bus_setup(i2400m);
861		if (result < 0) {
862			dev_err(dev, "bus-specific setup failed: %d\n",
863				result);
864			goto error_bus_setup;
865		}
866	}
867
868	result = i2400m_bootrom_init(i2400m, bm_flags);
869	if (result < 0) {
870		dev_err(dev, "read mac addr: bootrom init "
871			"failed: %d\n", result);
872		goto error_bootrom_init;
873	}
874	result = i2400m_read_mac_addr(i2400m);
875	if (result < 0)
876		goto error_read_mac_addr;
877	eth_random_addr(i2400m->src_mac_addr);
878
879	i2400m->pm_notifier.notifier_call = i2400m_pm_notifier;
880	register_pm_notifier(&i2400m->pm_notifier);
881
882	result = register_netdev(net_dev);	/* Okey dokey, bring it up */
883	if (result < 0) {
884		dev_err(dev, "cannot register i2400m network device: %d\n",
885			result);
886		goto error_register_netdev;
887	}
888	netif_carrier_off(net_dev);
889
890	i2400m->wimax_dev.op_msg_from_user = i2400m_op_msg_from_user;
891	i2400m->wimax_dev.op_rfkill_sw_toggle = i2400m_op_rfkill_sw_toggle;
892	i2400m->wimax_dev.op_reset = i2400m_op_reset;
893
894	result = wimax_dev_add(&i2400m->wimax_dev, net_dev);
895	if (result < 0)
896		goto error_wimax_dev_add;
897
898	/* Now setup all that requires a registered net and wimax device. */
899	result = sysfs_create_group(&net_dev->dev.kobj, &i2400m_dev_attr_group);
900	if (result < 0) {
901		dev_err(dev, "cannot setup i2400m's sysfs: %d\n", result);
902		goto error_sysfs_setup;
903	}
904
905	i2400m_debugfs_add(i2400m);
906
907	result = i2400m_dev_start(i2400m, bm_flags);
908	if (result < 0)
909		goto error_dev_start;
910	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
911	return result;
912
913error_dev_start:
914	i2400m_debugfs_rm(i2400m);
915	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
916			   &i2400m_dev_attr_group);
917error_sysfs_setup:
918	wimax_dev_rm(&i2400m->wimax_dev);
919error_wimax_dev_add:
920	unregister_netdev(net_dev);
921error_register_netdev:
922	unregister_pm_notifier(&i2400m->pm_notifier);
923error_read_mac_addr:
924error_bootrom_init:
925	if (i2400m->bus_release)
926		i2400m->bus_release(i2400m);
927error_bus_setup:
928	i2400m_bm_buf_free(i2400m);
929error_bm_buf_alloc:
930	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
931	return result;
932}
933EXPORT_SYMBOL_GPL(i2400m_setup);
934
935
936/**
937 * i2400m_release - release the bus-generic driver resources
938 *
939 * Sends a disconnect message and undoes any setup done by i2400m_setup()
940 */
941void i2400m_release(struct i2400m *i2400m)
942{
943	struct device *dev = i2400m_dev(i2400m);
944
945	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
946	netif_stop_queue(i2400m->wimax_dev.net_dev);
947
948	i2400m_dev_stop(i2400m);
949
950	cancel_work_sync(&i2400m->reset_ws);
951	cancel_work_sync(&i2400m->recovery_ws);
952
953	i2400m_debugfs_rm(i2400m);
954	sysfs_remove_group(&i2400m->wimax_dev.net_dev->dev.kobj,
955			   &i2400m_dev_attr_group);
956	wimax_dev_rm(&i2400m->wimax_dev);
957	unregister_netdev(i2400m->wimax_dev.net_dev);
958	unregister_pm_notifier(&i2400m->pm_notifier);
959	if (i2400m->bus_release)
960		i2400m->bus_release(i2400m);
961	i2400m_bm_buf_free(i2400m);
962	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
963}
964EXPORT_SYMBOL_GPL(i2400m_release);
965
966
967/*
968 * Debug levels control; see debug.h
969 */
970struct d_level D_LEVEL[] = {
971	D_SUBMODULE_DEFINE(control),
972	D_SUBMODULE_DEFINE(driver),
973	D_SUBMODULE_DEFINE(debugfs),
974	D_SUBMODULE_DEFINE(fw),
975	D_SUBMODULE_DEFINE(netdev),
976	D_SUBMODULE_DEFINE(rfkill),
977	D_SUBMODULE_DEFINE(rx),
978	D_SUBMODULE_DEFINE(sysfs),
979	D_SUBMODULE_DEFINE(tx),
980};
981size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
982
983
984static
985int __init i2400m_driver_init(void)
986{
987	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400m_debug_params,
988		       "i2400m.debug");
989	return i2400m_barker_db_init(i2400m_barkers_params);
990}
991module_init(i2400m_driver_init);
992
993static
994void __exit i2400m_driver_exit(void)
995{
996	i2400m_barker_db_exit();
997}
998module_exit(i2400m_driver_exit);
999
1000MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
1001MODULE_DESCRIPTION("Intel 2400M WiMAX networking bus-generic driver");
1002MODULE_LICENSE("GPL");
1003