summaryrefslogtreecommitdiffstats
path: root/drivers/misc/mei/init.c
blob: 9306219d5675442b186b0ab6381fdd246ad09e60 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>

#include <linux/mei.h>

#include "mei_dev.h"
#include "hbm.h"
#include "client.h"

const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
	switch (state) {
	MEI_DEV_STATE(INITIALIZING);
	MEI_DEV_STATE(INIT_CLIENTS);
	MEI_DEV_STATE(ENABLED);
	MEI_DEV_STATE(RESETTING);
	MEI_DEV_STATE(DISABLED);
	MEI_DEV_STATE(POWER_DOWN);
	MEI_DEV_STATE(POWER_UP);
	default:
		return "unknown";
	}
#undef MEI_DEV_STATE
}

const char *mei_pg_state_str(enum mei_pg_state state)
{
#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
	switch (state) {
	MEI_PG_STATE(OFF);
	MEI_PG_STATE(ON);
	default:
		return "unknown";
	}
#undef MEI_PG_STATE
}

/**
 * mei_fw_status2str - convert fw status registers to printable string
 *
 * @fw_status:  firmware status
 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
 *
 * Return: number of bytes written or -EINVAL if buffer is to small
 */
ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
			  char *buf, size_t len)
{
	ssize_t cnt = 0;
	int i;

	buf[0] = '\0';

	if (len < MEI_FW_STATUS_STR_SZ)
		return -EINVAL;

	for (i = 0; i < fw_status->count; i++)
		cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
				fw_status->status[i]);

	/* drop last space */
	buf[cnt] = '\0';
	return cnt;
}
EXPORT_SYMBOL_GPL(mei_fw_status2str);

/**
 * mei_cancel_work - Cancel mei background jobs
 *
 * @dev: the device structure
 */
void mei_cancel_work(struct mei_device *dev)
{
	cancel_work_sync(&dev->init_work);
	cancel_work_sync(&dev->reset_work);

	cancel_delayed_work(&dev->timer_work);
}
EXPORT_SYMBOL_GPL(mei_cancel_work);

/**
 * mei_reset - resets host and fw.
 *
 * @dev: the device structure
 *
 * Return: 0 on success or < 0 if the reset hasn't succeeded
 */
int mei_reset(struct mei_device *dev)
{
	enum mei_dev_state state = dev->dev_state;
	bool interrupts_enabled;
	int ret;

	if (state != MEI_DEV_INITIALIZING &&
	    state != MEI_DEV_DISABLED &&
	    state != MEI_DEV_POWER_DOWN &&
	    state != MEI_DEV_POWER_UP) {
		char fw_sts_str[MEI_FW_STATUS_STR_SZ];

		mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
		dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
			 mei_dev_state_str(state), fw_sts_str);
	}

	/* we're already in reset, cancel the init timer
	 * if the reset was called due the hbm protocol error
	 * we need to call it before hw start
	 * so the hbm watchdog won't kick in
	 */
	mei_hbm_idle(dev);

	/* enter reset flow */
	interrupts_enabled = state != MEI_DEV_POWER_DOWN;
	dev->dev_state = MEI_DEV_RESETTING;

	dev->reset_count++;
	if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
		dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
		dev->dev_state = MEI_DEV_DISABLED;
		return -ENODEV;
	}

	ret = mei_hw_reset(dev, interrupts_enabled);
	/* fall through and remove the sw state even if hw reset has failed */

	/* no need to clean up software state in case of power up */
	if (state != MEI_DEV_INITIALIZING &&
	    state != MEI_DEV_POWER_UP) {

		/* remove all waiting requests */
		mei_cl_all_write_clear(dev);

		mei_cl_all_disconnect(dev);

		/* wake up all readers and writers so they can be interrupted */
		mei_cl_all_wakeup(dev);

		/* remove entry if already in list */
		dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
		mei_cl_unlink(&dev->wd_cl);
		mei_cl_unlink(&dev->iamthif_cl);
		mei_amthif_reset_params(dev);
	}

	mei_hbm_reset(dev);

	dev->rd_msg_hdr = 0;
	dev->wd_pending = false;

	if (ret) {
		dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
		return ret;
	}

	if (state == MEI_DEV_POWER_DOWN) {
		dev_dbg(dev->dev, "powering down: end of reset\n");
		dev->dev_state = MEI_DEV_DISABLED;
		return 0;
	}

	ret = mei_hw_start(dev);
	if (ret) {
		dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
		return ret;
	}

	dev_dbg(dev->dev, "link is established start sending messages.\n");

	dev->dev_state = MEI_DEV_INIT_CLIENTS;
	ret = mei_hbm_start_req(dev);
	if (ret) {
		dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
		dev->dev_state = MEI_DEV_RESETTING;
		return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(mei_reset);

/**
 * mei_start - initializes host and fw to start work.
 *
 * @dev: the device structure
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_start(struct mei_device *dev)
{
	int ret;

	mutex_lock(&dev->device_lock);

	/* acknowledge interrupt and stop interrupts */
	mei_clear_interrupts(dev);

	mei_hw_config(dev);

	dev_dbg(dev->dev, "reset in start the mei device.\n");

	dev->reset_count = 0;
	do {
		dev->dev_state = MEI_DEV_INITIALIZING;
		ret = mei_reset(dev);

		if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
			dev_err(dev->dev, "reset failed ret = %d", ret);
			goto err;
		}
	} while (ret);

	/* we cannot start the device w/o hbm start message completed */
	if (dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "reset failed");
		goto err;
	}

	if (mei_hbm_start_wait(dev)) {
		dev_err(dev->dev, "HBM haven't started");
		goto err;
	}

	if (!mei_host_is_ready(dev)) {
		dev_err(dev->dev, "host is not ready.\n");
		goto err;
	}

	if (!mei_hw_is_ready(dev)) {
		dev_err(dev->dev, "ME is not ready.\n");
		goto err;
	}

	if (!mei_hbm_version_is_supported(dev)) {
		dev_dbg(dev->dev, "MEI start failed.\n");
		goto err;
	}

	dev_dbg(dev->dev, "link layer has been established.\n");

	mutex_unlock(&dev->device_lock);
	return 0;
err:
	dev_err(dev->dev, "link layer initialization failed.\n");
	dev->dev_state = MEI_DEV_DISABLED;
	mutex_unlock(&dev->device_lock);
	return -ENODEV;
}
EXPORT_SYMBOL_GPL(mei_start);

/**
 * mei_restart - restart device after suspend
 *
 * @dev: the device structure
 *
 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
 */
int mei_restart(struct mei_device *dev)
{
	int err;

	mutex_lock(&dev->device_lock);

	mei_clear_interrupts(dev);

	dev->dev_state = MEI_DEV_POWER_UP;
	dev->reset_count = 0;

	err = mei_reset(dev);

	mutex_unlock(&dev->device_lock);

	if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "device disabled = %d\n", err);
		return -ENODEV;
	}

	/* try to start again */
	if (err)
		schedule_work(&dev->reset_work);


	return 0;
}
EXPORT_SYMBOL_GPL(mei_restart);

static void mei_reset_work(struct work_struct *work)
{
	struct mei_device *dev =
		container_of(work, struct mei_device,  reset_work);
	int ret;

	mutex_lock(&dev->device_lock);

	ret = mei_reset(dev);

	mutex_unlock(&dev->device_lock);

	if (dev->dev_state == MEI_DEV_DISABLED) {
		dev_err(dev->dev, "device disabled = %d\n", ret);
		return;
	}

	/* retry reset in case of failure */
	if (ret)
		schedule_work(&dev->reset_work);
}

void mei_stop(struct mei_device *dev)
{
	dev_dbg(dev->dev, "stopping the device.\n");

	mei_cancel_work(dev);

	mei_nfc_host_exit(dev);

	mei_cl_bus_remove_devices(dev);

	mutex_lock(&dev->device_lock);

	mei_wd_stop(dev);

	dev->dev_state = MEI_DEV_POWER_DOWN;
	mei_reset(dev);

	mutex_unlock(&dev->device_lock);

	mei_watchdog_unregister(dev);
}
EXPORT_SYMBOL_GPL(mei_stop);

/**
 * mei_write_is_idle - check if the write queues are idle
 *
 * @dev: the device structure
 *
 * Return: true of there is no pending write
 */
bool mei_write_is_idle(struct mei_device *dev)
{
	bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
		list_empty(&dev->ctrl_wr_list.list) &&
		list_empty(&dev->write_list.list));

	dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%d write=%d\n",
		idle,
		mei_dev_state_str(dev->dev_state),
		list_empty(&dev->ctrl_wr_list.list),
		list_empty(&dev->write_list.list));

	return idle;
}
EXPORT_SYMBOL_GPL(mei_write_is_idle);

/**
 * mei_device_init  -- initialize mei_device structure
 *
 * @dev: the mei device
 * @device: the device structure
 * @hw_ops: hw operations
 */
void mei_device_init(struct mei_device *dev,
		     struct device *device,
		     const struct mei_hw_ops *hw_ops)
{
	/* setup our list array */
	INIT_LIST_HEAD(&dev->file_list);
	INIT_LIST_HEAD(&dev->device_list);
	INIT_LIST_HEAD(&dev->me_clients);
	mutex_init(&dev->device_lock);
	init_waitqueue_head(&dev->wait_hw_ready);
	init_waitqueue_head(&dev->wait_pg);
	init_waitqueue_head(&dev->wait_hbm_start);
	init_waitqueue_head(&dev->wait_stop_wd);
	dev->dev_state = MEI_DEV_INITIALIZING;
	dev->reset_count = 0;

	mei_io_list_init(&dev->read_list);
	mei_io_list_init(&dev->write_list);
	mei_io_list_init(&dev->write_waiting_list);
	mei_io_list_init(&dev->ctrl_wr_list);
	mei_io_list_init(&dev->ctrl_rd_list);

	INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
	INIT_WORK(&dev->init_work, mei_host_client_init);
	INIT_WORK(&dev->reset_work, mei_reset_work);

	INIT_LIST_HEAD(&dev->wd_cl.link);
	INIT_LIST_HEAD(&dev->iamthif_cl.link);
	mei_io_list_init(&dev->amthif_cmd_list);
	mei_io_list_init(&dev->amthif_rd_complete_list);

	bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
	dev->open_handle_count = 0;

	/*
	 * Reserving the first client ID
	 * 0: Reserved for MEI Bus Message communications
	 */
	bitmap_set(dev->host_clients_map, 0, 1);

	dev->pg_event = MEI_PG_EVENT_IDLE;
	dev->ops      = hw_ops;
	dev->dev      = device;
}
EXPORT_SYMBOL_GPL(mei_device_init);