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222818c3 TW |
1 | /* |
2 | * Intel Management Engine Interface (Intel MEI) Linux driver | |
3 | * Copyright (c) 2015, Intel Corporation. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/interrupt.h> | |
c9cf20ee | 18 | #include <linux/debugfs.h> |
7a23f80e | 19 | #include <linux/completion.h> |
222818c3 TW |
20 | #include <linux/watchdog.h> |
21 | ||
22 | #include <linux/uuid.h> | |
23 | #include <linux/mei_cl_bus.h> | |
24 | ||
25 | /* | |
26 | * iAMT Watchdog Device | |
27 | */ | |
28 | #define INTEL_AMT_WATCHDOG_ID "iamt_wdt" | |
29 | ||
30 | #define MEI_WDT_DEFAULT_TIMEOUT 120 /* seconds */ | |
31 | #define MEI_WDT_MIN_TIMEOUT 120 /* seconds */ | |
32 | #define MEI_WDT_MAX_TIMEOUT 65535 /* seconds */ | |
33 | ||
34 | /* Commands */ | |
35 | #define MEI_MANAGEMENT_CONTROL 0x02 | |
36 | ||
37 | /* MEI Management Control version number */ | |
38 | #define MEI_MC_VERSION_NUMBER 0x10 | |
39 | ||
40 | /* Sub Commands */ | |
41 | #define MEI_MC_START_WD_TIMER_REQ 0x13 | |
7a23f80e TW |
42 | #define MEI_MC_START_WD_TIMER_RES 0x83 |
43 | #define MEI_WDT_STATUS_SUCCESS 0 | |
44 | #define MEI_WDT_WDSTATE_NOT_REQUIRED 0x1 | |
222818c3 TW |
45 | #define MEI_MC_STOP_WD_TIMER_REQ 0x14 |
46 | ||
47 | /** | |
48 | * enum mei_wdt_state - internal watchdog state | |
49 | * | |
7a23f80e | 50 | * @MEI_WDT_PROBE: wd in probing stage |
222818c3 TW |
51 | * @MEI_WDT_IDLE: wd is idle and not opened |
52 | * @MEI_WDT_START: wd was opened, start was called | |
53 | * @MEI_WDT_RUNNING: wd is expecting keep alive pings | |
54 | * @MEI_WDT_STOPPING: wd is stopping and will move to IDLE | |
7a23f80e | 55 | * @MEI_WDT_NOT_REQUIRED: wd device is not required |
222818c3 TW |
56 | */ |
57 | enum mei_wdt_state { | |
7a23f80e | 58 | MEI_WDT_PROBE, |
222818c3 TW |
59 | MEI_WDT_IDLE, |
60 | MEI_WDT_START, | |
61 | MEI_WDT_RUNNING, | |
62 | MEI_WDT_STOPPING, | |
7a23f80e | 63 | MEI_WDT_NOT_REQUIRED, |
222818c3 TW |
64 | }; |
65 | ||
c9cf20ee TW |
66 | static const char *mei_wdt_state_str(enum mei_wdt_state state) |
67 | { | |
68 | switch (state) { | |
7a23f80e TW |
69 | case MEI_WDT_PROBE: |
70 | return "PROBE"; | |
c9cf20ee TW |
71 | case MEI_WDT_IDLE: |
72 | return "IDLE"; | |
73 | case MEI_WDT_START: | |
74 | return "START"; | |
75 | case MEI_WDT_RUNNING: | |
76 | return "RUNNING"; | |
77 | case MEI_WDT_STOPPING: | |
78 | return "STOPPING"; | |
7a23f80e TW |
79 | case MEI_WDT_NOT_REQUIRED: |
80 | return "NOT_REQUIRED"; | |
c9cf20ee TW |
81 | default: |
82 | return "unknown"; | |
83 | } | |
84 | } | |
c9cf20ee | 85 | |
222818c3 TW |
86 | /** |
87 | * struct mei_wdt - mei watchdog driver | |
88 | * @wdd: watchdog device | |
89 | * | |
90 | * @cldev: mei watchdog client device | |
91 | * @state: watchdog internal state | |
7a23f80e TW |
92 | * @resp_required: ping required response |
93 | * @response: ping response completion | |
94 | * @unregister: unregister worker | |
95 | * @reg_lock: watchdog device registration lock | |
222818c3 | 96 | * @timeout: watchdog current timeout |
c9cf20ee TW |
97 | * |
98 | * @dbgfs_dir: debugfs dir entry | |
222818c3 TW |
99 | */ |
100 | struct mei_wdt { | |
101 | struct watchdog_device wdd; | |
102 | ||
103 | struct mei_cl_device *cldev; | |
104 | enum mei_wdt_state state; | |
7a23f80e TW |
105 | bool resp_required; |
106 | struct completion response; | |
107 | struct work_struct unregister; | |
108 | struct mutex reg_lock; | |
222818c3 | 109 | u16 timeout; |
c9cf20ee TW |
110 | |
111 | #if IS_ENABLED(CONFIG_DEBUG_FS) | |
112 | struct dentry *dbgfs_dir; | |
113 | #endif /* CONFIG_DEBUG_FS */ | |
222818c3 TW |
114 | }; |
115 | ||
116 | /* | |
117 | * struct mei_mc_hdr - Management Control Command Header | |
118 | * | |
119 | * @command: Management Control (0x2) | |
120 | * @bytecount: Number of bytes in the message beyond this byte | |
121 | * @subcommand: Management Control Subcommand | |
122 | * @versionnumber: Management Control Version (0x10) | |
123 | */ | |
124 | struct mei_mc_hdr { | |
125 | u8 command; | |
126 | u8 bytecount; | |
127 | u8 subcommand; | |
128 | u8 versionnumber; | |
129 | }; | |
130 | ||
131 | /** | |
132 | * struct mei_wdt_start_request watchdog start/ping | |
133 | * | |
134 | * @hdr: Management Control Command Header | |
135 | * @timeout: timeout value | |
136 | * @reserved: reserved (legacy) | |
137 | */ | |
138 | struct mei_wdt_start_request { | |
139 | struct mei_mc_hdr hdr; | |
140 | u16 timeout; | |
141 | u8 reserved[17]; | |
142 | } __packed; | |
143 | ||
7a23f80e TW |
144 | /** |
145 | * struct mei_wdt_start_response watchdog start/ping response | |
146 | * | |
147 | * @hdr: Management Control Command Header | |
148 | * @status: operation status | |
149 | * @wdstate: watchdog status bit mask | |
150 | */ | |
151 | struct mei_wdt_start_response { | |
152 | struct mei_mc_hdr hdr; | |
153 | u8 status; | |
154 | u8 wdstate; | |
155 | } __packed; | |
156 | ||
222818c3 TW |
157 | /** |
158 | * struct mei_wdt_stop_request - watchdog stop | |
159 | * | |
160 | * @hdr: Management Control Command Header | |
161 | */ | |
162 | struct mei_wdt_stop_request { | |
163 | struct mei_mc_hdr hdr; | |
164 | } __packed; | |
165 | ||
166 | /** | |
167 | * mei_wdt_ping - send wd start/ping command | |
168 | * | |
169 | * @wdt: mei watchdog device | |
170 | * | |
171 | * Return: 0 on success, | |
172 | * negative errno code on failure | |
173 | */ | |
174 | static int mei_wdt_ping(struct mei_wdt *wdt) | |
175 | { | |
176 | struct mei_wdt_start_request req; | |
177 | const size_t req_len = sizeof(req); | |
178 | int ret; | |
179 | ||
180 | memset(&req, 0, req_len); | |
181 | req.hdr.command = MEI_MANAGEMENT_CONTROL; | |
182 | req.hdr.bytecount = req_len - offsetof(struct mei_mc_hdr, subcommand); | |
183 | req.hdr.subcommand = MEI_MC_START_WD_TIMER_REQ; | |
184 | req.hdr.versionnumber = MEI_MC_VERSION_NUMBER; | |
185 | req.timeout = wdt->timeout; | |
186 | ||
187 | ret = mei_cldev_send(wdt->cldev, (u8 *)&req, req_len); | |
188 | if (ret < 0) | |
189 | return ret; | |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | /** | |
195 | * mei_wdt_stop - send wd stop command | |
196 | * | |
197 | * @wdt: mei watchdog device | |
198 | * | |
199 | * Return: 0 on success, | |
200 | * negative errno code on failure | |
201 | */ | |
202 | static int mei_wdt_stop(struct mei_wdt *wdt) | |
203 | { | |
204 | struct mei_wdt_stop_request req; | |
205 | const size_t req_len = sizeof(req); | |
206 | int ret; | |
207 | ||
208 | memset(&req, 0, req_len); | |
209 | req.hdr.command = MEI_MANAGEMENT_CONTROL; | |
210 | req.hdr.bytecount = req_len - offsetof(struct mei_mc_hdr, subcommand); | |
211 | req.hdr.subcommand = MEI_MC_STOP_WD_TIMER_REQ; | |
212 | req.hdr.versionnumber = MEI_MC_VERSION_NUMBER; | |
213 | ||
214 | ret = mei_cldev_send(wdt->cldev, (u8 *)&req, req_len); | |
215 | if (ret < 0) | |
216 | return ret; | |
217 | ||
218 | return 0; | |
219 | } | |
220 | ||
221 | /** | |
222 | * mei_wdt_ops_start - wd start command from the watchdog core. | |
223 | * | |
224 | * @wdd: watchdog device | |
225 | * | |
226 | * Return: 0 on success or -ENODEV; | |
227 | */ | |
228 | static int mei_wdt_ops_start(struct watchdog_device *wdd) | |
229 | { | |
230 | struct mei_wdt *wdt = watchdog_get_drvdata(wdd); | |
231 | ||
232 | wdt->state = MEI_WDT_START; | |
233 | wdd->timeout = wdt->timeout; | |
234 | return 0; | |
235 | } | |
236 | ||
237 | /** | |
238 | * mei_wdt_ops_stop - wd stop command from the watchdog core. | |
239 | * | |
240 | * @wdd: watchdog device | |
241 | * | |
242 | * Return: 0 if success, negative errno code for failure | |
243 | */ | |
244 | static int mei_wdt_ops_stop(struct watchdog_device *wdd) | |
245 | { | |
246 | struct mei_wdt *wdt = watchdog_get_drvdata(wdd); | |
247 | int ret; | |
248 | ||
249 | if (wdt->state != MEI_WDT_RUNNING) | |
250 | return 0; | |
251 | ||
252 | wdt->state = MEI_WDT_STOPPING; | |
253 | ||
254 | ret = mei_wdt_stop(wdt); | |
255 | if (ret) | |
256 | return ret; | |
257 | ||
258 | wdt->state = MEI_WDT_IDLE; | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
263 | /** | |
264 | * mei_wdt_ops_ping - wd ping command from the watchdog core. | |
265 | * | |
266 | * @wdd: watchdog device | |
267 | * | |
268 | * Return: 0 if success, negative errno code on failure | |
269 | */ | |
270 | static int mei_wdt_ops_ping(struct watchdog_device *wdd) | |
271 | { | |
272 | struct mei_wdt *wdt = watchdog_get_drvdata(wdd); | |
273 | int ret; | |
274 | ||
275 | if (wdt->state != MEI_WDT_START && wdt->state != MEI_WDT_RUNNING) | |
276 | return 0; | |
277 | ||
7a23f80e TW |
278 | if (wdt->resp_required) |
279 | init_completion(&wdt->response); | |
280 | ||
281 | wdt->state = MEI_WDT_RUNNING; | |
222818c3 TW |
282 | ret = mei_wdt_ping(wdt); |
283 | if (ret) | |
284 | return ret; | |
285 | ||
7a23f80e TW |
286 | if (wdt->resp_required) |
287 | ret = wait_for_completion_killable(&wdt->response); | |
222818c3 | 288 | |
7a23f80e | 289 | return ret; |
222818c3 TW |
290 | } |
291 | ||
292 | /** | |
293 | * mei_wdt_ops_set_timeout - wd set timeout command from the watchdog core. | |
294 | * | |
295 | * @wdd: watchdog device | |
296 | * @timeout: timeout value to set | |
297 | * | |
298 | * Return: 0 if success, negative errno code for failure | |
299 | */ | |
300 | static int mei_wdt_ops_set_timeout(struct watchdog_device *wdd, | |
301 | unsigned int timeout) | |
302 | { | |
303 | ||
304 | struct mei_wdt *wdt = watchdog_get_drvdata(wdd); | |
305 | ||
306 | /* valid value is already checked by the caller */ | |
307 | wdt->timeout = timeout; | |
308 | wdd->timeout = timeout; | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | static const struct watchdog_ops wd_ops = { | |
314 | .owner = THIS_MODULE, | |
315 | .start = mei_wdt_ops_start, | |
316 | .stop = mei_wdt_ops_stop, | |
317 | .ping = mei_wdt_ops_ping, | |
318 | .set_timeout = mei_wdt_ops_set_timeout, | |
319 | }; | |
320 | ||
321 | /* not const as the firmware_version field need to be retrieved */ | |
322 | static struct watchdog_info wd_info = { | |
323 | .identity = INTEL_AMT_WATCHDOG_ID, | |
324 | .options = WDIOF_KEEPALIVEPING | | |
325 | WDIOF_SETTIMEOUT | | |
326 | WDIOF_ALARMONLY, | |
327 | }; | |
328 | ||
7a23f80e TW |
329 | /** |
330 | * __mei_wdt_is_registered - check if wdt is registered | |
331 | * | |
332 | * @wdt: mei watchdog device | |
333 | * | |
334 | * Return: true if the wdt is registered with the watchdog subsystem | |
335 | * Locking: should be called under wdt->reg_lock | |
336 | */ | |
337 | static inline bool __mei_wdt_is_registered(struct mei_wdt *wdt) | |
338 | { | |
339 | return !!watchdog_get_drvdata(&wdt->wdd); | |
340 | } | |
341 | ||
222818c3 TW |
342 | /** |
343 | * mei_wdt_unregister - unregister from the watchdog subsystem | |
344 | * | |
345 | * @wdt: mei watchdog device | |
346 | */ | |
347 | static void mei_wdt_unregister(struct mei_wdt *wdt) | |
348 | { | |
7a23f80e TW |
349 | mutex_lock(&wdt->reg_lock); |
350 | ||
351 | if (__mei_wdt_is_registered(wdt)) { | |
352 | watchdog_unregister_device(&wdt->wdd); | |
353 | watchdog_set_drvdata(&wdt->wdd, NULL); | |
354 | memset(&wdt->wdd, 0, sizeof(wdt->wdd)); | |
355 | } | |
356 | ||
357 | mutex_unlock(&wdt->reg_lock); | |
222818c3 TW |
358 | } |
359 | ||
360 | /** | |
361 | * mei_wdt_register - register with the watchdog subsystem | |
362 | * | |
363 | * @wdt: mei watchdog device | |
364 | * | |
365 | * Return: 0 if success, negative errno code for failure | |
366 | */ | |
367 | static int mei_wdt_register(struct mei_wdt *wdt) | |
368 | { | |
369 | struct device *dev; | |
370 | int ret; | |
371 | ||
372 | if (!wdt || !wdt->cldev) | |
373 | return -EINVAL; | |
374 | ||
375 | dev = &wdt->cldev->dev; | |
376 | ||
7a23f80e TW |
377 | mutex_lock(&wdt->reg_lock); |
378 | ||
379 | if (__mei_wdt_is_registered(wdt)) { | |
380 | ret = 0; | |
381 | goto out; | |
382 | } | |
383 | ||
222818c3 TW |
384 | wdt->wdd.info = &wd_info; |
385 | wdt->wdd.ops = &wd_ops; | |
386 | wdt->wdd.parent = dev; | |
387 | wdt->wdd.timeout = MEI_WDT_DEFAULT_TIMEOUT; | |
388 | wdt->wdd.min_timeout = MEI_WDT_MIN_TIMEOUT; | |
389 | wdt->wdd.max_timeout = MEI_WDT_MAX_TIMEOUT; | |
390 | ||
391 | watchdog_set_drvdata(&wdt->wdd, wdt); | |
392 | ret = watchdog_register_device(&wdt->wdd); | |
393 | if (ret) { | |
394 | dev_err(dev, "unable to register watchdog device = %d.\n", ret); | |
395 | watchdog_set_drvdata(&wdt->wdd, NULL); | |
396 | } | |
397 | ||
7a23f80e TW |
398 | wdt->state = MEI_WDT_IDLE; |
399 | ||
400 | out: | |
401 | mutex_unlock(&wdt->reg_lock); | |
222818c3 TW |
402 | return ret; |
403 | } | |
404 | ||
7a23f80e TW |
405 | static void mei_wdt_unregister_work(struct work_struct *work) |
406 | { | |
407 | struct mei_wdt *wdt = container_of(work, struct mei_wdt, unregister); | |
408 | ||
409 | mei_wdt_unregister(wdt); | |
410 | } | |
411 | ||
412 | /** | |
413 | * mei_wdt_event_rx - callback for data receive | |
414 | * | |
415 | * @cldev: bus device | |
416 | */ | |
417 | static void mei_wdt_event_rx(struct mei_cl_device *cldev) | |
418 | { | |
419 | struct mei_wdt *wdt = mei_cldev_get_drvdata(cldev); | |
420 | struct mei_wdt_start_response res; | |
421 | const size_t res_len = sizeof(res); | |
422 | int ret; | |
423 | ||
424 | ret = mei_cldev_recv(wdt->cldev, (u8 *)&res, res_len); | |
425 | if (ret < 0) { | |
426 | dev_err(&cldev->dev, "failure in recv %d\n", ret); | |
427 | return; | |
428 | } | |
429 | ||
430 | /* Empty response can be sent on stop */ | |
431 | if (ret == 0) | |
432 | return; | |
433 | ||
434 | if (ret < sizeof(struct mei_mc_hdr)) { | |
435 | dev_err(&cldev->dev, "recv small data %d\n", ret); | |
436 | return; | |
437 | } | |
438 | ||
439 | if (res.hdr.command != MEI_MANAGEMENT_CONTROL || | |
440 | res.hdr.versionnumber != MEI_MC_VERSION_NUMBER) { | |
441 | dev_err(&cldev->dev, "wrong command received\n"); | |
442 | return; | |
443 | } | |
444 | ||
445 | if (res.hdr.subcommand != MEI_MC_START_WD_TIMER_RES) { | |
446 | dev_warn(&cldev->dev, "unsupported command %d :%s[%d]\n", | |
447 | res.hdr.subcommand, | |
448 | mei_wdt_state_str(wdt->state), | |
449 | wdt->state); | |
450 | return; | |
451 | } | |
452 | ||
453 | /* Run the unregistration in a worker as this can be | |
454 | * run only after ping completion, otherwise the flow will | |
455 | * deadlock on watchdog core mutex. | |
456 | */ | |
457 | if (wdt->state == MEI_WDT_RUNNING) { | |
458 | if (res.wdstate & MEI_WDT_WDSTATE_NOT_REQUIRED) { | |
459 | wdt->state = MEI_WDT_NOT_REQUIRED; | |
460 | schedule_work(&wdt->unregister); | |
461 | } | |
462 | goto out; | |
463 | } | |
464 | ||
465 | if (wdt->state == MEI_WDT_PROBE) { | |
466 | if (res.wdstate & MEI_WDT_WDSTATE_NOT_REQUIRED) { | |
467 | wdt->state = MEI_WDT_NOT_REQUIRED; | |
468 | } else { | |
469 | /* stop the watchdog and register watchdog device */ | |
470 | mei_wdt_stop(wdt); | |
471 | mei_wdt_register(wdt); | |
472 | } | |
473 | return; | |
474 | } | |
475 | ||
476 | dev_warn(&cldev->dev, "not in correct state %s[%d]\n", | |
477 | mei_wdt_state_str(wdt->state), wdt->state); | |
478 | ||
479 | out: | |
480 | if (!completion_done(&wdt->response)) | |
481 | complete(&wdt->response); | |
482 | } | |
483 | ||
3a20a5c3 TW |
484 | /* |
485 | * mei_wdt_notify_event - callback for event notification | |
486 | * | |
487 | * @cldev: bus device | |
488 | */ | |
489 | static void mei_wdt_notify_event(struct mei_cl_device *cldev) | |
490 | { | |
491 | struct mei_wdt *wdt = mei_cldev_get_drvdata(cldev); | |
492 | ||
493 | if (wdt->state != MEI_WDT_NOT_REQUIRED) | |
494 | return; | |
495 | ||
496 | mei_wdt_register(wdt); | |
497 | } | |
498 | ||
7a23f80e TW |
499 | /** |
500 | * mei_wdt_event - callback for event receive | |
501 | * | |
502 | * @cldev: bus device | |
503 | * @events: event mask | |
504 | * @context: callback context | |
505 | */ | |
506 | static void mei_wdt_event(struct mei_cl_device *cldev, | |
507 | u32 events, void *context) | |
508 | { | |
509 | if (events & BIT(MEI_CL_EVENT_RX)) | |
510 | mei_wdt_event_rx(cldev); | |
3a20a5c3 TW |
511 | |
512 | if (events & BIT(MEI_CL_EVENT_NOTIF)) | |
513 | mei_wdt_notify_event(cldev); | |
7a23f80e TW |
514 | } |
515 | ||
c9cf20ee TW |
516 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
517 | ||
ad1cd720 TW |
518 | static ssize_t mei_dbgfs_read_activation(struct file *file, char __user *ubuf, |
519 | size_t cnt, loff_t *ppos) | |
520 | { | |
521 | struct mei_wdt *wdt = file->private_data; | |
522 | const size_t bufsz = 32; | |
523 | char buf[32]; | |
524 | ssize_t pos; | |
525 | ||
526 | mutex_lock(&wdt->reg_lock); | |
527 | pos = scnprintf(buf, bufsz, "%s\n", | |
528 | __mei_wdt_is_registered(wdt) ? "activated" : "deactivated"); | |
529 | mutex_unlock(&wdt->reg_lock); | |
530 | ||
531 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, pos); | |
532 | } | |
533 | ||
534 | static const struct file_operations dbgfs_fops_activation = { | |
535 | .open = simple_open, | |
536 | .read = mei_dbgfs_read_activation, | |
537 | .llseek = generic_file_llseek, | |
538 | }; | |
539 | ||
c9cf20ee TW |
540 | static ssize_t mei_dbgfs_read_state(struct file *file, char __user *ubuf, |
541 | size_t cnt, loff_t *ppos) | |
542 | { | |
543 | struct mei_wdt *wdt = file->private_data; | |
544 | const size_t bufsz = 32; | |
545 | char buf[bufsz]; | |
546 | ssize_t pos; | |
547 | ||
548 | pos = scnprintf(buf, bufsz, "state: %s\n", | |
549 | mei_wdt_state_str(wdt->state)); | |
550 | ||
551 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, pos); | |
552 | } | |
553 | ||
554 | static const struct file_operations dbgfs_fops_state = { | |
555 | .open = simple_open, | |
556 | .read = mei_dbgfs_read_state, | |
557 | .llseek = generic_file_llseek, | |
558 | }; | |
559 | ||
560 | static void dbgfs_unregister(struct mei_wdt *wdt) | |
561 | { | |
562 | debugfs_remove_recursive(wdt->dbgfs_dir); | |
563 | wdt->dbgfs_dir = NULL; | |
564 | } | |
565 | ||
566 | static int dbgfs_register(struct mei_wdt *wdt) | |
567 | { | |
568 | struct dentry *dir, *f; | |
569 | ||
570 | dir = debugfs_create_dir(KBUILD_MODNAME, NULL); | |
571 | if (!dir) | |
572 | return -ENOMEM; | |
573 | ||
574 | wdt->dbgfs_dir = dir; | |
575 | f = debugfs_create_file("state", S_IRUSR, dir, wdt, &dbgfs_fops_state); | |
576 | if (!f) | |
577 | goto err; | |
578 | ||
ad1cd720 TW |
579 | f = debugfs_create_file("activation", S_IRUSR, |
580 | dir, wdt, &dbgfs_fops_activation); | |
581 | if (!f) | |
582 | goto err; | |
583 | ||
c9cf20ee TW |
584 | return 0; |
585 | err: | |
586 | dbgfs_unregister(wdt); | |
587 | return -ENODEV; | |
588 | } | |
589 | ||
590 | #else | |
591 | ||
592 | static inline void dbgfs_unregister(struct mei_wdt *wdt) {} | |
593 | ||
594 | static inline int dbgfs_register(struct mei_wdt *wdt) | |
595 | { | |
596 | return 0; | |
597 | } | |
598 | #endif /* CONFIG_DEBUG_FS */ | |
599 | ||
222818c3 TW |
600 | static int mei_wdt_probe(struct mei_cl_device *cldev, |
601 | const struct mei_cl_device_id *id) | |
602 | { | |
603 | struct mei_wdt *wdt; | |
604 | int ret; | |
605 | ||
606 | wdt = kzalloc(sizeof(struct mei_wdt), GFP_KERNEL); | |
607 | if (!wdt) | |
608 | return -ENOMEM; | |
609 | ||
610 | wdt->timeout = MEI_WDT_DEFAULT_TIMEOUT; | |
7a23f80e | 611 | wdt->state = MEI_WDT_PROBE; |
222818c3 | 612 | wdt->cldev = cldev; |
7a23f80e TW |
613 | wdt->resp_required = mei_cldev_ver(cldev) > 0x1; |
614 | mutex_init(&wdt->reg_lock); | |
615 | init_completion(&wdt->response); | |
616 | INIT_WORK(&wdt->unregister, mei_wdt_unregister_work); | |
617 | ||
222818c3 TW |
618 | mei_cldev_set_drvdata(cldev, wdt); |
619 | ||
620 | ret = mei_cldev_enable(cldev); | |
621 | if (ret < 0) { | |
622 | dev_err(&cldev->dev, "Could not enable cl device\n"); | |
623 | goto err_out; | |
624 | } | |
625 | ||
3a20a5c3 TW |
626 | ret = mei_cldev_register_event_cb(wdt->cldev, |
627 | BIT(MEI_CL_EVENT_RX) | | |
628 | BIT(MEI_CL_EVENT_NOTIF), | |
7a23f80e | 629 | mei_wdt_event, NULL); |
3a20a5c3 TW |
630 | |
631 | /* on legacy devices notification is not supported | |
632 | * this doesn't fail the registration for RX event | |
633 | */ | |
634 | if (ret && ret != -EOPNOTSUPP) { | |
7a23f80e TW |
635 | dev_err(&cldev->dev, "Could not register event ret=%d\n", ret); |
636 | goto err_disable; | |
637 | } | |
638 | ||
222818c3 TW |
639 | wd_info.firmware_version = mei_cldev_ver(cldev); |
640 | ||
7a23f80e TW |
641 | if (wdt->resp_required) |
642 | ret = mei_wdt_ping(wdt); | |
643 | else | |
644 | ret = mei_wdt_register(wdt); | |
645 | ||
222818c3 TW |
646 | if (ret) |
647 | goto err_disable; | |
648 | ||
c9cf20ee TW |
649 | if (dbgfs_register(wdt)) |
650 | dev_warn(&cldev->dev, "cannot register debugfs\n"); | |
651 | ||
222818c3 TW |
652 | return 0; |
653 | ||
654 | err_disable: | |
655 | mei_cldev_disable(cldev); | |
656 | ||
657 | err_out: | |
658 | kfree(wdt); | |
659 | ||
660 | return ret; | |
661 | } | |
662 | ||
663 | static int mei_wdt_remove(struct mei_cl_device *cldev) | |
664 | { | |
665 | struct mei_wdt *wdt = mei_cldev_get_drvdata(cldev); | |
666 | ||
7a23f80e TW |
667 | /* Free the caller in case of fw initiated or unexpected reset */ |
668 | if (!completion_done(&wdt->response)) | |
669 | complete(&wdt->response); | |
670 | ||
671 | cancel_work_sync(&wdt->unregister); | |
672 | ||
222818c3 TW |
673 | mei_wdt_unregister(wdt); |
674 | ||
675 | mei_cldev_disable(cldev); | |
676 | ||
c9cf20ee TW |
677 | dbgfs_unregister(wdt); |
678 | ||
222818c3 TW |
679 | kfree(wdt); |
680 | ||
681 | return 0; | |
682 | } | |
683 | ||
684 | #define MEI_UUID_WD UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, \ | |
685 | 0x89, 0x9D, 0xA9, 0x15, 0x14, 0xCB, 0x32, 0xAB) | |
686 | ||
687 | static struct mei_cl_device_id mei_wdt_tbl[] = { | |
7a23f80e | 688 | { .uuid = MEI_UUID_WD, .version = MEI_CL_VERSION_ANY }, |
222818c3 TW |
689 | /* required last entry */ |
690 | { } | |
691 | }; | |
692 | MODULE_DEVICE_TABLE(mei, mei_wdt_tbl); | |
693 | ||
694 | static struct mei_cl_driver mei_wdt_driver = { | |
695 | .id_table = mei_wdt_tbl, | |
696 | .name = KBUILD_MODNAME, | |
697 | ||
698 | .probe = mei_wdt_probe, | |
699 | .remove = mei_wdt_remove, | |
700 | }; | |
701 | ||
702 | static int __init mei_wdt_init(void) | |
703 | { | |
704 | int ret; | |
705 | ||
706 | ret = mei_cldev_driver_register(&mei_wdt_driver); | |
707 | if (ret) { | |
708 | pr_err(KBUILD_MODNAME ": module registration failed\n"); | |
709 | return ret; | |
710 | } | |
711 | return 0; | |
712 | } | |
713 | ||
714 | static void __exit mei_wdt_exit(void) | |
715 | { | |
716 | mei_cldev_driver_unregister(&mei_wdt_driver); | |
717 | } | |
718 | ||
719 | module_init(mei_wdt_init); | |
720 | module_exit(mei_wdt_exit); | |
721 | ||
722 | MODULE_AUTHOR("Intel Corporation"); | |
723 | MODULE_LICENSE("GPL"); | |
724 | MODULE_DESCRIPTION("Device driver for Intel MEI iAMT watchdog"); |