xref: /linux/drivers/misc/mei/interrupt.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
4  * Intel Management Engine Interface (Intel MEI) Linux driver
5  */
6 
7 #include <linux/export.h>
8 #include <linux/kthread.h>
9 #include <linux/interrupt.h>
10 #include <linux/fs.h>
11 #include <linux/jiffies.h>
12 #include <linux/slab.h>
13 #include <linux/pm_runtime.h>
14 
15 #include <linux/mei.h>
16 
17 #include "mei_dev.h"
18 #include "hbm.h"
19 #include "client.h"
20 
21 
22 /**
23  * mei_irq_compl_handler - dispatch complete handlers
24  *	for the completed callbacks
25  *
26  * @dev: mei device
27  * @cmpl_list: list of completed cbs
28  */
mei_irq_compl_handler(struct mei_device * dev,struct list_head * cmpl_list)29 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
30 {
31 	struct mei_cl_cb *cb, *next;
32 	struct mei_cl *cl;
33 
34 	list_for_each_entry_safe(cb, next, cmpl_list, list) {
35 		cl = cb->cl;
36 		list_del_init(&cb->list);
37 
38 		dev_dbg(dev->dev, "completing call back.\n");
39 		mei_cl_complete(cl, cb);
40 	}
41 }
42 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
43 
44 /**
45  * mei_cl_hbm_equal - check if hbm is addressed to the client
46  *
47  * @cl: host client
48  * @mei_hdr: header of mei client message
49  *
50  * Return: true if matches, false otherwise
51  */
mei_cl_hbm_equal(struct mei_cl * cl,struct mei_msg_hdr * mei_hdr)52 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
53 			struct mei_msg_hdr *mei_hdr)
54 {
55 	return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
56 		mei_cl_me_id(cl) == mei_hdr->me_addr;
57 }
58 
59 /**
60  * mei_irq_discard_msg  - discard received message
61  *
62  * @dev: mei device
63  * @hdr: message header
64  * @discard_len: the length of the message to discard (excluding header)
65  */
mei_irq_discard_msg(struct mei_device * dev,struct mei_msg_hdr * hdr,size_t discard_len)66 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr,
67 				size_t discard_len)
68 {
69 	if (hdr->dma_ring) {
70 		mei_dma_ring_read(dev, NULL,
71 				  hdr->extension[dev->rd_msg_hdr_count - 2]);
72 		discard_len = 0;
73 	}
74 	/*
75 	 * no need to check for size as it is guaranteed
76 	 * that length fits into rd_msg_buf
77 	 */
78 	mei_read_slots(dev, dev->rd_msg_buf, discard_len);
79 	dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
80 		MEI_HDR_PRM(hdr));
81 }
82 
83 /**
84  * mei_cl_irq_read_msg - process client message
85  *
86  * @cl: reading client
87  * @mei_hdr: header of mei client message
88  * @meta: extend meta header
89  * @cmpl_list: completion list
90  *
91  * Return: always 0
92  */
mei_cl_irq_read_msg(struct mei_cl * cl,struct mei_msg_hdr * mei_hdr,struct mei_ext_meta_hdr * meta,struct list_head * cmpl_list)93 static int mei_cl_irq_read_msg(struct mei_cl *cl,
94 			       struct mei_msg_hdr *mei_hdr,
95 			       struct mei_ext_meta_hdr *meta,
96 			       struct list_head *cmpl_list)
97 {
98 	struct mei_device *dev = cl->dev;
99 	struct mei_cl_cb *cb;
100 
101 	struct mei_ext_hdr_vtag *vtag_hdr = NULL;
102 	struct mei_ext_hdr_gsc_f2h *gsc_f2h = NULL;
103 
104 	size_t buf_sz;
105 	u32 length;
106 	u32 ext_len;
107 
108 	length = mei_hdr->length;
109 	ext_len = 0;
110 	if (mei_hdr->extended) {
111 		ext_len = sizeof(*meta) + mei_slots2data(meta->size);
112 		length -= ext_len;
113 	}
114 
115 	cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
116 	if (!cb) {
117 		if (!mei_cl_is_fixed_address(cl)) {
118 			cl_err(dev, cl, "pending read cb not found\n");
119 			goto discard;
120 		}
121 		cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
122 		if (!cb)
123 			goto discard;
124 		list_add_tail(&cb->list, &cl->rd_pending);
125 	}
126 
127 	if (mei_hdr->extended) {
128 		struct mei_ext_hdr *ext = mei_ext_begin(meta);
129 		do {
130 			switch (ext->type) {
131 			case MEI_EXT_HDR_VTAG:
132 				vtag_hdr = (struct mei_ext_hdr_vtag *)ext;
133 				break;
134 			case MEI_EXT_HDR_GSC:
135 				gsc_f2h = (struct mei_ext_hdr_gsc_f2h *)ext;
136 				cb->ext_hdr = kzalloc(sizeof(*gsc_f2h), GFP_KERNEL);
137 				if (!cb->ext_hdr) {
138 					cb->status = -ENOMEM;
139 					goto discard;
140 				}
141 				break;
142 			case MEI_EXT_HDR_NONE:
143 				fallthrough;
144 			default:
145 				cl_err(dev, cl, "unknown extended header\n");
146 				cb->status = -EPROTO;
147 				break;
148 			}
149 
150 			ext = mei_ext_next(ext);
151 		} while (!mei_ext_last(meta, ext));
152 
153 		if (!vtag_hdr && !gsc_f2h) {
154 			cl_dbg(dev, cl, "no vtag or gsc found in extended header.\n");
155 			cb->status = -EPROTO;
156 			goto discard;
157 		}
158 	}
159 
160 	if (vtag_hdr) {
161 		cl_dbg(dev, cl, "vtag: %d\n", vtag_hdr->vtag);
162 		if (cb->vtag && cb->vtag != vtag_hdr->vtag) {
163 			cl_err(dev, cl, "mismatched tag: %d != %d\n",
164 			       cb->vtag, vtag_hdr->vtag);
165 			cb->status = -EPROTO;
166 			goto discard;
167 		}
168 		cb->vtag = vtag_hdr->vtag;
169 	}
170 
171 	if (gsc_f2h) {
172 		u32 ext_hdr_len = mei_ext_hdr_len(&gsc_f2h->hdr);
173 
174 		if (!dev->hbm_f_gsc_supported) {
175 			cl_err(dev, cl, "gsc extended header is not supported\n");
176 			cb->status = -EPROTO;
177 			goto discard;
178 		}
179 
180 		if (length) {
181 			cl_err(dev, cl, "no data allowed in cb with gsc\n");
182 			cb->status = -EPROTO;
183 			goto discard;
184 		}
185 		if (ext_hdr_len > sizeof(*gsc_f2h)) {
186 			cl_err(dev, cl, "gsc extended header is too big %u\n", ext_hdr_len);
187 			cb->status = -EPROTO;
188 			goto discard;
189 		}
190 		memcpy(cb->ext_hdr, gsc_f2h, ext_hdr_len);
191 	}
192 
193 	if (!mei_cl_is_connected(cl)) {
194 		cl_dbg(dev, cl, "not connected\n");
195 		cb->status = -ENODEV;
196 		goto discard;
197 	}
198 
199 	if (mei_hdr->dma_ring)
200 		length = mei_hdr->extension[mei_data2slots(ext_len)];
201 
202 	buf_sz = length + cb->buf_idx;
203 	/* catch for integer overflow */
204 	if (buf_sz < cb->buf_idx) {
205 		cl_err(dev, cl, "message is too big len %d idx %zu\n",
206 		       length, cb->buf_idx);
207 		cb->status = -EMSGSIZE;
208 		goto discard;
209 	}
210 
211 	if (cb->buf.size < buf_sz) {
212 		cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
213 			cb->buf.size, length, cb->buf_idx);
214 		cb->status = -EMSGSIZE;
215 		goto discard;
216 	}
217 
218 	if (mei_hdr->dma_ring) {
219 		mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
220 		/*  for DMA read 0 length to generate interrupt to the device */
221 		mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
222 	} else {
223 		mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
224 	}
225 
226 	cb->buf_idx += length;
227 
228 	if (mei_hdr->msg_complete) {
229 		cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
230 		list_move_tail(&cb->list, cmpl_list);
231 	} else {
232 		pm_runtime_mark_last_busy(dev->dev);
233 		pm_request_autosuspend(dev->dev);
234 	}
235 
236 	return 0;
237 
238 discard:
239 	if (cb)
240 		list_move_tail(&cb->list, cmpl_list);
241 	mei_irq_discard_msg(dev, mei_hdr, length);
242 	return 0;
243 }
244 
245 /**
246  * mei_cl_irq_disconnect_rsp - send disconnection response message
247  *
248  * @cl: client
249  * @cb: callback block.
250  * @cmpl_list: complete list.
251  *
252  * Return: 0, OK; otherwise, error.
253  */
mei_cl_irq_disconnect_rsp(struct mei_cl * cl,struct mei_cl_cb * cb,struct list_head * cmpl_list)254 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
255 				     struct list_head *cmpl_list)
256 {
257 	struct mei_device *dev = cl->dev;
258 	u32 msg_slots;
259 	int slots;
260 	int ret;
261 
262 	msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
263 	slots = mei_hbuf_empty_slots(dev);
264 	if (slots < 0)
265 		return -EOVERFLOW;
266 
267 	if ((u32)slots < msg_slots)
268 		return -EMSGSIZE;
269 
270 	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
271 	list_move_tail(&cb->list, cmpl_list);
272 
273 	return ret;
274 }
275 
276 /**
277  * mei_cl_irq_read - processes client read related operation from the
278  *	interrupt thread context - request for flow control credits
279  *
280  * @cl: client
281  * @cb: callback block.
282  * @cmpl_list: complete list.
283  *
284  * Return: 0, OK; otherwise, error.
285  */
mei_cl_irq_read(struct mei_cl * cl,struct mei_cl_cb * cb,struct list_head * cmpl_list)286 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
287 			   struct list_head *cmpl_list)
288 {
289 	struct mei_device *dev = cl->dev;
290 	u32 msg_slots;
291 	int slots;
292 	int ret;
293 
294 	if (!list_empty(&cl->rd_pending))
295 		return 0;
296 
297 	msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
298 	slots = mei_hbuf_empty_slots(dev);
299 	if (slots < 0)
300 		return -EOVERFLOW;
301 
302 	if ((u32)slots < msg_slots)
303 		return -EMSGSIZE;
304 
305 	ret = mei_hbm_cl_flow_control_req(dev, cl);
306 	if (ret) {
307 		cl->status = ret;
308 		cb->buf_idx = 0;
309 		list_move_tail(&cb->list, cmpl_list);
310 		return ret;
311 	}
312 
313 	pm_runtime_mark_last_busy(dev->dev);
314 	pm_request_autosuspend(dev->dev);
315 
316 	list_move_tail(&cb->list, &cl->rd_pending);
317 
318 	return 0;
319 }
320 
hdr_is_hbm(struct mei_msg_hdr * mei_hdr)321 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
322 {
323 	return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
324 }
325 
hdr_is_fixed(struct mei_msg_hdr * mei_hdr)326 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
327 {
328 	return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
329 }
330 
hdr_is_valid(u32 msg_hdr)331 static inline int hdr_is_valid(u32 msg_hdr)
332 {
333 	struct mei_msg_hdr *mei_hdr;
334 	u32 expected_len = 0;
335 
336 	mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
337 	if (!msg_hdr || mei_hdr->reserved)
338 		return -EBADMSG;
339 
340 	if (mei_hdr->dma_ring)
341 		expected_len += MEI_SLOT_SIZE;
342 	if (mei_hdr->extended)
343 		expected_len += MEI_SLOT_SIZE;
344 	if (mei_hdr->length < expected_len)
345 		return -EBADMSG;
346 
347 	return 0;
348 }
349 
350 /**
351  * mei_irq_read_handler - bottom half read routine after ISR to
352  * handle the read processing.
353  *
354  * @dev: the device structure
355  * @cmpl_list: An instance of our list structure
356  * @slots: slots to read.
357  *
358  * Return: 0 on success, <0 on failure.
359  */
mei_irq_read_handler(struct mei_device * dev,struct list_head * cmpl_list,s32 * slots)360 int mei_irq_read_handler(struct mei_device *dev,
361 			 struct list_head *cmpl_list, s32 *slots)
362 {
363 	struct mei_msg_hdr *mei_hdr;
364 	struct mei_ext_meta_hdr *meta_hdr = NULL;
365 	struct mei_cl *cl;
366 	int ret;
367 	u32 hdr_size_left;
368 	u32 hdr_size_ext;
369 	int i;
370 	int ext_hdr_end;
371 
372 	if (!dev->rd_msg_hdr[0]) {
373 		dev->rd_msg_hdr[0] = mei_read_hdr(dev);
374 		dev->rd_msg_hdr_count = 1;
375 		(*slots)--;
376 		dev_dbg(dev->dev, "slots =%08x.\n", *slots);
377 
378 		ret = hdr_is_valid(dev->rd_msg_hdr[0]);
379 		if (ret) {
380 			dev_err(dev->dev, "corrupted message header 0x%08X\n",
381 				dev->rd_msg_hdr[0]);
382 			goto end;
383 		}
384 	}
385 
386 	mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
387 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
388 
389 	if (mei_slots2data(*slots) < mei_hdr->length) {
390 		dev_err(dev->dev, "less data available than length=%08x.\n",
391 				*slots);
392 		/* we can't read the message */
393 		ret = -ENODATA;
394 		goto end;
395 	}
396 
397 	ext_hdr_end = 1;
398 	hdr_size_left = mei_hdr->length;
399 
400 	if (mei_hdr->extended) {
401 		if (!dev->rd_msg_hdr[1]) {
402 			dev->rd_msg_hdr[1] = mei_read_hdr(dev);
403 			dev->rd_msg_hdr_count++;
404 			(*slots)--;
405 			dev_dbg(dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]);
406 		}
407 		meta_hdr = ((struct mei_ext_meta_hdr *)&dev->rd_msg_hdr[1]);
408 		if (check_add_overflow((u32)sizeof(*meta_hdr),
409 				       mei_slots2data(meta_hdr->size),
410 				       &hdr_size_ext)) {
411 			dev_err(dev->dev, "extended message size too big %d\n",
412 				meta_hdr->size);
413 			return -EBADMSG;
414 		}
415 		if (hdr_size_left < hdr_size_ext) {
416 			dev_err(dev->dev, "corrupted message header len %d\n",
417 				mei_hdr->length);
418 			return -EBADMSG;
419 		}
420 		hdr_size_left -= hdr_size_ext;
421 
422 		ext_hdr_end = meta_hdr->size + 2;
423 		for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
424 			dev->rd_msg_hdr[i] = mei_read_hdr(dev);
425 			dev_dbg(dev->dev, "extended header %d is %08x\n", i,
426 				dev->rd_msg_hdr[i]);
427 			dev->rd_msg_hdr_count++;
428 			(*slots)--;
429 		}
430 	}
431 
432 	if (mei_hdr->dma_ring) {
433 		if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
434 			dev_err(dev->dev, "corrupted message header len %d\n",
435 				mei_hdr->length);
436 			return -EBADMSG;
437 		}
438 
439 		dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
440 		dev->rd_msg_hdr_count++;
441 		(*slots)--;
442 		mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
443 	}
444 
445 	/*  HBM message */
446 	if (hdr_is_hbm(mei_hdr)) {
447 		ret = mei_hbm_dispatch(dev, mei_hdr);
448 		if (ret) {
449 			dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
450 					ret);
451 			goto end;
452 		}
453 		goto reset_slots;
454 	}
455 
456 	/* find recipient cl */
457 	list_for_each_entry(cl, &dev->file_list, link) {
458 		if (mei_cl_hbm_equal(cl, mei_hdr)) {
459 			cl_dbg(dev, cl, "got a message\n");
460 			ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
461 			goto reset_slots;
462 		}
463 	}
464 
465 	/* if no recipient cl was found we assume corrupted header */
466 	/* A message for not connected fixed address clients
467 	 * should be silently discarded
468 	 * On power down client may be force cleaned,
469 	 * silently discard such messages
470 	 */
471 	if (hdr_is_fixed(mei_hdr) ||
472 	    dev->dev_state == MEI_DEV_POWER_DOWN) {
473 		mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
474 		ret = 0;
475 		goto reset_slots;
476 	}
477 	dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
478 	ret = -EBADMSG;
479 	goto end;
480 
481 reset_slots:
482 	/* reset the number of slots and header */
483 	memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
484 	dev->rd_msg_hdr_count = 0;
485 	*slots = mei_count_full_read_slots(dev);
486 	if (*slots == -EOVERFLOW) {
487 		/* overflow - reset */
488 		dev_err(dev->dev, "resetting due to slots overflow.\n");
489 		/* set the event since message has been read */
490 		ret = -ERANGE;
491 		goto end;
492 	}
493 end:
494 	return ret;
495 }
496 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
497 
498 
499 /**
500  * mei_irq_write_handler -  dispatch write requests
501  *  after irq received
502  *
503  * @dev: the device structure
504  * @cmpl_list: An instance of our list structure
505  *
506  * Return: 0 on success, <0 on failure.
507  */
mei_irq_write_handler(struct mei_device * dev,struct list_head * cmpl_list)508 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
509 {
510 
511 	struct mei_cl *cl;
512 	struct mei_cl_cb *cb, *next;
513 	s32 slots;
514 	int ret;
515 
516 
517 	if (!mei_hbuf_acquire(dev))
518 		return 0;
519 
520 	slots = mei_hbuf_empty_slots(dev);
521 	if (slots < 0)
522 		return -EOVERFLOW;
523 
524 	if (slots == 0)
525 		return -EMSGSIZE;
526 
527 	/* complete all waiting for write CB */
528 	dev_dbg(dev->dev, "complete all waiting for write cb.\n");
529 
530 	list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
531 		cl = cb->cl;
532 
533 		cl->status = 0;
534 		cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
535 		cl->writing_state = MEI_WRITE_COMPLETE;
536 		list_move_tail(&cb->list, cmpl_list);
537 	}
538 
539 	/* complete control write list CB */
540 	dev_dbg(dev->dev, "complete control write list cb.\n");
541 	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
542 		cl = cb->cl;
543 		switch (cb->fop_type) {
544 		case MEI_FOP_DISCONNECT:
545 			/* send disconnect message */
546 			ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
547 			if (ret)
548 				return ret;
549 
550 			break;
551 		case MEI_FOP_READ:
552 			/* send flow control message */
553 			ret = mei_cl_irq_read(cl, cb, cmpl_list);
554 			if (ret)
555 				return ret;
556 
557 			break;
558 		case MEI_FOP_CONNECT:
559 			/* connect message */
560 			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
561 			if (ret)
562 				return ret;
563 
564 			break;
565 		case MEI_FOP_DISCONNECT_RSP:
566 			/* send disconnect resp */
567 			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
568 			if (ret)
569 				return ret;
570 			break;
571 
572 		case MEI_FOP_NOTIFY_START:
573 		case MEI_FOP_NOTIFY_STOP:
574 			ret = mei_cl_irq_notify(cl, cb, cmpl_list);
575 			if (ret)
576 				return ret;
577 			break;
578 		case MEI_FOP_DMA_MAP:
579 			ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
580 			if (ret)
581 				return ret;
582 			break;
583 		case MEI_FOP_DMA_UNMAP:
584 			ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
585 			if (ret)
586 				return ret;
587 			break;
588 		default:
589 			BUG();
590 		}
591 
592 	}
593 	/* complete  write list CB */
594 	dev_dbg(dev->dev, "complete write list cb.\n");
595 	list_for_each_entry_safe(cb, next, &dev->write_list, list) {
596 		cl = cb->cl;
597 		ret = mei_cl_irq_write(cl, cb, cmpl_list);
598 		if (ret)
599 			return ret;
600 	}
601 	return 0;
602 }
603 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
604 
605 
606 /**
607  * mei_connect_timeout  - connect/disconnect timeouts
608  *
609  * @cl: host client
610  */
mei_connect_timeout(struct mei_cl * cl)611 static void mei_connect_timeout(struct mei_cl *cl)
612 {
613 	struct mei_device *dev = cl->dev;
614 
615 	if (cl->state == MEI_FILE_CONNECTING) {
616 		if (dev->hbm_f_dot_supported) {
617 			cl->state = MEI_FILE_DISCONNECT_REQUIRED;
618 			wake_up(&cl->wait);
619 			return;
620 		}
621 	}
622 	mei_reset(dev);
623 }
624 
625 #define MEI_STALL_TIMER_FREQ (2 * HZ)
626 /**
627  * mei_schedule_stall_timer - re-arm stall_timer work
628  *
629  * @dev: the device structure
630  *
631  * Schedule stall timer
632  */
mei_schedule_stall_timer(struct mei_device * dev)633 void mei_schedule_stall_timer(struct mei_device *dev)
634 {
635 	schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
636 }
637 
638 /**
639  * mei_timer - timer function.
640  *
641  * @work: pointer to the work_struct structure
642  *
643  */
mei_timer(struct work_struct * work)644 void mei_timer(struct work_struct *work)
645 {
646 	struct mei_cl *cl;
647 	struct mei_device *dev = container_of(work,
648 					struct mei_device, timer_work.work);
649 	bool reschedule_timer = false;
650 
651 	mutex_lock(&dev->device_lock);
652 
653 	/* Catch interrupt stalls during HBM init handshake */
654 	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
655 	    dev->hbm_state != MEI_HBM_IDLE) {
656 
657 		if (dev->init_clients_timer) {
658 			if (--dev->init_clients_timer == 0) {
659 				dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
660 					dev->hbm_state);
661 				mei_reset(dev);
662 				goto out;
663 			}
664 			reschedule_timer = true;
665 		}
666 	}
667 
668 	if (dev->dev_state != MEI_DEV_ENABLED)
669 		goto out;
670 
671 	/*** connect/disconnect timeouts ***/
672 	list_for_each_entry(cl, &dev->file_list, link) {
673 		if (cl->timer_count) {
674 			if (--cl->timer_count == 0) {
675 				dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
676 				mei_connect_timeout(cl);
677 				goto out;
678 			}
679 			reschedule_timer = true;
680 		}
681 	}
682 
683 out:
684 	if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
685 		mei_schedule_stall_timer(dev);
686 
687 	mutex_unlock(&dev->device_lock);
688 }
689