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 guarantied
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 size_t buf_sz;
102 u32 length;
103 int ext_len;
104
105 length = mei_hdr->length;
106 ext_len = 0;
107 if (mei_hdr->extended) {
108 ext_len = sizeof(*meta) + mei_slots2data(meta->size);
109 length -= ext_len;
110 }
111
112 cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
113 if (!cb) {
114 if (!mei_cl_is_fixed_address(cl)) {
115 cl_err(dev, cl, "pending read cb not found\n");
116 goto discard;
117 }
118 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
119 if (!cb)
120 goto discard;
121 list_add_tail(&cb->list, &cl->rd_pending);
122 }
123
124 if (mei_hdr->extended) {
125 struct mei_ext_hdr *ext;
126 struct mei_ext_hdr *vtag = NULL;
127
128 ext = mei_ext_begin(meta);
129 do {
130 switch (ext->type) {
131 case MEI_EXT_HDR_VTAG:
132 vtag = ext;
133 break;
134 case MEI_EXT_HDR_NONE:
135 fallthrough;
136 default:
137 cb->status = -EPROTO;
138 break;
139 }
140
141 ext = mei_ext_next(ext);
142 } while (!mei_ext_last(meta, ext));
143
144 if (!vtag) {
145 cl_dbg(dev, cl, "vtag not found in extended header.\n");
146 cb->status = -EPROTO;
147 goto discard;
148 }
149
150 cl_dbg(dev, cl, "vtag: %d\n", vtag->ext_payload[0]);
151 if (cb->vtag && cb->vtag != vtag->ext_payload[0]) {
152 cl_err(dev, cl, "mismatched tag: %d != %d\n",
153 cb->vtag, vtag->ext_payload[0]);
154 cb->status = -EPROTO;
155 goto discard;
156 }
157 cb->vtag = vtag->ext_payload[0];
158 }
159
160 if (!mei_cl_is_connected(cl)) {
161 cl_dbg(dev, cl, "not connected\n");
162 cb->status = -ENODEV;
163 goto discard;
164 }
165
166 if (mei_hdr->dma_ring)
167 length = mei_hdr->extension[mei_data2slots(ext_len)];
168
169 buf_sz = length + cb->buf_idx;
170 /* catch for integer overflow */
171 if (buf_sz < cb->buf_idx) {
172 cl_err(dev, cl, "message is too big len %d idx %zu\n",
173 length, cb->buf_idx);
174 cb->status = -EMSGSIZE;
175 goto discard;
176 }
177
178 if (cb->buf.size < buf_sz) {
179 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
180 cb->buf.size, length, cb->buf_idx);
181 cb->status = -EMSGSIZE;
182 goto discard;
183 }
184
185 if (mei_hdr->dma_ring) {
186 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
187 /* for DMA read 0 length to generate interrupt to the device */
188 mei_read_slots(dev, cb->buf.data + cb->buf_idx, 0);
189 } else {
190 mei_read_slots(dev, cb->buf.data + cb->buf_idx, length);
191 }
192
193 cb->buf_idx += length;
194
195 if (mei_hdr->msg_complete) {
196 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
197 list_move_tail(&cb->list, cmpl_list);
198 } else {
199 pm_runtime_mark_last_busy(dev->dev);
200 pm_request_autosuspend(dev->dev);
201 }
202
203 return 0;
204
205 discard:
206 if (cb)
207 list_move_tail(&cb->list, cmpl_list);
208 mei_irq_discard_msg(dev, mei_hdr, length);
209 return 0;
210 }
211
212 /**
213 * mei_cl_irq_disconnect_rsp - send disconnection response message
214 *
215 * @cl: client
216 * @cb: callback block.
217 * @cmpl_list: complete list.
218 *
219 * Return: 0, OK; otherwise, error.
220 */
mei_cl_irq_disconnect_rsp(struct mei_cl * cl,struct mei_cl_cb * cb,struct list_head * cmpl_list)221 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
222 struct list_head *cmpl_list)
223 {
224 struct mei_device *dev = cl->dev;
225 u32 msg_slots;
226 int slots;
227 int ret;
228
229 msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
230 slots = mei_hbuf_empty_slots(dev);
231 if (slots < 0)
232 return -EOVERFLOW;
233
234 if ((u32)slots < msg_slots)
235 return -EMSGSIZE;
236
237 ret = mei_hbm_cl_disconnect_rsp(dev, cl);
238 list_move_tail(&cb->list, cmpl_list);
239
240 return ret;
241 }
242
243 /**
244 * mei_cl_irq_read - processes client read related operation from the
245 * interrupt thread context - request for flow control credits
246 *
247 * @cl: client
248 * @cb: callback block.
249 * @cmpl_list: complete list.
250 *
251 * Return: 0, OK; otherwise, error.
252 */
mei_cl_irq_read(struct mei_cl * cl,struct mei_cl_cb * cb,struct list_head * cmpl_list)253 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
254 struct list_head *cmpl_list)
255 {
256 struct mei_device *dev = cl->dev;
257 u32 msg_slots;
258 int slots;
259 int ret;
260
261 if (!list_empty(&cl->rd_pending))
262 return 0;
263
264 msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
265 slots = mei_hbuf_empty_slots(dev);
266 if (slots < 0)
267 return -EOVERFLOW;
268
269 if ((u32)slots < msg_slots)
270 return -EMSGSIZE;
271
272 ret = mei_hbm_cl_flow_control_req(dev, cl);
273 if (ret) {
274 cl->status = ret;
275 cb->buf_idx = 0;
276 list_move_tail(&cb->list, cmpl_list);
277 return ret;
278 }
279
280 pm_runtime_mark_last_busy(dev->dev);
281 pm_request_autosuspend(dev->dev);
282
283 list_move_tail(&cb->list, &cl->rd_pending);
284
285 return 0;
286 }
287
hdr_is_hbm(struct mei_msg_hdr * mei_hdr)288 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
289 {
290 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
291 }
292
hdr_is_fixed(struct mei_msg_hdr * mei_hdr)293 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
294 {
295 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
296 }
297
hdr_is_valid(u32 msg_hdr)298 static inline int hdr_is_valid(u32 msg_hdr)
299 {
300 struct mei_msg_hdr *mei_hdr;
301 u32 expected_len = 0;
302
303 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
304 if (!msg_hdr || mei_hdr->reserved)
305 return -EBADMSG;
306
307 if (mei_hdr->dma_ring)
308 expected_len += MEI_SLOT_SIZE;
309 if (mei_hdr->extended)
310 expected_len += MEI_SLOT_SIZE;
311 if (mei_hdr->length < expected_len)
312 return -EBADMSG;
313
314 return 0;
315 }
316
317 /**
318 * mei_irq_read_handler - bottom half read routine after ISR to
319 * handle the read processing.
320 *
321 * @dev: the device structure
322 * @cmpl_list: An instance of our list structure
323 * @slots: slots to read.
324 *
325 * Return: 0 on success, <0 on failure.
326 */
mei_irq_read_handler(struct mei_device * dev,struct list_head * cmpl_list,s32 * slots)327 int mei_irq_read_handler(struct mei_device *dev,
328 struct list_head *cmpl_list, s32 *slots)
329 {
330 struct mei_msg_hdr *mei_hdr;
331 struct mei_ext_meta_hdr *meta_hdr = NULL;
332 struct mei_cl *cl;
333 int ret;
334 u32 ext_meta_hdr_u32;
335 u32 hdr_size_left;
336 u32 hdr_size_ext;
337 int i;
338 int ext_hdr_end;
339
340 if (!dev->rd_msg_hdr[0]) {
341 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
342 dev->rd_msg_hdr_count = 1;
343 (*slots)--;
344 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
345
346 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
347 if (ret) {
348 dev_err(dev->dev, "corrupted message header 0x%08X\n",
349 dev->rd_msg_hdr[0]);
350 goto end;
351 }
352 }
353
354 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
355 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
356
357 if (mei_slots2data(*slots) < mei_hdr->length) {
358 dev_err(dev->dev, "less data available than length=%08x.\n",
359 *slots);
360 /* we can't read the message */
361 ret = -ENODATA;
362 goto end;
363 }
364
365 ext_hdr_end = 1;
366 hdr_size_left = mei_hdr->length;
367
368 if (mei_hdr->extended) {
369 if (!dev->rd_msg_hdr[1]) {
370 ext_meta_hdr_u32 = mei_read_hdr(dev);
371 dev->rd_msg_hdr[1] = ext_meta_hdr_u32;
372 dev->rd_msg_hdr_count++;
373 (*slots)--;
374 dev_dbg(dev->dev, "extended header is %08x\n",
375 ext_meta_hdr_u32);
376 }
377 meta_hdr = ((struct mei_ext_meta_hdr *)dev->rd_msg_hdr + 1);
378 if (check_add_overflow((u32)sizeof(*meta_hdr),
379 mei_slots2data(meta_hdr->size),
380 &hdr_size_ext)) {
381 dev_err(dev->dev, "extended message size too big %d\n",
382 meta_hdr->size);
383 return -EBADMSG;
384 }
385 if (hdr_size_left < hdr_size_ext) {
386 dev_err(dev->dev, "corrupted message header len %d\n",
387 mei_hdr->length);
388 return -EBADMSG;
389 }
390 hdr_size_left -= hdr_size_ext;
391
392 ext_hdr_end = meta_hdr->size + 2;
393 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
394 dev->rd_msg_hdr[i] = mei_read_hdr(dev);
395 dev_dbg(dev->dev, "extended header %d is %08x\n", i,
396 dev->rd_msg_hdr[i]);
397 dev->rd_msg_hdr_count++;
398 (*slots)--;
399 }
400 }
401
402 if (mei_hdr->dma_ring) {
403 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
404 dev_err(dev->dev, "corrupted message header len %d\n",
405 mei_hdr->length);
406 return -EBADMSG;
407 }
408
409 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
410 dev->rd_msg_hdr_count++;
411 (*slots)--;
412 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
413 }
414
415 /* HBM message */
416 if (hdr_is_hbm(mei_hdr)) {
417 ret = mei_hbm_dispatch(dev, mei_hdr);
418 if (ret) {
419 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
420 ret);
421 goto end;
422 }
423 goto reset_slots;
424 }
425
426 /* find recipient cl */
427 list_for_each_entry(cl, &dev->file_list, link) {
428 if (mei_cl_hbm_equal(cl, mei_hdr)) {
429 cl_dbg(dev, cl, "got a message\n");
430 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
431 goto reset_slots;
432 }
433 }
434
435 /* if no recipient cl was found we assume corrupted header */
436 /* A message for not connected fixed address clients
437 * should be silently discarded
438 * On power down client may be force cleaned,
439 * silently discard such messages
440 */
441 if (hdr_is_fixed(mei_hdr) ||
442 dev->dev_state == MEI_DEV_POWER_DOWN) {
443 mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
444 ret = 0;
445 goto reset_slots;
446 }
447 dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
448 ret = -EBADMSG;
449 goto end;
450
451 reset_slots:
452 /* reset the number of slots and header */
453 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
454 dev->rd_msg_hdr_count = 0;
455 *slots = mei_count_full_read_slots(dev);
456 if (*slots == -EOVERFLOW) {
457 /* overflow - reset */
458 dev_err(dev->dev, "resetting due to slots overflow.\n");
459 /* set the event since message has been read */
460 ret = -ERANGE;
461 goto end;
462 }
463 end:
464 return ret;
465 }
466 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
467
468
469 /**
470 * mei_irq_write_handler - dispatch write requests
471 * after irq received
472 *
473 * @dev: the device structure
474 * @cmpl_list: An instance of our list structure
475 *
476 * Return: 0 on success, <0 on failure.
477 */
mei_irq_write_handler(struct mei_device * dev,struct list_head * cmpl_list)478 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
479 {
480
481 struct mei_cl *cl;
482 struct mei_cl_cb *cb, *next;
483 s32 slots;
484 int ret;
485
486
487 if (!mei_hbuf_acquire(dev))
488 return 0;
489
490 slots = mei_hbuf_empty_slots(dev);
491 if (slots < 0)
492 return -EOVERFLOW;
493
494 if (slots == 0)
495 return -EMSGSIZE;
496
497 /* complete all waiting for write CB */
498 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
499
500 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
501 cl = cb->cl;
502
503 cl->status = 0;
504 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
505 cl->writing_state = MEI_WRITE_COMPLETE;
506 list_move_tail(&cb->list, cmpl_list);
507 }
508
509 /* complete control write list CB */
510 dev_dbg(dev->dev, "complete control write list cb.\n");
511 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
512 cl = cb->cl;
513 switch (cb->fop_type) {
514 case MEI_FOP_DISCONNECT:
515 /* send disconnect message */
516 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
517 if (ret)
518 return ret;
519
520 break;
521 case MEI_FOP_READ:
522 /* send flow control message */
523 ret = mei_cl_irq_read(cl, cb, cmpl_list);
524 if (ret)
525 return ret;
526
527 break;
528 case MEI_FOP_CONNECT:
529 /* connect message */
530 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
531 if (ret)
532 return ret;
533
534 break;
535 case MEI_FOP_DISCONNECT_RSP:
536 /* send disconnect resp */
537 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
538 if (ret)
539 return ret;
540 break;
541
542 case MEI_FOP_NOTIFY_START:
543 case MEI_FOP_NOTIFY_STOP:
544 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
545 if (ret)
546 return ret;
547 break;
548 default:
549 BUG();
550 }
551
552 }
553 /* complete write list CB */
554 dev_dbg(dev->dev, "complete write list cb.\n");
555 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
556 cl = cb->cl;
557 ret = mei_cl_irq_write(cl, cb, cmpl_list);
558 if (ret)
559 return ret;
560 }
561 return 0;
562 }
563 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
564
565
566 /**
567 * mei_connect_timeout - connect/disconnect timeouts
568 *
569 * @cl: host client
570 */
mei_connect_timeout(struct mei_cl * cl)571 static void mei_connect_timeout(struct mei_cl *cl)
572 {
573 struct mei_device *dev = cl->dev;
574
575 if (cl->state == MEI_FILE_CONNECTING) {
576 if (dev->hbm_f_dot_supported) {
577 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
578 wake_up(&cl->wait);
579 return;
580 }
581 }
582 mei_reset(dev);
583 }
584
585 #define MEI_STALL_TIMER_FREQ (2 * HZ)
586 /**
587 * mei_schedule_stall_timer - re-arm stall_timer work
588 *
589 * Schedule stall timer
590 *
591 * @dev: the device structure
592 */
mei_schedule_stall_timer(struct mei_device * dev)593 void mei_schedule_stall_timer(struct mei_device *dev)
594 {
595 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
596 }
597
598 /**
599 * mei_timer - timer function.
600 *
601 * @work: pointer to the work_struct structure
602 *
603 */
mei_timer(struct work_struct * work)604 void mei_timer(struct work_struct *work)
605 {
606 struct mei_cl *cl;
607 struct mei_device *dev = container_of(work,
608 struct mei_device, timer_work.work);
609 bool reschedule_timer = false;
610
611 mutex_lock(&dev->device_lock);
612
613 /* Catch interrupt stalls during HBM init handshake */
614 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
615 dev->hbm_state != MEI_HBM_IDLE) {
616
617 if (dev->init_clients_timer) {
618 if (--dev->init_clients_timer == 0) {
619 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
620 dev->hbm_state);
621 mei_reset(dev);
622 goto out;
623 }
624 reschedule_timer = true;
625 }
626 }
627
628 if (dev->dev_state != MEI_DEV_ENABLED)
629 goto out;
630
631 /*** connect/disconnect timeouts ***/
632 list_for_each_entry(cl, &dev->file_list, link) {
633 if (cl->timer_count) {
634 if (--cl->timer_count == 0) {
635 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
636 mei_connect_timeout(cl);
637 goto out;
638 }
639 reschedule_timer = true;
640 }
641 }
642
643 out:
644 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
645 mei_schedule_stall_timer(dev);
646
647 mutex_unlock(&dev->device_lock);
648 }
649