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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 */
29void 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 cl_dbg(dev, cl, "completing call back.\n");
39 mei_cl_complete(cl, cb);
40 }
41}
42EXPORT_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 */
52static 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 */
66static 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 */
93static 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 = (struct mei_ext_hdr *) kzalloc_obj(*gsc_f2h);
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_request_autosuspend(dev->parent);
233 }
234
235 return 0;
236
237discard:
238 if (cb)
239 list_move_tail(&cb->list, cmpl_list);
240 mei_irq_discard_msg(dev, mei_hdr, length);
241 return 0;
242}
243
244/**
245 * mei_cl_irq_disconnect_rsp - send disconnection response message
246 *
247 * @cl: client
248 * @cb: callback block.
249 * @cmpl_list: complete list.
250 *
251 * Return: 0, OK; otherwise, error.
252 */
253static int mei_cl_irq_disconnect_rsp(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 msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
262 slots = mei_hbuf_empty_slots(dev);
263 if (slots < 0)
264 return -EOVERFLOW;
265
266 if ((u32)slots < msg_slots)
267 return -EMSGSIZE;
268
269 ret = mei_hbm_cl_disconnect_rsp(dev, cl);
270 list_move_tail(&cb->list, cmpl_list);
271
272 return ret;
273}
274
275/**
276 * mei_cl_irq_read - processes client read related operation from the
277 * interrupt thread context - request for flow control credits
278 *
279 * @cl: client
280 * @cb: callback block.
281 * @cmpl_list: complete list.
282 *
283 * Return: 0, OK; otherwise, error.
284 */
285static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
286 struct list_head *cmpl_list)
287{
288 struct mei_device *dev = cl->dev;
289 u32 msg_slots;
290 int slots;
291 int ret;
292
293 if (!list_empty(&cl->rd_pending))
294 return 0;
295
296 msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
297 slots = mei_hbuf_empty_slots(dev);
298 if (slots < 0)
299 return -EOVERFLOW;
300
301 if ((u32)slots < msg_slots)
302 return -EMSGSIZE;
303
304 ret = mei_hbm_cl_flow_control_req(dev, cl);
305 if (ret) {
306 cl->status = ret;
307 cb->buf_idx = 0;
308 list_move_tail(&cb->list, cmpl_list);
309 return ret;
310 }
311
312 pm_request_autosuspend(dev->parent);
313
314 list_move_tail(&cb->list, &cl->rd_pending);
315
316 return 0;
317}
318
319static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
320{
321 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
322}
323
324static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
325{
326 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
327}
328
329static inline int hdr_is_valid(u32 msg_hdr)
330{
331 struct mei_msg_hdr *mei_hdr;
332 u32 expected_len = 0;
333
334 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
335 if (!msg_hdr || mei_hdr->reserved)
336 return -EBADMSG;
337
338 if (mei_hdr->dma_ring)
339 expected_len += MEI_SLOT_SIZE;
340 if (mei_hdr->extended)
341 expected_len += MEI_SLOT_SIZE;
342 if (mei_hdr->length < expected_len)
343 return -EBADMSG;
344
345 return 0;
346}
347
348/**
349 * mei_irq_read_handler - bottom half read routine after ISR to
350 * handle the read processing.
351 *
352 * @dev: the device structure
353 * @cmpl_list: An instance of our list structure
354 * @slots: slots to read.
355 *
356 * Return: 0 on success, <0 on failure.
357 */
358int mei_irq_read_handler(struct mei_device *dev,
359 struct list_head *cmpl_list, s32 *slots)
360{
361 struct mei_msg_hdr *mei_hdr;
362 struct mei_ext_meta_hdr *meta_hdr = NULL;
363 struct mei_cl *cl;
364 int ret;
365 u32 hdr_size_left;
366 u32 hdr_size_ext;
367 int i;
368 int ext_hdr_end;
369
370 if (!dev->rd_msg_hdr[0]) {
371 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
372 dev->rd_msg_hdr_count = 1;
373 (*slots)--;
374 dev_dbg(&dev->dev, "slots =%08x.\n", *slots);
375
376 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
377 if (ret) {
378 dev_err(&dev->dev, "corrupted message header 0x%08X\n",
379 dev->rd_msg_hdr[0]);
380 goto end;
381 }
382 }
383
384 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
385 dev_dbg(&dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
386
387 if (mei_slots2data(*slots) < mei_hdr->length) {
388 dev_err(&dev->dev, "less data available than length=%08x.\n",
389 *slots);
390 /* we can't read the message */
391 ret = -ENODATA;
392 goto end;
393 }
394
395 ext_hdr_end = 1;
396 hdr_size_left = mei_hdr->length;
397
398 if (mei_hdr->extended) {
399 if (!dev->rd_msg_hdr[1]) {
400 dev->rd_msg_hdr[1] = mei_read_hdr(dev);
401 dev->rd_msg_hdr_count++;
402 (*slots)--;
403 dev_dbg(&dev->dev, "extended header is %08x\n", dev->rd_msg_hdr[1]);
404 }
405 meta_hdr = ((struct mei_ext_meta_hdr *)&dev->rd_msg_hdr[1]);
406 if (check_add_overflow((u32)sizeof(*meta_hdr),
407 mei_slots2data(meta_hdr->size),
408 &hdr_size_ext)) {
409 dev_err(&dev->dev, "extended message size too big %d\n",
410 meta_hdr->size);
411 return -EBADMSG;
412 }
413 if (hdr_size_left < hdr_size_ext) {
414 dev_err(&dev->dev, "corrupted message header len %d\n",
415 mei_hdr->length);
416 return -EBADMSG;
417 }
418 hdr_size_left -= hdr_size_ext;
419
420 ext_hdr_end = meta_hdr->size + 2;
421 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
422 dev->rd_msg_hdr[i] = mei_read_hdr(dev);
423 dev_dbg(&dev->dev, "extended header %d is %08x\n", i,
424 dev->rd_msg_hdr[i]);
425 dev->rd_msg_hdr_count++;
426 (*slots)--;
427 }
428 }
429
430 if (mei_hdr->dma_ring) {
431 if (hdr_size_left != sizeof(dev->rd_msg_hdr[ext_hdr_end])) {
432 dev_err(&dev->dev, "corrupted message header len %d\n",
433 mei_hdr->length);
434 return -EBADMSG;
435 }
436
437 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
438 dev->rd_msg_hdr_count++;
439 (*slots)--;
440 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
441 }
442
443 /* HBM message */
444 if (hdr_is_hbm(mei_hdr)) {
445 ret = mei_hbm_dispatch(dev, mei_hdr);
446 if (ret) {
447 dev_dbg(&dev->dev, "mei_hbm_dispatch failed ret = %d\n", ret);
448 goto end;
449 }
450 goto reset_slots;
451 }
452
453 /* find recipient cl */
454 list_for_each_entry(cl, &dev->file_list, link) {
455 if (mei_cl_hbm_equal(cl, mei_hdr)) {
456 cl_dbg(dev, cl, "got a message\n");
457 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
458 goto reset_slots;
459 }
460 }
461
462 /* if no recipient cl was found we assume corrupted header */
463 /* A message for not connected fixed address clients
464 * should be silently discarded
465 * On power down client may be force cleaned,
466 * silently discard such messages
467 */
468 if (hdr_is_fixed(mei_hdr) ||
469 dev->dev_state == MEI_DEV_POWER_DOWN) {
470 mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
471 ret = 0;
472 goto reset_slots;
473 }
474 dev_err(&dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]);
475 ret = -EBADMSG;
476 goto end;
477
478reset_slots:
479 /* reset the number of slots and header */
480 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
481 dev->rd_msg_hdr_count = 0;
482 *slots = mei_count_full_read_slots(dev);
483 if (*slots == -EOVERFLOW) {
484 /* overflow - reset */
485 dev_err(&dev->dev, "resetting due to slots overflow.\n");
486 /* set the event since message has been read */
487 ret = -ERANGE;
488 goto end;
489 }
490end:
491 return ret;
492}
493EXPORT_SYMBOL_GPL(mei_irq_read_handler);
494
495
496/**
497 * mei_irq_write_handler - dispatch write requests
498 * after irq received
499 *
500 * @dev: the device structure
501 * @cmpl_list: An instance of our list structure
502 *
503 * Return: 0 on success, <0 on failure.
504 */
505int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
506{
507
508 struct mei_cl *cl;
509 struct mei_cl_cb *cb, *next;
510 s32 slots;
511 int ret;
512
513
514 if (!mei_hbuf_acquire(dev))
515 return 0;
516
517 slots = mei_hbuf_empty_slots(dev);
518 if (slots < 0)
519 return -EOVERFLOW;
520
521 if (slots == 0)
522 return -EMSGSIZE;
523
524 /* complete all waiting for write CB */
525 dev_dbg(&dev->dev, "complete all waiting for write cb.\n");
526
527 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
528 cl = cb->cl;
529
530 cl->status = 0;
531 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
532 cl->writing_state = MEI_WRITE_COMPLETE;
533 list_move_tail(&cb->list, cmpl_list);
534 }
535
536 /* complete control write list CB */
537 dev_dbg(&dev->dev, "complete control write list cb.\n");
538 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
539 cl = cb->cl;
540 switch (cb->fop_type) {
541 case MEI_FOP_DISCONNECT:
542 /* send disconnect message */
543 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
544 if (ret)
545 return ret;
546
547 break;
548 case MEI_FOP_READ:
549 /* send flow control message */
550 ret = mei_cl_irq_read(cl, cb, cmpl_list);
551 if (ret)
552 return ret;
553
554 break;
555 case MEI_FOP_CONNECT:
556 /* connect message */
557 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
558 if (ret)
559 return ret;
560
561 break;
562 case MEI_FOP_DISCONNECT_RSP:
563 /* send disconnect resp */
564 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
565 if (ret)
566 return ret;
567 break;
568
569 case MEI_FOP_NOTIFY_START:
570 case MEI_FOP_NOTIFY_STOP:
571 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
572 if (ret)
573 return ret;
574 break;
575 case MEI_FOP_DMA_MAP:
576 ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
577 if (ret)
578 return ret;
579 break;
580 case MEI_FOP_DMA_UNMAP:
581 ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
582 if (ret)
583 return ret;
584 break;
585 default:
586 BUG();
587 }
588
589 }
590 /* complete write list CB */
591 dev_dbg(&dev->dev, "complete write list cb.\n");
592 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
593 cl = cb->cl;
594 ret = mei_cl_irq_write(cl, cb, cmpl_list);
595 if (ret)
596 return ret;
597 }
598 return 0;
599}
600EXPORT_SYMBOL_GPL(mei_irq_write_handler);
601
602
603/**
604 * mei_connect_timeout - connect/disconnect timeouts
605 *
606 * @cl: host client
607 */
608static void mei_connect_timeout(struct mei_cl *cl)
609{
610 struct mei_device *dev = cl->dev;
611
612 if (cl->state == MEI_FILE_CONNECTING) {
613 if (dev->hbm_f_dot_supported) {
614 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
615 wake_up(&cl->wait);
616 return;
617 }
618 }
619 mei_reset(dev);
620}
621
622#define MEI_STALL_TIMER_FREQ (2 * HZ)
623/**
624 * mei_schedule_stall_timer - re-arm stall_timer work
625 *
626 * @dev: the device structure
627 *
628 * Schedule stall timer
629 */
630void mei_schedule_stall_timer(struct mei_device *dev)
631{
632 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
633}
634
635/**
636 * mei_timer - timer function.
637 *
638 * @work: pointer to the work_struct structure
639 *
640 */
641void mei_timer(struct work_struct *work)
642{
643 struct mei_cl *cl;
644 struct mei_device *dev = container_of(work,
645 struct mei_device, timer_work.work);
646 bool reschedule_timer = false;
647
648 mutex_lock(&dev->device_lock);
649
650 /* Catch interrupt stalls during HBM init handshake */
651 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
652 dev->hbm_state != MEI_HBM_IDLE) {
653
654 if (dev->init_clients_timer) {
655 if (--dev->init_clients_timer == 0) {
656 dev_err(&dev->dev, "timer: init clients timeout hbm_state = %d.\n",
657 dev->hbm_state);
658 mei_reset(dev);
659 goto out;
660 }
661 reschedule_timer = true;
662 }
663 }
664
665 if (dev->dev_state != MEI_DEV_ENABLED)
666 goto out;
667
668 /*** connect/disconnect timeouts ***/
669 list_for_each_entry(cl, &dev->file_list, link) {
670 if (cl->timer_count) {
671 if (--cl->timer_count == 0) {
672 dev_err(&dev->dev, "timer: connect/disconnect timeout.\n");
673 mei_connect_timeout(cl);
674 goto out;
675 }
676 reschedule_timer = true;
677 }
678 }
679
680out:
681 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
682 mei_schedule_stall_timer(dev);
683
684 mutex_unlock(&dev->device_lock);
685}