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 list_move_tail(&cb->list, &cl->rd_pending);
281
282 return 0;
283 }
284
hdr_is_hbm(struct mei_msg_hdr * mei_hdr)285 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
286 {
287 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
288 }
289
hdr_is_fixed(struct mei_msg_hdr * mei_hdr)290 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
291 {
292 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
293 }
294
hdr_is_valid(u32 msg_hdr)295 static inline int hdr_is_valid(u32 msg_hdr)
296 {
297 struct mei_msg_hdr *mei_hdr;
298
299 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
300 if (!msg_hdr || mei_hdr->reserved)
301 return -EBADMSG;
302
303 if (mei_hdr->dma_ring && mei_hdr->length != MEI_SLOT_SIZE)
304 return -EBADMSG;
305
306 return 0;
307 }
308
309 /**
310 * mei_irq_read_handler - bottom half read routine after ISR to
311 * handle the read processing.
312 *
313 * @dev: the device structure
314 * @cmpl_list: An instance of our list structure
315 * @slots: slots to read.
316 *
317 * Return: 0 on success, <0 on failure.
318 */
mei_irq_read_handler(struct mei_device * dev,struct list_head * cmpl_list,s32 * slots)319 int mei_irq_read_handler(struct mei_device *dev,
320 struct list_head *cmpl_list, s32 *slots)
321 {
322 struct mei_msg_hdr *mei_hdr;
323 struct mei_ext_meta_hdr *meta_hdr = NULL;
324 struct mei_cl *cl;
325 int ret;
326 u32 ext_meta_hdr_u32;
327 int i;
328 int ext_hdr_end;
329
330 if (!dev->rd_msg_hdr[0]) {
331 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
332 dev->rd_msg_hdr_count = 1;
333 (*slots)--;
334 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
335
336 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
337 if (ret) {
338 dev_err(dev->dev, "corrupted message header 0x%08X\n",
339 dev->rd_msg_hdr[0]);
340 goto end;
341 }
342 }
343
344 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
345 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
346
347 if (mei_slots2data(*slots) < mei_hdr->length) {
348 dev_err(dev->dev, "less data available than length=%08x.\n",
349 *slots);
350 /* we can't read the message */
351 ret = -ENODATA;
352 goto end;
353 }
354
355 ext_hdr_end = 1;
356
357 if (mei_hdr->extended) {
358 if (!dev->rd_msg_hdr[1]) {
359 ext_meta_hdr_u32 = mei_read_hdr(dev);
360 dev->rd_msg_hdr[1] = ext_meta_hdr_u32;
361 dev->rd_msg_hdr_count++;
362 (*slots)--;
363 dev_dbg(dev->dev, "extended header is %08x\n",
364 ext_meta_hdr_u32);
365 }
366 meta_hdr = ((struct mei_ext_meta_hdr *)
367 dev->rd_msg_hdr + 1);
368 ext_hdr_end = meta_hdr->size + 2;
369 for (i = dev->rd_msg_hdr_count; i < ext_hdr_end; i++) {
370 dev->rd_msg_hdr[i] = mei_read_hdr(dev);
371 dev_dbg(dev->dev, "extended header %d is %08x\n", i,
372 dev->rd_msg_hdr[i]);
373 dev->rd_msg_hdr_count++;
374 (*slots)--;
375 }
376 }
377
378 if (mei_hdr->dma_ring) {
379 dev->rd_msg_hdr[ext_hdr_end] = mei_read_hdr(dev);
380 dev->rd_msg_hdr_count++;
381 (*slots)--;
382 mei_hdr->length -= sizeof(dev->rd_msg_hdr[ext_hdr_end]);
383 }
384
385 /* HBM message */
386 if (hdr_is_hbm(mei_hdr)) {
387 ret = mei_hbm_dispatch(dev, mei_hdr);
388 if (ret) {
389 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
390 ret);
391 goto end;
392 }
393 goto reset_slots;
394 }
395
396 /* find recipient cl */
397 list_for_each_entry(cl, &dev->file_list, link) {
398 if (mei_cl_hbm_equal(cl, mei_hdr)) {
399 cl_dbg(dev, cl, "got a message\n");
400 break;
401 }
402 }
403
404 /* if no recipient cl was found we assume corrupted header */
405 if (&cl->link == &dev->file_list) {
406 /* A message for not connected fixed address clients
407 * should be silently discarded
408 * On power down client may be force cleaned,
409 * silently discard such messages
410 */
411 if (hdr_is_fixed(mei_hdr) ||
412 dev->dev_state == MEI_DEV_POWER_DOWN) {
413 mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length);
414 ret = 0;
415 goto reset_slots;
416 }
417 dev_err(dev->dev, "no destination client found 0x%08X\n",
418 dev->rd_msg_hdr[0]);
419 ret = -EBADMSG;
420 goto end;
421 }
422
423 ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list);
424
425
426 reset_slots:
427 /* reset the number of slots and header */
428 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
429 dev->rd_msg_hdr_count = 0;
430 *slots = mei_count_full_read_slots(dev);
431 if (*slots == -EOVERFLOW) {
432 /* overflow - reset */
433 dev_err(dev->dev, "resetting due to slots overflow.\n");
434 /* set the event since message has been read */
435 ret = -ERANGE;
436 goto end;
437 }
438 end:
439 return ret;
440 }
441 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
442
443
444 /**
445 * mei_irq_write_handler - dispatch write requests
446 * after irq received
447 *
448 * @dev: the device structure
449 * @cmpl_list: An instance of our list structure
450 *
451 * Return: 0 on success, <0 on failure.
452 */
mei_irq_write_handler(struct mei_device * dev,struct list_head * cmpl_list)453 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
454 {
455
456 struct mei_cl *cl;
457 struct mei_cl_cb *cb, *next;
458 s32 slots;
459 int ret;
460
461
462 if (!mei_hbuf_acquire(dev))
463 return 0;
464
465 slots = mei_hbuf_empty_slots(dev);
466 if (slots < 0)
467 return -EOVERFLOW;
468
469 if (slots == 0)
470 return -EMSGSIZE;
471
472 /* complete all waiting for write CB */
473 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
474
475 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
476 cl = cb->cl;
477
478 cl->status = 0;
479 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
480 cl->writing_state = MEI_WRITE_COMPLETE;
481 list_move_tail(&cb->list, cmpl_list);
482 }
483
484 /* complete control write list CB */
485 dev_dbg(dev->dev, "complete control write list cb.\n");
486 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
487 cl = cb->cl;
488 switch (cb->fop_type) {
489 case MEI_FOP_DISCONNECT:
490 /* send disconnect message */
491 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
492 if (ret)
493 return ret;
494
495 break;
496 case MEI_FOP_READ:
497 /* send flow control message */
498 ret = mei_cl_irq_read(cl, cb, cmpl_list);
499 if (ret)
500 return ret;
501
502 break;
503 case MEI_FOP_CONNECT:
504 /* connect message */
505 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
506 if (ret)
507 return ret;
508
509 break;
510 case MEI_FOP_DISCONNECT_RSP:
511 /* send disconnect resp */
512 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
513 if (ret)
514 return ret;
515 break;
516
517 case MEI_FOP_NOTIFY_START:
518 case MEI_FOP_NOTIFY_STOP:
519 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
520 if (ret)
521 return ret;
522 break;
523 default:
524 BUG();
525 }
526
527 }
528 /* complete write list CB */
529 dev_dbg(dev->dev, "complete write list cb.\n");
530 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
531 cl = cb->cl;
532 ret = mei_cl_irq_write(cl, cb, cmpl_list);
533 if (ret)
534 return ret;
535 }
536 return 0;
537 }
538 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
539
540
541 /**
542 * mei_connect_timeout - connect/disconnect timeouts
543 *
544 * @cl: host client
545 */
mei_connect_timeout(struct mei_cl * cl)546 static void mei_connect_timeout(struct mei_cl *cl)
547 {
548 struct mei_device *dev = cl->dev;
549
550 if (cl->state == MEI_FILE_CONNECTING) {
551 if (dev->hbm_f_dot_supported) {
552 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
553 wake_up(&cl->wait);
554 return;
555 }
556 }
557 mei_reset(dev);
558 }
559
560 #define MEI_STALL_TIMER_FREQ (2 * HZ)
561 /**
562 * mei_schedule_stall_timer - re-arm stall_timer work
563 *
564 * Schedule stall timer
565 *
566 * @dev: the device structure
567 */
mei_schedule_stall_timer(struct mei_device * dev)568 void mei_schedule_stall_timer(struct mei_device *dev)
569 {
570 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
571 }
572
573 /**
574 * mei_timer - timer function.
575 *
576 * @work: pointer to the work_struct structure
577 *
578 */
mei_timer(struct work_struct * work)579 void mei_timer(struct work_struct *work)
580 {
581 struct mei_cl *cl;
582 struct mei_device *dev = container_of(work,
583 struct mei_device, timer_work.work);
584 bool reschedule_timer = false;
585
586 mutex_lock(&dev->device_lock);
587
588 /* Catch interrupt stalls during HBM init handshake */
589 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
590 dev->hbm_state != MEI_HBM_IDLE) {
591
592 if (dev->init_clients_timer) {
593 if (--dev->init_clients_timer == 0) {
594 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
595 dev->hbm_state);
596 mei_reset(dev);
597 goto out;
598 }
599 reschedule_timer = true;
600 }
601 }
602
603 if (dev->dev_state != MEI_DEV_ENABLED)
604 goto out;
605
606 /*** connect/disconnect timeouts ***/
607 list_for_each_entry(cl, &dev->file_list, link) {
608 if (cl->timer_count) {
609 if (--cl->timer_count == 0) {
610 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
611 mei_connect_timeout(cl);
612 goto out;
613 }
614 reschedule_timer = true;
615 }
616 }
617
618 out:
619 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
620 mei_schedule_stall_timer(dev);
621
622 mutex_unlock(&dev->device_lock);
623 }
624
