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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 dev_dbg(dev->dev, "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 */
65static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
66{
67 if (hdr->dma_ring)
68 mei_dma_ring_read(dev, NULL, hdr->extension[0]);
69 /*
70 * no need to check for size as it is guarantied
71 * that length fits into rd_msg_buf
72 */
73 mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
74 dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
75 MEI_HDR_PRM(hdr));
76}
77
78/**
79 * mei_cl_irq_read_msg - process client message
80 *
81 * @cl: reading client
82 * @mei_hdr: header of mei client message
83 * @cmpl_list: completion list
84 *
85 * Return: always 0
86 */
87static int mei_cl_irq_read_msg(struct mei_cl *cl,
88 struct mei_msg_hdr *mei_hdr,
89 struct list_head *cmpl_list)
90{
91 struct mei_device *dev = cl->dev;
92 struct mei_cl_cb *cb;
93 size_t buf_sz;
94 u32 length;
95
96 cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
97 if (!cb) {
98 if (!mei_cl_is_fixed_address(cl)) {
99 cl_err(dev, cl, "pending read cb not found\n");
100 goto discard;
101 }
102 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
103 if (!cb)
104 goto discard;
105 list_add_tail(&cb->list, &cl->rd_pending);
106 }
107
108 if (!mei_cl_is_connected(cl)) {
109 cl_dbg(dev, cl, "not connected\n");
110 cb->status = -ENODEV;
111 goto discard;
112 }
113
114 length = mei_hdr->dma_ring ? mei_hdr->extension[0] : mei_hdr->length;
115
116 buf_sz = length + cb->buf_idx;
117 /* catch for integer overflow */
118 if (buf_sz < cb->buf_idx) {
119 cl_err(dev, cl, "message is too big len %d idx %zu\n",
120 length, cb->buf_idx);
121 cb->status = -EMSGSIZE;
122 goto discard;
123 }
124
125 if (cb->buf.size < buf_sz) {
126 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
127 cb->buf.size, length, cb->buf_idx);
128 cb->status = -EMSGSIZE;
129 goto discard;
130 }
131
132 if (mei_hdr->dma_ring)
133 mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
134
135 /* for DMA read 0 length to generate an interrupt to the device */
136 mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
137
138 cb->buf_idx += length;
139
140 if (mei_hdr->msg_complete) {
141 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
142 list_move_tail(&cb->list, cmpl_list);
143 } else {
144 pm_runtime_mark_last_busy(dev->dev);
145 pm_request_autosuspend(dev->dev);
146 }
147
148 return 0;
149
150discard:
151 if (cb)
152 list_move_tail(&cb->list, cmpl_list);
153 mei_irq_discard_msg(dev, mei_hdr);
154 return 0;
155}
156
157/**
158 * mei_cl_irq_disconnect_rsp - send disconnection response message
159 *
160 * @cl: client
161 * @cb: callback block.
162 * @cmpl_list: complete list.
163 *
164 * Return: 0, OK; otherwise, error.
165 */
166static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
167 struct list_head *cmpl_list)
168{
169 struct mei_device *dev = cl->dev;
170 u32 msg_slots;
171 int slots;
172 int ret;
173
174 msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_response));
175 slots = mei_hbuf_empty_slots(dev);
176 if (slots < 0)
177 return -EOVERFLOW;
178
179 if ((u32)slots < msg_slots)
180 return -EMSGSIZE;
181
182 ret = mei_hbm_cl_disconnect_rsp(dev, cl);
183 list_move_tail(&cb->list, cmpl_list);
184
185 return ret;
186}
187
188/**
189 * mei_cl_irq_read - processes client read related operation from the
190 * interrupt thread context - request for flow control credits
191 *
192 * @cl: client
193 * @cb: callback block.
194 * @cmpl_list: complete list.
195 *
196 * Return: 0, OK; otherwise, error.
197 */
198static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
199 struct list_head *cmpl_list)
200{
201 struct mei_device *dev = cl->dev;
202 u32 msg_slots;
203 int slots;
204 int ret;
205
206 if (!list_empty(&cl->rd_pending))
207 return 0;
208
209 msg_slots = mei_hbm2slots(sizeof(struct hbm_flow_control));
210 slots = mei_hbuf_empty_slots(dev);
211 if (slots < 0)
212 return -EOVERFLOW;
213
214 if ((u32)slots < msg_slots)
215 return -EMSGSIZE;
216
217 ret = mei_hbm_cl_flow_control_req(dev, cl);
218 if (ret) {
219 cl->status = ret;
220 cb->buf_idx = 0;
221 list_move_tail(&cb->list, cmpl_list);
222 return ret;
223 }
224
225 list_move_tail(&cb->list, &cl->rd_pending);
226
227 return 0;
228}
229
230static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
231{
232 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
233}
234
235static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
236{
237 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
238}
239
240static inline int hdr_is_valid(u32 msg_hdr)
241{
242 struct mei_msg_hdr *mei_hdr;
243
244 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
245 if (!msg_hdr || mei_hdr->reserved)
246 return -EBADMSG;
247
248 if (mei_hdr->dma_ring && mei_hdr->length != MEI_SLOT_SIZE)
249 return -EBADMSG;
250
251 return 0;
252}
253
254/**
255 * mei_irq_read_handler - bottom half read routine after ISR to
256 * handle the read processing.
257 *
258 * @dev: the device structure
259 * @cmpl_list: An instance of our list structure
260 * @slots: slots to read.
261 *
262 * Return: 0 on success, <0 on failure.
263 */
264int mei_irq_read_handler(struct mei_device *dev,
265 struct list_head *cmpl_list, s32 *slots)
266{
267 struct mei_msg_hdr *mei_hdr;
268 struct mei_cl *cl;
269 int ret;
270
271 if (!dev->rd_msg_hdr[0]) {
272 dev->rd_msg_hdr[0] = mei_read_hdr(dev);
273 (*slots)--;
274 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
275
276 ret = hdr_is_valid(dev->rd_msg_hdr[0]);
277 if (ret) {
278 dev_err(dev->dev, "corrupted message header 0x%08X\n",
279 dev->rd_msg_hdr[0]);
280 goto end;
281 }
282 }
283
284 mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
285 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
286
287 if (mei_slots2data(*slots) < mei_hdr->length) {
288 dev_err(dev->dev, "less data available than length=%08x.\n",
289 *slots);
290 /* we can't read the message */
291 ret = -ENODATA;
292 goto end;
293 }
294
295 if (mei_hdr->dma_ring) {
296 dev->rd_msg_hdr[1] = mei_read_hdr(dev);
297 (*slots)--;
298 mei_hdr->length = 0;
299 }
300
301 /* HBM message */
302 if (hdr_is_hbm(mei_hdr)) {
303 ret = mei_hbm_dispatch(dev, mei_hdr);
304 if (ret) {
305 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
306 ret);
307 goto end;
308 }
309 goto reset_slots;
310 }
311
312 /* find recipient cl */
313 list_for_each_entry(cl, &dev->file_list, link) {
314 if (mei_cl_hbm_equal(cl, mei_hdr)) {
315 cl_dbg(dev, cl, "got a message\n");
316 break;
317 }
318 }
319
320 /* if no recipient cl was found we assume corrupted header */
321 if (&cl->link == &dev->file_list) {
322 /* A message for not connected fixed address clients
323 * should be silently discarded
324 * On power down client may be force cleaned,
325 * silently discard such messages
326 */
327 if (hdr_is_fixed(mei_hdr) ||
328 dev->dev_state == MEI_DEV_POWER_DOWN) {
329 mei_irq_discard_msg(dev, mei_hdr);
330 ret = 0;
331 goto reset_slots;
332 }
333 dev_err(dev->dev, "no destination client found 0x%08X\n",
334 dev->rd_msg_hdr[0]);
335 ret = -EBADMSG;
336 goto end;
337 }
338
339 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
340
341
342reset_slots:
343 /* reset the number of slots and header */
344 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
345 *slots = mei_count_full_read_slots(dev);
346 if (*slots == -EOVERFLOW) {
347 /* overflow - reset */
348 dev_err(dev->dev, "resetting due to slots overflow.\n");
349 /* set the event since message has been read */
350 ret = -ERANGE;
351 goto end;
352 }
353end:
354 return ret;
355}
356EXPORT_SYMBOL_GPL(mei_irq_read_handler);
357
358
359/**
360 * mei_irq_write_handler - dispatch write requests
361 * after irq received
362 *
363 * @dev: the device structure
364 * @cmpl_list: An instance of our list structure
365 *
366 * Return: 0 on success, <0 on failure.
367 */
368int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
369{
370
371 struct mei_cl *cl;
372 struct mei_cl_cb *cb, *next;
373 s32 slots;
374 int ret;
375
376
377 if (!mei_hbuf_acquire(dev))
378 return 0;
379
380 slots = mei_hbuf_empty_slots(dev);
381 if (slots < 0)
382 return -EOVERFLOW;
383
384 if (slots == 0)
385 return -EMSGSIZE;
386
387 /* complete all waiting for write CB */
388 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
389
390 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
391 cl = cb->cl;
392
393 cl->status = 0;
394 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
395 cl->writing_state = MEI_WRITE_COMPLETE;
396 list_move_tail(&cb->list, cmpl_list);
397 }
398
399 /* complete control write list CB */
400 dev_dbg(dev->dev, "complete control write list cb.\n");
401 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
402 cl = cb->cl;
403 switch (cb->fop_type) {
404 case MEI_FOP_DISCONNECT:
405 /* send disconnect message */
406 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
407 if (ret)
408 return ret;
409
410 break;
411 case MEI_FOP_READ:
412 /* send flow control message */
413 ret = mei_cl_irq_read(cl, cb, cmpl_list);
414 if (ret)
415 return ret;
416
417 break;
418 case MEI_FOP_CONNECT:
419 /* connect message */
420 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
421 if (ret)
422 return ret;
423
424 break;
425 case MEI_FOP_DISCONNECT_RSP:
426 /* send disconnect resp */
427 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
428 if (ret)
429 return ret;
430 break;
431
432 case MEI_FOP_NOTIFY_START:
433 case MEI_FOP_NOTIFY_STOP:
434 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
435 if (ret)
436 return ret;
437 break;
438 default:
439 BUG();
440 }
441
442 }
443 /* complete write list CB */
444 dev_dbg(dev->dev, "complete write list cb.\n");
445 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
446 cl = cb->cl;
447 ret = mei_cl_irq_write(cl, cb, cmpl_list);
448 if (ret)
449 return ret;
450 }
451 return 0;
452}
453EXPORT_SYMBOL_GPL(mei_irq_write_handler);
454
455
456/**
457 * mei_connect_timeout - connect/disconnect timeouts
458 *
459 * @cl: host client
460 */
461static void mei_connect_timeout(struct mei_cl *cl)
462{
463 struct mei_device *dev = cl->dev;
464
465 if (cl->state == MEI_FILE_CONNECTING) {
466 if (dev->hbm_f_dot_supported) {
467 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
468 wake_up(&cl->wait);
469 return;
470 }
471 }
472 mei_reset(dev);
473}
474
475#define MEI_STALL_TIMER_FREQ (2 * HZ)
476/**
477 * mei_schedule_stall_timer - re-arm stall_timer work
478 *
479 * Schedule stall timer
480 *
481 * @dev: the device structure
482 */
483void mei_schedule_stall_timer(struct mei_device *dev)
484{
485 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
486}
487
488/**
489 * mei_timer - timer function.
490 *
491 * @work: pointer to the work_struct structure
492 *
493 */
494void mei_timer(struct work_struct *work)
495{
496 struct mei_cl *cl;
497 struct mei_device *dev = container_of(work,
498 struct mei_device, timer_work.work);
499 bool reschedule_timer = false;
500
501 mutex_lock(&dev->device_lock);
502
503 /* Catch interrupt stalls during HBM init handshake */
504 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
505 dev->hbm_state != MEI_HBM_IDLE) {
506
507 if (dev->init_clients_timer) {
508 if (--dev->init_clients_timer == 0) {
509 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
510 dev->hbm_state);
511 mei_reset(dev);
512 goto out;
513 }
514 reschedule_timer = true;
515 }
516 }
517
518 if (dev->dev_state != MEI_DEV_ENABLED)
519 goto out;
520
521 /*** connect/disconnect timeouts ***/
522 list_for_each_entry(cl, &dev->file_list, link) {
523 if (cl->timer_count) {
524 if (--cl->timer_count == 0) {
525 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
526 mei_connect_timeout(cl);
527 goto out;
528 }
529 reschedule_timer = true;
530 }
531 }
532
533out:
534 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
535 mei_schedule_stall_timer(dev);
536
537 mutex_unlock(&dev->device_lock);
538}