1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2016-2019 Intel Corporation
4 */
5
6 #include "i915_drv.h"
7 #include "intel_guc_ct.h"
8
9 #ifdef CONFIG_DRM_I915_DEBUG_GUC
10 #define CT_DEBUG_DRIVER(...) DRM_DEBUG_DRIVER(__VA_ARGS__)
11 #else
12 #define CT_DEBUG_DRIVER(...) do { } while (0)
13 #endif
14
15 struct ct_request {
16 struct list_head link;
17 u32 fence;
18 u32 status;
19 u32 response_len;
20 u32 *response_buf;
21 };
22
23 struct ct_incoming_request {
24 struct list_head link;
25 u32 msg[];
26 };
27
28 enum { CTB_SEND = 0, CTB_RECV = 1 };
29
30 enum { CTB_OWNER_HOST = 0 };
31
32 static void ct_incoming_request_worker_func(struct work_struct *w);
33
34 /**
35 * intel_guc_ct_init_early - Initialize CT state without requiring device access
36 * @ct: pointer to CT struct
37 */
intel_guc_ct_init_early(struct intel_guc_ct * ct)38 void intel_guc_ct_init_early(struct intel_guc_ct *ct)
39 {
40 /* we're using static channel owners */
41 ct->host_channel.owner = CTB_OWNER_HOST;
42
43 spin_lock_init(&ct->lock);
44 INIT_LIST_HEAD(&ct->pending_requests);
45 INIT_LIST_HEAD(&ct->incoming_requests);
46 INIT_WORK(&ct->worker, ct_incoming_request_worker_func);
47 }
48
ct_to_guc(struct intel_guc_ct * ct)49 static inline struct intel_guc *ct_to_guc(struct intel_guc_ct *ct)
50 {
51 return container_of(ct, struct intel_guc, ct);
52 }
53
guc_ct_buffer_type_to_str(u32 type)54 static inline const char *guc_ct_buffer_type_to_str(u32 type)
55 {
56 switch (type) {
57 case INTEL_GUC_CT_BUFFER_TYPE_SEND:
58 return "SEND";
59 case INTEL_GUC_CT_BUFFER_TYPE_RECV:
60 return "RECV";
61 default:
62 return "<invalid>";
63 }
64 }
65
guc_ct_buffer_desc_init(struct guc_ct_buffer_desc * desc,u32 cmds_addr,u32 size,u32 owner)66 static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
67 u32 cmds_addr, u32 size, u32 owner)
68 {
69 CT_DEBUG_DRIVER("CT: desc %p init addr=%#x size=%u owner=%u\n",
70 desc, cmds_addr, size, owner);
71 memset(desc, 0, sizeof(*desc));
72 desc->addr = cmds_addr;
73 desc->size = size;
74 desc->owner = owner;
75 }
76
guc_ct_buffer_desc_reset(struct guc_ct_buffer_desc * desc)77 static void guc_ct_buffer_desc_reset(struct guc_ct_buffer_desc *desc)
78 {
79 CT_DEBUG_DRIVER("CT: desc %p reset head=%u tail=%u\n",
80 desc, desc->head, desc->tail);
81 desc->head = 0;
82 desc->tail = 0;
83 desc->is_in_error = 0;
84 }
85
guc_action_register_ct_buffer(struct intel_guc * guc,u32 desc_addr,u32 type)86 static int guc_action_register_ct_buffer(struct intel_guc *guc,
87 u32 desc_addr,
88 u32 type)
89 {
90 u32 action[] = {
91 INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER,
92 desc_addr,
93 sizeof(struct guc_ct_buffer_desc),
94 type
95 };
96 int err;
97
98 /* Can't use generic send(), CT registration must go over MMIO */
99 err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0);
100 if (err)
101 DRM_ERROR("CT: register %s buffer failed; err=%d\n",
102 guc_ct_buffer_type_to_str(type), err);
103 return err;
104 }
105
guc_action_deregister_ct_buffer(struct intel_guc * guc,u32 owner,u32 type)106 static int guc_action_deregister_ct_buffer(struct intel_guc *guc,
107 u32 owner,
108 u32 type)
109 {
110 u32 action[] = {
111 INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER,
112 owner,
113 type
114 };
115 int err;
116
117 /* Can't use generic send(), CT deregistration must go over MMIO */
118 err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0);
119 if (err)
120 DRM_ERROR("CT: deregister %s buffer failed; owner=%d err=%d\n",
121 guc_ct_buffer_type_to_str(type), owner, err);
122 return err;
123 }
124
ctch_init(struct intel_guc * guc,struct intel_guc_ct_channel * ctch)125 static int ctch_init(struct intel_guc *guc,
126 struct intel_guc_ct_channel *ctch)
127 {
128 struct i915_vma *vma;
129 void *blob;
130 int err;
131 int i;
132
133 GEM_BUG_ON(ctch->vma);
134
135 /* We allocate 1 page to hold both descriptors and both buffers.
136 * ___________.....................
137 * |desc (SEND)| :
138 * |___________| PAGE/4
139 * :___________....................:
140 * |desc (RECV)| :
141 * |___________| PAGE/4
142 * :_______________________________:
143 * |cmds (SEND) |
144 * | PAGE/4
145 * |_______________________________|
146 * |cmds (RECV) |
147 * | PAGE/4
148 * |_______________________________|
149 *
150 * Each message can use a maximum of 32 dwords and we don't expect to
151 * have more than 1 in flight at any time, so we have enough space.
152 * Some logic further ahead will rely on the fact that there is only 1
153 * page and that it is always mapped, so if the size is changed the
154 * other code will need updating as well.
155 */
156
157 /* allocate vma */
158 vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
159 if (IS_ERR(vma)) {
160 err = PTR_ERR(vma);
161 goto err_out;
162 }
163 ctch->vma = vma;
164
165 /* map first page */
166 blob = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
167 if (IS_ERR(blob)) {
168 err = PTR_ERR(blob);
169 goto err_vma;
170 }
171 CT_DEBUG_DRIVER("CT: vma base=%#x\n",
172 intel_guc_ggtt_offset(guc, ctch->vma));
173
174 /* store pointers to desc and cmds */
175 for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
176 GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
177 ctch->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
178 ctch->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
179 }
180
181 return 0;
182
183 err_vma:
184 i915_vma_unpin_and_release(&ctch->vma, 0);
185 err_out:
186 CT_DEBUG_DRIVER("CT: channel %d initialization failed; err=%d\n",
187 ctch->owner, err);
188 return err;
189 }
190
ctch_fini(struct intel_guc * guc,struct intel_guc_ct_channel * ctch)191 static void ctch_fini(struct intel_guc *guc,
192 struct intel_guc_ct_channel *ctch)
193 {
194 GEM_BUG_ON(ctch->enabled);
195
196 i915_vma_unpin_and_release(&ctch->vma, I915_VMA_RELEASE_MAP);
197 }
198
ctch_enable(struct intel_guc * guc,struct intel_guc_ct_channel * ctch)199 static int ctch_enable(struct intel_guc *guc,
200 struct intel_guc_ct_channel *ctch)
201 {
202 u32 base;
203 int err;
204 int i;
205
206 GEM_BUG_ON(!ctch->vma);
207
208 GEM_BUG_ON(ctch->enabled);
209
210 /* vma should be already allocated and map'ed */
211 base = intel_guc_ggtt_offset(guc, ctch->vma);
212
213 /* (re)initialize descriptors
214 * cmds buffers are in the second half of the blob page
215 */
216 for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
217 GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
218 guc_ct_buffer_desc_init(ctch->ctbs[i].desc,
219 base + PAGE_SIZE/4 * i + PAGE_SIZE/2,
220 PAGE_SIZE/4,
221 ctch->owner);
222 }
223
224 /* register buffers, starting wirh RECV buffer
225 * descriptors are in first half of the blob
226 */
227 err = guc_action_register_ct_buffer(guc,
228 base + PAGE_SIZE/4 * CTB_RECV,
229 INTEL_GUC_CT_BUFFER_TYPE_RECV);
230 if (unlikely(err))
231 goto err_out;
232
233 err = guc_action_register_ct_buffer(guc,
234 base + PAGE_SIZE/4 * CTB_SEND,
235 INTEL_GUC_CT_BUFFER_TYPE_SEND);
236 if (unlikely(err))
237 goto err_deregister;
238
239 ctch->enabled = true;
240
241 return 0;
242
243 err_deregister:
244 guc_action_deregister_ct_buffer(guc,
245 ctch->owner,
246 INTEL_GUC_CT_BUFFER_TYPE_RECV);
247 err_out:
248 DRM_ERROR("CT: can't open channel %d; err=%d\n", ctch->owner, err);
249 return err;
250 }
251
ctch_disable(struct intel_guc * guc,struct intel_guc_ct_channel * ctch)252 static void ctch_disable(struct intel_guc *guc,
253 struct intel_guc_ct_channel *ctch)
254 {
255 GEM_BUG_ON(!ctch->enabled);
256
257 ctch->enabled = false;
258
259 guc_action_deregister_ct_buffer(guc,
260 ctch->owner,
261 INTEL_GUC_CT_BUFFER_TYPE_SEND);
262 guc_action_deregister_ct_buffer(guc,
263 ctch->owner,
264 INTEL_GUC_CT_BUFFER_TYPE_RECV);
265 }
266
ctch_get_next_fence(struct intel_guc_ct_channel * ctch)267 static u32 ctch_get_next_fence(struct intel_guc_ct_channel *ctch)
268 {
269 /* For now it's trivial */
270 return ++ctch->next_fence;
271 }
272
273 /**
274 * DOC: CTB Host to GuC request
275 *
276 * Format of the CTB Host to GuC request message is as follows::
277 *
278 * +------------+---------+---------+---------+---------+
279 * | msg[0] | [1] | [2] | ... | [n-1] |
280 * +------------+---------+---------+---------+---------+
281 * | MESSAGE | MESSAGE PAYLOAD |
282 * + HEADER +---------+---------+---------+---------+
283 * | | 0 | 1 | ... | n |
284 * +============+=========+=========+=========+=========+
285 * | len >= 1 | FENCE | request specific data |
286 * +------+-----+---------+---------+---------+---------+
287 *
288 * ^-----------------len-------------------^
289 */
290
ctb_write(struct intel_guc_ct_buffer * ctb,const u32 * action,u32 len,u32 fence,bool want_response)291 static int ctb_write(struct intel_guc_ct_buffer *ctb,
292 const u32 *action,
293 u32 len /* in dwords */,
294 u32 fence,
295 bool want_response)
296 {
297 struct guc_ct_buffer_desc *desc = ctb->desc;
298 u32 head = desc->head / 4; /* in dwords */
299 u32 tail = desc->tail / 4; /* in dwords */
300 u32 size = desc->size / 4; /* in dwords */
301 u32 used; /* in dwords */
302 u32 header;
303 u32 *cmds = ctb->cmds;
304 unsigned int i;
305
306 GEM_BUG_ON(desc->size % 4);
307 GEM_BUG_ON(desc->head % 4);
308 GEM_BUG_ON(desc->tail % 4);
309 GEM_BUG_ON(tail >= size);
310
311 /*
312 * tail == head condition indicates empty. GuC FW does not support
313 * using up the entire buffer to get tail == head meaning full.
314 */
315 if (tail < head)
316 used = (size - head) + tail;
317 else
318 used = tail - head;
319
320 /* make sure there is a space including extra dw for the fence */
321 if (unlikely(used + len + 1 >= size))
322 return -ENOSPC;
323
324 /*
325 * Write the message. The format is the following:
326 * DW0: header (including action code)
327 * DW1: fence
328 * DW2+: action data
329 */
330 header = (len << GUC_CT_MSG_LEN_SHIFT) |
331 (GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
332 (want_response ? GUC_CT_MSG_SEND_STATUS : 0) |
333 (action[0] << GUC_CT_MSG_ACTION_SHIFT);
334
335 CT_DEBUG_DRIVER("CT: writing %*ph %*ph %*ph\n",
336 4, &header, 4, &fence,
337 4 * (len - 1), &action[1]);
338
339 cmds[tail] = header;
340 tail = (tail + 1) % size;
341
342 cmds[tail] = fence;
343 tail = (tail + 1) % size;
344
345 for (i = 1; i < len; i++) {
346 cmds[tail] = action[i];
347 tail = (tail + 1) % size;
348 }
349
350 /* now update desc tail (back in bytes) */
351 desc->tail = tail * 4;
352 GEM_BUG_ON(desc->tail > desc->size);
353
354 return 0;
355 }
356
357 /**
358 * wait_for_ctb_desc_update - Wait for the CT buffer descriptor update.
359 * @desc: buffer descriptor
360 * @fence: response fence
361 * @status: placeholder for status
362 *
363 * Guc will update CT buffer descriptor with new fence and status
364 * after processing the command identified by the fence. Wait for
365 * specified fence and then read from the descriptor status of the
366 * command.
367 *
368 * Return:
369 * * 0 response received (status is valid)
370 * * -ETIMEDOUT no response within hardcoded timeout
371 * * -EPROTO no response, CT buffer is in error
372 */
wait_for_ctb_desc_update(struct guc_ct_buffer_desc * desc,u32 fence,u32 * status)373 static int wait_for_ctb_desc_update(struct guc_ct_buffer_desc *desc,
374 u32 fence,
375 u32 *status)
376 {
377 int err;
378
379 /*
380 * Fast commands should complete in less than 10us, so sample quickly
381 * up to that length of time, then switch to a slower sleep-wait loop.
382 * No GuC command should ever take longer than 10ms.
383 */
384 #define done (READ_ONCE(desc->fence) == fence)
385 err = wait_for_us(done, 10);
386 if (err)
387 err = wait_for(done, 10);
388 #undef done
389
390 if (unlikely(err)) {
391 DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
392 fence, desc->fence);
393
394 if (WARN_ON(desc->is_in_error)) {
395 /* Something went wrong with the messaging, try to reset
396 * the buffer and hope for the best
397 */
398 guc_ct_buffer_desc_reset(desc);
399 err = -EPROTO;
400 }
401 }
402
403 *status = desc->status;
404 return err;
405 }
406
407 /**
408 * wait_for_ct_request_update - Wait for CT request state update.
409 * @req: pointer to pending request
410 * @status: placeholder for status
411 *
412 * For each sent request, Guc shall send bac CT response message.
413 * Our message handler will update status of tracked request once
414 * response message with given fence is received. Wait here and
415 * check for valid response status value.
416 *
417 * Return:
418 * * 0 response received (status is valid)
419 * * -ETIMEDOUT no response within hardcoded timeout
420 */
wait_for_ct_request_update(struct ct_request * req,u32 * status)421 static int wait_for_ct_request_update(struct ct_request *req, u32 *status)
422 {
423 int err;
424
425 /*
426 * Fast commands should complete in less than 10us, so sample quickly
427 * up to that length of time, then switch to a slower sleep-wait loop.
428 * No GuC command should ever take longer than 10ms.
429 */
430 #define done INTEL_GUC_MSG_IS_RESPONSE(READ_ONCE(req->status))
431 err = wait_for_us(done, 10);
432 if (err)
433 err = wait_for(done, 10);
434 #undef done
435
436 if (unlikely(err))
437 DRM_ERROR("CT: fence %u err %d\n", req->fence, err);
438
439 *status = req->status;
440 return err;
441 }
442
ctch_send(struct intel_guc_ct * ct,struct intel_guc_ct_channel * ctch,const u32 * action,u32 len,u32 * response_buf,u32 response_buf_size,u32 * status)443 static int ctch_send(struct intel_guc_ct *ct,
444 struct intel_guc_ct_channel *ctch,
445 const u32 *action,
446 u32 len,
447 u32 *response_buf,
448 u32 response_buf_size,
449 u32 *status)
450 {
451 struct intel_guc_ct_buffer *ctb = &ctch->ctbs[CTB_SEND];
452 struct guc_ct_buffer_desc *desc = ctb->desc;
453 struct ct_request request;
454 unsigned long flags;
455 u32 fence;
456 int err;
457
458 GEM_BUG_ON(!ctch->enabled);
459 GEM_BUG_ON(!len);
460 GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK);
461 GEM_BUG_ON(!response_buf && response_buf_size);
462
463 fence = ctch_get_next_fence(ctch);
464 request.fence = fence;
465 request.status = 0;
466 request.response_len = response_buf_size;
467 request.response_buf = response_buf;
468
469 spin_lock_irqsave(&ct->lock, flags);
470 list_add_tail(&request.link, &ct->pending_requests);
471 spin_unlock_irqrestore(&ct->lock, flags);
472
473 err = ctb_write(ctb, action, len, fence, !!response_buf);
474 if (unlikely(err))
475 goto unlink;
476
477 intel_guc_notify(ct_to_guc(ct));
478
479 if (response_buf)
480 err = wait_for_ct_request_update(&request, status);
481 else
482 err = wait_for_ctb_desc_update(desc, fence, status);
483 if (unlikely(err))
484 goto unlink;
485
486 if (!INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(*status)) {
487 err = -EIO;
488 goto unlink;
489 }
490
491 if (response_buf) {
492 /* There shall be no data in the status */
493 WARN_ON(INTEL_GUC_MSG_TO_DATA(request.status));
494 /* Return actual response len */
495 err = request.response_len;
496 } else {
497 /* There shall be no response payload */
498 WARN_ON(request.response_len);
499 /* Return data decoded from the status dword */
500 err = INTEL_GUC_MSG_TO_DATA(*status);
501 }
502
503 unlink:
504 spin_lock_irqsave(&ct->lock, flags);
505 list_del(&request.link);
506 spin_unlock_irqrestore(&ct->lock, flags);
507
508 return err;
509 }
510
511 /*
512 * Command Transport (CT) buffer based GuC send function.
513 */
intel_guc_send_ct(struct intel_guc * guc,const u32 * action,u32 len,u32 * response_buf,u32 response_buf_size)514 int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len,
515 u32 *response_buf, u32 response_buf_size)
516 {
517 struct intel_guc_ct *ct = &guc->ct;
518 struct intel_guc_ct_channel *ctch = &ct->host_channel;
519 u32 status = ~0; /* undefined */
520 int ret;
521
522 mutex_lock(&guc->send_mutex);
523
524 ret = ctch_send(ct, ctch, action, len, response_buf, response_buf_size,
525 &status);
526 if (unlikely(ret < 0)) {
527 DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
528 action[0], ret, status);
529 } else if (unlikely(ret)) {
530 CT_DEBUG_DRIVER("CT: send action %#x returned %d (%#x)\n",
531 action[0], ret, ret);
532 }
533
534 mutex_unlock(&guc->send_mutex);
535 return ret;
536 }
537
ct_header_get_len(u32 header)538 static inline unsigned int ct_header_get_len(u32 header)
539 {
540 return (header >> GUC_CT_MSG_LEN_SHIFT) & GUC_CT_MSG_LEN_MASK;
541 }
542
ct_header_get_action(u32 header)543 static inline unsigned int ct_header_get_action(u32 header)
544 {
545 return (header >> GUC_CT_MSG_ACTION_SHIFT) & GUC_CT_MSG_ACTION_MASK;
546 }
547
ct_header_is_response(u32 header)548 static inline bool ct_header_is_response(u32 header)
549 {
550 return !!(header & GUC_CT_MSG_IS_RESPONSE);
551 }
552
ctb_read(struct intel_guc_ct_buffer * ctb,u32 * data)553 static int ctb_read(struct intel_guc_ct_buffer *ctb, u32 *data)
554 {
555 struct guc_ct_buffer_desc *desc = ctb->desc;
556 u32 head = desc->head / 4; /* in dwords */
557 u32 tail = desc->tail / 4; /* in dwords */
558 u32 size = desc->size / 4; /* in dwords */
559 u32 *cmds = ctb->cmds;
560 s32 available; /* in dwords */
561 unsigned int len;
562 unsigned int i;
563
564 GEM_BUG_ON(desc->size % 4);
565 GEM_BUG_ON(desc->head % 4);
566 GEM_BUG_ON(desc->tail % 4);
567 GEM_BUG_ON(tail >= size);
568 GEM_BUG_ON(head >= size);
569
570 /* tail == head condition indicates empty */
571 available = tail - head;
572 if (unlikely(available == 0))
573 return -ENODATA;
574
575 /* beware of buffer wrap case */
576 if (unlikely(available < 0))
577 available += size;
578 CT_DEBUG_DRIVER("CT: available %d (%u:%u)\n", available, head, tail);
579 GEM_BUG_ON(available < 0);
580
581 data[0] = cmds[head];
582 head = (head + 1) % size;
583
584 /* message len with header */
585 len = ct_header_get_len(data[0]) + 1;
586 if (unlikely(len > (u32)available)) {
587 DRM_ERROR("CT: incomplete message %*ph %*ph %*ph\n",
588 4, data,
589 4 * (head + available - 1 > size ?
590 size - head : available - 1), &cmds[head],
591 4 * (head + available - 1 > size ?
592 available - 1 - size + head : 0), &cmds[0]);
593 return -EPROTO;
594 }
595
596 for (i = 1; i < len; i++) {
597 data[i] = cmds[head];
598 head = (head + 1) % size;
599 }
600 CT_DEBUG_DRIVER("CT: received %*ph\n", 4 * len, data);
601
602 desc->head = head * 4;
603 return 0;
604 }
605
606 /**
607 * DOC: CTB GuC to Host response
608 *
609 * Format of the CTB GuC to Host response message is as follows::
610 *
611 * +------------+---------+---------+---------+---------+---------+
612 * | msg[0] | [1] | [2] | [3] | ... | [n-1] |
613 * +------------+---------+---------+---------+---------+---------+
614 * | MESSAGE | MESSAGE PAYLOAD |
615 * + HEADER +---------+---------+---------+---------+---------+
616 * | | 0 | 1 | 2 | ... | n |
617 * +============+=========+=========+=========+=========+=========+
618 * | len >= 2 | FENCE | STATUS | response specific data |
619 * +------+-----+---------+---------+---------+---------+---------+
620 *
621 * ^-----------------------len-----------------------^
622 */
623
ct_handle_response(struct intel_guc_ct * ct,const u32 * msg)624 static int ct_handle_response(struct intel_guc_ct *ct, const u32 *msg)
625 {
626 u32 header = msg[0];
627 u32 len = ct_header_get_len(header);
628 u32 msglen = len + 1; /* total message length including header */
629 u32 fence;
630 u32 status;
631 u32 datalen;
632 struct ct_request *req;
633 bool found = false;
634
635 GEM_BUG_ON(!ct_header_is_response(header));
636 GEM_BUG_ON(!in_irq());
637
638 /* Response payload shall at least include fence and status */
639 if (unlikely(len < 2)) {
640 DRM_ERROR("CT: corrupted response %*ph\n", 4 * msglen, msg);
641 return -EPROTO;
642 }
643
644 fence = msg[1];
645 status = msg[2];
646 datalen = len - 2;
647
648 /* Format of the status follows RESPONSE message */
649 if (unlikely(!INTEL_GUC_MSG_IS_RESPONSE(status))) {
650 DRM_ERROR("CT: corrupted response %*ph\n", 4 * msglen, msg);
651 return -EPROTO;
652 }
653
654 CT_DEBUG_DRIVER("CT: response fence %u status %#x\n", fence, status);
655
656 spin_lock(&ct->lock);
657 list_for_each_entry(req, &ct->pending_requests, link) {
658 if (unlikely(fence != req->fence)) {
659 CT_DEBUG_DRIVER("CT: request %u awaits response\n",
660 req->fence);
661 continue;
662 }
663 if (unlikely(datalen > req->response_len)) {
664 DRM_ERROR("CT: response %u too long %*ph\n",
665 req->fence, 4 * msglen, msg);
666 datalen = 0;
667 }
668 if (datalen)
669 memcpy(req->response_buf, msg + 3, 4 * datalen);
670 req->response_len = datalen;
671 WRITE_ONCE(req->status, status);
672 found = true;
673 break;
674 }
675 spin_unlock(&ct->lock);
676
677 if (!found)
678 DRM_ERROR("CT: unsolicited response %*ph\n", 4 * msglen, msg);
679 return 0;
680 }
681
ct_process_request(struct intel_guc_ct * ct,u32 action,u32 len,const u32 * payload)682 static void ct_process_request(struct intel_guc_ct *ct,
683 u32 action, u32 len, const u32 *payload)
684 {
685 struct intel_guc *guc = ct_to_guc(ct);
686 int ret;
687
688 CT_DEBUG_DRIVER("CT: request %x %*ph\n", action, 4 * len, payload);
689
690 switch (action) {
691 case INTEL_GUC_ACTION_DEFAULT:
692 ret = intel_guc_to_host_process_recv_msg(guc, payload, len);
693 if (unlikely(ret))
694 goto fail_unexpected;
695 break;
696
697 default:
698 fail_unexpected:
699 DRM_ERROR("CT: unexpected request %x %*ph\n",
700 action, 4 * len, payload);
701 break;
702 }
703 }
704
ct_process_incoming_requests(struct intel_guc_ct * ct)705 static bool ct_process_incoming_requests(struct intel_guc_ct *ct)
706 {
707 unsigned long flags;
708 struct ct_incoming_request *request;
709 u32 header;
710 u32 *payload;
711 bool done;
712
713 spin_lock_irqsave(&ct->lock, flags);
714 request = list_first_entry_or_null(&ct->incoming_requests,
715 struct ct_incoming_request, link);
716 if (request)
717 list_del(&request->link);
718 done = !!list_empty(&ct->incoming_requests);
719 spin_unlock_irqrestore(&ct->lock, flags);
720
721 if (!request)
722 return true;
723
724 header = request->msg[0];
725 payload = &request->msg[1];
726 ct_process_request(ct,
727 ct_header_get_action(header),
728 ct_header_get_len(header),
729 payload);
730
731 kfree(request);
732 return done;
733 }
734
ct_incoming_request_worker_func(struct work_struct * w)735 static void ct_incoming_request_worker_func(struct work_struct *w)
736 {
737 struct intel_guc_ct *ct = container_of(w, struct intel_guc_ct, worker);
738 bool done;
739
740 done = ct_process_incoming_requests(ct);
741 if (!done)
742 queue_work(system_unbound_wq, &ct->worker);
743 }
744
745 /**
746 * DOC: CTB GuC to Host request
747 *
748 * Format of the CTB GuC to Host request message is as follows::
749 *
750 * +------------+---------+---------+---------+---------+---------+
751 * | msg[0] | [1] | [2] | [3] | ... | [n-1] |
752 * +------------+---------+---------+---------+---------+---------+
753 * | MESSAGE | MESSAGE PAYLOAD |
754 * + HEADER +---------+---------+---------+---------+---------+
755 * | | 0 | 1 | 2 | ... | n |
756 * +============+=========+=========+=========+=========+=========+
757 * | len | request specific data |
758 * +------+-----+---------+---------+---------+---------+---------+
759 *
760 * ^-----------------------len-----------------------^
761 */
762
ct_handle_request(struct intel_guc_ct * ct,const u32 * msg)763 static int ct_handle_request(struct intel_guc_ct *ct, const u32 *msg)
764 {
765 u32 header = msg[0];
766 u32 len = ct_header_get_len(header);
767 u32 msglen = len + 1; /* total message length including header */
768 struct ct_incoming_request *request;
769 unsigned long flags;
770
771 GEM_BUG_ON(ct_header_is_response(header));
772
773 request = kmalloc(sizeof(*request) + 4 * msglen, GFP_ATOMIC);
774 if (unlikely(!request)) {
775 DRM_ERROR("CT: dropping request %*ph\n", 4 * msglen, msg);
776 return 0; /* XXX: -ENOMEM ? */
777 }
778 memcpy(request->msg, msg, 4 * msglen);
779
780 spin_lock_irqsave(&ct->lock, flags);
781 list_add_tail(&request->link, &ct->incoming_requests);
782 spin_unlock_irqrestore(&ct->lock, flags);
783
784 queue_work(system_unbound_wq, &ct->worker);
785 return 0;
786 }
787
ct_process_host_channel(struct intel_guc_ct * ct)788 static void ct_process_host_channel(struct intel_guc_ct *ct)
789 {
790 struct intel_guc_ct_channel *ctch = &ct->host_channel;
791 struct intel_guc_ct_buffer *ctb = &ctch->ctbs[CTB_RECV];
792 u32 msg[GUC_CT_MSG_LEN_MASK + 1]; /* one extra dw for the header */
793 int err = 0;
794
795 if (!ctch->enabled)
796 return;
797
798 do {
799 err = ctb_read(ctb, msg);
800 if (err)
801 break;
802
803 if (ct_header_is_response(msg[0]))
804 err = ct_handle_response(ct, msg);
805 else
806 err = ct_handle_request(ct, msg);
807 } while (!err);
808
809 if (GEM_WARN_ON(err == -EPROTO)) {
810 DRM_ERROR("CT: corrupted message detected!\n");
811 ctb->desc->is_in_error = 1;
812 }
813 }
814
815 /*
816 * When we're communicating with the GuC over CT, GuC uses events
817 * to notify us about new messages being posted on the RECV buffer.
818 */
intel_guc_to_host_event_handler_ct(struct intel_guc * guc)819 void intel_guc_to_host_event_handler_ct(struct intel_guc *guc)
820 {
821 struct intel_guc_ct *ct = &guc->ct;
822
823 ct_process_host_channel(ct);
824 }
825
826 /**
827 * intel_guc_ct_init - Init CT communication
828 * @ct: pointer to CT struct
829 *
830 * Allocate memory required for communication via
831 * the CT channel.
832 *
833 * Return: 0 on success, a negative errno code on failure.
834 */
intel_guc_ct_init(struct intel_guc_ct * ct)835 int intel_guc_ct_init(struct intel_guc_ct *ct)
836 {
837 struct intel_guc *guc = ct_to_guc(ct);
838 struct intel_guc_ct_channel *ctch = &ct->host_channel;
839 int err;
840
841 err = ctch_init(guc, ctch);
842 if (unlikely(err)) {
843 DRM_ERROR("CT: can't open channel %d; err=%d\n",
844 ctch->owner, err);
845 return err;
846 }
847
848 GEM_BUG_ON(!ctch->vma);
849 return 0;
850 }
851
852 /**
853 * intel_guc_ct_fini - Fini CT communication
854 * @ct: pointer to CT struct
855 *
856 * Deallocate memory required for communication via
857 * the CT channel.
858 */
intel_guc_ct_fini(struct intel_guc_ct * ct)859 void intel_guc_ct_fini(struct intel_guc_ct *ct)
860 {
861 struct intel_guc *guc = ct_to_guc(ct);
862 struct intel_guc_ct_channel *ctch = &ct->host_channel;
863
864 ctch_fini(guc, ctch);
865 }
866
867 /**
868 * intel_guc_ct_enable - Enable buffer based command transport.
869 * @ct: pointer to CT struct
870 *
871 * Return: 0 on success, a negative errno code on failure.
872 */
intel_guc_ct_enable(struct intel_guc_ct * ct)873 int intel_guc_ct_enable(struct intel_guc_ct *ct)
874 {
875 struct intel_guc *guc = ct_to_guc(ct);
876 struct intel_guc_ct_channel *ctch = &ct->host_channel;
877
878 if (ctch->enabled)
879 return 0;
880
881 return ctch_enable(guc, ctch);
882 }
883
884 /**
885 * intel_guc_ct_disable - Disable buffer based command transport.
886 * @ct: pointer to CT struct
887 */
intel_guc_ct_disable(struct intel_guc_ct * ct)888 void intel_guc_ct_disable(struct intel_guc_ct *ct)
889 {
890 struct intel_guc *guc = ct_to_guc(ct);
891 struct intel_guc_ct_channel *ctch = &ct->host_channel;
892
893 if (!ctch->enabled)
894 return;
895
896 ctch_disable(guc, ctch);
897 }
898
