1 /*
2  * Copyright © 2014 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  */
24 #include <linux/firmware.h>
25 #include <linux/circ_buf.h>
26 #include "i915_drv.h"
27 #include "intel_guc.h"
28 
29 /**
30  * DOC: GuC-based command submission
31  *
32  * i915_guc_client:
33  * We use the term client to avoid confusion with contexts. A i915_guc_client is
34  * equivalent to GuC object guc_context_desc. This context descriptor is
35  * allocated from a pool of 1024 entries. Kernel driver will allocate doorbell
36  * and workqueue for it. Also the process descriptor (guc_process_desc), which
37  * is mapped to client space. So the client can write Work Item then ring the
38  * doorbell.
39  *
40  * To simplify the implementation, we allocate one gem object that contains all
41  * pages for doorbell, process descriptor and workqueue.
42  *
43  * The Scratch registers:
44  * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes
45  * a value to the action register (SOFT_SCRATCH_0) along with any data. It then
46  * triggers an interrupt on the GuC via another register write (0xC4C8).
47  * Firmware writes a success/fail code back to the action register after
48  * processes the request. The kernel driver polls waiting for this update and
49  * then proceeds.
50  * See host2guc_action()
51  *
52  * Doorbells:
53  * Doorbells are interrupts to uKernel. A doorbell is a single cache line (QW)
54  * mapped into process space.
55  *
56  * Work Items:
57  * There are several types of work items that the host may place into a
58  * workqueue, each with its own requirements and limitations. Currently only
59  * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which
60  * represents in-order queue. The kernel driver packs ring tail pointer and an
61  * ELSP context descriptor dword into Work Item.
62  * See guc_wq_item_append()
63  *
64  */
65 
66 /*
67  * Read GuC command/status register (SOFT_SCRATCH_0)
68  * Return true if it contains a response rather than a command
69  */
70 static inline bool host2guc_action_response(struct drm_i915_private *dev_priv,
71 					    u32 *status)
72 {
73 	u32 val = I915_READ(SOFT_SCRATCH(0));
74 	*status = val;
75 	return GUC2HOST_IS_RESPONSE(val);
76 }
77 
78 static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len)
79 {
80 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
81 	u32 status;
82 	int i;
83 	int ret;
84 
85 	if (WARN_ON(len < 1 || len > 15))
86 		return -EINVAL;
87 
88 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
89 
90 	dev_priv->guc.action_count += 1;
91 	dev_priv->guc.action_cmd = data[0];
92 
93 	for (i = 0; i < len; i++)
94 		I915_WRITE(SOFT_SCRATCH(i), data[i]);
95 
96 	POSTING_READ(SOFT_SCRATCH(i - 1));
97 
98 	I915_WRITE(HOST2GUC_INTERRUPT, HOST2GUC_TRIGGER);
99 
100 	/*
101 	 * Fast commands should complete in less than 10us, so sample quickly
102 	 * up to that length of time, then switch to a slower sleep-wait loop.
103 	 * No HOST2GUC command should ever take longer than 10ms.
104 	 */
105 	ret = wait_for_us(host2guc_action_response(dev_priv, &status), 10);
106 	if (ret)
107 		ret = wait_for(host2guc_action_response(dev_priv, &status), 10);
108 	if (status != GUC2HOST_STATUS_SUCCESS) {
109 		/*
110 		 * Either the GuC explicitly returned an error (which
111 		 * we convert to -EIO here) or no response at all was
112 		 * received within the timeout limit (-ETIMEDOUT)
113 		 */
114 		if (ret != -ETIMEDOUT)
115 			ret = -EIO;
116 
117 		DRM_WARN("Action 0x%X failed; ret=%d status=0x%08X response=0x%08X\n",
118 			 data[0], ret, status, I915_READ(SOFT_SCRATCH(15)));
119 
120 		dev_priv->guc.action_fail += 1;
121 		dev_priv->guc.action_err = ret;
122 	}
123 	dev_priv->guc.action_status = status;
124 
125 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
126 
127 	return ret;
128 }
129 
130 /*
131  * Tell the GuC to allocate or deallocate a specific doorbell
132  */
133 
134 static int host2guc_allocate_doorbell(struct intel_guc *guc,
135 				      struct i915_guc_client *client)
136 {
137 	u32 data[2];
138 
139 	data[0] = HOST2GUC_ACTION_ALLOCATE_DOORBELL;
140 	data[1] = client->ctx_index;
141 
142 	return host2guc_action(guc, data, 2);
143 }
144 
145 static int host2guc_release_doorbell(struct intel_guc *guc,
146 				     struct i915_guc_client *client)
147 {
148 	u32 data[2];
149 
150 	data[0] = HOST2GUC_ACTION_DEALLOCATE_DOORBELL;
151 	data[1] = client->ctx_index;
152 
153 	return host2guc_action(guc, data, 2);
154 }
155 
156 static int host2guc_sample_forcewake(struct intel_guc *guc,
157 				     struct i915_guc_client *client)
158 {
159 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
160 	u32 data[2];
161 
162 	data[0] = HOST2GUC_ACTION_SAMPLE_FORCEWAKE;
163 	/* WaRsDisableCoarsePowerGating:skl,bxt */
164 	if (!intel_enable_rc6() || NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
165 		data[1] = 0;
166 	else
167 		/* bit 0 and 1 are for Render and Media domain separately */
168 		data[1] = GUC_FORCEWAKE_RENDER | GUC_FORCEWAKE_MEDIA;
169 
170 	return host2guc_action(guc, data, ARRAY_SIZE(data));
171 }
172 
173 /*
174  * Initialise, update, or clear doorbell data shared with the GuC
175  *
176  * These functions modify shared data and so need access to the mapped
177  * client object which contains the page being used for the doorbell
178  */
179 
180 static int guc_update_doorbell_id(struct intel_guc *guc,
181 				  struct i915_guc_client *client,
182 				  u16 new_id)
183 {
184 	struct sg_table *sg = guc->ctx_pool_vma->pages;
185 	void *doorbell_bitmap = guc->doorbell_bitmap;
186 	struct guc_doorbell_info *doorbell;
187 	struct guc_context_desc desc;
188 	size_t len;
189 
190 	doorbell = client->client_base + client->doorbell_offset;
191 
192 	if (client->doorbell_id != GUC_INVALID_DOORBELL_ID &&
193 	    test_bit(client->doorbell_id, doorbell_bitmap)) {
194 		/* Deactivate the old doorbell */
195 		doorbell->db_status = GUC_DOORBELL_DISABLED;
196 		(void)host2guc_release_doorbell(guc, client);
197 		__clear_bit(client->doorbell_id, doorbell_bitmap);
198 	}
199 
200 	/* Update the GuC's idea of the doorbell ID */
201 	len = sg_pcopy_to_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
202 			     sizeof(desc) * client->ctx_index);
203 	if (len != sizeof(desc))
204 		return -EFAULT;
205 	desc.db_id = new_id;
206 	len = sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
207 			     sizeof(desc) * client->ctx_index);
208 	if (len != sizeof(desc))
209 		return -EFAULT;
210 
211 	client->doorbell_id = new_id;
212 	if (new_id == GUC_INVALID_DOORBELL_ID)
213 		return 0;
214 
215 	/* Activate the new doorbell */
216 	__set_bit(new_id, doorbell_bitmap);
217 	doorbell->cookie = 0;
218 	doorbell->db_status = GUC_DOORBELL_ENABLED;
219 	return host2guc_allocate_doorbell(guc, client);
220 }
221 
222 static int guc_init_doorbell(struct intel_guc *guc,
223 			      struct i915_guc_client *client,
224 			      uint16_t db_id)
225 {
226 	return guc_update_doorbell_id(guc, client, db_id);
227 }
228 
229 static void guc_disable_doorbell(struct intel_guc *guc,
230 				 struct i915_guc_client *client)
231 {
232 	(void)guc_update_doorbell_id(guc, client, GUC_INVALID_DOORBELL_ID);
233 
234 	/* XXX: wait for any interrupts */
235 	/* XXX: wait for workqueue to drain */
236 }
237 
238 static uint16_t
239 select_doorbell_register(struct intel_guc *guc, uint32_t priority)
240 {
241 	/*
242 	 * The bitmap tracks which doorbell registers are currently in use.
243 	 * It is split into two halves; the first half is used for normal
244 	 * priority contexts, the second half for high-priority ones.
245 	 * Note that logically higher priorities are numerically less than
246 	 * normal ones, so the test below means "is it high-priority?"
247 	 */
248 	const bool hi_pri = (priority <= GUC_CTX_PRIORITY_HIGH);
249 	const uint16_t half = GUC_MAX_DOORBELLS / 2;
250 	const uint16_t start = hi_pri ? half : 0;
251 	const uint16_t end = start + half;
252 	uint16_t id;
253 
254 	id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
255 	if (id == end)
256 		id = GUC_INVALID_DOORBELL_ID;
257 
258 	DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
259 			hi_pri ? "high" : "normal", id);
260 
261 	return id;
262 }
263 
264 /*
265  * Select, assign and relase doorbell cachelines
266  *
267  * These functions track which doorbell cachelines are in use.
268  * The data they manipulate is protected by the host2guc lock.
269  */
270 
271 static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
272 {
273 	const uint32_t cacheline_size = cache_line_size();
274 	uint32_t offset;
275 
276 	/* Doorbell uses a single cache line within a page */
277 	offset = offset_in_page(guc->db_cacheline);
278 
279 	/* Moving to next cache line to reduce contention */
280 	guc->db_cacheline += cacheline_size;
281 
282 	DRM_DEBUG_DRIVER("selected doorbell cacheline 0x%x, next 0x%x, linesize %u\n",
283 			offset, guc->db_cacheline, cacheline_size);
284 
285 	return offset;
286 }
287 
288 /*
289  * Initialise the process descriptor shared with the GuC firmware.
290  */
291 static void guc_proc_desc_init(struct intel_guc *guc,
292 			       struct i915_guc_client *client)
293 {
294 	struct guc_process_desc *desc;
295 
296 	desc = client->client_base + client->proc_desc_offset;
297 
298 	memset(desc, 0, sizeof(*desc));
299 
300 	/*
301 	 * XXX: pDoorbell and WQVBaseAddress are pointers in process address
302 	 * space for ring3 clients (set them as in mmap_ioctl) or kernel
303 	 * space for kernel clients (map on demand instead? May make debug
304 	 * easier to have it mapped).
305 	 */
306 	desc->wq_base_addr = 0;
307 	desc->db_base_addr = 0;
308 
309 	desc->context_id = client->ctx_index;
310 	desc->wq_size_bytes = client->wq_size;
311 	desc->wq_status = WQ_STATUS_ACTIVE;
312 	desc->priority = client->priority;
313 }
314 
315 /*
316  * Initialise/clear the context descriptor shared with the GuC firmware.
317  *
318  * This descriptor tells the GuC where (in GGTT space) to find the important
319  * data structures relating to this client (doorbell, process descriptor,
320  * write queue, etc).
321  */
322 
323 static void guc_ctx_desc_init(struct intel_guc *guc,
324 			      struct i915_guc_client *client)
325 {
326 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
327 	struct intel_engine_cs *engine;
328 	struct i915_gem_context *ctx = client->owner;
329 	struct guc_context_desc desc;
330 	struct sg_table *sg;
331 	unsigned int tmp;
332 	u32 gfx_addr;
333 
334 	memset(&desc, 0, sizeof(desc));
335 
336 	desc.attribute = GUC_CTX_DESC_ATTR_ACTIVE | GUC_CTX_DESC_ATTR_KERNEL;
337 	desc.context_id = client->ctx_index;
338 	desc.priority = client->priority;
339 	desc.db_id = client->doorbell_id;
340 
341 	for_each_engine_masked(engine, dev_priv, client->engines, tmp) {
342 		struct intel_context *ce = &ctx->engine[engine->id];
343 		uint32_t guc_engine_id = engine->guc_id;
344 		struct guc_execlist_context *lrc = &desc.lrc[guc_engine_id];
345 
346 		/* TODO: We have a design issue to be solved here. Only when we
347 		 * receive the first batch, we know which engine is used by the
348 		 * user. But here GuC expects the lrc and ring to be pinned. It
349 		 * is not an issue for default context, which is the only one
350 		 * for now who owns a GuC client. But for future owner of GuC
351 		 * client, need to make sure lrc is pinned prior to enter here.
352 		 */
353 		if (!ce->state)
354 			break;	/* XXX: continue? */
355 
356 		lrc->context_desc = lower_32_bits(ce->lrc_desc);
357 
358 		/* The state page is after PPHWSP */
359 		lrc->ring_lcra =
360 			i915_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE;
361 		lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) |
362 				(guc_engine_id << GUC_ELC_ENGINE_OFFSET);
363 
364 		lrc->ring_begin = i915_ggtt_offset(ce->ring->vma);
365 		lrc->ring_end = lrc->ring_begin + ce->ring->size - 1;
366 		lrc->ring_next_free_location = lrc->ring_begin;
367 		lrc->ring_current_tail_pointer_value = 0;
368 
369 		desc.engines_used |= (1 << guc_engine_id);
370 	}
371 
372 	DRM_DEBUG_DRIVER("Host engines 0x%x => GuC engines used 0x%x\n",
373 			client->engines, desc.engines_used);
374 	WARN_ON(desc.engines_used == 0);
375 
376 	/*
377 	 * The doorbell, process descriptor, and workqueue are all parts
378 	 * of the client object, which the GuC will reference via the GGTT
379 	 */
380 	gfx_addr = i915_ggtt_offset(client->vma);
381 	desc.db_trigger_phy = sg_dma_address(client->vma->pages->sgl) +
382 				client->doorbell_offset;
383 	desc.db_trigger_cpu = (uintptr_t)client->client_base +
384 				client->doorbell_offset;
385 	desc.db_trigger_uk = gfx_addr + client->doorbell_offset;
386 	desc.process_desc = gfx_addr + client->proc_desc_offset;
387 	desc.wq_addr = gfx_addr + client->wq_offset;
388 	desc.wq_size = client->wq_size;
389 
390 	/*
391 	 * XXX: Take LRCs from an existing context if this is not an
392 	 * IsKMDCreatedContext client
393 	 */
394 	desc.desc_private = (uintptr_t)client;
395 
396 	/* Pool context is pinned already */
397 	sg = guc->ctx_pool_vma->pages;
398 	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
399 			     sizeof(desc) * client->ctx_index);
400 }
401 
402 static void guc_ctx_desc_fini(struct intel_guc *guc,
403 			      struct i915_guc_client *client)
404 {
405 	struct guc_context_desc desc;
406 	struct sg_table *sg;
407 
408 	memset(&desc, 0, sizeof(desc));
409 
410 	sg = guc->ctx_pool_vma->pages;
411 	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
412 			     sizeof(desc) * client->ctx_index);
413 }
414 
415 /**
416  * i915_guc_wq_reserve() - reserve space in the GuC's workqueue
417  * @request:	request associated with the commands
418  *
419  * Return:	0 if space is available
420  *		-EAGAIN if space is not currently available
421  *
422  * This function must be called (and must return 0) before a request
423  * is submitted to the GuC via i915_guc_submit() below. Once a result
424  * of 0 has been returned, it must be balanced by a corresponding
425  * call to submit().
426  *
427  * Reservation allows the caller to determine in advance that space
428  * will be available for the next submission before committing resources
429  * to it, and helps avoid late failures with complicated recovery paths.
430  */
431 int i915_guc_wq_reserve(struct drm_i915_gem_request *request)
432 {
433 	const size_t wqi_size = sizeof(struct guc_wq_item);
434 	struct i915_guc_client *gc = request->i915->guc.execbuf_client;
435 	struct guc_process_desc *desc = gc->client_base + gc->proc_desc_offset;
436 	u32 freespace;
437 	int ret;
438 
439 	lockmgr(&gc->wq_lock, LK_EXCLUSIVE);
440 	freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size);
441 	freespace -= gc->wq_rsvd;
442 	if (likely(freespace >= wqi_size)) {
443 		gc->wq_rsvd += wqi_size;
444 		ret = 0;
445 	} else {
446 		gc->no_wq_space++;
447 		ret = -EAGAIN;
448 	}
449 	lockmgr(&gc->wq_lock, LK_RELEASE);
450 
451 	return ret;
452 }
453 
454 void i915_guc_wq_unreserve(struct drm_i915_gem_request *request)
455 {
456 	const size_t wqi_size = sizeof(struct guc_wq_item);
457 	struct i915_guc_client *gc = request->i915->guc.execbuf_client;
458 
459 	GEM_BUG_ON(READ_ONCE(gc->wq_rsvd) < wqi_size);
460 
461 	lockmgr(&gc->wq_lock, LK_EXCLUSIVE);
462 	gc->wq_rsvd -= wqi_size;
463 	lockmgr(&gc->wq_lock, LK_RELEASE);
464 }
465 
466 /* Construct a Work Item and append it to the GuC's Work Queue */
467 static void guc_wq_item_append(struct i915_guc_client *gc,
468 			       struct drm_i915_gem_request *rq)
469 {
470 	/* wqi_len is in DWords, and does not include the one-word header */
471 	const size_t wqi_size = sizeof(struct guc_wq_item);
472 	const u32 wqi_len = wqi_size/sizeof(u32) - 1;
473 	struct intel_engine_cs *engine = rq->engine;
474 	struct guc_process_desc *desc;
475 	struct guc_wq_item *wqi;
476 	void *base;
477 	u32 freespace, tail, wq_off, wq_page;
478 
479 	desc = gc->client_base + gc->proc_desc_offset;
480 
481 	/* Free space is guaranteed, see i915_guc_wq_reserve() above */
482 	freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size);
483 	GEM_BUG_ON(freespace < wqi_size);
484 
485 	/* The GuC firmware wants the tail index in QWords, not bytes */
486 	tail = rq->tail;
487 	GEM_BUG_ON(tail & 7);
488 	tail >>= 3;
489 	GEM_BUG_ON(tail > WQ_RING_TAIL_MAX);
490 
491 	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
492 	 * should not have the case where structure wqi is across page, neither
493 	 * wrapped to the beginning. This simplifies the implementation below.
494 	 *
495 	 * XXX: if not the case, we need save data to a temp wqi and copy it to
496 	 * workqueue buffer dw by dw.
497 	 */
498 	BUILD_BUG_ON(wqi_size != 16);
499 	GEM_BUG_ON(gc->wq_rsvd < wqi_size);
500 
501 	/* postincrement WQ tail for next time */
502 	wq_off = gc->wq_tail;
503 	GEM_BUG_ON(wq_off & (wqi_size - 1));
504 	gc->wq_tail += wqi_size;
505 	gc->wq_tail &= gc->wq_size - 1;
506 	gc->wq_rsvd -= wqi_size;
507 
508 	/* WQ starts from the page after doorbell / process_desc */
509 	wq_page = (wq_off + GUC_DB_SIZE) >> PAGE_SHIFT;
510 	wq_off &= PAGE_SIZE - 1;
511 	base = kmap_atomic(i915_gem_object_get_page(gc->vma->obj, wq_page));
512 	wqi = (struct guc_wq_item *)((char *)base + wq_off);
513 
514 	/* Now fill in the 4-word work queue item */
515 	wqi->header = WQ_TYPE_INORDER |
516 			(wqi_len << WQ_LEN_SHIFT) |
517 			(engine->guc_id << WQ_TARGET_SHIFT) |
518 			WQ_NO_WCFLUSH_WAIT;
519 
520 	/* The GuC wants only the low-order word of the context descriptor */
521 	wqi->context_desc = (u32)intel_lr_context_descriptor(rq->ctx, engine);
522 
523 	wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT;
524 	wqi->fence_id = rq->fence.seqno;
525 
526 	kunmap_atomic(base);
527 }
528 
529 static int guc_ring_doorbell(struct i915_guc_client *gc)
530 {
531 	struct guc_process_desc *desc;
532 	union guc_doorbell_qw db_cmp, db_exc, db_ret;
533 	union guc_doorbell_qw *db;
534 	int attempt = 2, ret = -EAGAIN;
535 
536 	desc = gc->client_base + gc->proc_desc_offset;
537 
538 	/* Update the tail so it is visible to GuC */
539 	desc->tail = gc->wq_tail;
540 
541 	/* current cookie */
542 	db_cmp.db_status = GUC_DOORBELL_ENABLED;
543 	db_cmp.cookie = gc->cookie;
544 
545 	/* cookie to be updated */
546 	db_exc.db_status = GUC_DOORBELL_ENABLED;
547 	db_exc.cookie = gc->cookie + 1;
548 	if (db_exc.cookie == 0)
549 		db_exc.cookie = 1;
550 
551 	/* pointer of current doorbell cacheline */
552 	db = gc->client_base + gc->doorbell_offset;
553 
554 	while (attempt--) {
555 		/* lets ring the doorbell */
556 		db_ret.value_qw = atomic64_cmpxchg((atomic64_t *)db,
557 			db_cmp.value_qw, db_exc.value_qw);
558 
559 		/* if the exchange was successfully executed */
560 		if (db_ret.value_qw == db_cmp.value_qw) {
561 			/* db was successfully rung */
562 			gc->cookie = db_exc.cookie;
563 			ret = 0;
564 			break;
565 		}
566 
567 		/* XXX: doorbell was lost and need to acquire it again */
568 		if (db_ret.db_status == GUC_DOORBELL_DISABLED)
569 			break;
570 
571 		DRM_WARN("Cookie mismatch. Expected %d, found %d\n",
572 			 db_cmp.cookie, db_ret.cookie);
573 
574 		/* update the cookie to newly read cookie from GuC */
575 		db_cmp.cookie = db_ret.cookie;
576 		db_exc.cookie = db_ret.cookie + 1;
577 		if (db_exc.cookie == 0)
578 			db_exc.cookie = 1;
579 	}
580 
581 	return ret;
582 }
583 
584 /**
585  * i915_guc_submit() - Submit commands through GuC
586  * @rq:		request associated with the commands
587  *
588  * Return:	0 on success, otherwise an errno.
589  * 		(Note: nonzero really shouldn't happen!)
590  *
591  * The caller must have already called i915_guc_wq_reserve() above with
592  * a result of 0 (success), guaranteeing that there is space in the work
593  * queue for the new request, so enqueuing the item cannot fail.
594  *
595  * Bad Things Will Happen if the caller violates this protocol e.g. calls
596  * submit() when _reserve() says there's no space, or calls _submit()
597  * a different number of times from (successful) calls to _reserve().
598  *
599  * The only error here arises if the doorbell hardware isn't functioning
600  * as expected, which really shouln't happen.
601  */
602 static void i915_guc_submit(struct drm_i915_gem_request *rq)
603 {
604 	unsigned int engine_id = rq->engine->id;
605 	struct intel_guc *guc = &rq->i915->guc;
606 	struct i915_guc_client *client = guc->execbuf_client;
607 	int b_ret;
608 
609 	lockmgr(&client->wq_lock, LK_EXCLUSIVE);
610 	guc_wq_item_append(client, rq);
611 	b_ret = guc_ring_doorbell(client);
612 
613 	client->submissions[engine_id] += 1;
614 	client->retcode = b_ret;
615 	if (b_ret)
616 		client->b_fail += 1;
617 
618 	guc->submissions[engine_id] += 1;
619 	guc->last_seqno[engine_id] = rq->fence.seqno;
620 	lockmgr(&client->wq_lock, LK_RELEASE);
621 }
622 
623 /*
624  * Everything below here is concerned with setup & teardown, and is
625  * therefore not part of the somewhat time-critical batch-submission
626  * path of i915_guc_submit() above.
627  */
628 
629 /**
630  * guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
631  * @guc:	the guc
632  * @size:	size of area to allocate (both virtual space and memory)
633  *
634  * This is a wrapper to create an object for use with the GuC. In order to
635  * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
636  * both some backing storage and a range inside the Global GTT. We must pin
637  * it in the GGTT somewhere other than than [0, GUC_WOPCM_TOP) because that
638  * range is reserved inside GuC.
639  *
640  * Return:	A i915_vma if successful, otherwise an ERR_PTR.
641  */
642 static struct i915_vma *guc_allocate_vma(struct intel_guc *guc, u32 size)
643 {
644 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
645 	struct drm_i915_gem_object *obj;
646 	struct i915_vma *vma;
647 	int ret;
648 
649 	obj = i915_gem_object_create(&dev_priv->drm, size);
650 	if (IS_ERR(obj))
651 		return ERR_CAST(obj);
652 
653 	vma = i915_vma_create(obj, &dev_priv->ggtt.base, NULL);
654 	if (IS_ERR(vma))
655 		goto err;
656 
657 	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
658 			   PIN_GLOBAL | PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
659 	if (ret) {
660 		vma = ERR_PTR(ret);
661 		goto err;
662 	}
663 
664 	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
665 	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
666 
667 	return vma;
668 
669 err:
670 	i915_gem_object_put(obj);
671 	return vma;
672 }
673 
674 static void
675 guc_client_free(struct drm_i915_private *dev_priv,
676 		struct i915_guc_client *client)
677 {
678 	struct intel_guc *guc = &dev_priv->guc;
679 
680 	if (!client)
681 		return;
682 
683 	/*
684 	 * XXX: wait for any outstanding submissions before freeing memory.
685 	 * Be sure to drop any locks
686 	 */
687 
688 	if (client->client_base) {
689 		/*
690 		 * If we got as far as setting up a doorbell, make sure we
691 		 * shut it down before unmapping & deallocating the memory.
692 		 */
693 		guc_disable_doorbell(guc, client);
694 
695 		kunmap(kmap_to_page(client->client_base));
696 	}
697 
698 	i915_vma_unpin_and_release(&client->vma);
699 
700 	if (client->ctx_index != GUC_INVALID_CTX_ID) {
701 		guc_ctx_desc_fini(guc, client);
702 		ida_simple_remove(&guc->ctx_ids, client->ctx_index);
703 	}
704 
705 	kfree(client);
706 }
707 
708 /* Check that a doorbell register is in the expected state */
709 static bool guc_doorbell_check(struct intel_guc *guc, uint16_t db_id)
710 {
711 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
712 	i915_reg_t drbreg = GEN8_DRBREGL(db_id);
713 	uint32_t value = I915_READ(drbreg);
714 	bool enabled = (value & GUC_DOORBELL_ENABLED) != 0;
715 	bool expected = test_bit(db_id, guc->doorbell_bitmap);
716 
717 	if (enabled == expected)
718 		return true;
719 
720 	DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) 0x%x, should be %s\n",
721 			 db_id, drbreg.reg, value,
722 			 expected ? "active" : "inactive");
723 
724 	return false;
725 }
726 
727 /*
728  * Borrow the first client to set up & tear down each unused doorbell
729  * in turn, to ensure that all doorbell h/w is (re)initialised.
730  */
731 static void guc_init_doorbell_hw(struct intel_guc *guc)
732 {
733 	struct i915_guc_client *client = guc->execbuf_client;
734 	uint16_t db_id;
735 	int i, err;
736 
737 	/* Save client's original doorbell selection */
738 	db_id = client->doorbell_id;
739 
740 	for (i = 0; i < GUC_MAX_DOORBELLS; ++i) {
741 		/* Skip if doorbell is OK */
742 		if (guc_doorbell_check(guc, i))
743 			continue;
744 
745 		err = guc_update_doorbell_id(guc, client, i);
746 		if (err)
747 			DRM_DEBUG_DRIVER("Doorbell %d update failed, err %d\n",
748 					i, err);
749 	}
750 
751 	/* Restore to original value */
752 	err = guc_update_doorbell_id(guc, client, db_id);
753 	if (err)
754 		DRM_WARN("Failed to restore doorbell to %d, err %d\n",
755 			 db_id, err);
756 
757 	/* Read back & verify all doorbell registers */
758 	for (i = 0; i < GUC_MAX_DOORBELLS; ++i)
759 		(void)guc_doorbell_check(guc, i);
760 }
761 
762 /**
763  * guc_client_alloc() - Allocate an i915_guc_client
764  * @dev_priv:	driver private data structure
765  * @engines:	The set of engines to enable for this client
766  * @priority:	four levels priority _CRITICAL, _HIGH, _NORMAL and _LOW
767  * 		The kernel client to replace ExecList submission is created with
768  * 		NORMAL priority. Priority of a client for scheduler can be HIGH,
769  * 		while a preemption context can use CRITICAL.
770  * @ctx:	the context that owns the client (we use the default render
771  * 		context)
772  *
773  * Return:	An i915_guc_client object if success, else NULL.
774  */
775 static struct i915_guc_client *
776 guc_client_alloc(struct drm_i915_private *dev_priv,
777 		 uint32_t engines,
778 		 uint32_t priority,
779 		 struct i915_gem_context *ctx)
780 {
781 	struct i915_guc_client *client;
782 	struct intel_guc *guc = &dev_priv->guc;
783 	struct i915_vma *vma;
784 	uint16_t db_id;
785 
786 	client = kzalloc(sizeof(*client), GFP_KERNEL);
787 	if (!client)
788 		return NULL;
789 
790 	client->owner = ctx;
791 	client->guc = guc;
792 	client->engines = engines;
793 	client->priority = priority;
794 	client->doorbell_id = GUC_INVALID_DOORBELL_ID;
795 
796 	client->ctx_index = (uint32_t)ida_simple_get(&guc->ctx_ids, 0,
797 			GUC_MAX_GPU_CONTEXTS, GFP_KERNEL);
798 	if (client->ctx_index >= GUC_MAX_GPU_CONTEXTS) {
799 		client->ctx_index = GUC_INVALID_CTX_ID;
800 		goto err;
801 	}
802 
803 	/* The first page is doorbell/proc_desc. Two followed pages are wq. */
804 	vma = guc_allocate_vma(guc, GUC_DB_SIZE + GUC_WQ_SIZE);
805 	if (IS_ERR(vma))
806 		goto err;
807 
808 	/* We'll keep just the first (doorbell/proc) page permanently kmap'd. */
809 	client->vma = vma;
810 	client->client_base = kmap(i915_vma_first_page(vma));
811 
812 	lockinit(&client->wq_lock, "i9gcwql", 0, 0);
813 	client->wq_offset = GUC_DB_SIZE;
814 	client->wq_size = GUC_WQ_SIZE;
815 
816 	db_id = select_doorbell_register(guc, client->priority);
817 	if (db_id == GUC_INVALID_DOORBELL_ID)
818 		/* XXX: evict a doorbell instead? */
819 		goto err;
820 
821 	client->doorbell_offset = select_doorbell_cacheline(guc);
822 
823 	/*
824 	 * Since the doorbell only requires a single cacheline, we can save
825 	 * space by putting the application process descriptor in the same
826 	 * page. Use the half of the page that doesn't include the doorbell.
827 	 */
828 	if (client->doorbell_offset >= (GUC_DB_SIZE / 2))
829 		client->proc_desc_offset = 0;
830 	else
831 		client->proc_desc_offset = (GUC_DB_SIZE / 2);
832 
833 	guc_proc_desc_init(guc, client);
834 	guc_ctx_desc_init(guc, client);
835 	if (guc_init_doorbell(guc, client, db_id))
836 		goto err;
837 
838 	DRM_DEBUG_DRIVER("new priority %u client %p for engine(s) 0x%x: ctx_index %u\n",
839 		priority, client, client->engines, client->ctx_index);
840 	DRM_DEBUG_DRIVER("doorbell id %u, cacheline offset 0x%x\n",
841 		client->doorbell_id, client->doorbell_offset);
842 
843 	return client;
844 
845 err:
846 	guc_client_free(dev_priv, client);
847 	return NULL;
848 }
849 
850 static void guc_log_create(struct intel_guc *guc)
851 {
852 	struct i915_vma *vma;
853 	unsigned long offset;
854 	uint32_t size, flags;
855 
856 	if (i915.guc_log_level < GUC_LOG_VERBOSITY_MIN)
857 		return;
858 
859 	if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
860 		i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;
861 
862 	/* The first page is to save log buffer state. Allocate one
863 	 * extra page for others in case for overlap */
864 	size = (1 + GUC_LOG_DPC_PAGES + 1 +
865 		GUC_LOG_ISR_PAGES + 1 +
866 		GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
867 
868 	vma = guc->log_vma;
869 	if (!vma) {
870 		vma = guc_allocate_vma(guc, size);
871 		if (IS_ERR(vma)) {
872 			/* logging will be off */
873 			i915.guc_log_level = -1;
874 			return;
875 		}
876 
877 		guc->log_vma = vma;
878 	}
879 
880 	/* each allocated unit is a page */
881 	flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
882 		(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
883 		(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
884 		(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
885 
886 	offset = i915_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
887 	guc->log_flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
888 }
889 
890 static void guc_policies_init(struct guc_policies *policies)
891 {
892 	struct guc_policy *policy;
893 	u32 p, i;
894 
895 	policies->dpc_promote_time = 500000;
896 	policies->max_num_work_items = POLICY_MAX_NUM_WI;
897 
898 	for (p = 0; p < GUC_CTX_PRIORITY_NUM; p++) {
899 		for (i = GUC_RENDER_ENGINE; i < GUC_MAX_ENGINES_NUM; i++) {
900 			policy = &policies->policy[p][i];
901 
902 			policy->execution_quantum = 1000000;
903 			policy->preemption_time = 500000;
904 			policy->fault_time = 250000;
905 			policy->policy_flags = 0;
906 		}
907 	}
908 
909 	policies->is_valid = 1;
910 }
911 
912 static void guc_addon_create(struct intel_guc *guc)
913 {
914 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
915 	struct i915_vma *vma;
916 	struct guc_ads *ads;
917 	struct guc_policies *policies;
918 	struct guc_mmio_reg_state *reg_state;
919 	struct intel_engine_cs *engine;
920 	enum intel_engine_id id;
921 	struct page *page;
922 	u32 size;
923 
924 	/* The ads obj includes the struct itself and buffers passed to GuC */
925 	size = sizeof(struct guc_ads) + sizeof(struct guc_policies) +
926 			sizeof(struct guc_mmio_reg_state) +
927 			GUC_S3_SAVE_SPACE_PAGES * PAGE_SIZE;
928 
929 	vma = guc->ads_vma;
930 	if (!vma) {
931 		vma = guc_allocate_vma(guc, PAGE_ALIGN(size));
932 		if (IS_ERR(vma))
933 			return;
934 
935 		guc->ads_vma = vma;
936 	}
937 
938 	page = i915_vma_first_page(vma);
939 	ads = kmap(page);
940 
941 	/*
942 	 * The GuC requires a "Golden Context" when it reinitialises
943 	 * engines after a reset. Here we use the Render ring default
944 	 * context, which must already exist and be pinned in the GGTT,
945 	 * so its address won't change after we've told the GuC where
946 	 * to find it.
947 	 */
948 	engine = dev_priv->engine[RCS];
949 	ads->golden_context_lrca = engine->status_page.ggtt_offset;
950 
951 	for_each_engine(engine, dev_priv, id)
952 		ads->eng_state_size[engine->guc_id] = intel_lr_context_size(engine);
953 
954 	/* GuC scheduling policies */
955 	policies = (void *)ads + sizeof(struct guc_ads);
956 	guc_policies_init(policies);
957 
958 	ads->scheduler_policies =
959 		i915_ggtt_offset(vma) + sizeof(struct guc_ads);
960 
961 	/* MMIO reg state */
962 	reg_state = (void *)policies + sizeof(struct guc_policies);
963 
964 	for_each_engine(engine, dev_priv, id) {
965 		reg_state->mmio_white_list[engine->guc_id].mmio_start =
966 			engine->mmio_base + GUC_MMIO_WHITE_LIST_START;
967 
968 		/* Nothing to be saved or restored for now. */
969 		reg_state->mmio_white_list[engine->guc_id].count = 0;
970 	}
971 
972 	ads->reg_state_addr = ads->scheduler_policies +
973 			sizeof(struct guc_policies);
974 
975 	ads->reg_state_buffer = ads->reg_state_addr +
976 			sizeof(struct guc_mmio_reg_state);
977 
978 	kunmap(page);
979 }
980 
981 /*
982  * Set up the memory resources to be shared with the GuC.  At this point,
983  * we require just one object that can be mapped through the GGTT.
984  */
985 int i915_guc_submission_init(struct drm_i915_private *dev_priv)
986 {
987 	const size_t ctxsize = sizeof(struct guc_context_desc);
988 	const size_t poolsize = GUC_MAX_GPU_CONTEXTS * ctxsize;
989 	const size_t gemsize = round_up(poolsize, PAGE_SIZE);
990 	struct intel_guc *guc = &dev_priv->guc;
991 	struct i915_vma *vma;
992 
993 	/* Wipe bitmap & delete client in case of reinitialisation */
994 	bitmap_clear(guc->doorbell_bitmap, 0, GUC_MAX_DOORBELLS);
995 	i915_guc_submission_disable(dev_priv);
996 
997 	if (!i915.enable_guc_submission)
998 		return 0; /* not enabled  */
999 
1000 	if (guc->ctx_pool_vma)
1001 		return 0; /* already allocated */
1002 
1003 	vma = guc_allocate_vma(guc, gemsize);
1004 	if (IS_ERR(vma))
1005 		return PTR_ERR(vma);
1006 
1007 	guc->ctx_pool_vma = vma;
1008 	ida_init(&guc->ctx_ids);
1009 	guc_log_create(guc);
1010 	guc_addon_create(guc);
1011 
1012 	return 0;
1013 }
1014 
1015 int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
1016 {
1017 	struct intel_guc *guc = &dev_priv->guc;
1018 	struct drm_i915_gem_request *request;
1019 	struct i915_guc_client *client;
1020 	struct intel_engine_cs *engine;
1021 	enum intel_engine_id id;
1022 
1023 	/* client for execbuf submission */
1024 	client = guc_client_alloc(dev_priv,
1025 				  INTEL_INFO(dev_priv)->ring_mask,
1026 				  GUC_CTX_PRIORITY_KMD_NORMAL,
1027 				  dev_priv->kernel_context);
1028 	if (!client) {
1029 		DRM_ERROR("Failed to create normal GuC client!\n");
1030 		return -ENOMEM;
1031 	}
1032 
1033 	guc->execbuf_client = client;
1034 	host2guc_sample_forcewake(guc, client);
1035 	guc_init_doorbell_hw(guc);
1036 
1037 	/* Take over from manual control of ELSP (execlists) */
1038 	for_each_engine(engine, dev_priv, id) {
1039 		engine->submit_request = i915_guc_submit;
1040 
1041 		/* Replay the current set of previously submitted requests */
1042 		list_for_each_entry(request, &engine->request_list, link) {
1043 			client->wq_rsvd += sizeof(struct guc_wq_item);
1044 			if (i915_sw_fence_done(&request->submit))
1045 				i915_guc_submit(request);
1046 		}
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
1053 {
1054 	struct intel_guc *guc = &dev_priv->guc;
1055 
1056 	if (!guc->execbuf_client)
1057 		return;
1058 
1059 	/* Revert back to manual ELSP submission */
1060 	intel_execlists_enable_submission(dev_priv);
1061 
1062 	guc_client_free(dev_priv, guc->execbuf_client);
1063 	guc->execbuf_client = NULL;
1064 }
1065 
1066 void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
1067 {
1068 	struct intel_guc *guc = &dev_priv->guc;
1069 
1070 	i915_vma_unpin_and_release(&guc->ads_vma);
1071 	i915_vma_unpin_and_release(&guc->log_vma);
1072 
1073 	if (guc->ctx_pool_vma)
1074 		ida_destroy(&guc->ctx_ids);
1075 	i915_vma_unpin_and_release(&guc->ctx_pool_vma);
1076 }
1077 
1078 /**
1079  * intel_guc_suspend() - notify GuC entering suspend state
1080  * @dev:	drm device
1081  */
1082 int intel_guc_suspend(struct drm_device *dev)
1083 {
1084 	struct drm_i915_private *dev_priv = to_i915(dev);
1085 	struct intel_guc *guc = &dev_priv->guc;
1086 	struct i915_gem_context *ctx;
1087 	u32 data[3];
1088 
1089 	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
1090 		return 0;
1091 
1092 	ctx = dev_priv->kernel_context;
1093 
1094 	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
1095 	/* any value greater than GUC_POWER_D0 */
1096 	data[1] = GUC_POWER_D1;
1097 	/* first page is shared data with GuC */
1098 	data[2] = i915_ggtt_offset(ctx->engine[RCS].state);
1099 
1100 	return host2guc_action(guc, data, ARRAY_SIZE(data));
1101 }
1102 
1103 
1104 /**
1105  * intel_guc_resume() - notify GuC resuming from suspend state
1106  * @dev:	drm device
1107  */
1108 int intel_guc_resume(struct drm_device *dev)
1109 {
1110 	struct drm_i915_private *dev_priv = to_i915(dev);
1111 	struct intel_guc *guc = &dev_priv->guc;
1112 	struct i915_gem_context *ctx;
1113 	u32 data[3];
1114 
1115 	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
1116 		return 0;
1117 
1118 	ctx = dev_priv->kernel_context;
1119 
1120 	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
1121 	data[1] = GUC_POWER_D0;
1122 	/* first page is shared data with GuC */
1123 	data[2] = i915_ggtt_offset(ctx->engine[RCS].state);
1124 
1125 	return host2guc_action(guc, data, ARRAY_SIZE(data));
1126 }
1127