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_add_workqueue_item()
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 	/* No HOST2GUC command should take longer than 10ms */
101 	ret = wait_for_atomic(host2guc_action_response(dev_priv, &status), 10);
102 	if (status != GUC2HOST_STATUS_SUCCESS) {
103 		/*
104 		 * Either the GuC explicitly returned an error (which
105 		 * we convert to -EIO here) or no response at all was
106 		 * received within the timeout limit (-ETIMEDOUT)
107 		 */
108 		if (ret != -ETIMEDOUT)
109 			ret = -EIO;
110 
111 		DRM_ERROR("GUC: host2guc action 0x%X failed. ret=%d "
112 				"status=0x%08X response=0x%08X\n",
113 				data[0], ret, status,
114 				I915_READ(SOFT_SCRATCH(15)));
115 
116 		dev_priv->guc.action_fail += 1;
117 		dev_priv->guc.action_err = ret;
118 	}
119 	dev_priv->guc.action_status = status;
120 
121 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
122 
123 	return ret;
124 }
125 
126 /*
127  * Tell the GuC to allocate or deallocate a specific doorbell
128  */
129 
130 static int host2guc_allocate_doorbell(struct intel_guc *guc,
131 				      struct i915_guc_client *client)
132 {
133 	u32 data[2];
134 
135 	data[0] = HOST2GUC_ACTION_ALLOCATE_DOORBELL;
136 	data[1] = client->ctx_index;
137 
138 	return host2guc_action(guc, data, 2);
139 }
140 
141 static int host2guc_release_doorbell(struct intel_guc *guc,
142 				     struct i915_guc_client *client)
143 {
144 	u32 data[2];
145 
146 	data[0] = HOST2GUC_ACTION_DEALLOCATE_DOORBELL;
147 	data[1] = client->ctx_index;
148 
149 	return host2guc_action(guc, data, 2);
150 }
151 
152 static int host2guc_sample_forcewake(struct intel_guc *guc,
153 				     struct i915_guc_client *client)
154 {
155 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
156 	struct drm_device *dev = dev_priv->dev;
157 	u32 data[2];
158 
159 	data[0] = HOST2GUC_ACTION_SAMPLE_FORCEWAKE;
160 	/* WaRsDisableCoarsePowerGating:skl,bxt */
161 	if (!intel_enable_rc6(dev_priv->dev) ||
162 	    IS_BXT_REVID(dev, 0, BXT_REVID_A1) ||
163 	    (IS_SKL_GT3(dev) && IS_SKL_REVID(dev, 0, SKL_REVID_E0)) ||
164 	    (IS_SKL_GT4(dev) && IS_SKL_REVID(dev, 0, SKL_REVID_E0)))
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 void guc_init_doorbell(struct intel_guc *guc,
181 			      struct i915_guc_client *client)
182 {
183 	struct guc_doorbell_info *doorbell;
184 	void *base;
185 
186 	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
187 	doorbell = (struct guc_doorbell_info *)((char *)base + client->doorbell_offset);
188 
189 	doorbell->db_status = 1;
190 	doorbell->cookie = 0;
191 
192 	kunmap_atomic(base);
193 }
194 
195 static int guc_ring_doorbell(struct i915_guc_client *gc)
196 {
197 	struct guc_process_desc *desc;
198 	union guc_doorbell_qw db_cmp, db_exc, db_ret;
199 	union guc_doorbell_qw *db;
200 	void *base;
201 	int attempt = 2, ret = -EAGAIN;
202 
203 	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0));
204 	desc = (struct guc_process_desc *)((char *)base + gc->proc_desc_offset);
205 
206 	/* Update the tail so it is visible to GuC */
207 	desc->tail = gc->wq_tail;
208 
209 	/* current cookie */
210 	db_cmp.db_status = GUC_DOORBELL_ENABLED;
211 	db_cmp.cookie = gc->cookie;
212 
213 	/* cookie to be updated */
214 	db_exc.db_status = GUC_DOORBELL_ENABLED;
215 	db_exc.cookie = gc->cookie + 1;
216 	if (db_exc.cookie == 0)
217 		db_exc.cookie = 1;
218 
219 	/* pointer of current doorbell cacheline */
220 	db = (union guc_doorbell_qw *)((char *)base + gc->doorbell_offset);
221 
222 	while (attempt--) {
223 		/* lets ring the doorbell */
224 		db_ret.value_qw = atomic64_cmpxchg((atomic64_t *)db,
225 			db_cmp.value_qw, db_exc.value_qw);
226 
227 		/* if the exchange was successfully executed */
228 		if (db_ret.value_qw == db_cmp.value_qw) {
229 			/* db was successfully rung */
230 			gc->cookie = db_exc.cookie;
231 			ret = 0;
232 			break;
233 		}
234 
235 		/* XXX: doorbell was lost and need to acquire it again */
236 		if (db_ret.db_status == GUC_DOORBELL_DISABLED)
237 			break;
238 
239 		DRM_ERROR("Cookie mismatch. Expected %d, returned %d\n",
240 			  db_cmp.cookie, db_ret.cookie);
241 
242 		/* update the cookie to newly read cookie from GuC */
243 		db_cmp.cookie = db_ret.cookie;
244 		db_exc.cookie = db_ret.cookie + 1;
245 		if (db_exc.cookie == 0)
246 			db_exc.cookie = 1;
247 	}
248 
249 	kunmap_atomic(base);
250 	return ret;
251 }
252 
253 static void guc_disable_doorbell(struct intel_guc *guc,
254 				 struct i915_guc_client *client)
255 {
256 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
257 	struct guc_doorbell_info *doorbell;
258 	void *base;
259 	i915_reg_t drbreg = GEN8_DRBREGL(client->doorbell_id);
260 	int value;
261 
262 	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
263 	doorbell = (struct guc_doorbell_info*)((char *)base + client->doorbell_offset);
264 
265 	doorbell->db_status = 0;
266 
267 	kunmap_atomic(base);
268 
269 	I915_WRITE(drbreg, I915_READ(drbreg) & ~GEN8_DRB_VALID);
270 
271 	value = I915_READ(drbreg);
272 	WARN_ON((value & GEN8_DRB_VALID) != 0);
273 
274 	I915_WRITE(GEN8_DRBREGU(client->doorbell_id), 0);
275 	I915_WRITE(drbreg, 0);
276 
277 	/* XXX: wait for any interrupts */
278 	/* XXX: wait for workqueue to drain */
279 }
280 
281 /*
282  * Select, assign and relase doorbell cachelines
283  *
284  * These functions track which doorbell cachelines are in use.
285  * The data they manipulate is protected by the host2guc lock.
286  */
287 
288 static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
289 {
290 	const uint32_t cacheline_size = cache_line_size();
291 	uint32_t offset;
292 
293 	/* Doorbell uses a single cache line within a page */
294 	offset = offset_in_page(guc->db_cacheline);
295 
296 	/* Moving to next cache line to reduce contention */
297 	guc->db_cacheline += cacheline_size;
298 
299 	DRM_DEBUG_DRIVER("selected doorbell cacheline 0x%x, next 0x%x, linesize %u\n",
300 			offset, guc->db_cacheline, cacheline_size);
301 
302 	return offset;
303 }
304 
305 static uint16_t assign_doorbell(struct intel_guc *guc, uint32_t priority)
306 {
307 	/*
308 	 * The bitmap is split into two halves; the first half is used for
309 	 * normal priority contexts, the second half for high-priority ones.
310 	 * Note that logically higher priorities are numerically less than
311 	 * normal ones, so the test below means "is it high-priority?"
312 	 */
313 	const bool hi_pri = (priority <= GUC_CTX_PRIORITY_HIGH);
314 	const uint16_t half = GUC_MAX_DOORBELLS / 2;
315 	const uint16_t start = hi_pri ? half : 0;
316 	const uint16_t end = start + half;
317 	uint16_t id;
318 
319 	id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
320 	if (id == end)
321 		id = GUC_INVALID_DOORBELL_ID;
322 	else
323 		bitmap_set(guc->doorbell_bitmap, id, 1);
324 
325 	DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
326 			hi_pri ? "high" : "normal", id);
327 
328 	return id;
329 }
330 
331 static void release_doorbell(struct intel_guc *guc, uint16_t id)
332 {
333 	bitmap_clear(guc->doorbell_bitmap, id, 1);
334 }
335 
336 /*
337  * Initialise the process descriptor shared with the GuC firmware.
338  */
339 static void guc_init_proc_desc(struct intel_guc *guc,
340 			       struct i915_guc_client *client)
341 {
342 	struct guc_process_desc *desc;
343 	void *base;
344 
345 	base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0));
346 	desc = (struct guc_process_desc *)((char *)base + client->proc_desc_offset);
347 
348 	memset(desc, 0, sizeof(*desc));
349 
350 	/*
351 	 * XXX: pDoorbell and WQVBaseAddress are pointers in process address
352 	 * space for ring3 clients (set them as in mmap_ioctl) or kernel
353 	 * space for kernel clients (map on demand instead? May make debug
354 	 * easier to have it mapped).
355 	 */
356 	desc->wq_base_addr = 0;
357 	desc->db_base_addr = 0;
358 
359 	desc->context_id = client->ctx_index;
360 	desc->wq_size_bytes = client->wq_size;
361 	desc->wq_status = WQ_STATUS_ACTIVE;
362 	desc->priority = client->priority;
363 
364 	kunmap_atomic(base);
365 }
366 
367 /*
368  * Initialise/clear the context descriptor shared with the GuC firmware.
369  *
370  * This descriptor tells the GuC where (in GGTT space) to find the important
371  * data structures relating to this client (doorbell, process descriptor,
372  * write queue, etc).
373  */
374 
375 static void guc_init_ctx_desc(struct intel_guc *guc,
376 			      struct i915_guc_client *client)
377 {
378 	struct intel_context *ctx = client->owner;
379 	struct guc_context_desc desc;
380 	struct sg_table *sg;
381 	int i;
382 
383 	memset(&desc, 0, sizeof(desc));
384 
385 	desc.attribute = GUC_CTX_DESC_ATTR_ACTIVE | GUC_CTX_DESC_ATTR_KERNEL;
386 	desc.context_id = client->ctx_index;
387 	desc.priority = client->priority;
388 	desc.db_id = client->doorbell_id;
389 
390 	for (i = 0; i < I915_NUM_RINGS; i++) {
391 		struct guc_execlist_context *lrc = &desc.lrc[i];
392 		struct intel_ringbuffer *ringbuf = ctx->engine[i].ringbuf;
393 		struct intel_engine_cs *ring;
394 		struct drm_i915_gem_object *obj;
395 		uint64_t ctx_desc;
396 
397 		/* TODO: We have a design issue to be solved here. Only when we
398 		 * receive the first batch, we know which engine is used by the
399 		 * user. But here GuC expects the lrc and ring to be pinned. It
400 		 * is not an issue for default context, which is the only one
401 		 * for now who owns a GuC client. But for future owner of GuC
402 		 * client, need to make sure lrc is pinned prior to enter here.
403 		 */
404 		obj = ctx->engine[i].state;
405 		if (!obj)
406 			break;	/* XXX: continue? */
407 
408 		ring = ringbuf->ring;
409 		ctx_desc = intel_lr_context_descriptor(ctx, ring);
410 		lrc->context_desc = (u32)ctx_desc;
411 
412 		/* The state page is after PPHWSP */
413 		lrc->ring_lcra = i915_gem_obj_ggtt_offset(obj) +
414 				LRC_STATE_PN * PAGE_SIZE;
415 		lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) |
416 				(ring->id << GUC_ELC_ENGINE_OFFSET);
417 
418 		obj = ringbuf->obj;
419 
420 		lrc->ring_begin = i915_gem_obj_ggtt_offset(obj);
421 		lrc->ring_end = lrc->ring_begin + obj->base.size - 1;
422 		lrc->ring_next_free_location = lrc->ring_begin;
423 		lrc->ring_current_tail_pointer_value = 0;
424 
425 		desc.engines_used |= (1 << ring->id);
426 	}
427 
428 	WARN_ON(desc.engines_used == 0);
429 
430 	/*
431 	 * The CPU address is only needed at certain points, so kmap_atomic on
432 	 * demand instead of storing it in the ctx descriptor.
433 	 * XXX: May make debug easier to have it mapped
434 	 */
435 	desc.db_trigger_cpu = 0;
436 	desc.db_trigger_uk = client->doorbell_offset +
437 		i915_gem_obj_ggtt_offset(client->client_obj);
438 	desc.db_trigger_phy = client->doorbell_offset +
439 		sg_dma_address(client->client_obj->pages->sgl);
440 
441 	desc.process_desc = client->proc_desc_offset +
442 		i915_gem_obj_ggtt_offset(client->client_obj);
443 
444 	desc.wq_addr = client->wq_offset +
445 		i915_gem_obj_ggtt_offset(client->client_obj);
446 
447 	desc.wq_size = client->wq_size;
448 
449 	/*
450 	 * XXX: Take LRCs from an existing intel_context if this is not an
451 	 * IsKMDCreatedContext client
452 	 */
453 	desc.desc_private = (uintptr_t)client;
454 
455 	/* Pool context is pinned already */
456 	sg = guc->ctx_pool_obj->pages;
457 	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
458 			     sizeof(desc) * client->ctx_index);
459 }
460 
461 static void guc_fini_ctx_desc(struct intel_guc *guc,
462 			      struct i915_guc_client *client)
463 {
464 	struct guc_context_desc desc;
465 	struct sg_table *sg;
466 
467 	memset(&desc, 0, sizeof(desc));
468 
469 	sg = guc->ctx_pool_obj->pages;
470 	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
471 			     sizeof(desc) * client->ctx_index);
472 }
473 
474 /* Get valid workqueue item and return it back to offset */
475 static int guc_get_workqueue_space(struct i915_guc_client *gc, u32 *offset)
476 {
477 	struct guc_process_desc *desc;
478 	void *base;
479 	u32 size = sizeof(struct guc_wq_item);
480 	int ret = -ETIMEDOUT, timeout_counter = 200;
481 
482 	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0));
483 	desc = (struct guc_process_desc *)((char *)base + gc->proc_desc_offset);
484 
485 	while (timeout_counter-- > 0) {
486 		if (CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size) >= size) {
487 			*offset = gc->wq_tail;
488 
489 			/* advance the tail for next workqueue item */
490 			gc->wq_tail += size;
491 			gc->wq_tail &= gc->wq_size - 1;
492 
493 			/* this will break the loop */
494 			timeout_counter = 0;
495 			ret = 0;
496 		}
497 
498 		if (timeout_counter)
499 			usleep_range(1000, 2000);
500 	};
501 
502 	kunmap_atomic(base);
503 
504 	return ret;
505 }
506 
507 static int guc_add_workqueue_item(struct i915_guc_client *gc,
508 				  struct drm_i915_gem_request *rq)
509 {
510 	enum intel_ring_id ring_id = rq->ring->id;
511 	struct guc_wq_item *wqi;
512 	void *base;
513 	u32 tail, wq_len, wq_off = 0;
514 	int ret;
515 
516 	ret = guc_get_workqueue_space(gc, &wq_off);
517 	if (ret)
518 		return ret;
519 
520 	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
521 	 * should not have the case where structure wqi is across page, neither
522 	 * wrapped to the beginning. This simplifies the implementation below.
523 	 *
524 	 * XXX: if not the case, we need save data to a temp wqi and copy it to
525 	 * workqueue buffer dw by dw.
526 	 */
527 	WARN_ON(sizeof(struct guc_wq_item) != 16);
528 	WARN_ON(wq_off & 3);
529 
530 	/* wq starts from the page after doorbell / process_desc */
531 	base = kmap_atomic(i915_gem_object_get_page(gc->client_obj,
532 			(wq_off + GUC_DB_SIZE) >> PAGE_SHIFT));
533 	wq_off &= PAGE_SIZE - 1;
534 	wqi = (struct guc_wq_item *)((char *)base + wq_off);
535 
536 	/* len does not include the header */
537 	wq_len = sizeof(struct guc_wq_item) / sizeof(u32) - 1;
538 	wqi->header = WQ_TYPE_INORDER |
539 			(wq_len << WQ_LEN_SHIFT) |
540 			(ring_id << WQ_TARGET_SHIFT) |
541 			WQ_NO_WCFLUSH_WAIT;
542 
543 	/* The GuC wants only the low-order word of the context descriptor */
544 	wqi->context_desc = (u32)intel_lr_context_descriptor(rq->ctx, rq->ring);
545 
546 	/* The GuC firmware wants the tail index in QWords, not bytes */
547 	tail = rq->ringbuf->tail >> 3;
548 	wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT;
549 	wqi->fence_id = 0; /*XXX: what fence to be here */
550 
551 	kunmap_atomic(base);
552 
553 	return 0;
554 }
555 
556 #define CTX_RING_BUFFER_START		0x08
557 
558 /* Update the ringbuffer pointer in a saved context image */
559 static void lr_context_update(struct drm_i915_gem_request *rq)
560 {
561 	enum intel_ring_id ring_id = rq->ring->id;
562 	struct drm_i915_gem_object *ctx_obj = rq->ctx->engine[ring_id].state;
563 	struct drm_i915_gem_object *rb_obj = rq->ringbuf->obj;
564 	struct vm_page *page;
565 	uint32_t *reg_state;
566 
567 	BUG_ON(!ctx_obj);
568 	WARN_ON(!i915_gem_obj_is_pinned(ctx_obj));
569 	WARN_ON(!i915_gem_obj_is_pinned(rb_obj));
570 
571 	page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
572 	reg_state = kmap_atomic(page);
573 
574 	reg_state[CTX_RING_BUFFER_START+1] = i915_gem_obj_ggtt_offset(rb_obj);
575 
576 	kunmap_atomic(reg_state);
577 }
578 
579 /**
580  * i915_guc_submit() - Submit commands through GuC
581  * @client:	the guc client where commands will go through
582  * @rq:		request associated with the commands
583  *
584  * Return:	0 if succeed
585  */
586 int i915_guc_submit(struct i915_guc_client *client,
587 		    struct drm_i915_gem_request *rq)
588 {
589 	struct intel_guc *guc = client->guc;
590 	enum intel_ring_id ring_id = rq->ring->id;
591 	int q_ret, b_ret;
592 
593 	/* Need this because of the deferred pin ctx and ring */
594 	/* Shall we move this right after ring is pinned? */
595 	lr_context_update(rq);
596 
597 	q_ret = guc_add_workqueue_item(client, rq);
598 	if (q_ret == 0)
599 		b_ret = guc_ring_doorbell(client);
600 
601 	client->submissions[ring_id] += 1;
602 	if (q_ret) {
603 		client->q_fail += 1;
604 		client->retcode = q_ret;
605 	} else if (b_ret) {
606 		client->b_fail += 1;
607 		client->retcode = q_ret = b_ret;
608 	} else {
609 		client->retcode = 0;
610 	}
611 	guc->submissions[ring_id] += 1;
612 	guc->last_seqno[ring_id] = rq->seqno;
613 
614 	return q_ret;
615 }
616 
617 /*
618  * Everything below here is concerned with setup & teardown, and is
619  * therefore not part of the somewhat time-critical batch-submission
620  * path of i915_guc_submit() above.
621  */
622 
623 /**
624  * gem_allocate_guc_obj() - Allocate gem object for GuC usage
625  * @dev:	drm device
626  * @size:	size of object
627  *
628  * This is a wrapper to create a gem obj. In order to use it inside GuC, the
629  * object needs to be pinned lifetime. Also we must pin it to gtt space other
630  * than [0, GUC_WOPCM_TOP) because this range is reserved inside GuC.
631  *
632  * Return:	A drm_i915_gem_object if successful, otherwise NULL.
633  */
634 static struct drm_i915_gem_object *gem_allocate_guc_obj(struct drm_device *dev,
635 							u32 size)
636 {
637 	struct drm_i915_private *dev_priv = dev->dev_private;
638 	struct drm_i915_gem_object *obj;
639 
640 	obj = i915_gem_alloc_object(dev, size);
641 	if (!obj)
642 		return NULL;
643 
644 	if (i915_gem_object_get_pages(obj)) {
645 		drm_gem_object_unreference(&obj->base);
646 		return NULL;
647 	}
648 
649 	if (i915_gem_obj_ggtt_pin(obj, PAGE_SIZE,
650 			PIN_OFFSET_BIAS | GUC_WOPCM_TOP)) {
651 		drm_gem_object_unreference(&obj->base);
652 		return NULL;
653 	}
654 
655 	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
656 	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);
657 
658 	return obj;
659 }
660 
661 /**
662  * gem_release_guc_obj() - Release gem object allocated for GuC usage
663  * @obj:	gem obj to be released
664  */
665 static void gem_release_guc_obj(struct drm_i915_gem_object *obj)
666 {
667 	if (!obj)
668 		return;
669 
670 	if (i915_gem_obj_is_pinned(obj))
671 		i915_gem_object_ggtt_unpin(obj);
672 
673 	drm_gem_object_unreference(&obj->base);
674 }
675 
676 static void guc_client_free(struct drm_device *dev,
677 			    struct i915_guc_client *client)
678 {
679 	struct drm_i915_private *dev_priv = dev->dev_private;
680 	struct intel_guc *guc = &dev_priv->guc;
681 
682 	if (!client)
683 		return;
684 
685 	if (client->doorbell_id != GUC_INVALID_DOORBELL_ID) {
686 		/*
687 		 * First disable the doorbell, then tell the GuC we've
688 		 * finished with it, finally deallocate it in our bitmap
689 		 */
690 		guc_disable_doorbell(guc, client);
691 		host2guc_release_doorbell(guc, client);
692 		release_doorbell(guc, client->doorbell_id);
693 	}
694 
695 	/*
696 	 * XXX: wait for any outstanding submissions before freeing memory.
697 	 * Be sure to drop any locks
698 	 */
699 
700 	gem_release_guc_obj(client->client_obj);
701 
702 	if (client->ctx_index != GUC_INVALID_CTX_ID) {
703 		guc_fini_ctx_desc(guc, client);
704 		ida_simple_remove(&guc->ctx_ids, client->ctx_index);
705 	}
706 
707 	kfree(client);
708 }
709 
710 /**
711  * guc_client_alloc() - Allocate an i915_guc_client
712  * @dev:	drm device
713  * @priority:	four levels priority _CRITICAL, _HIGH, _NORMAL and _LOW
714  * 		The kernel client to replace ExecList submission is created with
715  * 		NORMAL priority. Priority of a client for scheduler can be HIGH,
716  * 		while a preemption context can use CRITICAL.
717  * @ctx:	the context that owns the client (we use the default render
718  * 		context)
719  *
720  * Return:	An i915_guc_client object if success.
721  */
722 static struct i915_guc_client *guc_client_alloc(struct drm_device *dev,
723 						uint32_t priority,
724 						struct intel_context *ctx)
725 {
726 	struct i915_guc_client *client;
727 	struct drm_i915_private *dev_priv = dev->dev_private;
728 	struct intel_guc *guc = &dev_priv->guc;
729 	struct drm_i915_gem_object *obj;
730 
731 	client = kzalloc(sizeof(*client), GFP_KERNEL);
732 	if (!client)
733 		return NULL;
734 
735 	client->doorbell_id = GUC_INVALID_DOORBELL_ID;
736 	client->priority = priority;
737 	client->owner = ctx;
738 	client->guc = guc;
739 
740 	client->ctx_index = (uint32_t)ida_simple_get(&guc->ctx_ids, 0,
741 			GUC_MAX_GPU_CONTEXTS, GFP_KERNEL);
742 	if (client->ctx_index >= GUC_MAX_GPU_CONTEXTS) {
743 		client->ctx_index = GUC_INVALID_CTX_ID;
744 		goto err;
745 	}
746 
747 	/* The first page is doorbell/proc_desc. Two followed pages are wq. */
748 	obj = gem_allocate_guc_obj(dev, GUC_DB_SIZE + GUC_WQ_SIZE);
749 	if (!obj)
750 		goto err;
751 
752 	client->client_obj = obj;
753 	client->wq_offset = GUC_DB_SIZE;
754 	client->wq_size = GUC_WQ_SIZE;
755 
756 	client->doorbell_offset = select_doorbell_cacheline(guc);
757 
758 	/*
759 	 * Since the doorbell only requires a single cacheline, we can save
760 	 * space by putting the application process descriptor in the same
761 	 * page. Use the half of the page that doesn't include the doorbell.
762 	 */
763 	if (client->doorbell_offset >= (GUC_DB_SIZE / 2))
764 		client->proc_desc_offset = 0;
765 	else
766 		client->proc_desc_offset = (GUC_DB_SIZE / 2);
767 
768 	client->doorbell_id = assign_doorbell(guc, client->priority);
769 	if (client->doorbell_id == GUC_INVALID_DOORBELL_ID)
770 		/* XXX: evict a doorbell instead */
771 		goto err;
772 
773 	guc_init_proc_desc(guc, client);
774 	guc_init_ctx_desc(guc, client);
775 	guc_init_doorbell(guc, client);
776 
777 	/* XXX: Any cache flushes needed? General domain mgmt calls? */
778 
779 	if (host2guc_allocate_doorbell(guc, client))
780 		goto err;
781 
782 	DRM_DEBUG_DRIVER("new priority %u client %p: ctx_index %u db_id %u\n",
783 		priority, client, client->ctx_index, client->doorbell_id);
784 
785 	return client;
786 
787 err:
788 	DRM_ERROR("FAILED to create priority %u GuC client!\n", priority);
789 
790 	guc_client_free(dev, client);
791 	return NULL;
792 }
793 
794 static void guc_create_log(struct intel_guc *guc)
795 {
796 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
797 	struct drm_i915_gem_object *obj;
798 	unsigned long offset;
799 	uint32_t size, flags;
800 
801 	if (i915.guc_log_level < GUC_LOG_VERBOSITY_MIN)
802 		return;
803 
804 	if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
805 		i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;
806 
807 	/* The first page is to save log buffer state. Allocate one
808 	 * extra page for others in case for overlap */
809 	size = (1 + GUC_LOG_DPC_PAGES + 1 +
810 		GUC_LOG_ISR_PAGES + 1 +
811 		GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
812 
813 	obj = guc->log_obj;
814 	if (!obj) {
815 		obj = gem_allocate_guc_obj(dev_priv->dev, size);
816 		if (!obj) {
817 			/* logging will be off */
818 			i915.guc_log_level = -1;
819 			return;
820 		}
821 
822 		guc->log_obj = obj;
823 	}
824 
825 	/* each allocated unit is a page */
826 	flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
827 		(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
828 		(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
829 		(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
830 
831 	offset = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT; /* in pages */
832 	guc->log_flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
833 }
834 
835 /*
836  * Set up the memory resources to be shared with the GuC.  At this point,
837  * we require just one object that can be mapped through the GGTT.
838  */
839 int i915_guc_submission_init(struct drm_device *dev)
840 {
841 	struct drm_i915_private *dev_priv = dev->dev_private;
842 	const size_t ctxsize = sizeof(struct guc_context_desc);
843 	const size_t poolsize = GUC_MAX_GPU_CONTEXTS * ctxsize;
844 	const size_t gemsize = round_up(poolsize, PAGE_SIZE);
845 	struct intel_guc *guc = &dev_priv->guc;
846 
847 	if (!i915.enable_guc_submission)
848 		return 0; /* not enabled  */
849 
850 	if (guc->ctx_pool_obj)
851 		return 0; /* already allocated */
852 
853 	guc->ctx_pool_obj = gem_allocate_guc_obj(dev_priv->dev, gemsize);
854 	if (!guc->ctx_pool_obj)
855 		return -ENOMEM;
856 
857 	ida_init(&guc->ctx_ids);
858 
859 	guc_create_log(guc);
860 
861 	return 0;
862 }
863 
864 int i915_guc_submission_enable(struct drm_device *dev)
865 {
866 	struct drm_i915_private *dev_priv = dev->dev_private;
867 	struct intel_guc *guc = &dev_priv->guc;
868 	struct intel_context *ctx = dev_priv->ring[RCS].default_context;
869 	struct i915_guc_client *client;
870 
871 	/* client for execbuf submission */
872 	client = guc_client_alloc(dev, GUC_CTX_PRIORITY_KMD_NORMAL, ctx);
873 	if (!client) {
874 		DRM_ERROR("Failed to create execbuf guc_client\n");
875 		return -ENOMEM;
876 	}
877 
878 	guc->execbuf_client = client;
879 
880 	host2guc_sample_forcewake(guc, client);
881 
882 	return 0;
883 }
884 
885 void i915_guc_submission_disable(struct drm_device *dev)
886 {
887 	struct drm_i915_private *dev_priv = dev->dev_private;
888 	struct intel_guc *guc = &dev_priv->guc;
889 
890 	guc_client_free(dev, guc->execbuf_client);
891 	guc->execbuf_client = NULL;
892 }
893 
894 void i915_guc_submission_fini(struct drm_device *dev)
895 {
896 	struct drm_i915_private *dev_priv = dev->dev_private;
897 	struct intel_guc *guc = &dev_priv->guc;
898 
899 	gem_release_guc_obj(dev_priv->guc.log_obj);
900 	guc->log_obj = NULL;
901 
902 	if (guc->ctx_pool_obj)
903 		ida_destroy(&guc->ctx_ids);
904 	gem_release_guc_obj(guc->ctx_pool_obj);
905 	guc->ctx_pool_obj = NULL;
906 }
907 
908 /**
909  * intel_guc_suspend() - notify GuC entering suspend state
910  * @dev:	drm device
911  */
912 int intel_guc_suspend(struct drm_device *dev)
913 {
914 	struct drm_i915_private *dev_priv = dev->dev_private;
915 	struct intel_guc *guc = &dev_priv->guc;
916 	struct intel_context *ctx;
917 	u32 data[3];
918 
919 	if (!i915.enable_guc_submission)
920 		return 0;
921 
922 	ctx = dev_priv->ring[RCS].default_context;
923 
924 	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
925 	/* any value greater than GUC_POWER_D0 */
926 	data[1] = GUC_POWER_D1;
927 	/* first page is shared data with GuC */
928 	data[2] = i915_gem_obj_ggtt_offset(ctx->engine[RCS].state);
929 
930 	return host2guc_action(guc, data, ARRAY_SIZE(data));
931 }
932 
933 
934 /**
935  * intel_guc_resume() - notify GuC resuming from suspend state
936  * @dev:	drm device
937  */
938 int intel_guc_resume(struct drm_device *dev)
939 {
940 	struct drm_i915_private *dev_priv = dev->dev_private;
941 	struct intel_guc *guc = &dev_priv->guc;
942 	struct intel_context *ctx;
943 	u32 data[3];
944 
945 	if (!i915.enable_guc_submission)
946 		return 0;
947 
948 	ctx = dev_priv->ring[RCS].default_context;
949 
950 	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
951 	data[1] = GUC_POWER_D0;
952 	/* first page is shared data with GuC */
953 	data[2] = i915_gem_obj_ggtt_offset(ctx->engine[RCS].state);
954 
955 	return host2guc_action(guc, data, ARRAY_SIZE(data));
956 }
957