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 
25 #include <linux/circ_buf.h>
26 #include <trace/events/dma_fence.h>
27 
28 #include "i915_guc_submission.h"
29 #include "i915_drv.h"
30 
31 /**
32  * DOC: GuC-based command submission
33  *
34  * GuC client:
35  * A i915_guc_client refers to a submission path through GuC. Currently, there
36  * is only one of these (the execbuf_client) and this one is charged with all
37  * submissions to the GuC. This struct is the owner of a doorbell, a process
38  * descriptor and a workqueue (all of them inside a single gem object that
39  * contains all required pages for these elements).
40  *
41  * GuC stage descriptor:
42  * During initialization, the driver allocates a static pool of 1024 such
43  * descriptors, and shares them with the GuC.
44  * Currently, there exists a 1:1 mapping between a i915_guc_client and a
45  * guc_stage_desc (via the client's stage_id), so effectively only one
46  * gets used. This stage descriptor lets the GuC know about the doorbell,
47  * workqueue and process descriptor. Theoretically, it also lets the GuC
48  * know about our HW contexts (context ID, etc...), but we actually
49  * employ a kind of submission where the GuC uses the LRCA sent via the work
50  * item instead (the single guc_stage_desc associated to execbuf client
51  * contains information about the default kernel context only, but this is
52  * essentially unused). This is called a "proxy" submission.
53  *
54  * The Scratch registers:
55  * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes
56  * a value to the action register (SOFT_SCRATCH_0) along with any data. It then
57  * triggers an interrupt on the GuC via another register write (0xC4C8).
58  * Firmware writes a success/fail code back to the action register after
59  * processes the request. The kernel driver polls waiting for this update and
60  * then proceeds.
61  * See intel_guc_send()
62  *
63  * Doorbells:
64  * Doorbells are interrupts to uKernel. A doorbell is a single cache line (QW)
65  * mapped into process space.
66  *
67  * Work Items:
68  * There are several types of work items that the host may place into a
69  * workqueue, each with its own requirements and limitations. Currently only
70  * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which
71  * represents in-order queue. The kernel driver packs ring tail pointer and an
72  * ELSP context descriptor dword into Work Item.
73  * See guc_wq_item_append()
74  *
75  * ADS:
76  * The Additional Data Struct (ADS) has pointers for different buffers used by
77  * the GuC. One single gem object contains the ADS struct itself (guc_ads), the
78  * scheduling policies (guc_policies), a structure describing a collection of
79  * register sets (guc_mmio_reg_state) and some extra pages for the GuC to save
80  * its internal state for sleep.
81  *
82  */
83 
84 static inline bool is_high_priority(struct i915_guc_client* client)
85 {
86 	return client->priority <= GUC_CLIENT_PRIORITY_HIGH;
87 }
88 
89 static int __reserve_doorbell(struct i915_guc_client *client)
90 {
91 	unsigned long offset;
92 	unsigned long end;
93 	u16 id;
94 
95 	GEM_BUG_ON(client->doorbell_id != GUC_DOORBELL_INVALID);
96 
97 	/*
98 	 * The bitmap tracks which doorbell registers are currently in use.
99 	 * It is split into two halves; the first half is used for normal
100 	 * priority contexts, the second half for high-priority ones.
101 	 */
102 	offset = 0;
103 	end = GUC_NUM_DOORBELLS/2;
104 	if (is_high_priority(client)) {
105 		offset = end;
106 		end += offset;
107 	}
108 
109 	id = find_next_zero_bit(client->guc->doorbell_bitmap, end, offset);
110 	if (id == end)
111 		return -ENOSPC;
112 
113 	__set_bit(id, client->guc->doorbell_bitmap);
114 	client->doorbell_id = id;
115 	DRM_DEBUG_DRIVER("client %u (high prio=%s) reserved doorbell: %d\n",
116 			 client->stage_id, yesno(is_high_priority(client)),
117 			 id);
118 	return 0;
119 }
120 
121 static void __unreserve_doorbell(struct i915_guc_client *client)
122 {
123 	GEM_BUG_ON(client->doorbell_id == GUC_DOORBELL_INVALID);
124 
125 	__clear_bit(client->doorbell_id, client->guc->doorbell_bitmap);
126 	client->doorbell_id = GUC_DOORBELL_INVALID;
127 }
128 
129 /*
130  * Tell the GuC to allocate or deallocate a specific doorbell
131  */
132 
133 static int __guc_allocate_doorbell(struct intel_guc *guc, u32 stage_id)
134 {
135 	u32 action[] = {
136 		INTEL_GUC_ACTION_ALLOCATE_DOORBELL,
137 		stage_id
138 	};
139 
140 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
141 }
142 
143 static int __guc_deallocate_doorbell(struct intel_guc *guc, u32 stage_id)
144 {
145 	u32 action[] = {
146 		INTEL_GUC_ACTION_DEALLOCATE_DOORBELL,
147 		stage_id
148 	};
149 
150 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
151 }
152 
153 static struct guc_stage_desc *__get_stage_desc(struct i915_guc_client *client)
154 {
155 	struct guc_stage_desc *base = client->guc->stage_desc_pool_vaddr;
156 
157 	return &base[client->stage_id];
158 }
159 
160 /*
161  * Initialise, update, or clear doorbell data shared with the GuC
162  *
163  * These functions modify shared data and so need access to the mapped
164  * client object which contains the page being used for the doorbell
165  */
166 
167 static void __update_doorbell_desc(struct i915_guc_client *client, u16 new_id)
168 {
169 	struct guc_stage_desc *desc;
170 
171 	/* Update the GuC's idea of the doorbell ID */
172 	desc = __get_stage_desc(client);
173 	desc->db_id = new_id;
174 }
175 
176 static struct guc_doorbell_info *__get_doorbell(struct i915_guc_client *client)
177 {
178 	return client->vaddr + client->doorbell_offset;
179 }
180 
181 static bool has_doorbell(struct i915_guc_client *client)
182 {
183 	if (client->doorbell_id == GUC_DOORBELL_INVALID)
184 		return false;
185 
186 	return test_bit(client->doorbell_id, client->guc->doorbell_bitmap);
187 }
188 
189 static int __create_doorbell(struct i915_guc_client *client)
190 {
191 	struct guc_doorbell_info *doorbell;
192 	int err;
193 
194 	doorbell = __get_doorbell(client);
195 	doorbell->db_status = GUC_DOORBELL_ENABLED;
196 	doorbell->cookie = 0;
197 
198 	err = __guc_allocate_doorbell(client->guc, client->stage_id);
199 	if (err)
200 		doorbell->db_status = GUC_DOORBELL_DISABLED;
201 
202 	return err;
203 }
204 
205 static int __destroy_doorbell(struct i915_guc_client *client)
206 {
207 	struct drm_i915_private *dev_priv = guc_to_i915(client->guc);
208 	struct guc_doorbell_info *doorbell;
209 	u16 db_id = client->doorbell_id;
210 
211 	GEM_BUG_ON(db_id >= GUC_DOORBELL_INVALID);
212 
213 	doorbell = __get_doorbell(client);
214 	doorbell->db_status = GUC_DOORBELL_DISABLED;
215 	doorbell->cookie = 0;
216 
217 	/* Doorbell release flow requires that we wait for GEN8_DRB_VALID bit
218 	 * to go to zero after updating db_status before we call the GuC to
219 	 * release the doorbell */
220 	if (wait_for_us(!(I915_READ(GEN8_DRBREGL(db_id)) & GEN8_DRB_VALID), 10))
221 		WARN_ONCE(true, "Doorbell never became invalid after disable\n");
222 
223 	return __guc_deallocate_doorbell(client->guc, client->stage_id);
224 }
225 
226 static int create_doorbell(struct i915_guc_client *client)
227 {
228 	int ret;
229 
230 	ret = __reserve_doorbell(client);
231 	if (ret)
232 		return ret;
233 
234 	__update_doorbell_desc(client, client->doorbell_id);
235 
236 	ret = __create_doorbell(client);
237 	if (ret)
238 		goto err;
239 
240 	return 0;
241 
242 err:
243 	__update_doorbell_desc(client, GUC_DOORBELL_INVALID);
244 	__unreserve_doorbell(client);
245 	return ret;
246 }
247 
248 static int destroy_doorbell(struct i915_guc_client *client)
249 {
250 	int err;
251 
252 	GEM_BUG_ON(!has_doorbell(client));
253 
254 	/* XXX: wait for any interrupts */
255 	/* XXX: wait for workqueue to drain */
256 
257 	err = __destroy_doorbell(client);
258 	if (err)
259 		return err;
260 
261 	__update_doorbell_desc(client, GUC_DOORBELL_INVALID);
262 
263 	__unreserve_doorbell(client);
264 
265 	return 0;
266 }
267 
268 static unsigned long __select_cacheline(struct intel_guc* guc)
269 {
270 	unsigned long offset;
271 
272 	/* Doorbell uses a single cache line within a page */
273 	offset = offset_in_page(guc->db_cacheline);
274 
275 	/* Moving to next cache line to reduce contention */
276 	guc->db_cacheline += cache_line_size();
277 
278 	DRM_DEBUG_DRIVER("reserved cacheline 0x%lx, next 0x%x, linesize %u\n",
279 			offset, guc->db_cacheline, cache_line_size());
280 	return offset;
281 }
282 
283 static inline struct guc_process_desc *
284 __get_process_desc(struct i915_guc_client *client)
285 {
286 	return client->vaddr + client->proc_desc_offset;
287 }
288 
289 /*
290  * Initialise the process descriptor shared with the GuC firmware.
291  */
292 static void guc_proc_desc_init(struct intel_guc *guc,
293 			       struct i915_guc_client *client)
294 {
295 	struct guc_process_desc *desc;
296 
297 	desc = memset(__get_process_desc(client), 0, sizeof(*desc));
298 
299 	/*
300 	 * XXX: pDoorbell and WQVBaseAddress are pointers in process address
301 	 * space for ring3 clients (set them as in mmap_ioctl) or kernel
302 	 * space for kernel clients (map on demand instead? May make debug
303 	 * easier to have it mapped).
304 	 */
305 	desc->wq_base_addr = 0;
306 	desc->db_base_addr = 0;
307 
308 	desc->stage_id = client->stage_id;
309 	desc->wq_size_bytes = GUC_WQ_SIZE;
310 	desc->wq_status = WQ_STATUS_ACTIVE;
311 	desc->priority = client->priority;
312 }
313 
314 /*
315  * Initialise/clear the stage descriptor shared with the GuC firmware.
316  *
317  * This descriptor tells the GuC where (in GGTT space) to find the important
318  * data structures relating to this client (doorbell, process descriptor,
319  * write queue, etc).
320  */
321 static void guc_stage_desc_init(struct intel_guc *guc,
322 				struct i915_guc_client *client)
323 {
324 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
325 	struct intel_engine_cs *engine;
326 	struct i915_gem_context *ctx = client->owner;
327 	struct guc_stage_desc *desc;
328 	unsigned int tmp;
329 	u32 gfx_addr;
330 
331 	desc = __get_stage_desc(client);
332 	memset(desc, 0, sizeof(*desc));
333 
334 	desc->attribute = GUC_STAGE_DESC_ATTR_ACTIVE | GUC_STAGE_DESC_ATTR_KERNEL;
335 	desc->stage_id = client->stage_id;
336 	desc->priority = client->priority;
337 	desc->db_id = client->doorbell_id;
338 
339 	for_each_engine_masked(engine, dev_priv, client->engines, tmp) {
340 		struct intel_context *ce = &ctx->engine[engine->id];
341 		u32 guc_engine_id = engine->guc_id;
342 		struct guc_execlist_context *lrc = &desc->lrc[guc_engine_id];
343 
344 		/* TODO: We have a design issue to be solved here. Only when we
345 		 * receive the first batch, we know which engine is used by the
346 		 * user. But here GuC expects the lrc and ring to be pinned. It
347 		 * is not an issue for default context, which is the only one
348 		 * for now who owns a GuC client. But for future owner of GuC
349 		 * client, need to make sure lrc is pinned prior to enter here.
350 		 */
351 		if (!ce->state)
352 			break;	/* XXX: continue? */
353 
354 		/*
355 		 * XXX: When this is a GUC_STAGE_DESC_ATTR_KERNEL client (proxy
356 		 * submission or, in other words, not using a direct submission
357 		 * model) the KMD's LRCA is not used for any work submission.
358 		 * Instead, the GuC uses the LRCA of the user mode context (see
359 		 * guc_wq_item_append below).
360 		 */
361 		lrc->context_desc = lower_32_bits(ce->lrc_desc);
362 
363 		/* The state page is after PPHWSP */
364 		lrc->ring_lrca =
365 			guc_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE;
366 
367 		/* XXX: In direct submission, the GuC wants the HW context id
368 		 * here. In proxy submission, it wants the stage id */
369 		lrc->context_id = (client->stage_id << GUC_ELC_CTXID_OFFSET) |
370 				(guc_engine_id << GUC_ELC_ENGINE_OFFSET);
371 
372 		lrc->ring_begin = guc_ggtt_offset(ce->ring->vma);
373 		lrc->ring_end = lrc->ring_begin + ce->ring->size - 1;
374 		lrc->ring_next_free_location = lrc->ring_begin;
375 		lrc->ring_current_tail_pointer_value = 0;
376 
377 		desc->engines_used |= (1 << guc_engine_id);
378 	}
379 
380 	DRM_DEBUG_DRIVER("Host engines 0x%x => GuC engines used 0x%x\n",
381 			client->engines, desc->engines_used);
382 	WARN_ON(desc->engines_used == 0);
383 
384 	/*
385 	 * The doorbell, process descriptor, and workqueue are all parts
386 	 * of the client object, which the GuC will reference via the GGTT
387 	 */
388 	gfx_addr = guc_ggtt_offset(client->vma);
389 	desc->db_trigger_phy = sg_dma_address(client->vma->pages->sgl) +
390 				client->doorbell_offset;
391 	desc->db_trigger_cpu = ptr_to_u64(__get_doorbell(client));
392 	desc->db_trigger_uk = gfx_addr + client->doorbell_offset;
393 	desc->process_desc = gfx_addr + client->proc_desc_offset;
394 	desc->wq_addr = gfx_addr + GUC_DB_SIZE;
395 	desc->wq_size = GUC_WQ_SIZE;
396 
397 	desc->desc_private = ptr_to_u64(client);
398 }
399 
400 static void guc_stage_desc_fini(struct intel_guc *guc,
401 				struct i915_guc_client *client)
402 {
403 	struct guc_stage_desc *desc;
404 
405 	desc = __get_stage_desc(client);
406 	memset(desc, 0, sizeof(*desc));
407 }
408 
409 /* Construct a Work Item and append it to the GuC's Work Queue */
410 static void guc_wq_item_append(struct i915_guc_client *client,
411 			       struct drm_i915_gem_request *rq)
412 {
413 	/* wqi_len is in DWords, and does not include the one-word header */
414 	const size_t wqi_size = sizeof(struct guc_wq_item);
415 	const u32 wqi_len = wqi_size / sizeof(u32) - 1;
416 	struct intel_engine_cs *engine = rq->engine;
417 	struct i915_gem_context *ctx = rq->ctx;
418 	struct guc_process_desc *desc = __get_process_desc(client);
419 	struct guc_wq_item *wqi;
420 	u32 ring_tail, wq_off;
421 
422 	lockdep_assert_held(&client->wq_lock);
423 
424 	ring_tail = intel_ring_set_tail(rq->ring, rq->tail) / sizeof(u64);
425 	GEM_BUG_ON(ring_tail > WQ_RING_TAIL_MAX);
426 
427 	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
428 	 * should not have the case where structure wqi is across page, neither
429 	 * wrapped to the beginning. This simplifies the implementation below.
430 	 *
431 	 * XXX: if not the case, we need save data to a temp wqi and copy it to
432 	 * workqueue buffer dw by dw.
433 	 */
434 	BUILD_BUG_ON(wqi_size != 16);
435 
436 	/* Free space is guaranteed. */
437 	wq_off = READ_ONCE(desc->tail);
438 	GEM_BUG_ON(CIRC_SPACE(wq_off, READ_ONCE(desc->head),
439 			      GUC_WQ_SIZE) < wqi_size);
440 	GEM_BUG_ON(wq_off & (wqi_size - 1));
441 
442 	/* WQ starts from the page after doorbell / process_desc */
443 	wqi = client->vaddr + wq_off + GUC_DB_SIZE;
444 
445 	/* Now fill in the 4-word work queue item */
446 	wqi->header = WQ_TYPE_INORDER |
447 		      (wqi_len << WQ_LEN_SHIFT) |
448 		      (engine->guc_id << WQ_TARGET_SHIFT) |
449 		      WQ_NO_WCFLUSH_WAIT;
450 
451 	wqi->context_desc = lower_32_bits(intel_lr_context_descriptor(ctx, engine));
452 
453 	wqi->submit_element_info = ring_tail << WQ_RING_TAIL_SHIFT;
454 	wqi->fence_id = rq->global_seqno;
455 
456 	/* Postincrement WQ tail for next time. */
457 	WRITE_ONCE(desc->tail, (wq_off + wqi_size) & (GUC_WQ_SIZE - 1));
458 }
459 
460 static void guc_reset_wq(struct i915_guc_client *client)
461 {
462 	struct guc_process_desc *desc = __get_process_desc(client);
463 
464 	desc->head = 0;
465 	desc->tail = 0;
466 }
467 
468 static void guc_ring_doorbell(struct i915_guc_client *client)
469 {
470 	struct guc_doorbell_info *db;
471 	u32 cookie;
472 
473 	lockdep_assert_held(&client->wq_lock);
474 
475 	/* pointer of current doorbell cacheline */
476 	db = __get_doorbell(client);
477 
478 	/* we're not expecting the doorbell cookie to change behind our back */
479 	cookie = READ_ONCE(db->cookie);
480 	WARN_ON_ONCE(xchg(&db->cookie, cookie + 1) != cookie);
481 
482 	/* XXX: doorbell was lost and need to acquire it again */
483 	GEM_BUG_ON(db->db_status != GUC_DOORBELL_ENABLED);
484 }
485 
486 /**
487  * i915_guc_submit() - Submit commands through GuC
488  * @engine: engine associated with the commands
489  *
490  * The only error here arises if the doorbell hardware isn't functioning
491  * as expected, which really shouln't happen.
492  */
493 static void i915_guc_submit(struct intel_engine_cs *engine)
494 {
495 	struct drm_i915_private *dev_priv = engine->i915;
496 	struct intel_guc *guc = &dev_priv->guc;
497 	struct i915_guc_client *client = guc->execbuf_client;
498 	struct intel_engine_execlists * const execlists = &engine->execlists;
499 	struct execlist_port *port = execlists->port;
500 	const unsigned int engine_id = engine->id;
501 	unsigned int n;
502 
503 	for (n = 0; n < execlists_num_ports(execlists); n++) {
504 		struct drm_i915_gem_request *rq;
505 		unsigned int count;
506 
507 		rq = port_unpack(&port[n], &count);
508 		if (rq && count == 0) {
509 			port_set(&port[n], port_pack(rq, ++count));
510 
511 			if (i915_vma_is_map_and_fenceable(rq->ring->vma))
512 				POSTING_READ_FW(GUC_STATUS);
513 
514 			lockmgr(&client->wq_lock, LK_EXCLUSIVE);
515 
516 			guc_wq_item_append(client, rq);
517 			guc_ring_doorbell(client);
518 
519 			client->submissions[engine_id] += 1;
520 
521 			lockmgr(&client->wq_lock, LK_RELEASE);
522 		}
523 	}
524 }
525 
526 static void nested_enable_signaling(struct drm_i915_gem_request *rq)
527 {
528 	/* If we use dma_fence_enable_sw_signaling() directly, lockdep
529 	 * detects an ordering issue between the fence lockclass and the
530 	 * global_timeline. This circular dependency can only occur via 2
531 	 * different fences (but same fence lockclass), so we use the nesting
532 	 * annotation here to prevent the warn, equivalent to the nesting
533 	 * inside i915_gem_request_submit() for when we also enable the
534 	 * signaler.
535 	 */
536 
537 	if (test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
538 			     &rq->fence.flags))
539 		return;
540 
541 	GEM_BUG_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags));
542 	trace_dma_fence_enable_signal(&rq->fence);
543 
544 	lockmgr(&rq->lock, LK_EXCLUSIVE);
545 	intel_engine_enable_signaling(rq, true);
546 	lockmgr(&rq->lock, LK_RELEASE);
547 }
548 
549 static void port_assign(struct execlist_port *port,
550 			struct drm_i915_gem_request *rq)
551 {
552 	GEM_BUG_ON(rq == port_request(port));
553 
554 	if (port_isset(port))
555 		i915_gem_request_put(port_request(port));
556 
557 	port_set(port, port_pack(i915_gem_request_get(rq), port_count(port)));
558 	nested_enable_signaling(rq);
559 }
560 
561 static void i915_guc_dequeue(struct intel_engine_cs *engine)
562 {
563 	struct intel_engine_execlists * const execlists = &engine->execlists;
564 	struct execlist_port *port = execlists->port;
565 	struct drm_i915_gem_request *last = NULL;
566 	const struct execlist_port * const last_port =
567 		&execlists->port[execlists->port_mask];
568 	bool submit = false;
569 	struct rb_node *rb;
570 
571 	if (port_isset(port))
572 		port++;
573 
574 	spin_lock_irq(&engine->timeline->lock);
575 	rb = execlists->first;
576 	GEM_BUG_ON(rb_first(&execlists->queue) != rb);
577 	while (rb) {
578 		struct i915_priolist *p = rb_entry(rb, typeof(*p), node);
579 		struct drm_i915_gem_request *rq, *rn;
580 
581 		list_for_each_entry_safe(rq, rn, &p->requests, priotree.link) {
582 			if (last && rq->ctx != last->ctx) {
583 				if (port == last_port) {
584 					__list_del_many(&p->requests,
585 							&rq->priotree.link);
586 					goto done;
587 				}
588 
589 				if (submit)
590 					port_assign(port, last);
591 				port++;
592 			}
593 
594 			INIT_LIST_HEAD(&rq->priotree.link);
595 			rq->priotree.priority = INT_MAX;
596 
597 			__i915_gem_request_submit(rq);
598 			trace_i915_gem_request_in(rq, port_index(port, execlists));
599 			last = rq;
600 			submit = true;
601 		}
602 
603 		rb = rb_next(rb);
604 		rb_erase(&p->node, &execlists->queue);
605 		INIT_LIST_HEAD(&p->requests);
606 		if (p->priority != I915_PRIORITY_NORMAL)
607 			kmem_cache_free(engine->i915->priorities, p);
608 	}
609 done:
610 	execlists->first = rb;
611 	if (submit) {
612 		port_assign(port, last);
613 		execlists_set_active(execlists, EXECLISTS_ACTIVE_USER);
614 		i915_guc_submit(engine);
615 	}
616 	spin_unlock_irq(&engine->timeline->lock);
617 }
618 
619 static void i915_guc_irq_handler(unsigned long data)
620 {
621 	struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
622 	struct intel_engine_execlists * const execlists = &engine->execlists;
623 	struct execlist_port *port = execlists->port;
624 	const struct execlist_port * const last_port =
625 		&execlists->port[execlists->port_mask];
626 	struct drm_i915_gem_request *rq;
627 
628 	rq = port_request(&port[0]);
629 	while (rq && i915_gem_request_completed(rq)) {
630 		trace_i915_gem_request_out(rq);
631 		i915_gem_request_put(rq);
632 
633 		execlists_port_complete(execlists, port);
634 
635 		rq = port_request(&port[0]);
636 	}
637 	if (!rq)
638 		execlists_clear_active(execlists, EXECLISTS_ACTIVE_USER);
639 
640 	if (!port_isset(last_port))
641 		i915_guc_dequeue(engine);
642 }
643 
644 /*
645  * Everything below here is concerned with setup & teardown, and is
646  * therefore not part of the somewhat time-critical batch-submission
647  * path of i915_guc_submit() above.
648  */
649 
650 /* Check that a doorbell register is in the expected state */
651 static bool doorbell_ok(struct intel_guc *guc, u16 db_id)
652 {
653 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
654 	u32 drbregl;
655 	bool valid;
656 
657 	GEM_BUG_ON(db_id >= GUC_DOORBELL_INVALID);
658 
659 	drbregl = I915_READ(GEN8_DRBREGL(db_id));
660 	valid = drbregl & GEN8_DRB_VALID;
661 
662 	if (test_bit(db_id, guc->doorbell_bitmap) == valid)
663 		return true;
664 
665 	DRM_DEBUG_DRIVER("Doorbell %d has unexpected state (0x%x): valid=%s\n",
666 			 db_id, drbregl, yesno(valid));
667 
668 	return false;
669 }
670 
671 /*
672  * If the GuC thinks that the doorbell is unassigned (e.g. because we reset and
673  * reloaded the GuC FW) we can use this function to tell the GuC to reassign the
674  * doorbell to the rightful owner.
675  */
676 static int __reset_doorbell(struct i915_guc_client* client, u16 db_id)
677 {
678 	int err;
679 
680 	__update_doorbell_desc(client, db_id);
681 	err = __create_doorbell(client);
682 	if (!err)
683 		err = __destroy_doorbell(client);
684 
685 	return err;
686 }
687 
688 /*
689  * Set up & tear down each unused doorbell in turn, to ensure that all doorbell
690  * HW is (re)initialised. For that end, we might have to borrow the first
691  * client. Also, tell GuC about all the doorbells in use by all clients.
692  * We do this because the KMD, the GuC and the doorbell HW can easily go out of
693  * sync (e.g. we can reset the GuC, but not the doorbel HW).
694  */
695 static int guc_init_doorbell_hw(struct intel_guc *guc)
696 {
697 	struct i915_guc_client *client = guc->execbuf_client;
698 	bool recreate_first_client = false;
699 	u16 db_id;
700 	int ret;
701 
702 	/* For unused doorbells, make sure they are disabled */
703 	for_each_clear_bit(db_id, guc->doorbell_bitmap, GUC_NUM_DOORBELLS) {
704 		if (doorbell_ok(guc, db_id))
705 			continue;
706 
707 		if (has_doorbell(client)) {
708 			/* Borrow execbuf_client (we will recreate it later) */
709 			destroy_doorbell(client);
710 			recreate_first_client = true;
711 		}
712 
713 		ret = __reset_doorbell(client, db_id);
714 		WARN(ret, "Doorbell %u reset failed, err %d\n", db_id, ret);
715 	}
716 
717 	if (recreate_first_client) {
718 		ret = __reserve_doorbell(client);
719 		if (unlikely(ret)) {
720 			DRM_ERROR("Couldn't re-reserve first client db: %d\n", ret);
721 			return ret;
722 		}
723 
724 		__update_doorbell_desc(client, client->doorbell_id);
725 	}
726 
727 	/* Now for every client (and not only execbuf_client) make sure their
728 	 * doorbells are known by the GuC */
729 	//for (client = client_list; client != NULL; client = client->next)
730 	{
731 		ret = __create_doorbell(client);
732 		if (ret) {
733 			DRM_ERROR("Couldn't recreate client %u doorbell: %d\n",
734 				client->stage_id, ret);
735 			return ret;
736 		}
737 	}
738 
739 	/* Read back & verify all (used & unused) doorbell registers */
740 	for (db_id = 0; db_id < GUC_NUM_DOORBELLS; ++db_id)
741 		WARN_ON(!doorbell_ok(guc, db_id));
742 
743 	return 0;
744 }
745 
746 /**
747  * guc_client_alloc() - Allocate an i915_guc_client
748  * @dev_priv:	driver private data structure
749  * @engines:	The set of engines to enable for this client
750  * @priority:	four levels priority _CRITICAL, _HIGH, _NORMAL and _LOW
751  * 		The kernel client to replace ExecList submission is created with
752  * 		NORMAL priority. Priority of a client for scheduler can be HIGH,
753  * 		while a preemption context can use CRITICAL.
754  * @ctx:	the context that owns the client (we use the default render
755  * 		context)
756  *
757  * Return:	An i915_guc_client object if success, else NULL.
758  */
759 static struct i915_guc_client *
760 guc_client_alloc(struct drm_i915_private *dev_priv,
761 		 u32 engines,
762 		 u32 priority,
763 		 struct i915_gem_context *ctx)
764 {
765 	struct i915_guc_client *client;
766 	struct intel_guc *guc = &dev_priv->guc;
767 	struct i915_vma *vma;
768 	void *vaddr;
769 	int ret;
770 
771 	client = kzalloc(sizeof(*client), GFP_KERNEL);
772 	if (!client)
773 		return ERR_PTR(-ENOMEM);
774 
775 	client->guc = guc;
776 	client->owner = ctx;
777 	client->engines = engines;
778 	client->priority = priority;
779 	client->doorbell_id = GUC_DOORBELL_INVALID;
780 	lockinit(&client->wq_lock, "i9gcwql", 0, 0);
781 
782 	ret = ida_simple_get(&guc->stage_ids, 0, GUC_MAX_STAGE_DESCRIPTORS,
783 				GFP_KERNEL);
784 	if (ret < 0)
785 		goto err_client;
786 
787 	client->stage_id = ret;
788 
789 	/* The first page is doorbell/proc_desc. Two followed pages are wq. */
790 	vma = intel_guc_allocate_vma(guc, GUC_DB_SIZE + GUC_WQ_SIZE);
791 	if (IS_ERR(vma)) {
792 		ret = PTR_ERR(vma);
793 		goto err_id;
794 	}
795 
796 	/* We'll keep just the first (doorbell/proc) page permanently kmap'd. */
797 	client->vma = vma;
798 
799 	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
800 	if (IS_ERR(vaddr)) {
801 		ret = PTR_ERR(vaddr);
802 		goto err_vma;
803 	}
804 	client->vaddr = vaddr;
805 
806 	client->doorbell_offset = __select_cacheline(guc);
807 
808 	/*
809 	 * Since the doorbell only requires a single cacheline, we can save
810 	 * space by putting the application process descriptor in the same
811 	 * page. Use the half of the page that doesn't include the doorbell.
812 	 */
813 	if (client->doorbell_offset >= (GUC_DB_SIZE / 2))
814 		client->proc_desc_offset = 0;
815 	else
816 		client->proc_desc_offset = (GUC_DB_SIZE / 2);
817 
818 	guc_proc_desc_init(guc, client);
819 	guc_stage_desc_init(guc, client);
820 
821 	ret = create_doorbell(client);
822 	if (ret)
823 		goto err_vaddr;
824 
825 	DRM_DEBUG_DRIVER("new priority %u client %p for engine(s) 0x%x: stage_id %u\n",
826 			 priority, client, client->engines, client->stage_id);
827 	DRM_DEBUG_DRIVER("doorbell id %u, cacheline offset 0x%lx\n",
828 			 client->doorbell_id, client->doorbell_offset);
829 
830 	return client;
831 
832 err_vaddr:
833 	i915_gem_object_unpin_map(client->vma->obj);
834 err_vma:
835 	i915_vma_unpin_and_release(&client->vma);
836 err_id:
837 	ida_simple_remove(&guc->stage_ids, client->stage_id);
838 err_client:
839 	kfree(client);
840 	return ERR_PTR(ret);
841 }
842 
843 static void guc_client_free(struct i915_guc_client *client)
844 {
845 	/*
846 	 * XXX: wait for any outstanding submissions before freeing memory.
847 	 * Be sure to drop any locks
848 	 */
849 
850 	/* FIXME: in many cases, by the time we get here the GuC has been
851 	 * reset, so we cannot destroy the doorbell properly. Ignore the
852 	 * error message for now */
853 	destroy_doorbell(client);
854 	guc_stage_desc_fini(client->guc, client);
855 	i915_gem_object_unpin_map(client->vma->obj);
856 	i915_vma_unpin_and_release(&client->vma);
857 	ida_simple_remove(&client->guc->stage_ids, client->stage_id);
858 	kfree(client);
859 }
860 
861 static void guc_policy_init(struct guc_policy *policy)
862 {
863 	policy->execution_quantum = POLICY_DEFAULT_EXECUTION_QUANTUM_US;
864 	policy->preemption_time = POLICY_DEFAULT_PREEMPTION_TIME_US;
865 	policy->fault_time = POLICY_DEFAULT_FAULT_TIME_US;
866 	policy->policy_flags = 0;
867 }
868 
869 static void guc_policies_init(struct guc_policies *policies)
870 {
871 	struct guc_policy *policy;
872 	u32 p, i;
873 
874 	policies->dpc_promote_time = POLICY_DEFAULT_DPC_PROMOTE_TIME_US;
875 	policies->max_num_work_items = POLICY_MAX_NUM_WI;
876 
877 	for (p = 0; p < GUC_CLIENT_PRIORITY_NUM; p++) {
878 		for (i = GUC_RENDER_ENGINE; i < GUC_MAX_ENGINES_NUM; i++) {
879 			policy = &policies->policy[p][i];
880 
881 			guc_policy_init(policy);
882 		}
883 	}
884 
885 	policies->is_valid = 1;
886 }
887 
888 /*
889  * The first 80 dwords of the register state context, containing the
890  * execlists and ppgtt registers.
891  */
892 #define LR_HW_CONTEXT_SIZE	(80 * sizeof(u32))
893 
894 static int guc_ads_create(struct intel_guc *guc)
895 {
896 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
897 	struct i915_vma *vma;
898 	struct page *page;
899 	/* The ads obj includes the struct itself and buffers passed to GuC */
900 	struct {
901 		struct guc_ads ads;
902 		struct guc_policies policies;
903 		struct guc_mmio_reg_state reg_state;
904 		u8 reg_state_buffer[GUC_S3_SAVE_SPACE_PAGES * PAGE_SIZE];
905 	} __packed *blob;
906 	struct intel_engine_cs *engine;
907 	enum intel_engine_id id;
908 	const u32 skipped_offset = LRC_HEADER_PAGES * PAGE_SIZE;
909 	const u32 skipped_size = LRC_PPHWSP_SZ * PAGE_SIZE + LR_HW_CONTEXT_SIZE;
910 	u32 base;
911 
912 	GEM_BUG_ON(guc->ads_vma);
913 
914 	vma = intel_guc_allocate_vma(guc, PAGE_ALIGN(sizeof(*blob)));
915 	if (IS_ERR(vma))
916 		return PTR_ERR(vma);
917 
918 	guc->ads_vma = vma;
919 
920 	page = i915_vma_first_page(vma);
921 	blob = kmap(page);
922 
923 	/* GuC scheduling policies */
924 	guc_policies_init(&blob->policies);
925 
926 	/* MMIO reg state */
927 	for_each_engine(engine, dev_priv, id) {
928 		blob->reg_state.white_list[engine->guc_id].mmio_start =
929 			engine->mmio_base + GUC_MMIO_WHITE_LIST_START;
930 
931 		/* Nothing to be saved or restored for now. */
932 		blob->reg_state.white_list[engine->guc_id].count = 0;
933 	}
934 
935 	/*
936 	 * The GuC requires a "Golden Context" when it reinitialises
937 	 * engines after a reset. Here we use the Render ring default
938 	 * context, which must already exist and be pinned in the GGTT,
939 	 * so its address won't change after we've told the GuC where
940 	 * to find it. Note that we have to skip our header (1 page),
941 	 * because our GuC shared data is there.
942 	 */
943 	blob->ads.golden_context_lrca =
944 		guc_ggtt_offset(dev_priv->kernel_context->engine[RCS].state) + skipped_offset;
945 
946 	/*
947 	 * The GuC expects us to exclude the portion of the context image that
948 	 * it skips from the size it is to read. It starts reading from after
949 	 * the execlist context (so skipping the first page [PPHWSP] and 80
950 	 * dwords). Weird guc is weird.
951 	 */
952 	for_each_engine(engine, dev_priv, id)
953 		blob->ads.eng_state_size[engine->guc_id] = engine->context_size - skipped_size;
954 
955 	base = guc_ggtt_offset(vma);
956 	blob->ads.scheduler_policies = base + ptr_offset(blob, policies);
957 	blob->ads.reg_state_buffer = base + ptr_offset(blob, reg_state_buffer);
958 	blob->ads.reg_state_addr = base + ptr_offset(blob, reg_state);
959 
960 	kunmap(page);
961 
962 	return 0;
963 }
964 
965 static void guc_ads_destroy(struct intel_guc *guc)
966 {
967 	i915_vma_unpin_and_release(&guc->ads_vma);
968 }
969 
970 /*
971  * Set up the memory resources to be shared with the GuC (via the GGTT)
972  * at firmware loading time.
973  */
974 int i915_guc_submission_init(struct drm_i915_private *dev_priv)
975 {
976 	struct intel_guc *guc = &dev_priv->guc;
977 	struct i915_vma *vma;
978 	void *vaddr;
979 	int ret;
980 
981 	if (guc->stage_desc_pool)
982 		return 0;
983 
984 	vma = intel_guc_allocate_vma(guc,
985 				PAGE_ALIGN(sizeof(struct guc_stage_desc) *
986 					GUC_MAX_STAGE_DESCRIPTORS));
987 	if (IS_ERR(vma))
988 		return PTR_ERR(vma);
989 
990 	guc->stage_desc_pool = vma;
991 
992 	vaddr = i915_gem_object_pin_map(guc->stage_desc_pool->obj, I915_MAP_WB);
993 	if (IS_ERR(vaddr)) {
994 		ret = PTR_ERR(vaddr);
995 		goto err_vma;
996 	}
997 
998 	guc->stage_desc_pool_vaddr = vaddr;
999 
1000 	ret = intel_guc_log_create(guc);
1001 	if (ret < 0)
1002 		goto err_vaddr;
1003 
1004 	ret = guc_ads_create(guc);
1005 	if (ret < 0)
1006 		goto err_log;
1007 
1008 	ida_init(&guc->stage_ids);
1009 
1010 	return 0;
1011 
1012 err_log:
1013 	intel_guc_log_destroy(guc);
1014 err_vaddr:
1015 	i915_gem_object_unpin_map(guc->stage_desc_pool->obj);
1016 err_vma:
1017 	i915_vma_unpin_and_release(&guc->stage_desc_pool);
1018 	return ret;
1019 }
1020 
1021 void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
1022 {
1023 	struct intel_guc *guc = &dev_priv->guc;
1024 
1025 	ida_destroy(&guc->stage_ids);
1026 	guc_ads_destroy(guc);
1027 	intel_guc_log_destroy(guc);
1028 	i915_gem_object_unpin_map(guc->stage_desc_pool->obj);
1029 	i915_vma_unpin_and_release(&guc->stage_desc_pool);
1030 }
1031 
1032 static void guc_interrupts_capture(struct drm_i915_private *dev_priv)
1033 {
1034 	struct intel_rps *rps = &dev_priv->gt_pm.rps;
1035 	struct intel_engine_cs *engine;
1036 	enum intel_engine_id id;
1037 	int irqs;
1038 
1039 	/* tell all command streamers to forward interrupts (but not vblank) to GuC */
1040 	irqs = _MASKED_BIT_ENABLE(GFX_INTERRUPT_STEERING);
1041 	for_each_engine(engine, dev_priv, id)
1042 		I915_WRITE(RING_MODE_GEN7(engine), irqs);
1043 
1044 	/* route USER_INTERRUPT to Host, all others are sent to GuC. */
1045 	irqs = GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
1046 	       GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
1047 	/* These three registers have the same bit definitions */
1048 	I915_WRITE(GUC_BCS_RCS_IER, ~irqs);
1049 	I915_WRITE(GUC_VCS2_VCS1_IER, ~irqs);
1050 	I915_WRITE(GUC_WD_VECS_IER, ~irqs);
1051 
1052 	/*
1053 	 * The REDIRECT_TO_GUC bit of the PMINTRMSK register directs all
1054 	 * (unmasked) PM interrupts to the GuC. All other bits of this
1055 	 * register *disable* generation of a specific interrupt.
1056 	 *
1057 	 * 'pm_intrmsk_mbz' indicates bits that are NOT to be set when
1058 	 * writing to the PM interrupt mask register, i.e. interrupts
1059 	 * that must not be disabled.
1060 	 *
1061 	 * If the GuC is handling these interrupts, then we must not let
1062 	 * the PM code disable ANY interrupt that the GuC is expecting.
1063 	 * So for each ENABLED (0) bit in this register, we must SET the
1064 	 * bit in pm_intrmsk_mbz so that it's left enabled for the GuC.
1065 	 * GuC needs ARAT expired interrupt unmasked hence it is set in
1066 	 * pm_intrmsk_mbz.
1067 	 *
1068 	 * Here we CLEAR REDIRECT_TO_GUC bit in pm_intrmsk_mbz, which will
1069 	 * result in the register bit being left SET!
1070 	 */
1071 	rps->pm_intrmsk_mbz |= ARAT_EXPIRED_INTRMSK;
1072 	rps->pm_intrmsk_mbz &= ~GEN8_PMINTR_DISABLE_REDIRECT_TO_GUC;
1073 }
1074 
1075 static void guc_interrupts_release(struct drm_i915_private *dev_priv)
1076 {
1077 	struct intel_rps *rps = &dev_priv->gt_pm.rps;
1078 	struct intel_engine_cs *engine;
1079 	enum intel_engine_id id;
1080 	int irqs;
1081 
1082 	/*
1083 	 * tell all command streamers NOT to forward interrupts or vblank
1084 	 * to GuC.
1085 	 */
1086 	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_NEVER);
1087 	irqs |= _MASKED_BIT_DISABLE(GFX_INTERRUPT_STEERING);
1088 	for_each_engine(engine, dev_priv, id)
1089 		I915_WRITE(RING_MODE_GEN7(engine), irqs);
1090 
1091 	/* route all GT interrupts to the host */
1092 	I915_WRITE(GUC_BCS_RCS_IER, 0);
1093 	I915_WRITE(GUC_VCS2_VCS1_IER, 0);
1094 	I915_WRITE(GUC_WD_VECS_IER, 0);
1095 
1096 	rps->pm_intrmsk_mbz |= GEN8_PMINTR_DISABLE_REDIRECT_TO_GUC;
1097 	rps->pm_intrmsk_mbz &= ~ARAT_EXPIRED_INTRMSK;
1098 }
1099 
1100 int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
1101 {
1102 	struct intel_guc *guc = &dev_priv->guc;
1103 	struct i915_guc_client *client = guc->execbuf_client;
1104 	struct intel_engine_cs *engine;
1105 	enum intel_engine_id id;
1106 	int err;
1107 
1108 	/*
1109 	 * We're using GuC work items for submitting work through GuC. Since
1110 	 * we're coalescing multiple requests from a single context into a
1111 	 * single work item prior to assigning it to execlist_port, we can
1112 	 * never have more work items than the total number of ports (for all
1113 	 * engines). The GuC firmware is controlling the HEAD of work queue,
1114 	 * and it is guaranteed that it will remove the work item from the
1115 	 * queue before our request is completed.
1116 	 */
1117 	BUILD_BUG_ON(ARRAY_SIZE(engine->execlists.port) *
1118 		     sizeof(struct guc_wq_item) *
1119 		     I915_NUM_ENGINES > GUC_WQ_SIZE);
1120 
1121 	if (!client) {
1122 		client = guc_client_alloc(dev_priv,
1123 					  INTEL_INFO(dev_priv)->ring_mask,
1124 					  GUC_CLIENT_PRIORITY_KMD_NORMAL,
1125 					  dev_priv->kernel_context);
1126 		if (IS_ERR(client)) {
1127 			DRM_ERROR("Failed to create GuC client for execbuf!\n");
1128 			return PTR_ERR(client);
1129 		}
1130 
1131 		guc->execbuf_client = client;
1132 	}
1133 
1134 	err = intel_guc_sample_forcewake(guc);
1135 	if (err)
1136 		goto err_execbuf_client;
1137 
1138 	guc_reset_wq(client);
1139 
1140 	err = guc_init_doorbell_hw(guc);
1141 	if (err)
1142 		goto err_execbuf_client;
1143 
1144 	/* Take over from manual control of ELSP (execlists) */
1145 	guc_interrupts_capture(dev_priv);
1146 
1147 	for_each_engine(engine, dev_priv, id) {
1148 		struct intel_engine_execlists * const execlists = &engine->execlists;
1149 		/* The tasklet was initialised by execlists, and may be in
1150 		 * a state of flux (across a reset) and so we just want to
1151 		 * take over the callback without changing any other state
1152 		 * in the tasklet.
1153 		 */
1154 		execlists->irq_tasklet.func = i915_guc_irq_handler;
1155 		clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted);
1156 		tasklet_schedule(&execlists->irq_tasklet);
1157 	}
1158 
1159 	return 0;
1160 
1161 err_execbuf_client:
1162 	guc_client_free(guc->execbuf_client);
1163 	guc->execbuf_client = NULL;
1164 	return err;
1165 }
1166 
1167 void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
1168 {
1169 	struct intel_guc *guc = &dev_priv->guc;
1170 
1171 	guc_interrupts_release(dev_priv);
1172 
1173 	/* Revert back to manual ELSP submission */
1174 	intel_engines_reset_default_submission(dev_priv);
1175 
1176 	guc_client_free(guc->execbuf_client);
1177 	guc->execbuf_client = NULL;
1178 }
1179