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1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2019 Intel Corporation
4 */
5
6#include "gem/i915_gem_context.h"
7#include "gem/i915_gem_pm.h"
8
9#include "i915_drm_client.h"
10#include "i915_drv.h"
11#include "i915_trace.h"
12
13#include "intel_context.h"
14#include "intel_engine.h"
15#include "intel_engine_pm.h"
16#include "intel_ring.h"
17
18static struct kmem_cache *slab_ce;
19
20static struct intel_context *intel_context_alloc(void)
21{
22 return kmem_cache_zalloc(slab_ce, GFP_KERNEL);
23}
24
25static void rcu_context_free(struct rcu_head *rcu)
26{
27 struct intel_context *ce = container_of(rcu, typeof(*ce), rcu);
28
29 trace_intel_context_free(ce);
30 if (intel_context_has_own_state(ce))
31 fput(ce->default_state);
32 kmem_cache_free(slab_ce, ce);
33}
34
35void intel_context_free(struct intel_context *ce)
36{
37 call_rcu(&ce->rcu, rcu_context_free);
38}
39
40struct intel_context *
41intel_context_create(struct intel_engine_cs *engine)
42{
43 struct intel_context *ce;
44
45 ce = intel_context_alloc();
46 if (!ce)
47 return ERR_PTR(-ENOMEM);
48
49 intel_context_init(ce, engine);
50 trace_intel_context_create(ce);
51 return ce;
52}
53
54int intel_context_alloc_state(struct intel_context *ce)
55{
56 struct i915_gem_context *ctx;
57 int err = 0;
58
59 if (mutex_lock_interruptible(&ce->pin_mutex))
60 return -EINTR;
61
62 if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
63 if (intel_context_is_banned(ce)) {
64 err = -EIO;
65 goto unlock;
66 }
67
68 err = ce->ops->alloc(ce);
69 if (unlikely(err))
70 goto unlock;
71
72 set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
73
74 rcu_read_lock();
75 ctx = rcu_dereference(ce->gem_context);
76 if (ctx && !kref_get_unless_zero(&ctx->ref))
77 ctx = NULL;
78 rcu_read_unlock();
79 if (ctx) {
80 if (ctx->client)
81 i915_drm_client_add_context_objects(ctx->client,
82 ce);
83 i915_gem_context_put(ctx);
84 }
85 }
86
87unlock:
88 mutex_unlock(&ce->pin_mutex);
89 return err;
90}
91
92static int intel_context_active_acquire(struct intel_context *ce)
93{
94 int err;
95
96 __i915_active_acquire(&ce->active);
97
98 if (intel_context_is_barrier(ce) || intel_engine_uses_guc(ce->engine) ||
99 intel_context_is_parallel(ce))
100 return 0;
101
102 /* Preallocate tracking nodes */
103 err = i915_active_acquire_preallocate_barrier(&ce->active,
104 ce->engine);
105 if (err)
106 i915_active_release(&ce->active);
107
108 return err;
109}
110
111static void intel_context_active_release(struct intel_context *ce)
112{
113 /* Nodes preallocated in intel_context_active() */
114 i915_active_acquire_barrier(&ce->active);
115 i915_active_release(&ce->active);
116}
117
118static int __context_pin_state(struct i915_vma *vma, struct i915_gem_ww_ctx *ww)
119{
120 unsigned int bias = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;
121 int err;
122
123 err = i915_ggtt_pin(vma, ww, 0, bias | PIN_HIGH);
124 if (err)
125 return err;
126
127 err = i915_active_acquire(&vma->active);
128 if (err)
129 goto err_unpin;
130
131 /*
132 * And mark it as a globally pinned object to let the shrinker know
133 * it cannot reclaim the object until we release it.
134 */
135 i915_vma_make_unshrinkable(vma);
136 vma->obj->mm.dirty = true;
137
138 return 0;
139
140err_unpin:
141 i915_vma_unpin(vma);
142 return err;
143}
144
145static void __context_unpin_state(struct i915_vma *vma)
146{
147 i915_vma_make_shrinkable(vma);
148 i915_active_release(&vma->active);
149 __i915_vma_unpin(vma);
150}
151
152static int __ring_active(struct intel_ring *ring,
153 struct i915_gem_ww_ctx *ww)
154{
155 int err;
156
157 err = intel_ring_pin(ring, ww);
158 if (err)
159 return err;
160
161 err = i915_active_acquire(&ring->vma->active);
162 if (err)
163 goto err_pin;
164
165 return 0;
166
167err_pin:
168 intel_ring_unpin(ring);
169 return err;
170}
171
172static void __ring_retire(struct intel_ring *ring)
173{
174 i915_active_release(&ring->vma->active);
175 intel_ring_unpin(ring);
176}
177
178static int intel_context_pre_pin(struct intel_context *ce,
179 struct i915_gem_ww_ctx *ww)
180{
181 int err;
182
183 CE_TRACE(ce, "active\n");
184
185 err = __ring_active(ce->ring, ww);
186 if (err)
187 return err;
188
189 err = intel_timeline_pin(ce->timeline, ww);
190 if (err)
191 goto err_ring;
192
193 if (!ce->state)
194 return 0;
195
196 err = __context_pin_state(ce->state, ww);
197 if (err)
198 goto err_timeline;
199
200
201 return 0;
202
203err_timeline:
204 intel_timeline_unpin(ce->timeline);
205err_ring:
206 __ring_retire(ce->ring);
207 return err;
208}
209
210static void intel_context_post_unpin(struct intel_context *ce)
211{
212 if (ce->state)
213 __context_unpin_state(ce->state);
214
215 intel_timeline_unpin(ce->timeline);
216 __ring_retire(ce->ring);
217}
218
219int __intel_context_do_pin_ww(struct intel_context *ce,
220 struct i915_gem_ww_ctx *ww)
221{
222 bool handoff = false;
223 void *vaddr;
224 int err = 0;
225
226 if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
227 err = intel_context_alloc_state(ce);
228 if (err)
229 return err;
230 }
231
232 /*
233 * We always pin the context/ring/timeline here, to ensure a pin
234 * refcount for __intel_context_active(), which prevent a lock
235 * inversion of ce->pin_mutex vs dma_resv_lock().
236 */
237
238 err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, ww);
239 if (!err)
240 err = i915_gem_object_lock(ce->ring->vma->obj, ww);
241 if (!err && ce->state)
242 err = i915_gem_object_lock(ce->state->obj, ww);
243 if (!err)
244 err = intel_context_pre_pin(ce, ww);
245 if (err)
246 return err;
247
248 err = ce->ops->pre_pin(ce, ww, &vaddr);
249 if (err)
250 goto err_ctx_unpin;
251
252 err = i915_active_acquire(&ce->active);
253 if (err)
254 goto err_post_unpin;
255
256 err = mutex_lock_interruptible(&ce->pin_mutex);
257 if (err)
258 goto err_release;
259
260 intel_engine_pm_might_get(ce->engine);
261
262 if (unlikely(intel_context_is_closed(ce))) {
263 err = -ENOENT;
264 goto err_unlock;
265 }
266
267 if (likely(!atomic_add_unless(&ce->pin_count, 1, 0))) {
268 err = intel_context_active_acquire(ce);
269 if (unlikely(err))
270 goto err_unlock;
271
272 err = ce->ops->pin(ce, vaddr);
273 if (err) {
274 intel_context_active_release(ce);
275 goto err_unlock;
276 }
277
278 CE_TRACE(ce, "pin ring:{start:%08x, head:%04x, tail:%04x}\n",
279 i915_ggtt_offset(ce->ring->vma),
280 ce->ring->head, ce->ring->tail);
281
282 handoff = true;
283 smp_mb__before_atomic(); /* flush pin before it is visible */
284 atomic_inc(&ce->pin_count);
285 }
286
287 GEM_BUG_ON(!intel_context_is_pinned(ce)); /* no overflow! */
288
289 trace_intel_context_do_pin(ce);
290
291err_unlock:
292 mutex_unlock(&ce->pin_mutex);
293err_release:
294 i915_active_release(&ce->active);
295err_post_unpin:
296 if (!handoff)
297 ce->ops->post_unpin(ce);
298err_ctx_unpin:
299 intel_context_post_unpin(ce);
300
301 /*
302 * Unlock the hwsp_ggtt object since it's shared.
303 * In principle we can unlock all the global state locked above
304 * since it's pinned and doesn't need fencing, and will
305 * thus remain resident until it is explicitly unpinned.
306 */
307 i915_gem_ww_unlock_single(ce->timeline->hwsp_ggtt->obj);
308
309 return err;
310}
311
312int __intel_context_do_pin(struct intel_context *ce)
313{
314 struct i915_gem_ww_ctx ww;
315 int err;
316
317 i915_gem_ww_ctx_init(&ww, true);
318retry:
319 err = __intel_context_do_pin_ww(ce, &ww);
320 if (err == -EDEADLK) {
321 err = i915_gem_ww_ctx_backoff(&ww);
322 if (!err)
323 goto retry;
324 }
325 i915_gem_ww_ctx_fini(&ww);
326 return err;
327}
328
329void __intel_context_do_unpin(struct intel_context *ce, int sub)
330{
331 if (!atomic_sub_and_test(sub, &ce->pin_count))
332 return;
333
334 CE_TRACE(ce, "unpin\n");
335 ce->ops->unpin(ce);
336 ce->ops->post_unpin(ce);
337
338 /*
339 * Once released, we may asynchronously drop the active reference.
340 * As that may be the only reference keeping the context alive,
341 * take an extra now so that it is not freed before we finish
342 * dereferencing it.
343 */
344 intel_context_get(ce);
345 intel_context_active_release(ce);
346 trace_intel_context_do_unpin(ce);
347 intel_context_put(ce);
348}
349
350static void __intel_context_retire(struct i915_active *active)
351{
352 struct intel_context *ce = container_of(active, typeof(*ce), active);
353
354 CE_TRACE(ce, "retire runtime: { total:%lluns, avg:%lluns }\n",
355 intel_context_get_total_runtime_ns(ce),
356 intel_context_get_avg_runtime_ns(ce));
357
358 set_bit(CONTEXT_VALID_BIT, &ce->flags);
359 intel_context_post_unpin(ce);
360 intel_context_put(ce);
361}
362
363static int __intel_context_active(struct i915_active *active)
364{
365 struct intel_context *ce = container_of(active, typeof(*ce), active);
366
367 intel_context_get(ce);
368
369 /* everything should already be activated by intel_context_pre_pin() */
370 GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->ring->vma->active));
371 __intel_ring_pin(ce->ring);
372
373 __intel_timeline_pin(ce->timeline);
374
375 if (ce->state) {
376 GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->state->active));
377 __i915_vma_pin(ce->state);
378 i915_vma_make_unshrinkable(ce->state);
379 }
380
381 return 0;
382}
383
384static int
385sw_fence_dummy_notify(struct i915_sw_fence *sf,
386 enum i915_sw_fence_notify state)
387{
388 return NOTIFY_DONE;
389}
390
391void
392intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
393{
394 GEM_BUG_ON(!engine->cops);
395 GEM_BUG_ON(!engine->gt->vm);
396
397 kref_init(&ce->ref);
398
399 ce->engine = engine;
400 ce->ops = engine->cops;
401 ce->sseu = engine->sseu;
402 ce->ring = NULL;
403 ce->ring_size = SZ_4K;
404
405 ewma_runtime_init(&ce->stats.runtime.avg);
406
407 ce->vm = i915_vm_get(engine->gt->vm);
408
409 /* NB ce->signal_link/lock is used under RCU */
410 spin_lock_init(&ce->signal_lock);
411 INIT_LIST_HEAD(&ce->signals);
412
413 mutex_init(&ce->pin_mutex);
414
415 spin_lock_init(&ce->guc_state.lock);
416 INIT_LIST_HEAD(&ce->guc_state.fences);
417 INIT_LIST_HEAD(&ce->guc_state.requests);
418
419 ce->guc_id.id = GUC_INVALID_CONTEXT_ID;
420 INIT_LIST_HEAD(&ce->guc_id.link);
421
422 INIT_LIST_HEAD(&ce->destroyed_link);
423
424 INIT_LIST_HEAD(&ce->parallel.child_list);
425
426 /*
427 * Initialize fence to be complete as this is expected to be complete
428 * unless there is a pending schedule disable outstanding.
429 */
430 i915_sw_fence_init(&ce->guc_state.blocked,
431 sw_fence_dummy_notify);
432 i915_sw_fence_commit(&ce->guc_state.blocked);
433
434 i915_active_init(&ce->active,
435 __intel_context_active, __intel_context_retire, 0);
436}
437
438void intel_context_fini(struct intel_context *ce)
439{
440 struct intel_context *child, *next;
441
442 if (ce->timeline)
443 intel_timeline_put(ce->timeline);
444 i915_vm_put(ce->vm);
445
446 /* Need to put the creation ref for the children */
447 if (intel_context_is_parent(ce))
448 for_each_child_safe(ce, child, next)
449 intel_context_put(child);
450
451 mutex_destroy(&ce->pin_mutex);
452 i915_active_fini(&ce->active);
453 i915_sw_fence_fini(&ce->guc_state.blocked);
454}
455
456void i915_context_module_exit(void)
457{
458 kmem_cache_destroy(slab_ce);
459}
460
461int __init i915_context_module_init(void)
462{
463 slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
464 if (!slab_ce)
465 return -ENOMEM;
466
467 return 0;
468}
469
470void intel_context_enter_engine(struct intel_context *ce)
471{
472 intel_engine_pm_get(ce->engine);
473 intel_timeline_enter(ce->timeline);
474}
475
476void intel_context_exit_engine(struct intel_context *ce)
477{
478 intel_timeline_exit(ce->timeline);
479 intel_engine_pm_put(ce->engine);
480}
481
482int intel_context_prepare_remote_request(struct intel_context *ce,
483 struct i915_request *rq)
484{
485 struct intel_timeline *tl = ce->timeline;
486 int err;
487
488 /* Only suitable for use in remotely modifying this context */
489 GEM_BUG_ON(rq->context == ce);
490
491 if (rcu_access_pointer(rq->timeline) != tl) { /* timeline sharing! */
492 /* Queue this switch after current activity by this context. */
493 err = i915_active_fence_set(&tl->last_request, rq);
494 if (err)
495 return err;
496 }
497
498 /*
499 * Guarantee context image and the timeline remains pinned until the
500 * modifying request is retired by setting the ce activity tracker.
501 *
502 * But we only need to take one pin on the account of it. Or in other
503 * words transfer the pinned ce object to tracked active request.
504 */
505 GEM_BUG_ON(i915_active_is_idle(&ce->active));
506 return i915_active_add_request(&ce->active, rq);
507}
508
509struct i915_request *intel_context_create_request(struct intel_context *ce)
510{
511 struct i915_gem_ww_ctx ww;
512 struct i915_request *rq;
513 int err;
514
515 i915_gem_ww_ctx_init(&ww, true);
516retry:
517 err = intel_context_pin_ww(ce, &ww);
518 if (!err) {
519 rq = i915_request_create(ce);
520 intel_context_unpin(ce);
521 } else if (err == -EDEADLK) {
522 err = i915_gem_ww_ctx_backoff(&ww);
523 if (!err)
524 goto retry;
525 rq = ERR_PTR(err);
526 } else {
527 rq = ERR_PTR(err);
528 }
529
530 i915_gem_ww_ctx_fini(&ww);
531
532 if (IS_ERR(rq))
533 return rq;
534
535 /*
536 * timeline->mutex should be the inner lock, but is used as outer lock.
537 * Hack around this to shut up lockdep in selftests..
538 */
539 lockdep_unpin_lock(&ce->timeline->mutex, rq->cookie);
540 mutex_release(&ce->timeline->mutex.dep_map, _RET_IP_);
541 mutex_acquire(&ce->timeline->mutex.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
542 rq->cookie = lockdep_pin_lock(&ce->timeline->mutex);
543
544 return rq;
545}
546
547struct i915_request *intel_context_get_active_request(struct intel_context *ce)
548{
549 struct intel_context *parent = intel_context_to_parent(ce);
550 struct i915_request *rq, *active = NULL;
551 unsigned long flags;
552
553 GEM_BUG_ON(!intel_engine_uses_guc(ce->engine));
554
555 /*
556 * We search the parent list to find an active request on the submitted
557 * context. The parent list contains the requests for all the contexts
558 * in the relationship so we have to do a compare of each request's
559 * context.
560 */
561 spin_lock_irqsave(&parent->guc_state.lock, flags);
562 list_for_each_entry_reverse(rq, &parent->guc_state.requests,
563 sched.link) {
564 if (rq->context != ce)
565 continue;
566 if (i915_request_completed(rq))
567 break;
568
569 active = rq;
570 }
571 if (active)
572 active = i915_request_get_rcu(active);
573 spin_unlock_irqrestore(&parent->guc_state.lock, flags);
574
575 return active;
576}
577
578void intel_context_bind_parent_child(struct intel_context *parent,
579 struct intel_context *child)
580{
581 /*
582 * Callers responsibility to validate that this function is used
583 * correctly but we use GEM_BUG_ON here ensure that they do.
584 */
585 GEM_BUG_ON(intel_context_is_pinned(parent));
586 GEM_BUG_ON(intel_context_is_child(parent));
587 GEM_BUG_ON(intel_context_is_pinned(child));
588 GEM_BUG_ON(intel_context_is_child(child));
589 GEM_BUG_ON(intel_context_is_parent(child));
590
591 parent->parallel.child_index = parent->parallel.number_children++;
592 list_add_tail(&child->parallel.child_link,
593 &parent->parallel.child_list);
594 child->parallel.parent = parent;
595}
596
597u64 intel_context_get_total_runtime_ns(struct intel_context *ce)
598{
599 u64 total, active;
600
601 if (ce->ops->update_stats)
602 ce->ops->update_stats(ce);
603
604 total = ce->stats.runtime.total;
605 if (ce->ops->flags & COPS_RUNTIME_CYCLES)
606 total *= ce->engine->gt->clock_period_ns;
607
608 active = READ_ONCE(ce->stats.active);
609 if (active)
610 active = intel_context_clock() - active;
611
612 return total + active;
613}
614
615u64 intel_context_get_avg_runtime_ns(struct intel_context *ce)
616{
617 u64 avg = ewma_runtime_read(&ce->stats.runtime.avg);
618
619 if (ce->ops->flags & COPS_RUNTIME_CYCLES)
620 avg *= ce->engine->gt->clock_period_ns;
621
622 return avg;
623}
624
625bool intel_context_ban(struct intel_context *ce, struct i915_request *rq)
626{
627 bool ret = intel_context_set_banned(ce);
628
629 trace_intel_context_ban(ce);
630
631 if (ce->ops->revoke)
632 ce->ops->revoke(ce, rq,
633 INTEL_CONTEXT_BANNED_PREEMPT_TIMEOUT_MS);
634
635 return ret;
636}
637
638bool intel_context_revoke(struct intel_context *ce)
639{
640 bool ret = intel_context_set_exiting(ce);
641
642 if (ce->ops->revoke)
643 ce->ops->revoke(ce, NULL, ce->engine->props.preempt_timeout_ms);
644
645 return ret;
646}
647
648#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
649#include "selftest_context.c"
650#endif