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

source code of linux/drivers/gpu/drm/i915/gt/intel_context.c