File: | dev/pci/drm/i915/i915_request.c |
Warning: | line 1847, column 21 Value stored to 'ring' during its initialization is never read |
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1 | /* |
2 | * Copyright © 2008-2015 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/dma-fence-array.h> |
26 | #include <linux/dma-fence-chain.h> |
27 | #include <linux/irq_work.h> |
28 | #include <linux/prefetch.h> |
29 | #include <linux/sched.h> |
30 | #include <linux/sched/clock.h> |
31 | #include <linux/sched/signal.h> |
32 | #include <linux/sched/mm.h> |
33 | |
34 | #include "gem/i915_gem_context.h" |
35 | #include "gt/intel_breadcrumbs.h" |
36 | #include "gt/intel_context.h" |
37 | #include "gt/intel_engine.h" |
38 | #include "gt/intel_engine_heartbeat.h" |
39 | #include "gt/intel_engine_regs.h" |
40 | #include "gt/intel_gpu_commands.h" |
41 | #include "gt/intel_reset.h" |
42 | #include "gt/intel_ring.h" |
43 | #include "gt/intel_rps.h" |
44 | |
45 | #include "i915_active.h" |
46 | #include "i915_deps.h" |
47 | #include "i915_driver.h" |
48 | #include "i915_drv.h" |
49 | #include "i915_trace.h" |
50 | #include "intel_pm.h" |
51 | |
52 | struct execute_cb { |
53 | struct irq_work work; |
54 | struct i915_sw_fence *fence; |
55 | struct i915_request *signal; |
56 | }; |
57 | |
58 | static struct pool slab_requests; |
59 | static struct pool slab_execute_cbs; |
60 | |
61 | static const char *i915_fence_get_driver_name(struct dma_fence *fence) |
62 | { |
63 | return dev_name(to_request(fence)->i915->drm.dev)""; |
64 | } |
65 | |
66 | static const char *i915_fence_get_timeline_name(struct dma_fence *fence) |
67 | { |
68 | const struct i915_gem_context *ctx; |
69 | |
70 | /* |
71 | * The timeline struct (as part of the ppgtt underneath a context) |
72 | * may be freed when the request is no longer in use by the GPU. |
73 | * We could extend the life of a context to beyond that of all |
74 | * fences, possibly keeping the hw resource around indefinitely, |
75 | * or we just give them a false name. Since |
76 | * dma_fence_ops.get_timeline_name is a debug feature, the occasional |
77 | * lie seems justifiable. |
78 | */ |
79 | if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) |
80 | return "signaled"; |
81 | |
82 | ctx = i915_request_gem_context(to_request(fence)); |
83 | if (!ctx) |
84 | return "[" DRIVER_NAME"i915" "]"; |
85 | |
86 | return ctx->name; |
87 | } |
88 | |
89 | static bool_Bool i915_fence_signaled(struct dma_fence *fence) |
90 | { |
91 | return i915_request_completed(to_request(fence)); |
92 | } |
93 | |
94 | static bool_Bool i915_fence_enable_signaling(struct dma_fence *fence) |
95 | { |
96 | return i915_request_enable_breadcrumb(to_request(fence)); |
97 | } |
98 | |
99 | static signed long i915_fence_wait(struct dma_fence *fence, |
100 | bool_Bool interruptible, |
101 | signed long timeout) |
102 | { |
103 | return i915_request_wait_timeout(to_request(fence), |
104 | interruptible | I915_WAIT_PRIORITY(1UL << (1)), |
105 | timeout); |
106 | } |
107 | |
108 | #ifdef __linux__ |
109 | struct kmem_cache *i915_request_slab_cache(void) |
110 | { |
111 | return slab_requests; |
112 | } |
113 | #else |
114 | struct pool *i915_request_slab_cache(void) |
115 | { |
116 | return &slab_requests; |
117 | } |
118 | #endif |
119 | |
120 | static void i915_fence_release(struct dma_fence *fence) |
121 | { |
122 | struct i915_request *rq = to_request(fence); |
123 | |
124 | GEM_BUG_ON(rq->guc_prio != GUC_PRIO_INIT &&((void)0) |
125 | rq->guc_prio != GUC_PRIO_FINI)((void)0); |
126 | |
127 | i915_request_free_capture_list(fetch_and_zero(&rq->capture_list)({ typeof(*&rq->capture_list) __T = *(&rq->capture_list ); *(&rq->capture_list) = (typeof(*&rq->capture_list ))0; __T; })); |
128 | if (rq->batch_res) { |
129 | i915_vma_resource_put(rq->batch_res); |
130 | rq->batch_res = NULL((void *)0); |
131 | } |
132 | |
133 | /* |
134 | * The request is put onto a RCU freelist (i.e. the address |
135 | * is immediately reused), mark the fences as being freed now. |
136 | * Otherwise the debugobjects for the fences are only marked as |
137 | * freed when the slab cache itself is freed, and so we would get |
138 | * caught trying to reuse dead objects. |
139 | */ |
140 | i915_sw_fence_fini(&rq->submit); |
141 | i915_sw_fence_fini(&rq->semaphore); |
142 | |
143 | /* |
144 | * Keep one request on each engine for reserved use under mempressure. |
145 | * |
146 | * We do not hold a reference to the engine here and so have to be |
147 | * very careful in what rq->engine we poke. The virtual engine is |
148 | * referenced via the rq->context and we released that ref during |
149 | * i915_request_retire(), ergo we must not dereference a virtual |
150 | * engine here. Not that we would want to, as the only consumer of |
151 | * the reserved engine->request_pool is the power management parking, |
152 | * which must-not-fail, and that is only run on the physical engines. |
153 | * |
154 | * Since the request must have been executed to be have completed, |
155 | * we know that it will have been processed by the HW and will |
156 | * not be unsubmitted again, so rq->engine and rq->execution_mask |
157 | * at this point is stable. rq->execution_mask will be a single |
158 | * bit if the last and _only_ engine it could execution on was a |
159 | * physical engine, if it's multiple bits then it started on and |
160 | * could still be on a virtual engine. Thus if the mask is not a |
161 | * power-of-two we assume that rq->engine may still be a virtual |
162 | * engine and so a dangling invalid pointer that we cannot dereference |
163 | * |
164 | * For example, consider the flow of a bonded request through a virtual |
165 | * engine. The request is created with a wide engine mask (all engines |
166 | * that we might execute on). On processing the bond, the request mask |
167 | * is reduced to one or more engines. If the request is subsequently |
168 | * bound to a single engine, it will then be constrained to only |
169 | * execute on that engine and never returned to the virtual engine |
170 | * after timeslicing away, see __unwind_incomplete_requests(). Thus we |
171 | * know that if the rq->execution_mask is a single bit, rq->engine |
172 | * can be a physical engine with the exact corresponding mask. |
173 | */ |
174 | if (is_power_of_2(rq->execution_mask)(((rq->execution_mask) != 0) && (((rq->execution_mask ) - 1) & (rq->execution_mask)) == 0) && |
175 | !cmpxchg(&rq->engine->request_pool, NULL, rq)__sync_val_compare_and_swap(&rq->engine->request_pool , ((void *)0), rq)) |
176 | return; |
177 | |
178 | #ifdef __linux__ |
179 | kmem_cache_free(slab_requests, rq); |
180 | #else |
181 | pool_put(&slab_requests, rq); |
182 | #endif |
183 | } |
184 | |
185 | const struct dma_fence_ops i915_fence_ops = { |
186 | .get_driver_name = i915_fence_get_driver_name, |
187 | .get_timeline_name = i915_fence_get_timeline_name, |
188 | .enable_signaling = i915_fence_enable_signaling, |
189 | .signaled = i915_fence_signaled, |
190 | .wait = i915_fence_wait, |
191 | .release = i915_fence_release, |
192 | }; |
193 | |
194 | static void irq_execute_cb(struct irq_work *wrk) |
195 | { |
196 | struct execute_cb *cb = container_of(wrk, typeof(*cb), work)({ const __typeof( ((typeof(*cb) *)0)->work ) *__mptr = (wrk ); (typeof(*cb) *)( (char *)__mptr - __builtin_offsetof(typeof (*cb), work) );}); |
197 | |
198 | i915_sw_fence_complete(cb->fence); |
199 | #ifdef __linux__ |
200 | kmem_cache_free(slab_execute_cbs, cb); |
201 | #else |
202 | pool_put(&slab_execute_cbs, cb); |
203 | #endif |
204 | } |
205 | |
206 | static __always_inlineinline __attribute__((__always_inline__)) void |
207 | __notify_execute_cb(struct i915_request *rq, bool_Bool (*fn)(struct irq_work *wrk)) |
208 | { |
209 | struct execute_cb *cb, *cn; |
210 | |
211 | if (llist_empty(&rq->execute_cb)) |
212 | return; |
213 | |
214 | llist_for_each_entry_safe(cb, cn,for (cb = ({ const __typeof( ((__typeof(*cb) *)0)->work.node .llist ) *__mptr = ((llist_del_all(&rq->execute_cb))); (__typeof(*cb) *)( (char *)__mptr - __builtin_offsetof(__typeof (*cb), work.node.llist) );}); ((char *)(cb) + __builtin_offsetof (typeof(*(cb)), work.node.llist)) != ((void *)0) && ( cn = ({ const __typeof( ((__typeof(*cb) *)0)->work.node.llist ) *__mptr = (cb->work.node.llist.next); (__typeof(*cb) *) ( (char *)__mptr - __builtin_offsetof(__typeof(*cb), work.node .llist) );}), cb); cb = cn) |
215 | llist_del_all(&rq->execute_cb),for (cb = ({ const __typeof( ((__typeof(*cb) *)0)->work.node .llist ) *__mptr = ((llist_del_all(&rq->execute_cb))); (__typeof(*cb) *)( (char *)__mptr - __builtin_offsetof(__typeof (*cb), work.node.llist) );}); ((char *)(cb) + __builtin_offsetof (typeof(*(cb)), work.node.llist)) != ((void *)0) && ( cn = ({ const __typeof( ((__typeof(*cb) *)0)->work.node.llist ) *__mptr = (cb->work.node.llist.next); (__typeof(*cb) *) ( (char *)__mptr - __builtin_offsetof(__typeof(*cb), work.node .llist) );}), cb); cb = cn) |
216 | work.node.llist)for (cb = ({ const __typeof( ((__typeof(*cb) *)0)->work.node .llist ) *__mptr = ((llist_del_all(&rq->execute_cb))); (__typeof(*cb) *)( (char *)__mptr - __builtin_offsetof(__typeof (*cb), work.node.llist) );}); ((char *)(cb) + __builtin_offsetof (typeof(*(cb)), work.node.llist)) != ((void *)0) && ( cn = ({ const __typeof( ((__typeof(*cb) *)0)->work.node.llist ) *__mptr = (cb->work.node.llist.next); (__typeof(*cb) *) ( (char *)__mptr - __builtin_offsetof(__typeof(*cb), work.node .llist) );}), cb); cb = cn) |
217 | fn(&cb->work); |
218 | } |
219 | |
220 | static void __notify_execute_cb_irq(struct i915_request *rq) |
221 | { |
222 | __notify_execute_cb(rq, irq_work_queue); |
223 | } |
224 | |
225 | static bool_Bool irq_work_imm(struct irq_work *wrk) |
226 | { |
227 | #ifdef __linux__ |
228 | wrk->func(wrk); |
229 | #else |
230 | wrk->task.t_func(wrk); |
231 | #endif |
232 | return false0; |
233 | } |
234 | |
235 | void i915_request_notify_execute_cb_imm(struct i915_request *rq) |
236 | { |
237 | __notify_execute_cb(rq, irq_work_imm); |
238 | } |
239 | |
240 | static void __i915_request_fill(struct i915_request *rq, u8 val) |
241 | { |
242 | void *vaddr = rq->ring->vaddr; |
243 | u32 head; |
244 | |
245 | head = rq->infix; |
246 | if (rq->postfix < head) { |
247 | memset(vaddr + head, val, rq->ring->size - head)__builtin_memset((vaddr + head), (val), (rq->ring->size - head)); |
248 | head = 0; |
249 | } |
250 | memset(vaddr + head, val, rq->postfix - head)__builtin_memset((vaddr + head), (val), (rq->postfix - head )); |
251 | } |
252 | |
253 | /** |
254 | * i915_request_active_engine |
255 | * @rq: request to inspect |
256 | * @active: pointer in which to return the active engine |
257 | * |
258 | * Fills the currently active engine to the @active pointer if the request |
259 | * is active and still not completed. |
260 | * |
261 | * Returns true if request was active or false otherwise. |
262 | */ |
263 | bool_Bool |
264 | i915_request_active_engine(struct i915_request *rq, |
265 | struct intel_engine_cs **active) |
266 | { |
267 | struct intel_engine_cs *engine, *locked; |
268 | bool_Bool ret = false0; |
269 | |
270 | /* |
271 | * Serialise with __i915_request_submit() so that it sees |
272 | * is-banned?, or we know the request is already inflight. |
273 | * |
274 | * Note that rq->engine is unstable, and so we double |
275 | * check that we have acquired the lock on the final engine. |
276 | */ |
277 | locked = READ_ONCE(rq->engine)({ typeof(rq->engine) __tmp = *(volatile typeof(rq->engine ) *)&(rq->engine); membar_datadep_consumer(); __tmp; } ); |
278 | spin_lock_irq(&locked->sched_engine->lock)mtx_enter(&locked->sched_engine->lock); |
279 | while (unlikely(locked != (engine = READ_ONCE(rq->engine)))__builtin_expect(!!(locked != (engine = ({ typeof(rq->engine ) __tmp = *(volatile typeof(rq->engine) *)&(rq->engine ); membar_datadep_consumer(); __tmp; }))), 0)) { |
280 | spin_unlock(&locked->sched_engine->lock)mtx_leave(&locked->sched_engine->lock); |
281 | locked = engine; |
282 | spin_lock(&locked->sched_engine->lock)mtx_enter(&locked->sched_engine->lock); |
283 | } |
284 | |
285 | if (i915_request_is_active(rq)) { |
286 | if (!__i915_request_is_complete(rq)) |
287 | *active = locked; |
288 | ret = true1; |
289 | } |
290 | |
291 | spin_unlock_irq(&locked->sched_engine->lock)mtx_leave(&locked->sched_engine->lock); |
292 | |
293 | return ret; |
294 | } |
295 | |
296 | static void __rq_init_watchdog(struct i915_request *rq) |
297 | { |
298 | rq->watchdog.timer.to_func = NULL((void *)0); |
299 | } |
300 | |
301 | #ifdef __linux__ |
302 | |
303 | static enum hrtimer_restart __rq_watchdog_expired(struct hrtimer *hrtimer) |
304 | { |
305 | struct i915_request *rq = |
306 | container_of(hrtimer, struct i915_request, watchdog.timer)({ const __typeof( ((struct i915_request *)0)->watchdog.timer ) *__mptr = (hrtimer); (struct i915_request *)( (char *)__mptr - __builtin_offsetof(struct i915_request, watchdog.timer) ); }); |
307 | struct intel_gt *gt = rq->engine->gt; |
308 | |
309 | if (!i915_request_completed(rq)) { |
310 | if (llist_add(&rq->watchdog.link, >->watchdog.list)) |
311 | schedule_work(>->watchdog.work); |
312 | } else { |
313 | i915_request_put(rq); |
314 | } |
315 | |
316 | return HRTIMER_NORESTART; |
317 | } |
318 | |
319 | #else |
320 | |
321 | static void |
322 | __rq_watchdog_expired(void *arg) |
323 | { |
324 | struct i915_request *rq = (struct i915_request *)arg; |
325 | struct intel_gt *gt = rq->engine->gt; |
326 | |
327 | if (!i915_request_completed(rq)) { |
328 | if (llist_add(&rq->watchdog.link, >->watchdog.list)) |
329 | schedule_work(>->watchdog.work); |
330 | } else { |
331 | i915_request_put(rq); |
332 | } |
333 | } |
334 | |
335 | #endif |
336 | |
337 | static void __rq_arm_watchdog(struct i915_request *rq) |
338 | { |
339 | struct i915_request_watchdog *wdg = &rq->watchdog; |
340 | struct intel_context *ce = rq->context; |
341 | |
342 | if (!ce->watchdog.timeout_us) |
343 | return; |
344 | |
345 | i915_request_get(rq); |
346 | |
347 | #ifdef __linux__ |
348 | hrtimer_init(&wdg->timer, CLOCK_MONOTONIC3, HRTIMER_MODE_REL1); |
349 | wdg->timer.function = __rq_watchdog_expired; |
350 | hrtimer_start_range_ns(&wdg->timer, |
351 | ns_to_ktime(ce->watchdog.timeout_us * |
352 | NSEC_PER_USEC1000L), |
353 | NSEC_PER_MSEC1000000L, |
354 | HRTIMER_MODE_REL1); |
355 | #else |
356 | timeout_set(&wdg->timer, __rq_watchdog_expired, rq); |
357 | timeout_add_msec(&wdg->timer, 1); |
358 | #endif |
359 | } |
360 | |
361 | static void __rq_cancel_watchdog(struct i915_request *rq) |
362 | { |
363 | struct i915_request_watchdog *wdg = &rq->watchdog; |
364 | |
365 | if (wdg->timer.to_func && hrtimer_try_to_cancel(&wdg->timer)timeout_del(&wdg->timer) > 0) |
366 | i915_request_put(rq); |
367 | } |
368 | |
369 | #if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)1 |
370 | |
371 | /** |
372 | * i915_request_free_capture_list - Free a capture list |
373 | * @capture: Pointer to the first list item or NULL |
374 | * |
375 | */ |
376 | void i915_request_free_capture_list(struct i915_capture_list *capture) |
377 | { |
378 | while (capture) { |
379 | struct i915_capture_list *next = capture->next; |
380 | |
381 | i915_vma_resource_put(capture->vma_res); |
382 | kfree(capture); |
383 | capture = next; |
384 | } |
385 | } |
386 | |
387 | #define assert_capture_list_is_null(_rq)((void)0) GEM_BUG_ON((_rq)->capture_list)((void)0) |
388 | |
389 | #define clear_capture_list(_rq)((_rq)->capture_list = ((void *)0)) ((_rq)->capture_list = NULL((void *)0)) |
390 | |
391 | #else |
392 | |
393 | #define i915_request_free_capture_list(_a) do {} while (0) |
394 | |
395 | #define assert_capture_list_is_null(_a)((void)0) do {} while (0) |
396 | |
397 | #define clear_capture_list(_rq)((_rq)->capture_list = ((void *)0)) do {} while (0) |
398 | |
399 | #endif |
400 | |
401 | bool_Bool i915_request_retire(struct i915_request *rq) |
402 | { |
403 | if (!__i915_request_is_complete(rq)) |
404 | return false0; |
405 | |
406 | RQ_TRACE(rq, "\n")do { const struct i915_request *rq__ = (rq); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
407 | |
408 | GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit))((void)0); |
409 | trace_i915_request_retire(rq); |
410 | i915_request_mark_complete(rq); |
411 | |
412 | __rq_cancel_watchdog(rq); |
413 | |
414 | /* |
415 | * We know the GPU must have read the request to have |
416 | * sent us the seqno + interrupt, so use the position |
417 | * of tail of the request to update the last known position |
418 | * of the GPU head. |
419 | * |
420 | * Note this requires that we are always called in request |
421 | * completion order. |
422 | */ |
423 | GEM_BUG_ON(!list_is_first(&rq->link,((void)0) |
424 | &i915_request_timeline(rq)->requests))((void)0); |
425 | if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)0) |
426 | /* Poison before we release our space in the ring */ |
427 | __i915_request_fill(rq, POISON_FREE0xdf); |
428 | rq->ring->head = rq->postfix; |
429 | |
430 | if (!i915_request_signaled(rq)) { |
431 | spin_lock_irq(&rq->lock)mtx_enter(&rq->lock); |
432 | dma_fence_signal_locked(&rq->fence); |
433 | spin_unlock_irq(&rq->lock)mtx_leave(&rq->lock); |
434 | } |
435 | |
436 | if (test_and_set_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags)) |
437 | intel_rps_dec_waiters(&rq->engine->gt->rps); |
438 | |
439 | /* |
440 | * We only loosely track inflight requests across preemption, |
441 | * and so we may find ourselves attempting to retire a _completed_ |
442 | * request that we have removed from the HW and put back on a run |
443 | * queue. |
444 | * |
445 | * As we set I915_FENCE_FLAG_ACTIVE on the request, this should be |
446 | * after removing the breadcrumb and signaling it, so that we do not |
447 | * inadvertently attach the breadcrumb to a completed request. |
448 | */ |
449 | rq->engine->remove_active_request(rq); |
450 | GEM_BUG_ON(!llist_empty(&rq->execute_cb))((void)0); |
451 | |
452 | __list_del_entry(&rq->link)list_del(&rq->link); /* poison neither prev/next (RCU walks) */ |
453 | |
454 | intel_context_exit(rq->context); |
455 | intel_context_unpin(rq->context); |
456 | |
457 | i915_sched_node_fini(&rq->sched); |
458 | i915_request_put(rq); |
459 | |
460 | return true1; |
461 | } |
462 | |
463 | void i915_request_retire_upto(struct i915_request *rq) |
464 | { |
465 | struct intel_timeline * const tl = i915_request_timeline(rq); |
466 | struct i915_request *tmp; |
467 | |
468 | RQ_TRACE(rq, "\n")do { const struct i915_request *rq__ = (rq); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
469 | GEM_BUG_ON(!__i915_request_is_complete(rq))((void)0); |
470 | |
471 | do { |
472 | tmp = list_first_entry(&tl->requests, typeof(*tmp), link)({ const __typeof( ((typeof(*tmp) *)0)->link ) *__mptr = ( (&tl->requests)->next); (typeof(*tmp) *)( (char *)__mptr - __builtin_offsetof(typeof(*tmp), link) );}); |
473 | GEM_BUG_ON(!i915_request_completed(tmp))((void)0); |
474 | } while (i915_request_retire(tmp) && tmp != rq); |
475 | } |
476 | |
477 | static struct i915_request * const * |
478 | __engine_active(struct intel_engine_cs *engine) |
479 | { |
480 | return READ_ONCE(engine->execlists.active)({ typeof(engine->execlists.active) __tmp = *(volatile typeof (engine->execlists.active) *)&(engine->execlists.active ); membar_datadep_consumer(); __tmp; }); |
481 | } |
482 | |
483 | static bool_Bool __request_in_flight(const struct i915_request *signal) |
484 | { |
485 | struct i915_request * const *port, *rq; |
486 | bool_Bool inflight = false0; |
487 | |
488 | if (!i915_request_is_ready(signal)) |
489 | return false0; |
490 | |
491 | /* |
492 | * Even if we have unwound the request, it may still be on |
493 | * the GPU (preempt-to-busy). If that request is inside an |
494 | * unpreemptible critical section, it will not be removed. Some |
495 | * GPU functions may even be stuck waiting for the paired request |
496 | * (__await_execution) to be submitted and cannot be preempted |
497 | * until the bond is executing. |
498 | * |
499 | * As we know that there are always preemption points between |
500 | * requests, we know that only the currently executing request |
501 | * may be still active even though we have cleared the flag. |
502 | * However, we can't rely on our tracking of ELSP[0] to know |
503 | * which request is currently active and so maybe stuck, as |
504 | * the tracking maybe an event behind. Instead assume that |
505 | * if the context is still inflight, then it is still active |
506 | * even if the active flag has been cleared. |
507 | * |
508 | * To further complicate matters, if there a pending promotion, the HW |
509 | * may either perform a context switch to the second inflight execlists, |
510 | * or it may switch to the pending set of execlists. In the case of the |
511 | * latter, it may send the ACK and we process the event copying the |
512 | * pending[] over top of inflight[], _overwriting_ our *active. Since |
513 | * this implies the HW is arbitrating and not struck in *active, we do |
514 | * not worry about complete accuracy, but we do require no read/write |
515 | * tearing of the pointer [the read of the pointer must be valid, even |
516 | * as the array is being overwritten, for which we require the writes |
517 | * to avoid tearing.] |
518 | * |
519 | * Note that the read of *execlists->active may race with the promotion |
520 | * of execlists->pending[] to execlists->inflight[], overwritting |
521 | * the value at *execlists->active. This is fine. The promotion implies |
522 | * that we received an ACK from the HW, and so the context is not |
523 | * stuck -- if we do not see ourselves in *active, the inflight status |
524 | * is valid. If instead we see ourselves being copied into *active, |
525 | * we are inflight and may signal the callback. |
526 | */ |
527 | if (!intel_context_inflight(signal->context)({ unsigned long __v = (unsigned long)(({ typeof((signal-> context)->inflight) __tmp = *(volatile typeof((signal-> context)->inflight) *)&((signal->context)->inflight ); membar_datadep_consumer(); __tmp; })); (typeof(({ typeof(( signal->context)->inflight) __tmp = *(volatile typeof(( signal->context)->inflight) *)&((signal->context )->inflight); membar_datadep_consumer(); __tmp; })))(__v & -(1UL << (3))); })) |
528 | return false0; |
529 | |
530 | rcu_read_lock(); |
531 | for (port = __engine_active(signal->engine); |
532 | (rq = READ_ONCE(*port)({ typeof(*port) __tmp = *(volatile typeof(*port) *)&(*port ); membar_datadep_consumer(); __tmp; })); /* may race with promotion of pending[] */ |
533 | port++) { |
534 | if (rq->context == signal->context) { |
535 | inflight = i915_seqno_passed(rq->fence.seqno, |
536 | signal->fence.seqno); |
537 | break; |
538 | } |
539 | } |
540 | rcu_read_unlock(); |
541 | |
542 | return inflight; |
543 | } |
544 | |
545 | static int |
546 | __await_execution(struct i915_request *rq, |
547 | struct i915_request *signal, |
548 | gfp_t gfp) |
549 | { |
550 | struct execute_cb *cb; |
551 | |
552 | if (i915_request_is_active(signal)) |
553 | return 0; |
554 | |
555 | #ifdef __linux__ |
556 | cb = kmem_cache_alloc(slab_execute_cbs, gfp); |
557 | #else |
558 | cb = pool_get(&slab_execute_cbs, |
559 | (gfp & GFP_NOWAIT0x0002) ? PR_NOWAIT0x0002 : PR_WAITOK0x0001); |
560 | #endif |
561 | if (!cb) |
562 | return -ENOMEM12; |
563 | |
564 | cb->fence = &rq->submit; |
565 | i915_sw_fence_await(cb->fence); |
566 | init_irq_work(&cb->work, irq_execute_cb); |
567 | |
568 | /* |
569 | * Register the callback first, then see if the signaler is already |
570 | * active. This ensures that if we race with the |
571 | * __notify_execute_cb from i915_request_submit() and we are not |
572 | * included in that list, we get a second bite of the cherry and |
573 | * execute it ourselves. After this point, a future |
574 | * i915_request_submit() will notify us. |
575 | * |
576 | * In i915_request_retire() we set the ACTIVE bit on a completed |
577 | * request (then flush the execute_cb). So by registering the |
578 | * callback first, then checking the ACTIVE bit, we serialise with |
579 | * the completed/retired request. |
580 | */ |
581 | if (llist_add(&cb->work.node.llist, &signal->execute_cb)) { |
582 | if (i915_request_is_active(signal) || |
583 | __request_in_flight(signal)) |
584 | i915_request_notify_execute_cb_imm(signal); |
585 | } |
586 | |
587 | return 0; |
588 | } |
589 | |
590 | static bool_Bool fatal_error(int error) |
591 | { |
592 | switch (error) { |
593 | case 0: /* not an error! */ |
594 | case -EAGAIN35: /* innocent victim of a GT reset (__i915_request_reset) */ |
595 | case -ETIMEDOUT60: /* waiting for Godot (timer_i915_sw_fence_wake) */ |
596 | return false0; |
597 | default: |
598 | return true1; |
599 | } |
600 | } |
601 | |
602 | void __i915_request_skip(struct i915_request *rq) |
603 | { |
604 | GEM_BUG_ON(!fatal_error(rq->fence.error))((void)0); |
605 | |
606 | if (rq->infix == rq->postfix) |
607 | return; |
608 | |
609 | RQ_TRACE(rq, "error: %d\n", rq->fence.error)do { const struct i915_request *rq__ = (rq); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
610 | |
611 | /* |
612 | * As this request likely depends on state from the lost |
613 | * context, clear out all the user operations leaving the |
614 | * breadcrumb at the end (so we get the fence notifications). |
615 | */ |
616 | __i915_request_fill(rq, 0); |
617 | rq->infix = rq->postfix; |
618 | } |
619 | |
620 | bool_Bool i915_request_set_error_once(struct i915_request *rq, int error) |
621 | { |
622 | int old; |
623 | |
624 | GEM_BUG_ON(!IS_ERR_VALUE((long)error))((void)0); |
625 | |
626 | if (i915_request_signaled(rq)) |
627 | return false0; |
628 | |
629 | old = READ_ONCE(rq->fence.error)({ typeof(rq->fence.error) __tmp = *(volatile typeof(rq-> fence.error) *)&(rq->fence.error); membar_datadep_consumer (); __tmp; }); |
630 | do { |
631 | if (fatal_error(old)) |
632 | return false0; |
633 | } while (!try_cmpxchg(&rq->fence.error, &old, error)({ __typeof(&rq->fence.error) __op = (__typeof((&rq ->fence.error)))(&old); __typeof(*(&rq->fence.error )) __o = *__op; __typeof(*(&rq->fence.error)) __p = __sync_val_compare_and_swap ((&rq->fence.error), (__o), (error)); if (__p != __o) * __op = __p; (__p == __o); })); |
634 | |
635 | return true1; |
636 | } |
637 | |
638 | struct i915_request *i915_request_mark_eio(struct i915_request *rq) |
639 | { |
640 | if (__i915_request_is_complete(rq)) |
641 | return NULL((void *)0); |
642 | |
643 | GEM_BUG_ON(i915_request_signaled(rq))((void)0); |
644 | |
645 | /* As soon as the request is completed, it may be retired */ |
646 | rq = i915_request_get(rq); |
647 | |
648 | i915_request_set_error_once(rq, -EIO5); |
649 | i915_request_mark_complete(rq); |
650 | |
651 | return rq; |
652 | } |
653 | |
654 | bool_Bool __i915_request_submit(struct i915_request *request) |
655 | { |
656 | struct intel_engine_cs *engine = request->engine; |
657 | bool_Bool result = false0; |
658 | |
659 | RQ_TRACE(request, "\n")do { const struct i915_request *rq__ = (request); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
660 | |
661 | GEM_BUG_ON(!irqs_disabled())((void)0); |
662 | lockdep_assert_held(&engine->sched_engine->lock)do { (void)(&engine->sched_engine->lock); } while(0 ); |
663 | |
664 | /* |
665 | * With the advent of preempt-to-busy, we frequently encounter |
666 | * requests that we have unsubmitted from HW, but left running |
667 | * until the next ack and so have completed in the meantime. On |
668 | * resubmission of that completed request, we can skip |
669 | * updating the payload, and execlists can even skip submitting |
670 | * the request. |
671 | * |
672 | * We must remove the request from the caller's priority queue, |
673 | * and the caller must only call us when the request is in their |
674 | * priority queue, under the sched_engine->lock. This ensures that the |
675 | * request has *not* yet been retired and we can safely move |
676 | * the request into the engine->active.list where it will be |
677 | * dropped upon retiring. (Otherwise if resubmit a *retired* |
678 | * request, this would be a horrible use-after-free.) |
679 | */ |
680 | if (__i915_request_is_complete(request)) { |
681 | list_del_init(&request->sched.link); |
682 | goto active; |
683 | } |
684 | |
685 | if (unlikely(!intel_context_is_schedulable(request->context))__builtin_expect(!!(!intel_context_is_schedulable(request-> context)), 0)) |
686 | i915_request_set_error_once(request, -EIO5); |
687 | |
688 | if (unlikely(fatal_error(request->fence.error))__builtin_expect(!!(fatal_error(request->fence.error)), 0)) |
689 | __i915_request_skip(request); |
690 | |
691 | /* |
692 | * Are we using semaphores when the gpu is already saturated? |
693 | * |
694 | * Using semaphores incurs a cost in having the GPU poll a |
695 | * memory location, busywaiting for it to change. The continual |
696 | * memory reads can have a noticeable impact on the rest of the |
697 | * system with the extra bus traffic, stalling the cpu as it too |
698 | * tries to access memory across the bus (perf stat -e bus-cycles). |
699 | * |
700 | * If we installed a semaphore on this request and we only submit |
701 | * the request after the signaler completed, that indicates the |
702 | * system is overloaded and using semaphores at this time only |
703 | * increases the amount of work we are doing. If so, we disable |
704 | * further use of semaphores until we are idle again, whence we |
705 | * optimistically try again. |
706 | */ |
707 | if (request->sched.semaphores && |
708 | i915_sw_fence_signaled(&request->semaphore)) |
709 | engine->saturated |= request->sched.semaphores; |
710 | |
711 | engine->emit_fini_breadcrumb(request, |
712 | request->ring->vaddr + request->postfix); |
713 | |
714 | trace_i915_request_execute(request); |
715 | if (engine->bump_serial) |
716 | engine->bump_serial(engine); |
717 | else |
718 | engine->serial++; |
719 | |
720 | result = true1; |
721 | |
722 | GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags))((void)0); |
723 | engine->add_active_request(request); |
724 | active: |
725 | clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); |
726 | set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags); |
727 | |
728 | /* |
729 | * XXX Rollback bonded-execution on __i915_request_unsubmit()? |
730 | * |
731 | * In the future, perhaps when we have an active time-slicing scheduler, |
732 | * it will be interesting to unsubmit parallel execution and remove |
733 | * busywaits from the GPU until their master is restarted. This is |
734 | * quite hairy, we have to carefully rollback the fence and do a |
735 | * preempt-to-idle cycle on the target engine, all the while the |
736 | * master execute_cb may refire. |
737 | */ |
738 | __notify_execute_cb_irq(request); |
739 | |
740 | /* We may be recursing from the signal callback of another i915 fence */ |
741 | if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) |
742 | i915_request_enable_breadcrumb(request); |
743 | |
744 | return result; |
745 | } |
746 | |
747 | void i915_request_submit(struct i915_request *request) |
748 | { |
749 | struct intel_engine_cs *engine = request->engine; |
750 | unsigned long flags; |
751 | |
752 | /* Will be called from irq-context when using foreign fences. */ |
753 | spin_lock_irqsave(&engine->sched_engine->lock, flags)do { flags = 0; mtx_enter(&engine->sched_engine->lock ); } while (0); |
754 | |
755 | __i915_request_submit(request); |
756 | |
757 | spin_unlock_irqrestore(&engine->sched_engine->lock, flags)do { (void)(flags); mtx_leave(&engine->sched_engine-> lock); } while (0); |
758 | } |
759 | |
760 | void __i915_request_unsubmit(struct i915_request *request) |
761 | { |
762 | struct intel_engine_cs *engine = request->engine; |
763 | |
764 | /* |
765 | * Only unwind in reverse order, required so that the per-context list |
766 | * is kept in seqno/ring order. |
767 | */ |
768 | RQ_TRACE(request, "\n")do { const struct i915_request *rq__ = (request); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
769 | |
770 | GEM_BUG_ON(!irqs_disabled())((void)0); |
771 | lockdep_assert_held(&engine->sched_engine->lock)do { (void)(&engine->sched_engine->lock); } while(0 ); |
772 | |
773 | /* |
774 | * Before we remove this breadcrumb from the signal list, we have |
775 | * to ensure that a concurrent dma_fence_enable_signaling() does not |
776 | * attach itself. We first mark the request as no longer active and |
777 | * make sure that is visible to other cores, and then remove the |
778 | * breadcrumb if attached. |
779 | */ |
780 | GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags))((void)0); |
781 | clear_bit_unlock(I915_FENCE_FLAG_ACTIVE, &request->fence.flags); |
782 | if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) |
783 | i915_request_cancel_breadcrumb(request); |
784 | |
785 | /* We've already spun, don't charge on resubmitting. */ |
786 | if (request->sched.semaphores && __i915_request_has_started(request)) |
787 | request->sched.semaphores = 0; |
788 | |
789 | /* |
790 | * We don't need to wake_up any waiters on request->execute, they |
791 | * will get woken by any other event or us re-adding this request |
792 | * to the engine timeline (__i915_request_submit()). The waiters |
793 | * should be quite adapt at finding that the request now has a new |
794 | * global_seqno to the one they went to sleep on. |
795 | */ |
796 | } |
797 | |
798 | void i915_request_unsubmit(struct i915_request *request) |
799 | { |
800 | struct intel_engine_cs *engine = request->engine; |
801 | unsigned long flags; |
802 | |
803 | /* Will be called from irq-context when using foreign fences. */ |
804 | spin_lock_irqsave(&engine->sched_engine->lock, flags)do { flags = 0; mtx_enter(&engine->sched_engine->lock ); } while (0); |
805 | |
806 | __i915_request_unsubmit(request); |
807 | |
808 | spin_unlock_irqrestore(&engine->sched_engine->lock, flags)do { (void)(flags); mtx_leave(&engine->sched_engine-> lock); } while (0); |
809 | } |
810 | |
811 | void i915_request_cancel(struct i915_request *rq, int error) |
812 | { |
813 | if (!i915_request_set_error_once(rq, error)) |
814 | return; |
815 | |
816 | set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags); |
817 | |
818 | intel_context_cancel_request(rq->context, rq); |
819 | } |
820 | |
821 | static int |
822 | submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state) |
823 | { |
824 | struct i915_request *request = |
825 | container_of(fence, typeof(*request), submit)({ const __typeof( ((typeof(*request) *)0)->submit ) *__mptr = (fence); (typeof(*request) *)( (char *)__mptr - __builtin_offsetof (typeof(*request), submit) );}); |
826 | |
827 | switch (state) { |
828 | case FENCE_COMPLETE: |
829 | trace_i915_request_submit(request); |
830 | |
831 | if (unlikely(fence->error)__builtin_expect(!!(fence->error), 0)) |
832 | i915_request_set_error_once(request, fence->error); |
833 | else |
834 | __rq_arm_watchdog(request); |
835 | |
836 | /* |
837 | * We need to serialize use of the submit_request() callback |
838 | * with its hotplugging performed during an emergency |
839 | * i915_gem_set_wedged(). We use the RCU mechanism to mark the |
840 | * critical section in order to force i915_gem_set_wedged() to |
841 | * wait until the submit_request() is completed before |
842 | * proceeding. |
843 | */ |
844 | rcu_read_lock(); |
845 | request->engine->submit_request(request); |
846 | rcu_read_unlock(); |
847 | break; |
848 | |
849 | case FENCE_FREE: |
850 | i915_request_put(request); |
851 | break; |
852 | } |
853 | |
854 | return NOTIFY_DONE0; |
855 | } |
856 | |
857 | static int |
858 | semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state) |
859 | { |
860 | struct i915_request *rq = container_of(fence, typeof(*rq), semaphore)({ const __typeof( ((typeof(*rq) *)0)->semaphore ) *__mptr = (fence); (typeof(*rq) *)( (char *)__mptr - __builtin_offsetof (typeof(*rq), semaphore) );}); |
861 | |
862 | switch (state) { |
863 | case FENCE_COMPLETE: |
864 | break; |
865 | |
866 | case FENCE_FREE: |
867 | i915_request_put(rq); |
868 | break; |
869 | } |
870 | |
871 | return NOTIFY_DONE0; |
872 | } |
873 | |
874 | static void retire_requests(struct intel_timeline *tl) |
875 | { |
876 | struct i915_request *rq, *rn; |
877 | |
878 | list_for_each_entry_safe(rq, rn, &tl->requests, link)for (rq = ({ const __typeof( ((__typeof(*rq) *)0)->link ) * __mptr = ((&tl->requests)->next); (__typeof(*rq) *) ( (char *)__mptr - __builtin_offsetof(__typeof(*rq), link) ); }), rn = ({ const __typeof( ((__typeof(*rq) *)0)->link ) * __mptr = (rq->link.next); (__typeof(*rq) *)( (char *)__mptr - __builtin_offsetof(__typeof(*rq), link) );}); &rq-> link != (&tl->requests); rq = rn, rn = ({ const __typeof ( ((__typeof(*rn) *)0)->link ) *__mptr = (rn->link.next ); (__typeof(*rn) *)( (char *)__mptr - __builtin_offsetof(__typeof (*rn), link) );})) |
879 | if (!i915_request_retire(rq)) |
880 | break; |
881 | } |
882 | |
883 | static void __i915_request_ctor(void *); |
884 | |
885 | static noinline__attribute__((__noinline__)) struct i915_request * |
886 | request_alloc_slow(struct intel_timeline *tl, |
887 | struct i915_request **rsvd, |
888 | gfp_t gfp) |
889 | { |
890 | struct i915_request *rq; |
891 | |
892 | /* If we cannot wait, dip into our reserves */ |
893 | if (!gfpflags_allow_blocking(gfp)) { |
894 | rq = xchg(rsvd, NULL)__sync_lock_test_and_set(rsvd, ((void *)0)); |
895 | if (!rq) /* Use the normal failure path for one final WARN */ |
896 | goto out; |
897 | |
898 | return rq; |
899 | } |
900 | |
901 | if (list_empty(&tl->requests)) |
902 | goto out; |
903 | |
904 | /* Move our oldest request to the slab-cache (if not in use!) */ |
905 | rq = list_first_entry(&tl->requests, typeof(*rq), link)({ const __typeof( ((typeof(*rq) *)0)->link ) *__mptr = (( &tl->requests)->next); (typeof(*rq) *)( (char *)__mptr - __builtin_offsetof(typeof(*rq), link) );}); |
906 | i915_request_retire(rq); |
907 | |
908 | #ifdef __linux__ |
909 | rq = kmem_cache_alloc(slab_requests, |
910 | gfp | __GFP_RETRY_MAYFAIL0 | __GFP_NOWARN0); |
911 | #else |
912 | rq = pool_get(&slab_requests, |
913 | (gfp & GFP_NOWAIT0x0002) ? PR_NOWAIT0x0002 : PR_WAITOK0x0001); |
914 | if (rq) |
915 | __i915_request_ctor(rq); |
916 | #endif |
917 | if (rq) |
918 | return rq; |
919 | |
920 | /* Ratelimit ourselves to prevent oom from malicious clients */ |
921 | rq = list_last_entry(&tl->requests, typeof(*rq), link)({ const __typeof( ((typeof(*rq) *)0)->link ) *__mptr = (( &tl->requests)->prev); (typeof(*rq) *)( (char *)__mptr - __builtin_offsetof(typeof(*rq), link) );}); |
922 | cond_synchronize_rcu(rq->rcustate); |
923 | |
924 | /* Retire our old requests in the hope that we free some */ |
925 | retire_requests(tl); |
926 | |
927 | out: |
928 | #ifdef __linux__ |
929 | return kmem_cache_alloc(slab_requests, gfp); |
930 | #else |
931 | rq = pool_get(&slab_requests, |
932 | (gfp & GFP_NOWAIT0x0002) ? PR_NOWAIT0x0002 : PR_WAITOK0x0001); |
933 | if (rq) |
934 | __i915_request_ctor(rq); |
935 | return rq; |
936 | #endif |
937 | } |
938 | |
939 | static void __i915_request_ctor(void *arg) |
940 | { |
941 | struct i915_request *rq = arg; |
942 | |
943 | /* |
944 | * witness does not understand spin_lock_nested() |
945 | * order reversal in i915 with this lock |
946 | */ |
947 | mtx_init_flags(&rq->lock, IPL_TTY, NULL, MTX_NOWITNESS)do { (void)(((void *)0)); (void)(0x01); __mtx_init((&rq-> lock), ((((0x9)) > 0x0 && ((0x9)) < 0x9) ? 0x9 : ((0x9)))); } while (0); |
948 | i915_sched_node_init(&rq->sched); |
949 | i915_sw_fence_init(&rq->submit, submit_notify)do { extern char _ctassert[(!((submit_notify) == ((void *)0)) ) ? 1 : -1 ] __attribute__((__unused__)); __i915_sw_fence_init ((&rq->submit), (submit_notify), ((void *)0), ((void * )0)); } while (0); |
950 | i915_sw_fence_init(&rq->semaphore, semaphore_notify)do { extern char _ctassert[(!((semaphore_notify) == ((void *) 0))) ? 1 : -1 ] __attribute__((__unused__)); __i915_sw_fence_init ((&rq->semaphore), (semaphore_notify), ((void *)0), (( void *)0)); } while (0); |
951 | |
952 | clear_capture_list(rq)((rq)->capture_list = ((void *)0)); |
953 | rq->batch_res = NULL((void *)0); |
954 | |
955 | init_llist_head(&rq->execute_cb); |
956 | } |
957 | |
958 | #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)0 |
959 | #define clear_batch_ptr(_rq)do {} while (0) ((_rq)->batch = NULL((void *)0)) |
960 | #else |
961 | #define clear_batch_ptr(_a)do {} while (0) do {} while (0) |
962 | #endif |
963 | |
964 | struct i915_request * |
965 | __i915_request_create(struct intel_context *ce, gfp_t gfp) |
966 | { |
967 | struct intel_timeline *tl = ce->timeline; |
968 | struct i915_request *rq; |
969 | u32 seqno; |
970 | int ret; |
971 | |
972 | might_alloc(gfp); |
973 | |
974 | /* Check that the caller provided an already pinned context */ |
975 | __intel_context_pin(ce); |
976 | |
977 | /* |
978 | * Beware: Dragons be flying overhead. |
979 | * |
980 | * We use RCU to look up requests in flight. The lookups may |
981 | * race with the request being allocated from the slab freelist. |
982 | * That is the request we are writing to here, may be in the process |
983 | * of being read by __i915_active_request_get_rcu(). As such, |
984 | * we have to be very careful when overwriting the contents. During |
985 | * the RCU lookup, we change chase the request->engine pointer, |
986 | * read the request->global_seqno and increment the reference count. |
987 | * |
988 | * The reference count is incremented atomically. If it is zero, |
989 | * the lookup knows the request is unallocated and complete. Otherwise, |
990 | * it is either still in use, or has been reallocated and reset |
991 | * with dma_fence_init(). This increment is safe for release as we |
992 | * check that the request we have a reference to and matches the active |
993 | * request. |
994 | * |
995 | * Before we increment the refcount, we chase the request->engine |
996 | * pointer. We must not call kmem_cache_zalloc() or else we set |
997 | * that pointer to NULL and cause a crash during the lookup. If |
998 | * we see the request is completed (based on the value of the |
999 | * old engine and seqno), the lookup is complete and reports NULL. |
1000 | * If we decide the request is not completed (new engine or seqno), |
1001 | * then we grab a reference and double check that it is still the |
1002 | * active request - which it won't be and restart the lookup. |
1003 | * |
1004 | * Do not use kmem_cache_zalloc() here! |
1005 | */ |
1006 | #ifdef __linux__ |
1007 | rq = kmem_cache_alloc(slab_requests, |
1008 | gfp | __GFP_RETRY_MAYFAIL0 | __GFP_NOWARN0); |
1009 | #else |
1010 | rq = pool_get(&slab_requests, |
1011 | (gfp & GFP_NOWAIT0x0002) ? PR_NOWAIT0x0002 : PR_WAITOK0x0001); |
1012 | if (rq) |
1013 | __i915_request_ctor(rq); |
1014 | #endif |
1015 | if (unlikely(!rq)__builtin_expect(!!(!rq), 0)) { |
1016 | rq = request_alloc_slow(tl, &ce->engine->request_pool, gfp); |
1017 | if (!rq) { |
1018 | ret = -ENOMEM12; |
1019 | goto err_unreserve; |
1020 | } |
1021 | } |
1022 | |
1023 | rq->context = ce; |
1024 | rq->engine = ce->engine; |
1025 | rq->ring = ce->ring; |
1026 | rq->execution_mask = ce->engine->mask; |
1027 | rq->i915 = ce->engine->i915; |
1028 | |
1029 | ret = intel_timeline_get_seqno(tl, rq, &seqno); |
1030 | if (ret) |
1031 | goto err_free; |
1032 | |
1033 | dma_fence_init(&rq->fence, &i915_fence_ops, &rq->lock, |
1034 | tl->fence_context, seqno); |
1035 | |
1036 | RCU_INIT_POINTER(rq->timeline, tl)do { (rq->timeline) = (tl); } while(0); |
1037 | rq->hwsp_seqno = tl->hwsp_seqno; |
1038 | GEM_BUG_ON(__i915_request_is_complete(rq))((void)0); |
1039 | |
1040 | rq->rcustate = get_state_synchronize_rcu()0; /* acts as smp_mb() */ |
1041 | |
1042 | rq->guc_prio = GUC_PRIO_INIT0xff; |
1043 | |
1044 | /* We bump the ref for the fence chain */ |
1045 | i915_sw_fence_reinit(&i915_request_get(rq)->submit); |
1046 | i915_sw_fence_reinit(&i915_request_get(rq)->semaphore); |
1047 | |
1048 | i915_sched_node_reinit(&rq->sched); |
1049 | |
1050 | /* No zalloc, everything must be cleared after use */ |
1051 | clear_batch_ptr(rq)do {} while (0); |
1052 | __rq_init_watchdog(rq); |
1053 | assert_capture_list_is_null(rq)((void)0); |
1054 | GEM_BUG_ON(!llist_empty(&rq->execute_cb))((void)0); |
1055 | GEM_BUG_ON(rq->batch_res)((void)0); |
1056 | |
1057 | /* |
1058 | * Reserve space in the ring buffer for all the commands required to |
1059 | * eventually emit this request. This is to guarantee that the |
1060 | * i915_request_add() call can't fail. Note that the reserve may need |
1061 | * to be redone if the request is not actually submitted straight |
1062 | * away, e.g. because a GPU scheduler has deferred it. |
1063 | * |
1064 | * Note that due to how we add reserved_space to intel_ring_begin() |
1065 | * we need to double our request to ensure that if we need to wrap |
1066 | * around inside i915_request_add() there is sufficient space at |
1067 | * the beginning of the ring as well. |
1068 | */ |
1069 | rq->reserved_space = |
1070 | 2 * rq->engine->emit_fini_breadcrumb_dw * sizeof(u32); |
1071 | |
1072 | /* |
1073 | * Record the position of the start of the request so that |
1074 | * should we detect the updated seqno part-way through the |
1075 | * GPU processing the request, we never over-estimate the |
1076 | * position of the head. |
1077 | */ |
1078 | rq->head = rq->ring->emit; |
1079 | |
1080 | ret = rq->engine->request_alloc(rq); |
1081 | if (ret) |
1082 | goto err_unwind; |
1083 | |
1084 | rq->infix = rq->ring->emit; /* end of header; start of user payload */ |
1085 | |
1086 | intel_context_mark_active(ce); |
1087 | list_add_tail_rcu(&rq->link, &tl->requests)list_add_tail(&rq->link, &tl->requests); |
1088 | |
1089 | return rq; |
1090 | |
1091 | err_unwind: |
1092 | ce->ring->emit = rq->head; |
1093 | |
1094 | /* Make sure we didn't add ourselves to external state before freeing */ |
1095 | GEM_BUG_ON(!list_empty(&rq->sched.signalers_list))((void)0); |
1096 | GEM_BUG_ON(!list_empty(&rq->sched.waiters_list))((void)0); |
1097 | |
1098 | err_free: |
1099 | #ifdef __linux__ |
1100 | kmem_cache_free(slab_requests, rq); |
1101 | #else |
1102 | pool_put(&slab_requests, rq); |
1103 | #endif |
1104 | err_unreserve: |
1105 | intel_context_unpin(ce); |
1106 | return ERR_PTR(ret); |
1107 | } |
1108 | |
1109 | struct i915_request * |
1110 | i915_request_create(struct intel_context *ce) |
1111 | { |
1112 | struct i915_request *rq; |
1113 | struct intel_timeline *tl; |
1114 | |
1115 | tl = intel_context_timeline_lock(ce); |
1116 | if (IS_ERR(tl)) |
1117 | return ERR_CAST(tl); |
1118 | |
1119 | /* Move our oldest request to the slab-cache (if not in use!) */ |
1120 | rq = list_first_entry(&tl->requests, typeof(*rq), link)({ const __typeof( ((typeof(*rq) *)0)->link ) *__mptr = (( &tl->requests)->next); (typeof(*rq) *)( (char *)__mptr - __builtin_offsetof(typeof(*rq), link) );}); |
1121 | if (!list_is_last(&rq->link, &tl->requests)) |
1122 | i915_request_retire(rq); |
1123 | |
1124 | intel_context_enter(ce); |
1125 | rq = __i915_request_create(ce, GFP_KERNEL(0x0001 | 0x0004)); |
1126 | intel_context_exit(ce); /* active reference transferred to request */ |
1127 | if (IS_ERR(rq)) |
1128 | goto err_unlock; |
1129 | |
1130 | /* Check that we do not interrupt ourselves with a new request */ |
1131 | rq->cookie = lockdep_pin_lock(&tl->mutex)({ struct pin_cookie pc = {}; pc; }); |
1132 | |
1133 | return rq; |
1134 | |
1135 | err_unlock: |
1136 | intel_context_timeline_unlock(tl); |
1137 | return rq; |
1138 | } |
1139 | |
1140 | static int |
1141 | i915_request_await_start(struct i915_request *rq, struct i915_request *signal) |
1142 | { |
1143 | struct dma_fence *fence; |
1144 | int err; |
1145 | |
1146 | if (i915_request_timeline(rq) == rcu_access_pointer(signal->timeline)(signal->timeline)) |
1147 | return 0; |
1148 | |
1149 | if (i915_request_started(signal)) |
1150 | return 0; |
1151 | |
1152 | /* |
1153 | * The caller holds a reference on @signal, but we do not serialise |
1154 | * against it being retired and removed from the lists. |
1155 | * |
1156 | * We do not hold a reference to the request before @signal, and |
1157 | * so must be very careful to ensure that it is not _recycled_ as |
1158 | * we follow the link backwards. |
1159 | */ |
1160 | fence = NULL((void *)0); |
1161 | rcu_read_lock(); |
1162 | do { |
1163 | struct list_head *pos = READ_ONCE(signal->link.prev)({ typeof(signal->link.prev) __tmp = *(volatile typeof(signal ->link.prev) *)&(signal->link.prev); membar_datadep_consumer (); __tmp; }); |
1164 | struct i915_request *prev; |
1165 | |
1166 | /* Confirm signal has not been retired, the link is valid */ |
1167 | if (unlikely(__i915_request_has_started(signal))__builtin_expect(!!(__i915_request_has_started(signal)), 0)) |
1168 | break; |
1169 | |
1170 | /* Is signal the earliest request on its timeline? */ |
1171 | if (pos == &rcu_dereference(signal->timeline)(signal->timeline)->requests) |
1172 | break; |
1173 | |
1174 | /* |
1175 | * Peek at the request before us in the timeline. That |
1176 | * request will only be valid before it is retired, so |
1177 | * after acquiring a reference to it, confirm that it is |
1178 | * still part of the signaler's timeline. |
1179 | */ |
1180 | prev = list_entry(pos, typeof(*prev), link)({ const __typeof( ((typeof(*prev) *)0)->link ) *__mptr = ( pos); (typeof(*prev) *)( (char *)__mptr - __builtin_offsetof( typeof(*prev), link) );}); |
1181 | if (!i915_request_get_rcu(prev)) |
1182 | break; |
1183 | |
1184 | /* After the strong barrier, confirm prev is still attached */ |
1185 | if (unlikely(READ_ONCE(prev->link.next) != &signal->link)__builtin_expect(!!(({ typeof(prev->link.next) __tmp = *(volatile typeof(prev->link.next) *)&(prev->link.next); membar_datadep_consumer (); __tmp; }) != &signal->link), 0)) { |
1186 | i915_request_put(prev); |
1187 | break; |
1188 | } |
1189 | |
1190 | fence = &prev->fence; |
1191 | } while (0); |
1192 | rcu_read_unlock(); |
1193 | if (!fence) |
1194 | return 0; |
1195 | |
1196 | err = 0; |
1197 | if (!intel_timeline_sync_is_later(i915_request_timeline(rq), fence)) |
1198 | err = i915_sw_fence_await_dma_fence(&rq->submit, |
1199 | fence, 0, |
1200 | I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1201 | dma_fence_put(fence); |
1202 | |
1203 | return err; |
1204 | } |
1205 | |
1206 | static intel_engine_mask_t |
1207 | already_busywaiting(struct i915_request *rq) |
1208 | { |
1209 | /* |
1210 | * Polling a semaphore causes bus traffic, delaying other users of |
1211 | * both the GPU and CPU. We want to limit the impact on others, |
1212 | * while taking advantage of early submission to reduce GPU |
1213 | * latency. Therefore we restrict ourselves to not using more |
1214 | * than one semaphore from each source, and not using a semaphore |
1215 | * if we have detected the engine is saturated (i.e. would not be |
1216 | * submitted early and cause bus traffic reading an already passed |
1217 | * semaphore). |
1218 | * |
1219 | * See the are-we-too-late? check in __i915_request_submit(). |
1220 | */ |
1221 | return rq->sched.semaphores | READ_ONCE(rq->engine->saturated)({ typeof(rq->engine->saturated) __tmp = *(volatile typeof (rq->engine->saturated) *)&(rq->engine->saturated ); membar_datadep_consumer(); __tmp; }); |
1222 | } |
1223 | |
1224 | static int |
1225 | __emit_semaphore_wait(struct i915_request *to, |
1226 | struct i915_request *from, |
1227 | u32 seqno) |
1228 | { |
1229 | const int has_token = GRAPHICS_VER(to->engine->i915)((&(to->engine->i915)->__runtime)->graphics.ip .ver) >= 12; |
1230 | u32 hwsp_offset; |
1231 | int len, err; |
1232 | u32 *cs; |
1233 | |
1234 | GEM_BUG_ON(GRAPHICS_VER(to->engine->i915) < 8)((void)0); |
1235 | GEM_BUG_ON(i915_request_has_initial_breadcrumb(to))((void)0); |
1236 | |
1237 | /* We need to pin the signaler's HWSP until we are finished reading. */ |
1238 | err = intel_timeline_read_hwsp(from, to, &hwsp_offset); |
1239 | if (err) |
1240 | return err; |
1241 | |
1242 | len = 4; |
1243 | if (has_token) |
1244 | len += 2; |
1245 | |
1246 | cs = intel_ring_begin(to, len); |
1247 | if (IS_ERR(cs)) |
1248 | return PTR_ERR(cs); |
1249 | |
1250 | /* |
1251 | * Using greater-than-or-equal here means we have to worry |
1252 | * about seqno wraparound. To side step that issue, we swap |
1253 | * the timeline HWSP upon wrapping, so that everyone listening |
1254 | * for the old (pre-wrap) values do not see the much smaller |
1255 | * (post-wrap) values than they were expecting (and so wait |
1256 | * forever). |
1257 | */ |
1258 | *cs++ = (MI_SEMAPHORE_WAIT(((0x0) << 29) | (0x1c) << 23 | (2)) | |
1259 | MI_SEMAPHORE_GLOBAL_GTT(1<<22) | |
1260 | MI_SEMAPHORE_POLL(1 << 15) | |
1261 | MI_SEMAPHORE_SAD_GTE_SDD(1 << 12)) + |
1262 | has_token; |
1263 | *cs++ = seqno; |
1264 | *cs++ = hwsp_offset; |
1265 | *cs++ = 0; |
1266 | if (has_token) { |
1267 | *cs++ = 0; |
1268 | *cs++ = MI_NOOP(((0x0) << 29) | (0) << 23 | (0)); |
1269 | } |
1270 | |
1271 | intel_ring_advance(to, cs); |
1272 | return 0; |
1273 | } |
1274 | |
1275 | static bool_Bool |
1276 | can_use_semaphore_wait(struct i915_request *to, struct i915_request *from) |
1277 | { |
1278 | return to->engine->gt->ggtt == from->engine->gt->ggtt; |
1279 | } |
1280 | |
1281 | static int |
1282 | emit_semaphore_wait(struct i915_request *to, |
1283 | struct i915_request *from, |
1284 | gfp_t gfp) |
1285 | { |
1286 | const intel_engine_mask_t mask = READ_ONCE(from->engine)({ typeof(from->engine) __tmp = *(volatile typeof(from-> engine) *)&(from->engine); membar_datadep_consumer(); __tmp ; })->mask; |
1287 | struct i915_sw_fence *wait = &to->submit; |
1288 | |
1289 | if (!can_use_semaphore_wait(to, from)) |
1290 | goto await_fence; |
1291 | |
1292 | if (!intel_context_use_semaphores(to->context)) |
1293 | goto await_fence; |
1294 | |
1295 | if (i915_request_has_initial_breadcrumb(to)) |
1296 | goto await_fence; |
1297 | |
1298 | /* |
1299 | * If this or its dependents are waiting on an external fence |
1300 | * that may fail catastrophically, then we want to avoid using |
1301 | * sempahores as they bypass the fence signaling metadata, and we |
1302 | * lose the fence->error propagation. |
1303 | */ |
1304 | if (from->sched.flags & I915_SCHED_HAS_EXTERNAL_CHAIN(1UL << (0))) |
1305 | goto await_fence; |
1306 | |
1307 | /* Just emit the first semaphore we see as request space is limited. */ |
1308 | if (already_busywaiting(to) & mask) |
1309 | goto await_fence; |
1310 | |
1311 | if (i915_request_await_start(to, from) < 0) |
1312 | goto await_fence; |
1313 | |
1314 | /* Only submit our spinner after the signaler is running! */ |
1315 | if (__await_execution(to, from, gfp)) |
1316 | goto await_fence; |
1317 | |
1318 | if (__emit_semaphore_wait(to, from, from->fence.seqno)) |
1319 | goto await_fence; |
1320 | |
1321 | to->sched.semaphores |= mask; |
1322 | wait = &to->semaphore; |
1323 | |
1324 | await_fence: |
1325 | return i915_sw_fence_await_dma_fence(wait, |
1326 | &from->fence, 0, |
1327 | I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1328 | } |
1329 | |
1330 | static bool_Bool intel_timeline_sync_has_start(struct intel_timeline *tl, |
1331 | struct dma_fence *fence) |
1332 | { |
1333 | return __intel_timeline_sync_is_later(tl, |
1334 | fence->context, |
1335 | fence->seqno - 1); |
1336 | } |
1337 | |
1338 | static int intel_timeline_sync_set_start(struct intel_timeline *tl, |
1339 | const struct dma_fence *fence) |
1340 | { |
1341 | return __intel_timeline_sync_set(tl, fence->context, fence->seqno - 1); |
1342 | } |
1343 | |
1344 | static int |
1345 | __i915_request_await_execution(struct i915_request *to, |
1346 | struct i915_request *from) |
1347 | { |
1348 | int err; |
1349 | |
1350 | GEM_BUG_ON(intel_context_is_barrier(from->context))((void)0); |
1351 | |
1352 | /* Submit both requests at the same time */ |
1353 | err = __await_execution(to, from, I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1354 | if (err) |
1355 | return err; |
1356 | |
1357 | /* Squash repeated depenendices to the same timelines */ |
1358 | if (intel_timeline_sync_has_start(i915_request_timeline(to), |
1359 | &from->fence)) |
1360 | return 0; |
1361 | |
1362 | /* |
1363 | * Wait until the start of this request. |
1364 | * |
1365 | * The execution cb fires when we submit the request to HW. But in |
1366 | * many cases this may be long before the request itself is ready to |
1367 | * run (consider that we submit 2 requests for the same context, where |
1368 | * the request of interest is behind an indefinite spinner). So we hook |
1369 | * up to both to reduce our queues and keep the execution lag minimised |
1370 | * in the worst case, though we hope that the await_start is elided. |
1371 | */ |
1372 | err = i915_request_await_start(to, from); |
1373 | if (err < 0) |
1374 | return err; |
1375 | |
1376 | /* |
1377 | * Ensure both start together [after all semaphores in signal] |
1378 | * |
1379 | * Now that we are queued to the HW at roughly the same time (thanks |
1380 | * to the execute cb) and are ready to run at roughly the same time |
1381 | * (thanks to the await start), our signaler may still be indefinitely |
1382 | * delayed by waiting on a semaphore from a remote engine. If our |
1383 | * signaler depends on a semaphore, so indirectly do we, and we do not |
1384 | * want to start our payload until our signaler also starts theirs. |
1385 | * So we wait. |
1386 | * |
1387 | * However, there is also a second condition for which we need to wait |
1388 | * for the precise start of the signaler. Consider that the signaler |
1389 | * was submitted in a chain of requests following another context |
1390 | * (with just an ordinary intra-engine fence dependency between the |
1391 | * two). In this case the signaler is queued to HW, but not for |
1392 | * immediate execution, and so we must wait until it reaches the |
1393 | * active slot. |
1394 | */ |
1395 | if (can_use_semaphore_wait(to, from) && |
1396 | intel_engine_has_semaphores(to->engine) && |
1397 | !i915_request_has_initial_breadcrumb(to)) { |
1398 | err = __emit_semaphore_wait(to, from, from->fence.seqno - 1); |
1399 | if (err < 0) |
1400 | return err; |
1401 | } |
1402 | |
1403 | /* Couple the dependency tree for PI on this exposed to->fence */ |
1404 | if (to->engine->sched_engine->schedule) { |
1405 | err = i915_sched_node_add_dependency(&to->sched, |
1406 | &from->sched, |
1407 | I915_DEPENDENCY_WEAK(1UL << (2))); |
1408 | if (err < 0) |
1409 | return err; |
1410 | } |
1411 | |
1412 | return intel_timeline_sync_set_start(i915_request_timeline(to), |
1413 | &from->fence); |
1414 | } |
1415 | |
1416 | static void mark_external(struct i915_request *rq) |
1417 | { |
1418 | /* |
1419 | * The downside of using semaphores is that we lose metadata passing |
1420 | * along the signaling chain. This is particularly nasty when we |
1421 | * need to pass along a fatal error such as EFAULT or EDEADLK. For |
1422 | * fatal errors we want to scrub the request before it is executed, |
1423 | * which means that we cannot preload the request onto HW and have |
1424 | * it wait upon a semaphore. |
1425 | */ |
1426 | rq->sched.flags |= I915_SCHED_HAS_EXTERNAL_CHAIN(1UL << (0)); |
1427 | } |
1428 | |
1429 | static int |
1430 | __i915_request_await_external(struct i915_request *rq, struct dma_fence *fence) |
1431 | { |
1432 | mark_external(rq); |
1433 | return i915_sw_fence_await_dma_fence(&rq->submit, fence, |
1434 | i915_fence_context_timeout(rq->engine->i915, |
1435 | fence->context), |
1436 | I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1437 | } |
1438 | |
1439 | static int |
1440 | i915_request_await_external(struct i915_request *rq, struct dma_fence *fence) |
1441 | { |
1442 | struct dma_fence *iter; |
1443 | int err = 0; |
1444 | |
1445 | if (!to_dma_fence_chain(fence)) |
1446 | return __i915_request_await_external(rq, fence); |
1447 | |
1448 | dma_fence_chain_for_each(iter, fence)for (iter = dma_fence_get(fence); iter != ((void *)0); iter = dma_fence_chain_walk(iter)) { |
1449 | struct dma_fence_chain *chain = to_dma_fence_chain(iter); |
1450 | |
1451 | if (!dma_fence_is_i915(chain->fence)) { |
1452 | err = __i915_request_await_external(rq, iter); |
1453 | break; |
1454 | } |
1455 | |
1456 | err = i915_request_await_dma_fence(rq, chain->fence); |
1457 | if (err < 0) |
1458 | break; |
1459 | } |
1460 | |
1461 | dma_fence_put(iter); |
1462 | return err; |
1463 | } |
1464 | |
1465 | static inline bool_Bool is_parallel_rq(struct i915_request *rq) |
1466 | { |
1467 | return intel_context_is_parallel(rq->context); |
1468 | } |
1469 | |
1470 | static inline struct intel_context *request_to_parent(struct i915_request *rq) |
1471 | { |
1472 | return intel_context_to_parent(rq->context); |
1473 | } |
1474 | |
1475 | static bool_Bool is_same_parallel_context(struct i915_request *to, |
1476 | struct i915_request *from) |
1477 | { |
1478 | if (is_parallel_rq(to)) |
1479 | return request_to_parent(to) == request_to_parent(from); |
1480 | |
1481 | return false0; |
1482 | } |
1483 | |
1484 | int |
1485 | i915_request_await_execution(struct i915_request *rq, |
1486 | struct dma_fence *fence) |
1487 | { |
1488 | struct dma_fence **child = &fence; |
1489 | unsigned int nchild = 1; |
1490 | int ret; |
1491 | |
1492 | if (dma_fence_is_array(fence)) { |
1493 | struct dma_fence_array *array = to_dma_fence_array(fence); |
1494 | |
1495 | /* XXX Error for signal-on-any fence arrays */ |
1496 | |
1497 | child = array->fences; |
1498 | nchild = array->num_fences; |
1499 | GEM_BUG_ON(!nchild)((void)0); |
1500 | } |
1501 | |
1502 | do { |
1503 | fence = *child++; |
1504 | if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) |
1505 | continue; |
1506 | |
1507 | if (fence->context == rq->fence.context) |
1508 | continue; |
1509 | |
1510 | /* |
1511 | * We don't squash repeated fence dependencies here as we |
1512 | * want to run our callback in all cases. |
1513 | */ |
1514 | |
1515 | if (dma_fence_is_i915(fence)) { |
1516 | if (is_same_parallel_context(rq, to_request(fence))) |
1517 | continue; |
1518 | ret = __i915_request_await_execution(rq, |
1519 | to_request(fence)); |
1520 | } else { |
1521 | ret = i915_request_await_external(rq, fence); |
1522 | } |
1523 | if (ret < 0) |
1524 | return ret; |
1525 | } while (--nchild); |
1526 | |
1527 | return 0; |
1528 | } |
1529 | |
1530 | static int |
1531 | await_request_submit(struct i915_request *to, struct i915_request *from) |
1532 | { |
1533 | /* |
1534 | * If we are waiting on a virtual engine, then it may be |
1535 | * constrained to execute on a single engine *prior* to submission. |
1536 | * When it is submitted, it will be first submitted to the virtual |
1537 | * engine and then passed to the physical engine. We cannot allow |
1538 | * the waiter to be submitted immediately to the physical engine |
1539 | * as it may then bypass the virtual request. |
1540 | */ |
1541 | if (to->engine == READ_ONCE(from->engine)({ typeof(from->engine) __tmp = *(volatile typeof(from-> engine) *)&(from->engine); membar_datadep_consumer(); __tmp ; })) |
1542 | return i915_sw_fence_await_sw_fence_gfp(&to->submit, |
1543 | &from->submit, |
1544 | I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1545 | else |
1546 | return __i915_request_await_execution(to, from); |
1547 | } |
1548 | |
1549 | static int |
1550 | i915_request_await_request(struct i915_request *to, struct i915_request *from) |
1551 | { |
1552 | int ret; |
1553 | |
1554 | GEM_BUG_ON(to == from)((void)0); |
1555 | GEM_BUG_ON(to->timeline == from->timeline)((void)0); |
1556 | |
1557 | if (i915_request_completed(from)) { |
1558 | i915_sw_fence_set_error_once(&to->submit, from->fence.error); |
1559 | return 0; |
1560 | } |
1561 | |
1562 | if (to->engine->sched_engine->schedule) { |
1563 | ret = i915_sched_node_add_dependency(&to->sched, |
1564 | &from->sched, |
1565 | I915_DEPENDENCY_EXTERNAL(1UL << (1))); |
1566 | if (ret < 0) |
1567 | return ret; |
1568 | } |
1569 | |
1570 | if (!intel_engine_uses_guc(to->engine) && |
1571 | is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask))(((to->execution_mask | ({ typeof(from->execution_mask) __tmp = *(volatile typeof(from->execution_mask) *)&(from ->execution_mask); membar_datadep_consumer(); __tmp; })) != 0) && (((to->execution_mask | ({ typeof(from-> execution_mask) __tmp = *(volatile typeof(from->execution_mask ) *)&(from->execution_mask); membar_datadep_consumer() ; __tmp; })) - 1) & (to->execution_mask | ({ typeof(from ->execution_mask) __tmp = *(volatile typeof(from->execution_mask ) *)&(from->execution_mask); membar_datadep_consumer() ; __tmp; }))) == 0)) |
1572 | ret = await_request_submit(to, from); |
1573 | else |
1574 | ret = emit_semaphore_wait(to, from, I915_FENCE_GFP((0x0001 | 0x0004) | 0 | 0)); |
1575 | if (ret < 0) |
1576 | return ret; |
1577 | |
1578 | return 0; |
1579 | } |
1580 | |
1581 | int |
1582 | i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence) |
1583 | { |
1584 | struct dma_fence **child = &fence; |
1585 | unsigned int nchild = 1; |
1586 | int ret; |
1587 | |
1588 | /* |
1589 | * Note that if the fence-array was created in signal-on-any mode, |
1590 | * we should *not* decompose it into its individual fences. However, |
1591 | * we don't currently store which mode the fence-array is operating |
1592 | * in. Fortunately, the only user of signal-on-any is private to |
1593 | * amdgpu and we should not see any incoming fence-array from |
1594 | * sync-file being in signal-on-any mode. |
1595 | */ |
1596 | if (dma_fence_is_array(fence)) { |
1597 | struct dma_fence_array *array = to_dma_fence_array(fence); |
1598 | |
1599 | child = array->fences; |
1600 | nchild = array->num_fences; |
1601 | GEM_BUG_ON(!nchild)((void)0); |
1602 | } |
1603 | |
1604 | do { |
1605 | fence = *child++; |
1606 | if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) |
1607 | continue; |
1608 | |
1609 | /* |
1610 | * Requests on the same timeline are explicitly ordered, along |
1611 | * with their dependencies, by i915_request_add() which ensures |
1612 | * that requests are submitted in-order through each ring. |
1613 | */ |
1614 | if (fence->context == rq->fence.context) |
1615 | continue; |
1616 | |
1617 | /* Squash repeated waits to the same timelines */ |
1618 | if (fence->context && |
1619 | intel_timeline_sync_is_later(i915_request_timeline(rq), |
1620 | fence)) |
1621 | continue; |
1622 | |
1623 | if (dma_fence_is_i915(fence)) { |
1624 | if (is_same_parallel_context(rq, to_request(fence))) |
1625 | continue; |
1626 | ret = i915_request_await_request(rq, to_request(fence)); |
1627 | } else { |
1628 | ret = i915_request_await_external(rq, fence); |
1629 | } |
1630 | if (ret < 0) |
1631 | return ret; |
1632 | |
1633 | /* Record the latest fence used against each timeline */ |
1634 | if (fence->context) |
1635 | intel_timeline_sync_set(i915_request_timeline(rq), |
1636 | fence); |
1637 | } while (--nchild); |
1638 | |
1639 | return 0; |
1640 | } |
1641 | |
1642 | /** |
1643 | * i915_request_await_deps - set this request to (async) wait upon a struct |
1644 | * i915_deps dma_fence collection |
1645 | * @rq: request we are wishing to use |
1646 | * @deps: The struct i915_deps containing the dependencies. |
1647 | * |
1648 | * Returns 0 if successful, negative error code on error. |
1649 | */ |
1650 | int i915_request_await_deps(struct i915_request *rq, const struct i915_deps *deps) |
1651 | { |
1652 | int i, err; |
1653 | |
1654 | for (i = 0; i < deps->num_deps; ++i) { |
1655 | err = i915_request_await_dma_fence(rq, deps->fences[i]); |
1656 | if (err) |
1657 | return err; |
1658 | } |
1659 | |
1660 | return 0; |
1661 | } |
1662 | |
1663 | /** |
1664 | * i915_request_await_object - set this request to (async) wait upon a bo |
1665 | * @to: request we are wishing to use |
1666 | * @obj: object which may be in use on another ring. |
1667 | * @write: whether the wait is on behalf of a writer |
1668 | * |
1669 | * This code is meant to abstract object synchronization with the GPU. |
1670 | * Conceptually we serialise writes between engines inside the GPU. |
1671 | * We only allow one engine to write into a buffer at any time, but |
1672 | * multiple readers. To ensure each has a coherent view of memory, we must: |
1673 | * |
1674 | * - If there is an outstanding write request to the object, the new |
1675 | * request must wait for it to complete (either CPU or in hw, requests |
1676 | * on the same ring will be naturally ordered). |
1677 | * |
1678 | * - If we are a write request (pending_write_domain is set), the new |
1679 | * request must wait for outstanding read requests to complete. |
1680 | * |
1681 | * Returns 0 if successful, else propagates up the lower layer error. |
1682 | */ |
1683 | int |
1684 | i915_request_await_object(struct i915_request *to, |
1685 | struct drm_i915_gem_object *obj, |
1686 | bool_Bool write) |
1687 | { |
1688 | struct dma_resv_iter cursor; |
1689 | struct dma_fence *fence; |
1690 | int ret = 0; |
1691 | |
1692 | dma_resv_for_each_fence(&cursor, obj->base.resv,for (dma_resv_iter_begin(&cursor, obj->base.resv, dma_resv_usage_rw (write)), fence = dma_resv_iter_first(&cursor); fence; fence = dma_resv_iter_next(&cursor)) |
1693 | dma_resv_usage_rw(write), fence)for (dma_resv_iter_begin(&cursor, obj->base.resv, dma_resv_usage_rw (write)), fence = dma_resv_iter_first(&cursor); fence; fence = dma_resv_iter_next(&cursor)) { |
1694 | ret = i915_request_await_dma_fence(to, fence); |
1695 | if (ret) |
1696 | break; |
1697 | } |
1698 | |
1699 | return ret; |
1700 | } |
1701 | |
1702 | static struct i915_request * |
1703 | __i915_request_ensure_parallel_ordering(struct i915_request *rq, |
1704 | struct intel_timeline *timeline) |
1705 | { |
1706 | struct i915_request *prev; |
1707 | |
1708 | GEM_BUG_ON(!is_parallel_rq(rq))((void)0); |
1709 | |
1710 | prev = request_to_parent(rq)->parallel.last_rq; |
1711 | if (prev) { |
1712 | if (!__i915_request_is_complete(prev)) { |
1713 | i915_sw_fence_await_sw_fence(&rq->submit, |
1714 | &prev->submit, |
1715 | &rq->submitq); |
1716 | |
1717 | if (rq->engine->sched_engine->schedule) |
1718 | __i915_sched_node_add_dependency(&rq->sched, |
1719 | &prev->sched, |
1720 | &rq->dep, |
1721 | 0); |
1722 | } |
1723 | i915_request_put(prev); |
1724 | } |
1725 | |
1726 | request_to_parent(rq)->parallel.last_rq = i915_request_get(rq); |
1727 | |
1728 | /* |
1729 | * Users have to put a reference potentially got by |
1730 | * __i915_active_fence_set() to the returned request |
1731 | * when no longer needed |
1732 | */ |
1733 | return to_request(__i915_active_fence_set(&timeline->last_request, |
1734 | &rq->fence)); |
1735 | } |
1736 | |
1737 | static struct i915_request * |
1738 | __i915_request_ensure_ordering(struct i915_request *rq, |
1739 | struct intel_timeline *timeline) |
1740 | { |
1741 | struct i915_request *prev; |
1742 | |
1743 | GEM_BUG_ON(is_parallel_rq(rq))((void)0); |
1744 | |
1745 | prev = to_request(__i915_active_fence_set(&timeline->last_request, |
1746 | &rq->fence)); |
1747 | |
1748 | if (prev && !__i915_request_is_complete(prev)) { |
1749 | bool_Bool uses_guc = intel_engine_uses_guc(rq->engine); |
1750 | bool_Bool pow2 = is_power_of_2(READ_ONCE(prev->engine)->mask |(((({ typeof(prev->engine) __tmp = *(volatile typeof(prev-> engine) *)&(prev->engine); membar_datadep_consumer(); __tmp ; })->mask | rq->engine->mask) != 0) && (((( { typeof(prev->engine) __tmp = *(volatile typeof(prev-> engine) *)&(prev->engine); membar_datadep_consumer(); __tmp ; })->mask | rq->engine->mask) - 1) & (({ typeof (prev->engine) __tmp = *(volatile typeof(prev->engine) * )&(prev->engine); membar_datadep_consumer(); __tmp; }) ->mask | rq->engine->mask)) == 0) |
1751 | rq->engine->mask)(((({ typeof(prev->engine) __tmp = *(volatile typeof(prev-> engine) *)&(prev->engine); membar_datadep_consumer(); __tmp ; })->mask | rq->engine->mask) != 0) && (((( { typeof(prev->engine) __tmp = *(volatile typeof(prev-> engine) *)&(prev->engine); membar_datadep_consumer(); __tmp ; })->mask | rq->engine->mask) - 1) & (({ typeof (prev->engine) __tmp = *(volatile typeof(prev->engine) * )&(prev->engine); membar_datadep_consumer(); __tmp; }) ->mask | rq->engine->mask)) == 0); |
1752 | bool_Bool same_context = prev->context == rq->context; |
1753 | |
1754 | /* |
1755 | * The requests are supposed to be kept in order. However, |
1756 | * we need to be wary in case the timeline->last_request |
1757 | * is used as a barrier for external modification to this |
1758 | * context. |
1759 | */ |
1760 | GEM_BUG_ON(same_context &&((void)0) |
1761 | i915_seqno_passed(prev->fence.seqno,((void)0) |
1762 | rq->fence.seqno))((void)0); |
1763 | |
1764 | if ((same_context && uses_guc) || (!uses_guc && pow2)) |
1765 | i915_sw_fence_await_sw_fence(&rq->submit, |
1766 | &prev->submit, |
1767 | &rq->submitq); |
1768 | else |
1769 | __i915_sw_fence_await_dma_fence(&rq->submit, |
1770 | &prev->fence, |
1771 | &rq->dmaq); |
1772 | if (rq->engine->sched_engine->schedule) |
1773 | __i915_sched_node_add_dependency(&rq->sched, |
1774 | &prev->sched, |
1775 | &rq->dep, |
1776 | 0); |
1777 | } |
1778 | |
1779 | /* |
1780 | * Users have to put the reference to prev potentially got |
1781 | * by __i915_active_fence_set() when no longer needed |
1782 | */ |
1783 | return prev; |
1784 | } |
1785 | |
1786 | static struct i915_request * |
1787 | __i915_request_add_to_timeline(struct i915_request *rq) |
1788 | { |
1789 | struct intel_timeline *timeline = i915_request_timeline(rq); |
1790 | struct i915_request *prev; |
1791 | |
1792 | /* |
1793 | * Dependency tracking and request ordering along the timeline |
1794 | * is special cased so that we can eliminate redundant ordering |
1795 | * operations while building the request (we know that the timeline |
1796 | * itself is ordered, and here we guarantee it). |
1797 | * |
1798 | * As we know we will need to emit tracking along the timeline, |
1799 | * we embed the hooks into our request struct -- at the cost of |
1800 | * having to have specialised no-allocation interfaces (which will |
1801 | * be beneficial elsewhere). |
1802 | * |
1803 | * A second benefit to open-coding i915_request_await_request is |
1804 | * that we can apply a slight variant of the rules specialised |
1805 | * for timelines that jump between engines (such as virtual engines). |
1806 | * If we consider the case of virtual engine, we must emit a dma-fence |
1807 | * to prevent scheduling of the second request until the first is |
1808 | * complete (to maximise our greedy late load balancing) and this |
1809 | * precludes optimising to use semaphores serialisation of a single |
1810 | * timeline across engines. |
1811 | * |
1812 | * We do not order parallel submission requests on the timeline as each |
1813 | * parallel submission context has its own timeline and the ordering |
1814 | * rules for parallel requests are that they must be submitted in the |
1815 | * order received from the execbuf IOCTL. So rather than using the |
1816 | * timeline we store a pointer to last request submitted in the |
1817 | * relationship in the gem context and insert a submission fence |
1818 | * between that request and request passed into this function or |
1819 | * alternatively we use completion fence if gem context has a single |
1820 | * timeline and this is the first submission of an execbuf IOCTL. |
1821 | */ |
1822 | if (likely(!is_parallel_rq(rq))__builtin_expect(!!(!is_parallel_rq(rq)), 1)) |
1823 | prev = __i915_request_ensure_ordering(rq, timeline); |
1824 | else |
1825 | prev = __i915_request_ensure_parallel_ordering(rq, timeline); |
1826 | if (prev) |
1827 | i915_request_put(prev); |
1828 | |
1829 | /* |
1830 | * Make sure that no request gazumped us - if it was allocated after |
1831 | * our i915_request_alloc() and called __i915_request_add() before |
1832 | * us, the timeline will hold its seqno which is later than ours. |
1833 | */ |
1834 | GEM_BUG_ON(timeline->seqno != rq->fence.seqno)((void)0); |
1835 | |
1836 | return prev; |
1837 | } |
1838 | |
1839 | /* |
1840 | * NB: This function is not allowed to fail. Doing so would mean the the |
1841 | * request is not being tracked for completion but the work itself is |
1842 | * going to happen on the hardware. This would be a Bad Thing(tm). |
1843 | */ |
1844 | struct i915_request *__i915_request_commit(struct i915_request *rq) |
1845 | { |
1846 | struct intel_engine_cs *engine = rq->engine; |
1847 | struct intel_ring *ring = rq->ring; |
Value stored to 'ring' during its initialization is never read | |
1848 | u32 *cs; |
1849 | |
1850 | RQ_TRACE(rq, "\n")do { const struct i915_request *rq__ = (rq); do { const struct intel_engine_cs *e__ __attribute__((__unused__)) = (rq__-> engine); do { } while (0); } while (0); } while (0); |
1851 | |
1852 | /* |
1853 | * To ensure that this call will not fail, space for its emissions |
1854 | * should already have been reserved in the ring buffer. Let the ring |
1855 | * know that it is time to use that space up. |
1856 | */ |
1857 | GEM_BUG_ON(rq->reserved_space > ring->space)((void)0); |
1858 | rq->reserved_space = 0; |
1859 | rq->emitted_jiffies = jiffies; |
1860 | |
1861 | /* |
1862 | * Record the position of the start of the breadcrumb so that |
1863 | * should we detect the updated seqno part-way through the |
1864 | * GPU processing the request, we never over-estimate the |
1865 | * position of the ring's HEAD. |
1866 | */ |
1867 | cs = intel_ring_begin(rq, engine->emit_fini_breadcrumb_dw); |
1868 | GEM_BUG_ON(IS_ERR(cs))((void)0); |
1869 | rq->postfix = intel_ring_offset(rq, cs); |
1870 | |
1871 | return __i915_request_add_to_timeline(rq); |
1872 | } |
1873 | |
1874 | void __i915_request_queue_bh(struct i915_request *rq) |
1875 | { |
1876 | i915_sw_fence_commit(&rq->semaphore); |
1877 | i915_sw_fence_commit(&rq->submit); |
1878 | } |
1879 | |
1880 | void __i915_request_queue(struct i915_request *rq, |
1881 | const struct i915_sched_attr *attr) |
1882 | { |
1883 | /* |
1884 | * Let the backend know a new request has arrived that may need |
1885 | * to adjust the existing execution schedule due to a high priority |
1886 | * request - i.e. we may want to preempt the current request in order |
1887 | * to run a high priority dependency chain *before* we can execute this |
1888 | * request. |
1889 | * |
1890 | * This is called before the request is ready to run so that we can |
1891 | * decide whether to preempt the entire chain so that it is ready to |
1892 | * run at the earliest possible convenience. |
1893 | */ |
1894 | if (attr && rq->engine->sched_engine->schedule) |
1895 | rq->engine->sched_engine->schedule(rq, attr); |
1896 | |
1897 | local_bh_disable(); |
1898 | __i915_request_queue_bh(rq); |
1899 | local_bh_enable(); /* kick tasklets */ |
1900 | } |
1901 | |
1902 | void i915_request_add(struct i915_request *rq) |
1903 | { |
1904 | struct intel_timeline * const tl = i915_request_timeline(rq); |
1905 | struct i915_sched_attr attr = {}; |
1906 | struct i915_gem_context *ctx; |
1907 | |
1908 | lockdep_assert_held(&tl->mutex)do { (void)(&tl->mutex); } while(0); |
1909 | lockdep_unpin_lock(&tl->mutex, rq->cookie); |
1910 | |
1911 | trace_i915_request_add(rq); |
1912 | __i915_request_commit(rq); |
1913 | |
1914 | /* XXX placeholder for selftests */ |
1915 | rcu_read_lock(); |
1916 | ctx = rcu_dereference(rq->context->gem_context)(rq->context->gem_context); |
1917 | if (ctx) |
1918 | attr = ctx->sched; |
1919 | rcu_read_unlock(); |
1920 | |
1921 | __i915_request_queue(rq, &attr); |
1922 | |
1923 | mutex_unlock(&tl->mutex)rw_exit_write(&tl->mutex); |
1924 | } |
1925 | |
1926 | static unsigned long local_clock_ns(unsigned int *cpu) |
1927 | { |
1928 | unsigned long t; |
1929 | |
1930 | /* |
1931 | * Cheaply and approximately convert from nanoseconds to microseconds. |
1932 | * The result and subsequent calculations are also defined in the same |
1933 | * approximate microseconds units. The principal source of timing |
1934 | * error here is from the simple truncation. |
1935 | * |
1936 | * Note that local_clock() is only defined wrt to the current CPU; |
1937 | * the comparisons are no longer valid if we switch CPUs. Instead of |
1938 | * blocking preemption for the entire busywait, we can detect the CPU |
1939 | * switch and use that as indicator of system load and a reason to |
1940 | * stop busywaiting, see busywait_stop(). |
1941 | */ |
1942 | *cpu = get_cpu()(({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_cpuid); |
1943 | t = local_clock(); |
1944 | put_cpu(); |
1945 | |
1946 | return t; |
1947 | } |
1948 | |
1949 | static bool_Bool busywait_stop(unsigned long timeout, unsigned int cpu) |
1950 | { |
1951 | unsigned int this_cpu; |
1952 | |
1953 | if (time_after(local_clock_ns(&this_cpu), timeout)) |
1954 | return true1; |
1955 | |
1956 | return this_cpu != cpu; |
1957 | } |
1958 | |
1959 | static bool_Bool __i915_spin_request(struct i915_request * const rq, int state) |
1960 | { |
1961 | unsigned long timeout_ns; |
1962 | unsigned int cpu; |
1963 | |
1964 | /* |
1965 | * Only wait for the request if we know it is likely to complete. |
1966 | * |
1967 | * We don't track the timestamps around requests, nor the average |
1968 | * request length, so we do not have a good indicator that this |
1969 | * request will complete within the timeout. What we do know is the |
1970 | * order in which requests are executed by the context and so we can |
1971 | * tell if the request has been started. If the request is not even |
1972 | * running yet, it is a fair assumption that it will not complete |
1973 | * within our relatively short timeout. |
1974 | */ |
1975 | if (!i915_request_is_running(rq)) |
1976 | return false0; |
1977 | |
1978 | /* |
1979 | * When waiting for high frequency requests, e.g. during synchronous |
1980 | * rendering split between the CPU and GPU, the finite amount of time |
1981 | * required to set up the irq and wait upon it limits the response |
1982 | * rate. By busywaiting on the request completion for a short while we |
1983 | * can service the high frequency waits as quick as possible. However, |
1984 | * if it is a slow request, we want to sleep as quickly as possible. |
1985 | * The tradeoff between waiting and sleeping is roughly the time it |
1986 | * takes to sleep on a request, on the order of a microsecond. |
1987 | */ |
1988 | |
1989 | timeout_ns = READ_ONCE(rq->engine->props.max_busywait_duration_ns)({ typeof(rq->engine->props.max_busywait_duration_ns) __tmp = *(volatile typeof(rq->engine->props.max_busywait_duration_ns ) *)&(rq->engine->props.max_busywait_duration_ns); membar_datadep_consumer (); __tmp; }); |
1990 | timeout_ns += local_clock_ns(&cpu); |
1991 | do { |
1992 | if (dma_fence_is_signaled(&rq->fence)) |
1993 | return true1; |
1994 | |
1995 | if (signal_pending_state(state, current)((state) & 0x100 ? (((({struct cpu_info *__ci; asm volatile ("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_siglist | (({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_p->ps_siglist) & ~(({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci ) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci; })->ci_curproc)->p_sigmask) : 0)) |
1996 | break; |
1997 | |
1998 | if (busywait_stop(timeout_ns, cpu)) |
1999 | break; |
2000 | |
2001 | cpu_relax(); |
2002 | } while (!drm_need_resched()(({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_schedstate.spc_schedflags & 0x0002)); |
2003 | |
2004 | return false0; |
2005 | } |
2006 | |
2007 | struct request_wait { |
2008 | struct dma_fence_cb cb; |
2009 | #ifdef __linux__ |
2010 | struct task_struct *tsk; |
2011 | #else |
2012 | struct proc *tsk; |
2013 | #endif |
2014 | }; |
2015 | |
2016 | static void request_wait_wake(struct dma_fence *fence, struct dma_fence_cb *cb) |
2017 | { |
2018 | struct request_wait *wait = container_of(cb, typeof(*wait), cb)({ const __typeof( ((typeof(*wait) *)0)->cb ) *__mptr = (cb ); (typeof(*wait) *)( (char *)__mptr - __builtin_offsetof(typeof (*wait), cb) );}); |
2019 | |
2020 | wake_up_process(fetch_and_zero(&wait->tsk)({ typeof(*&wait->tsk) __T = *(&wait->tsk); *(& wait->tsk) = (typeof(*&wait->tsk))0; __T; })); |
2021 | } |
2022 | |
2023 | /** |
2024 | * i915_request_wait_timeout - wait until execution of request has finished |
2025 | * @rq: the request to wait upon |
2026 | * @flags: how to wait |
2027 | * @timeout: how long to wait in jiffies |
2028 | * |
2029 | * i915_request_wait_timeout() waits for the request to be completed, for a |
2030 | * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an |
2031 | * unbounded wait). |
2032 | * |
2033 | * Returns the remaining time (in jiffies) if the request completed, which may |
2034 | * be zero if the request is unfinished after the timeout expires. |
2035 | * If the timeout is 0, it will return 1 if the fence is signaled. |
2036 | * |
2037 | * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is |
2038 | * pending before the request completes. |
2039 | * |
2040 | * NOTE: This function has the same wait semantics as dma-fence. |
2041 | */ |
2042 | long i915_request_wait_timeout(struct i915_request *rq, |
2043 | unsigned int flags, |
2044 | long timeout) |
2045 | { |
2046 | const int state = flags & I915_WAIT_INTERRUPTIBLE(1UL << (0)) ? |
2047 | TASK_INTERRUPTIBLE0x100 : TASK_UNINTERRUPTIBLE0; |
2048 | struct request_wait wait; |
2049 | |
2050 | might_sleep()assertwaitok(); |
2051 | GEM_BUG_ON(timeout < 0)((void)0); |
2052 | |
2053 | if (dma_fence_is_signaled(&rq->fence)) |
2054 | return timeout ?: 1; |
2055 | |
2056 | if (!timeout) |
2057 | return -ETIME60; |
2058 | |
2059 | trace_i915_request_wait_begin(rq, flags); |
2060 | |
2061 | /* |
2062 | * We must never wait on the GPU while holding a lock as we |
2063 | * may need to perform a GPU reset. So while we don't need to |
2064 | * serialise wait/reset with an explicit lock, we do want |
2065 | * lockdep to detect potential dependency cycles. |
2066 | */ |
2067 | mutex_acquire(&rq->engine->gt->reset.mutex.dep_map, 0, 0, _THIS_IP_); |
2068 | |
2069 | /* |
2070 | * Optimistic spin before touching IRQs. |
2071 | * |
2072 | * We may use a rather large value here to offset the penalty of |
2073 | * switching away from the active task. Frequently, the client will |
2074 | * wait upon an old swapbuffer to throttle itself to remain within a |
2075 | * frame of the gpu. If the client is running in lockstep with the gpu, |
2076 | * then it should not be waiting long at all, and a sleep now will incur |
2077 | * extra scheduler latency in producing the next frame. To try to |
2078 | * avoid adding the cost of enabling/disabling the interrupt to the |
2079 | * short wait, we first spin to see if the request would have completed |
2080 | * in the time taken to setup the interrupt. |
2081 | * |
2082 | * We need upto 5us to enable the irq, and upto 20us to hide the |
2083 | * scheduler latency of a context switch, ignoring the secondary |
2084 | * impacts from a context switch such as cache eviction. |
2085 | * |
2086 | * The scheme used for low-latency IO is called "hybrid interrupt |
2087 | * polling". The suggestion there is to sleep until just before you |
2088 | * expect to be woken by the device interrupt and then poll for its |
2089 | * completion. That requires having a good predictor for the request |
2090 | * duration, which we currently lack. |
2091 | */ |
2092 | if (CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT8000 && |
2093 | __i915_spin_request(rq, state)) |
2094 | goto out; |
2095 | |
2096 | /* |
2097 | * This client is about to stall waiting for the GPU. In many cases |
2098 | * this is undesirable and limits the throughput of the system, as |
2099 | * many clients cannot continue processing user input/output whilst |
2100 | * blocked. RPS autotuning may take tens of milliseconds to respond |
2101 | * to the GPU load and thus incurs additional latency for the client. |
2102 | * We can circumvent that by promoting the GPU frequency to maximum |
2103 | * before we sleep. This makes the GPU throttle up much more quickly |
2104 | * (good for benchmarks and user experience, e.g. window animations), |
2105 | * but at a cost of spending more power processing the workload |
2106 | * (bad for battery). |
2107 | */ |
2108 | if (flags & I915_WAIT_PRIORITY(1UL << (1)) && !i915_request_started(rq)) |
2109 | intel_rps_boost(rq); |
2110 | |
2111 | #ifdef __linux__ |
2112 | wait.tsk = current; |
2113 | #else |
2114 | wait.tsk = curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc; |
2115 | #endif |
2116 | if (dma_fence_add_callback(&rq->fence, &wait.cb, request_wait_wake)) |
2117 | goto out; |
2118 | |
2119 | /* |
2120 | * Flush the submission tasklet, but only if it may help this request. |
2121 | * |
2122 | * We sometimes experience some latency between the HW interrupts and |
2123 | * tasklet execution (mostly due to ksoftirqd latency, but it can also |
2124 | * be due to lazy CS events), so lets run the tasklet manually if there |
2125 | * is a chance it may submit this request. If the request is not ready |
2126 | * to run, as it is waiting for other fences to be signaled, flushing |
2127 | * the tasklet is busy work without any advantage for this client. |
2128 | * |
2129 | * If the HW is being lazy, this is the last chance before we go to |
2130 | * sleep to catch any pending events. We will check periodically in |
2131 | * the heartbeat to flush the submission tasklets as a last resort |
2132 | * for unhappy HW. |
2133 | */ |
2134 | if (i915_request_is_ready(rq)) |
2135 | __intel_engine_flush_submission(rq->engine, false0); |
2136 | |
2137 | for (;;) { |
2138 | set_current_state(state); |
2139 | |
2140 | if (dma_fence_is_signaled(&rq->fence)) |
2141 | break; |
2142 | |
2143 | if (signal_pending_state(state, current)((state) & 0x100 ? (((({struct cpu_info *__ci; asm volatile ("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_siglist | (({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_p->ps_siglist) & ~(({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci ) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci; })->ci_curproc)->p_sigmask) : 0)) { |
2144 | timeout = -ERESTARTSYS4; |
2145 | break; |
2146 | } |
2147 | |
2148 | if (!timeout) { |
2149 | timeout = -ETIME60; |
2150 | break; |
2151 | } |
2152 | |
2153 | timeout = io_schedule_timeout(timeout)schedule_timeout(timeout); |
2154 | } |
2155 | __set_current_state(TASK_RUNNING-1); |
2156 | |
2157 | if (READ_ONCE(wait.tsk)({ typeof(wait.tsk) __tmp = *(volatile typeof(wait.tsk) *)& (wait.tsk); membar_datadep_consumer(); __tmp; })) |
2158 | dma_fence_remove_callback(&rq->fence, &wait.cb); |
2159 | GEM_BUG_ON(!list_empty(&wait.cb.node))((void)0); |
2160 | |
2161 | out: |
2162 | mutex_release(&rq->engine->gt->reset.mutex.dep_map, _THIS_IP_); |
2163 | trace_i915_request_wait_end(rq); |
2164 | return timeout; |
2165 | } |
2166 | |
2167 | /** |
2168 | * i915_request_wait - wait until execution of request has finished |
2169 | * @rq: the request to wait upon |
2170 | * @flags: how to wait |
2171 | * @timeout: how long to wait in jiffies |
2172 | * |
2173 | * i915_request_wait() waits for the request to be completed, for a |
2174 | * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an |
2175 | * unbounded wait). |
2176 | * |
2177 | * Returns the remaining time (in jiffies) if the request completed, which may |
2178 | * be zero or -ETIME if the request is unfinished after the timeout expires. |
2179 | * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is |
2180 | * pending before the request completes. |
2181 | * |
2182 | * NOTE: This function behaves differently from dma-fence wait semantics for |
2183 | * timeout = 0. It returns 0 on success, and -ETIME if not signaled. |
2184 | */ |
2185 | long i915_request_wait(struct i915_request *rq, |
2186 | unsigned int flags, |
2187 | long timeout) |
2188 | { |
2189 | long ret = i915_request_wait_timeout(rq, flags, timeout); |
2190 | |
2191 | if (!ret) |
2192 | return -ETIME60; |
2193 | |
2194 | if (ret > 0 && !timeout) |
2195 | return 0; |
2196 | |
2197 | return ret; |
2198 | } |
2199 | |
2200 | static int print_sched_attr(const struct i915_sched_attr *attr, |
2201 | char *buf, int x, int len) |
2202 | { |
2203 | if (attr->priority == I915_PRIORITY_INVALID((-0x7fffffff-1))) |
2204 | return x; |
2205 | |
2206 | x += snprintf(buf + x, len - x, |
2207 | " prio=%d", attr->priority); |
2208 | |
2209 | return x; |
2210 | } |
2211 | |
2212 | static char queue_status(const struct i915_request *rq) |
2213 | { |
2214 | if (i915_request_is_active(rq)) |
2215 | return 'E'; |
2216 | |
2217 | if (i915_request_is_ready(rq)) |
2218 | return intel_engine_is_virtual(rq->engine) ? 'V' : 'R'; |
2219 | |
2220 | return 'U'; |
2221 | } |
2222 | |
2223 | static const char *run_status(const struct i915_request *rq) |
2224 | { |
2225 | if (__i915_request_is_complete(rq)) |
2226 | return "!"; |
2227 | |
2228 | if (__i915_request_has_started(rq)) |
2229 | return "*"; |
2230 | |
2231 | if (!i915_sw_fence_signaled(&rq->semaphore)) |
2232 | return "&"; |
2233 | |
2234 | return ""; |
2235 | } |
2236 | |
2237 | static const char *fence_status(const struct i915_request *rq) |
2238 | { |
2239 | if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags)) |
2240 | return "+"; |
2241 | |
2242 | if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags)) |
2243 | return "-"; |
2244 | |
2245 | return ""; |
2246 | } |
2247 | |
2248 | void i915_request_show(struct drm_printer *m, |
2249 | const struct i915_request *rq, |
2250 | const char *prefix, |
2251 | int indent) |
2252 | { |
2253 | const char *name = rq->fence.ops->get_timeline_name((struct dma_fence *)&rq->fence); |
2254 | char buf[80] = ""; |
2255 | int x = 0; |
2256 | |
2257 | /* |
2258 | * The prefix is used to show the queue status, for which we use |
2259 | * the following flags: |
2260 | * |
2261 | * U [Unready] |
2262 | * - initial status upon being submitted by the user |
2263 | * |
2264 | * - the request is not ready for execution as it is waiting |
2265 | * for external fences |
2266 | * |
2267 | * R [Ready] |
2268 | * - all fences the request was waiting on have been signaled, |
2269 | * and the request is now ready for execution and will be |
2270 | * in a backend queue |
2271 | * |
2272 | * - a ready request may still need to wait on semaphores |
2273 | * [internal fences] |
2274 | * |
2275 | * V [Ready/virtual] |
2276 | * - same as ready, but queued over multiple backends |
2277 | * |
2278 | * E [Executing] |
2279 | * - the request has been transferred from the backend queue and |
2280 | * submitted for execution on HW |
2281 | * |
2282 | * - a completed request may still be regarded as executing, its |
2283 | * status may not be updated until it is retired and removed |
2284 | * from the lists |
2285 | */ |
2286 | |
2287 | x = print_sched_attr(&rq->sched.attr, buf, x, sizeof(buf)); |
2288 | |
2289 | drm_printf(m, "%s%.*s%c %llx:%lld%s%s %s @ %dms: %s\n", |
2290 | prefix, indent, " ", |
2291 | queue_status(rq), |
2292 | rq->fence.context, rq->fence.seqno, |
2293 | run_status(rq), |
2294 | fence_status(rq), |
2295 | buf, |
2296 | jiffies_to_msecs(jiffies - rq->emitted_jiffies), |
2297 | name); |
2298 | } |
2299 | |
2300 | static bool_Bool engine_match_ring(struct intel_engine_cs *engine, struct i915_request *rq) |
2301 | { |
2302 | u32 ring = ENGINE_READ(engine, RING_START)intel_uncore_read(((engine))->uncore, ((const i915_reg_t){ .reg = (((engine)->mmio_base) + 0x38) })); |
2303 | |
2304 | return ring == i915_ggtt_offset(rq->ring->vma); |
2305 | } |
2306 | |
2307 | static bool_Bool match_ring(struct i915_request *rq) |
2308 | { |
2309 | struct intel_engine_cs *engine; |
2310 | bool_Bool found; |
2311 | int i; |
2312 | |
2313 | if (!intel_engine_is_virtual(rq->engine)) |
2314 | return engine_match_ring(rq->engine, rq); |
2315 | |
2316 | found = false0; |
2317 | i = 0; |
2318 | while ((engine = intel_engine_get_sibling(rq->engine, i++))) { |
2319 | found = engine_match_ring(engine, rq); |
2320 | if (found) |
2321 | break; |
2322 | } |
2323 | |
2324 | return found; |
2325 | } |
2326 | |
2327 | enum i915_request_state i915_test_request_state(struct i915_request *rq) |
2328 | { |
2329 | if (i915_request_completed(rq)) |
2330 | return I915_REQUEST_COMPLETE; |
2331 | |
2332 | if (!i915_request_started(rq)) |
2333 | return I915_REQUEST_PENDING; |
2334 | |
2335 | if (match_ring(rq)) |
2336 | return I915_REQUEST_ACTIVE; |
2337 | |
2338 | return I915_REQUEST_QUEUED; |
2339 | } |
2340 | |
2341 | #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)0 |
2342 | #include "selftests/mock_request.c" |
2343 | #include "selftests/i915_request.c" |
2344 | #endif |
2345 | |
2346 | void i915_request_module_exit(void) |
2347 | { |
2348 | #ifdef __linux__ |
2349 | kmem_cache_destroy(slab_execute_cbs); |
2350 | kmem_cache_destroy(slab_requests); |
2351 | #else |
2352 | pool_destroy(&slab_execute_cbs); |
2353 | pool_destroy(&slab_requests); |
2354 | #endif |
2355 | } |
2356 | |
2357 | int __init i915_request_module_init(void) |
2358 | { |
2359 | #ifdef __linux__ |
2360 | slab_requests = |
2361 | kmem_cache_create("i915_request", |
2362 | sizeof(struct i915_request), |
2363 | __alignof__(struct i915_request), |
2364 | SLAB_HWCACHE_ALIGN | |
2365 | SLAB_RECLAIM_ACCOUNT | |
2366 | SLAB_TYPESAFE_BY_RCU, |
2367 | __i915_request_ctor); |
2368 | if (!slab_requests) |
2369 | return -ENOMEM12; |
2370 | |
2371 | slab_execute_cbs = KMEM_CACHE(execute_cb, |
2372 | SLAB_HWCACHE_ALIGN | |
2373 | SLAB_RECLAIM_ACCOUNT | |
2374 | SLAB_TYPESAFE_BY_RCU); |
2375 | if (!slab_execute_cbs) |
2376 | goto err_requests; |
2377 | #else |
2378 | pool_init(&slab_requests, sizeof(struct i915_request), |
2379 | CACHELINESIZE64, IPL_TTY0x9, 0, "i915_request", NULL((void *)0)); |
2380 | pool_init(&slab_execute_cbs, sizeof(struct execute_cb), |
2381 | CACHELINESIZE64, IPL_TTY0x9, 0, "i915_exec", NULL((void *)0)); |
2382 | #endif |
2383 | |
2384 | return 0; |
2385 | |
2386 | #ifdef __linux__ |
2387 | err_requests: |
2388 | kmem_cache_destroy(slab_requests); |
2389 | return -ENOMEM12; |
2390 | #endif |
2391 | } |