2 * Copyright © 2014 Intel Corporation
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
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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:
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
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
24 * Ben Widawsky <ben@bwidawsk.net>
25 * Michel Thierry <michel.thierry@intel.com>
26 * Thomas Daniel <thomas.daniel@intel.com>
27 * Oscar Mateo <oscar.mateo@intel.com>
32 * DOC: Logical Rings, Logical Ring Contexts and Execlists
35 * GEN8 brings an expansion of the HW contexts: "Logical Ring Contexts".
36 * These expanded contexts enable a number of new abilities, especially
37 * "Execlists" (also implemented in this file).
39 * One of the main differences with the legacy HW contexts is that logical
40 * ring contexts incorporate many more things to the context's state, like
41 * PDPs or ringbuffer control registers:
43 * The reason why PDPs are included in the context is straightforward: as
44 * PPGTTs (per-process GTTs) are actually per-context, having the PDPs
45 * contained there mean you don't need to do a ppgtt->switch_mm yourself,
46 * instead, the GPU will do it for you on the context switch.
48 * But, what about the ringbuffer control registers (head, tail, etc..)?
49 * shouldn't we just need a set of those per engine command streamer? This is
50 * where the name "Logical Rings" starts to make sense: by virtualizing the
51 * rings, the engine cs shifts to a new "ring buffer" with every context
52 * switch. When you want to submit a workload to the GPU you: A) choose your
53 * context, B) find its appropriate virtualized ring, C) write commands to it
54 * and then, finally, D) tell the GPU to switch to that context.
56 * Instead of the legacy MI_SET_CONTEXT, the way you tell the GPU to switch
57 * to a contexts is via a context execution list, ergo "Execlists".
60 * Regarding the creation of contexts, we have:
62 * - One global default context.
63 * - One local default context for each opened fd.
64 * - One local extra context for each context create ioctl call.
66 * Now that ringbuffers belong per-context (and not per-engine, like before)
67 * and that contexts are uniquely tied to a given engine (and not reusable,
68 * like before) we need:
70 * - One ringbuffer per-engine inside each context.
71 * - One backing object per-engine inside each context.
73 * The global default context starts its life with these new objects fully
74 * allocated and populated. The local default context for each opened fd is
75 * more complex, because we don't know at creation time which engine is going
76 * to use them. To handle this, we have implemented a deferred creation of LR
79 * The local context starts its life as a hollow or blank holder, that only
80 * gets populated for a given engine once we receive an execbuffer. If later
81 * on we receive another execbuffer ioctl for the same context but a different
82 * engine, we allocate/populate a new ringbuffer and context backing object and
85 * Finally, regarding local contexts created using the ioctl call: as they are
86 * only allowed with the render ring, we can allocate & populate them right
87 * away (no need to defer anything, at least for now).
89 * Execlists implementation:
90 * Execlists are the new method by which, on gen8+ hardware, workloads are
91 * submitted for execution (as opposed to the legacy, ringbuffer-based, method).
92 * This method works as follows:
94 * When a request is committed, its commands (the BB start and any leading or
95 * trailing commands, like the seqno breadcrumbs) are placed in the ringbuffer
96 * for the appropriate context. The tail pointer in the hardware context is not
97 * updated at this time, but instead, kept by the driver in the ringbuffer
98 * structure. A structure representing this request is added to a request queue
99 * for the appropriate engine: this structure contains a copy of the context's
100 * tail after the request was written to the ring buffer and a pointer to the
103 * If the engine's request queue was empty before the request was added, the
104 * queue is processed immediately. Otherwise the queue will be processed during
105 * a context switch interrupt. In any case, elements on the queue will get sent
106 * (in pairs) to the GPU's ExecLists Submit Port (ELSP, for short) with a
107 * globally unique 20-bits submission ID.
109 * When execution of a request completes, the GPU updates the context status
110 * buffer with a context complete event and generates a context switch interrupt.
111 * During the interrupt handling, the driver examines the events in the buffer:
112 * for each context complete event, if the announced ID matches that on the head
113 * of the request queue, then that request is retired and removed from the queue.
115 * After processing, if any requests were retired and the queue is not empty
116 * then a new execution list can be submitted. The two requests at the front of
117 * the queue are next to be submitted but since a context may not occur twice in
118 * an execution list, if subsequent requests have the same ID as the first then
119 * the two requests must be combined. This is done simply by discarding requests
120 * at the head of the queue until either only one requests is left (in which case
121 * we use a NULL second context) or the first two requests have unique IDs.
123 * By always executing the first two requests in the queue the driver ensures
124 * that the GPU is kept as busy as possible. In the case where a single context
125 * completes but a second context is still executing, the request for this second
126 * context will be at the head of the queue when we remove the first one. This
127 * request will then be resubmitted along with a new request for a different context,
128 * which will cause the hardware to continue executing the second request and queue
129 * the new request (the GPU detects the condition of a context getting preempted
130 * with the same context and optimizes the context switch flow by not doing
131 * preemption, but just sampling the new tail pointer).
134 #include <linux/interrupt.h>
136 #include "i915_drv.h"
137 #include "i915_perf.h"
138 #include "i915_trace.h"
139 #include "i915_vgpu.h"
140 #include "intel_context.h"
141 #include "intel_engine_pm.h"
142 #include "intel_gt.h"
143 #include "intel_gt_pm.h"
144 #include "intel_gt_requests.h"
145 #include "intel_lrc_reg.h"
146 #include "intel_mocs.h"
147 #include "intel_reset.h"
148 #include "intel_ring.h"
149 #include "intel_workarounds.h"
151 #define RING_EXECLIST_QFULL (1 << 0x2)
152 #define RING_EXECLIST1_VALID (1 << 0x3)
153 #define RING_EXECLIST0_VALID (1 << 0x4)
154 #define RING_EXECLIST_ACTIVE_STATUS (3 << 0xE)
155 #define RING_EXECLIST1_ACTIVE (1 << 0x11)
156 #define RING_EXECLIST0_ACTIVE (1 << 0x12)
158 #define GEN8_CTX_STATUS_IDLE_ACTIVE (1 << 0)
159 #define GEN8_CTX_STATUS_PREEMPTED (1 << 1)
160 #define GEN8_CTX_STATUS_ELEMENT_SWITCH (1 << 2)
161 #define GEN8_CTX_STATUS_ACTIVE_IDLE (1 << 3)
162 #define GEN8_CTX_STATUS_COMPLETE (1 << 4)
163 #define GEN8_CTX_STATUS_LITE_RESTORE (1 << 15)
165 #define GEN8_CTX_STATUS_COMPLETED_MASK \
166 (GEN8_CTX_STATUS_COMPLETE | GEN8_CTX_STATUS_PREEMPTED)
168 #define CTX_DESC_FORCE_RESTORE BIT_ULL(2)
170 #define GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE (0x1) /* lower csb dword */
171 #define GEN12_CTX_SWITCH_DETAIL(csb_dw) ((csb_dw) & 0xF) /* upper csb dword */
172 #define GEN12_CSB_SW_CTX_ID_MASK GENMASK(25, 15)
173 #define GEN12_IDLE_CTX_ID 0x7FF
174 #define GEN12_CSB_CTX_VALID(csb_dw) \
175 (FIELD_GET(GEN12_CSB_SW_CTX_ID_MASK, csb_dw) != GEN12_IDLE_CTX_ID)
177 /* Typical size of the average request (2 pipecontrols and a MI_BB) */
178 #define EXECLISTS_REQUEST_SIZE 64 /* bytes */
180 struct virtual_engine {
181 struct intel_engine_cs base;
182 struct intel_context context;
185 * We allow only a single request through the virtual engine at a time
186 * (each request in the timeline waits for the completion fence of
187 * the previous before being submitted). By restricting ourselves to
188 * only submitting a single request, each request is placed on to a
189 * physical to maximise load spreading (by virtue of the late greedy
190 * scheduling -- each real engine takes the next available request
193 struct i915_request *request;
196 * We keep a rbtree of available virtual engines inside each physical
197 * engine, sorted by priority. Here we preallocate the nodes we need
198 * for the virtual engine, indexed by physical_engine->id.
203 } nodes[I915_NUM_ENGINES];
206 * Keep track of bonded pairs -- restrictions upon on our selection
207 * of physical engines any particular request may be submitted to.
208 * If we receive a submit-fence from a master engine, we will only
209 * use one of sibling_mask physical engines.
212 const struct intel_engine_cs *master;
213 intel_engine_mask_t sibling_mask;
215 unsigned int num_bonds;
217 /* And finally, which physical engines this virtual engine maps onto. */
218 unsigned int num_siblings;
219 struct intel_engine_cs *siblings[0];
222 static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
224 GEM_BUG_ON(!intel_engine_is_virtual(engine));
225 return container_of(engine, struct virtual_engine, base);
228 static int __execlists_context_alloc(struct intel_context *ce,
229 struct intel_engine_cs *engine);
231 static void execlists_init_reg_state(u32 *reg_state,
232 const struct intel_context *ce,
233 const struct intel_engine_cs *engine,
234 const struct intel_ring *ring,
237 __execlists_update_reg_state(const struct intel_context *ce,
238 const struct intel_engine_cs *engine,
241 static void mark_eio(struct i915_request *rq)
243 if (i915_request_completed(rq))
246 GEM_BUG_ON(i915_request_signaled(rq));
248 i915_request_set_error_once(rq, -EIO);
249 i915_request_mark_complete(rq);
252 static struct i915_request *
253 active_request(const struct intel_timeline * const tl, struct i915_request *rq)
255 struct i915_request *active = rq;
258 list_for_each_entry_continue_reverse(rq, &tl->requests, link) {
259 if (i915_request_completed(rq))
269 static inline u32 intel_hws_preempt_address(struct intel_engine_cs *engine)
271 return (i915_ggtt_offset(engine->status_page.vma) +
272 I915_GEM_HWS_PREEMPT_ADDR);
276 ring_set_paused(const struct intel_engine_cs *engine, int state)
279 * We inspect HWS_PREEMPT with a semaphore inside
280 * engine->emit_fini_breadcrumb. If the dword is true,
281 * the ring is paused as the semaphore will busywait
282 * until the dword is false.
284 engine->status_page.addr[I915_GEM_HWS_PREEMPT] = state;
289 static inline struct i915_priolist *to_priolist(struct rb_node *rb)
291 return rb_entry(rb, struct i915_priolist, node);
294 static inline int rq_prio(const struct i915_request *rq)
296 return READ_ONCE(rq->sched.attr.priority);
299 static int effective_prio(const struct i915_request *rq)
301 int prio = rq_prio(rq);
304 * If this request is special and must not be interrupted at any
305 * cost, so be it. Note we are only checking the most recent request
306 * in the context and so may be masking an earlier vip request. It
307 * is hoped that under the conditions where nopreempt is used, this
308 * will not matter (i.e. all requests to that context will be
309 * nopreempt for as long as desired).
311 if (i915_request_has_nopreempt(rq))
312 prio = I915_PRIORITY_UNPREEMPTABLE;
315 * On unwinding the active request, we give it a priority bump
316 * if it has completed waiting on any semaphore. If we know that
317 * the request has already started, we can prevent an unwanted
318 * preempt-to-idle cycle by taking that into account now.
320 if (__i915_request_has_started(rq))
321 prio |= I915_PRIORITY_NOSEMAPHORE;
323 /* Restrict mere WAIT boosts from triggering preemption */
324 BUILD_BUG_ON(__NO_PREEMPTION & ~I915_PRIORITY_MASK); /* only internal */
325 return prio | __NO_PREEMPTION;
328 static int queue_prio(const struct intel_engine_execlists *execlists)
330 struct i915_priolist *p;
333 rb = rb_first_cached(&execlists->queue);
338 * As the priolist[] are inverted, with the highest priority in [0],
339 * we have to flip the index value to become priority.
342 return ((p->priority + 1) << I915_USER_PRIORITY_SHIFT) - ffs(p->used);
345 static inline bool need_preempt(const struct intel_engine_cs *engine,
346 const struct i915_request *rq,
351 if (!intel_engine_has_semaphores(engine))
355 * Check if the current priority hint merits a preemption attempt.
357 * We record the highest value priority we saw during rescheduling
358 * prior to this dequeue, therefore we know that if it is strictly
359 * less than the current tail of ESLP[0], we do not need to force
360 * a preempt-to-idle cycle.
362 * However, the priority hint is a mere hint that we may need to
363 * preempt. If that hint is stale or we may be trying to preempt
364 * ourselves, ignore the request.
366 * More naturally we would write
367 * prio >= max(0, last);
368 * except that we wish to prevent triggering preemption at the same
369 * priority level: the task that is running should remain running
370 * to preserve FIFO ordering of dependencies.
372 last_prio = max(effective_prio(rq), I915_PRIORITY_NORMAL - 1);
373 if (engine->execlists.queue_priority_hint <= last_prio)
377 * Check against the first request in ELSP[1], it will, thanks to the
378 * power of PI, be the highest priority of that context.
380 if (!list_is_last(&rq->sched.link, &engine->active.requests) &&
381 rq_prio(list_next_entry(rq, sched.link)) > last_prio)
385 struct virtual_engine *ve =
386 rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
387 bool preempt = false;
389 if (engine == ve->siblings[0]) { /* only preempt one sibling */
390 struct i915_request *next;
393 next = READ_ONCE(ve->request);
395 preempt = rq_prio(next) > last_prio;
404 * If the inflight context did not trigger the preemption, then maybe
405 * it was the set of queued requests? Pick the highest priority in
406 * the queue (the first active priolist) and see if it deserves to be
407 * running instead of ELSP[0].
409 * The highest priority request in the queue can not be either
410 * ELSP[0] or ELSP[1] as, thanks again to PI, if it was the same
411 * context, it's priority would not exceed ELSP[0] aka last_prio.
413 return queue_prio(&engine->execlists) > last_prio;
416 __maybe_unused static inline bool
417 assert_priority_queue(const struct i915_request *prev,
418 const struct i915_request *next)
421 * Without preemption, the prev may refer to the still active element
422 * which we refuse to let go.
424 * Even with preemption, there are times when we think it is better not
425 * to preempt and leave an ostensibly lower priority request in flight.
427 if (i915_request_is_active(prev))
430 return rq_prio(prev) >= rq_prio(next);
434 * The context descriptor encodes various attributes of a context,
435 * including its GTT address and some flags. Because it's fairly
436 * expensive to calculate, we'll just do it once and cache the result,
437 * which remains valid until the context is unpinned.
439 * This is what a descriptor looks like, from LSB to MSB::
441 * bits 0-11: flags, GEN8_CTX_* (cached in ctx->desc_template)
442 * bits 12-31: LRCA, GTT address of (the HWSP of) this context
443 * bits 32-52: ctx ID, a globally unique tag (highest bit used by GuC)
444 * bits 53-54: mbz, reserved for use by hardware
445 * bits 55-63: group ID, currently unused and set to 0
447 * Starting from Gen11, the upper dword of the descriptor has a new format:
449 * bits 32-36: reserved
450 * bits 37-47: SW context ID
451 * bits 48:53: engine instance
452 * bit 54: mbz, reserved for use by hardware
453 * bits 55-60: SW counter
454 * bits 61-63: engine class
456 * engine info, SW context ID and SW counter need to form a unique number
457 * (Context ID) per lrc.
460 lrc_descriptor(struct intel_context *ce, struct intel_engine_cs *engine)
464 desc = INTEL_LEGACY_32B_CONTEXT;
465 if (i915_vm_is_4lvl(ce->vm))
466 desc = INTEL_LEGACY_64B_CONTEXT;
467 desc <<= GEN8_CTX_ADDRESSING_MODE_SHIFT;
469 desc |= GEN8_CTX_VALID | GEN8_CTX_PRIVILEGE;
470 if (IS_GEN(engine->i915, 8))
471 desc |= GEN8_CTX_L3LLC_COHERENT;
473 desc |= i915_ggtt_offset(ce->state); /* bits 12-31 */
475 * The following 32bits are copied into the OA reports (dword 2).
476 * Consider updating oa_get_render_ctx_id in i915_perf.c when changing
479 if (INTEL_GEN(engine->i915) >= 11) {
480 desc |= (u64)engine->instance << GEN11_ENGINE_INSTANCE_SHIFT;
483 desc |= (u64)engine->class << GEN11_ENGINE_CLASS_SHIFT;
490 static inline unsigned int dword_in_page(void *addr)
492 return offset_in_page(addr) / sizeof(u32);
495 static void set_offsets(u32 *regs,
497 const struct intel_engine_cs *engine,
499 #define NOP(x) (BIT(7) | (x))
500 #define LRI(count, flags) ((flags) << 6 | (count) | BUILD_BUG_ON_ZERO(count >= BIT(6)))
501 #define POSTED BIT(0)
502 #define REG(x) (((x) >> 2) | BUILD_BUG_ON_ZERO(x >= 0x200))
504 (((x) >> 9) | BIT(7) | BUILD_BUG_ON_ZERO(x >= 0x10000)), \
506 #define END(x) 0, (x)
508 const u32 base = engine->mmio_base;
513 if (*data & BIT(7)) { /* skip */
514 count = *data++ & ~BIT(7);
516 memset32(regs, MI_NOOP, count);
521 count = *data & 0x3f;
525 *regs = MI_LOAD_REGISTER_IMM(count);
527 *regs |= MI_LRI_FORCE_POSTED;
528 if (INTEL_GEN(engine->i915) >= 11)
529 *regs |= MI_LRI_CS_MMIO;
540 offset |= v & ~BIT(7);
541 } while (v & BIT(7));
543 regs[0] = base + (offset << 2);
553 /* Clear past the tail for HW access */
554 GEM_BUG_ON(dword_in_page(regs) > count);
555 memset32(regs, MI_NOOP, count - dword_in_page(regs));
557 /* Close the batch; used mainly by live_lrc_layout() */
558 *regs = MI_BATCH_BUFFER_END;
559 if (INTEL_GEN(engine->i915) >= 10)
564 static const u8 gen8_xcs_offsets[] = {
599 static const u8 gen9_xcs_offsets[] = {
683 static const u8 gen12_xcs_offsets[] = {
715 static const u8 gen8_rcs_offsets[] = {
752 static const u8 gen9_rcs_offsets[] = {
836 static const u8 gen11_rcs_offsets[] = {
877 static const u8 gen12_rcs_offsets[] = {
924 static const u8 *reg_offsets(const struct intel_engine_cs *engine)
927 * The gen12+ lists only have the registers we program in the basic
928 * default state. We rely on the context image using relative
929 * addressing to automatic fixup the register state between the
930 * physical engines for virtual engine.
932 GEM_BUG_ON(INTEL_GEN(engine->i915) >= 12 &&
933 !intel_engine_has_relative_mmio(engine));
935 if (engine->class == RENDER_CLASS) {
936 if (INTEL_GEN(engine->i915) >= 12)
937 return gen12_rcs_offsets;
938 else if (INTEL_GEN(engine->i915) >= 11)
939 return gen11_rcs_offsets;
940 else if (INTEL_GEN(engine->i915) >= 9)
941 return gen9_rcs_offsets;
943 return gen8_rcs_offsets;
945 if (INTEL_GEN(engine->i915) >= 12)
946 return gen12_xcs_offsets;
947 else if (INTEL_GEN(engine->i915) >= 9)
948 return gen9_xcs_offsets;
950 return gen8_xcs_offsets;
954 static struct i915_request *
955 __unwind_incomplete_requests(struct intel_engine_cs *engine)
957 struct i915_request *rq, *rn, *active = NULL;
958 struct list_head *uninitialized_var(pl);
959 int prio = I915_PRIORITY_INVALID;
961 lockdep_assert_held(&engine->active.lock);
963 list_for_each_entry_safe_reverse(rq, rn,
964 &engine->active.requests,
966 if (i915_request_completed(rq))
969 __i915_request_unsubmit(rq);
972 * Push the request back into the queue for later resubmission.
973 * If this request is not native to this physical engine (i.e.
974 * it came from a virtual source), push it back onto the virtual
975 * engine so that it can be moved across onto another physical
976 * engine as load dictates.
978 if (likely(rq->execution_mask == engine->mask)) {
979 GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID);
980 if (rq_prio(rq) != prio) {
982 pl = i915_sched_lookup_priolist(engine, prio);
984 GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
986 list_move(&rq->sched.link, pl);
987 set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
991 struct intel_engine_cs *owner = rq->context->engine;
994 * Decouple the virtual breadcrumb before moving it
995 * back to the virtual engine -- we don't want the
996 * request to complete in the background and try
997 * and cancel the breadcrumb on the virtual engine
998 * (instead of the old engine where it is linked)!
1000 if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
1001 &rq->fence.flags)) {
1002 spin_lock_nested(&rq->lock,
1003 SINGLE_DEPTH_NESTING);
1004 i915_request_cancel_breadcrumb(rq);
1005 spin_unlock(&rq->lock);
1007 WRITE_ONCE(rq->engine, owner);
1008 owner->submit_request(rq);
1016 struct i915_request *
1017 execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists)
1019 struct intel_engine_cs *engine =
1020 container_of(execlists, typeof(*engine), execlists);
1022 return __unwind_incomplete_requests(engine);
1026 execlists_context_status_change(struct i915_request *rq, unsigned long status)
1029 * Only used when GVT-g is enabled now. When GVT-g is disabled,
1030 * The compiler should eliminate this function as dead-code.
1032 if (!IS_ENABLED(CONFIG_DRM_I915_GVT))
1035 atomic_notifier_call_chain(&rq->engine->context_status_notifier,
1039 static void intel_engine_context_in(struct intel_engine_cs *engine)
1041 unsigned long flags;
1043 if (READ_ONCE(engine->stats.enabled) == 0)
1046 write_seqlock_irqsave(&engine->stats.lock, flags);
1048 if (engine->stats.enabled > 0) {
1049 if (engine->stats.active++ == 0)
1050 engine->stats.start = ktime_get();
1051 GEM_BUG_ON(engine->stats.active == 0);
1054 write_sequnlock_irqrestore(&engine->stats.lock, flags);
1057 static void intel_engine_context_out(struct intel_engine_cs *engine)
1059 unsigned long flags;
1061 if (READ_ONCE(engine->stats.enabled) == 0)
1064 write_seqlock_irqsave(&engine->stats.lock, flags);
1066 if (engine->stats.enabled > 0) {
1069 if (engine->stats.active && --engine->stats.active == 0) {
1071 * Decrement the active context count and in case GPU
1072 * is now idle add up to the running total.
1074 last = ktime_sub(ktime_get(), engine->stats.start);
1076 engine->stats.total = ktime_add(engine->stats.total,
1078 } else if (engine->stats.active == 0) {
1080 * After turning on engine stats, context out might be
1081 * the first event in which case we account from the
1082 * time stats gathering was turned on.
1084 last = ktime_sub(ktime_get(), engine->stats.enabled_at);
1086 engine->stats.total = ktime_add(engine->stats.total,
1091 write_sequnlock_irqrestore(&engine->stats.lock, flags);
1094 static int lrc_ring_mi_mode(const struct intel_engine_cs *engine)
1096 if (INTEL_GEN(engine->i915) >= 12)
1098 else if (INTEL_GEN(engine->i915) >= 9)
1100 else if (engine->class == RENDER_CLASS)
1107 execlists_check_context(const struct intel_context *ce,
1108 const struct intel_engine_cs *engine)
1110 const struct intel_ring *ring = ce->ring;
1111 u32 *regs = ce->lrc_reg_state;
1115 if (regs[CTX_RING_START] != i915_ggtt_offset(ring->vma)) {
1116 pr_err("%s: context submitted with incorrect RING_START [%08x], expected %08x\n",
1118 regs[CTX_RING_START],
1119 i915_ggtt_offset(ring->vma));
1120 regs[CTX_RING_START] = i915_ggtt_offset(ring->vma);
1124 if ((regs[CTX_RING_CTL] & ~(RING_WAIT | RING_WAIT_SEMAPHORE)) !=
1125 (RING_CTL_SIZE(ring->size) | RING_VALID)) {
1126 pr_err("%s: context submitted with incorrect RING_CTL [%08x], expected %08x\n",
1129 (u32)(RING_CTL_SIZE(ring->size) | RING_VALID));
1130 regs[CTX_RING_CTL] = RING_CTL_SIZE(ring->size) | RING_VALID;
1134 x = lrc_ring_mi_mode(engine);
1135 if (x != -1 && regs[x + 1] & (regs[x + 1] >> 16) & STOP_RING) {
1136 pr_err("%s: context submitted with STOP_RING [%08x] in RING_MI_MODE\n",
1137 engine->name, regs[x + 1]);
1138 regs[x + 1] &= ~STOP_RING;
1139 regs[x + 1] |= STOP_RING << 16;
1143 WARN_ONCE(!valid, "Invalid lrc state found before submission\n");
1146 static void restore_default_state(struct intel_context *ce,
1147 struct intel_engine_cs *engine)
1149 u32 *regs = ce->lrc_reg_state;
1151 if (engine->pinned_default_state)
1152 memcpy(regs, /* skip restoring the vanilla PPHWSP */
1153 engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE,
1154 engine->context_size - PAGE_SIZE);
1156 execlists_init_reg_state(regs, ce, engine, ce->ring, false);
1159 static void reset_active(struct i915_request *rq,
1160 struct intel_engine_cs *engine)
1162 struct intel_context * const ce = rq->context;
1166 * The executing context has been cancelled. We want to prevent
1167 * further execution along this context and propagate the error on
1168 * to anything depending on its results.
1170 * In __i915_request_submit(), we apply the -EIO and remove the
1171 * requests' payloads for any banned requests. But first, we must
1172 * rewind the context back to the start of the incomplete request so
1173 * that we do not jump back into the middle of the batch.
1175 * We preserve the breadcrumbs and semaphores of the incomplete
1176 * requests so that inter-timeline dependencies (i.e other timelines)
1177 * remain correctly ordered. And we defer to __i915_request_submit()
1178 * so that all asynchronous waits are correctly handled.
1180 ENGINE_TRACE(engine, "{ rq=%llx:%lld }\n",
1181 rq->fence.context, rq->fence.seqno);
1183 /* On resubmission of the active request, payload will be scrubbed */
1184 if (i915_request_completed(rq))
1187 head = active_request(ce->timeline, rq)->head;
1188 head = intel_ring_wrap(ce->ring, head);
1190 /* Scrub the context image to prevent replaying the previous batch */
1191 restore_default_state(ce, engine);
1192 __execlists_update_reg_state(ce, engine, head);
1194 /* We've switched away, so this should be a no-op, but intent matters */
1195 ce->lrc_desc |= CTX_DESC_FORCE_RESTORE;
1198 static u32 intel_context_get_runtime(const struct intel_context *ce)
1201 * We can use either ppHWSP[16] which is recorded before the context
1202 * switch (and so excludes the cost of context switches) or use the
1203 * value from the context image itself, which is saved/restored earlier
1204 * and so includes the cost of the save.
1206 return READ_ONCE(ce->lrc_reg_state[CTX_TIMESTAMP]);
1209 static void st_update_runtime_underflow(struct intel_context *ce, s32 dt)
1211 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
1212 ce->runtime.num_underflow += dt < 0;
1213 ce->runtime.max_underflow = max_t(u32, ce->runtime.max_underflow, -dt);
1217 static void intel_context_update_runtime(struct intel_context *ce)
1222 if (intel_context_is_barrier(ce))
1225 old = ce->runtime.last;
1226 ce->runtime.last = intel_context_get_runtime(ce);
1227 dt = ce->runtime.last - old;
1229 if (unlikely(dt <= 0)) {
1230 CE_TRACE(ce, "runtime underflow: last=%u, new=%u, delta=%d\n",
1231 old, ce->runtime.last, dt);
1232 st_update_runtime_underflow(ce, dt);
1236 ewma_runtime_add(&ce->runtime.avg, dt);
1237 ce->runtime.total += dt;
1240 static inline struct intel_engine_cs *
1241 __execlists_schedule_in(struct i915_request *rq)
1243 struct intel_engine_cs * const engine = rq->engine;
1244 struct intel_context * const ce = rq->context;
1246 intel_context_get(ce);
1248 if (unlikely(intel_context_is_banned(ce)))
1249 reset_active(rq, engine);
1251 if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
1252 execlists_check_context(ce, engine);
1254 ce->lrc_desc &= ~GENMASK_ULL(47, 37);
1256 /* Use a fixed tag for OA and friends */
1257 ce->lrc_desc |= (u64)ce->tag << 32;
1259 /* We don't need a strict matching tag, just different values */
1261 (u64)(++engine->context_tag % NUM_CONTEXT_TAG) <<
1262 GEN11_SW_CTX_ID_SHIFT;
1263 BUILD_BUG_ON(NUM_CONTEXT_TAG > GEN12_MAX_CONTEXT_HW_ID);
1266 __intel_gt_pm_get(engine->gt);
1267 execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN);
1268 intel_engine_context_in(engine);
1273 static inline struct i915_request *
1274 execlists_schedule_in(struct i915_request *rq, int idx)
1276 struct intel_context * const ce = rq->context;
1277 struct intel_engine_cs *old;
1279 GEM_BUG_ON(!intel_engine_pm_is_awake(rq->engine));
1280 trace_i915_request_in(rq, idx);
1282 old = READ_ONCE(ce->inflight);
1285 WRITE_ONCE(ce->inflight, __execlists_schedule_in(rq));
1288 } while (!try_cmpxchg(&ce->inflight, &old, ptr_inc(old)));
1290 GEM_BUG_ON(intel_context_inflight(ce) != rq->engine);
1291 return i915_request_get(rq);
1294 static void kick_siblings(struct i915_request *rq, struct intel_context *ce)
1296 struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
1297 struct i915_request *next = READ_ONCE(ve->request);
1299 if (next && next->execution_mask & ~rq->execution_mask)
1300 tasklet_schedule(&ve->base.execlists.tasklet);
1304 __execlists_schedule_out(struct i915_request *rq,
1305 struct intel_engine_cs * const engine)
1307 struct intel_context * const ce = rq->context;
1310 * NB process_csb() is not under the engine->active.lock and hence
1311 * schedule_out can race with schedule_in meaning that we should
1312 * refrain from doing non-trivial work here.
1316 * If we have just completed this context, the engine may now be
1317 * idle and we want to re-enter powersaving.
1319 if (list_is_last_rcu(&rq->link, &ce->timeline->requests) &&
1320 i915_request_completed(rq))
1321 intel_engine_add_retire(engine, ce->timeline);
1323 intel_context_update_runtime(ce);
1324 intel_engine_context_out(engine);
1325 execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
1326 intel_gt_pm_put_async(engine->gt);
1329 * If this is part of a virtual engine, its next request may
1330 * have been blocked waiting for access to the active context.
1331 * We have to kick all the siblings again in case we need to
1332 * switch (e.g. the next request is not runnable on this
1333 * engine). Hopefully, we will already have submitted the next
1334 * request before the tasklet runs and do not need to rebuild
1335 * each virtual tree and kick everyone again.
1337 if (ce->engine != engine)
1338 kick_siblings(rq, ce);
1340 intel_context_put(ce);
1344 execlists_schedule_out(struct i915_request *rq)
1346 struct intel_context * const ce = rq->context;
1347 struct intel_engine_cs *cur, *old;
1349 trace_i915_request_out(rq);
1351 old = READ_ONCE(ce->inflight);
1353 cur = ptr_unmask_bits(old, 2) ? ptr_dec(old) : NULL;
1354 while (!try_cmpxchg(&ce->inflight, &old, cur));
1356 __execlists_schedule_out(rq, old);
1358 i915_request_put(rq);
1361 static u64 execlists_update_context(struct i915_request *rq)
1363 struct intel_context *ce = rq->context;
1364 u64 desc = ce->lrc_desc;
1368 * WaIdleLiteRestore:bdw,skl
1370 * We should never submit the context with the same RING_TAIL twice
1371 * just in case we submit an empty ring, which confuses the HW.
1373 * We append a couple of NOOPs (gen8_emit_wa_tail) after the end of
1374 * the normal request to be able to always advance the RING_TAIL on
1375 * subsequent resubmissions (for lite restore). Should that fail us,
1376 * and we try and submit the same tail again, force the context
1379 * If we need to return to a preempted context, we need to skip the
1380 * lite-restore and force it to reload the RING_TAIL. Otherwise, the
1381 * HW has a tendency to ignore us rewinding the TAIL to the end of
1382 * an earlier request.
1384 tail = intel_ring_set_tail(rq->ring, rq->tail);
1385 prev = ce->lrc_reg_state[CTX_RING_TAIL];
1386 if (unlikely(intel_ring_direction(rq->ring, tail, prev) <= 0))
1387 desc |= CTX_DESC_FORCE_RESTORE;
1388 ce->lrc_reg_state[CTX_RING_TAIL] = tail;
1389 rq->tail = rq->wa_tail;
1392 * Make sure the context image is complete before we submit it to HW.
1394 * Ostensibly, writes (including the WCB) should be flushed prior to
1395 * an uncached write such as our mmio register access, the empirical
1396 * evidence (esp. on Braswell) suggests that the WC write into memory
1397 * may not be visible to the HW prior to the completion of the UC
1398 * register write and that we may begin execution from the context
1399 * before its image is complete leading to invalid PD chasing.
1403 ce->lrc_desc &= ~CTX_DESC_FORCE_RESTORE;
1407 static inline void write_desc(struct intel_engine_execlists *execlists, u64 desc, u32 port)
1409 if (execlists->ctrl_reg) {
1410 writel(lower_32_bits(desc), execlists->submit_reg + port * 2);
1411 writel(upper_32_bits(desc), execlists->submit_reg + port * 2 + 1);
1413 writel(upper_32_bits(desc), execlists->submit_reg);
1414 writel(lower_32_bits(desc), execlists->submit_reg);
1418 static __maybe_unused void
1419 trace_ports(const struct intel_engine_execlists *execlists,
1421 struct i915_request * const *ports)
1423 const struct intel_engine_cs *engine =
1424 container_of(execlists, typeof(*engine), execlists);
1429 ENGINE_TRACE(engine, "%s { %llx:%lld%s, %llx:%lld }\n", msg,
1430 ports[0]->fence.context,
1431 ports[0]->fence.seqno,
1432 i915_request_completed(ports[0]) ? "!" :
1433 i915_request_started(ports[0]) ? "*" :
1435 ports[1] ? ports[1]->fence.context : 0,
1436 ports[1] ? ports[1]->fence.seqno : 0);
1440 reset_in_progress(const struct intel_engine_execlists *execlists)
1442 return unlikely(!__tasklet_is_enabled(&execlists->tasklet));
1445 static __maybe_unused bool
1446 assert_pending_valid(const struct intel_engine_execlists *execlists,
1449 struct i915_request * const *port, *rq;
1450 struct intel_context *ce = NULL;
1451 bool sentinel = false;
1453 trace_ports(execlists, msg, execlists->pending);
1455 /* We may be messing around with the lists during reset, lalala */
1456 if (reset_in_progress(execlists))
1459 if (!execlists->pending[0]) {
1460 GEM_TRACE_ERR("Nothing pending for promotion!\n");
1464 if (execlists->pending[execlists_num_ports(execlists)]) {
1465 GEM_TRACE_ERR("Excess pending[%d] for promotion!\n",
1466 execlists_num_ports(execlists));
1470 for (port = execlists->pending; (rq = *port); port++) {
1471 unsigned long flags;
1474 GEM_BUG_ON(!kref_read(&rq->fence.refcount));
1475 GEM_BUG_ON(!i915_request_is_active(rq));
1477 if (ce == rq->context) {
1478 GEM_TRACE_ERR("Dup context:%llx in pending[%zd]\n",
1479 ce->timeline->fence_context,
1480 port - execlists->pending);
1486 * Sentinels are supposed to be lonely so they flush the
1487 * current exection off the HW. Check that they are the
1488 * only request in the pending submission.
1491 GEM_TRACE_ERR("context:%llx after sentinel in pending[%zd]\n",
1492 ce->timeline->fence_context,
1493 port - execlists->pending);
1497 sentinel = i915_request_has_sentinel(rq);
1498 if (sentinel && port != execlists->pending) {
1499 GEM_TRACE_ERR("sentinel context:%llx not in prime position[%zd]\n",
1500 ce->timeline->fence_context,
1501 port - execlists->pending);
1505 /* Hold tightly onto the lock to prevent concurrent retires! */
1506 if (!spin_trylock_irqsave(&rq->lock, flags))
1509 if (i915_request_completed(rq))
1512 if (i915_active_is_idle(&ce->active) &&
1513 !intel_context_is_barrier(ce)) {
1514 GEM_TRACE_ERR("Inactive context:%llx in pending[%zd]\n",
1515 ce->timeline->fence_context,
1516 port - execlists->pending);
1521 if (!i915_vma_is_pinned(ce->state)) {
1522 GEM_TRACE_ERR("Unpinned context:%llx in pending[%zd]\n",
1523 ce->timeline->fence_context,
1524 port - execlists->pending);
1529 if (!i915_vma_is_pinned(ce->ring->vma)) {
1530 GEM_TRACE_ERR("Unpinned ring:%llx in pending[%zd]\n",
1531 ce->timeline->fence_context,
1532 port - execlists->pending);
1538 spin_unlock_irqrestore(&rq->lock, flags);
1546 static void execlists_submit_ports(struct intel_engine_cs *engine)
1548 struct intel_engine_execlists *execlists = &engine->execlists;
1551 GEM_BUG_ON(!assert_pending_valid(execlists, "submit"));
1554 * We can skip acquiring intel_runtime_pm_get() here as it was taken
1555 * on our behalf by the request (see i915_gem_mark_busy()) and it will
1556 * not be relinquished until the device is idle (see
1557 * i915_gem_idle_work_handler()). As a precaution, we make sure
1558 * that all ELSP are drained i.e. we have processed the CSB,
1559 * before allowing ourselves to idle and calling intel_runtime_pm_put().
1561 GEM_BUG_ON(!intel_engine_pm_is_awake(engine));
1564 * ELSQ note: the submit queue is not cleared after being submitted
1565 * to the HW so we need to make sure we always clean it up. This is
1566 * currently ensured by the fact that we always write the same number
1567 * of elsq entries, keep this in mind before changing the loop below.
1569 for (n = execlists_num_ports(execlists); n--; ) {
1570 struct i915_request *rq = execlists->pending[n];
1572 write_desc(execlists,
1573 rq ? execlists_update_context(rq) : 0,
1577 /* we need to manually load the submit queue */
1578 if (execlists->ctrl_reg)
1579 writel(EL_CTRL_LOAD, execlists->ctrl_reg);
1582 static bool ctx_single_port_submission(const struct intel_context *ce)
1584 return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
1585 intel_context_force_single_submission(ce));
1588 static bool can_merge_ctx(const struct intel_context *prev,
1589 const struct intel_context *next)
1594 if (ctx_single_port_submission(prev))
1600 static unsigned long i915_request_flags(const struct i915_request *rq)
1602 return READ_ONCE(rq->fence.flags);
1605 static bool can_merge_rq(const struct i915_request *prev,
1606 const struct i915_request *next)
1608 GEM_BUG_ON(prev == next);
1609 GEM_BUG_ON(!assert_priority_queue(prev, next));
1612 * We do not submit known completed requests. Therefore if the next
1613 * request is already completed, we can pretend to merge it in
1614 * with the previous context (and we will skip updating the ELSP
1615 * and tracking). Thus hopefully keeping the ELSP full with active
1616 * contexts, despite the best efforts of preempt-to-busy to confuse
1619 if (i915_request_completed(next))
1622 if (unlikely((i915_request_flags(prev) ^ i915_request_flags(next)) &
1623 (BIT(I915_FENCE_FLAG_NOPREEMPT) |
1624 BIT(I915_FENCE_FLAG_SENTINEL))))
1627 if (!can_merge_ctx(prev->context, next->context))
1630 GEM_BUG_ON(i915_seqno_passed(prev->fence.seqno, next->fence.seqno));
1634 static void virtual_update_register_offsets(u32 *regs,
1635 struct intel_engine_cs *engine)
1637 set_offsets(regs, reg_offsets(engine), engine, false);
1640 static bool virtual_matches(const struct virtual_engine *ve,
1641 const struct i915_request *rq,
1642 const struct intel_engine_cs *engine)
1644 const struct intel_engine_cs *inflight;
1646 if (!(rq->execution_mask & engine->mask)) /* We peeked too soon! */
1650 * We track when the HW has completed saving the context image
1651 * (i.e. when we have seen the final CS event switching out of
1652 * the context) and must not overwrite the context image before
1653 * then. This restricts us to only using the active engine
1654 * while the previous virtualized request is inflight (so
1655 * we reuse the register offsets). This is a very small
1656 * hystersis on the greedy seelction algorithm.
1658 inflight = intel_context_inflight(&ve->context);
1659 if (inflight && inflight != engine)
1665 static void virtual_xfer_breadcrumbs(struct virtual_engine *ve,
1666 struct i915_request *rq)
1668 struct intel_engine_cs *old = ve->siblings[0];
1670 /* All unattached (rq->engine == old) must already be completed */
1672 spin_lock(&old->breadcrumbs.irq_lock);
1673 if (!list_empty(&ve->context.signal_link)) {
1674 list_del_init(&ve->context.signal_link);
1677 * We cannot acquire the new engine->breadcrumbs.irq_lock
1678 * (as we are holding a breadcrumbs.irq_lock already),
1679 * so attach this request to the signaler on submission.
1680 * The queued irq_work will occur when we finally drop
1681 * the engine->active.lock after dequeue.
1683 set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags);
1685 /* Also transfer the pending irq_work for the old breadcrumb. */
1686 intel_engine_signal_breadcrumbs(rq->engine);
1688 spin_unlock(&old->breadcrumbs.irq_lock);
1691 #define for_each_waiter(p__, rq__) \
1692 list_for_each_entry_lockless(p__, \
1693 &(rq__)->sched.waiters_list, \
1696 #define for_each_signaler(p__, rq__) \
1697 list_for_each_entry_rcu(p__, \
1698 &(rq__)->sched.signalers_list, \
1701 static void defer_request(struct i915_request *rq, struct list_head * const pl)
1706 * We want to move the interrupted request to the back of
1707 * the round-robin list (i.e. its priority level), but
1708 * in doing so, we must then move all requests that were in
1709 * flight and were waiting for the interrupted request to
1710 * be run after it again.
1713 struct i915_dependency *p;
1715 GEM_BUG_ON(i915_request_is_active(rq));
1716 list_move_tail(&rq->sched.link, pl);
1718 for_each_waiter(p, rq) {
1719 struct i915_request *w =
1720 container_of(p->waiter, typeof(*w), sched);
1722 /* Leave semaphores spinning on the other engines */
1723 if (w->engine != rq->engine)
1726 /* No waiter should start before its signaler */
1727 GEM_BUG_ON(i915_request_started(w) &&
1728 !i915_request_completed(rq));
1730 GEM_BUG_ON(i915_request_is_active(w));
1731 if (!i915_request_is_ready(w))
1734 if (rq_prio(w) < rq_prio(rq))
1737 GEM_BUG_ON(rq_prio(w) > rq_prio(rq));
1738 list_move_tail(&w->sched.link, &list);
1741 rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
1745 static void defer_active(struct intel_engine_cs *engine)
1747 struct i915_request *rq;
1749 rq = __unwind_incomplete_requests(engine);
1753 defer_request(rq, i915_sched_lookup_priolist(engine, rq_prio(rq)));
1757 need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
1761 if (!intel_engine_has_timeslices(engine))
1764 hint = engine->execlists.queue_priority_hint;
1765 if (!list_is_last(&rq->sched.link, &engine->active.requests))
1766 hint = max(hint, rq_prio(list_next_entry(rq, sched.link)));
1768 return hint >= effective_prio(rq);
1772 switch_prio(struct intel_engine_cs *engine, const struct i915_request *rq)
1774 if (list_is_last(&rq->sched.link, &engine->active.requests))
1777 return rq_prio(list_next_entry(rq, sched.link));
1780 static inline unsigned long
1781 timeslice(const struct intel_engine_cs *engine)
1783 return READ_ONCE(engine->props.timeslice_duration_ms);
1786 static unsigned long
1787 active_timeslice(const struct intel_engine_cs *engine)
1789 const struct intel_engine_execlists *execlists = &engine->execlists;
1790 const struct i915_request *rq = *execlists->active;
1792 if (!rq || i915_request_completed(rq))
1795 if (READ_ONCE(execlists->switch_priority_hint) < effective_prio(rq))
1798 return timeslice(engine);
1801 static void set_timeslice(struct intel_engine_cs *engine)
1803 if (!intel_engine_has_timeslices(engine))
1806 set_timer_ms(&engine->execlists.timer, active_timeslice(engine));
1809 static void start_timeslice(struct intel_engine_cs *engine)
1811 struct intel_engine_execlists *execlists = &engine->execlists;
1812 int prio = queue_prio(execlists);
1814 WRITE_ONCE(execlists->switch_priority_hint, prio);
1815 if (prio == INT_MIN)
1818 if (timer_pending(&execlists->timer))
1821 set_timer_ms(&execlists->timer, timeslice(engine));
1824 static void record_preemption(struct intel_engine_execlists *execlists)
1826 (void)I915_SELFTEST_ONLY(execlists->preempt_hang.count++);
1829 static unsigned long active_preempt_timeout(struct intel_engine_cs *engine,
1830 const struct i915_request *rq)
1835 /* Force a fast reset for terminated contexts (ignoring sysfs!) */
1836 if (unlikely(intel_context_is_banned(rq->context)))
1839 return READ_ONCE(engine->props.preempt_timeout_ms);
1842 static void set_preempt_timeout(struct intel_engine_cs *engine,
1843 const struct i915_request *rq)
1845 if (!intel_engine_has_preempt_reset(engine))
1848 set_timer_ms(&engine->execlists.preempt,
1849 active_preempt_timeout(engine, rq));
1852 static inline void clear_ports(struct i915_request **ports, int count)
1854 memset_p((void **)ports, NULL, count);
1857 static void execlists_dequeue(struct intel_engine_cs *engine)
1859 struct intel_engine_execlists * const execlists = &engine->execlists;
1860 struct i915_request **port = execlists->pending;
1861 struct i915_request ** const last_port = port + execlists->port_mask;
1862 struct i915_request * const *active;
1863 struct i915_request *last;
1865 bool submit = false;
1868 * Hardware submission is through 2 ports. Conceptually each port
1869 * has a (RING_START, RING_HEAD, RING_TAIL) tuple. RING_START is
1870 * static for a context, and unique to each, so we only execute
1871 * requests belonging to a single context from each ring. RING_HEAD
1872 * is maintained by the CS in the context image, it marks the place
1873 * where it got up to last time, and through RING_TAIL we tell the CS
1874 * where we want to execute up to this time.
1876 * In this list the requests are in order of execution. Consecutive
1877 * requests from the same context are adjacent in the ringbuffer. We
1878 * can combine these requests into a single RING_TAIL update:
1880 * RING_HEAD...req1...req2
1882 * since to execute req2 the CS must first execute req1.
1884 * Our goal then is to point each port to the end of a consecutive
1885 * sequence of requests as being the most optimal (fewest wake ups
1886 * and context switches) submission.
1889 for (rb = rb_first_cached(&execlists->virtual); rb; ) {
1890 struct virtual_engine *ve =
1891 rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
1892 struct i915_request *rq = READ_ONCE(ve->request);
1894 if (!rq) { /* lazily cleanup after another engine handled rq */
1895 rb_erase_cached(rb, &execlists->virtual);
1897 rb = rb_first_cached(&execlists->virtual);
1901 if (!virtual_matches(ve, rq, engine)) {
1910 * If the queue is higher priority than the last
1911 * request in the currently active context, submit afresh.
1912 * We will resubmit again afterwards in case we need to split
1913 * the active context to interject the preemption request,
1914 * i.e. we will retrigger preemption following the ack in case
1917 active = READ_ONCE(execlists->active);
1918 while ((last = *active) && i915_request_completed(last))
1922 if (need_preempt(engine, last, rb)) {
1923 ENGINE_TRACE(engine,
1924 "preempting last=%llx:%lld, prio=%d, hint=%d\n",
1925 last->fence.context,
1927 last->sched.attr.priority,
1928 execlists->queue_priority_hint);
1929 record_preemption(execlists);
1932 * Don't let the RING_HEAD advance past the breadcrumb
1933 * as we unwind (and until we resubmit) so that we do
1934 * not accidentally tell it to go backwards.
1936 ring_set_paused(engine, 1);
1939 * Note that we have not stopped the GPU at this point,
1940 * so we are unwinding the incomplete requests as they
1941 * remain inflight and so by the time we do complete
1942 * the preemption, some of the unwound requests may
1945 __unwind_incomplete_requests(engine);
1948 } else if (need_timeslice(engine, last) &&
1949 timer_expired(&engine->execlists.timer)) {
1950 ENGINE_TRACE(engine,
1951 "expired last=%llx:%lld, prio=%d, hint=%d\n",
1952 last->fence.context,
1954 last->sched.attr.priority,
1955 execlists->queue_priority_hint);
1957 ring_set_paused(engine, 1);
1958 defer_active(engine);
1961 * Unlike for preemption, if we rewind and continue
1962 * executing the same context as previously active,
1963 * the order of execution will remain the same and
1964 * the tail will only advance. We do not need to
1965 * force a full context restore, as a lite-restore
1966 * is sufficient to resample the monotonic TAIL.
1968 * If we switch to any other context, similarly we
1969 * will not rewind TAIL of current context, and
1970 * normal save/restore will preserve state and allow
1971 * us to later continue executing the same request.
1976 * Otherwise if we already have a request pending
1977 * for execution after the current one, we can
1978 * just wait until the next CS event before
1979 * queuing more. In either case we will force a
1980 * lite-restore preemption event, but if we wait
1981 * we hopefully coalesce several updates into a single
1984 if (!list_is_last(&last->sched.link,
1985 &engine->active.requests)) {
1987 * Even if ELSP[1] is occupied and not worthy
1988 * of timeslices, our queue might be.
1990 start_timeslice(engine);
1996 while (rb) { /* XXX virtual is always taking precedence */
1997 struct virtual_engine *ve =
1998 rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
1999 struct i915_request *rq;
2001 spin_lock(&ve->base.active.lock);
2004 if (unlikely(!rq)) { /* lost the race to a sibling */
2005 spin_unlock(&ve->base.active.lock);
2006 rb_erase_cached(rb, &execlists->virtual);
2008 rb = rb_first_cached(&execlists->virtual);
2012 GEM_BUG_ON(rq != ve->request);
2013 GEM_BUG_ON(rq->engine != &ve->base);
2014 GEM_BUG_ON(rq->context != &ve->context);
2016 if (rq_prio(rq) >= queue_prio(execlists)) {
2017 if (!virtual_matches(ve, rq, engine)) {
2018 spin_unlock(&ve->base.active.lock);
2023 if (last && !can_merge_rq(last, rq)) {
2024 spin_unlock(&ve->base.active.lock);
2025 start_timeslice(engine);
2026 return; /* leave this for another sibling */
2029 ENGINE_TRACE(engine,
2030 "virtual rq=%llx:%lld%s, new engine? %s\n",
2033 i915_request_completed(rq) ? "!" :
2034 i915_request_started(rq) ? "*" :
2036 yesno(engine != ve->siblings[0]));
2038 WRITE_ONCE(ve->request, NULL);
2039 WRITE_ONCE(ve->base.execlists.queue_priority_hint,
2041 rb_erase_cached(rb, &execlists->virtual);
2044 GEM_BUG_ON(!(rq->execution_mask & engine->mask));
2045 WRITE_ONCE(rq->engine, engine);
2047 if (engine != ve->siblings[0]) {
2048 u32 *regs = ve->context.lrc_reg_state;
2051 GEM_BUG_ON(READ_ONCE(ve->context.inflight));
2053 if (!intel_engine_has_relative_mmio(engine))
2054 virtual_update_register_offsets(regs,
2057 if (!list_empty(&ve->context.signals))
2058 virtual_xfer_breadcrumbs(ve, rq);
2061 * Move the bound engine to the top of the list
2062 * for future execution. We then kick this
2063 * tasklet first before checking others, so that
2064 * we preferentially reuse this set of bound
2067 for (n = 1; n < ve->num_siblings; n++) {
2068 if (ve->siblings[n] == engine) {
2069 swap(ve->siblings[n],
2075 GEM_BUG_ON(ve->siblings[0] != engine);
2078 if (__i915_request_submit(rq)) {
2082 i915_request_put(rq);
2085 * Hmm, we have a bunch of virtual engine requests,
2086 * but the first one was already completed (thanks
2087 * preempt-to-busy!). Keep looking at the veng queue
2088 * until we have no more relevant requests (i.e.
2089 * the normal submit queue has higher priority).
2092 spin_unlock(&ve->base.active.lock);
2093 rb = rb_first_cached(&execlists->virtual);
2098 spin_unlock(&ve->base.active.lock);
2102 while ((rb = rb_first_cached(&execlists->queue))) {
2103 struct i915_priolist *p = to_priolist(rb);
2104 struct i915_request *rq, *rn;
2107 priolist_for_each_request_consume(rq, rn, p, i) {
2111 * Can we combine this request with the current port?
2112 * It has to be the same context/ringbuffer and not
2113 * have any exceptions (e.g. GVT saying never to
2114 * combine contexts).
2116 * If we can combine the requests, we can execute both
2117 * by updating the RING_TAIL to point to the end of the
2118 * second request, and so we never need to tell the
2119 * hardware about the first.
2121 if (last && !can_merge_rq(last, rq)) {
2123 * If we are on the second port and cannot
2124 * combine this request with the last, then we
2127 if (port == last_port)
2131 * We must not populate both ELSP[] with the
2132 * same LRCA, i.e. we must submit 2 different
2133 * contexts if we submit 2 ELSP.
2135 if (last->context == rq->context)
2138 if (i915_request_has_sentinel(last))
2142 * If GVT overrides us we only ever submit
2143 * port[0], leaving port[1] empty. Note that we
2144 * also have to be careful that we don't queue
2145 * the same context (even though a different
2146 * request) to the second port.
2148 if (ctx_single_port_submission(last->context) ||
2149 ctx_single_port_submission(rq->context))
2155 if (__i915_request_submit(rq)) {
2157 *port = execlists_schedule_in(last, port - execlists->pending);
2163 !can_merge_ctx(last->context,
2166 i915_seqno_passed(last->fence.seqno,
2174 rb_erase_cached(&p->node, &execlists->queue);
2175 i915_priolist_free(p);
2180 * Here be a bit of magic! Or sleight-of-hand, whichever you prefer.
2182 * We choose the priority hint such that if we add a request of greater
2183 * priority than this, we kick the submission tasklet to decide on
2184 * the right order of submitting the requests to hardware. We must
2185 * also be prepared to reorder requests as they are in-flight on the
2186 * HW. We derive the priority hint then as the first "hole" in
2187 * the HW submission ports and if there are no available slots,
2188 * the priority of the lowest executing request, i.e. last.
2190 * When we do receive a higher priority request ready to run from the
2191 * user, see queue_request(), the priority hint is bumped to that
2192 * request triggering preemption on the next dequeue (or subsequent
2193 * interrupt for secondary ports).
2195 execlists->queue_priority_hint = queue_prio(execlists);
2198 *port = execlists_schedule_in(last, port - execlists->pending);
2199 execlists->switch_priority_hint =
2200 switch_prio(engine, *execlists->pending);
2203 * Skip if we ended up with exactly the same set of requests,
2204 * e.g. trying to timeslice a pair of ordered contexts
2206 if (!memcmp(active, execlists->pending,
2207 (port - execlists->pending + 1) * sizeof(*port))) {
2209 execlists_schedule_out(fetch_and_zero(port));
2210 while (port-- != execlists->pending);
2214 clear_ports(port + 1, last_port - port);
2216 execlists_submit_ports(engine);
2217 set_preempt_timeout(engine, *active);
2220 ring_set_paused(engine, 0);
2225 cancel_port_requests(struct intel_engine_execlists * const execlists)
2227 struct i915_request * const *port;
2229 for (port = execlists->pending; *port; port++)
2230 execlists_schedule_out(*port);
2231 clear_ports(execlists->pending, ARRAY_SIZE(execlists->pending));
2233 /* Mark the end of active before we overwrite *active */
2234 for (port = xchg(&execlists->active, execlists->pending); *port; port++)
2235 execlists_schedule_out(*port);
2236 clear_ports(execlists->inflight, ARRAY_SIZE(execlists->inflight));
2238 smp_wmb(); /* complete the seqlock for execlists_active() */
2239 WRITE_ONCE(execlists->active, execlists->inflight);
2243 invalidate_csb_entries(const u32 *first, const u32 *last)
2245 clflush((void *)first);
2246 clflush((void *)last);
2250 * Starting with Gen12, the status has a new format:
2252 * bit 0: switched to new queue
2254 * bit 2: semaphore wait mode (poll or signal), only valid when
2255 * switch detail is set to "wait on semaphore"
2256 * bits 3-5: engine class
2257 * bits 6-11: engine instance
2258 * bits 12-14: reserved
2259 * bits 15-25: sw context id of the lrc the GT switched to
2260 * bits 26-31: sw counter of the lrc the GT switched to
2261 * bits 32-35: context switch detail
2263 * - 1: wait on sync flip
2264 * - 2: wait on vblank
2265 * - 3: wait on scanline
2266 * - 4: wait on semaphore
2267 * - 5: context preempted (not on SEMAPHORE_WAIT or
2270 * bits 37-43: wait detail (for switch detail 1 to 4)
2271 * bits 44-46: reserved
2272 * bits 47-57: sw context id of the lrc the GT switched away from
2273 * bits 58-63: sw counter of the lrc the GT switched away from
2276 gen12_csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb)
2278 u32 lower_dw = csb[0];
2279 u32 upper_dw = csb[1];
2280 bool ctx_to_valid = GEN12_CSB_CTX_VALID(lower_dw);
2281 bool ctx_away_valid = GEN12_CSB_CTX_VALID(upper_dw);
2282 bool new_queue = lower_dw & GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE;
2285 * The context switch detail is not guaranteed to be 5 when a preemption
2286 * occurs, so we can't just check for that. The check below works for
2287 * all the cases we care about, including preemptions of WAIT
2288 * instructions and lite-restore. Preempt-to-idle via the CTRL register
2289 * would require some extra handling, but we don't support that.
2291 if (!ctx_away_valid || new_queue) {
2292 GEM_BUG_ON(!ctx_to_valid);
2297 * switch detail = 5 is covered by the case above and we do not expect a
2298 * context switch on an unsuccessful wait instruction since we always
2301 GEM_BUG_ON(GEN12_CTX_SWITCH_DETAIL(upper_dw));
2306 gen8_csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb)
2308 return *csb & (GEN8_CTX_STATUS_IDLE_ACTIVE | GEN8_CTX_STATUS_PREEMPTED);
2311 static void process_csb(struct intel_engine_cs *engine)
2313 struct intel_engine_execlists * const execlists = &engine->execlists;
2314 const u32 * const buf = execlists->csb_status;
2315 const u8 num_entries = execlists->csb_size;
2319 * As we modify our execlists state tracking we require exclusive
2320 * access. Either we are inside the tasklet, or the tasklet is disabled
2321 * and we assume that is only inside the reset paths and so serialised.
2323 GEM_BUG_ON(!tasklet_is_locked(&execlists->tasklet) &&
2324 !reset_in_progress(execlists));
2325 GEM_BUG_ON(!intel_engine_in_execlists_submission_mode(engine));
2328 * Note that csb_write, csb_status may be either in HWSP or mmio.
2329 * When reading from the csb_write mmio register, we have to be
2330 * careful to only use the GEN8_CSB_WRITE_PTR portion, which is
2331 * the low 4bits. As it happens we know the next 4bits are always
2332 * zero and so we can simply masked off the low u8 of the register
2333 * and treat it identically to reading from the HWSP (without having
2334 * to use explicit shifting and masking, and probably bifurcating
2335 * the code to handle the legacy mmio read).
2337 head = execlists->csb_head;
2338 tail = READ_ONCE(*execlists->csb_write);
2339 if (unlikely(head == tail))
2343 * Hopefully paired with a wmb() in HW!
2345 * We must complete the read of the write pointer before any reads
2346 * from the CSB, so that we do not see stale values. Without an rmb
2347 * (lfence) the HW may speculatively perform the CSB[] reads *before*
2348 * we perform the READ_ONCE(*csb_write).
2352 ENGINE_TRACE(engine, "cs-irq head=%d, tail=%d\n", head, tail);
2356 if (++head == num_entries)
2360 * We are flying near dragons again.
2362 * We hold a reference to the request in execlist_port[]
2363 * but no more than that. We are operating in softirq
2364 * context and so cannot hold any mutex or sleep. That
2365 * prevents us stopping the requests we are processing
2366 * in port[] from being retired simultaneously (the
2367 * breadcrumb will be complete before we see the
2368 * context-switch). As we only hold the reference to the
2369 * request, any pointer chasing underneath the request
2370 * is subject to a potential use-after-free. Thus we
2371 * store all of the bookkeeping within port[] as
2372 * required, and avoid using unguarded pointers beneath
2373 * request itself. The same applies to the atomic
2377 ENGINE_TRACE(engine, "csb[%d]: status=0x%08x:0x%08x\n",
2378 head, buf[2 * head + 0], buf[2 * head + 1]);
2380 if (INTEL_GEN(engine->i915) >= 12)
2381 promote = gen12_csb_parse(execlists, buf + 2 * head);
2383 promote = gen8_csb_parse(execlists, buf + 2 * head);
2385 struct i915_request * const *old = execlists->active;
2387 GEM_BUG_ON(!assert_pending_valid(execlists, "promote"));
2389 ring_set_paused(engine, 0);
2391 /* Point active to the new ELSP; prevent overwriting */
2392 WRITE_ONCE(execlists->active, execlists->pending);
2393 smp_wmb(); /* notify execlists_active() */
2395 /* cancel old inflight, prepare for switch */
2396 trace_ports(execlists, "preempted", old);
2398 execlists_schedule_out(*old++);
2400 /* switch pending to inflight */
2401 memcpy(execlists->inflight,
2403 execlists_num_ports(execlists) *
2404 sizeof(*execlists->pending));
2405 smp_wmb(); /* complete the seqlock */
2406 WRITE_ONCE(execlists->active, execlists->inflight);
2408 WRITE_ONCE(execlists->pending[0], NULL);
2410 GEM_BUG_ON(!*execlists->active);
2412 /* port0 completed, advanced to port1 */
2413 trace_ports(execlists, "completed", execlists->active);
2416 * We rely on the hardware being strongly
2417 * ordered, that the breadcrumb write is
2418 * coherent (visible from the CPU) before the
2419 * user interrupt and CSB is processed.
2421 if (GEM_SHOW_DEBUG() &&
2422 !i915_request_completed(*execlists->active) &&
2423 !reset_in_progress(execlists)) {
2424 struct i915_request *rq __maybe_unused =
2426 const u32 *regs __maybe_unused =
2427 rq->context->lrc_reg_state;
2429 ENGINE_TRACE(engine,
2430 "ring:{start:0x%08x, head:%04x, tail:%04x, ctl:%08x, mode:%08x}\n",
2431 ENGINE_READ(engine, RING_START),
2432 ENGINE_READ(engine, RING_HEAD) & HEAD_ADDR,
2433 ENGINE_READ(engine, RING_TAIL) & TAIL_ADDR,
2434 ENGINE_READ(engine, RING_CTL),
2435 ENGINE_READ(engine, RING_MI_MODE));
2436 ENGINE_TRACE(engine,
2437 "rq:{start:%08x, head:%04x, tail:%04x, seqno:%llx:%d, hwsp:%d}, ",
2438 i915_ggtt_offset(rq->ring->vma),
2441 lower_32_bits(rq->fence.seqno),
2443 ENGINE_TRACE(engine,
2444 "ctx:{start:%08x, head:%04x, tail:%04x}, ",
2445 regs[CTX_RING_START],
2446 regs[CTX_RING_HEAD],
2447 regs[CTX_RING_TAIL]);
2449 GEM_BUG_ON("context completed before request");
2452 execlists_schedule_out(*execlists->active++);
2454 GEM_BUG_ON(execlists->active - execlists->inflight >
2455 execlists_num_ports(execlists));
2457 } while (head != tail);
2459 execlists->csb_head = head;
2460 set_timeslice(engine);
2463 * Gen11 has proven to fail wrt global observation point between
2464 * entry and tail update, failing on the ordering and thus
2465 * we see an old entry in the context status buffer.
2467 * Forcibly evict out entries for the next gpu csb update,
2468 * to increase the odds that we get a fresh entries with non
2469 * working hardware. The cost for doing so comes out mostly with
2470 * the wash as hardware, working or not, will need to do the
2471 * invalidation before.
2473 invalidate_csb_entries(&buf[0], &buf[num_entries - 1]);
2476 static void __execlists_submission_tasklet(struct intel_engine_cs *const engine)
2478 lockdep_assert_held(&engine->active.lock);
2479 if (!READ_ONCE(engine->execlists.pending[0])) {
2480 rcu_read_lock(); /* protect peeking at execlists->active */
2481 execlists_dequeue(engine);
2486 static void __execlists_hold(struct i915_request *rq)
2491 struct i915_dependency *p;
2493 if (i915_request_is_active(rq))
2494 __i915_request_unsubmit(rq);
2496 clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
2497 list_move_tail(&rq->sched.link, &rq->engine->active.hold);
2498 i915_request_set_hold(rq);
2499 RQ_TRACE(rq, "on hold\n");
2501 for_each_waiter(p, rq) {
2502 struct i915_request *w =
2503 container_of(p->waiter, typeof(*w), sched);
2505 /* Leave semaphores spinning on the other engines */
2506 if (w->engine != rq->engine)
2509 if (!i915_request_is_ready(w))
2512 if (i915_request_completed(w))
2515 if (i915_request_on_hold(w))
2518 list_move_tail(&w->sched.link, &list);
2521 rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
2525 static bool execlists_hold(struct intel_engine_cs *engine,
2526 struct i915_request *rq)
2528 spin_lock_irq(&engine->active.lock);
2530 if (i915_request_completed(rq)) { /* too late! */
2535 if (rq->engine != engine) { /* preempted virtual engine */
2536 struct virtual_engine *ve = to_virtual_engine(rq->engine);
2539 * intel_context_inflight() is only protected by virtue
2540 * of process_csb() being called only by the tasklet (or
2541 * directly from inside reset while the tasklet is suspended).
2542 * Assert that neither of those are allowed to run while we
2543 * poke at the request queues.
2545 GEM_BUG_ON(!reset_in_progress(&engine->execlists));
2548 * An unsubmitted request along a virtual engine will
2549 * remain on the active (this) engine until we are able
2550 * to process the context switch away (and so mark the
2551 * context as no longer in flight). That cannot have happened
2552 * yet, otherwise we would not be hanging!
2554 spin_lock(&ve->base.active.lock);
2555 GEM_BUG_ON(intel_context_inflight(rq->context) != engine);
2556 GEM_BUG_ON(ve->request != rq);
2558 spin_unlock(&ve->base.active.lock);
2559 i915_request_put(rq);
2561 rq->engine = engine;
2565 * Transfer this request onto the hold queue to prevent it
2566 * being resumbitted to HW (and potentially completed) before we have
2567 * released it. Since we may have already submitted following
2568 * requests, we need to remove those as well.
2570 GEM_BUG_ON(i915_request_on_hold(rq));
2571 GEM_BUG_ON(rq->engine != engine);
2572 __execlists_hold(rq);
2573 GEM_BUG_ON(list_empty(&engine->active.hold));
2576 spin_unlock_irq(&engine->active.lock);
2580 static bool hold_request(const struct i915_request *rq)
2582 struct i915_dependency *p;
2583 bool result = false;
2586 * If one of our ancestors is on hold, we must also be on hold,
2587 * otherwise we will bypass it and execute before it.
2590 for_each_signaler(p, rq) {
2591 const struct i915_request *s =
2592 container_of(p->signaler, typeof(*s), sched);
2594 if (s->engine != rq->engine)
2597 result = i915_request_on_hold(s);
2606 static void __execlists_unhold(struct i915_request *rq)
2611 struct i915_dependency *p;
2613 RQ_TRACE(rq, "hold release\n");
2615 GEM_BUG_ON(!i915_request_on_hold(rq));
2616 GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));
2618 i915_request_clear_hold(rq);
2619 list_move_tail(&rq->sched.link,
2620 i915_sched_lookup_priolist(rq->engine,
2622 set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
2624 /* Also release any children on this engine that are ready */
2625 for_each_waiter(p, rq) {
2626 struct i915_request *w =
2627 container_of(p->waiter, typeof(*w), sched);
2629 /* Propagate any change in error status */
2630 if (rq->fence.error)
2631 i915_request_set_error_once(w, rq->fence.error);
2633 if (w->engine != rq->engine)
2636 if (!i915_request_on_hold(w))
2639 /* Check that no other parents are also on hold */
2640 if (hold_request(w))
2643 list_move_tail(&w->sched.link, &list);
2646 rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
2650 static void execlists_unhold(struct intel_engine_cs *engine,
2651 struct i915_request *rq)
2653 spin_lock_irq(&engine->active.lock);
2656 * Move this request back to the priority queue, and all of its
2657 * children and grandchildren that were suspended along with it.
2659 __execlists_unhold(rq);
2661 if (rq_prio(rq) > engine->execlists.queue_priority_hint) {
2662 engine->execlists.queue_priority_hint = rq_prio(rq);
2663 tasklet_hi_schedule(&engine->execlists.tasklet);
2666 spin_unlock_irq(&engine->active.lock);
2669 struct execlists_capture {
2670 struct work_struct work;
2671 struct i915_request *rq;
2672 struct i915_gpu_coredump *error;
2675 static void execlists_capture_work(struct work_struct *work)
2677 struct execlists_capture *cap = container_of(work, typeof(*cap), work);
2678 const gfp_t gfp = GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
2679 struct intel_engine_cs *engine = cap->rq->engine;
2680 struct intel_gt_coredump *gt = cap->error->gt;
2681 struct intel_engine_capture_vma *vma;
2683 /* Compress all the objects attached to the request, slow! */
2684 vma = intel_engine_coredump_add_request(gt->engine, cap->rq, gfp);
2686 struct i915_vma_compress *compress =
2687 i915_vma_capture_prepare(gt);
2689 intel_engine_coredump_add_vma(gt->engine, vma, compress);
2690 i915_vma_capture_finish(gt, compress);
2693 gt->simulated = gt->engine->simulated;
2694 cap->error->simulated = gt->simulated;
2696 /* Publish the error state, and announce it to the world */
2697 i915_error_state_store(cap->error);
2698 i915_gpu_coredump_put(cap->error);
2700 /* Return this request and all that depend upon it for signaling */
2701 execlists_unhold(engine, cap->rq);
2702 i915_request_put(cap->rq);
2707 static struct execlists_capture *capture_regs(struct intel_engine_cs *engine)
2709 const gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN;
2710 struct execlists_capture *cap;
2712 cap = kmalloc(sizeof(*cap), gfp);
2716 cap->error = i915_gpu_coredump_alloc(engine->i915, gfp);
2720 cap->error->gt = intel_gt_coredump_alloc(engine->gt, gfp);
2721 if (!cap->error->gt)
2724 cap->error->gt->engine = intel_engine_coredump_alloc(engine, gfp);
2725 if (!cap->error->gt->engine)
2731 kfree(cap->error->gt);
2739 static bool execlists_capture(struct intel_engine_cs *engine)
2741 struct execlists_capture *cap;
2743 if (!IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR))
2747 * We need to _quickly_ capture the engine state before we reset.
2748 * We are inside an atomic section (softirq) here and we are delaying
2749 * the forced preemption event.
2751 cap = capture_regs(engine);
2755 spin_lock_irq(&engine->active.lock);
2756 cap->rq = execlists_active(&engine->execlists);
2758 cap->rq = active_request(cap->rq->context->timeline, cap->rq);
2759 cap->rq = i915_request_get_rcu(cap->rq);
2761 spin_unlock_irq(&engine->active.lock);
2766 * Remove the request from the execlists queue, and take ownership
2767 * of the request. We pass it to our worker who will _slowly_ compress
2768 * all the pages the _user_ requested for debugging their batch, after
2769 * which we return it to the queue for signaling.
2771 * By removing them from the execlists queue, we also remove the
2772 * requests from being processed by __unwind_incomplete_requests()
2773 * during the intel_engine_reset(), and so they will *not* be replayed
2776 * Note that because we have not yet reset the engine at this point,
2777 * it is possible for the request that we have identified as being
2778 * guilty, did in fact complete and we will then hit an arbitration
2779 * point allowing the outstanding preemption to succeed. The likelihood
2780 * of that is very low (as capturing of the engine registers should be
2781 * fast enough to run inside an irq-off atomic section!), so we will
2782 * simply hold that request accountable for being non-preemptible
2783 * long enough to force the reset.
2785 if (!execlists_hold(engine, cap->rq))
2788 INIT_WORK(&cap->work, execlists_capture_work);
2789 schedule_work(&cap->work);
2793 i915_request_put(cap->rq);
2795 i915_gpu_coredump_put(cap->error);
2800 static void execlists_reset(struct intel_engine_cs *engine, const char *msg)
2802 const unsigned int bit = I915_RESET_ENGINE + engine->id;
2803 unsigned long *lock = &engine->gt->reset.flags;
2805 if (!intel_has_reset_engine(engine->gt))
2808 if (test_and_set_bit(bit, lock))
2811 ENGINE_TRACE(engine, "reset for %s\n", msg);
2813 /* Mark this tasklet as disabled to avoid waiting for it to complete */
2814 tasklet_disable_nosync(&engine->execlists.tasklet);
2816 ring_set_paused(engine, 1); /* Freeze the current request in place */
2817 if (execlists_capture(engine))
2818 intel_engine_reset(engine, msg);
2820 ring_set_paused(engine, 0);
2822 tasklet_enable(&engine->execlists.tasklet);
2823 clear_and_wake_up_bit(bit, lock);
2826 static bool preempt_timeout(const struct intel_engine_cs *const engine)
2828 const struct timer_list *t = &engine->execlists.preempt;
2830 if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT)
2833 if (!timer_expired(t))
2836 return READ_ONCE(engine->execlists.pending[0]);
2840 * Check the unread Context Status Buffers and manage the submission of new
2841 * contexts to the ELSP accordingly.
2843 static void execlists_submission_tasklet(unsigned long data)
2845 struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
2846 bool timeout = preempt_timeout(engine);
2848 process_csb(engine);
2850 if (unlikely(READ_ONCE(engine->execlists.error_interrupt))) {
2851 engine->execlists.error_interrupt = 0;
2852 if (ENGINE_READ(engine, RING_ESR)) /* confirm the error */
2853 execlists_reset(engine, "CS error");
2856 if (!READ_ONCE(engine->execlists.pending[0]) || timeout) {
2857 unsigned long flags;
2859 spin_lock_irqsave(&engine->active.lock, flags);
2860 __execlists_submission_tasklet(engine);
2861 spin_unlock_irqrestore(&engine->active.lock, flags);
2863 /* Recheck after serialising with direct-submission */
2864 if (unlikely(timeout && preempt_timeout(engine)))
2865 execlists_reset(engine, "preemption time out");
2869 static void __execlists_kick(struct intel_engine_execlists *execlists)
2871 /* Kick the tasklet for some interrupt coalescing and reset handling */
2872 tasklet_hi_schedule(&execlists->tasklet);
2875 #define execlists_kick(t, member) \
2876 __execlists_kick(container_of(t, struct intel_engine_execlists, member))
2878 static void execlists_timeslice(struct timer_list *timer)
2880 execlists_kick(timer, timer);
2883 static void execlists_preempt(struct timer_list *timer)
2885 execlists_kick(timer, preempt);
2888 static void queue_request(struct intel_engine_cs *engine,
2889 struct i915_request *rq)
2891 GEM_BUG_ON(!list_empty(&rq->sched.link));
2892 list_add_tail(&rq->sched.link,
2893 i915_sched_lookup_priolist(engine, rq_prio(rq)));
2894 set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
2897 static void __submit_queue_imm(struct intel_engine_cs *engine)
2899 struct intel_engine_execlists * const execlists = &engine->execlists;
2901 if (reset_in_progress(execlists))
2902 return; /* defer until we restart the engine following reset */
2904 if (execlists->tasklet.func == execlists_submission_tasklet)
2905 __execlists_submission_tasklet(engine);
2907 tasklet_hi_schedule(&execlists->tasklet);
2910 static void submit_queue(struct intel_engine_cs *engine,
2911 const struct i915_request *rq)
2913 struct intel_engine_execlists *execlists = &engine->execlists;
2915 if (rq_prio(rq) <= execlists->queue_priority_hint)
2918 execlists->queue_priority_hint = rq_prio(rq);
2919 __submit_queue_imm(engine);
2922 static bool ancestor_on_hold(const struct intel_engine_cs *engine,
2923 const struct i915_request *rq)
2925 GEM_BUG_ON(i915_request_on_hold(rq));
2926 return !list_empty(&engine->active.hold) && hold_request(rq);
2929 static void execlists_submit_request(struct i915_request *request)
2931 struct intel_engine_cs *engine = request->engine;
2932 unsigned long flags;
2934 /* Will be called from irq-context when using foreign fences. */
2935 spin_lock_irqsave(&engine->active.lock, flags);
2937 if (unlikely(ancestor_on_hold(engine, request))) {
2938 RQ_TRACE(request, "ancestor on hold\n");
2939 list_add_tail(&request->sched.link, &engine->active.hold);
2940 i915_request_set_hold(request);
2942 queue_request(engine, request);
2944 GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
2945 GEM_BUG_ON(list_empty(&request->sched.link));
2947 submit_queue(engine, request);
2950 spin_unlock_irqrestore(&engine->active.lock, flags);
2953 static void __execlists_context_fini(struct intel_context *ce)
2955 intel_ring_put(ce->ring);
2956 i915_vma_put(ce->state);
2959 static void execlists_context_destroy(struct kref *kref)
2961 struct intel_context *ce = container_of(kref, typeof(*ce), ref);
2963 GEM_BUG_ON(!i915_active_is_idle(&ce->active));
2964 GEM_BUG_ON(intel_context_is_pinned(ce));
2967 __execlists_context_fini(ce);
2969 intel_context_fini(ce);
2970 intel_context_free(ce);
2974 set_redzone(void *vaddr, const struct intel_engine_cs *engine)
2976 if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
2979 vaddr += engine->context_size;
2981 memset(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE);
2985 check_redzone(const void *vaddr, const struct intel_engine_cs *engine)
2987 if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
2990 vaddr += engine->context_size;
2992 if (memchr_inv(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE))
2993 dev_err_once(engine->i915->drm.dev,
2994 "%s context redzone overwritten!\n",
2998 static void execlists_context_unpin(struct intel_context *ce)
3000 check_redzone((void *)ce->lrc_reg_state - LRC_STATE_PN * PAGE_SIZE,
3003 i915_gem_object_unpin_map(ce->state->obj);
3007 __execlists_update_reg_state(const struct intel_context *ce,
3008 const struct intel_engine_cs *engine,
3011 struct intel_ring *ring = ce->ring;
3012 u32 *regs = ce->lrc_reg_state;
3014 GEM_BUG_ON(!intel_ring_offset_valid(ring, head));
3015 GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->tail));
3017 regs[CTX_RING_START] = i915_ggtt_offset(ring->vma);
3018 regs[CTX_RING_HEAD] = head;
3019 regs[CTX_RING_TAIL] = ring->tail;
3020 regs[CTX_RING_CTL] = RING_CTL_SIZE(ring->size) | RING_VALID;
3023 if (engine->class == RENDER_CLASS) {
3024 regs[CTX_R_PWR_CLK_STATE] =
3025 intel_sseu_make_rpcs(engine->i915, &ce->sseu);
3027 i915_oa_init_reg_state(ce, engine);
3032 __execlists_context_pin(struct intel_context *ce,
3033 struct intel_engine_cs *engine)
3037 GEM_BUG_ON(!ce->state);
3038 GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
3040 vaddr = i915_gem_object_pin_map(ce->state->obj,
3041 i915_coherent_map_type(engine->i915) |
3044 return PTR_ERR(vaddr);
3046 ce->lrc_desc = lrc_descriptor(ce, engine) | CTX_DESC_FORCE_RESTORE;
3047 ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE;
3048 __execlists_update_reg_state(ce, engine, ce->ring->tail);
3053 static int execlists_context_pin(struct intel_context *ce)
3055 return __execlists_context_pin(ce, ce->engine);
3058 static int execlists_context_alloc(struct intel_context *ce)
3060 return __execlists_context_alloc(ce, ce->engine);
3063 static void execlists_context_reset(struct intel_context *ce)
3065 CE_TRACE(ce, "reset\n");
3066 GEM_BUG_ON(!intel_context_is_pinned(ce));
3068 intel_ring_reset(ce->ring, ce->ring->emit);
3070 /* Scrub away the garbage */
3071 execlists_init_reg_state(ce->lrc_reg_state,
3072 ce, ce->engine, ce->ring, true);
3073 __execlists_update_reg_state(ce, ce->engine, ce->ring->tail);
3075 ce->lrc_desc |= CTX_DESC_FORCE_RESTORE;
3078 static const struct intel_context_ops execlists_context_ops = {
3079 .alloc = execlists_context_alloc,
3081 .pin = execlists_context_pin,
3082 .unpin = execlists_context_unpin,
3084 .enter = intel_context_enter_engine,
3085 .exit = intel_context_exit_engine,
3087 .reset = execlists_context_reset,
3088 .destroy = execlists_context_destroy,
3091 static int gen8_emit_init_breadcrumb(struct i915_request *rq)
3095 if (!i915_request_timeline(rq)->has_initial_breadcrumb)
3098 cs = intel_ring_begin(rq, 6);
3103 * Check if we have been preempted before we even get started.
3105 * After this point i915_request_started() reports true, even if
3106 * we get preempted and so are no longer running.
3108 *cs++ = MI_ARB_CHECK;
3111 *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
3112 *cs++ = i915_request_timeline(rq)->hwsp_offset;
3114 *cs++ = rq->fence.seqno - 1;
3116 intel_ring_advance(rq, cs);
3118 /* Record the updated position of the request's payload */
3119 rq->infix = intel_ring_offset(rq, cs);
3124 static int execlists_request_alloc(struct i915_request *request)
3128 GEM_BUG_ON(!intel_context_is_pinned(request->context));
3131 * Flush enough space to reduce the likelihood of waiting after
3132 * we start building the request - in which case we will just
3133 * have to repeat work.
3135 request->reserved_space += EXECLISTS_REQUEST_SIZE;
3138 * Note that after this point, we have committed to using
3139 * this request as it is being used to both track the
3140 * state of engine initialisation and liveness of the
3141 * golden renderstate above. Think twice before you try
3142 * to cancel/unwind this request now.
3145 /* Unconditionally invalidate GPU caches and TLBs. */
3146 ret = request->engine->emit_flush(request, EMIT_INVALIDATE);
3150 request->reserved_space -= EXECLISTS_REQUEST_SIZE;
3155 * In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after
3156 * PIPE_CONTROL instruction. This is required for the flush to happen correctly
3157 * but there is a slight complication as this is applied in WA batch where the
3158 * values are only initialized once so we cannot take register value at the
3159 * beginning and reuse it further; hence we save its value to memory, upload a
3160 * constant value with bit21 set and then we restore it back with the saved value.
3161 * To simplify the WA, a constant value is formed by using the default value
3162 * of this register. This shouldn't be a problem because we are only modifying
3163 * it for a short period and this batch in non-premptible. We can ofcourse
3164 * use additional instructions that read the actual value of the register
3165 * at that time and set our bit of interest but it makes the WA complicated.
3167 * This WA is also required for Gen9 so extracting as a function avoids
3171 gen8_emit_flush_coherentl3_wa(struct intel_engine_cs *engine, u32 *batch)
3173 /* NB no one else is allowed to scribble over scratch + 256! */
3174 *batch++ = MI_STORE_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT;
3175 *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
3176 *batch++ = intel_gt_scratch_offset(engine->gt,
3177 INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA);
3180 *batch++ = MI_LOAD_REGISTER_IMM(1);
3181 *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
3182 *batch++ = 0x40400000 | GEN8_LQSC_FLUSH_COHERENT_LINES;
3184 batch = gen8_emit_pipe_control(batch,
3185 PIPE_CONTROL_CS_STALL |
3186 PIPE_CONTROL_DC_FLUSH_ENABLE,
3189 *batch++ = MI_LOAD_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT;
3190 *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
3191 *batch++ = intel_gt_scratch_offset(engine->gt,
3192 INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA);
3199 * Typically we only have one indirect_ctx and per_ctx batch buffer which are
3200 * initialized at the beginning and shared across all contexts but this field
3201 * helps us to have multiple batches at different offsets and select them based
3202 * on a criteria. At the moment this batch always start at the beginning of the page
3203 * and at this point we don't have multiple wa_ctx batch buffers.
3205 * The number of WA applied are not known at the beginning; we use this field
3206 * to return the no of DWORDS written.
3208 * It is to be noted that this batch does not contain MI_BATCH_BUFFER_END
3209 * so it adds NOOPs as padding to make it cacheline aligned.
3210 * MI_BATCH_BUFFER_END will be added to perctx batch and both of them together
3211 * makes a complete batch buffer.
3213 static u32 *gen8_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
3215 /* WaDisableCtxRestoreArbitration:bdw,chv */
3216 *batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
3218 /* WaFlushCoherentL3CacheLinesAtContextSwitch:bdw */
3219 if (IS_BROADWELL(engine->i915))
3220 batch = gen8_emit_flush_coherentl3_wa(engine, batch);
3222 /* WaClearSlmSpaceAtContextSwitch:bdw,chv */
3223 /* Actual scratch location is at 128 bytes offset */
3224 batch = gen8_emit_pipe_control(batch,
3225 PIPE_CONTROL_FLUSH_L3 |
3226 PIPE_CONTROL_STORE_DATA_INDEX |
3227 PIPE_CONTROL_CS_STALL |
3228 PIPE_CONTROL_QW_WRITE,
3229 LRC_PPHWSP_SCRATCH_ADDR);
3231 *batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
3233 /* Pad to end of cacheline */
3234 while ((unsigned long)batch % CACHELINE_BYTES)
3238 * MI_BATCH_BUFFER_END is not required in Indirect ctx BB because
3239 * execution depends on the length specified in terms of cache lines
3240 * in the register CTX_RCS_INDIRECT_CTX
3251 static u32 *emit_lri(u32 *batch, const struct lri *lri, unsigned int count)
3253 GEM_BUG_ON(!count || count > 63);
3255 *batch++ = MI_LOAD_REGISTER_IMM(count);
3257 *batch++ = i915_mmio_reg_offset(lri->reg);
3258 *batch++ = lri->value;
3259 } while (lri++, --count);
3265 static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
3267 static const struct lri lri[] = {
3268 /* WaDisableGatherAtSetShaderCommonSlice:skl,bxt,kbl,glk */
3270 COMMON_SLICE_CHICKEN2,
3271 __MASKED_FIELD(GEN9_DISABLE_GATHER_AT_SET_SHADER_COMMON_SLICE,
3278 __MASKED_FIELD(FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX,
3279 FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX),
3285 __MASKED_FIELD(_3D_CHICKEN_SF_PROVOKING_VERTEX_FIX,
3286 _3D_CHICKEN_SF_PROVOKING_VERTEX_FIX),
3290 *batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
3292 /* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
3293 batch = gen8_emit_flush_coherentl3_wa(engine, batch);
3295 /* WaClearSlmSpaceAtContextSwitch:skl,bxt,kbl,glk,cfl */
3296 batch = gen8_emit_pipe_control(batch,
3297 PIPE_CONTROL_FLUSH_L3 |
3298 PIPE_CONTROL_STORE_DATA_INDEX |
3299 PIPE_CONTROL_CS_STALL |
3300 PIPE_CONTROL_QW_WRITE,
3301 LRC_PPHWSP_SCRATCH_ADDR);
3303 batch = emit_lri(batch, lri, ARRAY_SIZE(lri));
3305 /* WaMediaPoolStateCmdInWABB:bxt,glk */
3306 if (HAS_POOLED_EU(engine->i915)) {
3308 * EU pool configuration is setup along with golden context
3309 * during context initialization. This value depends on
3310 * device type (2x6 or 3x6) and needs to be updated based
3311 * on which subslice is disabled especially for 2x6
3312 * devices, however it is safe to load default
3313 * configuration of 3x6 device instead of masking off
3314 * corresponding bits because HW ignores bits of a disabled
3315 * subslice and drops down to appropriate config. Please
3316 * see render_state_setup() in i915_gem_render_state.c for
3317 * possible configurations, to avoid duplication they are
3318 * not shown here again.
3320 *batch++ = GEN9_MEDIA_POOL_STATE;
3321 *batch++ = GEN9_MEDIA_POOL_ENABLE;
3322 *batch++ = 0x00777000;
3328 *batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
3330 /* Pad to end of cacheline */
3331 while ((unsigned long)batch % CACHELINE_BYTES)
3338 gen10_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
3343 * WaPipeControlBefore3DStateSamplePattern: cnl
3345 * Ensure the engine is idle prior to programming a
3346 * 3DSTATE_SAMPLE_PATTERN during a context restore.
3348 batch = gen8_emit_pipe_control(batch,
3349 PIPE_CONTROL_CS_STALL,
3352 * WaPipeControlBefore3DStateSamplePattern says we need 4 dwords for
3353 * the PIPE_CONTROL followed by 12 dwords of 0x0, so 16 dwords in
3354 * total. However, a PIPE_CONTROL is 6 dwords long, not 4, which is
3355 * confusing. Since gen8_emit_pipe_control() already advances the
3356 * batch by 6 dwords, we advance the other 10 here, completing a
3357 * cacheline. It's not clear if the workaround requires this padding
3358 * before other commands, or if it's just the regular padding we would
3359 * already have for the workaround bb, so leave it here for now.
3361 for (i = 0; i < 10; i++)
3364 /* Pad to end of cacheline */
3365 while ((unsigned long)batch % CACHELINE_BYTES)
3371 #define CTX_WA_BB_OBJ_SIZE (PAGE_SIZE)
3373 static int lrc_setup_wa_ctx(struct intel_engine_cs *engine)
3375 struct drm_i915_gem_object *obj;
3376 struct i915_vma *vma;
3379 obj = i915_gem_object_create_shmem(engine->i915, CTX_WA_BB_OBJ_SIZE);
3381 return PTR_ERR(obj);
3383 vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
3389 err = i915_ggtt_pin(vma, 0, PIN_HIGH);
3393 engine->wa_ctx.vma = vma;
3397 i915_gem_object_put(obj);
3401 static void lrc_destroy_wa_ctx(struct intel_engine_cs *engine)
3403 i915_vma_unpin_and_release(&engine->wa_ctx.vma, 0);
3406 typedef u32 *(*wa_bb_func_t)(struct intel_engine_cs *engine, u32 *batch);
3408 static int intel_init_workaround_bb(struct intel_engine_cs *engine)
3410 struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx;
3411 struct i915_wa_ctx_bb *wa_bb[2] = { &wa_ctx->indirect_ctx,
3413 wa_bb_func_t wa_bb_fn[2];
3415 void *batch, *batch_ptr;
3419 if (engine->class != RENDER_CLASS)
3422 switch (INTEL_GEN(engine->i915)) {
3427 wa_bb_fn[0] = gen10_init_indirectctx_bb;
3431 wa_bb_fn[0] = gen9_init_indirectctx_bb;
3435 wa_bb_fn[0] = gen8_init_indirectctx_bb;
3439 MISSING_CASE(INTEL_GEN(engine->i915));
3443 ret = lrc_setup_wa_ctx(engine);
3445 DRM_DEBUG_DRIVER("Failed to setup context WA page: %d\n", ret);
3449 page = i915_gem_object_get_dirty_page(wa_ctx->vma->obj, 0);
3450 batch = batch_ptr = kmap_atomic(page);
3453 * Emit the two workaround batch buffers, recording the offset from the
3454 * start of the workaround batch buffer object for each and their
3457 for (i = 0; i < ARRAY_SIZE(wa_bb_fn); i++) {
3458 wa_bb[i]->offset = batch_ptr - batch;
3459 if (GEM_DEBUG_WARN_ON(!IS_ALIGNED(wa_bb[i]->offset,
3460 CACHELINE_BYTES))) {
3465 batch_ptr = wa_bb_fn[i](engine, batch_ptr);
3466 wa_bb[i]->size = batch_ptr - (batch + wa_bb[i]->offset);
3469 BUG_ON(batch_ptr - batch > CTX_WA_BB_OBJ_SIZE);
3471 kunmap_atomic(batch);
3473 lrc_destroy_wa_ctx(engine);
3478 static void enable_error_interrupt(struct intel_engine_cs *engine)
3482 engine->execlists.error_interrupt = 0;
3483 ENGINE_WRITE(engine, RING_EMR, ~0u);
3484 ENGINE_WRITE(engine, RING_EIR, ~0u); /* clear all existing errors */
3486 status = ENGINE_READ(engine, RING_ESR);
3487 if (unlikely(status)) {
3488 dev_err(engine->i915->drm.dev,
3489 "engine '%s' resumed still in error: %08x\n",
3490 engine->name, status);
3491 __intel_gt_reset(engine->gt, engine->mask);
3495 * On current gen8+, we have 2 signals to play with
3497 * - I915_ERROR_INSTUCTION (bit 0)
3499 * Generate an error if the command parser encounters an invalid
3502 * This is a fatal error.
3506 * Generate an error on privilege violation (where the CP replaces
3507 * the instruction with a no-op). This also fires for writes into
3508 * read-only scratch pages.
3510 * This is a non-fatal error, parsing continues.
3512 * * there are a few others defined for odd HW that we do not use
3514 * Since CP_PRIV fires for cases where we have chosen to ignore the
3515 * error (as the HW is validating and suppressing the mistakes), we
3516 * only unmask the instruction error bit.
3518 ENGINE_WRITE(engine, RING_EMR, ~I915_ERROR_INSTRUCTION);
3521 static void enable_execlists(struct intel_engine_cs *engine)
3525 assert_forcewakes_active(engine->uncore, FORCEWAKE_ALL);
3527 intel_engine_set_hwsp_writemask(engine, ~0u); /* HWSTAM */
3529 if (INTEL_GEN(engine->i915) >= 11)
3530 mode = _MASKED_BIT_ENABLE(GEN11_GFX_DISABLE_LEGACY_MODE);
3532 mode = _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE);
3533 ENGINE_WRITE_FW(engine, RING_MODE_GEN7, mode);
3535 ENGINE_WRITE_FW(engine, RING_MI_MODE, _MASKED_BIT_DISABLE(STOP_RING));
3537 ENGINE_WRITE_FW(engine,
3539 i915_ggtt_offset(engine->status_page.vma));
3540 ENGINE_POSTING_READ(engine, RING_HWS_PGA);
3542 enable_error_interrupt(engine);
3544 engine->context_tag = 0;
3547 static bool unexpected_starting_state(struct intel_engine_cs *engine)
3549 bool unexpected = false;
3551 if (ENGINE_READ_FW(engine, RING_MI_MODE) & STOP_RING) {
3552 DRM_DEBUG_DRIVER("STOP_RING still set in RING_MI_MODE\n");
3559 static int execlists_resume(struct intel_engine_cs *engine)
3561 intel_mocs_init_engine(engine);
3563 intel_engine_reset_breadcrumbs(engine);
3565 if (GEM_SHOW_DEBUG() && unexpected_starting_state(engine)) {
3566 struct drm_printer p = drm_debug_printer(__func__);
3568 intel_engine_dump(engine, &p, NULL);
3571 enable_execlists(engine);
3576 static void execlists_reset_prepare(struct intel_engine_cs *engine)
3578 struct intel_engine_execlists * const execlists = &engine->execlists;
3579 unsigned long flags;
3581 ENGINE_TRACE(engine, "depth<-%d\n",
3582 atomic_read(&execlists->tasklet.count));
3585 * Prevent request submission to the hardware until we have
3586 * completed the reset in i915_gem_reset_finish(). If a request
3587 * is completed by one engine, it may then queue a request
3588 * to a second via its execlists->tasklet *just* as we are
3589 * calling engine->resume() and also writing the ELSP.
3590 * Turning off the execlists->tasklet until the reset is over
3591 * prevents the race.
3593 __tasklet_disable_sync_once(&execlists->tasklet);
3594 GEM_BUG_ON(!reset_in_progress(execlists));
3596 /* And flush any current direct submission. */
3597 spin_lock_irqsave(&engine->active.lock, flags);
3598 spin_unlock_irqrestore(&engine->active.lock, flags);
3601 * We stop engines, otherwise we might get failed reset and a
3602 * dead gpu (on elk). Also as modern gpu as kbl can suffer
3603 * from system hang if batchbuffer is progressing when
3604 * the reset is issued, regardless of READY_TO_RESET ack.
3605 * Thus assume it is best to stop engines on all gens
3606 * where we have a gpu reset.
3608 * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
3610 * FIXME: Wa for more modern gens needs to be validated
3612 intel_engine_stop_cs(engine);
3615 static void reset_csb_pointers(struct intel_engine_cs *engine)
3617 struct intel_engine_execlists * const execlists = &engine->execlists;
3618 const unsigned int reset_value = execlists->csb_size - 1;
3620 ring_set_paused(engine, 0);
3623 * After a reset, the HW starts writing into CSB entry [0]. We
3624 * therefore have to set our HEAD pointer back one entry so that
3625 * the *first* entry we check is entry 0. To complicate this further,
3626 * as we don't wait for the first interrupt after reset, we have to
3627 * fake the HW write to point back to the last entry so that our
3628 * inline comparison of our cached head position against the last HW
3629 * write works even before the first interrupt.
3631 execlists->csb_head = reset_value;
3632 WRITE_ONCE(*execlists->csb_write, reset_value);
3633 wmb(); /* Make sure this is visible to HW (paranoia?) */
3636 * Sometimes Icelake forgets to reset its pointers on a GPU reset.
3637 * Bludgeon them with a mmio update to be sure.
3639 ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR,
3640 reset_value << 8 | reset_value);
3641 ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR);
3643 invalidate_csb_entries(&execlists->csb_status[0],
3644 &execlists->csb_status[reset_value]);
3647 static void __reset_stop_ring(u32 *regs, const struct intel_engine_cs *engine)
3651 x = lrc_ring_mi_mode(engine);
3653 regs[x + 1] &= ~STOP_RING;
3654 regs[x + 1] |= STOP_RING << 16;
3658 static void __execlists_reset_reg_state(const struct intel_context *ce,
3659 const struct intel_engine_cs *engine)
3661 u32 *regs = ce->lrc_reg_state;
3663 __reset_stop_ring(regs, engine);
3666 static void __execlists_reset(struct intel_engine_cs *engine, bool stalled)
3668 struct intel_engine_execlists * const execlists = &engine->execlists;
3669 struct intel_context *ce;
3670 struct i915_request *rq;
3673 mb(); /* paranoia: read the CSB pointers from after the reset */
3674 clflush(execlists->csb_write);
3677 process_csb(engine); /* drain preemption events */
3679 /* Following the reset, we need to reload the CSB read/write pointers */
3680 reset_csb_pointers(engine);
3683 * Save the currently executing context, even if we completed
3684 * its request, it was still running at the time of the
3685 * reset and will have been clobbered.
3687 rq = execlists_active(execlists);
3692 GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
3694 if (i915_request_completed(rq)) {
3695 /* Idle context; tidy up the ring so we can restart afresh */
3696 head = intel_ring_wrap(ce->ring, rq->tail);
3700 /* We still have requests in-flight; the engine should be active */
3701 GEM_BUG_ON(!intel_engine_pm_is_awake(engine));
3703 /* Context has requests still in-flight; it should not be idle! */
3704 GEM_BUG_ON(i915_active_is_idle(&ce->active));
3706 rq = active_request(ce->timeline, rq);
3707 head = intel_ring_wrap(ce->ring, rq->head);
3708 GEM_BUG_ON(head == ce->ring->tail);
3711 * If this request hasn't started yet, e.g. it is waiting on a
3712 * semaphore, we need to avoid skipping the request or else we
3713 * break the signaling chain. However, if the context is corrupt
3714 * the request will not restart and we will be stuck with a wedged
3715 * device. It is quite often the case that if we issue a reset
3716 * while the GPU is loading the context image, that the context
3717 * image becomes corrupt.
3719 * Otherwise, if we have not started yet, the request should replay
3720 * perfectly and we do not need to flag the result as being erroneous.
3722 if (!i915_request_started(rq))
3726 * If the request was innocent, we leave the request in the ELSP
3727 * and will try to replay it on restarting. The context image may
3728 * have been corrupted by the reset, in which case we may have
3729 * to service a new GPU hang, but more likely we can continue on
3732 * If the request was guilty, we presume the context is corrupt
3733 * and have to at least restore the RING register in the context
3734 * image back to the expected values to skip over the guilty request.
3736 __i915_request_reset(rq, stalled);
3741 * We want a simple context + ring to execute the breadcrumb update.
3742 * We cannot rely on the context being intact across the GPU hang,
3743 * so clear it and rebuild just what we need for the breadcrumb.
3744 * All pending requests for this context will be zapped, and any
3745 * future request will be after userspace has had the opportunity
3746 * to recreate its own state.
3748 GEM_BUG_ON(!intel_context_is_pinned(ce));
3749 restore_default_state(ce, engine);
3752 ENGINE_TRACE(engine, "replay {head:%04x, tail:%04x}\n",
3753 head, ce->ring->tail);
3754 __execlists_reset_reg_state(ce, engine);
3755 __execlists_update_reg_state(ce, engine, head);
3756 ce->lrc_desc |= CTX_DESC_FORCE_RESTORE; /* paranoid: GPU was reset! */
3759 /* Push back any incomplete requests for replay after the reset. */
3760 cancel_port_requests(execlists);
3761 __unwind_incomplete_requests(engine);
3764 static void execlists_reset_rewind(struct intel_engine_cs *engine, bool stalled)
3766 unsigned long flags;
3768 ENGINE_TRACE(engine, "\n");
3770 spin_lock_irqsave(&engine->active.lock, flags);
3772 __execlists_reset(engine, stalled);
3774 spin_unlock_irqrestore(&engine->active.lock, flags);
3777 static void nop_submission_tasklet(unsigned long data)
3779 struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
3781 /* The driver is wedged; don't process any more events. */
3782 WRITE_ONCE(engine->execlists.queue_priority_hint, INT_MIN);
3785 static void execlists_reset_cancel(struct intel_engine_cs *engine)
3787 struct intel_engine_execlists * const execlists = &engine->execlists;
3788 struct i915_request *rq, *rn;
3790 unsigned long flags;
3792 ENGINE_TRACE(engine, "\n");
3795 * Before we call engine->cancel_requests(), we should have exclusive
3796 * access to the submission state. This is arranged for us by the
3797 * caller disabling the interrupt generation, the tasklet and other
3798 * threads that may then access the same state, giving us a free hand
3799 * to reset state. However, we still need to let lockdep be aware that
3800 * we know this state may be accessed in hardirq context, so we
3801 * disable the irq around this manipulation and we want to keep
3802 * the spinlock focused on its duties and not accidentally conflate
3803 * coverage to the submission's irq state. (Similarly, although we
3804 * shouldn't need to disable irq around the manipulation of the
3805 * submission's irq state, we also wish to remind ourselves that
3808 spin_lock_irqsave(&engine->active.lock, flags);
3810 __execlists_reset(engine, true);
3812 /* Mark all executing requests as skipped. */
3813 list_for_each_entry(rq, &engine->active.requests, sched.link)
3816 /* Flush the queued requests to the timeline list (for retiring). */
3817 while ((rb = rb_first_cached(&execlists->queue))) {
3818 struct i915_priolist *p = to_priolist(rb);
3821 priolist_for_each_request_consume(rq, rn, p, i) {
3823 __i915_request_submit(rq);
3826 rb_erase_cached(&p->node, &execlists->queue);
3827 i915_priolist_free(p);
3830 /* On-hold requests will be flushed to timeline upon their release */
3831 list_for_each_entry(rq, &engine->active.hold, sched.link)
3834 /* Cancel all attached virtual engines */
3835 while ((rb = rb_first_cached(&execlists->virtual))) {
3836 struct virtual_engine *ve =
3837 rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
3839 rb_erase_cached(rb, &execlists->virtual);
3842 spin_lock(&ve->base.active.lock);
3843 rq = fetch_and_zero(&ve->request);
3847 rq->engine = engine;
3848 __i915_request_submit(rq);
3849 i915_request_put(rq);
3851 ve->base.execlists.queue_priority_hint = INT_MIN;
3853 spin_unlock(&ve->base.active.lock);
3856 /* Remaining _unready_ requests will be nop'ed when submitted */
3858 execlists->queue_priority_hint = INT_MIN;
3859 execlists->queue = RB_ROOT_CACHED;
3861 GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet));
3862 execlists->tasklet.func = nop_submission_tasklet;
3864 spin_unlock_irqrestore(&engine->active.lock, flags);
3867 static void execlists_reset_finish(struct intel_engine_cs *engine)
3869 struct intel_engine_execlists * const execlists = &engine->execlists;
3872 * After a GPU reset, we may have requests to replay. Do so now while
3873 * we still have the forcewake to be sure that the GPU is not allowed
3874 * to sleep before we restart and reload a context.
3876 GEM_BUG_ON(!reset_in_progress(execlists));
3877 if (!RB_EMPTY_ROOT(&execlists->queue.rb_root))
3878 execlists->tasklet.func(execlists->tasklet.data);
3880 if (__tasklet_enable(&execlists->tasklet))
3881 /* And kick in case we missed a new request submission. */
3882 tasklet_hi_schedule(&execlists->tasklet);
3883 ENGINE_TRACE(engine, "depth->%d\n",
3884 atomic_read(&execlists->tasklet.count));
3887 static int gen8_emit_bb_start_noarb(struct i915_request *rq,
3888 u64 offset, u32 len,
3889 const unsigned int flags)
3893 cs = intel_ring_begin(rq, 4);
3898 * WaDisableCtxRestoreArbitration:bdw,chv
3900 * We don't need to perform MI_ARB_ENABLE as often as we do (in
3901 * particular all the gen that do not need the w/a at all!), if we
3902 * took care to make sure that on every switch into this context
3903 * (both ordinary and for preemption) that arbitrartion was enabled
3904 * we would be fine. However, for gen8 there is another w/a that
3905 * requires us to not preempt inside GPGPU execution, so we keep
3906 * arbitration disabled for gen8 batches. Arbitration will be
3907 * re-enabled before we close the request
3908 * (engine->emit_fini_breadcrumb).
3910 *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
3912 /* FIXME(BDW+): Address space and security selectors. */
3913 *cs++ = MI_BATCH_BUFFER_START_GEN8 |
3914 (flags & I915_DISPATCH_SECURE ? 0 : BIT(8));
3915 *cs++ = lower_32_bits(offset);
3916 *cs++ = upper_32_bits(offset);
3918 intel_ring_advance(rq, cs);
3923 static int gen8_emit_bb_start(struct i915_request *rq,
3924 u64 offset, u32 len,
3925 const unsigned int flags)
3929 cs = intel_ring_begin(rq, 6);
3933 *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
3935 *cs++ = MI_BATCH_BUFFER_START_GEN8 |
3936 (flags & I915_DISPATCH_SECURE ? 0 : BIT(8));
3937 *cs++ = lower_32_bits(offset);
3938 *cs++ = upper_32_bits(offset);
3940 *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
3943 intel_ring_advance(rq, cs);
3948 static void gen8_logical_ring_enable_irq(struct intel_engine_cs *engine)
3950 ENGINE_WRITE(engine, RING_IMR,
3951 ~(engine->irq_enable_mask | engine->irq_keep_mask));
3952 ENGINE_POSTING_READ(engine, RING_IMR);
3955 static void gen8_logical_ring_disable_irq(struct intel_engine_cs *engine)
3957 ENGINE_WRITE(engine, RING_IMR, ~engine->irq_keep_mask);
3960 static int gen8_emit_flush(struct i915_request *request, u32 mode)
3964 cs = intel_ring_begin(request, 4);
3968 cmd = MI_FLUSH_DW + 1;
3970 /* We always require a command barrier so that subsequent
3971 * commands, such as breadcrumb interrupts, are strictly ordered
3972 * wrt the contents of the write cache being flushed to memory
3973 * (and thus being coherent from the CPU).
3975 cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
3977 if (mode & EMIT_INVALIDATE) {
3978 cmd |= MI_INVALIDATE_TLB;
3979 if (request->engine->class == VIDEO_DECODE_CLASS)
3980 cmd |= MI_INVALIDATE_BSD;
3984 *cs++ = LRC_PPHWSP_SCRATCH_ADDR;
3985 *cs++ = 0; /* upper addr */
3986 *cs++ = 0; /* value */
3987 intel_ring_advance(request, cs);
3992 static int gen8_emit_flush_render(struct i915_request *request,
3995 bool vf_flush_wa = false, dc_flush_wa = false;
3999 flags |= PIPE_CONTROL_CS_STALL;
4001 if (mode & EMIT_FLUSH) {
4002 flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
4003 flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
4004 flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
4005 flags |= PIPE_CONTROL_FLUSH_ENABLE;
4008 if (mode & EMIT_INVALIDATE) {
4009 flags |= PIPE_CONTROL_TLB_INVALIDATE;
4010 flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
4011 flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
4012 flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
4013 flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
4014 flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
4015 flags |= PIPE_CONTROL_QW_WRITE;
4016 flags |= PIPE_CONTROL_STORE_DATA_INDEX;
4019 * On GEN9: before VF_CACHE_INVALIDATE we need to emit a NULL
4022 if (IS_GEN(request->i915, 9))
4025 /* WaForGAMHang:kbl */
4026 if (IS_KBL_REVID(request->i915, 0, KBL_REVID_B0))
4038 cs = intel_ring_begin(request, len);
4043 cs = gen8_emit_pipe_control(cs, 0, 0);
4046 cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_DC_FLUSH_ENABLE,
4049 cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
4052 cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_CS_STALL, 0);
4054 intel_ring_advance(request, cs);
4059 static int gen11_emit_flush_render(struct i915_request *request,
4062 if (mode & EMIT_FLUSH) {
4066 flags |= PIPE_CONTROL_CS_STALL;
4068 flags |= PIPE_CONTROL_TILE_CACHE_FLUSH;
4069 flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
4070 flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
4071 flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
4072 flags |= PIPE_CONTROL_FLUSH_ENABLE;
4073 flags |= PIPE_CONTROL_QW_WRITE;
4074 flags |= PIPE_CONTROL_STORE_DATA_INDEX;
4076 cs = intel_ring_begin(request, 6);
4080 cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
4081 intel_ring_advance(request, cs);
4084 if (mode & EMIT_INVALIDATE) {
4088 flags |= PIPE_CONTROL_CS_STALL;
4090 flags |= PIPE_CONTROL_COMMAND_CACHE_INVALIDATE;
4091 flags |= PIPE_CONTROL_TLB_INVALIDATE;
4092 flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
4093 flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
4094 flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
4095 flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
4096 flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
4097 flags |= PIPE_CONTROL_QW_WRITE;
4098 flags |= PIPE_CONTROL_STORE_DATA_INDEX;
4100 cs = intel_ring_begin(request, 6);
4104 cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
4105 intel_ring_advance(request, cs);
4111 static u32 preparser_disable(bool state)
4113 return MI_ARB_CHECK | 1 << 8 | state;
4116 static int gen12_emit_flush_render(struct i915_request *request,
4119 if (mode & EMIT_FLUSH) {
4123 flags |= PIPE_CONTROL_TILE_CACHE_FLUSH;
4124 flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
4125 flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
4126 /* Wa_1409600907:tgl */
4127 flags |= PIPE_CONTROL_DEPTH_STALL;
4128 flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
4129 flags |= PIPE_CONTROL_FLUSH_ENABLE;
4130 flags |= PIPE_CONTROL_HDC_PIPELINE_FLUSH;
4132 flags |= PIPE_CONTROL_STORE_DATA_INDEX;
4133 flags |= PIPE_CONTROL_QW_WRITE;
4135 flags |= PIPE_CONTROL_CS_STALL;
4137 cs = intel_ring_begin(request, 6);
4141 cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
4142 intel_ring_advance(request, cs);
4145 if (mode & EMIT_INVALIDATE) {
4149 flags |= PIPE_CONTROL_COMMAND_CACHE_INVALIDATE;
4150 flags |= PIPE_CONTROL_TLB_INVALIDATE;
4151 flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
4152 flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
4153 flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
4154 flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
4155 flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
4156 flags |= PIPE_CONTROL_L3_RO_CACHE_INVALIDATE;
4158 flags |= PIPE_CONTROL_STORE_DATA_INDEX;
4159 flags |= PIPE_CONTROL_QW_WRITE;
4161 flags |= PIPE_CONTROL_CS_STALL;
4163 cs = intel_ring_begin(request, 8);
4168 * Prevent the pre-parser from skipping past the TLB
4169 * invalidate and loading a stale page for the batch
4170 * buffer / request payload.
4172 *cs++ = preparser_disable(true);
4174 cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
4176 *cs++ = preparser_disable(false);
4177 intel_ring_advance(request, cs);
4184 * Reserve space for 2 NOOPs at the end of each request to be
4185 * used as a workaround for not being allowed to do lite
4186 * restore with HEAD==TAIL (WaIdleLiteRestore).
4188 static u32 *gen8_emit_wa_tail(struct i915_request *request, u32 *cs)
4190 /* Ensure there's always at least one preemption point per-request. */
4191 *cs++ = MI_ARB_CHECK;
4193 request->wa_tail = intel_ring_offset(request, cs);
4198 static u32 *emit_preempt_busywait(struct i915_request *request, u32 *cs)
4200 *cs++ = MI_SEMAPHORE_WAIT |
4201 MI_SEMAPHORE_GLOBAL_GTT |
4203 MI_SEMAPHORE_SAD_EQ_SDD;
4205 *cs++ = intel_hws_preempt_address(request->engine);
4211 static __always_inline u32*
4212 gen8_emit_fini_breadcrumb_footer(struct i915_request *request,
4215 *cs++ = MI_USER_INTERRUPT;
4217 *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
4218 if (intel_engine_has_semaphores(request->engine))
4219 cs = emit_preempt_busywait(request, cs);
4221 request->tail = intel_ring_offset(request, cs);
4222 assert_ring_tail_valid(request->ring, request->tail);
4224 return gen8_emit_wa_tail(request, cs);
4227 static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
4229 cs = gen8_emit_ggtt_write(cs,
4230 request->fence.seqno,
4231 i915_request_active_timeline(request)->hwsp_offset,
4234 return gen8_emit_fini_breadcrumb_footer(request, cs);
4237 static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
4239 cs = gen8_emit_pipe_control(cs,
4240 PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
4241 PIPE_CONTROL_DEPTH_CACHE_FLUSH |
4242 PIPE_CONTROL_DC_FLUSH_ENABLE,
4245 /* XXX flush+write+CS_STALL all in one upsets gem_concurrent_blt:kbl */
4246 cs = gen8_emit_ggtt_write_rcs(cs,
4247 request->fence.seqno,
4248 i915_request_active_timeline(request)->hwsp_offset,
4249 PIPE_CONTROL_FLUSH_ENABLE |
4250 PIPE_CONTROL_CS_STALL);
4252 return gen8_emit_fini_breadcrumb_footer(request, cs);
4256 gen11_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
4258 cs = gen8_emit_ggtt_write_rcs(cs,
4259 request->fence.seqno,
4260 i915_request_active_timeline(request)->hwsp_offset,
4261 PIPE_CONTROL_CS_STALL |
4262 PIPE_CONTROL_TILE_CACHE_FLUSH |
4263 PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
4264 PIPE_CONTROL_DEPTH_CACHE_FLUSH |
4265 PIPE_CONTROL_DC_FLUSH_ENABLE |
4266 PIPE_CONTROL_FLUSH_ENABLE);
4268 return gen8_emit_fini_breadcrumb_footer(request, cs);
4272 * Note that the CS instruction pre-parser will not stall on the breadcrumb
4273 * flush and will continue pre-fetching the instructions after it before the
4274 * memory sync is completed. On pre-gen12 HW, the pre-parser will stop at
4275 * BB_START/END instructions, so, even though we might pre-fetch the pre-amble
4276 * of the next request before the memory has been flushed, we're guaranteed that
4277 * we won't access the batch itself too early.
4278 * However, on gen12+ the parser can pre-fetch across the BB_START/END commands,
4279 * so, if the current request is modifying an instruction in the next request on
4280 * the same intel_context, we might pre-fetch and then execute the pre-update
4281 * instruction. To avoid this, the users of self-modifying code should either
4282 * disable the parser around the code emitting the memory writes, via a new flag
4283 * added to MI_ARB_CHECK, or emit the writes from a different intel_context. For
4284 * the in-kernel use-cases we've opted to use a separate context, see
4285 * reloc_gpu() as an example.
4286 * All the above applies only to the instructions themselves. Non-inline data
4287 * used by the instructions is not pre-fetched.
4290 static u32 *gen12_emit_preempt_busywait(struct i915_request *request, u32 *cs)
4292 *cs++ = MI_SEMAPHORE_WAIT_TOKEN |
4293 MI_SEMAPHORE_GLOBAL_GTT |
4295 MI_SEMAPHORE_SAD_EQ_SDD;
4297 *cs++ = intel_hws_preempt_address(request->engine);
4305 static __always_inline u32*
4306 gen12_emit_fini_breadcrumb_footer(struct i915_request *request, u32 *cs)
4308 *cs++ = MI_USER_INTERRUPT;
4310 *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
4311 if (intel_engine_has_semaphores(request->engine))
4312 cs = gen12_emit_preempt_busywait(request, cs);
4314 request->tail = intel_ring_offset(request, cs);
4315 assert_ring_tail_valid(request->ring, request->tail);
4317 return gen8_emit_wa_tail(request, cs);
4320 static u32 *gen12_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
4322 cs = gen8_emit_ggtt_write(cs,
4323 request->fence.seqno,
4324 i915_request_active_timeline(request)->hwsp_offset,
4327 return gen12_emit_fini_breadcrumb_footer(request, cs);
4331 gen12_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
4333 cs = gen8_emit_ggtt_write_rcs(cs,
4334 request->fence.seqno,
4335 i915_request_active_timeline(request)->hwsp_offset,
4336 PIPE_CONTROL_CS_STALL |
4337 PIPE_CONTROL_TILE_CACHE_FLUSH |
4338 PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
4339 PIPE_CONTROL_DEPTH_CACHE_FLUSH |
4340 /* Wa_1409600907:tgl */
4341 PIPE_CONTROL_DEPTH_STALL |
4342 PIPE_CONTROL_DC_FLUSH_ENABLE |
4343 PIPE_CONTROL_FLUSH_ENABLE |
4344 PIPE_CONTROL_HDC_PIPELINE_FLUSH);
4346 return gen12_emit_fini_breadcrumb_footer(request, cs);
4349 static void execlists_park(struct intel_engine_cs *engine)
4351 cancel_timer(&engine->execlists.timer);
4352 cancel_timer(&engine->execlists.preempt);
4355 void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
4357 engine->submit_request = execlists_submit_request;
4358 engine->schedule = i915_schedule;
4359 engine->execlists.tasklet.func = execlists_submission_tasklet;
4361 engine->reset.prepare = execlists_reset_prepare;
4362 engine->reset.rewind = execlists_reset_rewind;
4363 engine->reset.cancel = execlists_reset_cancel;
4364 engine->reset.finish = execlists_reset_finish;
4366 engine->park = execlists_park;
4367 engine->unpark = NULL;
4369 engine->flags |= I915_ENGINE_SUPPORTS_STATS;
4370 if (!intel_vgpu_active(engine->i915)) {
4371 engine->flags |= I915_ENGINE_HAS_SEMAPHORES;
4372 if (HAS_LOGICAL_RING_PREEMPTION(engine->i915))
4373 engine->flags |= I915_ENGINE_HAS_PREEMPTION;
4376 if (INTEL_GEN(engine->i915) >= 12)
4377 engine->flags |= I915_ENGINE_HAS_RELATIVE_MMIO;
4379 if (intel_engine_has_preemption(engine))
4380 engine->emit_bb_start = gen8_emit_bb_start;
4382 engine->emit_bb_start = gen8_emit_bb_start_noarb;
4385 static void execlists_shutdown(struct intel_engine_cs *engine)
4387 /* Synchronise with residual timers and any softirq they raise */
4388 del_timer_sync(&engine->execlists.timer);
4389 del_timer_sync(&engine->execlists.preempt);
4390 tasklet_kill(&engine->execlists.tasklet);
4393 static void execlists_release(struct intel_engine_cs *engine)
4395 execlists_shutdown(engine);
4397 intel_engine_cleanup_common(engine);
4398 lrc_destroy_wa_ctx(engine);
4402 logical_ring_default_vfuncs(struct intel_engine_cs *engine)
4404 /* Default vfuncs which can be overriden by each engine. */
4406 engine->resume = execlists_resume;
4408 engine->cops = &execlists_context_ops;
4409 engine->request_alloc = execlists_request_alloc;
4411 engine->emit_flush = gen8_emit_flush;
4412 engine->emit_init_breadcrumb = gen8_emit_init_breadcrumb;
4413 engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb;
4414 if (INTEL_GEN(engine->i915) >= 12)
4415 engine->emit_fini_breadcrumb = gen12_emit_fini_breadcrumb;
4417 engine->set_default_submission = intel_execlists_set_default_submission;
4419 if (INTEL_GEN(engine->i915) < 11) {
4420 engine->irq_enable = gen8_logical_ring_enable_irq;
4421 engine->irq_disable = gen8_logical_ring_disable_irq;
4424 * TODO: On Gen11 interrupt masks need to be clear
4425 * to allow C6 entry. Keep interrupts enabled at
4426 * and take the hit of generating extra interrupts
4427 * until a more refined solution exists.
4433 logical_ring_default_irqs(struct intel_engine_cs *engine)
4435 unsigned int shift = 0;
4437 if (INTEL_GEN(engine->i915) < 11) {
4438 const u8 irq_shifts[] = {
4439 [RCS0] = GEN8_RCS_IRQ_SHIFT,
4440 [BCS0] = GEN8_BCS_IRQ_SHIFT,
4441 [VCS0] = GEN8_VCS0_IRQ_SHIFT,
4442 [VCS1] = GEN8_VCS1_IRQ_SHIFT,
4443 [VECS0] = GEN8_VECS_IRQ_SHIFT,
4446 shift = irq_shifts[engine->id];
4449 engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << shift;
4450 engine->irq_keep_mask = GT_CONTEXT_SWITCH_INTERRUPT << shift;
4451 engine->irq_keep_mask |= GT_CS_MASTER_ERROR_INTERRUPT << shift;
4454 static void rcs_submission_override(struct intel_engine_cs *engine)
4456 switch (INTEL_GEN(engine->i915)) {
4458 engine->emit_flush = gen12_emit_flush_render;
4459 engine->emit_fini_breadcrumb = gen12_emit_fini_breadcrumb_rcs;
4462 engine->emit_flush = gen11_emit_flush_render;
4463 engine->emit_fini_breadcrumb = gen11_emit_fini_breadcrumb_rcs;
4466 engine->emit_flush = gen8_emit_flush_render;
4467 engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb_rcs;
4472 int intel_execlists_submission_setup(struct intel_engine_cs *engine)
4474 struct intel_engine_execlists * const execlists = &engine->execlists;
4475 struct drm_i915_private *i915 = engine->i915;
4476 struct intel_uncore *uncore = engine->uncore;
4477 u32 base = engine->mmio_base;
4479 tasklet_init(&engine->execlists.tasklet,
4480 execlists_submission_tasklet, (unsigned long)engine);
4481 timer_setup(&engine->execlists.timer, execlists_timeslice, 0);
4482 timer_setup(&engine->execlists.preempt, execlists_preempt, 0);
4484 logical_ring_default_vfuncs(engine);
4485 logical_ring_default_irqs(engine);
4487 if (engine->class == RENDER_CLASS)
4488 rcs_submission_override(engine);
4490 if (intel_init_workaround_bb(engine))
4492 * We continue even if we fail to initialize WA batch
4493 * because we only expect rare glitches but nothing
4494 * critical to prevent us from using GPU
4496 DRM_ERROR("WA batch buffer initialization failed\n");
4498 if (HAS_LOGICAL_RING_ELSQ(i915)) {
4499 execlists->submit_reg = uncore->regs +
4500 i915_mmio_reg_offset(RING_EXECLIST_SQ_CONTENTS(base));
4501 execlists->ctrl_reg = uncore->regs +
4502 i915_mmio_reg_offset(RING_EXECLIST_CONTROL(base));
4504 execlists->submit_reg = uncore->regs +
4505 i915_mmio_reg_offset(RING_ELSP(base));
4508 execlists->csb_status =
4509 &engine->status_page.addr[I915_HWS_CSB_BUF0_INDEX];
4511 execlists->csb_write =
4512 &engine->status_page.addr[intel_hws_csb_write_index(i915)];
4514 if (INTEL_GEN(i915) < 11)
4515 execlists->csb_size = GEN8_CSB_ENTRIES;
4517 execlists->csb_size = GEN11_CSB_ENTRIES;
4519 reset_csb_pointers(engine);
4521 /* Finally, take ownership and responsibility for cleanup! */
4522 engine->release = execlists_release;
4527 static u32 intel_lr_indirect_ctx_offset(const struct intel_engine_cs *engine)
4529 u32 indirect_ctx_offset;
4531 switch (INTEL_GEN(engine->i915)) {
4533 MISSING_CASE(INTEL_GEN(engine->i915));
4536 indirect_ctx_offset =
4537 GEN12_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
4540 indirect_ctx_offset =
4541 GEN11_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
4544 indirect_ctx_offset =
4545 GEN10_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
4548 indirect_ctx_offset =
4549 GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
4552 indirect_ctx_offset =
4553 GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT;
4557 return indirect_ctx_offset;
4561 static void init_common_reg_state(u32 * const regs,
4562 const struct intel_engine_cs *engine,
4563 const struct intel_ring *ring,
4568 ctl = _MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH);
4569 ctl |= _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);
4571 ctl |= CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT;
4572 if (INTEL_GEN(engine->i915) < 11)
4573 ctl |= _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT |
4574 CTX_CTRL_RS_CTX_ENABLE);
4575 regs[CTX_CONTEXT_CONTROL] = ctl;
4577 regs[CTX_RING_CTL] = RING_CTL_SIZE(ring->size) | RING_VALID;
4580 static void init_wa_bb_reg_state(u32 * const regs,
4581 const struct intel_engine_cs *engine,
4584 const struct i915_ctx_workarounds * const wa_ctx = &engine->wa_ctx;
4586 if (wa_ctx->per_ctx.size) {
4587 const u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma);
4589 regs[pos_bb_per_ctx] =
4590 (ggtt_offset + wa_ctx->per_ctx.offset) | 0x01;
4593 if (wa_ctx->indirect_ctx.size) {
4594 const u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma);
4596 regs[pos_bb_per_ctx + 2] =
4597 (ggtt_offset + wa_ctx->indirect_ctx.offset) |
4598 (wa_ctx->indirect_ctx.size / CACHELINE_BYTES);
4600 regs[pos_bb_per_ctx + 4] =
4601 intel_lr_indirect_ctx_offset(engine) << 6;
4605 static void init_ppgtt_reg_state(u32 *regs, const struct i915_ppgtt *ppgtt)
4607 if (i915_vm_is_4lvl(&ppgtt->vm)) {
4608 /* 64b PPGTT (48bit canonical)
4609 * PDP0_DESCRIPTOR contains the base address to PML4 and
4610 * other PDP Descriptors are ignored.
4612 ASSIGN_CTX_PML4(ppgtt, regs);
4614 ASSIGN_CTX_PDP(ppgtt, regs, 3);
4615 ASSIGN_CTX_PDP(ppgtt, regs, 2);
4616 ASSIGN_CTX_PDP(ppgtt, regs, 1);
4617 ASSIGN_CTX_PDP(ppgtt, regs, 0);
4621 static struct i915_ppgtt *vm_alias(struct i915_address_space *vm)
4623 if (i915_is_ggtt(vm))
4624 return i915_vm_to_ggtt(vm)->alias;
4626 return i915_vm_to_ppgtt(vm);
4629 static void execlists_init_reg_state(u32 *regs,
4630 const struct intel_context *ce,
4631 const struct intel_engine_cs *engine,
4632 const struct intel_ring *ring,
4636 * A context is actually a big batch buffer with several
4637 * MI_LOAD_REGISTER_IMM commands followed by (reg, value) pairs. The
4638 * values we are setting here are only for the first context restore:
4639 * on a subsequent save, the GPU will recreate this batchbuffer with new
4640 * values (including all the missing MI_LOAD_REGISTER_IMM commands that
4641 * we are not initializing here).
4643 * Must keep consistent with virtual_update_register_offsets().
4645 set_offsets(regs, reg_offsets(engine), engine, inhibit);
4647 init_common_reg_state(regs, engine, ring, inhibit);
4648 init_ppgtt_reg_state(regs, vm_alias(ce->vm));
4650 init_wa_bb_reg_state(regs, engine,
4651 INTEL_GEN(engine->i915) >= 12 ?
4652 GEN12_CTX_BB_PER_CTX_PTR :
4653 CTX_BB_PER_CTX_PTR);
4655 __reset_stop_ring(regs, engine);
4659 populate_lr_context(struct intel_context *ce,
4660 struct drm_i915_gem_object *ctx_obj,
4661 struct intel_engine_cs *engine,
4662 struct intel_ring *ring)
4664 bool inhibit = true;
4668 vaddr = i915_gem_object_pin_map(ctx_obj, I915_MAP_WB);
4669 if (IS_ERR(vaddr)) {
4670 ret = PTR_ERR(vaddr);
4671 DRM_DEBUG_DRIVER("Could not map object pages! (%d)\n", ret);
4675 set_redzone(vaddr, engine);
4677 if (engine->default_state) {
4680 defaults = i915_gem_object_pin_map(engine->default_state,
4682 if (IS_ERR(defaults)) {
4683 ret = PTR_ERR(defaults);
4687 memcpy(vaddr, defaults, engine->context_size);
4688 i915_gem_object_unpin_map(engine->default_state);
4689 __set_bit(CONTEXT_VALID_BIT, &ce->flags);
4693 /* Clear the ppHWSP (inc. per-context counters) */
4694 memset(vaddr, 0, PAGE_SIZE);
4697 * The second page of the context object contains some registers which
4698 * must be set up prior to the first execution.
4700 execlists_init_reg_state(vaddr + LRC_STATE_PN * PAGE_SIZE,
4701 ce, engine, ring, inhibit);
4705 __i915_gem_object_flush_map(ctx_obj, 0, engine->context_size);
4706 i915_gem_object_unpin_map(ctx_obj);
4710 static int __execlists_context_alloc(struct intel_context *ce,
4711 struct intel_engine_cs *engine)
4713 struct drm_i915_gem_object *ctx_obj;
4714 struct intel_ring *ring;
4715 struct i915_vma *vma;
4719 GEM_BUG_ON(ce->state);
4720 context_size = round_up(engine->context_size, I915_GTT_PAGE_SIZE);
4722 if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
4723 context_size += I915_GTT_PAGE_SIZE; /* for redzone */
4725 ctx_obj = i915_gem_object_create_shmem(engine->i915, context_size);
4726 if (IS_ERR(ctx_obj))
4727 return PTR_ERR(ctx_obj);
4729 vma = i915_vma_instance(ctx_obj, &engine->gt->ggtt->vm, NULL);
4732 goto error_deref_obj;
4735 if (!ce->timeline) {
4736 struct intel_timeline *tl;
4737 struct i915_vma *hwsp;
4740 * Use the static global HWSP for the kernel context, and
4741 * a dynamically allocated cacheline for everyone else.
4744 if (unlikely(intel_context_is_barrier(ce)))
4745 hwsp = engine->status_page.vma;
4747 tl = intel_timeline_create(engine->gt, hwsp);
4750 goto error_deref_obj;
4756 ring = intel_engine_create_ring(engine, (unsigned long)ce->ring);
4758 ret = PTR_ERR(ring);
4759 goto error_deref_obj;
4762 ret = populate_lr_context(ce, ctx_obj, engine, ring);
4764 DRM_DEBUG_DRIVER("Failed to populate LRC: %d\n", ret);
4765 goto error_ring_free;
4774 intel_ring_put(ring);
4776 i915_gem_object_put(ctx_obj);
4780 static struct list_head *virtual_queue(struct virtual_engine *ve)
4782 return &ve->base.execlists.default_priolist.requests[0];
4785 static void virtual_context_destroy(struct kref *kref)
4787 struct virtual_engine *ve =
4788 container_of(kref, typeof(*ve), context.ref);
4791 GEM_BUG_ON(!list_empty(virtual_queue(ve)));
4792 GEM_BUG_ON(ve->request);
4793 GEM_BUG_ON(ve->context.inflight);
4795 for (n = 0; n < ve->num_siblings; n++) {
4796 struct intel_engine_cs *sibling = ve->siblings[n];
4797 struct rb_node *node = &ve->nodes[sibling->id].rb;
4798 unsigned long flags;
4800 if (RB_EMPTY_NODE(node))
4803 spin_lock_irqsave(&sibling->active.lock, flags);
4805 /* Detachment is lazily performed in the execlists tasklet */
4806 if (!RB_EMPTY_NODE(node))
4807 rb_erase_cached(node, &sibling->execlists.virtual);
4809 spin_unlock_irqrestore(&sibling->active.lock, flags);
4811 GEM_BUG_ON(__tasklet_is_scheduled(&ve->base.execlists.tasklet));
4813 if (ve->context.state)
4814 __execlists_context_fini(&ve->context);
4815 intel_context_fini(&ve->context);
4821 static void virtual_engine_initial_hint(struct virtual_engine *ve)
4826 * Pick a random sibling on starting to help spread the load around.
4828 * New contexts are typically created with exactly the same order
4829 * of siblings, and often started in batches. Due to the way we iterate
4830 * the array of sibling when submitting requests, sibling[0] is
4831 * prioritised for dequeuing. If we make sure that sibling[0] is fairly
4832 * randomised across the system, we also help spread the load by the
4833 * first engine we inspect being different each time.
4835 * NB This does not force us to execute on this engine, it will just
4836 * typically be the first we inspect for submission.
4838 swp = prandom_u32_max(ve->num_siblings);
4842 swap(ve->siblings[swp], ve->siblings[0]);
4843 if (!intel_engine_has_relative_mmio(ve->siblings[0]))
4844 virtual_update_register_offsets(ve->context.lrc_reg_state,
4848 static int virtual_context_alloc(struct intel_context *ce)
4850 struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
4852 return __execlists_context_alloc(ce, ve->siblings[0]);
4855 static int virtual_context_pin(struct intel_context *ce)
4857 struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
4860 /* Note: we must use a real engine class for setting up reg state */
4861 err = __execlists_context_pin(ce, ve->siblings[0]);
4865 virtual_engine_initial_hint(ve);
4869 static void virtual_context_enter(struct intel_context *ce)
4871 struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
4874 for (n = 0; n < ve->num_siblings; n++)
4875 intel_engine_pm_get(ve->siblings[n]);
4877 intel_timeline_enter(ce->timeline);
4880 static void virtual_context_exit(struct intel_context *ce)
4882 struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
4885 intel_timeline_exit(ce->timeline);
4887 for (n = 0; n < ve->num_siblings; n++)
4888 intel_engine_pm_put(ve->siblings[n]);
4891 static const struct intel_context_ops virtual_context_ops = {
4892 .alloc = virtual_context_alloc,
4894 .pin = virtual_context_pin,
4895 .unpin = execlists_context_unpin,
4897 .enter = virtual_context_enter,
4898 .exit = virtual_context_exit,
4900 .destroy = virtual_context_destroy,
4903 static intel_engine_mask_t virtual_submission_mask(struct virtual_engine *ve)
4905 struct i915_request *rq;
4906 intel_engine_mask_t mask;
4908 rq = READ_ONCE(ve->request);
4912 /* The rq is ready for submission; rq->execution_mask is now stable. */
4913 mask = rq->execution_mask;
4914 if (unlikely(!mask)) {
4915 /* Invalid selection, submit to a random engine in error */
4916 i915_request_set_error_once(rq, -ENODEV);
4917 mask = ve->siblings[0]->mask;
4920 ENGINE_TRACE(&ve->base, "rq=%llx:%lld, mask=%x, prio=%d\n",
4921 rq->fence.context, rq->fence.seqno,
4922 mask, ve->base.execlists.queue_priority_hint);
4927 static void virtual_submission_tasklet(unsigned long data)
4929 struct virtual_engine * const ve = (struct virtual_engine *)data;
4930 const int prio = READ_ONCE(ve->base.execlists.queue_priority_hint);
4931 intel_engine_mask_t mask;
4935 mask = virtual_submission_mask(ve);
4937 if (unlikely(!mask))
4940 local_irq_disable();
4941 for (n = 0; READ_ONCE(ve->request) && n < ve->num_siblings; n++) {
4942 struct intel_engine_cs *sibling = ve->siblings[n];
4943 struct ve_node * const node = &ve->nodes[sibling->id];
4944 struct rb_node **parent, *rb;
4947 if (unlikely(!(mask & sibling->mask))) {
4948 if (!RB_EMPTY_NODE(&node->rb)) {
4949 spin_lock(&sibling->active.lock);
4950 rb_erase_cached(&node->rb,
4951 &sibling->execlists.virtual);
4952 RB_CLEAR_NODE(&node->rb);
4953 spin_unlock(&sibling->active.lock);
4958 spin_lock(&sibling->active.lock);
4960 if (!RB_EMPTY_NODE(&node->rb)) {
4962 * Cheat and avoid rebalancing the tree if we can
4963 * reuse this node in situ.
4965 first = rb_first_cached(&sibling->execlists.virtual) ==
4967 if (prio == node->prio || (prio > node->prio && first))
4970 rb_erase_cached(&node->rb, &sibling->execlists.virtual);
4975 parent = &sibling->execlists.virtual.rb_root.rb_node;
4977 struct ve_node *other;
4980 other = rb_entry(rb, typeof(*other), rb);
4981 if (prio > other->prio) {
4982 parent = &rb->rb_left;
4984 parent = &rb->rb_right;
4989 rb_link_node(&node->rb, rb, parent);
4990 rb_insert_color_cached(&node->rb,
4991 &sibling->execlists.virtual,
4995 GEM_BUG_ON(RB_EMPTY_NODE(&node->rb));
4997 if (first && prio > sibling->execlists.queue_priority_hint) {
4998 sibling->execlists.queue_priority_hint = prio;
4999 tasklet_hi_schedule(&sibling->execlists.tasklet);
5002 spin_unlock(&sibling->active.lock);
5007 static void virtual_submit_request(struct i915_request *rq)
5009 struct virtual_engine *ve = to_virtual_engine(rq->engine);
5010 struct i915_request *old;
5011 unsigned long flags;
5013 ENGINE_TRACE(&ve->base, "rq=%llx:%lld\n",
5017 GEM_BUG_ON(ve->base.submit_request != virtual_submit_request);
5019 spin_lock_irqsave(&ve->base.active.lock, flags);
5022 if (old) { /* background completion event from preempt-to-busy */
5023 GEM_BUG_ON(!i915_request_completed(old));
5024 __i915_request_submit(old);
5025 i915_request_put(old);
5028 if (i915_request_completed(rq)) {
5029 __i915_request_submit(rq);
5031 ve->base.execlists.queue_priority_hint = INT_MIN;
5034 ve->base.execlists.queue_priority_hint = rq_prio(rq);
5035 ve->request = i915_request_get(rq);
5037 GEM_BUG_ON(!list_empty(virtual_queue(ve)));
5038 list_move_tail(&rq->sched.link, virtual_queue(ve));
5040 tasklet_schedule(&ve->base.execlists.tasklet);
5043 spin_unlock_irqrestore(&ve->base.active.lock, flags);
5046 static struct ve_bond *
5047 virtual_find_bond(struct virtual_engine *ve,
5048 const struct intel_engine_cs *master)
5052 for (i = 0; i < ve->num_bonds; i++) {
5053 if (ve->bonds[i].master == master)
5054 return &ve->bonds[i];
5061 virtual_bond_execute(struct i915_request *rq, struct dma_fence *signal)
5063 struct virtual_engine *ve = to_virtual_engine(rq->engine);
5064 intel_engine_mask_t allowed, exec;
5065 struct ve_bond *bond;
5067 allowed = ~to_request(signal)->engine->mask;
5069 bond = virtual_find_bond(ve, to_request(signal)->engine);
5071 allowed &= bond->sibling_mask;
5073 /* Restrict the bonded request to run on only the available engines */
5074 exec = READ_ONCE(rq->execution_mask);
5075 while (!try_cmpxchg(&rq->execution_mask, &exec, exec & allowed))
5078 /* Prevent the master from being re-run on the bonded engines */
5079 to_request(signal)->execution_mask &= ~allowed;
5082 struct intel_context *
5083 intel_execlists_create_virtual(struct intel_engine_cs **siblings,
5086 struct virtual_engine *ve;
5091 return ERR_PTR(-EINVAL);
5094 return intel_context_create(siblings[0]);
5096 ve = kzalloc(struct_size(ve, siblings, count), GFP_KERNEL);
5098 return ERR_PTR(-ENOMEM);
5100 ve->base.i915 = siblings[0]->i915;
5101 ve->base.gt = siblings[0]->gt;
5102 ve->base.uncore = siblings[0]->uncore;
5105 ve->base.class = OTHER_CLASS;
5106 ve->base.uabi_class = I915_ENGINE_CLASS_INVALID;
5107 ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
5108 ve->base.uabi_instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
5111 * The decision on whether to submit a request using semaphores
5112 * depends on the saturated state of the engine. We only compute
5113 * this during HW submission of the request, and we need for this
5114 * state to be globally applied to all requests being submitted
5115 * to this engine. Virtual engines encompass more than one physical
5116 * engine and so we cannot accurately tell in advance if one of those
5117 * engines is already saturated and so cannot afford to use a semaphore
5118 * and be pessimized in priority for doing so -- if we are the only
5119 * context using semaphores after all other clients have stopped, we
5120 * will be starved on the saturated system. Such a global switch for
5121 * semaphores is less than ideal, but alas is the current compromise.
5123 ve->base.saturated = ALL_ENGINES;
5125 snprintf(ve->base.name, sizeof(ve->base.name), "virtual");
5127 intel_engine_init_active(&ve->base, ENGINE_VIRTUAL);
5128 intel_engine_init_breadcrumbs(&ve->base);
5129 intel_engine_init_execlists(&ve->base);
5131 ve->base.cops = &virtual_context_ops;
5132 ve->base.request_alloc = execlists_request_alloc;
5134 ve->base.schedule = i915_schedule;
5135 ve->base.submit_request = virtual_submit_request;
5136 ve->base.bond_execute = virtual_bond_execute;
5138 INIT_LIST_HEAD(virtual_queue(ve));
5139 ve->base.execlists.queue_priority_hint = INT_MIN;
5140 tasklet_init(&ve->base.execlists.tasklet,
5141 virtual_submission_tasklet,
5144 intel_context_init(&ve->context, &ve->base);
5146 for (n = 0; n < count; n++) {
5147 struct intel_engine_cs *sibling = siblings[n];
5149 GEM_BUG_ON(!is_power_of_2(sibling->mask));
5150 if (sibling->mask & ve->base.mask) {
5151 DRM_DEBUG("duplicate %s entry in load balancer\n",
5158 * The virtual engine implementation is tightly coupled to
5159 * the execlists backend -- we push out request directly
5160 * into a tree inside each physical engine. We could support
5161 * layering if we handle cloning of the requests and
5162 * submitting a copy into each backend.
5164 if (sibling->execlists.tasklet.func !=
5165 execlists_submission_tasklet) {
5170 GEM_BUG_ON(RB_EMPTY_NODE(&ve->nodes[sibling->id].rb));
5171 RB_CLEAR_NODE(&ve->nodes[sibling->id].rb);
5173 ve->siblings[ve->num_siblings++] = sibling;
5174 ve->base.mask |= sibling->mask;
5177 * All physical engines must be compatible for their emission
5178 * functions (as we build the instructions during request
5179 * construction and do not alter them before submission
5180 * on the physical engine). We use the engine class as a guide
5181 * here, although that could be refined.
5183 if (ve->base.class != OTHER_CLASS) {
5184 if (ve->base.class != sibling->class) {
5185 DRM_DEBUG("invalid mixing of engine class, sibling %d, already %d\n",
5186 sibling->class, ve->base.class);
5193 ve->base.class = sibling->class;
5194 ve->base.uabi_class = sibling->uabi_class;
5195 snprintf(ve->base.name, sizeof(ve->base.name),
5196 "v%dx%d", ve->base.class, count);
5197 ve->base.context_size = sibling->context_size;
5199 ve->base.emit_bb_start = sibling->emit_bb_start;
5200 ve->base.emit_flush = sibling->emit_flush;
5201 ve->base.emit_init_breadcrumb = sibling->emit_init_breadcrumb;
5202 ve->base.emit_fini_breadcrumb = sibling->emit_fini_breadcrumb;
5203 ve->base.emit_fini_breadcrumb_dw =
5204 sibling->emit_fini_breadcrumb_dw;
5206 ve->base.flags = sibling->flags;
5209 ve->base.flags |= I915_ENGINE_IS_VIRTUAL;
5211 return &ve->context;
5214 intel_context_put(&ve->context);
5215 return ERR_PTR(err);
5218 struct intel_context *
5219 intel_execlists_clone_virtual(struct intel_engine_cs *src)
5221 struct virtual_engine *se = to_virtual_engine(src);
5222 struct intel_context *dst;
5224 dst = intel_execlists_create_virtual(se->siblings,
5229 if (se->num_bonds) {
5230 struct virtual_engine *de = to_virtual_engine(dst->engine);
5232 de->bonds = kmemdup(se->bonds,
5233 sizeof(*se->bonds) * se->num_bonds,
5236 intel_context_put(dst);
5237 return ERR_PTR(-ENOMEM);
5240 de->num_bonds = se->num_bonds;
5246 int intel_virtual_engine_attach_bond(struct intel_engine_cs *engine,
5247 const struct intel_engine_cs *master,
5248 const struct intel_engine_cs *sibling)
5250 struct virtual_engine *ve = to_virtual_engine(engine);
5251 struct ve_bond *bond;
5254 /* Sanity check the sibling is part of the virtual engine */
5255 for (n = 0; n < ve->num_siblings; n++)
5256 if (sibling == ve->siblings[n])
5258 if (n == ve->num_siblings)
5261 bond = virtual_find_bond(ve, master);
5263 bond->sibling_mask |= sibling->mask;
5267 bond = krealloc(ve->bonds,
5268 sizeof(*bond) * (ve->num_bonds + 1),
5273 bond[ve->num_bonds].master = master;
5274 bond[ve->num_bonds].sibling_mask = sibling->mask;
5282 struct intel_engine_cs *
5283 intel_virtual_engine_get_sibling(struct intel_engine_cs *engine,
5284 unsigned int sibling)
5286 struct virtual_engine *ve = to_virtual_engine(engine);
5288 if (sibling >= ve->num_siblings)
5291 return ve->siblings[sibling];
5294 void intel_execlists_show_requests(struct intel_engine_cs *engine,
5295 struct drm_printer *m,
5296 void (*show_request)(struct drm_printer *m,
5297 struct i915_request *rq,
5298 const char *prefix),
5301 const struct intel_engine_execlists *execlists = &engine->execlists;
5302 struct i915_request *rq, *last;
5303 unsigned long flags;
5307 spin_lock_irqsave(&engine->active.lock, flags);
5311 list_for_each_entry(rq, &engine->active.requests, sched.link) {
5312 if (count++ < max - 1)
5313 show_request(m, rq, "\t\tE ");
5320 "\t\t...skipping %d executing requests...\n",
5323 show_request(m, last, "\t\tE ");
5326 if (execlists->switch_priority_hint != INT_MIN)
5327 drm_printf(m, "\t\tSwitch priority hint: %d\n",
5328 READ_ONCE(execlists->switch_priority_hint));
5329 if (execlists->queue_priority_hint != INT_MIN)
5330 drm_printf(m, "\t\tQueue priority hint: %d\n",
5331 READ_ONCE(execlists->queue_priority_hint));
5335 for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) {
5336 struct i915_priolist *p = rb_entry(rb, typeof(*p), node);
5339 priolist_for_each_request(rq, p, i) {
5340 if (count++ < max - 1)
5341 show_request(m, rq, "\t\tQ ");
5349 "\t\t...skipping %d queued requests...\n",
5352 show_request(m, last, "\t\tQ ");
5357 for (rb = rb_first_cached(&execlists->virtual); rb; rb = rb_next(rb)) {
5358 struct virtual_engine *ve =
5359 rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
5360 struct i915_request *rq = READ_ONCE(ve->request);
5363 if (count++ < max - 1)
5364 show_request(m, rq, "\t\tV ");
5372 "\t\t...skipping %d virtual requests...\n",
5375 show_request(m, last, "\t\tV ");
5378 spin_unlock_irqrestore(&engine->active.lock, flags);
5381 void intel_lr_context_reset(struct intel_engine_cs *engine,
5382 struct intel_context *ce,
5386 GEM_BUG_ON(!intel_context_is_pinned(ce));
5389 * We want a simple context + ring to execute the breadcrumb update.
5390 * We cannot rely on the context being intact across the GPU hang,
5391 * so clear it and rebuild just what we need for the breadcrumb.
5392 * All pending requests for this context will be zapped, and any
5393 * future request will be after userspace has had the opportunity
5394 * to recreate its own state.
5397 restore_default_state(ce, engine);
5399 /* Rerun the request; its payload has been neutered (if guilty). */
5400 __execlists_update_reg_state(ce, engine, head);
5404 intel_engine_in_execlists_submission_mode(const struct intel_engine_cs *engine)
5406 return engine->set_default_submission ==
5407 intel_execlists_set_default_submission;
5410 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
5411 #include "selftest_lrc.c"