| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Chris Wilson | 13298 | 83.35% | 225 | 65.79% |
| Matthew Brost | 1122 | 7.03% | 16 | 4.68% |
| Mika Kuoppala | 292 | 1.83% | 9 | 2.63% |
| Stuart Summers | 269 | 1.69% | 1 | 0.29% |
| Umesh Nerlige Ramappa | 167 | 1.05% | 2 | 0.58% |
| Tvrtko A. Ursulin | 119 | 0.75% | 20 | 5.85% |
| Maarten Lankhorst | 117 | 0.73% | 3 | 0.88% |
| Michel Thierry | 84 | 0.53% | 4 | 1.17% |
| Oscar Mateo | 83 | 0.52% | 12 | 3.51% |
| Matt Roper | 69 | 0.43% | 7 | 2.05% |
| Thomas Daniel | 53 | 0.33% | 2 | 0.58% |
| Ville Syrjälä | 53 | 0.33% | 2 | 0.58% |
| Daniele Ceraolo Spurio | 51 | 0.32% | 4 | 1.17% |
| Emil Renner Berthing | 38 | 0.24% | 1 | 0.29% |
| Michael Cheng | 27 | 0.17% | 3 | 0.88% |
| Arun Siluvery | 24 | 0.15% | 4 | 1.17% |
| Lucas De Marchi | 15 | 0.09% | 2 | 0.58% |
| Venkata Sandeep Dhanalakota | 13 | 0.08% | 1 | 0.29% |
| Wambui Karuga | 12 | 0.08% | 1 | 0.29% |
| Lionel Landwerlin | 11 | 0.07% | 2 | 0.58% |
| Thomas Hellstrom | 6 | 0.04% | 2 | 0.58% |
| Jani Nikula | 5 | 0.03% | 3 | 0.88% |
| Alan Previn | 4 | 0.03% | 1 | 0.29% |
| Michał Winiarski | 3 | 0.02% | 2 | 0.58% |
| Imre Deak | 3 | 0.02% | 1 | 0.29% |
| Dave Gordon | 2 | 0.01% | 2 | 0.58% |
| Robert Bragg | 2 | 0.01% | 1 | 0.29% |
| Daniel Vetter | 2 | 0.01% | 1 | 0.29% |
| Akeem G. Abodunrin | 2 | 0.01% | 1 | 0.29% |
| Nick Hoath | 2 | 0.01% | 2 | 0.58% |
| Peter Antoine | 2 | 0.01% | 1 | 0.29% |
| Andrzej Hajda | 1 | 0.01% | 1 | 0.29% |
| Gustavo A. R. Silva | 1 | 0.01% | 1 | 0.29% |
| Julia Lawall | 1 | 0.01% | 1 | 0.29% |
| Michal Wajdeczko | 1 | 0.01% | 1 | 0.29% |
| Total | 15954 | 342 |
// SPDX-License-Identifier: MIT /* * Copyright © 2014 Intel Corporation */ /** * DOC: Logical Rings, Logical Ring Contexts and Execlists * * Motivation: * GEN8 brings an expansion of the HW contexts: "Logical Ring Contexts". * These expanded contexts enable a number of new abilities, especially * "Execlists" (also implemented in this file). * * One of the main differences with the legacy HW contexts is that logical * ring contexts incorporate many more things to the context's state, like * PDPs or ringbuffer control registers: * * The reason why PDPs are included in the context is straightforward: as * PPGTTs (per-process GTTs) are actually per-context, having the PDPs * contained there mean you don't need to do a ppgtt->switch_mm yourself, * instead, the GPU will do it for you on the context switch. * * But, what about the ringbuffer control registers (head, tail, etc..)? * shouldn't we just need a set of those per engine command streamer? This is * where the name "Logical Rings" starts to make sense: by virtualizing the * rings, the engine cs shifts to a new "ring buffer" with every context * switch. When you want to submit a workload to the GPU you: A) choose your * context, B) find its appropriate virtualized ring, C) write commands to it * and then, finally, D) tell the GPU to switch to that context. * * Instead of the legacy MI_SET_CONTEXT, the way you tell the GPU to switch * to a contexts is via a context execution list, ergo "Execlists". * * LRC implementation: * Regarding the creation of contexts, we have: * * - One global default context. * - One local default context for each opened fd. * - One local extra context for each context create ioctl call. * * Now that ringbuffers belong per-context (and not per-engine, like before) * and that contexts are uniquely tied to a given engine (and not reusable, * like before) we need: * * - One ringbuffer per-engine inside each context. * - One backing object per-engine inside each context. * * The global default context starts its life with these new objects fully * allocated and populated. The local default context for each opened fd is * more complex, because we don't know at creation time which engine is going * to use them. To handle this, we have implemented a deferred creation of LR * contexts: * * The local context starts its life as a hollow or blank holder, that only * gets populated for a given engine once we receive an execbuffer. If later * on we receive another execbuffer ioctl for the same context but a different * engine, we allocate/populate a new ringbuffer and context backing object and * so on. * * Finally, regarding local contexts created using the ioctl call: as they are * only allowed with the render ring, we can allocate & populate them right * away (no need to defer anything, at least for now). * * Execlists implementation: * Execlists are the new method by which, on gen8+ hardware, workloads are * submitted for execution (as opposed to the legacy, ringbuffer-based, method). * This method works as follows: * * When a request is committed, its commands (the BB start and any leading or * trailing commands, like the seqno breadcrumbs) are placed in the ringbuffer * for the appropriate context. The tail pointer in the hardware context is not * updated at this time, but instead, kept by the driver in the ringbuffer * structure. A structure representing this request is added to a request queue * for the appropriate engine: this structure contains a copy of the context's * tail after the request was written to the ring buffer and a pointer to the * context itself. * * If the engine's request queue was empty before the request was added, the * queue is processed immediately. Otherwise the queue will be processed during * a context switch interrupt. In any case, elements on the queue will get sent * (in pairs) to the GPU's ExecLists Submit Port (ELSP, for short) with a * globally unique 20-bits submission ID. * * When execution of a request completes, the GPU updates the context status * buffer with a context complete event and generates a context switch interrupt. * During the interrupt handling, the driver examines the events in the buffer: * for each context complete event, if the announced ID matches that on the head * of the request queue, then that request is retired and removed from the queue. * * After processing, if any requests were retired and the queue is not empty * then a new execution list can be submitted. The two requests at the front of * the queue are next to be submitted but since a context may not occur twice in * an execution list, if subsequent requests have the same ID as the first then * the two requests must be combined. This is done simply by discarding requests * at the head of the queue until either only one requests is left (in which case * we use a NULL second context) or the first two requests have unique IDs. * * By always executing the first two requests in the queue the driver ensures * that the GPU is kept as busy as possible. In the case where a single context * completes but a second context is still executing, the request for this second * context will be at the head of the queue when we remove the first one. This * request will then be resubmitted along with a new request for a different context, * which will cause the hardware to continue executing the second request and queue * the new request (the GPU detects the condition of a context getting preempted * with the same context and optimizes the context switch flow by not doing * preemption, but just sampling the new tail pointer). * */ #include <linux/interrupt.h> #include <linux/string_helpers.h> #include "i915_drv.h" #include "i915_trace.h" #include "i915_vgpu.h" #include "gen8_engine_cs.h" #include "intel_breadcrumbs.h" #include "intel_context.h" #include "intel_engine_heartbeat.h" #include "intel_engine_pm.h" #include "intel_engine_regs.h" #include "intel_engine_stats.h" #include "intel_execlists_submission.h" #include "intel_gt.h" #include "intel_gt_irq.h" #include "intel_gt_pm.h" #include "intel_gt_regs.h" #include "intel_gt_requests.h" #include "intel_lrc.h" #include "intel_lrc_reg.h" #include "intel_mocs.h" #include "intel_reset.h" #include "intel_ring.h" #include "intel_workarounds.h" #include "shmem_utils.h" #define RING_EXECLIST_QFULL (1 << 0x2) #define RING_EXECLIST1_VALID (1 << 0x3) #define RING_EXECLIST0_VALID (1 << 0x4) #define RING_EXECLIST_ACTIVE_STATUS (3 << 0xE) #define RING_EXECLIST1_ACTIVE (1 << 0x11) #define RING_EXECLIST0_ACTIVE (1 << 0x12) #define GEN8_CTX_STATUS_IDLE_ACTIVE (1 << 0) #define GEN8_CTX_STATUS_PREEMPTED (1 << 1) #define GEN8_CTX_STATUS_ELEMENT_SWITCH (1 << 2) #define GEN8_CTX_STATUS_ACTIVE_IDLE (1 << 3) #define GEN8_CTX_STATUS_COMPLETE (1 << 4) #define GEN8_CTX_STATUS_LITE_RESTORE (1 << 15) #define GEN8_CTX_STATUS_COMPLETED_MASK \ (GEN8_CTX_STATUS_COMPLETE | GEN8_CTX_STATUS_PREEMPTED) #define GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE (0x1) /* lower csb dword */ #define GEN12_CTX_SWITCH_DETAIL(csb_dw) ((csb_dw) & 0xF) /* upper csb dword */ #define GEN12_CSB_SW_CTX_ID_MASK GENMASK(25, 15) #define GEN12_IDLE_CTX_ID 0x7FF #define GEN12_CSB_CTX_VALID(csb_dw) \ (FIELD_GET(GEN12_CSB_SW_CTX_ID_MASK, csb_dw) != GEN12_IDLE_CTX_ID) #define XEHP_CTX_STATUS_SWITCHED_TO_NEW_QUEUE BIT(1) /* upper csb dword */ #define XEHP_CSB_SW_CTX_ID_MASK GENMASK(31, 10) #define XEHP_IDLE_CTX_ID 0xFFFF #define XEHP_CSB_CTX_VALID(csb_dw) \ (FIELD_GET(XEHP_CSB_SW_CTX_ID_MASK, csb_dw) != XEHP_IDLE_CTX_ID) /* Typical size of the average request (2 pipecontrols and a MI_BB) */ #define EXECLISTS_REQUEST_SIZE 64 /* bytes */ struct virtual_engine { struct intel_engine_cs base; struct intel_context context; struct rcu_work rcu; /* * We allow only a single request through the virtual engine at a time * (each request in the timeline waits for the completion fence of * the previous before being submitted). By restricting ourselves to * only submitting a single request, each request is placed on to a * physical to maximise load spreading (by virtue of the late greedy * scheduling -- each real engine takes the next available request * upon idling). */ struct i915_request *request; /* * We keep a rbtree of available virtual engines inside each physical * engine, sorted by priority. Here we preallocate the nodes we need * for the virtual engine, indexed by physical_engine->id. */ struct ve_node { struct rb_node rb; int prio; } nodes[I915_NUM_ENGINES]; /* And finally, which physical engines this virtual engine maps onto. */ unsigned int num_siblings; struct intel_engine_cs *siblings[]; }; static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine) { GEM_BUG_ON(!intel_engine_is_virtual(engine)); return container_of(engine, struct virtual_engine, base); } static struct intel_context * execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count, unsigned long flags); static struct i915_request * __active_request(const struct intel_timeline * const tl, struct i915_request *rq, int error) { struct i915_request *active = rq; list_for_each_entry_from_reverse(rq, &tl->requests, link) { if (__i915_request_is_complete(rq)) break; if (error) { i915_request_set_error_once(rq, error); __i915_request_skip(rq); } active = rq; } return active; } static struct i915_request * active_request(const struct intel_timeline * const tl, struct i915_request *rq) { return __active_request(tl, rq, 0); } static void ring_set_paused(const struct intel_engine_cs *engine, int state) { /* * We inspect HWS_PREEMPT with a semaphore inside * engine->emit_fini_breadcrumb. If the dword is true, * the ring is paused as the semaphore will busywait * until the dword is false. */ engine->status_page.addr[I915_GEM_HWS_PREEMPT] = state; if (state) wmb(); } static struct i915_priolist *to_priolist(struct rb_node *rb) { return rb_entry(rb, struct i915_priolist, node); } static int rq_prio(const struct i915_request *rq) { return READ_ONCE(rq->sched.attr.priority); } static int effective_prio(const struct i915_request *rq) { int prio = rq_prio(rq); /* * If this request is special and must not be interrupted at any * cost, so be it. Note we are only checking the most recent request * in the context and so may be masking an earlier vip request. It * is hoped that under the conditions where nopreempt is used, this * will not matter (i.e. all requests to that context will be * nopreempt for as long as desired). */ if (i915_request_has_nopreempt(rq)) prio = I915_PRIORITY_UNPREEMPTABLE; return prio; } static int queue_prio(const struct i915_sched_engine *sched_engine) { struct rb_node *rb; rb = rb_first_cached(&sched_engine->queue); if (!rb) return INT_MIN; return to_priolist(rb)->priority; } static int virtual_prio(const struct intel_engine_execlists *el) { struct rb_node *rb = rb_first_cached(&el->virtual); return rb ? rb_entry(rb, struct ve_node, rb)->prio : INT_MIN; } static bool need_preempt(const struct intel_engine_cs *engine, const struct i915_request *rq) { int last_prio; if (!intel_engine_has_semaphores(engine)) return false; /* * Check if the current priority hint merits a preemption attempt. * * We record the highest value priority we saw during rescheduling * prior to this dequeue, therefore we know that if it is strictly * less than the current tail of ESLP[0], we do not need to force * a preempt-to-idle cycle. * * However, the priority hint is a mere hint that we may need to * preempt. If that hint is stale or we may be trying to preempt * ourselves, ignore the request. * * More naturally we would write * prio >= max(0, last); * except that we wish to prevent triggering preemption at the same * priority level: the task that is running should remain running * to preserve FIFO ordering of dependencies. */ last_prio = max(effective_prio(rq), I915_PRIORITY_NORMAL - 1); if (engine->sched_engine->queue_priority_hint <= last_prio) return false; /* * Check against the first request in ELSP[1], it will, thanks to the * power of PI, be the highest priority of that context. */ if (!list_is_last(&rq->sched.link, &engine->sched_engine->requests) && rq_prio(list_next_entry(rq, sched.link)) > last_prio) return true; /* * If the inflight context did not trigger the preemption, then maybe * it was the set of queued requests? Pick the highest priority in * the queue (the first active priolist) and see if it deserves to be * running instead of ELSP[0]. * * The highest priority request in the queue can not be either * ELSP[0] or ELSP[1] as, thanks again to PI, if it was the same * context, it's priority would not exceed ELSP[0] aka last_prio. */ return max(virtual_prio(&engine->execlists), queue_prio(engine->sched_engine)) > last_prio; } __maybe_unused static bool assert_priority_queue(const struct i915_request *prev, const struct i915_request *next) { /* * Without preemption, the prev may refer to the still active element * which we refuse to let go. * * Even with preemption, there are times when we think it is better not * to preempt and leave an ostensibly lower priority request in flight. */ if (i915_request_is_active(prev)) return true; return rq_prio(prev) >= rq_prio(next); } static struct i915_request * __unwind_incomplete_requests(struct intel_engine_cs *engine) { struct i915_request *rq, *rn, *active = NULL; struct list_head *pl; int prio = I915_PRIORITY_INVALID; lockdep_assert_held(&engine->sched_engine->lock); list_for_each_entry_safe_reverse(rq, rn, &engine->sched_engine->requests, sched.link) { if (__i915_request_is_complete(rq)) { list_del_init(&rq->sched.link); continue; } __i915_request_unsubmit(rq); GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID); if (rq_prio(rq) != prio) { prio = rq_prio(rq); pl = i915_sched_lookup_priolist(engine->sched_engine, prio); } GEM_BUG_ON(i915_sched_engine_is_empty(engine->sched_engine)); list_move(&rq->sched.link, pl); set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); /* Check in case we rollback so far we wrap [size/2] */ if (intel_ring_direction(rq->ring, rq->tail, rq->ring->tail + 8) > 0) rq->context->lrc.desc |= CTX_DESC_FORCE_RESTORE; active = rq; } return active; } struct i915_request * execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists) { struct intel_engine_cs *engine = container_of(execlists, typeof(*engine), execlists); return __unwind_incomplete_requests(engine); } static void execlists_context_status_change(struct i915_request *rq, unsigned long status) { /* * Only used when GVT-g is enabled now. When GVT-g is disabled, * The compiler should eliminate this function as dead-code. */ if (!IS_ENABLED(CONFIG_DRM_I915_GVT)) return; atomic_notifier_call_chain(&rq->engine->context_status_notifier, status, rq); } static void reset_active(struct i915_request *rq, struct intel_engine_cs *engine) { struct intel_context * const ce = rq->context; u32 head; /* * The executing context has been cancelled. We want to prevent * further execution along this context and propagate the error on * to anything depending on its results. * * In __i915_request_submit(), we apply the -EIO and remove the * requests' payloads for any banned requests. But first, we must * rewind the context back to the start of the incomplete request so * that we do not jump back into the middle of the batch. * * We preserve the breadcrumbs and semaphores of the incomplete * requests so that inter-timeline dependencies (i.e other timelines) * remain correctly ordered. And we defer to __i915_request_submit() * so that all asynchronous waits are correctly handled. */ ENGINE_TRACE(engine, "{ reset rq=%llx:%lld }\n", rq->fence.context, rq->fence.seqno); /* On resubmission of the active request, payload will be scrubbed */ if (__i915_request_is_complete(rq)) head = rq->tail; else head = __active_request(ce->timeline, rq, -EIO)->head; head = intel_ring_wrap(ce->ring, head); /* Scrub the context image to prevent replaying the previous batch */ lrc_init_regs(ce, engine, true); /* We've switched away, so this should be a no-op, but intent matters */ ce->lrc.lrca = lrc_update_regs(ce, engine, head); } static bool bad_request(const struct i915_request *rq) { return rq->fence.error && i915_request_started(rq); } static struct intel_engine_cs * __execlists_schedule_in(struct i915_request *rq) { struct intel_engine_cs * const engine = rq->engine; struct intel_context * const ce = rq->context; intel_context_get(ce); if (unlikely(intel_context_is_closed(ce) && !intel_engine_has_heartbeat(engine))) intel_context_set_exiting(ce); if (unlikely(!intel_context_is_schedulable(ce) || bad_request(rq))) reset_active(rq, engine); if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) lrc_check_regs(ce, engine, "before"); if (ce->tag) { /* Use a fixed tag for OA and friends */ GEM_BUG_ON(ce->tag <= BITS_PER_LONG); ce->lrc.ccid = ce->tag; } else if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50)) { /* We don't need a strict matching tag, just different values */ unsigned int tag = ffs(READ_ONCE(engine->context_tag)); GEM_BUG_ON(tag == 0 || tag >= BITS_PER_LONG); clear_bit(tag - 1, &engine->context_tag); ce->lrc.ccid = tag << (XEHP_SW_CTX_ID_SHIFT - 32); BUILD_BUG_ON(BITS_PER_LONG > GEN12_MAX_CONTEXT_HW_ID); } else { /* We don't need a strict matching tag, just different values */ unsigned int tag = __ffs(engine->context_tag); GEM_BUG_ON(tag >= BITS_PER_LONG); __clear_bit(tag, &engine->context_tag); ce->lrc.ccid = (1 + tag) << (GEN11_SW_CTX_ID_SHIFT - 32); BUILD_BUG_ON(BITS_PER_LONG > GEN12_MAX_CONTEXT_HW_ID); } ce->lrc.ccid |= engine->execlists.ccid; __intel_gt_pm_get(engine->gt); if (engine->fw_domain && !engine->fw_active++) intel_uncore_forcewake_get(engine->uncore, engine->fw_domain); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); intel_engine_context_in(engine); CE_TRACE(ce, "schedule-in, ccid:%x\n", ce->lrc.ccid); return engine; } static void execlists_schedule_in(struct i915_request *rq, int idx) { struct intel_context * const ce = rq->context; struct intel_engine_cs *old; GEM_BUG_ON(!intel_engine_pm_is_awake(rq->engine)); trace_i915_request_in(rq, idx); old = ce->inflight; if (!old) old = __execlists_schedule_in(rq); WRITE_ONCE(ce->inflight, ptr_inc(old)); GEM_BUG_ON(intel_context_inflight(ce) != rq->engine); } static void resubmit_virtual_request(struct i915_request *rq, struct virtual_engine *ve) { struct intel_engine_cs *engine = rq->engine; spin_lock_irq(&engine->sched_engine->lock); clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); WRITE_ONCE(rq->engine, &ve->base); ve->base.submit_request(rq); spin_unlock_irq(&engine->sched_engine->lock); } static void kick_siblings(struct i915_request *rq, struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); struct intel_engine_cs *engine = rq->engine; /* * After this point, the rq may be transferred to a new sibling, so * before we clear ce->inflight make sure that the context has been * removed from the b->signalers and furthermore we need to make sure * that the concurrent iterator in signal_irq_work is no longer * following ce->signal_link. */ if (!list_empty(&ce->signals)) intel_context_remove_breadcrumbs(ce, engine->breadcrumbs); /* * This engine is now too busy to run this virtual request, so * see if we can find an alternative engine for it to execute on. * Once a request has become bonded to this engine, we treat it the * same as other native request. */ if (i915_request_in_priority_queue(rq) && rq->execution_mask != engine->mask) resubmit_virtual_request(rq, ve); if (READ_ONCE(ve->request)) tasklet_hi_schedule(&ve->base.sched_engine->tasklet); } static void __execlists_schedule_out(struct i915_request * const rq, struct intel_context * const ce) { struct intel_engine_cs * const engine = rq->engine; unsigned int ccid; /* * NB process_csb() is not under the engine->sched_engine->lock and hence * schedule_out can race with schedule_in meaning that we should * refrain from doing non-trivial work here. */ CE_TRACE(ce, "schedule-out, ccid:%x\n", ce->lrc.ccid); GEM_BUG_ON(ce->inflight != engine); if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) lrc_check_regs(ce, engine, "after"); /* * If we have just completed this context, the engine may now be * idle and we want to re-enter powersaving. */ if (intel_timeline_is_last(ce->timeline, rq) && __i915_request_is_complete(rq)) intel_engine_add_retire(engine, ce->timeline); ccid = ce->lrc.ccid; if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50)) { ccid >>= XEHP_SW_CTX_ID_SHIFT - 32; ccid &= XEHP_MAX_CONTEXT_HW_ID; } else { ccid >>= GEN11_SW_CTX_ID_SHIFT - 32; ccid &= GEN12_MAX_CONTEXT_HW_ID; } if (ccid < BITS_PER_LONG) { GEM_BUG_ON(ccid == 0); GEM_BUG_ON(test_bit(ccid - 1, &engine->context_tag)); __set_bit(ccid - 1, &engine->context_tag); } intel_engine_context_out(engine); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT); if (engine->fw_domain && !--engine->fw_active) intel_uncore_forcewake_put(engine->uncore, engine->fw_domain); intel_gt_pm_put_async(engine->gt); /* * If this is part of a virtual engine, its next request may * have been blocked waiting for access to the active context. * We have to kick all the siblings again in case we need to * switch (e.g. the next request is not runnable on this * engine). Hopefully, we will already have submitted the next * request before the tasklet runs and do not need to rebuild * each virtual tree and kick everyone again. */ if (ce->engine != engine) kick_siblings(rq, ce); WRITE_ONCE(ce->inflight, NULL); intel_context_put(ce); } static inline void execlists_schedule_out(struct i915_request *rq) { struct intel_context * const ce = rq->context; trace_i915_request_out(rq); GEM_BUG_ON(!ce->inflight); ce->inflight = ptr_dec(ce->inflight); if (!__intel_context_inflight_count(ce->inflight)) __execlists_schedule_out(rq, ce); i915_request_put(rq); } static u32 map_i915_prio_to_lrc_desc_prio(int prio) { if (prio > I915_PRIORITY_NORMAL) return GEN12_CTX_PRIORITY_HIGH; else if (prio < I915_PRIORITY_NORMAL) return GEN12_CTX_PRIORITY_LOW; else return GEN12_CTX_PRIORITY_NORMAL; } static u64 execlists_update_context(struct i915_request *rq) { struct intel_context *ce = rq->context; u64 desc; u32 tail, prev; desc = ce->lrc.desc; if (rq->engine->flags & I915_ENGINE_HAS_EU_PRIORITY) desc |= map_i915_prio_to_lrc_desc_prio(rq_prio(rq)); /* * WaIdleLiteRestore:bdw,skl * * We should never submit the context with the same RING_TAIL twice * just in case we submit an empty ring, which confuses the HW. * * We append a couple of NOOPs (gen8_emit_wa_tail) after the end of * the normal request to be able to always advance the RING_TAIL on * subsequent resubmissions (for lite restore). Should that fail us, * and we try and submit the same tail again, force the context * reload. * * If we need to return to a preempted context, we need to skip the * lite-restore and force it to reload the RING_TAIL. Otherwise, the * HW has a tendency to ignore us rewinding the TAIL to the end of * an earlier request. */ GEM_BUG_ON(ce->lrc_reg_state[CTX_RING_TAIL] != rq->ring->tail); prev = rq->ring->tail; tail = intel_ring_set_tail(rq->ring, rq->tail); if (unlikely(intel_ring_direction(rq->ring, tail, prev) <= 0)) desc |= CTX_DESC_FORCE_RESTORE; ce->lrc_reg_state[CTX_RING_TAIL] = tail; rq->tail = rq->wa_tail; /* * Make sure the context image is complete before we submit it to HW. * * Ostensibly, writes (including the WCB) should be flushed prior to * an uncached write such as our mmio register access, the empirical * evidence (esp. on Braswell) suggests that the WC write into memory * may not be visible to the HW prior to the completion of the UC * register write and that we may begin execution from the context * before its image is complete leading to invalid PD chasing. */ wmb(); ce->lrc.desc &= ~CTX_DESC_FORCE_RESTORE; return desc; } static void write_desc(struct intel_engine_execlists *execlists, u64 desc, u32 port) { if (execlists->ctrl_reg) { writel(lower_32_bits(desc), execlists->submit_reg + port * 2); writel(upper_32_bits(desc), execlists->submit_reg + port * 2 + 1); } else { writel(upper_32_bits(desc), execlists->submit_reg); writel(lower_32_bits(desc), execlists->submit_reg); } } static __maybe_unused char * dump_port(char *buf, int buflen, const char *prefix, struct i915_request *rq) { if (!rq) return ""; snprintf(buf, buflen, "%sccid:%x %llx:%lld%s prio %d", prefix, rq->context->lrc.ccid, rq->fence.context, rq->fence.seqno, __i915_request_is_complete(rq) ? "!" : __i915_request_has_started(rq) ? "*" : "", rq_prio(rq)); return buf; } static __maybe_unused noinline void trace_ports(const struct intel_engine_execlists *execlists, const char *msg, struct i915_request * const *ports) { const struct intel_engine_cs *engine = container_of(execlists, typeof(*engine), execlists); char __maybe_unused p0[40], p1[40]; if (!ports[0]) return; ENGINE_TRACE(engine, "%s { %s%s }\n", msg, dump_port(p0, sizeof(p0), "", ports[0]), dump_port(p1, sizeof(p1), ", ", ports[1])); } static bool reset_in_progress(const struct intel_engine_cs *engine) { return unlikely(!__tasklet_is_enabled(&engine->sched_engine->tasklet)); } static __maybe_unused noinline bool assert_pending_valid(const struct intel_engine_execlists *execlists, const char *msg) { struct intel_engine_cs *engine = container_of(execlists, typeof(*engine), execlists); struct i915_request * const *port, *rq, *prev = NULL; struct intel_context *ce = NULL; u32 ccid = -1; trace_ports(execlists, msg, execlists->pending); /* We may be messing around with the lists during reset, lalala */ if (reset_in_progress(engine)) return true; if (!execlists->pending[0]) { GEM_TRACE_ERR("%s: Nothing pending for promotion!\n", engine->name); return false; } if (execlists->pending[execlists_num_ports(execlists)]) { GEM_TRACE_ERR("%s: Excess pending[%d] for promotion!\n", engine->name, execlists_num_ports(execlists)); return false; } for (port = execlists->pending; (rq = *port); port++) { unsigned long flags; bool ok = true; GEM_BUG_ON(!kref_read(&rq->fence.refcount)); GEM_BUG_ON(!i915_request_is_active(rq)); if (ce == rq->context) { GEM_TRACE_ERR("%s: Dup context:%llx in pending[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); return false; } ce = rq->context; if (ccid == ce->lrc.ccid) { GEM_TRACE_ERR("%s: Dup ccid:%x context:%llx in pending[%zd]\n", engine->name, ccid, ce->timeline->fence_context, port - execlists->pending); return false; } ccid = ce->lrc.ccid; /* * Sentinels are supposed to be the last request so they flush * the current execution off the HW. Check that they are the only * request in the pending submission. * * NB: Due to the async nature of preempt-to-busy and request * cancellation we need to handle the case where request * becomes a sentinel in parallel to CSB processing. */ if (prev && i915_request_has_sentinel(prev) && !READ_ONCE(prev->fence.error)) { GEM_TRACE_ERR("%s: context:%llx after sentinel in pending[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); return false; } prev = rq; /* * We want virtual requests to only be in the first slot so * that they are never stuck behind a hog and can be immediately * transferred onto the next idle engine. */ if (rq->execution_mask != engine->mask && port != execlists->pending) { GEM_TRACE_ERR("%s: virtual engine:%llx not in prime position[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); return false; } /* Hold tightly onto the lock to prevent concurrent retires! */ if (!spin_trylock_irqsave(&rq->lock, flags)) continue; if (__i915_request_is_complete(rq)) goto unlock; if (i915_active_is_idle(&ce->active) && !intel_context_is_barrier(ce)) { GEM_TRACE_ERR("%s: Inactive context:%llx in pending[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); ok = false; goto unlock; } if (!i915_vma_is_pinned(ce->state)) { GEM_TRACE_ERR("%s: Unpinned context:%llx in pending[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); ok = false; goto unlock; } if (!i915_vma_is_pinned(ce->ring->vma)) { GEM_TRACE_ERR("%s: Unpinned ring:%llx in pending[%zd]\n", engine->name, ce->timeline->fence_context, port - execlists->pending); ok = false; goto unlock; } unlock: spin_unlock_irqrestore(&rq->lock, flags); if (!ok) return false; } return ce; } static void execlists_submit_ports(struct intel_engine_cs *engine) { struct intel_engine_execlists *execlists = &engine->execlists; unsigned int n; GEM_BUG_ON(!assert_pending_valid(execlists, "submit")); /* * We can skip acquiring intel_runtime_pm_get() here as it was taken * on our behalf by the request (see i915_gem_mark_busy()) and it will * not be relinquished until the device is idle (see * i915_gem_idle_work_handler()). As a precaution, we make sure * that all ELSP are drained i.e. we have processed the CSB, * before allowing ourselves to idle and calling intel_runtime_pm_put(). */ GEM_BUG_ON(!intel_engine_pm_is_awake(engine)); /* * ELSQ note: the submit queue is not cleared after being submitted * to the HW so we need to make sure we always clean it up. This is * currently ensured by the fact that we always write the same number * of elsq entries, keep this in mind before changing the loop below. */ for (n = execlists_num_ports(execlists); n--; ) { struct i915_request *rq = execlists->pending[n]; write_desc(execlists, rq ? execlists_update_context(rq) : 0, n); } /* we need to manually load the submit queue */ if (execlists->ctrl_reg) writel(EL_CTRL_LOAD, execlists->ctrl_reg); } static bool ctx_single_port_submission(const struct intel_context *ce) { return (IS_ENABLED(CONFIG_DRM_I915_GVT) && intel_context_force_single_submission(ce)); } static bool can_merge_ctx(const struct intel_context *prev, const struct intel_context *next) { if (prev != next) return false; if (ctx_single_port_submission(prev)) return false; return true; } static unsigned long i915_request_flags(const struct i915_request *rq) { return READ_ONCE(rq->fence.flags); } static bool can_merge_rq(const struct i915_request *prev, const struct i915_request *next) { GEM_BUG_ON(prev == next); GEM_BUG_ON(!assert_priority_queue(prev, next)); /* * We do not submit known completed requests. Therefore if the next * request is already completed, we can pretend to merge it in * with the previous context (and we will skip updating the ELSP * and tracking). Thus hopefully keeping the ELSP full with active * contexts, despite the best efforts of preempt-to-busy to confuse * us. */ if (__i915_request_is_complete(next)) return true; if (unlikely((i915_request_flags(prev) | i915_request_flags(next)) & (BIT(I915_FENCE_FLAG_NOPREEMPT) | BIT(I915_FENCE_FLAG_SENTINEL)))) return false; if (!can_merge_ctx(prev->context, next->context)) return false; GEM_BUG_ON(i915_seqno_passed(prev->fence.seqno, next->fence.seqno)); return true; } static bool virtual_matches(const struct virtual_engine *ve, const struct i915_request *rq, const struct intel_engine_cs *engine) { const struct intel_engine_cs *inflight; if (!rq) return false; if (!(rq->execution_mask & engine->mask)) /* We peeked too soon! */ return false; /* * We track when the HW has completed saving the context image * (i.e. when we have seen the final CS event switching out of * the context) and must not overwrite the context image before * then. This restricts us to only using the active engine * while the previous virtualized request is inflight (so * we reuse the register offsets). This is a very small * hystersis on the greedy seelction algorithm. */ inflight = intel_context_inflight(&ve->context); if (inflight && inflight != engine) return false; return true; } static struct virtual_engine * first_virtual_engine(struct intel_engine_cs *engine) { struct intel_engine_execlists *el = &engine->execlists; struct rb_node *rb = rb_first_cached(&el->virtual); while (rb) { struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); struct i915_request *rq = READ_ONCE(ve->request); /* lazily cleanup after another engine handled rq */ if (!rq || !virtual_matches(ve, rq, engine)) { rb_erase_cached(rb, &el->virtual); RB_CLEAR_NODE(rb); rb = rb_first_cached(&el->virtual); continue; } return ve; } return NULL; } static void virtual_xfer_context(struct virtual_engine *ve, struct intel_engine_cs *engine) { unsigned int n; if (likely(engine == ve->siblings[0])) return; GEM_BUG_ON(READ_ONCE(ve->context.inflight)); if (!intel_engine_has_relative_mmio(engine)) lrc_update_offsets(&ve->context, engine); /* * Move the bound engine to the top of the list for * future execution. We then kick this tasklet first * before checking others, so that we preferentially * reuse this set of bound registers. */ for (n = 1; n < ve->num_siblings; n++) { if (ve->siblings[n] == engine) { swap(ve->siblings[n], ve->siblings[0]); break; } } } static void defer_request(struct i915_request *rq, struct list_head * const pl) { LIST_HEAD(list); /* * We want to move the interrupted request to the back of * the round-robin list (i.e. its priority level), but * in doing so, we must then move all requests that were in * flight and were waiting for the interrupted request to * be run after it again. */ do { struct i915_dependency *p; GEM_BUG_ON(i915_request_is_active(rq)); list_move_tail(&rq->sched.link, pl); for_each_waiter(p, rq) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); if (p->flags & I915_DEPENDENCY_WEAK) continue; /* Leave semaphores spinning on the other engines */ if (w->engine != rq->engine) continue; /* No waiter should start before its signaler */ GEM_BUG_ON(i915_request_has_initial_breadcrumb(w) && __i915_request_has_started(w) && !__i915_request_is_complete(rq)); if (!i915_request_is_ready(w)) continue; if (rq_prio(w) < rq_prio(rq)) continue; GEM_BUG_ON(rq_prio(w) > rq_prio(rq)); GEM_BUG_ON(i915_request_is_active(w)); list_move_tail(&w->sched.link, &list); } rq = list_first_entry_or_null(&list, typeof(*rq), sched.link); } while (rq); } static void defer_active(struct intel_engine_cs *engine) { struct i915_request *rq; rq = __unwind_incomplete_requests(engine); if (!rq) return; defer_request(rq, i915_sched_lookup_priolist(engine->sched_engine, rq_prio(rq))); } static bool timeslice_yield(const struct intel_engine_execlists *el, const struct i915_request *rq) { /* * Once bitten, forever smitten! * * If the active context ever busy-waited on a semaphore, * it will be treated as a hog until the end of its timeslice (i.e. * until it is scheduled out and replaced by a new submission, * possibly even its own lite-restore). The HW only sends an interrupt * on the first miss, and we do know if that semaphore has been * signaled, or even if it is now stuck on another semaphore. Play * safe, yield if it might be stuck -- it will be given a fresh * timeslice in the near future. */ return rq->context->lrc.ccid == READ_ONCE(el->yield); } static bool needs_timeslice(const struct intel_engine_cs *engine, const struct i915_request *rq) { if (!intel_engine_has_timeslices(engine)) return false; /* If not currently active, or about to switch, wait for next event */ if (!rq || __i915_request_is_complete(rq)) return false; /* We do not need to start the timeslice until after the ACK */ if (READ_ONCE(engine->execlists.pending[0])) return false; /* If ELSP[1] is occupied, always check to see if worth slicing */ if (!list_is_last_rcu(&rq->sched.link, &engine->sched_engine->requests)) { ENGINE_TRACE(engine, "timeslice required for second inflight context\n"); return true; } /* Otherwise, ELSP[0] is by itself, but may be waiting in the queue */ if (!i915_sched_engine_is_empty(engine->sched_engine)) { ENGINE_TRACE(engine, "timeslice required for queue\n"); return true; } if (!RB_EMPTY_ROOT(&engine->execlists.virtual.rb_root)) { ENGINE_TRACE(engine, "timeslice required for virtual\n"); return true; } return false; } static bool timeslice_expired(struct intel_engine_cs *engine, const struct i915_request *rq) { const struct intel_engine_execlists *el = &engine->execlists; if (i915_request_has_nopreempt(rq) && __i915_request_has_started(rq)) return false; if (!needs_timeslice(engine, rq)) return false; return timer_expired(&el->timer) || timeslice_yield(el, rq); } static unsigned long timeslice(const struct intel_engine_cs *engine) { return READ_ONCE(engine->props.timeslice_duration_ms); } static void start_timeslice(struct intel_engine_cs *engine) { struct intel_engine_execlists *el = &engine->execlists; unsigned long duration; /* Disable the timer if there is nothing to switch to */ duration = 0; if (needs_timeslice(engine, *el->active)) { /* Avoid continually prolonging an active timeslice */ if (timer_active(&el->timer)) { /* * If we just submitted a new ELSP after an old * context, that context may have already consumed * its timeslice, so recheck. */ if (!timer_pending(&el->timer)) tasklet_hi_schedule(&engine->sched_engine->tasklet); return; } duration = timeslice(engine); } set_timer_ms(&el->timer, duration); } static void record_preemption(struct intel_engine_execlists *execlists) { (void)I915_SELFTEST_ONLY(execlists->preempt_hang.count++); } static unsigned long active_preempt_timeout(struct intel_engine_cs *engine, const struct i915_request *rq) { if (!rq) return 0; /* Only allow ourselves to force reset the currently active context */ engine->execlists.preempt_target = rq; /* Force a fast reset for terminated contexts (ignoring sysfs!) */ if (unlikely(intel_context_is_banned(rq->context) || bad_request(rq))) return INTEL_CONTEXT_BANNED_PREEMPT_TIMEOUT_MS; return READ_ONCE(engine->props.preempt_timeout_ms); } static void set_preempt_timeout(struct intel_engine_cs *engine, const struct i915_request *rq) { if (!intel_engine_has_preempt_reset(engine)) return; set_timer_ms(&engine->execlists.preempt, active_preempt_timeout(engine, rq)); } static bool completed(const struct i915_request *rq) { if (i915_request_has_sentinel(rq)) return false; return __i915_request_is_complete(rq); } static void execlists_dequeue(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct i915_sched_engine * const sched_engine = engine->sched_engine; struct i915_request **port = execlists->pending; struct i915_request ** const last_port = port + execlists->port_mask; struct i915_request *last, * const *active; struct virtual_engine *ve; struct rb_node *rb; bool submit = false; /* * Hardware submission is through 2 ports. Conceptually each port * has a (RING_START, RING_HEAD, RING_TAIL) tuple. RING_START is * static for a context, and unique to each, so we only execute * requests belonging to a single context from each ring. RING_HEAD * is maintained by the CS in the context image, it marks the place * where it got up to last time, and through RING_TAIL we tell the CS * where we want to execute up to this time. * * In this list the requests are in order of execution. Consecutive * requests from the same context are adjacent in the ringbuffer. We * can combine these requests into a single RING_TAIL update: * * RING_HEAD...req1...req2 * ^- RING_TAIL * since to execute req2 the CS must first execute req1. * * Our goal then is to point each port to the end of a consecutive * sequence of requests as being the most optimal (fewest wake ups * and context switches) submission. */ spin_lock(&sched_engine->lock); /* * If the queue is higher priority than the last * request in the currently active context, submit afresh. * We will resubmit again afterwards in case we need to split * the active context to interject the preemption request, * i.e. we will retrigger preemption following the ack in case * of trouble. * */ active = execlists->active; while ((last = *active) && completed(last)) active++; if (last) { if (need_preempt(engine, last)) { ENGINE_TRACE(engine, "preempting last=%llx:%lld, prio=%d, hint=%d\n", last->fence.context, last->fence.seqno, last->sched.attr.priority, sched_engine->queue_priority_hint); record_preemption(execlists); /* * Don't let the RING_HEAD advance past the breadcrumb * as we unwind (and until we resubmit) so that we do * not accidentally tell it to go backwards. */ ring_set_paused(engine, 1); /* * Note that we have not stopped the GPU at this point, * so we are unwinding the incomplete requests as they * remain inflight and so by the time we do complete * the preemption, some of the unwound requests may * complete! */ __unwind_incomplete_requests(engine); last = NULL; } else if (timeslice_expired(engine, last)) { ENGINE_TRACE(engine, "expired:%s last=%llx:%lld, prio=%d, hint=%d, yield?=%s\n", str_yes_no(timer_expired(&execlists->timer)), last->fence.context, last->fence.seqno, rq_prio(last), sched_engine->queue_priority_hint, str_yes_no(timeslice_yield(execlists, last))); /* * Consume this timeslice; ensure we start a new one. * * The timeslice expired, and we will unwind the * running contexts and recompute the next ELSP. * If that submit will be the same pair of contexts * (due to dependency ordering), we will skip the * submission. If we don't cancel the timer now, * we will see that the timer has expired and * reschedule the tasklet; continually until the * next context switch or other preemption event. * * Since we have decided to reschedule based on * consumption of this timeslice, if we submit the * same context again, grant it a full timeslice. */ cancel_timer(&execlists->timer); ring_set_paused(engine, 1); defer_active(engine); /* * Unlike for preemption, if we rewind and continue * executing the same context as previously active, * the order of execution will remain the same and * the tail will only advance. We do not need to * force a full context restore, as a lite-restore * is sufficient to resample the monotonic TAIL. * * If we switch to any other context, similarly we * will not rewind TAIL of current context, and * normal save/restore will preserve state and allow * us to later continue executing the same request. */ last = NULL; } else { /* * Otherwise if we already have a request pending * for execution after the current one, we can * just wait until the next CS event before * queuing more. In either case we will force a * lite-restore preemption event, but if we wait * we hopefully coalesce several updates into a single * submission. */ if (active[1]) { /* * Even if ELSP[1] is occupied and not worthy * of timeslices, our queue might be. */ spin_unlock(&sched_engine->lock); return; } } } /* XXX virtual is always taking precedence */ while ((ve = first_virtual_engine(engine))) { struct i915_request *rq; spin_lock(&ve->base.sched_engine->lock); rq = ve->request; if (unlikely(!virtual_matches(ve, rq, engine))) goto unlock; /* lost the race to a sibling */ GEM_BUG_ON(rq->engine != &ve->base); GEM_BUG_ON(rq->context != &ve->context); if (unlikely(rq_prio(rq) < queue_prio(sched_engine))) { spin_unlock(&ve->base.sched_engine->lock); break; } if (last && !can_merge_rq(last, rq)) { spin_unlock(&ve->base.sched_engine->lock); spin_unlock(&engine->sched_engine->lock); return; /* leave this for another sibling */ } ENGINE_TRACE(engine, "virtual rq=%llx:%lld%s, new engine? %s\n", rq->fence.context, rq->fence.seqno, __i915_request_is_complete(rq) ? "!" : __i915_request_has_started(rq) ? "*" : "", str_yes_no(engine != ve->siblings[0])); WRITE_ONCE(ve->request, NULL); WRITE_ONCE(ve->base.sched_engine->queue_priority_hint, INT_MIN); rb = &ve->nodes[engine->id].rb; rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); GEM_BUG_ON(!(rq->execution_mask & engine->mask)); WRITE_ONCE(rq->engine, engine); if (__i915_request_submit(rq)) { /* * Only after we confirm that we will submit * this request (i.e. it has not already * completed), do we want to update the context. * * This serves two purposes. It avoids * unnecessary work if we are resubmitting an * already completed request after timeslicing. * But more importantly, it prevents us altering * ve->siblings[] on an idle context, where * we may be using ve->siblings[] in * virtual_context_enter / virtual_context_exit. */ virtual_xfer_context(ve, engine); GEM_BUG_ON(ve->siblings[0] != engine); submit = true; last = rq; } i915_request_put(rq); unlock: spin_unlock(&ve->base.sched_engine->lock); /* * Hmm, we have a bunch of virtual engine requests, * but the first one was already completed (thanks * preempt-to-busy!). Keep looking at the veng queue * until we have no more relevant requests (i.e. * the normal submit queue has higher priority). */ if (submit) break; } while ((rb = rb_first_cached(&sched_engine->queue))) { struct i915_priolist *p = to_priolist(rb); struct i915_request *rq, *rn; priolist_for_each_request_consume(rq, rn, p) { bool merge = true; /* * Can we combine this request with the current port? * It has to be the same context/ringbuffer and not * have any exceptions (e.g. GVT saying never to * combine contexts). * * If we can combine the requests, we can execute both * by updating the RING_TAIL to point to the end of the * second request, and so we never need to tell the * hardware about the first. */ if (last && !can_merge_rq(last, rq)) { /* * If we are on the second port and cannot * combine this request with the last, then we * are done. */ if (port == last_port) goto done; /* * We must not populate both ELSP[] with the * same LRCA, i.e. we must submit 2 different * contexts if we submit 2 ELSP. */ if (last->context == rq->context) goto done; if (i915_request_has_sentinel(last)) goto done; /* * We avoid submitting virtual requests into * the secondary ports so that we can migrate * the request immediately to another engine * rather than wait for the primary request. */ if (rq->execution_mask != engine->mask) goto done; /* * If GVT overrides us we only ever submit * port[0], leaving port[1] empty. Note that we * also have to be careful that we don't queue * the same context (even though a different * request) to the second port. */ if (ctx_single_port_submission(last->context) || ctx_single_port_submission(rq->context)) goto done; merge = false; } if (__i915_request_submit(rq)) { if (!merge) { *port++ = i915_request_get(last); last = NULL; } GEM_BUG_ON(last && !can_merge_ctx(last->context, rq->context)); GEM_BUG_ON(last && i915_seqno_passed(last->fence.seqno, rq->fence.seqno)); submit = true; last = rq; } } rb_erase_cached(&p->node, &sched_engine->queue); i915_priolist_free(p); } done: *port++ = i915_request_get(last); /* * Here be a bit of magic! Or sleight-of-hand, whichever you prefer. * * We choose the priority hint such that if we add a request of greater * priority than this, we kick the submission tasklet to decide on * the right order of submitting the requests to hardware. We must * also be prepared to reorder requests as they are in-flight on the * HW. We derive the priority hint then as the first "hole" in * the HW submission ports and if there are no available slots, * the priority of the lowest executing request, i.e. last. * * When we do receive a higher priority request ready to run from the * user, see queue_request(), the priority hint is bumped to that * request triggering preemption on the next dequeue (or subsequent * interrupt for secondary ports). */ sched_engine->queue_priority_hint = queue_prio(sched_engine); i915_sched_engine_reset_on_empty(sched_engine); spin_unlock(&sched_engine->lock); /* * We can skip poking the HW if we ended up with exactly the same set * of requests as currently running, e.g. trying to timeslice a pair * of ordered contexts. */ if (submit && memcmp(active, execlists->pending, (port - execlists->pending) * sizeof(*port))) { *port = NULL; while (port-- != execlists->pending) execlists_schedule_in(*port, port - execlists->pending); WRITE_ONCE(execlists->yield, -1); set_preempt_timeout(engine, *active); execlists_submit_ports(engine); } else { ring_set_paused(engine, 0); while (port-- != execlists->pending) i915_request_put(*port); *execlists->pending = NULL; } } static void execlists_dequeue_irq(struct intel_engine_cs *engine) { local_irq_disable(); /* Suspend interrupts across request submission */ execlists_dequeue(engine); local_irq_enable(); /* flush irq_work (e.g. breadcrumb enabling) */ } static void clear_ports(struct i915_request **ports, int count) { memset_p((void **)ports, NULL, count); } static void copy_ports(struct i915_request **dst, struct i915_request **src, int count) { /* A memcpy_p() would be very useful here! */ while (count--) WRITE_ONCE(*dst++, *src++); /* avoid write tearing */ } static struct i915_request ** cancel_port_requests(struct intel_engine_execlists * const execlists, struct i915_request **inactive) { struct i915_request * const *port; for (port = execlists->pending; *port; port++) *inactive++ = *port; clear_ports(execlists->pending, ARRAY_SIZE(execlists->pending)); /* Mark the end of active before we overwrite *active */ for (port = xchg(&execlists->active, execlists->pending); *port; port++) *inactive++ = *port; clear_ports(execlists->inflight, ARRAY_SIZE(execlists->inflight)); smp_wmb(); /* complete the seqlock for execlists_active() */ WRITE_ONCE(execlists->active, execlists->inflight); /* Having cancelled all outstanding process_csb(), stop their timers */ GEM_BUG_ON(execlists->pending[0]); cancel_timer(&execlists->timer); cancel_timer(&execlists->preempt); return inactive; } /* * Starting with Gen12, the status has a new format: * * bit 0: switched to new queue * bit 1: reserved * bit 2: semaphore wait mode (poll or signal), only valid when * switch detail is set to "wait on semaphore" * bits 3-5: engine class * bits 6-11: engine instance * bits 12-14: reserved * bits 15-25: sw context id of the lrc the GT switched to * bits 26-31: sw counter of the lrc the GT switched to * bits 32-35: context switch detail * - 0: ctx complete * - 1: wait on sync flip * - 2: wait on vblank * - 3: wait on scanline * - 4: wait on semaphore * - 5: context preempted (not on SEMAPHORE_WAIT or * WAIT_FOR_EVENT) * bit 36: reserved * bits 37-43: wait detail (for switch detail 1 to 4) * bits 44-46: reserved * bits 47-57: sw context id of the lrc the GT switched away from * bits 58-63: sw counter of the lrc the GT switched away from * * Xe_HP csb shuffles things around compared to TGL: * * bits 0-3: context switch detail (same possible values as TGL) * bits 4-9: engine instance * bits 10-25: sw context id of the lrc the GT switched to * bits 26-31: sw counter of the lrc the GT switched to * bit 32: semaphore wait mode (poll or signal), Only valid when * switch detail is set to "wait on semaphore" * bit 33: switched to new queue * bits 34-41: wait detail (for switch detail 1 to 4) * bits 42-57: sw context id of the lrc the GT switched away from * bits 58-63: sw counter of the lrc the GT switched away from */ static inline bool __gen12_csb_parse(bool ctx_to_valid, bool ctx_away_valid, bool new_queue, u8 switch_detail) { /* * The context switch detail is not guaranteed to be 5 when a preemption * occurs, so we can't just check for that. The check below works for * all the cases we care about, including preemptions of WAIT * instructions and lite-restore. Preempt-to-idle via the CTRL register * would require some extra handling, but we don't support that. */ if (!ctx_away_valid || new_queue) { GEM_BUG_ON(!ctx_to_valid); return true; } /* * switch detail = 5 is covered by the case above and we do not expect a * context switch on an unsuccessful wait instruction since we always * use polling mode. */ GEM_BUG_ON(switch_detail); return false; } static bool xehp_csb_parse(const u64 csb) { return __gen12_csb_parse(XEHP_CSB_CTX_VALID(lower_32_bits(csb)), /* cxt to */ XEHP_CSB_CTX_VALID(upper_32_bits(csb)), /* cxt away */ upper_32_bits(csb) & XEHP_CTX_STATUS_SWITCHED_TO_NEW_QUEUE, GEN12_CTX_SWITCH_DETAIL(lower_32_bits(csb))); } static bool gen12_csb_parse(const u64 csb) { return __gen12_csb_parse(GEN12_CSB_CTX_VALID(lower_32_bits(csb)), /* cxt to */ GEN12_CSB_CTX_VALID(upper_32_bits(csb)), /* cxt away */ lower_32_bits(csb) & GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE, GEN12_CTX_SWITCH_DETAIL(upper_32_bits(csb))); } static bool gen8_csb_parse(const u64 csb) { return csb & (GEN8_CTX_STATUS_IDLE_ACTIVE | GEN8_CTX_STATUS_PREEMPTED); } static noinline u64 wa_csb_read(const struct intel_engine_cs *engine, u64 * const csb) { u64 entry; /* * Reading from the HWSP has one particular advantage: we can detect * a stale entry. Since the write into HWSP is broken, we have no reason * to trust the HW at all, the mmio entry may equally be unordered, so * we prefer the path that is self-checking and as a last resort, * return the mmio value. * * tgl,dg1:HSDES#22011327657 */ preempt_disable(); if (wait_for_atomic_us((entry = READ_ONCE(*csb)) != -1, 10)) { int idx = csb - engine->execlists.csb_status; int status; status = GEN8_EXECLISTS_STATUS_BUF; if (idx >= 6) { status = GEN11_EXECLISTS_STATUS_BUF2; idx -= 6; } status += sizeof(u64) * idx; entry = intel_uncore_read64(engine->uncore, _MMIO(engine->mmio_base + status)); } preempt_enable(); return entry; } static u64 csb_read(const struct intel_engine_cs *engine, u64 * const csb) { u64 entry = READ_ONCE(*csb); /* * Unfortunately, the GPU does not always serialise its write * of the CSB entries before its write of the CSB pointer, at least * from the perspective of the CPU, using what is known as a Global * Observation Point. We may read a new CSB tail pointer, but then * read the stale CSB entries, causing us to misinterpret the * context-switch events, and eventually declare the GPU hung. * * icl:HSDES#1806554093 * tgl:HSDES#22011248461 */ if (unlikely(entry == -1)) entry = wa_csb_read(engine, csb); /* Consume this entry so that we can spot its future reuse. */ WRITE_ONCE(*csb, -1); /* ELSP is an implicit wmb() before the GPU wraps and overwrites csb */ return entry; } static void new_timeslice(struct intel_engine_execlists *el) { /* By cancelling, we will start afresh in start_timeslice() */ cancel_timer(&el->timer); } static struct i915_request ** process_csb(struct intel_engine_cs *engine, struct i915_request **inactive) { struct intel_engine_execlists * const execlists = &engine->execlists; u64 * const buf = execlists->csb_status; const u8 num_entries = execlists->csb_size; struct i915_request **prev; u8 head, tail; /* * As we modify our execlists state tracking we require exclusive * access. Either we are inside the tasklet, or the tasklet is disabled * and we assume that is only inside the reset paths and so serialised. */ GEM_BUG_ON(!tasklet_is_locked(&engine->sched_engine->tasklet) && !reset_in_progress(engine)); /* * Note that csb_write, csb_status may be either in HWSP or mmio. * When reading from the csb_write mmio register, we have to be * careful to only use the GEN8_CSB_WRITE_PTR portion, which is * the low 4bits. As it happens we know the next 4bits are always * zero and so we can simply masked off the low u8 of the register * and treat it identically to reading from the HWSP (without having * to use explicit shifting and masking, and probably bifurcating * the code to handle the legacy mmio read). */ head = execlists->csb_head; tail = READ_ONCE(*execlists->csb_write); if (unlikely(head == tail)) return inactive; /* * We will consume all events from HW, or at least pretend to. * * The sequence of events from the HW is deterministic, and derived * from our writes to the ELSP, with a smidgen of variability for * the arrival of the asynchronous requests wrt to the inflight * execution. If the HW sends an event that does not correspond with * the one we are expecting, we have to abandon all hope as we lose * all tracking of what the engine is actually executing. We will * only detect we are out of sequence with the HW when we get an * 'impossible' event because we have already drained our own * preemption/promotion queue. If this occurs, we know that we likely * lost track of execution earlier and must unwind and restart, the * simplest way is by stop processing the event queue and force the * engine to reset. */ execlists->csb_head = tail; ENGINE_TRACE(engine, "cs-irq head=%d, tail=%d\n", head, tail); /* * Hopefully paired with a wmb() in HW! * * We must complete the read of the write pointer before any reads * from the CSB, so that we do not see stale values. Without an rmb * (lfence) the HW may speculatively perform the CSB[] reads *before* * we perform the READ_ONCE(*csb_write). */ rmb(); /* Remember who was last running under the timer */ prev = inactive; *prev = NULL; do { bool promote; u64 csb; if (++head == num_entries) head = 0; /* * We are flying near dragons again. * * We hold a reference to the request in execlist_port[] * but no more than that. We are operating in softirq * context and so cannot hold any mutex or sleep. That * prevents us stopping the requests we are processing * in port[] from being retired simultaneously (the * breadcrumb will be complete before we see the * context-switch). As we only hold the reference to the * request, any pointer chasing underneath the request * is subject to a potential use-after-free. Thus we * store all of the bookkeeping within port[] as * required, and avoid using unguarded pointers beneath * request itself. The same applies to the atomic * status notifier. */ csb = csb_read(engine, buf + head); ENGINE_TRACE(engine, "csb[%d]: status=0x%08x:0x%08x\n", head, upper_32_bits(csb), lower_32_bits(csb)); if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50)) promote = xehp_csb_parse(csb); else if (GRAPHICS_VER(engine->i915) >= 12) promote = gen12_csb_parse(csb); else promote = gen8_csb_parse(csb); if (promote) { struct i915_request * const *old = execlists->active; if (GEM_WARN_ON(!*execlists->pending)) { execlists->error_interrupt |= ERROR_CSB; break; } ring_set_paused(engine, 0); /* Point active to the new ELSP; prevent overwriting */ WRITE_ONCE(execlists->active, execlists->pending); smp_wmb(); /* notify execlists_active() */ /* cancel old inflight, prepare for switch */ trace_ports(execlists, "preempted", old); while (*old) *inactive++ = *old++; /* switch pending to inflight */ GEM_BUG_ON(!assert_pending_valid(execlists, "promote")); copy_ports(execlists->inflight, execlists->pending, execlists_num_ports(execlists)); smp_wmb(); /* complete the seqlock */ WRITE_ONCE(execlists->active, execlists->inflight); /* XXX Magic delay for tgl */ ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); WRITE_ONCE(execlists->pending[0], NULL); } else { if (GEM_WARN_ON(!*execlists->active)) { execlists->error_interrupt |= ERROR_CSB; break; } /* port0 completed, advanced to port1 */ trace_ports(execlists, "completed", execlists->active); /* * We rely on the hardware being strongly * ordered, that the breadcrumb write is * coherent (visible from the CPU) before the * user interrupt is processed. One might assume * that the breadcrumb write being before the * user interrupt and the CS event for the context * switch would therefore be before the CS event * itself... */ if (GEM_SHOW_DEBUG() && !__i915_request_is_complete(*execlists->active)) { struct i915_request *rq = *execlists->active; const u32 *regs __maybe_unused = rq->context->lrc_reg_state; ENGINE_TRACE(engine, "context completed before request!\n"); ENGINE_TRACE(engine, "ring:{start:0x%08x, head:%04x, tail:%04x, ctl:%08x, mode:%08x}\n", ENGINE_READ(engine, RING_START), ENGINE_READ(engine, RING_HEAD) & HEAD_ADDR, ENGINE_READ(engine, RING_TAIL) & TAIL_ADDR, ENGINE_READ(engine, RING_CTL), ENGINE_READ(engine, RING_MI_MODE)); ENGINE_TRACE(engine, "rq:{start:%08x, head:%04x, tail:%04x, seqno:%llx:%d, hwsp:%d}, ", i915_ggtt_offset(rq->ring->vma), rq->head, rq->tail, rq->fence.context, lower_32_bits(rq->fence.seqno), hwsp_seqno(rq)); ENGINE_TRACE(engine, "ctx:{start:%08x, head:%04x, tail:%04x}, ", regs[CTX_RING_START], regs[CTX_RING_HEAD], regs[CTX_RING_TAIL]); } *inactive++ = *execlists->active++; GEM_BUG_ON(execlists->active - execlists->inflight > execlists_num_ports(execlists)); } } while (head != tail); /* * Gen11 has proven to fail wrt global observation point between * entry and tail update, failing on the ordering and thus * we see an old entry in the context status buffer. * * Forcibly evict out entries for the next gpu csb update, * to increase the odds that we get a fresh entries with non * working hardware. The cost for doing so comes out mostly with * the wash as hardware, working or not, will need to do the * invalidation before. */ drm_clflush_virt_range(&buf[0], num_entries * sizeof(buf[0])); /* * We assume that any event reflects a change in context flow * and merits a fresh timeslice. We reinstall the timer after * inspecting the queue to see if we need to resumbit. */ if (*prev != *execlists->active) { /* elide lite-restores */ /* * Note the inherent discrepancy between the HW runtime, * recorded as part of the context switch, and the CPU * adjustment for active contexts. We have to hope that * the delay in processing the CS event is very small * and consistent. It works to our advantage to have * the CPU adjustment _undershoot_ (i.e. start later than) * the CS timestamp so we never overreport the runtime * and correct overselves later when updating from HW. */ if (*prev) lrc_runtime_stop((*prev)->context); if (*execlists->active) lrc_runtime_start((*execlists->active)->context); new_timeslice(execlists); } return inactive; } static void post_process_csb(struct i915_request **port, struct i915_request **last) { while (port != last) execlists_schedule_out(*port++); } static void __execlists_hold(struct i915_request *rq) { LIST_HEAD(list); do { struct i915_dependency *p; if (i915_request_is_active(rq)) __i915_request_unsubmit(rq); clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); list_move_tail(&rq->sched.link, &rq->engine->sched_engine->hold); i915_request_set_hold(rq); RQ_TRACE(rq, "on hold\n"); for_each_waiter(p, rq) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); if (p->flags & I915_DEPENDENCY_WEAK) continue; /* Leave semaphores spinning on the other engines */ if (w->engine != rq->engine) continue; if (!i915_request_is_ready(w)) continue; if (__i915_request_is_complete(w)) continue; if (i915_request_on_hold(w)) continue; list_move_tail(&w->sched.link, &list); } rq = list_first_entry_or_null(&list, typeof(*rq), sched.link); } while (rq); } static bool execlists_hold(struct intel_engine_cs *engine, struct i915_request *rq) { if (i915_request_on_hold(rq)) return false; spin_lock_irq(&engine->sched_engine->lock); if (__i915_request_is_complete(rq)) { /* too late! */ rq = NULL; goto unlock; } /* * Transfer this request onto the hold queue to prevent it * being resumbitted to HW (and potentially completed) before we have * released it. Since we may have already submitted following * requests, we need to remove those as well. */ GEM_BUG_ON(i915_request_on_hold(rq)); GEM_BUG_ON(rq->engine != engine); __execlists_hold(rq); GEM_BUG_ON(list_empty(&engine->sched_engine->hold)); unlock: spin_unlock_irq(&engine->sched_engine->lock); return rq; } static bool hold_request(const struct i915_request *rq) { struct i915_dependency *p; bool result = false; /* * If one of our ancestors is on hold, we must also be on hold, * otherwise we will bypass it and execute before it. */ rcu_read_lock(); for_each_signaler(p, rq) { const struct i915_request *s = container_of(p->signaler, typeof(*s), sched); if (s->engine != rq->engine) continue; result = i915_request_on_hold(s); if (result) break; } rcu_read_unlock(); return result; } static void __execlists_unhold(struct i915_request *rq) { LIST_HEAD(list); do { struct i915_dependency *p; RQ_TRACE(rq, "hold release\n"); GEM_BUG_ON(!i915_request_on_hold(rq)); GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit)); i915_request_clear_hold(rq); list_move_tail(&rq->sched.link, i915_sched_lookup_priolist(rq->engine->sched_engine, rq_prio(rq))); set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); /* Also release any children on this engine that are ready */ for_each_waiter(p, rq) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); if (p->flags & I915_DEPENDENCY_WEAK) continue; if (w->engine != rq->engine) continue; if (!i915_request_on_hold(w)) continue; /* Check that no other parents are also on hold */ if (hold_request(w)) continue; list_move_tail(&w->sched.link, &list); } rq = list_first_entry_or_null(&list, typeof(*rq), sched.link); } while (rq); } static void execlists_unhold(struct intel_engine_cs *engine, struct i915_request *rq) { spin_lock_irq(&engine->sched_engine->lock); /* * Move this request back to the priority queue, and all of its * children and grandchildren that were suspended along with it. */ __execlists_unhold(rq); if (rq_prio(rq) > engine->sched_engine->queue_priority_hint) { engine->sched_engine->queue_priority_hint = rq_prio(rq); tasklet_hi_schedule(&engine->sched_engine->tasklet); } spin_unlock_irq(&engine->sched_engine->lock); } struct execlists_capture { struct work_struct work; struct i915_request *rq; struct i915_gpu_coredump *error; }; static void execlists_capture_work(struct work_struct *work) { struct execlists_capture *cap = container_of(work, typeof(*cap), work); const gfp_t gfp = __GFP_KSWAPD_RECLAIM | __GFP_RETRY_MAYFAIL | __GFP_NOWARN; struct intel_engine_cs *engine = cap->rq->engine; struct intel_gt_coredump *gt = cap->error->gt; struct intel_engine_capture_vma *vma; /* Compress all the objects attached to the request, slow! */ vma = intel_engine_coredump_add_request(gt->engine, cap->rq, gfp); if (vma) { struct i915_vma_compress *compress = i915_vma_capture_prepare(gt); intel_engine_coredump_add_vma(gt->engine, vma, compress); i915_vma_capture_finish(gt, compress); } gt->simulated = gt->engine->simulated; cap->error->simulated = gt->simulated; /* Publish the error state, and announce it to the world */ i915_error_state_store(cap->error); i915_gpu_coredump_put(cap->error); /* Return this request and all that depend upon it for signaling */ execlists_unhold(engine, cap->rq); i915_request_put(cap->rq); kfree(cap); } static struct execlists_capture *capture_regs(struct intel_engine_cs *engine) { const gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN; struct execlists_capture *cap; cap = kmalloc(sizeof(*cap), gfp); if (!cap) return NULL; cap->error = i915_gpu_coredump_alloc(engine->i915, gfp); if (!cap->error) goto err_cap; cap->error->gt = intel_gt_coredump_alloc(engine->gt, gfp, CORE_DUMP_FLAG_NONE); if (!cap->error->gt) goto err_gpu; cap->error->gt->engine = intel_engine_coredump_alloc(engine, gfp, CORE_DUMP_FLAG_NONE); if (!cap->error->gt->engine) goto err_gt; cap->error->gt->engine->hung = true; return cap; err_gt: kfree(cap->error->gt); err_gpu: kfree(cap->error); err_cap: kfree(cap); return NULL; } static struct i915_request * active_context(struct intel_engine_cs *engine, u32 ccid) { const struct intel_engine_execlists * const el = &engine->execlists; struct i915_request * const *port, *rq; /* * Use the most recent result from process_csb(), but just in case * we trigger an error (via interrupt) before the first CS event has * been written, peek at the next submission. */ for (port = el->active; (rq = *port); port++) { if (rq->context->lrc.ccid == ccid) { ENGINE_TRACE(engine, "ccid:%x found at active:%zd\n", ccid, port - el->active); return rq; } } for (port = el->pending; (rq = *port); port++) { if (rq->context->lrc.ccid == ccid) { ENGINE_TRACE(engine, "ccid:%x found at pending:%zd\n", ccid, port - el->pending); return rq; } } ENGINE_TRACE(engine, "ccid:%x not found\n", ccid); return NULL; } static u32 active_ccid(struct intel_engine_cs *engine) { return ENGINE_READ_FW(engine, RING_EXECLIST_STATUS_HI); } static void execlists_capture(struct intel_engine_cs *engine) { struct execlists_capture *cap; if (!IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)) return; /* * We need to _quickly_ capture the engine state before we reset. * We are inside an atomic section (softirq) here and we are delaying * the forced preemption event. */ cap = capture_regs(engine); if (!cap) return; spin_lock_irq(&engine->sched_engine->lock); cap->rq = active_context(engine, active_ccid(engine)); if (cap->rq) { cap->rq = active_request(cap->rq->context->timeline, cap->rq); cap->rq = i915_request_get_rcu(cap->rq); } spin_unlock_irq(&engine->sched_engine->lock); if (!cap->rq) goto err_free; /* * Remove the request from the execlists queue, and take ownership * of the request. We pass it to our worker who will _slowly_ compress * all the pages the _user_ requested for debugging their batch, after * which we return it to the queue for signaling. * * By removing them from the execlists queue, we also remove the * requests from being processed by __unwind_incomplete_requests() * during the intel_engine_reset(), and so they will *not* be replayed * afterwards. * * Note that because we have not yet reset the engine at this point, * it is possible for the request that we have identified as being * guilty, did in fact complete and we will then hit an arbitration * point allowing the outstanding preemption to succeed. The likelihood * of that is very low (as capturing of the engine registers should be * fast enough to run inside an irq-off atomic section!), so we will * simply hold that request accountable for being non-preemptible * long enough to force the reset. */ if (!execlists_hold(engine, cap->rq)) goto err_rq; INIT_WORK(&cap->work, execlists_capture_work); schedule_work(&cap->work); return; err_rq: i915_request_put(cap->rq); err_free: i915_gpu_coredump_put(cap->error); kfree(cap); } static void execlists_reset(struct intel_engine_cs *engine, const char *msg) { const unsigned int bit = I915_RESET_ENGINE + engine->id; unsigned long *lock = &engine->gt->reset.flags; if (!intel_has_reset_engine(engine->gt)) return; if (test_and_set_bit(bit, lock)) return; ENGINE_TRACE(engine, "reset for %s\n", msg); /* Mark this tasklet as disabled to avoid waiting for it to complete */ tasklet_disable_nosync(&engine->sched_engine->tasklet); ring_set_paused(engine, 1); /* Freeze the current request in place */ execlists_capture(engine); intel_engine_reset(engine, msg); tasklet_enable(&engine->sched_engine->tasklet); clear_and_wake_up_bit(bit, lock); } static bool preempt_timeout(const struct intel_engine_cs *const engine) { const struct timer_list *t = &engine->execlists.preempt; if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT) return false; if (!timer_expired(t)) return false; return engine->execlists.pending[0]; } /* * Check the unread Context Status Buffers and manage the submission of new * contexts to the ELSP accordingly. */ static void execlists_submission_tasklet(struct tasklet_struct *t) { struct i915_sched_engine *sched_engine = from_tasklet(sched_engine, t, tasklet); struct intel_engine_cs * const engine = sched_engine->private_data; struct i915_request *post[2 * EXECLIST_MAX_PORTS]; struct i915_request **inactive; rcu_read_lock(); inactive = process_csb(engine, post); GEM_BUG_ON(inactive - post > ARRAY_SIZE(post)); if (unlikely(preempt_timeout(engine))) { const struct i915_request *rq = *engine->execlists.active; /* * If after the preempt-timeout expired, we are still on the * same active request/context as before we initiated the * preemption, reset the engine. * * However, if we have processed a CS event to switch contexts, * but not yet processed the CS event for the pending * preemption, reset the timer allowing the new context to * gracefully exit. */ cancel_timer(&engine->execlists.preempt); if (rq == engine->execlists.preempt_target) engine->execlists.error_interrupt |= ERROR_PREEMPT; else set_timer_ms(&engine->execlists.preempt, active_preempt_timeout(engine, rq)); } if (unlikely(READ_ONCE(engine->execlists.error_interrupt))) { const char *msg; /* Generate the error message in priority wrt to the user! */ if (engine->execlists.error_interrupt & GENMASK(15, 0)) msg = "CS error"; /* thrown by a user payload */ else if (engine->execlists.error_interrupt & ERROR_CSB) msg = "invalid CSB event"; else if (engine->execlists.error_interrupt & ERROR_PREEMPT) msg = "preemption time out"; else msg = "internal error"; engine->execlists.error_interrupt = 0; execlists_reset(engine, msg); } if (!engine->execlists.pending[0]) { execlists_dequeue_irq(engine); start_timeslice(engine); } post_process_csb(post, inactive); rcu_read_unlock(); } static void execlists_irq_handler(struct intel_engine_cs *engine, u16 iir) { bool tasklet = false; if (unlikely(iir & GT_CS_MASTER_ERROR_INTERRUPT)) { u32 eir; /* Upper 16b are the enabling mask, rsvd for internal errors */ eir = ENGINE_READ(engine, RING_EIR) & GENMASK(15, 0); ENGINE_TRACE(engine, "CS error: %x\n", eir); /* Disable the error interrupt until after the reset */ if (likely(eir)) { ENGINE_WRITE(engine, RING_EMR, ~0u); ENGINE_WRITE(engine, RING_EIR, eir); WRITE_ONCE(engine->execlists.error_interrupt, eir); tasklet = true; } } if (iir & GT_WAIT_SEMAPHORE_INTERRUPT) { WRITE_ONCE(engine->execlists.yield, ENGINE_READ_FW(engine, RING_EXECLIST_STATUS_HI)); ENGINE_TRACE(engine, "semaphore yield: %08x\n", engine->execlists.yield); if (del_timer(&engine->execlists.timer)) tasklet = true; } if (iir & GT_CONTEXT_SWITCH_INTERRUPT) tasklet = true; if (iir & GT_RENDER_USER_INTERRUPT) intel_engine_signal_breadcrumbs(engine); if (tasklet) tasklet_hi_schedule(&engine->sched_engine->tasklet); } static void __execlists_kick(struct intel_engine_execlists *execlists) { struct intel_engine_cs *engine = container_of(execlists, typeof(*engine), execlists); /* Kick the tasklet for some interrupt coalescing and reset handling */ tasklet_hi_schedule(&engine->sched_engine->tasklet); } #define execlists_kick(t, member) \ __execlists_kick(container_of(t, struct intel_engine_execlists, member)) static void execlists_timeslice(struct timer_list *timer) { execlists_kick(timer, timer); } static void execlists_preempt(struct timer_list *timer) { execlists_kick(timer, preempt); } static void queue_request(struct intel_engine_cs *engine, struct i915_request *rq) { GEM_BUG_ON(!list_empty(&rq->sched.link)); list_add_tail(&rq->sched.link, i915_sched_lookup_priolist(engine->sched_engine, rq_prio(rq))); set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); } static bool submit_queue(struct intel_engine_cs *engine, const struct i915_request *rq) { struct i915_sched_engine *sched_engine = engine->sched_engine; if (rq_prio(rq) <= sched_engine->queue_priority_hint) return false; sched_engine->queue_priority_hint = rq_prio(rq); return true; } static bool ancestor_on_hold(const struct intel_engine_cs *engine, const struct i915_request *rq) { GEM_BUG_ON(i915_request_on_hold(rq)); return !list_empty(&engine->sched_engine->hold) && hold_request(rq); } static void execlists_submit_request(struct i915_request *request) { struct intel_engine_cs *engine = request->engine; unsigned long flags; /* Will be called from irq-context when using foreign fences. */ spin_lock_irqsave(&engine->sched_engine->lock, flags); if (unlikely(ancestor_on_hold(engine, request))) { RQ_TRACE(request, "ancestor on hold\n"); list_add_tail(&request->sched.link, &engine->sched_engine->hold); i915_request_set_hold(request); } else { queue_request(engine, request); GEM_BUG_ON(i915_sched_engine_is_empty(engine->sched_engine)); GEM_BUG_ON(list_empty(&request->sched.link)); if (submit_queue(engine, request)) __execlists_kick(&engine->execlists); } spin_unlock_irqrestore(&engine->sched_engine->lock, flags); } static int __execlists_context_pre_pin(struct intel_context *ce, struct intel_engine_cs *engine, struct i915_gem_ww_ctx *ww, void **vaddr) { int err; err = lrc_pre_pin(ce, engine, ww, vaddr); if (err) return err; if (!__test_and_set_bit(CONTEXT_INIT_BIT, &ce->flags)) { lrc_init_state(ce, engine, *vaddr); __i915_gem_object_flush_map(ce->state->obj, 0, engine->context_size); } return 0; } static int execlists_context_pre_pin(struct intel_context *ce, struct i915_gem_ww_ctx *ww, void **vaddr) { return __execlists_context_pre_pin(ce, ce->engine, ww, vaddr); } static int execlists_context_pin(struct intel_context *ce, void *vaddr) { return lrc_pin(ce, ce->engine, vaddr); } static int execlists_context_alloc(struct intel_context *ce) { return lrc_alloc(ce, ce->engine); } static void execlists_context_cancel_request(struct intel_context *ce, struct i915_request *rq) { struct intel_engine_cs *engine = NULL; i915_request_active_engine(rq, &engine); if (engine && intel_engine_pulse(engine)) intel_gt_handle_error(engine->gt, engine->mask, 0, "request cancellation by %s", current->comm); } static struct intel_context * execlists_create_parallel(struct intel_engine_cs **engines, unsigned int num_siblings, unsigned int width) { struct intel_context *parent = NULL, *ce, *err; int i; GEM_BUG_ON(num_siblings != 1); for (i = 0; i < width; ++i) { ce = intel_context_create(engines[i]); if (IS_ERR(ce)) { err = ce; goto unwind; } if (i == 0) parent = ce; else intel_context_bind_parent_child(parent, ce); } parent->parallel.fence_context = dma_fence_context_alloc(1); intel_context_set_nopreempt(parent); for_each_child(parent, ce) intel_context_set_nopreempt(ce); return parent; unwind: if (parent) intel_context_put(parent); return err; } static const struct intel_context_ops execlists_context_ops = { .flags = COPS_HAS_INFLIGHT | COPS_RUNTIME_CYCLES, .alloc = execlists_context_alloc, .cancel_request = execlists_context_cancel_request, .pre_pin = execlists_context_pre_pin, .pin = execlists_context_pin, .unpin = lrc_unpin, .post_unpin = lrc_post_unpin, .enter = intel_context_enter_engine, .exit = intel_context_exit_engine, .reset = lrc_reset, .destroy = lrc_destroy, .create_parallel = execlists_create_parallel, .create_virtual = execlists_create_virtual, }; static int emit_pdps(struct i915_request *rq) { const struct intel_engine_cs * const engine = rq->engine; struct i915_ppgtt * const ppgtt = i915_vm_to_ppgtt(rq->context->vm); int err, i; u32 *cs; GEM_BUG_ON(intel_vgpu_active(rq->engine->i915)); /* * Beware ye of the dragons, this sequence is magic! * * Small changes to this sequence can cause anything from * GPU hangs to forcewake errors and machine lockups! */ cs = intel_ring_begin(rq, 2); if (IS_ERR(cs)) return PTR_ERR(cs); *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; *cs++ = MI_NOOP; intel_ring_advance(rq, cs); /* Flush any residual operations from the context load */ err = engine->emit_flush(rq, EMIT_FLUSH); if (err) return err; /* Magic required to prevent forcewake errors! */ err = engine->emit_flush(rq, EMIT_INVALIDATE); if (err) return err; cs = intel_ring_begin(rq, 4 * GEN8_3LVL_PDPES + 2); if (IS_ERR(cs)) return PTR_ERR(cs); /* Ensure the LRI have landed before we invalidate & continue */ *cs++ = MI_LOAD_REGISTER_IMM(2 * GEN8_3LVL_PDPES) | MI_LRI_FORCE_POSTED; for (i = GEN8_3LVL_PDPES; i--; ) { const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i); u32 base = engine->mmio_base; *cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, i)); *cs++ = upper_32_bits(pd_daddr); *cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, i)); *cs++ = lower_32_bits(pd_daddr); } *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; intel_ring_advance(rq, cs); intel_ring_advance(rq, cs); return 0; } static int execlists_request_alloc(struct i915_request *request) { int ret; GEM_BUG_ON(!intel_context_is_pinned(request->context)); /* * Flush enough space to reduce the likelihood of waiting after * we start building the request - in which case we will just * have to repeat work. */ request->reserved_space += EXECLISTS_REQUEST_SIZE; /* * Note that after this point, we have committed to using * this request as it is being used to both track the * state of engine initialisation and liveness of the * golden renderstate above. Think twice before you try * to cancel/unwind this request now. */ if (!i915_vm_is_4lvl(request->context->vm)) { ret = emit_pdps(request); if (ret) return ret; } /* Unconditionally invalidate GPU caches and TLBs. */ ret = request->engine->emit_flush(request, EMIT_INVALIDATE); if (ret) return ret; request->reserved_space -= EXECLISTS_REQUEST_SIZE; return 0; } static void reset_csb_pointers(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; const unsigned int reset_value = execlists->csb_size - 1; ring_set_paused(engine, 0); /* * Sometimes Icelake forgets to reset its pointers on a GPU reset. * Bludgeon them with a mmio update to be sure. */ ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, 0xffff << 16 | reset_value << 8 | reset_value); ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); /* * After a reset, the HW starts writing into CSB entry [0]. We * therefore have to set our HEAD pointer back one entry so that * the *first* entry we check is entry 0. To complicate this further, * as we don't wait for the first interrupt after reset, we have to * fake the HW write to point back to the last entry so that our * inline comparison of our cached head position against the last HW * write works even before the first interrupt. */ execlists->csb_head = reset_value; WRITE_ONCE(*execlists->csb_write, reset_value); wmb(); /* Make sure this is visible to HW (paranoia?) */ /* Check that the GPU does indeed update the CSB entries! */ memset(execlists->csb_status, -1, (reset_value + 1) * sizeof(u64)); drm_clflush_virt_range(execlists->csb_status, execlists->csb_size * sizeof(execlists->csb_status)); /* Once more for luck and our trusty paranoia */ ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, 0xffff << 16 | reset_value << 8 | reset_value); ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); GEM_BUG_ON(READ_ONCE(*execlists->csb_write) != reset_value); } static void sanitize_hwsp(struct intel_engine_cs *engine) { struct intel_timeline *tl; list_for_each_entry(tl, &engine->status_page.timelines, engine_link) intel_timeline_reset_seqno(tl); } static void execlists_sanitize(struct intel_engine_cs *engine) { GEM_BUG_ON(execlists_active(&engine->execlists)); /* * Poison residual state on resume, in case the suspend didn't! * * We have to assume that across suspend/resume (or other loss * of control) that the contents of our pinned buffers has been * lost, replaced by garbage. Since this doesn't always happen, * let's poison such state so that we more quickly spot when * we falsely assume it has been preserved. */ if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) memset(engine->status_page.addr, POISON_INUSE, PAGE_SIZE); reset_csb_pointers(engine); /* * The kernel_context HWSP is stored in the status_page. As above, * that may be lost on resume/initialisation, and so we need to * reset the value in the HWSP. */ sanitize_hwsp(engine); /* And scrub the dirty cachelines for the HWSP */ drm_clflush_virt_range(engine->status_page.addr, PAGE_SIZE); intel_engine_reset_pinned_contexts(engine); } static void enable_error_interrupt(struct intel_engine_cs *engine) { u32 status; engine->execlists.error_interrupt = 0; ENGINE_WRITE(engine, RING_EMR, ~0u); ENGINE_WRITE(engine, RING_EIR, ~0u); /* clear all existing errors */ status = ENGINE_READ(engine, RING_ESR); if (unlikely(status)) { drm_err(&engine->i915->drm, "engine '%s' resumed still in error: %08x\n", engine->name, status); __intel_gt_reset(engine->gt, engine->mask); } /* * On current gen8+, we have 2 signals to play with * * - I915_ERROR_INSTUCTION (bit 0) * * Generate an error if the command parser encounters an invalid * instruction * * This is a fatal error. * * - CP_PRIV (bit 2) * * Generate an error on privilege violation (where the CP replaces * the instruction with a no-op). This also fires for writes into * read-only scratch pages. * * This is a non-fatal error, parsing continues. * * * there are a few others defined for odd HW that we do not use * * Since CP_PRIV fires for cases where we have chosen to ignore the * error (as the HW is validating and suppressing the mistakes), we * only unmask the instruction error bit. */ ENGINE_WRITE(engine, RING_EMR, ~I915_ERROR_INSTRUCTION); } static void enable_execlists(struct intel_engine_cs *engine) { u32 mode; assert_forcewakes_active(engine->uncore, FORCEWAKE_ALL); intel_engine_set_hwsp_writemask(engine, ~0u); /* HWSTAM */ if (GRAPHICS_VER(engine->i915) >= 11) mode = _MASKED_BIT_ENABLE(GEN11_GFX_DISABLE_LEGACY_MODE); else mode = _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE); ENGINE_WRITE_FW(engine, RING_MODE_GEN7, mode); ENGINE_WRITE_FW(engine, RING_MI_MODE, _MASKED_BIT_DISABLE(STOP_RING)); ENGINE_WRITE_FW(engine, RING_HWS_PGA, i915_ggtt_offset(engine->status_page.vma)); ENGINE_POSTING_READ(engine, RING_HWS_PGA); enable_error_interrupt(engine); } static int execlists_resume(struct intel_engine_cs *engine) { intel_mocs_init_engine(engine); intel_breadcrumbs_reset(engine->breadcrumbs); enable_execlists(engine); if (engine->flags & I915_ENGINE_FIRST_RENDER_COMPUTE) xehp_enable_ccs_engines(engine); return 0; } static void execlists_reset_prepare(struct intel_engine_cs *engine) { ENGINE_TRACE(engine, "depth<-%d\n", atomic_read(&engine->sched_engine->tasklet.count)); /* * Prevent request submission to the hardware until we have * completed the reset in i915_gem_reset_finish(). If a request * is completed by one engine, it may then queue a request * to a second via its execlists->tasklet *just* as we are * calling engine->resume() and also writing the ELSP. * Turning off the execlists->tasklet until the reset is over * prevents the race. */ __tasklet_disable_sync_once(&engine->sched_engine->tasklet); GEM_BUG_ON(!reset_in_progress(engine)); /* * We stop engines, otherwise we might get failed reset and a * dead gpu (on elk). Also as modern gpu as kbl can suffer * from system hang if batchbuffer is progressing when * the reset is issued, regardless of READY_TO_RESET ack. * Thus assume it is best to stop engines on all gens * where we have a gpu reset. * * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES) * * FIXME: Wa for more modern gens needs to be validated */ ring_set_paused(engine, 1); intel_engine_stop_cs(engine); /* * Wa_22011802037:gen11/gen12: In addition to stopping the cs, we need * to wait for any pending mi force wakeups */ if (IS_GRAPHICS_VER(engine->i915, 11, 12)) intel_engine_wait_for_pending_mi_fw(engine); engine->execlists.reset_ccid = active_ccid(engine); } static struct i915_request ** reset_csb(struct intel_engine_cs *engine, struct i915_request **inactive) { struct intel_engine_execlists * const execlists = &engine->execlists; drm_clflush_virt_range(execlists->csb_write, sizeof(execlists->csb_write[0])); inactive = process_csb(engine, inactive); /* drain preemption events */ /* Following the reset, we need to reload the CSB read/write pointers */ reset_csb_pointers(engine); return inactive; } static void execlists_reset_active(struct intel_engine_cs *engine, bool stalled) { struct intel_context *ce; struct i915_request *rq; u32 head; /* * Save the currently executing context, even if we completed * its request, it was still running at the time of the * reset and will have been clobbered. */ rq = active_context(engine, engine->execlists.reset_ccid); if (!rq) return; ce = rq->context; GEM_BUG_ON(!i915_vma_is_pinned(ce->state)); if (__i915_request_is_complete(rq)) { /* Idle context; tidy up the ring so we can restart afresh */ head = intel_ring_wrap(ce->ring, rq->tail); goto out_replay; } /* We still have requests in-flight; the engine should be active */ GEM_BUG_ON(!intel_engine_pm_is_awake(engine)); /* Context has requests still in-flight; it should not be idle! */ GEM_BUG_ON(i915_active_is_idle(&ce->active)); rq = active_request(ce->timeline, rq); head = intel_ring_wrap(ce->ring, rq->head); GEM_BUG_ON(head == ce->ring->tail); /* * If this request hasn't started yet, e.g. it is waiting on a * semaphore, we need to avoid skipping the request or else we * break the signaling chain. However, if the context is corrupt * the request will not restart and we will be stuck with a wedged * device. It is quite often the case that if we issue a reset * while the GPU is loading the context image, that the context * image becomes corrupt. * * Otherwise, if we have not started yet, the request should replay * perfectly and we do not need to flag the result as being erroneous. */ if (!__i915_request_has_started(rq)) goto out_replay; /* * If the request was innocent, we leave the request in the ELSP * and will try to replay it on restarting. The context image may * have been corrupted by the reset, in which case we may have * to service a new GPU hang, but more likely we can continue on * without impact. * * If the request was guilty, we presume the context is corrupt * and have to at least restore the RING register in the context * image back to the expected values to skip over the guilty request. */ __i915_request_reset(rq, stalled); /* * We want a simple context + ring to execute the breadcrumb update. * We cannot rely on the context being intact across the GPU hang, * so clear it and rebuild just what we need for the breadcrumb. * All pending requests for this context will be zapped, and any * future request will be after userspace has had the opportunity * to recreate its own state. */ out_replay: ENGINE_TRACE(engine, "replay {head:%04x, tail:%04x}\n", head, ce->ring->tail); lrc_reset_regs(ce, engine); ce->lrc.lrca = lrc_update_regs(ce, engine, head); } static void execlists_reset_csb(struct intel_engine_cs *engine, bool stalled) { struct intel_engine_execlists * const execlists = &engine->execlists; struct i915_request *post[2 * EXECLIST_MAX_PORTS]; struct i915_request **inactive; rcu_read_lock(); inactive = reset_csb(engine, post); execlists_reset_active(engine, true); inactive = cancel_port_requests(execlists, inactive); post_process_csb(post, inactive); rcu_read_unlock(); } static void execlists_reset_rewind(struct intel_engine_cs *engine, bool stalled) { unsigned long flags; ENGINE_TRACE(engine, "\n"); /* Process the csb, find the guilty context and throw away */ execlists_reset_csb(engine, stalled); /* Push back any incomplete requests for replay after the reset. */ rcu_read_lock(); spin_lock_irqsave(&engine->sched_engine->lock, flags); __unwind_incomplete_requests(engine); spin_unlock_irqrestore(&engine->sched_engine->lock, flags); rcu_read_unlock(); } static void nop_submission_tasklet(struct tasklet_struct *t) { struct i915_sched_engine *sched_engine = from_tasklet(sched_engine, t, tasklet); struct intel_engine_cs * const engine = sched_engine->private_data; /* The driver is wedged; don't process any more events. */ WRITE_ONCE(engine->sched_engine->queue_priority_hint, INT_MIN); } static void execlists_reset_cancel(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct i915_sched_engine * const sched_engine = engine->sched_engine; struct i915_request *rq, *rn; struct rb_node *rb; unsigned long flags; ENGINE_TRACE(engine, "\n"); /* * Before we call engine->cancel_requests(), we should have exclusive * access to the submission state. This is arranged for us by the * caller disabling the interrupt generation, the tasklet and other * threads that may then access the same state, giving us a free hand * to reset state. However, we still need to let lockdep be aware that * we know this state may be accessed in hardirq context, so we * disable the irq around this manipulation and we want to keep * the spinlock focused on its duties and not accidentally conflate * coverage to the submission's irq state. (Similarly, although we * shouldn't need to disable irq around the manipulation of the * submission's irq state, we also wish to remind ourselves that * it is irq state.) */ execlists_reset_csb(engine, true); rcu_read_lock(); spin_lock_irqsave(&engine->sched_engine->lock, flags); /* Mark all executing requests as skipped. */ list_for_each_entry(rq, &engine->sched_engine->requests, sched.link) i915_request_put(i915_request_mark_eio(rq)); intel_engine_signal_breadcrumbs(engine); /* Flush the queued requests to the timeline list (for retiring). */ while ((rb = rb_first_cached(&sched_engine->queue))) { struct i915_priolist *p = to_priolist(rb); priolist_for_each_request_consume(rq, rn, p) { if (i915_request_mark_eio(rq)) { __i915_request_submit(rq); i915_request_put(rq); } } rb_erase_cached(&p->node, &sched_engine->queue); i915_priolist_free(p); } /* On-hold requests will be flushed to timeline upon their release */ list_for_each_entry(rq, &sched_engine->hold, sched.link) i915_request_put(i915_request_mark_eio(rq)); /* Cancel all attached virtual engines */ while ((rb = rb_first_cached(&execlists->virtual))) { struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); spin_lock(&ve->base.sched_engine->lock); rq = fetch_and_zero(&ve->request); if (rq) { if (i915_request_mark_eio(rq)) { rq->engine = engine; __i915_request_submit(rq); i915_request_put(rq); } i915_request_put(rq); ve->base.sched_engine->queue_priority_hint = INT_MIN; } spin_unlock(&ve->base.sched_engine->lock); } /* Remaining _unready_ requests will be nop'ed when submitted */ sched_engine->queue_priority_hint = INT_MIN; sched_engine->queue = RB_ROOT_CACHED; GEM_BUG_ON(__tasklet_is_enabled(&engine->sched_engine->tasklet)); engine->sched_engine->tasklet.callback = nop_submission_tasklet; spin_unlock_irqrestore(&engine->sched_engine->lock, flags); rcu_read_unlock(); } static void execlists_reset_finish(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; /* * After a GPU reset, we may have requests to replay. Do so now while * we still have the forcewake to be sure that the GPU is not allowed * to sleep before we restart and reload a context. * * If the GPU reset fails, the engine may still be alive with requests * inflight. We expect those to complete, or for the device to be * reset as the next level of recovery, and as a final resort we * will declare the device wedged. */ GEM_BUG_ON(!reset_in_progress(engine)); /* And kick in case we missed a new request submission. */ if (__tasklet_enable(&engine->sched_engine->tasklet)) __execlists_kick(execlists); ENGINE_TRACE(engine, "depth->%d\n", atomic_read(&engine->sched_engine->tasklet.count)); } static void gen8_logical_ring_enable_irq(struct intel_engine_cs *engine) { ENGINE_WRITE(engine, RING_IMR, ~(engine->irq_enable_mask | engine->irq_keep_mask)); ENGINE_POSTING_READ(engine, RING_IMR); } static void gen8_logical_ring_disable_irq(struct intel_engine_cs *engine) { ENGINE_WRITE(engine, RING_IMR, ~engine->irq_keep_mask); } static void execlists_park(struct intel_engine_cs *engine) { cancel_timer(&engine->execlists.timer); cancel_timer(&engine->execlists.preempt); } static void add_to_engine(struct i915_request *rq) { lockdep_assert_held(&rq->engine->sched_engine->lock); list_move_tail(&rq->sched.link, &rq->engine->sched_engine->requests); } static void remove_from_engine(struct i915_request *rq) { struct intel_engine_cs *engine, *locked; /* * Virtual engines complicate acquiring the engine timeline lock, * as their rq->engine pointer is not stable until under that * engine lock. The simple ploy we use is to take the lock then * check that the rq still belongs to the newly locked engine. */ locked = READ_ONCE(rq->engine); spin_lock_irq(&locked->sched_engine->lock); while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) { spin_unlock(&locked->sched_engine->lock); spin_lock(&engine->sched_engine->lock); locked = engine; } list_del_init(&rq->sched.link); clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags); /* Prevent further __await_execution() registering a cb, then flush */ set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags); spin_unlock_irq(&locked->sched_engine->lock); i915_request_notify_execute_cb_imm(rq); } static bool can_preempt(struct intel_engine_cs *engine) { if (GRAPHICS_VER(engine->i915) > 8) return true; /* GPGPU on bdw requires extra w/a; not implemented */ return engine->class != RENDER_CLASS; } static void kick_execlists(const struct i915_request *rq, int prio) { struct intel_engine_cs *engine = rq->engine; struct i915_sched_engine *sched_engine = engine->sched_engine; const struct i915_request *inflight; /* * We only need to kick the tasklet once for the high priority * new context we add into the queue. */ if (prio <= sched_engine->queue_priority_hint) return; rcu_read_lock(); /* Nothing currently active? We're overdue for a submission! */ inflight = execlists_active(&engine->execlists); if (!inflight) goto unlock; /* * If we are already the currently executing context, don't * bother evaluating if we should preempt ourselves. */ if (inflight->context == rq->context) goto unlock; ENGINE_TRACE(engine, "bumping queue-priority-hint:%d for rq:%llx:%lld, inflight:%llx:%lld prio %d\n", prio, rq->fence.context, rq->fence.seqno, inflight->fence.context, inflight->fence.seqno, inflight->sched.attr.priority); sched_engine->queue_priority_hint = prio; /* * Allow preemption of low -> normal -> high, but we do * not allow low priority tasks to preempt other low priority * tasks under the impression that latency for low priority * tasks does not matter (as much as background throughput), * so kiss. */ if (prio >= max(I915_PRIORITY_NORMAL, rq_prio(inflight))) tasklet_hi_schedule(&sched_engine->tasklet); unlock: rcu_read_unlock(); } static void execlists_set_default_submission(struct intel_engine_cs *engine) { engine->submit_request = execlists_submit_request; engine->sched_engine->schedule = i915_schedule; engine->sched_engine->kick_backend = kick_execlists; engine->sched_engine->tasklet.callback = execlists_submission_tasklet; } static void execlists_shutdown(struct intel_engine_cs *engine) { /* Synchronise with residual timers and any softirq they raise */ del_timer_sync(&engine->execlists.timer); del_timer_sync(&engine->execlists.preempt); tasklet_kill(&engine->sched_engine->tasklet); } static void execlists_release(struct intel_engine_cs *engine) { engine->sanitize = NULL; /* no longer in control, nothing to sanitize */ execlists_shutdown(engine); intel_engine_cleanup_common(engine); lrc_fini_wa_ctx(engine); } static ktime_t __execlists_engine_busyness(struct intel_engine_cs *engine, ktime_t *now) { struct intel_engine_execlists_stats *stats = &engine->stats.execlists; ktime_t total = stats->total; /* * If the engine is executing something at the moment * add it to the total. */ *now = ktime_get(); if (READ_ONCE(stats->active)) total = ktime_add(total, ktime_sub(*now, stats->start)); return total; } static ktime_t execlists_engine_busyness(struct intel_engine_cs *engine, ktime_t *now) { struct intel_engine_execlists_stats *stats = &engine->stats.execlists; unsigned int seq; ktime_t total; do { seq = read_seqcount_begin(&stats->lock); total = __execlists_engine_busyness(engine, now); } while (read_seqcount_retry(&stats->lock, seq)); return total; } static void logical_ring_default_vfuncs(struct intel_engine_cs *engine) { /* Default vfuncs which can be overridden by each engine. */ engine->resume = execlists_resume; engine->cops = &execlists_context_ops; engine->request_alloc = execlists_request_alloc; engine->add_active_request = add_to_engine; engine->remove_active_request = remove_from_engine; engine->reset.prepare = execlists_reset_prepare; engine->reset.rewind = execlists_reset_rewind; engine->reset.cancel = execlists_reset_cancel; engine->reset.finish = execlists_reset_finish; engine->park = execlists_park; engine->unpark = NULL; engine->emit_flush = gen8_emit_flush_xcs; engine->emit_init_breadcrumb = gen8_emit_init_breadcrumb; engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb_xcs; if (GRAPHICS_VER(engine->i915) >= 12) { engine->emit_fini_breadcrumb = gen12_emit_fini_breadcrumb_xcs; engine->emit_flush = gen12_emit_flush_xcs; } engine->set_default_submission = execlists_set_default_submission; if (GRAPHICS_VER(engine->i915) < 11) { engine->irq_enable = gen8_logical_ring_enable_irq; engine->irq_disable = gen8_logical_ring_disable_irq; } else { /* * TODO: On Gen11 interrupt masks need to be clear * to allow C6 entry. Keep interrupts enabled at * and take the hit of generating extra interrupts * until a more refined solution exists. */ } intel_engine_set_irq_handler(engine, execlists_irq_handler); engine->flags |= I915_ENGINE_SUPPORTS_STATS; if (!intel_vgpu_active(engine->i915)) { engine->flags |= I915_ENGINE_HAS_SEMAPHORES; if (can_preempt(engine)) { engine->flags |= I915_ENGINE_HAS_PREEMPTION; if (CONFIG_DRM_I915_TIMESLICE_DURATION) engine->flags |= I915_ENGINE_HAS_TIMESLICES; } } if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50)) { if (intel_engine_has_preemption(engine)) engine->emit_bb_start = gen125_emit_bb_start; else engine->emit_bb_start = gen125_emit_bb_start_noarb; } else { if (intel_engine_has_preemption(engine)) engine->emit_bb_start = gen8_emit_bb_start; else engine->emit_bb_start = gen8_emit_bb_start_noarb; } engine->busyness = execlists_engine_busyness; } static void logical_ring_default_irqs(struct intel_engine_cs *engine) { unsigned int shift = 0; if (GRAPHICS_VER(engine->i915) < 11) { const u8 irq_shifts[] = { [RCS0] = GEN8_RCS_IRQ_SHIFT, [BCS0] = GEN8_BCS_IRQ_SHIFT, [VCS0] = GEN8_VCS0_IRQ_SHIFT, [VCS1] = GEN8_VCS1_IRQ_SHIFT, [VECS0] = GEN8_VECS_IRQ_SHIFT, }; shift = irq_shifts[engine->id]; } engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << shift; engine->irq_keep_mask = GT_CONTEXT_SWITCH_INTERRUPT << shift; engine->irq_keep_mask |= GT_CS_MASTER_ERROR_INTERRUPT << shift; engine->irq_keep_mask |= GT_WAIT_SEMAPHORE_INTERRUPT << shift; } static void rcs_submission_override(struct intel_engine_cs *engine) { switch (GRAPHICS_VER(engine->i915)) { case 12: engine->emit_flush = gen12_emit_flush_rcs; engine->emit_fini_breadcrumb = gen12_emit_fini_breadcrumb_rcs; break; case 11: engine->emit_flush = gen11_emit_flush_rcs; engine->emit_fini_breadcrumb = gen11_emit_fini_breadcrumb_rcs; break; default: engine->emit_flush = gen8_emit_flush_rcs; engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb_rcs; break; } } int intel_execlists_submission_setup(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct drm_i915_private *i915 = engine->i915; struct intel_uncore *uncore = engine->uncore; u32 base = engine->mmio_base; tasklet_setup(&engine->sched_engine->tasklet, execlists_submission_tasklet); timer_setup(&engine->execlists.timer, execlists_timeslice, 0); timer_setup(&engine->execlists.preempt, execlists_preempt, 0); logical_ring_default_vfuncs(engine); logical_ring_default_irqs(engine); if (engine->flags & I915_ENGINE_HAS_RCS_REG_STATE) rcs_submission_override(engine); lrc_init_wa_ctx(engine); if (HAS_LOGICAL_RING_ELSQ(i915)) { execlists->submit_reg = uncore->regs + i915_mmio_reg_offset(RING_EXECLIST_SQ_CONTENTS(base)); execlists->ctrl_reg = uncore->regs + i915_mmio_reg_offset(RING_EXECLIST_CONTROL(base)); engine->fw_domain = intel_uncore_forcewake_for_reg(engine->uncore, RING_EXECLIST_CONTROL(engine->mmio_base), FW_REG_WRITE); } else { execlists->submit_reg = uncore->regs + i915_mmio_reg_offset(RING_ELSP(base)); } execlists->csb_status = (u64 *)&engine->status_page.addr[I915_HWS_CSB_BUF0_INDEX]; execlists->csb_write = &engine->status_page.addr[INTEL_HWS_CSB_WRITE_INDEX(i915)]; if (GRAPHICS_VER(i915) < 11) execlists->csb_size = GEN8_CSB_ENTRIES; else execlists->csb_size = GEN11_CSB_ENTRIES; engine->context_tag = GENMASK(BITS_PER_LONG - 2, 0); if (GRAPHICS_VER(engine->i915) >= 11 && GRAPHICS_VER_FULL(engine->i915) < IP_VER(12, 50)) { execlists->ccid |= engine->instance << (GEN11_ENGINE_INSTANCE_SHIFT - 32); execlists->ccid |= engine->class << (GEN11_ENGINE_CLASS_SHIFT - 32); } /* Finally, take ownership and responsibility for cleanup! */ engine->sanitize = execlists_sanitize; engine->release = execlists_release; return 0; } static struct list_head *virtual_queue(struct virtual_engine *ve) { return &ve->base.sched_engine->default_priolist.requests; } static void rcu_virtual_context_destroy(struct work_struct *wrk) { struct virtual_engine *ve = container_of(wrk, typeof(*ve), rcu.work); unsigned int n; GEM_BUG_ON(ve->context.inflight); /* Preempt-to-busy may leave a stale request behind. */ if (unlikely(ve->request)) { struct i915_request *old; spin_lock_irq(&ve->base.sched_engine->lock); old = fetch_and_zero(&ve->request); if (old) { GEM_BUG_ON(!__i915_request_is_complete(old)); __i915_request_submit(old); i915_request_put(old); } spin_unlock_irq(&ve->base.sched_engine->lock); } /* * Flush the tasklet in case it is still running on another core. * * This needs to be done before we remove ourselves from the siblings' * rbtrees as in the case it is running in parallel, it may reinsert * the rb_node into a sibling. */ tasklet_kill(&ve->base.sched_engine->tasklet); /* Decouple ourselves from the siblings, no more access allowed. */ for (n = 0; n < ve->num_siblings; n++) { struct intel_engine_cs *sibling = ve->siblings[n]; struct rb_node *node = &ve->nodes[sibling->id].rb; if (RB_EMPTY_NODE(node)) continue; spin_lock_irq(&sibling->sched_engine->lock); /* Detachment is lazily performed in the sched_engine->tasklet */ if (!RB_EMPTY_NODE(node)) rb_erase_cached(node, &sibling->execlists.virtual); spin_unlock_irq(&sibling->sched_engine->lock); } GEM_BUG_ON(__tasklet_is_scheduled(&ve->base.sched_engine->tasklet)); GEM_BUG_ON(!list_empty(virtual_queue(ve))); lrc_fini(&ve->context); intel_context_fini(&ve->context); if (ve->base.breadcrumbs) intel_breadcrumbs_put(ve->base.breadcrumbs); if (ve->base.sched_engine) i915_sched_engine_put(ve->base.sched_engine); intel_engine_free_request_pool(&ve->base); kfree(ve); } static void virtual_context_destroy(struct kref *kref) { struct virtual_engine *ve = container_of(kref, typeof(*ve), context.ref); GEM_BUG_ON(!list_empty(&ve->context.signals)); /* * When destroying the virtual engine, we have to be aware that * it may still be in use from an hardirq/softirq context causing * the resubmission of a completed request (background completion * due to preempt-to-busy). Before we can free the engine, we need * to flush the submission code and tasklets that are still potentially * accessing the engine. Flushing the tasklets requires process context, * and since we can guard the resubmit onto the engine with an RCU read * lock, we can delegate the free of the engine to an RCU worker. */ INIT_RCU_WORK(&ve->rcu, rcu_virtual_context_destroy); queue_rcu_work(system_wq, &ve->rcu); } static void virtual_engine_initial_hint(struct virtual_engine *ve) { int swp; /* * Pick a random sibling on starting to help spread the load around. * * New contexts are typically created with exactly the same order * of siblings, and often started in batches. Due to the way we iterate * the array of sibling when submitting requests, sibling[0] is * prioritised for dequeuing. If we make sure that sibling[0] is fairly * randomised across the system, we also help spread the load by the * first engine we inspect being different each time. * * NB This does not force us to execute on this engine, it will just * typically be the first we inspect for submission. */ swp = prandom_u32_max(ve->num_siblings); if (swp) swap(ve->siblings[swp], ve->siblings[0]); } static int virtual_context_alloc(struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); return lrc_alloc(ce, ve->siblings[0]); } static int virtual_context_pre_pin(struct intel_context *ce, struct i915_gem_ww_ctx *ww, void **vaddr) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); /* Note: we must use a real engine class for setting up reg state */ return __execlists_context_pre_pin(ce, ve->siblings[0], ww, vaddr); } static int virtual_context_pin(struct intel_context *ce, void *vaddr) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); return lrc_pin(ce, ve->siblings[0], vaddr); } static void virtual_context_enter(struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); unsigned int n; for (n = 0; n < ve->num_siblings; n++) intel_engine_pm_get(ve->siblings[n]); intel_timeline_enter(ce->timeline); } static void virtual_context_exit(struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); unsigned int n; intel_timeline_exit(ce->timeline); for (n = 0; n < ve->num_siblings; n++) intel_engine_pm_put(ve->siblings[n]); } static struct intel_engine_cs * virtual_get_sibling(struct intel_engine_cs *engine, unsigned int sibling) { struct virtual_engine *ve = to_virtual_engine(engine); if (sibling >= ve->num_siblings) return NULL; return ve->siblings[sibling]; } static const struct intel_context_ops virtual_context_ops = { .flags = COPS_HAS_INFLIGHT | COPS_RUNTIME_CYCLES, .alloc = virtual_context_alloc, .cancel_request = execlists_context_cancel_request, .pre_pin = virtual_context_pre_pin, .pin = virtual_context_pin, .unpin = lrc_unpin, .post_unpin = lrc_post_unpin, .enter = virtual_context_enter, .exit = virtual_context_exit, .destroy = virtual_context_destroy, .get_sibling = virtual_get_sibling, }; static intel_engine_mask_t virtual_submission_mask(struct virtual_engine *ve) { struct i915_request *rq; intel_engine_mask_t mask; rq = READ_ONCE(ve->request); if (!rq) return 0; /* The rq is ready for submission; rq->execution_mask is now stable. */ mask = rq->execution_mask; if (unlikely(!mask)) { /* Invalid selection, submit to a random engine in error */ i915_request_set_error_once(rq, -ENODEV); mask = ve->siblings[0]->mask; } ENGINE_TRACE(&ve->base, "rq=%llx:%lld, mask=%x, prio=%d\n", rq->fence.context, rq->fence.seqno, mask, ve->base.sched_engine->queue_priority_hint); return mask; } static void virtual_submission_tasklet(struct tasklet_struct *t) { struct i915_sched_engine *sched_engine = from_tasklet(sched_engine, t, tasklet); struct virtual_engine * const ve = (struct virtual_engine *)sched_engine->private_data; const int prio = READ_ONCE(sched_engine->queue_priority_hint); intel_engine_mask_t mask; unsigned int n; rcu_read_lock(); mask = virtual_submission_mask(ve); rcu_read_unlock(); if (unlikely(!mask)) return; for (n = 0; n < ve->num_siblings; n++) { struct intel_engine_cs *sibling = READ_ONCE(ve->siblings[n]); struct ve_node * const node = &ve->nodes[sibling->id]; struct rb_node **parent, *rb; bool first; if (!READ_ONCE(ve->request)) break; /* already handled by a sibling's tasklet */ spin_lock_irq(&sibling->sched_engine->lock); if (unlikely(!(mask & sibling->mask))) { if (!RB_EMPTY_NODE(&node->rb)) { rb_erase_cached(&node->rb, &sibling->execlists.virtual); RB_CLEAR_NODE(&node->rb); } goto unlock_engine; } if (unlikely(!RB_EMPTY_NODE(&node->rb))) { /* * Cheat and avoid rebalancing the tree if we can * reuse this node in situ. */ first = rb_first_cached(&sibling->execlists.virtual) == &node->rb; if (prio == node->prio || (prio > node->prio && first)) goto submit_engine; rb_erase_cached(&node->rb, &sibling->execlists.virtual); } rb = NULL; first = true; parent = &sibling->execlists.virtual.rb_root.rb_node; while (*parent) { struct ve_node *other; rb = *parent; other = rb_entry(rb, typeof(*other), rb); if (prio > other->prio) { parent = &rb->rb_left; } else { parent = &rb->rb_right; first = false; } } rb_link_node(&node->rb, rb, parent); rb_insert_color_cached(&node->rb, &sibling->execlists.virtual, first); submit_engine: GEM_BUG_ON(RB_EMPTY_NODE(&node->rb)); node->prio = prio; if (first && prio > sibling->sched_engine->queue_priority_hint) tasklet_hi_schedule(&sibling->sched_engine->tasklet); unlock_engine: spin_unlock_irq(&sibling->sched_engine->lock); if (intel_context_inflight(&ve->context)) break; } } static void virtual_submit_request(struct i915_request *rq) { struct virtual_engine *ve = to_virtual_engine(rq->engine); unsigned long flags; ENGINE_TRACE(&ve->base, "rq=%llx:%lld\n", rq->fence.context, rq->fence.seqno); GEM_BUG_ON(ve->base.submit_request != virtual_submit_request); spin_lock_irqsave(&ve->base.sched_engine->lock, flags); /* By the time we resubmit a request, it may be completed */ if (__i915_request_is_complete(rq)) { __i915_request_submit(rq); goto unlock; } if (ve->request) { /* background completion from preempt-to-busy */ GEM_BUG_ON(!__i915_request_is_complete(ve->request)); __i915_request_submit(ve->request); i915_request_put(ve->request); } ve->base.sched_engine->queue_priority_hint = rq_prio(rq); ve->request = i915_request_get(rq); GEM_BUG_ON(!list_empty(virtual_queue(ve))); list_move_tail(&rq->sched.link, virtual_queue(ve)); tasklet_hi_schedule(&ve->base.sched_engine->tasklet); unlock: spin_unlock_irqrestore(&ve->base.sched_engine->lock, flags); } static struct intel_context * execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count, unsigned long flags) { struct virtual_engine *ve; unsigned int n; int err; ve = kzalloc(struct_size(ve, siblings, count), GFP_KERNEL); if (!ve) return ERR_PTR(-ENOMEM); ve->base.i915 = siblings[0]->i915; ve->base.gt = siblings[0]->gt; ve->base.uncore = siblings[0]->uncore; ve->base.id = -1; ve->base.class = OTHER_CLASS; ve->base.uabi_class = I915_ENGINE_CLASS_INVALID; ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL; ve->base.uabi_instance = I915_ENGINE_CLASS_INVALID_VIRTUAL; /* * The decision on whether to submit a request using semaphores * depends on the saturated state of the engine. We only compute * this during HW submission of the request, and we need for this * state to be globally applied to all requests being submitted * to this engine. Virtual engines encompass more than one physical * engine and so we cannot accurately tell in advance if one of those * engines is already saturated and so cannot afford to use a semaphore * and be pessimized in priority for doing so -- if we are the only * context using semaphores after all other clients have stopped, we * will be starved on the saturated system. Such a global switch for * semaphores is less than ideal, but alas is the current compromise. */ ve->base.saturated = ALL_ENGINES; snprintf(ve->base.name, sizeof(ve->base.name), "virtual"); intel_engine_init_execlists(&ve->base); ve->base.sched_engine = i915_sched_engine_create(ENGINE_VIRTUAL); if (!ve->base.sched_engine) { err = -ENOMEM; goto err_put; } ve->base.sched_engine->private_data = &ve->base; ve->base.cops = &virtual_context_ops; ve->base.request_alloc = execlists_request_alloc; ve->base.sched_engine->schedule = i915_schedule; ve->base.sched_engine->kick_backend = kick_execlists; ve->base.submit_request = virtual_submit_request; INIT_LIST_HEAD(virtual_queue(ve)); tasklet_setup(&ve->base.sched_engine->tasklet, virtual_submission_tasklet); intel_context_init(&ve->context, &ve->base); ve->base.breadcrumbs = intel_breadcrumbs_create(NULL); if (!ve->base.breadcrumbs) { err = -ENOMEM; goto err_put; } for (n = 0; n < count; n++) { struct intel_engine_cs *sibling = siblings[n]; GEM_BUG_ON(!is_power_of_2(sibling->mask)); if (sibling->mask & ve->base.mask) { DRM_DEBUG("duplicate %s entry in load balancer\n", sibling->name); err = -EINVAL; goto err_put; } /* * The virtual engine implementation is tightly coupled to * the execlists backend -- we push out request directly * into a tree inside each physical engine. We could support * layering if we handle cloning of the requests and * submitting a copy into each backend. */ if (sibling->sched_engine->tasklet.callback != execlists_submission_tasklet) { err = -ENODEV; goto err_put; } GEM_BUG_ON(RB_EMPTY_NODE(&ve->nodes[sibling->id].rb)); RB_CLEAR_NODE(&ve->nodes[sibling->id].rb); ve->siblings[ve->num_siblings++] = sibling; ve->base.mask |= sibling->mask; ve->base.logical_mask |= sibling->logical_mask; /* * All physical engines must be compatible for their emission * functions (as we build the instructions during request * construction and do not alter them before submission * on the physical engine). We use the engine class as a guide * here, although that could be refined. */ if (ve->base.class != OTHER_CLASS) { if (ve->base.class != sibling->class) { DRM_DEBUG("invalid mixing of engine class, sibling %d, already %d\n", sibling->class, ve->base.class); err = -EINVAL; goto err_put; } continue; } ve->base.class = sibling->class; ve->base.uabi_class = sibling->uabi_class; snprintf(ve->base.name, sizeof(ve->base.name), "v%dx%d", ve->base.class, count); ve->base.context_size = sibling->context_size; ve->base.add_active_request = sibling->add_active_request; ve->base.remove_active_request = sibling->remove_active_request; ve->base.emit_bb_start = sibling->emit_bb_start; ve->base.emit_flush = sibling->emit_flush; ve->base.emit_init_breadcrumb = sibling->emit_init_breadcrumb; ve->base.emit_fini_breadcrumb = sibling->emit_fini_breadcrumb; ve->base.emit_fini_breadcrumb_dw = sibling->emit_fini_breadcrumb_dw; ve->base.flags = sibling->flags; } ve->base.flags |= I915_ENGINE_IS_VIRTUAL; virtual_engine_initial_hint(ve); return &ve->context; err_put: intel_context_put(&ve->context); return ERR_PTR(err); } void intel_execlists_show_requests(struct intel_engine_cs *engine, struct drm_printer *m, void (*show_request)(struct drm_printer *m, const struct i915_request *rq, const char *prefix, int indent), unsigned int max) { const struct intel_engine_execlists *execlists = &engine->execlists; struct i915_sched_engine *sched_engine = engine->sched_engine; struct i915_request *rq, *last; unsigned long flags; unsigned int count; struct rb_node *rb; spin_lock_irqsave(&sched_engine->lock, flags); last = NULL; count = 0; list_for_each_entry(rq, &sched_engine->requests, sched.link) { if (count++ < max - 1) show_request(m, rq, "\t\t", 0); else last = rq; } if (last) { if (count > max) { drm_printf(m, "\t\t...skipping %d executing requests...\n", count - max); } show_request(m, last, "\t\t", 0); } if (sched_engine->queue_priority_hint != INT_MIN) drm_printf(m, "\t\tQueue priority hint: %d\n", READ_ONCE(sched_engine->queue_priority_hint)); last = NULL; count = 0; for (rb = rb_first_cached(&sched_engine->queue); rb; rb = rb_next(rb)) { struct i915_priolist *p = rb_entry(rb, typeof(*p), node); priolist_for_each_request(rq, p) { if (count++ < max - 1) show_request(m, rq, "\t\t", 0); else last = rq; } } if (last) { if (count > max) { drm_printf(m, "\t\t...skipping %d queued requests...\n", count - max); } show_request(m, last, "\t\t", 0); } last = NULL; count = 0; for (rb = rb_first_cached(&execlists->virtual); rb; rb = rb_next(rb)) { struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); struct i915_request *rq = READ_ONCE(ve->request); if (rq) { if (count++ < max - 1) show_request(m, rq, "\t\t", 0); else last = rq; } } if (last) { if (count > max) { drm_printf(m, "\t\t...skipping %d virtual requests...\n", count - max); } show_request(m, last, "\t\t", 0); } spin_unlock_irqrestore(&sched_engine->lock, flags); } #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) #include "selftest_execlists.c" #endif
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