/* * Copyright © 2014 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. * * Authors: * Ben Widawsky * Michel Thierry * Thomas Daniel * Oscar Mateo * */ /** * 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 #include "gem/i915_gem_context.h" #include "i915_drv.h" #include "i915_vgpu.h" #include "intel_engine_pm.h" #include "intel_gt.h" #include "intel_lrc_reg.h" #include "intel_mocs.h" #include "intel_renderstate.h" #include "intel_reset.h" #include "intel_workarounds.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 CTX_DESC_FORCE_RESTORE BIT_ULL(2) /* Typical size of the average request (2 pipecontrols and a MI_BB) */ #define EXECLISTS_REQUEST_SIZE 64 /* bytes */ #define WA_TAIL_DWORDS 2 #define WA_TAIL_BYTES (sizeof(u32) * WA_TAIL_DWORDS) struct virtual_engine { struct intel_engine_cs base; struct intel_context context; /* * 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]; /* * Keep track of bonded pairs -- restrictions upon on our selection * of physical engines any particular request may be submitted to. * If we receive a submit-fence from a master engine, we will only * use one of sibling_mask physical engines. */ struct ve_bond { const struct intel_engine_cs *master; intel_engine_mask_t sibling_mask; } *bonds; unsigned int num_bonds; /* And finally, which physical engines this virtual engine maps onto. */ unsigned int num_siblings; struct intel_engine_cs *siblings[0]; }; 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 int execlists_context_deferred_alloc(struct intel_context *ce, struct intel_engine_cs *engine); static void execlists_init_reg_state(u32 *reg_state, struct intel_context *ce, struct intel_engine_cs *engine, struct intel_ring *ring); static inline u32 intel_hws_preempt_address(struct intel_engine_cs *engine) { return (i915_ggtt_offset(engine->status_page.vma) + I915_GEM_HWS_PREEMPT_ADDR); } static inline 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 inline struct i915_priolist *to_priolist(struct rb_node *rb) { return rb_entry(rb, struct i915_priolist, node); } static inline int rq_prio(const struct i915_request *rq) { return 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; /* * On unwinding the active request, we give it a priority bump * if it has completed waiting on any semaphore. If we know that * the request has already started, we can prevent an unwanted * preempt-to-idle cycle by taking that into account now. */ if (__i915_request_has_started(rq)) prio |= I915_PRIORITY_NOSEMAPHORE; /* Restrict mere WAIT boosts from triggering preemption */ BUILD_BUG_ON(__NO_PREEMPTION & ~I915_PRIORITY_MASK); /* only internal */ return prio | __NO_PREEMPTION; } static int queue_prio(const struct intel_engine_execlists *execlists) { struct i915_priolist *p; struct rb_node *rb; rb = rb_first_cached(&execlists->queue); if (!rb) return INT_MIN; /* * As the priolist[] are inverted, with the highest priority in [0], * we have to flip the index value to become priority. */ p = to_priolist(rb); return ((p->priority + 1) << I915_USER_PRIORITY_SHIFT) - ffs(p->used); } static inline bool need_preempt(const struct intel_engine_cs *engine, const struct i915_request *rq, struct rb_node *rb) { int last_prio; /* * 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. */ last_prio = effective_prio(rq); if (!i915_scheduler_need_preempt(engine->execlists.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->active.requests) && rq_prio(list_next_entry(rq, sched.link)) > last_prio) return true; if (rb) { struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); bool preempt = false; if (engine == ve->siblings[0]) { /* only preempt one sibling */ struct i915_request *next; rcu_read_lock(); next = READ_ONCE(ve->request); if (next) preempt = rq_prio(next) > last_prio; rcu_read_unlock(); } if (preempt) return preempt; } /* * 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 queue_prio(&engine->execlists) > last_prio; } __maybe_unused static inline 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); } /* * The context descriptor encodes various attributes of a context, * including its GTT address and some flags. Because it's fairly * expensive to calculate, we'll just do it once and cache the result, * which remains valid until the context is unpinned. * * This is what a descriptor looks like, from LSB to MSB:: * * bits 0-11: flags, GEN8_CTX_* (cached in ctx->desc_template) * bits 12-31: LRCA, GTT address of (the HWSP of) this context * bits 32-52: ctx ID, a globally unique tag (highest bit used by GuC) * bits 53-54: mbz, reserved for use by hardware * bits 55-63: group ID, currently unused and set to 0 * * Starting from Gen11, the upper dword of the descriptor has a new format: * * bits 32-36: reserved * bits 37-47: SW context ID * bits 48:53: engine instance * bit 54: mbz, reserved for use by hardware * bits 55-60: SW counter * bits 61-63: engine class * * engine info, SW context ID and SW counter need to form a unique number * (Context ID) per lrc. */ static u64 lrc_descriptor(struct intel_context *ce, struct intel_engine_cs *engine) { struct i915_gem_context *ctx = ce->gem_context; u64 desc; BUILD_BUG_ON(MAX_CONTEXT_HW_ID > (BIT(GEN8_CTX_ID_WIDTH))); BUILD_BUG_ON(GEN11_MAX_CONTEXT_HW_ID > (BIT(GEN11_SW_CTX_ID_WIDTH))); desc = ctx->desc_template; /* bits 0-11 */ GEM_BUG_ON(desc & GENMASK_ULL(63, 12)); desc |= i915_ggtt_offset(ce->state) + LRC_HEADER_PAGES * PAGE_SIZE; /* bits 12-31 */ GEM_BUG_ON(desc & GENMASK_ULL(63, 32)); /* * The following 32bits are copied into the OA reports (dword 2). * Consider updating oa_get_render_ctx_id in i915_perf.c when changing * anything below. */ if (INTEL_GEN(engine->i915) >= 11) { GEM_BUG_ON(ctx->hw_id >= BIT(GEN11_SW_CTX_ID_WIDTH)); desc |= (u64)ctx->hw_id << GEN11_SW_CTX_ID_SHIFT; /* bits 37-47 */ desc |= (u64)engine->instance << GEN11_ENGINE_INSTANCE_SHIFT; /* bits 48-53 */ /* TODO: decide what to do with SW counter (bits 55-60) */ desc |= (u64)engine->class << GEN11_ENGINE_CLASS_SHIFT; /* bits 61-63 */ } else { GEM_BUG_ON(ctx->hw_id >= BIT(GEN8_CTX_ID_WIDTH)); desc |= (u64)ctx->hw_id << GEN8_CTX_ID_SHIFT; /* bits 32-52 */ } return desc; } static void unwind_wa_tail(struct i915_request *rq) { rq->tail = intel_ring_wrap(rq->ring, rq->wa_tail - WA_TAIL_BYTES); assert_ring_tail_valid(rq->ring, rq->tail); } static struct i915_request * __unwind_incomplete_requests(struct intel_engine_cs *engine) { struct i915_request *rq, *rn, *active = NULL; struct list_head *uninitialized_var(pl); int prio = I915_PRIORITY_INVALID; lockdep_assert_held(&engine->active.lock); list_for_each_entry_safe_reverse(rq, rn, &engine->active.requests, sched.link) { struct intel_engine_cs *owner; if (i915_request_completed(rq)) continue; /* XXX */ __i915_request_unsubmit(rq); unwind_wa_tail(rq); /* * Push the request back into the queue for later resubmission. * If this request is not native to this physical engine (i.e. * it came from a virtual source), push it back onto the virtual * engine so that it can be moved across onto another physical * engine as load dictates. */ owner = rq->hw_context->engine; if (likely(owner == engine)) { GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID); if (rq_prio(rq) != prio) { prio = rq_prio(rq); pl = i915_sched_lookup_priolist(engine, prio); } GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root)); list_move(&rq->sched.link, pl); active = rq; } else { rq->engine = owner; owner->submit_request(rq); active = NULL; } } 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 inline 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 inline struct i915_request * execlists_schedule_in(struct i915_request *rq, int idx) { struct intel_context *ce = rq->hw_context; int count; trace_i915_request_in(rq, idx); count = intel_context_inflight_count(ce); if (!count) { intel_context_get(ce); ce->inflight = rq->engine; execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); intel_engine_context_in(ce->inflight); } intel_context_inflight_inc(ce); GEM_BUG_ON(intel_context_inflight(ce) != rq->engine); return i915_request_get(rq); } static void kick_siblings(struct i915_request *rq, struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); struct i915_request *next = READ_ONCE(ve->request); if (next && next->execution_mask & ~rq->execution_mask) tasklet_schedule(&ve->base.execlists.tasklet); } static inline void execlists_schedule_out(struct i915_request *rq) { struct intel_context *ce = rq->hw_context; GEM_BUG_ON(!intel_context_inflight_count(ce)); trace_i915_request_out(rq); intel_context_inflight_dec(ce); if (!intel_context_inflight_count(ce)) { intel_engine_context_out(ce->inflight); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT); /* * 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. */ ce->inflight = NULL; if (rq->engine != ce->engine) kick_siblings(rq, ce); intel_context_put(ce); } i915_request_put(rq); } static u64 execlists_update_context(const struct i915_request *rq) { struct intel_context *ce = rq->hw_context; u64 desc; ce->lrc_reg_state[CTX_RING_TAIL + 1] = intel_ring_set_tail(rq->ring, rq->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. * * Furthermore, Braswell, at least, wants a full mb to be sure that * the writes are coherent in memory (visible to the GPU) prior to * execution, and not just visible to other CPUs (as is the result of * wmb). */ mb(); desc = ce->lrc_desc; ce->lrc_desc &= ~CTX_DESC_FORCE_RESTORE; return desc; } static inline 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 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); GEM_TRACE("%s: %s { %llx:%lld%s, %llx:%lld }\n", engine->name, msg, ports[0]->fence.context, ports[0]->fence.seqno, i915_request_completed(ports[0]) ? "!" : i915_request_started(ports[0]) ? "*" : "", ports[1] ? ports[1]->fence.context : 0, ports[1] ? ports[1]->fence.seqno : 0); } static __maybe_unused bool assert_pending_valid(const struct intel_engine_execlists *execlists, const char *msg) { struct i915_request * const *port, *rq; struct intel_context *ce = NULL; trace_ports(execlists, msg, execlists->pending); if (execlists->pending[execlists_num_ports(execlists)]) return false; for (port = execlists->pending; (rq = *port); port++) { if (ce == rq->hw_context) return false; ce = rq->hw_context; if (i915_request_completed(rq)) continue; if (i915_active_is_idle(&ce->active)) return false; if (!i915_vma_is_pinned(ce->state)) 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) && i915_gem_context_force_single_submission(ce->gem_context)); } 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 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)); if (!can_merge_ctx(prev->hw_context, next->hw_context)) return false; return true; } static void virtual_update_register_offsets(u32 *regs, struct intel_engine_cs *engine) { u32 base = engine->mmio_base; /* Must match execlists_init_reg_state()! */ regs[CTX_CONTEXT_CONTROL] = i915_mmio_reg_offset(RING_CONTEXT_CONTROL(base)); regs[CTX_RING_HEAD] = i915_mmio_reg_offset(RING_HEAD(base)); regs[CTX_RING_TAIL] = i915_mmio_reg_offset(RING_TAIL(base)); regs[CTX_RING_BUFFER_START] = i915_mmio_reg_offset(RING_START(base)); regs[CTX_RING_BUFFER_CONTROL] = i915_mmio_reg_offset(RING_CTL(base)); regs[CTX_BB_HEAD_U] = i915_mmio_reg_offset(RING_BBADDR_UDW(base)); regs[CTX_BB_HEAD_L] = i915_mmio_reg_offset(RING_BBADDR(base)); regs[CTX_BB_STATE] = i915_mmio_reg_offset(RING_BBSTATE(base)); regs[CTX_SECOND_BB_HEAD_U] = i915_mmio_reg_offset(RING_SBBADDR_UDW(base)); regs[CTX_SECOND_BB_HEAD_L] = i915_mmio_reg_offset(RING_SBBADDR(base)); regs[CTX_SECOND_BB_STATE] = i915_mmio_reg_offset(RING_SBBSTATE(base)); regs[CTX_CTX_TIMESTAMP] = i915_mmio_reg_offset(RING_CTX_TIMESTAMP(base)); regs[CTX_PDP3_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 3)); regs[CTX_PDP3_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 3)); regs[CTX_PDP2_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 2)); regs[CTX_PDP2_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 2)); regs[CTX_PDP1_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 1)); regs[CTX_PDP1_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 1)); regs[CTX_PDP0_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 0)); regs[CTX_PDP0_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 0)); if (engine->class == RENDER_CLASS) { regs[CTX_RCS_INDIRECT_CTX] = i915_mmio_reg_offset(RING_INDIRECT_CTX(base)); regs[CTX_RCS_INDIRECT_CTX_OFFSET] = i915_mmio_reg_offset(RING_INDIRECT_CTX_OFFSET(base)); regs[CTX_BB_PER_CTX_PTR] = i915_mmio_reg_offset(RING_BB_PER_CTX_PTR(base)); regs[CTX_R_PWR_CLK_STATE] = i915_mmio_reg_offset(GEN8_R_PWR_CLK_STATE); } } 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->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 void virtual_xfer_breadcrumbs(struct virtual_engine *ve, struct intel_engine_cs *engine) { struct intel_engine_cs *old = ve->siblings[0]; /* All unattached (rq->engine == old) must already be completed */ spin_lock(&old->breadcrumbs.irq_lock); if (!list_empty(&ve->context.signal_link)) { list_move_tail(&ve->context.signal_link, &engine->breadcrumbs.signalers); intel_engine_queue_breadcrumbs(engine); } spin_unlock(&old->breadcrumbs.irq_lock); } static struct i915_request * last_active(const struct intel_engine_execlists *execlists) { struct i915_request * const *last = execlists->active; while (*last && i915_request_completed(*last)) last++; return *last; } 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); list_for_each_entry(p, &rq->sched.waiters_list, wait_link) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); /* 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_started(w) && !i915_request_completed(rq)); GEM_BUG_ON(i915_request_is_active(w)); if (list_empty(&w->sched.link)) continue; /* Not yet submitted; unready */ if (rq_prio(w) < rq_prio(rq)) continue; GEM_BUG_ON(rq_prio(w) > rq_prio(rq)); 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, rq_prio(rq))); } static bool need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq) { int hint; if (list_is_last(&rq->sched.link, &engine->active.requests)) return false; hint = max(rq_prio(list_next_entry(rq, sched.link)), engine->execlists.queue_priority_hint); return hint >= effective_prio(rq); } static bool enable_timeslice(struct intel_engine_cs *engine) { struct i915_request *last = last_active(&engine->execlists); return last && need_timeslice(engine, last); } static void execlists_dequeue(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct i915_request **port = execlists->pending; struct i915_request ** const last_port = port + execlists->port_mask; struct i915_request *last; 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. */ for (rb = rb_first_cached(&execlists->virtual); rb; ) { struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); struct i915_request *rq = READ_ONCE(ve->request); if (!rq) { /* lazily cleanup after another engine handled rq */ rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); rb = rb_first_cached(&execlists->virtual); continue; } if (!virtual_matches(ve, rq, engine)) { rb = rb_next(rb); continue; } break; } /* * 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. */ last = last_active(execlists); if (last) { if (need_preempt(engine, last, rb)) { GEM_TRACE("%s: preempting last=%llx:%lld, prio=%d, hint=%d\n", engine->name, last->fence.context, last->fence.seqno, last->sched.attr.priority, execlists->queue_priority_hint); /* * 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); /* * If we need to return to the 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. */ last->hw_context->lrc_desc |= CTX_DESC_FORCE_RESTORE; last = NULL; } else if (need_timeslice(engine, last) && !timer_pending(&engine->execlists.timer)) { GEM_TRACE("%s: expired last=%llx:%lld, prio=%d, hint=%d\n", engine->name, last->fence.context, last->fence.seqno, last->sched.attr.priority, execlists->queue_priority_hint); 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 (!list_is_last(&last->sched.link, &engine->active.requests)) return; /* * WaIdleLiteRestore:bdw,skl * Apply the wa NOOPs to prevent * ring:HEAD == rq:TAIL as we resubmit the * request. See gen8_emit_fini_breadcrumb() for * where we prepare the padding after the * end of the request. */ last->tail = last->wa_tail; } } while (rb) { /* XXX virtual is always taking precedence */ struct virtual_engine *ve = rb_entry(rb, typeof(*ve), nodes[engine->id].rb); struct i915_request *rq; spin_lock(&ve->base.active.lock); rq = ve->request; if (unlikely(!rq)) { /* lost the race to a sibling */ spin_unlock(&ve->base.active.lock); rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); rb = rb_first_cached(&execlists->virtual); continue; } GEM_BUG_ON(rq != ve->request); GEM_BUG_ON(rq->engine != &ve->base); GEM_BUG_ON(rq->hw_context != &ve->context); if (rq_prio(rq) >= queue_prio(execlists)) { if (!virtual_matches(ve, rq, engine)) { spin_unlock(&ve->base.active.lock); rb = rb_next(rb); continue; } if (i915_request_completed(rq)) { ve->request = NULL; ve->base.execlists.queue_priority_hint = INT_MIN; rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); rq->engine = engine; __i915_request_submit(rq); spin_unlock(&ve->base.active.lock); rb = rb_first_cached(&execlists->virtual); continue; } if (last && !can_merge_rq(last, rq)) { spin_unlock(&ve->base.active.lock); return; /* leave this for another */ } GEM_TRACE("%s: virtual rq=%llx:%lld%s, new engine? %s\n", engine->name, rq->fence.context, rq->fence.seqno, i915_request_completed(rq) ? "!" : i915_request_started(rq) ? "*" : "", yesno(engine != ve->siblings[0])); ve->request = NULL; ve->base.execlists.queue_priority_hint = INT_MIN; rb_erase_cached(rb, &execlists->virtual); RB_CLEAR_NODE(rb); GEM_BUG_ON(!(rq->execution_mask & engine->mask)); rq->engine = engine; if (engine != ve->siblings[0]) { u32 *regs = ve->context.lrc_reg_state; unsigned int n; GEM_BUG_ON(READ_ONCE(ve->context.inflight)); virtual_update_register_offsets(regs, engine); if (!list_empty(&ve->context.signals)) virtual_xfer_breadcrumbs(ve, 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; } } GEM_BUG_ON(ve->siblings[0] != engine); } __i915_request_submit(rq); if (!i915_request_completed(rq)) { submit = true; last = rq; } } spin_unlock(&ve->base.active.lock); break; } while ((rb = rb_first_cached(&execlists->queue))) { struct i915_priolist *p = to_priolist(rb); struct i915_request *rq, *rn; int i; priolist_for_each_request_consume(rq, rn, p, i) { if (i915_request_completed(rq)) goto skip; /* * 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->hw_context == rq->hw_context) 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->hw_context) || ctx_single_port_submission(rq->hw_context)) goto done; *port = execlists_schedule_in(last, port - execlists->pending); port++; } last = rq; submit = true; skip: __i915_request_submit(rq); } rb_erase_cached(&p->node, &execlists->queue); i915_priolist_free(p); } done: /* * 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). */ execlists->queue_priority_hint = queue_prio(execlists); GEM_TRACE("%s: queue_priority_hint:%d, submit:%s\n", engine->name, execlists->queue_priority_hint, yesno(submit)); if (submit) { *port = execlists_schedule_in(last, port - execlists->pending); memset(port + 1, 0, (last_port - port) * sizeof(*port)); execlists_submit_ports(engine); } else { ring_set_paused(engine, 0); } } void execlists_cancel_port_requests(struct intel_engine_execlists * const execlists) { struct i915_request * const *port, *rq; for (port = execlists->pending; (rq = *port); port++) execlists_schedule_out(rq); memset(execlists->pending, 0, sizeof(execlists->pending)); for (port = execlists->active; (rq = *port); port++) execlists_schedule_out(rq); execlists->active = memset(execlists->inflight, 0, sizeof(execlists->inflight)); } static inline void invalidate_csb_entries(const u32 *first, const u32 *last) { clflush((void *)first); clflush((void *)last); } static inline bool reset_in_progress(const struct intel_engine_execlists *execlists) { return unlikely(!__tasklet_is_enabled(&execlists->tasklet)); } enum csb_step { CSB_NOP, CSB_PROMOTE, CSB_PREEMPT, CSB_COMPLETE, }; static inline enum csb_step csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb) { unsigned int status = *csb; if (status & GEN8_CTX_STATUS_IDLE_ACTIVE) return CSB_PROMOTE; if (status & GEN8_CTX_STATUS_PREEMPTED) return CSB_PREEMPT; if (*execlists->active) return CSB_COMPLETE; return CSB_NOP; } static void process_csb(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; const u32 * const buf = execlists->csb_status; const u8 num_entries = execlists->csb_size; u8 head, tail; lockdep_assert_held(&engine->active.lock); GEM_BUG_ON(USES_GUC_SUBMISSION(engine->i915)); /* * 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); GEM_TRACE("%s cs-irq head=%d, tail=%d\n", engine->name, head, tail); if (unlikely(head == tail)) return; /* * 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(); do { 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. */ GEM_TRACE("%s csb[%d]: status=0x%08x:0x%08x\n", engine->name, head, buf[2 * head + 0], buf[2 * head + 1]); switch (csb_parse(execlists, buf + 2 * head)) { case CSB_PREEMPT: /* cancel old inflight, prepare for switch */ trace_ports(execlists, "preempted", execlists->active); while (*execlists->active) execlists_schedule_out(*execlists->active++); /* fallthrough */ case CSB_PROMOTE: /* switch pending to inflight */ GEM_BUG_ON(*execlists->active); GEM_BUG_ON(!assert_pending_valid(execlists, "promote")); execlists->active = memcpy(execlists->inflight, execlists->pending, execlists_num_ports(execlists) * sizeof(*execlists->pending)); execlists->pending[0] = NULL; trace_ports(execlists, "promoted", execlists->active); if (enable_timeslice(engine)) mod_timer(&execlists->timer, jiffies + 1); if (!inject_preempt_hang(execlists)) ring_set_paused(engine, 0); break; case CSB_COMPLETE: /* 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 and CSB is processed. */ GEM_BUG_ON(!i915_request_completed(*execlists->active)); execlists_schedule_out(*execlists->active++); GEM_BUG_ON(execlists->active - execlists->inflight > execlists_num_ports(execlists)); break; case CSB_NOP: break; } } while (head != tail); execlists->csb_head = head; /* * 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. */ invalidate_csb_entries(&buf[0], &buf[num_entries - 1]); } static void __execlists_submission_tasklet(struct intel_engine_cs *const engine) { lockdep_assert_held(&engine->active.lock); process_csb(engine); if (!engine->execlists.pending[0]) execlists_dequeue(engine); } /* * Check the unread Context Status Buffers and manage the submission of new * contexts to the ELSP accordingly. */ static void execlists_submission_tasklet(unsigned long data) { struct intel_engine_cs * const engine = (struct intel_engine_cs *)data; unsigned long flags; spin_lock_irqsave(&engine->active.lock, flags); __execlists_submission_tasklet(engine); spin_unlock_irqrestore(&engine->active.lock, flags); } static void execlists_submission_timer(struct timer_list *timer) { struct intel_engine_cs *engine = from_timer(engine, timer, execlists.timer); /* Kick the tasklet for some interrupt coalescing and reset handling */ tasklet_hi_schedule(&engine->execlists.tasklet); } static void queue_request(struct intel_engine_cs *engine, struct i915_sched_node *node, int prio) { GEM_BUG_ON(!list_empty(&node->link)); list_add_tail(&node->link, i915_sched_lookup_priolist(engine, prio)); } static void __submit_queue_imm(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; if (reset_in_progress(execlists)) return; /* defer until we restart the engine following reset */ if (execlists->tasklet.func == execlists_submission_tasklet) __execlists_submission_tasklet(engine); else tasklet_hi_schedule(&execlists->tasklet); } static void submit_queue(struct intel_engine_cs *engine, const struct i915_request *rq) { struct intel_engine_execlists *execlists = &engine->execlists; if (rq_prio(rq) <= execlists->queue_priority_hint) return; execlists->queue_priority_hint = rq_prio(rq); __submit_queue_imm(engine); } 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->active.lock, flags); queue_request(engine, &request->sched, rq_prio(request)); GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root)); GEM_BUG_ON(list_empty(&request->sched.link)); submit_queue(engine, request); spin_unlock_irqrestore(&engine->active.lock, flags); } static void __execlists_context_fini(struct intel_context *ce) { intel_ring_put(ce->ring); i915_vma_put(ce->state); } static void execlists_context_destroy(struct kref *kref) { struct intel_context *ce = container_of(kref, typeof(*ce), ref); GEM_BUG_ON(!i915_active_is_idle(&ce->active)); GEM_BUG_ON(intel_context_is_pinned(ce)); if (ce->state) __execlists_context_fini(ce); intel_context_free(ce); } static void execlists_context_unpin(struct intel_context *ce) { i915_gem_context_unpin_hw_id(ce->gem_context); i915_gem_object_unpin_map(ce->state->obj); } static void __execlists_update_reg_state(struct intel_context *ce, struct intel_engine_cs *engine) { struct intel_ring *ring = ce->ring; u32 *regs = ce->lrc_reg_state; GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->head)); GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->tail)); regs[CTX_RING_BUFFER_START + 1] = i915_ggtt_offset(ring->vma); regs[CTX_RING_HEAD + 1] = ring->head; regs[CTX_RING_TAIL + 1] = ring->tail; /* RPCS */ if (engine->class == RENDER_CLASS) regs[CTX_R_PWR_CLK_STATE + 1] = intel_sseu_make_rpcs(engine->i915, &ce->sseu); } static int __execlists_context_pin(struct intel_context *ce, struct intel_engine_cs *engine) { void *vaddr; int ret; GEM_BUG_ON(!ce->gem_context->vm); ret = execlists_context_deferred_alloc(ce, engine); if (ret) goto err; GEM_BUG_ON(!ce->state); ret = intel_context_active_acquire(ce); if (ret) goto err; GEM_BUG_ON(!i915_vma_is_pinned(ce->state)); vaddr = i915_gem_object_pin_map(ce->state->obj, i915_coherent_map_type(engine->i915) | I915_MAP_OVERRIDE); if (IS_ERR(vaddr)) { ret = PTR_ERR(vaddr); goto unpin_active; } ret = i915_gem_context_pin_hw_id(ce->gem_context); if (ret) goto unpin_map; ce->lrc_desc = lrc_descriptor(ce, engine); ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE; __execlists_update_reg_state(ce, engine); return 0; unpin_map: i915_gem_object_unpin_map(ce->state->obj); unpin_active: intel_context_active_release(ce); err: return ret; } static int execlists_context_pin(struct intel_context *ce) { return __execlists_context_pin(ce, ce->engine); } static void execlists_context_reset(struct intel_context *ce) { /* * Because we emit WA_TAIL_DWORDS there may be a disparity * between our bookkeeping in ce->ring->head and ce->ring->tail and * that stored in context. As we only write new commands from * ce->ring->tail onwards, everything before that is junk. If the GPU * starts reading from its RING_HEAD from the context, it may try to * execute that junk and die. * * The contexts that are stilled pinned on resume belong to the * kernel, and are local to each engine. All other contexts will * have their head/tail sanitized upon pinning before use, so they * will never see garbage, * * So to avoid that we reset the context images upon resume. For * simplicity, we just zero everything out. */ intel_ring_reset(ce->ring, 0); __execlists_update_reg_state(ce, ce->engine); } static const struct intel_context_ops execlists_context_ops = { .pin = execlists_context_pin, .unpin = execlists_context_unpin, .enter = intel_context_enter_engine, .exit = intel_context_exit_engine, .reset = execlists_context_reset, .destroy = execlists_context_destroy, }; static int gen8_emit_init_breadcrumb(struct i915_request *rq) { u32 *cs; GEM_BUG_ON(!rq->timeline->has_initial_breadcrumb); cs = intel_ring_begin(rq, 6); if (IS_ERR(cs)) return PTR_ERR(cs); /* * Check if we have been preempted before we even get started. * * After this point i915_request_started() reports true, even if * we get preempted and so are no longer running. */ *cs++ = MI_ARB_CHECK; *cs++ = MI_NOOP; *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; *cs++ = rq->timeline->hwsp_offset; *cs++ = 0; *cs++ = rq->fence.seqno - 1; intel_ring_advance(rq, cs); /* Record the updated position of the request's payload */ rq->infix = intel_ring_offset(rq, cs); return 0; } 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->gem_context->vm); int err, i; u32 *cs; GEM_BUG_ON(intel_vgpu_active(rq->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! */ /* 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_NOOP; intel_ring_advance(rq, cs); /* Be doubly sure the LRI have landed before proceeding */ err = engine->emit_flush(rq, EMIT_FLUSH); if (err) return err; /* Re-invalidate the TLB for luck */ return engine->emit_flush(rq, EMIT_INVALIDATE); } static int execlists_request_alloc(struct i915_request *request) { int ret; GEM_BUG_ON(!intel_context_is_pinned(request->hw_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. */ /* Unconditionally invalidate GPU caches and TLBs. */ if (i915_vm_is_4lvl(request->gem_context->vm)) ret = request->engine->emit_flush(request, EMIT_INVALIDATE); else ret = emit_pdps(request); if (ret) return ret; request->reserved_space -= EXECLISTS_REQUEST_SIZE; return 0; } /* * In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after * PIPE_CONTROL instruction. This is required for the flush to happen correctly * but there is a slight complication as this is applied in WA batch where the * values are only initialized once so we cannot take register value at the * beginning and reuse it further; hence we save its value to memory, upload a * constant value with bit21 set and then we restore it back with the saved value. * To simplify the WA, a constant value is formed by using the default value * of this register. This shouldn't be a problem because we are only modifying * it for a short period and this batch in non-premptible. We can ofcourse * use additional instructions that read the actual value of the register * at that time and set our bit of interest but it makes the WA complicated. * * This WA is also required for Gen9 so extracting as a function avoids * code duplication. */ static u32 * gen8_emit_flush_coherentl3_wa(struct intel_engine_cs *engine, u32 *batch) { /* NB no one else is allowed to scribble over scratch + 256! */ *batch++ = MI_STORE_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT; *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4); *batch++ = intel_gt_scratch_offset(engine->gt, INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA); *batch++ = 0; *batch++ = MI_LOAD_REGISTER_IMM(1); *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4); *batch++ = 0x40400000 | GEN8_LQSC_FLUSH_COHERENT_LINES; batch = gen8_emit_pipe_control(batch, PIPE_CONTROL_CS_STALL | PIPE_CONTROL_DC_FLUSH_ENABLE, 0); *batch++ = MI_LOAD_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT; *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4); *batch++ = intel_gt_scratch_offset(engine->gt, INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA); *batch++ = 0; return batch; } static u32 slm_offset(struct intel_engine_cs *engine) { return intel_gt_scratch_offset(engine->gt, INTEL_GT_SCRATCH_FIELD_CLEAR_SLM_WA); } /* * Typically we only have one indirect_ctx and per_ctx batch buffer which are * initialized at the beginning and shared across all contexts but this field * helps us to have multiple batches at different offsets and select them based * on a criteria. At the moment this batch always start at the beginning of the page * and at this point we don't have multiple wa_ctx batch buffers. * * The number of WA applied are not known at the beginning; we use this field * to return the no of DWORDS written. * * It is to be noted that this batch does not contain MI_BATCH_BUFFER_END * so it adds NOOPs as padding to make it cacheline aligned. * MI_BATCH_BUFFER_END will be added to perctx batch and both of them together * makes a complete batch buffer. */ static u32 *gen8_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch) { /* WaDisableCtxRestoreArbitration:bdw,chv */ *batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; /* WaFlushCoherentL3CacheLinesAtContextSwitch:bdw */ if (IS_BROADWELL(engine->i915)) batch = gen8_emit_flush_coherentl3_wa(engine, batch); /* WaClearSlmSpaceAtContextSwitch:bdw,chv */ /* Actual scratch location is at 128 bytes offset */ batch = gen8_emit_pipe_control(batch, PIPE_CONTROL_FLUSH_L3 | PIPE_CONTROL_GLOBAL_GTT_IVB | PIPE_CONTROL_CS_STALL | PIPE_CONTROL_QW_WRITE, slm_offset(engine)); *batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; /* Pad to end of cacheline */ while ((unsigned long)batch % CACHELINE_BYTES) *batch++ = MI_NOOP; /* * MI_BATCH_BUFFER_END is not required in Indirect ctx BB because * execution depends on the length specified in terms of cache lines * in the register CTX_RCS_INDIRECT_CTX */ return batch; } struct lri { i915_reg_t reg; u32 value; }; static u32 *emit_lri(u32 *batch, const struct lri *lri, unsigned int count) { GEM_BUG_ON(!count || count > 63); *batch++ = MI_LOAD_REGISTER_IMM(count); do { *batch++ = i915_mmio_reg_offset(lri->reg); *batch++ = lri->value; } while (lri++, --count); *batch++ = MI_NOOP; return batch; } static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch) { static const struct lri lri[] = { /* WaDisableGatherAtSetShaderCommonSlice:skl,bxt,kbl,glk */ { COMMON_SLICE_CHICKEN2, __MASKED_FIELD(GEN9_DISABLE_GATHER_AT_SET_SHADER_COMMON_SLICE, 0), }, /* BSpec: 11391 */ { FF_SLICE_CHICKEN, __MASKED_FIELD(FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX, FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX), }, /* BSpec: 11299 */ { _3D_CHICKEN3, __MASKED_FIELD(_3D_CHICKEN_SF_PROVOKING_VERTEX_FIX, _3D_CHICKEN_SF_PROVOKING_VERTEX_FIX), } }; *batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; /* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */ batch = gen8_emit_flush_coherentl3_wa(engine, batch); batch = emit_lri(batch, lri, ARRAY_SIZE(lri)); /* WaMediaPoolStateCmdInWABB:bxt,glk */ if (HAS_POOLED_EU(engine->i915)) { /* * EU pool configuration is setup along with golden context * during context initialization. This value depends on * device type (2x6 or 3x6) and needs to be updated based * on which subslice is disabled especially for 2x6 * devices, however it is safe to load default * configuration of 3x6 device instead of masking off * corresponding bits because HW ignores bits of a disabled * subslice and drops down to appropriate config. Please * see render_state_setup() in i915_gem_render_state.c for * possible configurations, to avoid duplication they are * not shown here again. */ *batch++ = GEN9_MEDIA_POOL_STATE; *batch++ = GEN9_MEDIA_POOL_ENABLE; *batch++ = 0x00777000; *batch++ = 0; *batch++ = 0; *batch++ = 0; } *batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; /* Pad to end of cacheline */ while ((unsigned long)batch % CACHELINE_BYTES) *batch++ = MI_NOOP; return batch; } static u32 * gen10_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch) { int i; /* * WaPipeControlBefore3DStateSamplePattern: cnl * * Ensure the engine is idle prior to programming a * 3DSTATE_SAMPLE_PATTERN during a context restore. */ batch = gen8_emit_pipe_control(batch, PIPE_CONTROL_CS_STALL, 0); /* * WaPipeControlBefore3DStateSamplePattern says we need 4 dwords for * the PIPE_CONTROL followed by 12 dwords of 0x0, so 16 dwords in * total. However, a PIPE_CONTROL is 6 dwords long, not 4, which is * confusing. Since gen8_emit_pipe_control() already advances the * batch by 6 dwords, we advance the other 10 here, completing a * cacheline. It's not clear if the workaround requires this padding * before other commands, or if it's just the regular padding we would * already have for the workaround bb, so leave it here for now. */ for (i = 0; i < 10; i++) *batch++ = MI_NOOP; /* Pad to end of cacheline */ while ((unsigned long)batch % CACHELINE_BYTES) *batch++ = MI_NOOP; return batch; } #define CTX_WA_BB_OBJ_SIZE (PAGE_SIZE) static int lrc_setup_wa_ctx(struct intel_engine_cs *engine) { struct drm_i915_gem_object *obj; struct i915_vma *vma; int err; obj = i915_gem_object_create_shmem(engine->i915, CTX_WA_BB_OBJ_SIZE); if (IS_ERR(obj)) return PTR_ERR(obj); vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL); if (IS_ERR(vma)) { err = PTR_ERR(vma); goto err; } err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH); if (err) goto err; engine->wa_ctx.vma = vma; return 0; err: i915_gem_object_put(obj); return err; } static void lrc_destroy_wa_ctx(struct intel_engine_cs *engine) { i915_vma_unpin_and_release(&engine->wa_ctx.vma, 0); } typedef u32 *(*wa_bb_func_t)(struct intel_engine_cs *engine, u32 *batch); static int intel_init_workaround_bb(struct intel_engine_cs *engine) { struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx; struct i915_wa_ctx_bb *wa_bb[2] = { &wa_ctx->indirect_ctx, &wa_ctx->per_ctx }; wa_bb_func_t wa_bb_fn[2]; struct page *page; void *batch, *batch_ptr; unsigned int i; int ret; if (engine->class != RENDER_CLASS) return 0; switch (INTEL_GEN(engine->i915)) { case 11: return 0; case 10: wa_bb_fn[0] = gen10_init_indirectctx_bb; wa_bb_fn[1] = NULL; break; case 9: wa_bb_fn[0] = gen9_init_indirectctx_bb; wa_bb_fn[1] = NULL; break; case 8: wa_bb_fn[0] = gen8_init_indirectctx_bb; wa_bb_fn[1] = NULL; break; default: MISSING_CASE(INTEL_GEN(engine->i915)); return 0; } ret = lrc_setup_wa_ctx(engine); if (ret) { DRM_DEBUG_DRIVER("Failed to setup context WA page: %d\n", ret); return ret; } page = i915_gem_object_get_dirty_page(wa_ctx->vma->obj, 0); batch = batch_ptr = kmap_atomic(page); /* * Emit the two workaround batch buffers, recording the offset from the * start of the workaround batch buffer object for each and their * respective sizes. */ for (i = 0; i < ARRAY_SIZE(wa_bb_fn); i++) { wa_bb[i]->offset = batch_ptr - batch; if (GEM_DEBUG_WARN_ON(!IS_ALIGNED(wa_bb[i]->offset, CACHELINE_BYTES))) { ret = -EINVAL; break; } if (wa_bb_fn[i]) batch_ptr = wa_bb_fn[i](engine, batch_ptr); wa_bb[i]->size = batch_ptr - (batch + wa_bb[i]->offset); } BUG_ON(batch_ptr - batch > CTX_WA_BB_OBJ_SIZE); kunmap_atomic(batch); if (ret) lrc_destroy_wa_ctx(engine); return ret; } 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 (INTEL_GEN(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); } static bool unexpected_starting_state(struct intel_engine_cs *engine) { bool unexpected = false; if (ENGINE_READ_FW(engine, RING_MI_MODE) & STOP_RING) { DRM_DEBUG_DRIVER("STOP_RING still set in RING_MI_MODE\n"); unexpected = true; } return unexpected; } static int execlists_resume(struct intel_engine_cs *engine) { intel_engine_apply_workarounds(engine); intel_engine_apply_whitelist(engine); intel_mocs_init_engine(engine); intel_engine_reset_breadcrumbs(engine); if (GEM_SHOW_DEBUG() && unexpected_starting_state(engine)) { struct drm_printer p = drm_debug_printer(__func__); intel_engine_dump(engine, &p, NULL); } enable_execlists(engine); return 0; } static void execlists_reset_prepare(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; unsigned long flags; GEM_TRACE("%s: depth<-%d\n", engine->name, atomic_read(&execlists->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(&execlists->tasklet); GEM_BUG_ON(!reset_in_progress(execlists)); intel_engine_stop_cs(engine); /* And flush any current direct submission. */ spin_lock_irqsave(&engine->active.lock, flags); spin_unlock_irqrestore(&engine->active.lock, flags); } 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); /* * 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?) */ invalidate_csb_entries(&execlists->csb_status[0], &execlists->csb_status[reset_value]); } static struct i915_request *active_request(struct i915_request *rq) { const struct list_head * const list = &rq->engine->active.requests; const struct intel_context * const context = rq->hw_context; struct i915_request *active = NULL; list_for_each_entry_from_reverse(rq, list, sched.link) { if (i915_request_completed(rq)) break; if (rq->hw_context != context) break; active = rq; } return active; } static void __execlists_reset(struct intel_engine_cs *engine, bool stalled) { struct intel_engine_execlists * const execlists = &engine->execlists; struct intel_context *ce; struct i915_request *rq; u32 *regs; process_csb(engine); /* drain preemption events */ /* Following the reset, we need to reload the CSB read/write pointers */ reset_csb_pointers(engine); /* * 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 = execlists_active(execlists); if (!rq) return; ce = rq->hw_context; GEM_BUG_ON(i915_active_is_idle(&ce->active)); GEM_BUG_ON(!i915_vma_is_pinned(ce->state)); rq = active_request(rq); /* * Catch up with any missed context-switch interrupts. * * Ideally we would just read the remaining CSB entries now that we * know the gpu is idle. However, the CSB registers are sometimes^W * often trashed across a GPU reset! Instead we have to rely on * guessing the missed context-switch events by looking at what * requests were completed. */ execlists_cancel_port_requests(execlists); if (!rq) { ce->ring->head = ce->ring->tail; goto out_replay; } ce->ring->head = intel_ring_wrap(ce->ring, rq->head); /* * 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_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_reset_request(rq, stalled); if (!stalled) goto out_replay; /* * 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. */ regs = ce->lrc_reg_state; if (engine->pinned_default_state) { memcpy(regs, /* skip restoring the vanilla PPHWSP */ engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE, engine->context_size - PAGE_SIZE); } execlists_init_reg_state(regs, ce, engine, ce->ring); out_replay: GEM_TRACE("%s replay {head:%04x, tail:%04x\n", engine->name, ce->ring->head, ce->ring->tail); intel_ring_update_space(ce->ring); __execlists_update_reg_state(ce, engine); /* Push back any incomplete requests for replay after the reset. */ __unwind_incomplete_requests(engine); } static void execlists_reset(struct intel_engine_cs *engine, bool stalled) { unsigned long flags; GEM_TRACE("%s\n", engine->name); spin_lock_irqsave(&engine->active.lock, flags); __execlists_reset(engine, stalled); spin_unlock_irqrestore(&engine->active.lock, flags); } static void nop_submission_tasklet(unsigned long data) { /* The driver is wedged; don't process any more events. */ } static void execlists_cancel_requests(struct intel_engine_cs *engine) { struct intel_engine_execlists * const execlists = &engine->execlists; struct i915_request *rq, *rn; struct rb_node *rb; unsigned long flags; GEM_TRACE("%s\n", engine->name); /* * 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.) */ spin_lock_irqsave(&engine->active.lock, flags); __execlists_reset(engine, true); /* Mark all executing requests as skipped. */ list_for_each_entry(rq, &engine->active.requests, sched.link) { if (!i915_request_signaled(rq)) dma_fence_set_error(&rq->fence, -EIO); i915_request_mark_complete(rq); } /* Flush the queued requests to the timeline list (for retiring). */ while ((rb = rb_first_cached(&execlists->queue))) { struct i915_priolist *p = to_priolist(rb); int i; priolist_for_each_request_consume(rq, rn, p, i) { list_del_init(&rq->sched.link); __i915_request_submit(rq); dma_fence_set_error(&rq->fence, -EIO); i915_request_mark_complete(rq); } rb_erase_cached(&p->node, &execlists->queue); i915_priolist_free(p); } /* 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.active.lock); if (ve->request) { ve->request->engine = engine; __i915_request_submit(ve->request); dma_fence_set_error(&ve->request->fence, -EIO); i915_request_mark_complete(ve->request); ve->base.execlists.queue_priority_hint = INT_MIN; ve->request = NULL; } spin_unlock(&ve->base.active.lock); } /* Remaining _unready_ requests will be nop'ed when submitted */ execlists->queue_priority_hint = INT_MIN; execlists->queue = RB_ROOT_CACHED; GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet)); execlists->tasklet.func = nop_submission_tasklet; spin_unlock_irqrestore(&engine->active.lock, flags); } 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. */ GEM_BUG_ON(!reset_in_progress(execlists)); if (!RB_EMPTY_ROOT(&execlists->queue.rb_root)) execlists->tasklet.func(execlists->tasklet.data); if (__tasklet_enable(&execlists->tasklet)) /* And kick in case we missed a new request submission. */ tasklet_hi_schedule(&execlists->tasklet); GEM_TRACE("%s: depth->%d\n", engine->name, atomic_read(&execlists->tasklet.count)); } static int gen8_emit_bb_start(struct i915_request *rq, u64 offset, u32 len, const unsigned int flags) { u32 *cs; cs = intel_ring_begin(rq, 4); if (IS_ERR(cs)) return PTR_ERR(cs); /* * WaDisableCtxRestoreArbitration:bdw,chv * * We don't need to perform MI_ARB_ENABLE as often as we do (in * particular all the gen that do not need the w/a at all!), if we * took care to make sure that on every switch into this context * (both ordinary and for preemption) that arbitrartion was enabled * we would be fine. However, for gen8 there is another w/a that * requires us to not preempt inside GPGPU execution, so we keep * arbitration disabled for gen8 batches. Arbitration will be * re-enabled before we close the request * (engine->emit_fini_breadcrumb). */ *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; /* FIXME(BDW+): Address space and security selectors. */ *cs++ = MI_BATCH_BUFFER_START_GEN8 | (flags & I915_DISPATCH_SECURE ? 0 : BIT(8)); *cs++ = lower_32_bits(offset); *cs++ = upper_32_bits(offset); intel_ring_advance(rq, cs); return 0; } static int gen9_emit_bb_start(struct i915_request *rq, u64 offset, u32 len, const unsigned int flags) { u32 *cs; cs = intel_ring_begin(rq, 6); if (IS_ERR(cs)) return PTR_ERR(cs); *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; *cs++ = MI_BATCH_BUFFER_START_GEN8 | (flags & I915_DISPATCH_SECURE ? 0 : BIT(8)); *cs++ = lower_32_bits(offset); *cs++ = upper_32_bits(offset); *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE; *cs++ = MI_NOOP; intel_ring_advance(rq, cs); return 0; } 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 int gen8_emit_flush(struct i915_request *request, u32 mode) { u32 cmd, *cs; cs = intel_ring_begin(request, 4); if (IS_ERR(cs)) return PTR_ERR(cs); cmd = MI_FLUSH_DW + 1; /* We always require a command barrier so that subsequent * commands, such as breadcrumb interrupts, are strictly ordered * wrt the contents of the write cache being flushed to memory * (and thus being coherent from the CPU). */ cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW; if (mode & EMIT_INVALIDATE) { cmd |= MI_INVALIDATE_TLB; if (request->engine->class == VIDEO_DECODE_CLASS) cmd |= MI_INVALIDATE_BSD; } *cs++ = cmd; *cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT; *cs++ = 0; /* upper addr */ *cs++ = 0; /* value */ intel_ring_advance(request, cs); return 0; } static int gen8_emit_flush_render(struct i915_request *request, u32 mode) { struct intel_engine_cs *engine = request->engine; u32 scratch_addr = intel_gt_scratch_offset(engine->gt, INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH); bool vf_flush_wa = false, dc_flush_wa = false; u32 *cs, flags = 0; int len; flags |= PIPE_CONTROL_CS_STALL; if (mode & EMIT_FLUSH) { flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH; flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH; flags |= PIPE_CONTROL_DC_FLUSH_ENABLE; flags |= PIPE_CONTROL_FLUSH_ENABLE; } if (mode & EMIT_INVALIDATE) { flags |= PIPE_CONTROL_TLB_INVALIDATE; flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE; flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE; flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE; flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE; flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE; flags |= PIPE_CONTROL_QW_WRITE; flags |= PIPE_CONTROL_GLOBAL_GTT_IVB; /* * On GEN9: before VF_CACHE_INVALIDATE we need to emit a NULL * pipe control. */ if (IS_GEN(request->i915, 9)) vf_flush_wa = true; /* WaForGAMHang:kbl */ if (IS_KBL_REVID(request->i915, 0, KBL_REVID_B0)) dc_flush_wa = true; } len = 6; if (vf_flush_wa) len += 6; if (dc_flush_wa) len += 12; cs = intel_ring_begin(request, len); if (IS_ERR(cs)) return PTR_ERR(cs); if (vf_flush_wa) cs = gen8_emit_pipe_control(cs, 0, 0); if (dc_flush_wa) cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_DC_FLUSH_ENABLE, 0); cs = gen8_emit_pipe_control(cs, flags, scratch_addr); if (dc_flush_wa) cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_CS_STALL, 0); intel_ring_advance(request, cs); return 0; } /* * Reserve space for 2 NOOPs at the end of each request to be * used as a workaround for not being allowed to do lite * restore with HEAD==TAIL (WaIdleLiteRestore). */ static u32 *gen8_emit_wa_tail(struct i915_request *request, u32 *cs) { /* Ensure there's always at least one preemption point per-request. */ *cs++ = MI_ARB_CHECK; *cs++ = MI_NOOP; request->wa_tail = intel_ring_offset(request, cs); return cs; } static u32 *emit_preempt_busywait(struct i915_request *request, u32 *cs) { *cs++ = MI_SEMAPHORE_WAIT | MI_SEMAPHORE_GLOBAL_GTT | MI_SEMAPHORE_POLL | MI_SEMAPHORE_SAD_EQ_SDD; *cs++ = 0; *cs++ = intel_hws_preempt_address(request->engine); *cs++ = 0; return cs; } static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs) { cs = gen8_emit_ggtt_write(cs, request->fence.seqno, request->timeline->hwsp_offset, 0); *cs++ = MI_USER_INTERRUPT; *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; cs = emit_preempt_busywait(request, cs); request->tail = intel_ring_offset(request, cs); assert_ring_tail_valid(request->ring, request->tail); return gen8_emit_wa_tail(request, cs); } static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs) { /* XXX flush+write+CS_STALL all in one upsets gem_concurrent_blt:kbl */ cs = gen8_emit_ggtt_write_rcs(cs, request->fence.seqno, request->timeline->hwsp_offset, PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH | PIPE_CONTROL_DEPTH_CACHE_FLUSH | PIPE_CONTROL_DC_FLUSH_ENABLE); cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_FLUSH_ENABLE | PIPE_CONTROL_CS_STALL, 0); *cs++ = MI_USER_INTERRUPT; *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; cs = emit_preempt_busywait(request, cs); request->tail = intel_ring_offset(request, cs); assert_ring_tail_valid(request->ring, request->tail); return gen8_emit_wa_tail(request, cs); } static int gen8_init_rcs_context(struct i915_request *rq) { int ret; ret = intel_engine_emit_ctx_wa(rq); if (ret) return ret; ret = intel_rcs_context_init_mocs(rq); /* * Failing to program the MOCS is non-fatal.The system will not * run at peak performance. So generate an error and carry on. */ if (ret) DRM_ERROR("MOCS failed to program: expect performance issues.\n"); return intel_renderstate_emit(rq); } static void execlists_park(struct intel_engine_cs *engine) { del_timer_sync(&engine->execlists.timer); intel_engine_park(engine); } void intel_execlists_set_default_submission(struct intel_engine_cs *engine) { engine->submit_request = execlists_submit_request; engine->cancel_requests = execlists_cancel_requests; engine->schedule = i915_schedule; engine->execlists.tasklet.func = execlists_submission_tasklet; engine->reset.prepare = execlists_reset_prepare; engine->reset.reset = execlists_reset; engine->reset.finish = execlists_reset_finish; engine->park = execlists_park; engine->unpark = NULL; engine->flags |= I915_ENGINE_SUPPORTS_STATS; if (!intel_vgpu_active(engine->i915)) engine->flags |= I915_ENGINE_HAS_SEMAPHORES; if (HAS_LOGICAL_RING_PREEMPTION(engine->i915)) engine->flags |= I915_ENGINE_HAS_PREEMPTION; } static void execlists_destroy(struct intel_engine_cs *engine) { intel_engine_cleanup_common(engine); lrc_destroy_wa_ctx(engine); kfree(engine); } static void logical_ring_default_vfuncs(struct intel_engine_cs *engine) { /* Default vfuncs which can be overriden by each engine. */ engine->destroy = execlists_destroy; engine->resume = execlists_resume; engine->reset.prepare = execlists_reset_prepare; engine->reset.reset = execlists_reset; engine->reset.finish = execlists_reset_finish; engine->cops = &execlists_context_ops; engine->request_alloc = execlists_request_alloc; engine->emit_flush = gen8_emit_flush; engine->emit_init_breadcrumb = gen8_emit_init_breadcrumb; engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb; engine->set_default_submission = intel_execlists_set_default_submission; if (INTEL_GEN(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. */ } if (IS_GEN(engine->i915, 8)) engine->emit_bb_start = gen8_emit_bb_start; else engine->emit_bb_start = gen9_emit_bb_start; } static inline void logical_ring_default_irqs(struct intel_engine_cs *engine) { unsigned int shift = 0; if (INTEL_GEN(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; } int intel_execlists_submission_setup(struct intel_engine_cs *engine) { /* Intentionally left blank. */ engine->buffer = NULL; tasklet_init(&engine->execlists.tasklet, execlists_submission_tasklet, (unsigned long)engine); timer_setup(&engine->execlists.timer, execlists_submission_timer, 0); logical_ring_default_vfuncs(engine); logical_ring_default_irqs(engine); if (engine->class == RENDER_CLASS) { engine->init_context = gen8_init_rcs_context; engine->emit_flush = gen8_emit_flush_render; engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb_rcs; } return 0; } int intel_execlists_submission_init(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; int ret; ret = intel_engine_init_common(engine); if (ret) return ret; if (intel_init_workaround_bb(engine)) /* * We continue even if we fail to initialize WA batch * because we only expect rare glitches but nothing * critical to prevent us from using GPU */ DRM_ERROR("WA batch buffer initialization failed\n"); 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)); } else { execlists->submit_reg = uncore->regs + i915_mmio_reg_offset(RING_ELSP(base)); } execlists->csb_status = &engine->status_page.addr[I915_HWS_CSB_BUF0_INDEX]; execlists->csb_write = &engine->status_page.addr[intel_hws_csb_write_index(i915)]; if (INTEL_GEN(i915) < 11) execlists->csb_size = GEN8_CSB_ENTRIES; else execlists->csb_size = GEN11_CSB_ENTRIES; reset_csb_pointers(engine); return 0; } static u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *engine) { u32 indirect_ctx_offset; switch (INTEL_GEN(engine->i915)) { default: MISSING_CASE(INTEL_GEN(engine->i915)); /* fall through */ case 11: indirect_ctx_offset = GEN11_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; break; case 10: indirect_ctx_offset = GEN10_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; break; case 9: indirect_ctx_offset = GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; break; case 8: indirect_ctx_offset = GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; break; } return indirect_ctx_offset; } static void execlists_init_reg_state(u32 *regs, struct intel_context *ce, struct intel_engine_cs *engine, struct intel_ring *ring) { struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(ce->gem_context->vm); bool rcs = engine->class == RENDER_CLASS; u32 base = engine->mmio_base; /* * A context is actually a big batch buffer with several * MI_LOAD_REGISTER_IMM commands followed by (reg, value) pairs. The * values we are setting here are only for the first context restore: * on a subsequent save, the GPU will recreate this batchbuffer with new * values (including all the missing MI_LOAD_REGISTER_IMM commands that * we are not initializing here). * * Must keep consistent with virtual_update_register_offsets(). */ regs[CTX_LRI_HEADER_0] = MI_LOAD_REGISTER_IMM(rcs ? 14 : 11) | MI_LRI_FORCE_POSTED; CTX_REG(regs, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(base), _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT) | _MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH)); if (INTEL_GEN(engine->i915) < 11) { regs[CTX_CONTEXT_CONTROL + 1] |= _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT | CTX_CTRL_RS_CTX_ENABLE); } CTX_REG(regs, CTX_RING_HEAD, RING_HEAD(base), 0); CTX_REG(regs, CTX_RING_TAIL, RING_TAIL(base), 0); CTX_REG(regs, CTX_RING_BUFFER_START, RING_START(base), 0); CTX_REG(regs, CTX_RING_BUFFER_CONTROL, RING_CTL(base), RING_CTL_SIZE(ring->size) | RING_VALID); CTX_REG(regs, CTX_BB_HEAD_U, RING_BBADDR_UDW(base), 0); CTX_REG(regs, CTX_BB_HEAD_L, RING_BBADDR(base), 0); CTX_REG(regs, CTX_BB_STATE, RING_BBSTATE(base), RING_BB_PPGTT); CTX_REG(regs, CTX_SECOND_BB_HEAD_U, RING_SBBADDR_UDW(base), 0); CTX_REG(regs, CTX_SECOND_BB_HEAD_L, RING_SBBADDR(base), 0); CTX_REG(regs, CTX_SECOND_BB_STATE, RING_SBBSTATE(base), 0); if (rcs) { struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx; CTX_REG(regs, CTX_RCS_INDIRECT_CTX, RING_INDIRECT_CTX(base), 0); CTX_REG(regs, CTX_RCS_INDIRECT_CTX_OFFSET, RING_INDIRECT_CTX_OFFSET(base), 0); if (wa_ctx->indirect_ctx.size) { u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma); regs[CTX_RCS_INDIRECT_CTX + 1] = (ggtt_offset + wa_ctx->indirect_ctx.offset) | (wa_ctx->indirect_ctx.size / CACHELINE_BYTES); regs[CTX_RCS_INDIRECT_CTX_OFFSET + 1] = intel_lr_indirect_ctx_offset(engine) << 6; } CTX_REG(regs, CTX_BB_PER_CTX_PTR, RING_BB_PER_CTX_PTR(base), 0); if (wa_ctx->per_ctx.size) { u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma); regs[CTX_BB_PER_CTX_PTR + 1] = (ggtt_offset + wa_ctx->per_ctx.offset) | 0x01; } } regs[CTX_LRI_HEADER_1] = MI_LOAD_REGISTER_IMM(9) | MI_LRI_FORCE_POSTED; CTX_REG(regs, CTX_CTX_TIMESTAMP, RING_CTX_TIMESTAMP(base), 0); /* PDP values well be assigned later if needed */ CTX_REG(regs, CTX_PDP3_UDW, GEN8_RING_PDP_UDW(base, 3), 0); CTX_REG(regs, CTX_PDP3_LDW, GEN8_RING_PDP_LDW(base, 3), 0); CTX_REG(regs, CTX_PDP2_UDW, GEN8_RING_PDP_UDW(base, 2), 0); CTX_REG(regs, CTX_PDP2_LDW, GEN8_RING_PDP_LDW(base, 2), 0); CTX_REG(regs, CTX_PDP1_UDW, GEN8_RING_PDP_UDW(base, 1), 0); CTX_REG(regs, CTX_PDP1_LDW, GEN8_RING_PDP_LDW(base, 1), 0); CTX_REG(regs, CTX_PDP0_UDW, GEN8_RING_PDP_UDW(base, 0), 0); CTX_REG(regs, CTX_PDP0_LDW, GEN8_RING_PDP_LDW(base, 0), 0); if (i915_vm_is_4lvl(&ppgtt->vm)) { /* 64b PPGTT (48bit canonical) * PDP0_DESCRIPTOR contains the base address to PML4 and * other PDP Descriptors are ignored. */ ASSIGN_CTX_PML4(ppgtt, regs); } else { ASSIGN_CTX_PDP(ppgtt, regs, 3); ASSIGN_CTX_PDP(ppgtt, regs, 2); ASSIGN_CTX_PDP(ppgtt, regs, 1); ASSIGN_CTX_PDP(ppgtt, regs, 0); } if (rcs) { regs[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1); CTX_REG(regs, CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE, 0); i915_oa_init_reg_state(engine, ce, regs); } regs[CTX_END] = MI_BATCH_BUFFER_END; if (INTEL_GEN(engine->i915) >= 10) regs[CTX_END] |= BIT(0); } static int populate_lr_context(struct intel_context *ce, struct drm_i915_gem_object *ctx_obj, struct intel_engine_cs *engine, struct intel_ring *ring) { void *vaddr; u32 *regs; int ret; vaddr = i915_gem_object_pin_map(ctx_obj, I915_MAP_WB); if (IS_ERR(vaddr)) { ret = PTR_ERR(vaddr); DRM_DEBUG_DRIVER("Could not map object pages! (%d)\n", ret); return ret; } if (engine->default_state) { /* * We only want to copy over the template context state; * skipping over the headers reserved for GuC communication, * leaving those as zero. */ const unsigned long start = LRC_HEADER_PAGES * PAGE_SIZE; void *defaults; defaults = i915_gem_object_pin_map(engine->default_state, I915_MAP_WB); if (IS_ERR(defaults)) { ret = PTR_ERR(defaults); goto err_unpin_ctx; } memcpy(vaddr + start, defaults + start, engine->context_size); i915_gem_object_unpin_map(engine->default_state); } /* The second page of the context object contains some fields which must * be set up prior to the first execution. */ regs = vaddr + LRC_STATE_PN * PAGE_SIZE; execlists_init_reg_state(regs, ce, engine, ring); if (!engine->default_state) regs[CTX_CONTEXT_CONTROL + 1] |= _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT); ret = 0; err_unpin_ctx: __i915_gem_object_flush_map(ctx_obj, LRC_HEADER_PAGES * PAGE_SIZE, engine->context_size); i915_gem_object_unpin_map(ctx_obj); return ret; } static struct intel_timeline * get_timeline(struct i915_gem_context *ctx, struct intel_gt *gt) { if (ctx->timeline) return intel_timeline_get(ctx->timeline); else return intel_timeline_create(gt, NULL); } static int execlists_context_deferred_alloc(struct intel_context *ce, struct intel_engine_cs *engine) { struct drm_i915_gem_object *ctx_obj; struct i915_vma *vma; u32 context_size; struct intel_ring *ring; struct intel_timeline *timeline; int ret; if (ce->state) return 0; context_size = round_up(engine->context_size, I915_GTT_PAGE_SIZE); /* * Before the actual start of the context image, we insert a few pages * for our own use and for sharing with the GuC. */ context_size += LRC_HEADER_PAGES * PAGE_SIZE; ctx_obj = i915_gem_object_create_shmem(engine->i915, context_size); if (IS_ERR(ctx_obj)) return PTR_ERR(ctx_obj); vma = i915_vma_instance(ctx_obj, &engine->gt->ggtt->vm, NULL); if (IS_ERR(vma)) { ret = PTR_ERR(vma); goto error_deref_obj; } timeline = get_timeline(ce->gem_context, engine->gt); if (IS_ERR(timeline)) { ret = PTR_ERR(timeline); goto error_deref_obj; } ring = intel_engine_create_ring(engine, timeline, ce->gem_context->ring_size); intel_timeline_put(timeline); if (IS_ERR(ring)) { ret = PTR_ERR(ring); goto error_deref_obj; } ret = populate_lr_context(ce, ctx_obj, engine, ring); if (ret) { DRM_DEBUG_DRIVER("Failed to populate LRC: %d\n", ret); goto error_ring_free; } ce->ring = ring; ce->state = vma; return 0; error_ring_free: intel_ring_put(ring); error_deref_obj: i915_gem_object_put(ctx_obj); return ret; } static struct list_head *virtual_queue(struct virtual_engine *ve) { return &ve->base.execlists.default_priolist.requests[0]; } static void virtual_context_destroy(struct kref *kref) { struct virtual_engine *ve = container_of(kref, typeof(*ve), context.ref); unsigned int n; GEM_BUG_ON(!list_empty(virtual_queue(ve))); GEM_BUG_ON(ve->request); GEM_BUG_ON(ve->context.inflight); 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->active.lock); /* Detachment is lazily performed in the execlists tasklet */ if (!RB_EMPTY_NODE(node)) rb_erase_cached(node, &sibling->execlists.virtual); spin_unlock_irq(&sibling->active.lock); } GEM_BUG_ON(__tasklet_is_scheduled(&ve->base.execlists.tasklet)); if (ve->context.state) __execlists_context_fini(&ve->context); kfree(ve->bonds); kfree(ve); } 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) return; swap(ve->siblings[swp], ve->siblings[0]); virtual_update_register_offsets(ve->context.lrc_reg_state, ve->siblings[0]); } static int virtual_context_pin(struct intel_context *ce) { struct virtual_engine *ve = container_of(ce, typeof(*ve), context); int err; /* Note: we must use a real engine class for setting up reg state */ err = __execlists_context_pin(ce, ve->siblings[0]); if (err) return err; virtual_engine_initial_hint(ve); return 0; } 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]); } static void virtual_context_exit(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_put(ve->siblings[n]); } static const struct intel_context_ops virtual_context_ops = { .pin = virtual_context_pin, .unpin = execlists_context_unpin, .enter = virtual_context_enter, .exit = virtual_context_exit, .destroy = virtual_context_destroy, }; 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_skip(rq, -ENODEV); mask = ve->siblings[0]->mask; } GEM_TRACE("%s: rq=%llx:%lld, mask=%x, prio=%d\n", ve->base.name, rq->fence.context, rq->fence.seqno, mask, ve->base.execlists.queue_priority_hint); return mask; } static void virtual_submission_tasklet(unsigned long data) { struct virtual_engine * const ve = (struct virtual_engine *)data; const int prio = ve->base.execlists.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; local_irq_disable(); for (n = 0; READ_ONCE(ve->request) && n < ve->num_siblings; n++) { struct intel_engine_cs *sibling = ve->siblings[n]; struct ve_node * const node = &ve->nodes[sibling->id]; struct rb_node **parent, *rb; bool first; if (unlikely(!(mask & sibling->mask))) { if (!RB_EMPTY_NODE(&node->rb)) { spin_lock(&sibling->active.lock); rb_erase_cached(&node->rb, &sibling->execlists.virtual); RB_CLEAR_NODE(&node->rb); spin_unlock(&sibling->active.lock); } continue; } spin_lock(&sibling->active.lock); if (!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->execlists.queue_priority_hint) { sibling->execlists.queue_priority_hint = prio; tasklet_hi_schedule(&sibling->execlists.tasklet); } spin_unlock(&sibling->active.lock); } local_irq_enable(); } static void virtual_submit_request(struct i915_request *rq) { struct virtual_engine *ve = to_virtual_engine(rq->engine); GEM_TRACE("%s: rq=%llx:%lld\n", ve->base.name, rq->fence.context, rq->fence.seqno); GEM_BUG_ON(ve->base.submit_request != virtual_submit_request); GEM_BUG_ON(ve->request); GEM_BUG_ON(!list_empty(virtual_queue(ve))); ve->base.execlists.queue_priority_hint = rq_prio(rq); WRITE_ONCE(ve->request, rq); list_move_tail(&rq->sched.link, virtual_queue(ve)); tasklet_schedule(&ve->base.execlists.tasklet); } static struct ve_bond * virtual_find_bond(struct virtual_engine *ve, const struct intel_engine_cs *master) { int i; for (i = 0; i < ve->num_bonds; i++) { if (ve->bonds[i].master == master) return &ve->bonds[i]; } return NULL; } static void virtual_bond_execute(struct i915_request *rq, struct dma_fence *signal) { struct virtual_engine *ve = to_virtual_engine(rq->engine); struct ve_bond *bond; bond = virtual_find_bond(ve, to_request(signal)->engine); if (bond) { intel_engine_mask_t old, new, cmp; cmp = READ_ONCE(rq->execution_mask); do { old = cmp; new = cmp & bond->sibling_mask; } while ((cmp = cmpxchg(&rq->execution_mask, old, new)) != old); } } struct intel_context * intel_execlists_create_virtual(struct i915_gem_context *ctx, struct intel_engine_cs **siblings, unsigned int count) { struct virtual_engine *ve; unsigned int n; int err; if (count == 0) return ERR_PTR(-EINVAL); if (count == 1) return intel_context_create(ctx, siblings[0]); ve = kzalloc(struct_size(ve, siblings, count), GFP_KERNEL); if (!ve) return ERR_PTR(-ENOMEM); ve->base.i915 = ctx->i915; ve->base.gt = siblings[0]->gt; 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.flags = I915_ENGINE_IS_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_active(&ve->base, ENGINE_VIRTUAL); intel_engine_init_execlists(&ve->base); ve->base.cops = &virtual_context_ops; ve->base.request_alloc = execlists_request_alloc; ve->base.schedule = i915_schedule; ve->base.submit_request = virtual_submit_request; ve->base.bond_execute = virtual_bond_execute; INIT_LIST_HEAD(virtual_queue(ve)); ve->base.execlists.queue_priority_hint = INT_MIN; tasklet_init(&ve->base.execlists.tasklet, virtual_submission_tasklet, (unsigned long)ve); intel_context_init(&ve->context, ctx, &ve->base); 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->execlists.tasklet.func != 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; /* * 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.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; } return &ve->context; err_put: intel_context_put(&ve->context); return ERR_PTR(err); } struct intel_context * intel_execlists_clone_virtual(struct i915_gem_context *ctx, struct intel_engine_cs *src) { struct virtual_engine *se = to_virtual_engine(src); struct intel_context *dst; dst = intel_execlists_create_virtual(ctx, se->siblings, se->num_siblings); if (IS_ERR(dst)) return dst; if (se->num_bonds) { struct virtual_engine *de = to_virtual_engine(dst->engine); de->bonds = kmemdup(se->bonds, sizeof(*se->bonds) * se->num_bonds, GFP_KERNEL); if (!de->bonds) { intel_context_put(dst); return ERR_PTR(-ENOMEM); } de->num_bonds = se->num_bonds; } return dst; } int intel_virtual_engine_attach_bond(struct intel_engine_cs *engine, const struct intel_engine_cs *master, const struct intel_engine_cs *sibling) { struct virtual_engine *ve = to_virtual_engine(engine); struct ve_bond *bond; int n; /* Sanity check the sibling is part of the virtual engine */ for (n = 0; n < ve->num_siblings; n++) if (sibling == ve->siblings[n]) break; if (n == ve->num_siblings) return -EINVAL; bond = virtual_find_bond(ve, master); if (bond) { bond->sibling_mask |= sibling->mask; return 0; } bond = krealloc(ve->bonds, sizeof(*bond) * (ve->num_bonds + 1), GFP_KERNEL); if (!bond) return -ENOMEM; bond[ve->num_bonds].master = master; bond[ve->num_bonds].sibling_mask = sibling->mask; ve->bonds = bond; ve->num_bonds++; return 0; } void intel_execlists_show_requests(struct intel_engine_cs *engine, struct drm_printer *m, void (*show_request)(struct drm_printer *m, struct i915_request *rq, const char *prefix), unsigned int max) { const struct intel_engine_execlists *execlists = &engine->execlists; struct i915_request *rq, *last; unsigned long flags; unsigned int count; struct rb_node *rb; spin_lock_irqsave(&engine->active.lock, flags); last = NULL; count = 0; list_for_each_entry(rq, &engine->active.requests, sched.link) { if (count++ < max - 1) show_request(m, rq, "\t\tE "); 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\tE "); } last = NULL; count = 0; if (execlists->queue_priority_hint != INT_MIN) drm_printf(m, "\t\tQueue priority hint: %d\n", execlists->queue_priority_hint); for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) { struct i915_priolist *p = rb_entry(rb, typeof(*p), node); int i; priolist_for_each_request(rq, p, i) { if (count++ < max - 1) show_request(m, rq, "\t\tQ "); 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\tQ "); } 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\tV "); 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\tV "); } spin_unlock_irqrestore(&engine->active.lock, flags); } void intel_lr_context_reset(struct intel_engine_cs *engine, struct intel_context *ce, u32 head, bool scrub) { /* * 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. */ if (scrub) { u32 *regs = ce->lrc_reg_state; if (engine->pinned_default_state) { memcpy(regs, /* skip restoring the vanilla PPHWSP */ engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE, engine->context_size - PAGE_SIZE); } execlists_init_reg_state(regs, ce, engine, ce->ring); } /* Rerun the request; its payload has been neutered (if guilty). */ ce->ring->head = head; intel_ring_update_space(ce->ring); __execlists_update_reg_state(ce, engine); } #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) #include "selftest_lrc.c" #endif