diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_lrc.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_lrc.c | 3614 |
1 files changed, 3614 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c new file mode 100644 index 000000000000..1f7bee0cae0c --- /dev/null +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -0,0 +1,3614 @@ +/* + * 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 <ben@bwidawsk.net> + * Michel Thierry <michel.thierry@intel.com> + * Thomas Daniel <thomas.daniel@intel.com> + * Oscar Mateo <oscar.mateo@intel.com> + * + */ + +/** + * DOC: Logical Rings, Logical Ring Contexts and Execlists + * + * Motivation: + * GEN8 brings an expansion of the HW contexts: "Logical Ring Contexts". + * These expanded contexts enable a number of new abilities, especially + * "Execlists" (also implemented in this file). + * + * One of the main differences with the legacy HW contexts is that logical + * ring contexts incorporate many more things to the context's state, like + * PDPs or ringbuffer control registers: + * + * The reason why PDPs are included in the context is straightforward: as + * PPGTTs (per-process GTTs) are actually per-context, having the PDPs + * contained there mean you don't need to do a ppgtt->switch_mm yourself, + * instead, the GPU will do it for you on the context switch. + * + * But, what about the ringbuffer control registers (head, tail, etc..)? + * shouldn't we just need a set of those per engine command streamer? This is + * where the name "Logical Rings" starts to make sense: by virtualizing the + * rings, the engine cs shifts to a new "ring buffer" with every context + * switch. When you want to submit a workload to the GPU you: A) choose your + * context, B) find its appropriate virtualized ring, C) write commands to it + * and then, finally, D) tell the GPU to switch to that context. + * + * Instead of the legacy MI_SET_CONTEXT, the way you tell the GPU to switch + * to a contexts is via a context execution list, ergo "Execlists". + * + * LRC implementation: + * Regarding the creation of contexts, we have: + * + * - One global default context. + * - One local default context for each opened fd. + * - One local extra context for each context create ioctl call. + * + * Now that ringbuffers belong per-context (and not per-engine, like before) + * and that contexts are uniquely tied to a given engine (and not reusable, + * like before) we need: + * + * - One ringbuffer per-engine inside each context. + * - One backing object per-engine inside each context. + * + * The global default context starts its life with these new objects fully + * allocated and populated. The local default context for each opened fd is + * more complex, because we don't know at creation time which engine is going + * to use them. To handle this, we have implemented a deferred creation of LR + * contexts: + * + * The local context starts its life as a hollow or blank holder, that only + * gets populated for a given engine once we receive an execbuffer. If later + * on we receive another execbuffer ioctl for the same context but a different + * engine, we allocate/populate a new ringbuffer and context backing object and + * so on. + * + * Finally, regarding local contexts created using the ioctl call: as they are + * only allowed with the render ring, we can allocate & populate them right + * away (no need to defer anything, at least for now). + * + * Execlists implementation: + * Execlists are the new method by which, on gen8+ hardware, workloads are + * submitted for execution (as opposed to the legacy, ringbuffer-based, method). + * This method works as follows: + * + * When a request is committed, its commands (the BB start and any leading or + * trailing commands, like the seqno breadcrumbs) are placed in the ringbuffer + * for the appropriate context. The tail pointer in the hardware context is not + * updated at this time, but instead, kept by the driver in the ringbuffer + * structure. A structure representing this request is added to a request queue + * for the appropriate engine: this structure contains a copy of the context's + * tail after the request was written to the ring buffer and a pointer to the + * context itself. + * + * If the engine's request queue was empty before the request was added, the + * queue is processed immediately. Otherwise the queue will be processed during + * a context switch interrupt. In any case, elements on the queue will get sent + * (in pairs) to the GPU's ExecLists Submit Port (ELSP, for short) with a + * globally unique 20-bits submission ID. + * + * When execution of a request completes, the GPU updates the context status + * buffer with a context complete event and generates a context switch interrupt. + * During the interrupt handling, the driver examines the events in the buffer: + * for each context complete event, if the announced ID matches that on the head + * of the request queue, then that request is retired and removed from the queue. + * + * After processing, if any requests were retired and the queue is not empty + * then a new execution list can be submitted. The two requests at the front of + * the queue are next to be submitted but since a context may not occur twice in + * an execution list, if subsequent requests have the same ID as the first then + * the two requests must be combined. This is done simply by discarding requests + * at the head of the queue until either only one requests is left (in which case + * we use a NULL second context) or the first two requests have unique IDs. + * + * By always executing the first two requests in the queue the driver ensures + * that the GPU is kept as busy as possible. In the case where a single context + * completes but a second context is still executing, the request for this second + * context will be at the head of the queue when we remove the first one. This + * request will then be resubmitted along with a new request for a different context, + * which will cause the hardware to continue executing the second request and queue + * the new request (the GPU detects the condition of a context getting preempted + * with the same context and optimizes the context switch flow by not doing + * preemption, but just sampling the new tail pointer). + * + */ +#include <linux/interrupt.h> + +#include "i915_drv.h" +#include "i915_gem_render_state.h" +#include "i915_vgpu.h" +#include "intel_engine_pm.h" +#include "intel_lrc_reg.h" +#include "intel_mocs.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) + +/* 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 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); + + /* + * 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 */ + 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; + + if (!engine->preempt_context) + return false; + + if (i915_request_completed(rq)) + return false; + + /* + * Check if the current priority hint merits a preemption attempt. + * + * We record the highest value priority we saw during rescheduling + * prior to this dequeue, therefore we know that if it is strictly + * less than the current tail of ESLP[0], we do not need to force + * a preempt-to-idle cycle. + * + * However, the priority hint is a mere hint that we may need to + * preempt. If that hint is stale or we may be trying to preempt + * ourselves, ignore the request. + */ + 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->link, &engine->timeline.requests) && + rq_prio(list_next_entry(rq, 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) +{ + const struct intel_engine_execlists *execlists = + &prev->engine->execlists; + + /* + * 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 (port_request(execlists->port) == 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->timeline.lock); + + list_for_each_entry_safe_reverse(rq, rn, + &engine->timeline.requests, + link) { + struct intel_engine_cs *owner; + + if (i915_request_completed(rq)) + break; + + __i915_request_unsubmit(rq); + unwind_wa_tail(rq); + + GEM_BUG_ON(rq->hw_context->active); + + /* + * 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_add(&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); +} + +inline void +execlists_user_begin(struct intel_engine_execlists *execlists, + const struct execlist_port *port) +{ + execlists_set_active_once(execlists, EXECLISTS_ACTIVE_USER); +} + +inline void +execlists_user_end(struct intel_engine_execlists *execlists) +{ + execlists_clear_active(execlists, EXECLISTS_ACTIVE_USER); +} + +static inline void +execlists_context_schedule_in(struct i915_request *rq) +{ + GEM_BUG_ON(rq->hw_context->active); + + execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); + intel_engine_context_in(rq->engine); + rq->hw_context->active = rq->engine; +} + +static void kick_siblings(struct i915_request *rq) +{ + struct virtual_engine *ve = to_virtual_engine(rq->hw_context->engine); + 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_context_schedule_out(struct i915_request *rq, unsigned long status) +{ + rq->hw_context->active = NULL; + intel_engine_context_out(rq->engine); + execlists_context_status_change(rq, status); + trace_i915_request_out(rq); + + /* + * If this is part of a virtual engine, its next request may have + * been blocked waiting for access to the active context. We have + * to kick all the siblings again in case we need to switch (e.g. + * the next request is not runnable on this engine). Hopefully, + * we will already have submitted the next request before the + * tasklet runs and do not need to rebuild each virtual tree + * and kick everyone again. + */ + if (rq->engine != rq->hw_context->engine) + kick_siblings(rq); +} + +static u64 execlists_update_context(struct i915_request *rq) +{ + struct intel_context *ce = rq->hw_context; + + 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(); + return ce->lrc_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 void execlists_submit_ports(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists *execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + unsigned int n; + + /* + * 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_wakeref_active(&engine->wakeref)); + + /* + * 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; + unsigned int count; + u64 desc; + + rq = port_unpack(&port[n], &count); + if (rq) { + GEM_BUG_ON(count > !n); + if (!count++) + execlists_context_schedule_in(rq); + port_set(&port[n], port_pack(rq, count)); + desc = execlists_update_context(rq); + GEM_DEBUG_EXEC(port[n].context_id = upper_32_bits(desc)); + + GEM_TRACE("%s in[%d]: ctx=%d.%d, fence %llx:%lld (current %d), prio=%d\n", + engine->name, n, + port[n].context_id, count, + rq->fence.context, rq->fence.seqno, + hwsp_seqno(rq), + rq_prio(rq)); + } else { + GEM_BUG_ON(!n); + desc = 0; + } + + write_desc(execlists, desc, n); + } + + /* we need to manually load the submit queue */ + if (execlists->ctrl_reg) + writel(EL_CTRL_LOAD, execlists->ctrl_reg); + + execlists_clear_active(execlists, EXECLISTS_ACTIVE_HWACK); +} + +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(!assert_priority_queue(prev, next)); + + if (!can_merge_ctx(prev->hw_context, next->hw_context)) + return false; + + return true; +} + +static void port_assign(struct execlist_port *port, struct i915_request *rq) +{ + GEM_BUG_ON(rq == port_request(port)); + + if (port_isset(port)) + i915_request_put(port_request(port)); + + port_set(port, port_pack(i915_request_get(rq), port_count(port))); +} + +static void inject_preempt_context(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists *execlists = &engine->execlists; + struct intel_context *ce = engine->preempt_context; + unsigned int n; + + GEM_BUG_ON(execlists->preempt_complete_status != + upper_32_bits(ce->lrc_desc)); + + /* + * Switch to our empty preempt context so + * the state of the GPU is known (idle). + */ + GEM_TRACE("%s\n", engine->name); + for (n = execlists_num_ports(execlists); --n; ) + write_desc(execlists, 0, n); + + write_desc(execlists, ce->lrc_desc, n); + + /* we need to manually load the submit queue */ + if (execlists->ctrl_reg) + writel(EL_CTRL_LOAD, execlists->ctrl_reg); + + execlists_clear_active(execlists, EXECLISTS_ACTIVE_HWACK); + execlists_set_active(execlists, EXECLISTS_ACTIVE_PREEMPT); + + (void)I915_SELFTEST_ONLY(execlists->preempt_hang.count++); +} + +static void complete_preempt_context(struct intel_engine_execlists *execlists) +{ + GEM_BUG_ON(!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT)); + + if (inject_preempt_hang(execlists)) + return; + + execlists_cancel_port_requests(execlists); + __unwind_incomplete_requests(container_of(execlists, + struct intel_engine_cs, + execlists)); +} + +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 *active; + + 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. + */ + active = READ_ONCE(ve->context.active); + if (active && active != 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 void execlists_dequeue(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + const struct execlist_port * const last_port = + &execlists->port[execlists->port_mask]; + struct i915_request *last = port_request(port); + 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 (last) { + /* + * Don't resubmit or switch until all outstanding + * preemptions (lite-restore) are seen. Then we + * know the next preemption status we see corresponds + * to this ELSP update. + */ + GEM_BUG_ON(!execlists_is_active(execlists, + EXECLISTS_ACTIVE_USER)); + GEM_BUG_ON(!port_count(&port[0])); + + /* + * If we write to ELSP a second time before the HW has had + * a chance to respond to the previous write, we can confuse + * the HW and hit "undefined behaviour". After writing to ELSP, + * we must then wait until we see a context-switch event from + * the HW to indicate that it has had a chance to respond. + */ + if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_HWACK)) + return; + + if (need_preempt(engine, last, rb)) { + inject_preempt_context(engine); + return; + } + + /* + * In theory, we could coalesce more requests onto + * the second port (the first port is active, with + * no preemptions pending). However, that means we + * then have to deal with the possible lite-restore + * of the second port (as we submit the ELSP, there + * may be a context-switch) but also we may complete + * the resubmission before the context-switch. Ergo, + * coalescing onto the second port will cause a + * preemption event, but we cannot predict whether + * that will affect port[0] or port[1]. + * + * If the second port is already active, we can wait + * until the next context-switch before contemplating + * new requests. The GPU will be busy and we should be + * able to resubmit the new ELSP before it idles, + * avoiding pipeline bubbles (momentary pauses where + * the driver is unable to keep up the supply of new + * work). However, we have to double check that the + * priorities of the ports haven't been switch. + */ + if (port_count(&port[1])) + 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.timeline.lock); + + rq = ve->request; + if (unlikely(!rq)) { /* lost the race to a sibling */ + spin_unlock(&ve->base.timeline.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.timeline.lock); + rb = rb_next(rb); + continue; + } + + if (last && !can_merge_rq(last, rq)) { + spin_unlock(&ve->base.timeline.lock); + return; /* leave this rq for another engine */ + } + + 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.active)); + 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); + trace_i915_request_in(rq, port_index(port, execlists)); + submit = true; + last = rq; + } + + spin_unlock(&ve->base.timeline.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) { + /* + * 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; + + + if (submit) + port_assign(port, last); + port++; + + GEM_BUG_ON(port_isset(port)); + } + + list_del_init(&rq->sched.link); + + __i915_request_submit(rq); + trace_i915_request_in(rq, port_index(port, execlists)); + + last = rq; + submit = true; + } + + 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); + + if (submit) { + port_assign(port, last); + execlists_submit_ports(engine); + } + + /* We must always keep the beast fed if we have work piled up */ + GEM_BUG_ON(rb_first_cached(&execlists->queue) && + !port_isset(execlists->port)); + + /* Re-evaluate the executing context setup after each preemptive kick */ + if (last) + execlists_user_begin(execlists, execlists->port); + + /* If the engine is now idle, so should be the flag; and vice versa. */ + GEM_BUG_ON(execlists_is_active(&engine->execlists, + EXECLISTS_ACTIVE_USER) == + !port_isset(engine->execlists.port)); +} + +void +execlists_cancel_port_requests(struct intel_engine_execlists * const execlists) +{ + struct execlist_port *port = execlists->port; + unsigned int num_ports = execlists_num_ports(execlists); + + while (num_ports-- && port_isset(port)) { + struct i915_request *rq = port_request(port); + + GEM_TRACE("%s:port%u fence %llx:%lld, (current %d)\n", + rq->engine->name, + (unsigned int)(port - execlists->port), + rq->fence.context, rq->fence.seqno, + hwsp_seqno(rq)); + + GEM_BUG_ON(!execlists->active); + execlists_context_schedule_out(rq, + i915_request_completed(rq) ? + INTEL_CONTEXT_SCHEDULE_OUT : + INTEL_CONTEXT_SCHEDULE_PREEMPTED); + + i915_request_put(rq); + + memset(port, 0, sizeof(*port)); + port++; + } + + execlists_clear_all_active(execlists); +} + +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)); +} + +static void process_csb(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + const u32 * const buf = execlists->csb_status; + const u8 num_entries = execlists->csb_size; + u8 head, tail; + + lockdep_assert_held(&engine->timeline.lock); + + /* + * 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 { + struct i915_request *rq; + unsigned int status; + unsigned int count; + + 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, active=0x%x\n", + engine->name, head, + buf[2 * head + 0], buf[2 * head + 1], + execlists->active); + + status = buf[2 * head]; + if (status & (GEN8_CTX_STATUS_IDLE_ACTIVE | + GEN8_CTX_STATUS_PREEMPTED)) + execlists_set_active(execlists, + EXECLISTS_ACTIVE_HWACK); + if (status & GEN8_CTX_STATUS_ACTIVE_IDLE) + execlists_clear_active(execlists, + EXECLISTS_ACTIVE_HWACK); + + if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK)) + continue; + + /* We should never get a COMPLETED | IDLE_ACTIVE! */ + GEM_BUG_ON(status & GEN8_CTX_STATUS_IDLE_ACTIVE); + + if (status & GEN8_CTX_STATUS_COMPLETE && + buf[2*head + 1] == execlists->preempt_complete_status) { + GEM_TRACE("%s preempt-idle\n", engine->name); + complete_preempt_context(execlists); + continue; + } + + if (status & GEN8_CTX_STATUS_PREEMPTED && + execlists_is_active(execlists, + EXECLISTS_ACTIVE_PREEMPT)) + continue; + + GEM_BUG_ON(!execlists_is_active(execlists, + EXECLISTS_ACTIVE_USER)); + + rq = port_unpack(port, &count); + GEM_TRACE("%s out[0]: ctx=%d.%d, fence %llx:%lld (current %d), prio=%d\n", + engine->name, + port->context_id, count, + rq ? rq->fence.context : 0, + rq ? rq->fence.seqno : 0, + rq ? hwsp_seqno(rq) : 0, + rq ? rq_prio(rq) : 0); + + /* Check the context/desc id for this event matches */ + GEM_DEBUG_BUG_ON(buf[2 * head + 1] != port->context_id); + + GEM_BUG_ON(count == 0); + if (--count == 0) { + /* + * On the final event corresponding to the + * submission of this context, we expect either + * an element-switch event or a completion + * event (and on completion, the active-idle + * marker). No more preemptions, lite-restore + * or otherwise. + */ + GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED); + GEM_BUG_ON(port_isset(&port[1]) && + !(status & GEN8_CTX_STATUS_ELEMENT_SWITCH)); + GEM_BUG_ON(!port_isset(&port[1]) && + !(status & GEN8_CTX_STATUS_ACTIVE_IDLE)); + + /* + * 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(rq)); + + execlists_context_schedule_out(rq, + INTEL_CONTEXT_SCHEDULE_OUT); + i915_request_put(rq); + + GEM_TRACE("%s completed ctx=%d\n", + engine->name, port->context_id); + + port = execlists_port_complete(execlists, port); + if (port_isset(port)) + execlists_user_begin(execlists, port); + else + execlists_user_end(execlists); + } else { + port_set(port, port_pack(rq, count)); + } + } 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->timeline.lock); + + process_csb(engine); + if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT)) + 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; + + GEM_TRACE("%s awake?=%d, active=%x\n", + engine->name, + !!intel_wakeref_active(&engine->wakeref), + engine->execlists.active); + + spin_lock_irqsave(&engine->timeline.lock, flags); + __execlists_submission_tasklet(engine); + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static void queue_request(struct intel_engine_cs *engine, + struct i915_sched_node *node, + int prio) +{ + 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, int prio) +{ + if (prio > engine->execlists.queue_priority_hint) { + engine->execlists.queue_priority_hint = prio; + __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->timeline.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, rq_prio(request)); + + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static void __execlists_context_fini(struct intel_context *ce) +{ + intel_ring_put(ce->ring); + + GEM_BUG_ON(i915_gem_object_is_active(ce->state->obj)); + i915_gem_object_put(ce->state->obj); +} + +static void execlists_context_destroy(struct kref *kref) +{ + struct intel_context *ce = container_of(kref, typeof(*ce), ref); + + GEM_BUG_ON(intel_context_is_pinned(ce)); + + if (ce->state) + __execlists_context_fini(ce); + + intel_context_free(ce); +} + +static int __context_pin(struct i915_vma *vma) +{ + unsigned int flags; + int err; + + flags = PIN_GLOBAL | PIN_HIGH; + flags |= PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma); + + err = i915_vma_pin(vma, 0, 0, flags); + if (err) + return err; + + vma->obj->pin_global++; + vma->obj->mm.dirty = true; + + return 0; +} + +static void __context_unpin(struct i915_vma *vma) +{ + vma->obj->pin_global--; + __i915_vma_unpin(vma); +} + +static void execlists_context_unpin(struct intel_context *ce) +{ + struct intel_engine_cs *engine; + + /* + * The tasklet may still be using a pointer to our state, via an + * old request. However, since we know we only unpin the context + * on retirement of the following request, we know that the last + * request referencing us will have had a completion CS interrupt. + * If we see that it is still active, it means that the tasklet hasn't + * had the chance to run yet; let it run before we teardown the + * reference it may use. + */ + engine = READ_ONCE(ce->active); + if (unlikely(engine)) { + unsigned long flags; + + spin_lock_irqsave(&engine->timeline.lock, flags); + process_csb(engine); + spin_unlock_irqrestore(&engine->timeline.lock, flags); + + GEM_BUG_ON(READ_ONCE(ce->active)); + } + + i915_gem_context_unpin_hw_id(ce->gem_context); + + intel_ring_unpin(ce->ring); + + i915_gem_object_unpin_map(ce->state->obj); + __context_unpin(ce->state); +} + +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->ppgtt); + + ret = execlists_context_deferred_alloc(ce, engine); + if (ret) + goto err; + GEM_BUG_ON(!ce->state); + + ret = __context_pin(ce->state); + if (ret) + goto err; + + 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_vma; + } + + ret = intel_ring_pin(ce->ring); + if (ret) + goto unpin_map; + + ret = i915_gem_context_pin_hw_id(ce->gem_context); + if (ret) + goto unpin_ring; + + 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_ring: + intel_ring_unpin(ce->ring); +unpin_map: + i915_gem_object_unpin_map(ce->state->obj); +unpin_vma: + __context_unpin(ce->state); +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_hw_ppgtt * const ppgtt = rq->gem_context->ppgtt; + 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->ppgtt->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++ = i915_scratch_offset(engine->i915) + 256; + *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++ = i915_scratch_offset(engine->i915) + 256; + *batch++ = 0; + + return batch; +} + +/* + * 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, + i915_scratch_offset(engine->i915) + + 2 * CACHELINE_BYTES); + + *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(engine->i915, CTX_WA_BB_OBJ_SIZE); + if (IS_ERR(obj)) + return PTR_ERR(obj); + + vma = i915_vma_instance(obj, &engine->i915->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) +{ + struct drm_i915_private *dev_priv = engine->i915; + + intel_engine_set_hwsp_writemask(engine, ~0u); /* HWSTAM */ + + if (INTEL_GEN(dev_priv) >= 11) + I915_WRITE(RING_MODE_GEN7(engine), + _MASKED_BIT_ENABLE(GEN11_GFX_DISABLE_LEGACY_MODE)); + else + I915_WRITE(RING_MODE_GEN7(engine), + _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE)); + + I915_WRITE(RING_MI_MODE(engine->mmio_base), + _MASKED_BIT_DISABLE(STOP_RING)); + + I915_WRITE(RING_HWS_PGA(engine->mmio_base), + i915_ggtt_offset(engine->status_page.vma)); + POSTING_READ(RING_HWS_PGA(engine->mmio_base)); +} + +static bool unexpected_starting_state(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + bool unexpected = false; + + if (I915_READ(RING_MI_MODE(engine->mmio_base)) & 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->timeline.lock, flags); + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static bool lrc_regs_ok(const struct i915_request *rq) +{ + const struct intel_ring *ring = rq->ring; + const u32 *regs = rq->hw_context->lrc_reg_state; + + /* Quick spot check for the common signs of context corruption */ + + if (regs[CTX_RING_BUFFER_CONTROL + 1] != + (RING_CTL_SIZE(ring->size) | RING_VALID)) + return false; + + if (regs[CTX_RING_BUFFER_START + 1] != i915_ggtt_offset(ring->vma)) + return false; + + return true; +} + +static void reset_csb_pointers(struct intel_engine_execlists *execlists) +{ + const unsigned int reset_value = execlists->csb_size - 1; + + /* + * 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->timeline.requests; + const struct intel_context * const context = rq->hw_context; + struct i915_request *active = NULL; + + list_for_each_entry_from_reverse(rq, list, 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->execlists); + + /* + * 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. + */ + if (!port_isset(execlists->port)) + goto out_clear; + + rq = port_request(execlists->port); + ce = rq->hw_context; + + /* + * 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); + + rq = active_request(rq); + if (!rq) + goto out_replay; + + /* + * 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) && lrc_regs_ok(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 && lrc_regs_ok(rq)) + 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: + /* Rerun the request; its payload has been neutered (if guilty). */ + ce->ring->head = + rq ? intel_ring_wrap(ce->ring, rq->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); + +out_clear: + execlists_clear_all_active(execlists); +} + +static void execlists_reset(struct intel_engine_cs *engine, bool stalled) +{ + unsigned long flags; + + GEM_TRACE("%s\n", engine->name); + + spin_lock_irqsave(&engine->timeline.lock, flags); + + __execlists_reset(engine, stalled); + + spin_unlock_irqrestore(&engine->timeline.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->timeline.lock, flags); + + __execlists_reset(engine, true); + + /* Mark all executing requests as skipped. */ + list_for_each_entry(rq, &engine->timeline.requests, 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.timeline.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.timeline.lock); + } + + /* Remaining _unready_ requests will be nop'ed when submitted */ + + execlists->queue_priority_hint = INT_MIN; + execlists->queue = RB_ROOT_CACHED; + GEM_BUG_ON(port_isset(execlists->port)); + + GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet)); + execlists->tasklet.func = nop_submission_tasklet; + + spin_unlock_irqrestore(&engine->timeline.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 = + i915_scratch_offset(engine->i915) + 2 * CACHELINE_BYTES; + 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 *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; + + 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; + + 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 i915_gem_render_state_emit(rq); +} + +static void execlists_park(struct intel_engine_cs *engine) +{ + 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 (engine->preempt_context && + 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); + + 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 drm_i915_private *i915 = engine->i915; + struct intel_engine_execlists * const execlists = &engine->execlists; + u32 base = engine->mmio_base; + int ret; + + ret = intel_engine_init_common(engine); + if (ret) + return ret; + + intel_engine_init_workarounds(engine); + intel_engine_init_whitelist(engine); + + 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 = i915->uncore.regs + + i915_mmio_reg_offset(RING_EXECLIST_SQ_CONTENTS(base)); + execlists->ctrl_reg = i915->uncore.regs + + i915_mmio_reg_offset(RING_EXECLIST_CONTROL(base)); + } else { + execlists->submit_reg = i915->uncore.regs + + i915_mmio_reg_offset(RING_ELSP(base)); + } + + execlists->preempt_complete_status = ~0u; + if (engine->preempt_context) + execlists->preempt_complete_status = + upper_32_bits(engine->preempt_context->lrc_desc); + + 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(engine->i915) < 11) + execlists->csb_size = GEN8_CSB_ENTRIES; + else + execlists->csb_size = GEN11_CSB_ENTRIES; + + reset_csb_pointers(execlists); + + 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_hw_ppgtt *ppgtt = ce->gem_context->ppgtt; + 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); + if (ce->gem_context == engine->i915->preempt_context && + INTEL_GEN(engine->i915) < 11) + regs[CTX_CONTEXT_CONTROL + 1] |= + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_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 i915_timeline *get_timeline(struct i915_gem_context *ctx) +{ + if (ctx->timeline) + return i915_timeline_get(ctx->timeline); + else + return i915_timeline_create(ctx->i915, 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 i915_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(engine->i915, context_size); + if (IS_ERR(ctx_obj)) + return PTR_ERR(ctx_obj); + + vma = i915_vma_instance(ctx_obj, &engine->i915->ggtt.vm, NULL); + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto error_deref_obj; + } + + timeline = get_timeline(ce->gem_context); + if (IS_ERR(timeline)) { + ret = PTR_ERR(timeline); + goto error_deref_obj; + } + + ring = intel_engine_create_ring(engine, + timeline, + ce->gem_context->ring_size); + i915_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 void virtual_context_destroy(struct kref *kref) +{ + struct virtual_engine *ve = + container_of(kref, typeof(*ve), context.ref); + unsigned int n; + + GEM_BUG_ON(ve->request); + GEM_BUG_ON(ve->context.active); + + 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->timeline.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->timeline.lock); + } + GEM_BUG_ON(__tasklet_is_scheduled(&ve->base.execlists.tasklet)); + + if (ve->context.state) + __execlists_context_fini(&ve->context); + + kfree(ve->bonds); + + i915_timeline_fini(&ve->base.timeline); + 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; + + ce->saturated = 0; + 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->timeline.lock); + rb_erase_cached(&node->rb, + &sibling->execlists.virtual); + RB_CLEAR_NODE(&node->rb); + spin_unlock(&sibling->timeline.lock); + } + continue; + } + + spin_lock(&sibling->timeline.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->timeline.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); + ve->base.execlists.queue_priority_hint = rq_prio(rq); + WRITE_ONCE(ve->request, rq); + + 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.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; + + snprintf(ve->base.name, sizeof(ve->base.name), "virtual"); + + err = i915_timeline_init(ctx->i915, &ve->base.timeline, NULL); + if (err) + goto err_put; + i915_timeline_set_subclass(&ve->base.timeline, TIMELINE_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; + + 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->timeline.lock, flags); + + last = NULL; + count = 0; + list_for_each_entry(rq, &engine->timeline.requests, 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->timeline.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 |