diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 682 |
1 files changed, 682 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c new file mode 100644 index 000000000000..9e42324fdecd --- /dev/null +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -0,0 +1,682 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2014 Intel Corporation + */ + +#include <linux/circ_buf.h> + +#include "gem/i915_gem_context.h" +#include "gt/intel_context.h" +#include "gt/intel_engine_pm.h" +#include "gt/intel_gt.h" +#include "gt/intel_gt_pm.h" +#include "gt/intel_lrc_reg.h" +#include "gt/intel_ring.h" + +#include "intel_guc_submission.h" + +#include "i915_drv.h" +#include "i915_trace.h" + +/** + * DOC: GuC-based command submission + * + * IMPORTANT NOTE: GuC submission is currently not supported in i915. The GuC + * firmware is moving to an updated submission interface and we plan to + * turn submission back on when that lands. The below documentation (and related + * code) matches the old submission model and will be updated as part of the + * upgrade to the new flow. + * + * GuC stage descriptor: + * During initialization, the driver allocates a static pool of 1024 such + * descriptors, and shares them with the GuC. Currently, we only use one + * descriptor. This stage descriptor lets the GuC know about the workqueue and + * process descriptor. Theoretically, it also lets the GuC know about our HW + * contexts (context ID, etc...), but we actually employ a kind of submission + * where the GuC uses the LRCA sent via the work item instead. This is called + * a "proxy" submission. + * + * The Scratch registers: + * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes + * a value to the action register (SOFT_SCRATCH_0) along with any data. It then + * triggers an interrupt on the GuC via another register write (0xC4C8). + * Firmware writes a success/fail code back to the action register after + * processes the request. The kernel driver polls waiting for this update and + * then proceeds. + * + * Work Items: + * There are several types of work items that the host may place into a + * workqueue, each with its own requirements and limitations. Currently only + * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which + * represents in-order queue. The kernel driver packs ring tail pointer and an + * ELSP context descriptor dword into Work Item. + * See guc_add_request() + * + */ + +static inline struct i915_priolist *to_priolist(struct rb_node *rb) +{ + return rb_entry(rb, struct i915_priolist, node); +} + +static struct guc_stage_desc *__get_stage_desc(struct intel_guc *guc, u32 id) +{ + struct guc_stage_desc *base = guc->stage_desc_pool_vaddr; + + return &base[id]; +} + +static int guc_workqueue_create(struct intel_guc *guc) +{ + return intel_guc_allocate_and_map_vma(guc, GUC_WQ_SIZE, &guc->workqueue, + &guc->workqueue_vaddr); +} + +static void guc_workqueue_destroy(struct intel_guc *guc) +{ + i915_vma_unpin_and_release(&guc->workqueue, I915_VMA_RELEASE_MAP); +} + +/* + * Initialise the process descriptor shared with the GuC firmware. + */ +static int guc_proc_desc_create(struct intel_guc *guc) +{ + const u32 size = PAGE_ALIGN(sizeof(struct guc_process_desc)); + + return intel_guc_allocate_and_map_vma(guc, size, &guc->proc_desc, + &guc->proc_desc_vaddr); +} + +static void guc_proc_desc_destroy(struct intel_guc *guc) +{ + i915_vma_unpin_and_release(&guc->proc_desc, I915_VMA_RELEASE_MAP); +} + +static void guc_proc_desc_init(struct intel_guc *guc) +{ + struct guc_process_desc *desc; + + desc = memset(guc->proc_desc_vaddr, 0, sizeof(*desc)); + + /* + * XXX: pDoorbell and WQVBaseAddress are pointers in process address + * space for ring3 clients (set them as in mmap_ioctl) or kernel + * space for kernel clients (map on demand instead? May make debug + * easier to have it mapped). + */ + desc->wq_base_addr = 0; + desc->db_base_addr = 0; + + desc->wq_size_bytes = GUC_WQ_SIZE; + desc->wq_status = WQ_STATUS_ACTIVE; + desc->priority = GUC_CLIENT_PRIORITY_KMD_NORMAL; +} + +static void guc_proc_desc_fini(struct intel_guc *guc) +{ + memset(guc->proc_desc_vaddr, 0, sizeof(struct guc_process_desc)); +} + +static int guc_stage_desc_pool_create(struct intel_guc *guc) +{ + u32 size = PAGE_ALIGN(sizeof(struct guc_stage_desc) * + GUC_MAX_STAGE_DESCRIPTORS); + + return intel_guc_allocate_and_map_vma(guc, size, &guc->stage_desc_pool, + &guc->stage_desc_pool_vaddr); +} + +static void guc_stage_desc_pool_destroy(struct intel_guc *guc) +{ + i915_vma_unpin_and_release(&guc->stage_desc_pool, I915_VMA_RELEASE_MAP); +} + +/* + * Initialise/clear the stage descriptor shared with the GuC firmware. + * + * This descriptor tells the GuC where (in GGTT space) to find the important + * data structures related to work submission (process descriptor, write queue, + * etc). + */ +static void guc_stage_desc_init(struct intel_guc *guc) +{ + struct guc_stage_desc *desc; + + /* we only use 1 stage desc, so hardcode it to 0 */ + desc = __get_stage_desc(guc, 0); + memset(desc, 0, sizeof(*desc)); + + desc->attribute = GUC_STAGE_DESC_ATTR_ACTIVE | + GUC_STAGE_DESC_ATTR_KERNEL; + + desc->stage_id = 0; + desc->priority = GUC_CLIENT_PRIORITY_KMD_NORMAL; + + desc->process_desc = intel_guc_ggtt_offset(guc, guc->proc_desc); + desc->wq_addr = intel_guc_ggtt_offset(guc, guc->workqueue); + desc->wq_size = GUC_WQ_SIZE; +} + +static void guc_stage_desc_fini(struct intel_guc *guc) +{ + struct guc_stage_desc *desc; + + desc = __get_stage_desc(guc, 0); + memset(desc, 0, sizeof(*desc)); +} + +/* Construct a Work Item and append it to the GuC's Work Queue */ +static void guc_wq_item_append(struct intel_guc *guc, + u32 target_engine, u32 context_desc, + u32 ring_tail, u32 fence_id) +{ + /* wqi_len is in DWords, and does not include the one-word header */ + const size_t wqi_size = sizeof(struct guc_wq_item); + const u32 wqi_len = wqi_size / sizeof(u32) - 1; + struct guc_process_desc *desc = guc->proc_desc_vaddr; + struct guc_wq_item *wqi; + u32 wq_off; + + lockdep_assert_held(&guc->wq_lock); + + /* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we + * should not have the case where structure wqi is across page, neither + * wrapped to the beginning. This simplifies the implementation below. + * + * XXX: if not the case, we need save data to a temp wqi and copy it to + * workqueue buffer dw by dw. + */ + BUILD_BUG_ON(wqi_size != 16); + + /* We expect the WQ to be active if we're appending items to it */ + GEM_BUG_ON(desc->wq_status != WQ_STATUS_ACTIVE); + + /* Free space is guaranteed. */ + wq_off = READ_ONCE(desc->tail); + GEM_BUG_ON(CIRC_SPACE(wq_off, READ_ONCE(desc->head), + GUC_WQ_SIZE) < wqi_size); + GEM_BUG_ON(wq_off & (wqi_size - 1)); + + wqi = guc->workqueue_vaddr + wq_off; + + /* Now fill in the 4-word work queue item */ + wqi->header = WQ_TYPE_INORDER | + (wqi_len << WQ_LEN_SHIFT) | + (target_engine << WQ_TARGET_SHIFT) | + WQ_NO_WCFLUSH_WAIT; + wqi->context_desc = context_desc; + wqi->submit_element_info = ring_tail << WQ_RING_TAIL_SHIFT; + GEM_BUG_ON(ring_tail > WQ_RING_TAIL_MAX); + wqi->fence_id = fence_id; + + /* Make the update visible to GuC */ + WRITE_ONCE(desc->tail, (wq_off + wqi_size) & (GUC_WQ_SIZE - 1)); +} + +static void guc_add_request(struct intel_guc *guc, struct i915_request *rq) +{ + struct intel_engine_cs *engine = rq->engine; + u32 ctx_desc = lower_32_bits(rq->context->lrc_desc); + u32 ring_tail = intel_ring_set_tail(rq->ring, rq->tail) / sizeof(u64); + + guc_wq_item_append(guc, engine->guc_id, ctx_desc, + ring_tail, rq->fence.seqno); +} + +/* + * When we're doing submissions using regular execlists backend, writing to + * ELSP from CPU side is enough to make sure that writes to ringbuffer pages + * pinned in mappable aperture portion of GGTT are visible to command streamer. + * Writes done by GuC on our behalf are not guaranteeing such ordering, + * therefore, to ensure the flush, we're issuing a POSTING READ. + */ +static void flush_ggtt_writes(struct i915_vma *vma) +{ + if (i915_vma_is_map_and_fenceable(vma)) + intel_uncore_posting_read_fw(vma->vm->gt->uncore, + GUC_STATUS); +} + +static void guc_submit(struct intel_engine_cs *engine, + struct i915_request **out, + struct i915_request **end) +{ + struct intel_guc *guc = &engine->gt->uc.guc; + + spin_lock(&guc->wq_lock); + + do { + struct i915_request *rq = *out++; + + flush_ggtt_writes(rq->ring->vma); + guc_add_request(guc, rq); + } while (out != end); + + spin_unlock(&guc->wq_lock); +} + +static inline int rq_prio(const struct i915_request *rq) +{ + return rq->sched.attr.priority | __NO_PREEMPTION; +} + +static struct i915_request *schedule_in(struct i915_request *rq, int idx) +{ + trace_i915_request_in(rq, idx); + + /* + * Currently we are not tracking the rq->context being inflight + * (ce->inflight = rq->engine). It is only used by the execlists + * backend at the moment, a similar counting strategy would be + * required if we generalise the inflight tracking. + */ + + __intel_gt_pm_get(rq->engine->gt); + return i915_request_get(rq); +} + +static void schedule_out(struct i915_request *rq) +{ + trace_i915_request_out(rq); + + intel_gt_pm_put_async(rq->engine->gt); + i915_request_put(rq); +} + +static void __guc_dequeue(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct i915_request **first = execlists->inflight; + struct i915_request ** const last_port = first + execlists->port_mask; + struct i915_request *last = first[0]; + struct i915_request **port; + bool submit = false; + struct rb_node *rb; + + lockdep_assert_held(&engine->active.lock); + + if (last) { + if (*++first) + return; + + last = NULL; + } + + /* + * We write directly into the execlists->inflight queue and don't use + * the execlists->pending queue, as we don't have a distinct switch + * event. + */ + port = first; + while ((rb = rb_first_cached(&execlists->queue))) { + struct i915_priolist *p = to_priolist(rb); + struct i915_request *rq, *rn; + int i; + + priolist_for_each_request_consume(rq, rn, p, i) { + if (last && rq->context != last->context) { + if (port == last_port) + goto done; + + *port = schedule_in(last, + port - execlists->inflight); + port++; + } + + list_del_init(&rq->sched.link); + __i915_request_submit(rq); + submit = true; + last = rq; + } + + rb_erase_cached(&p->node, &execlists->queue); + i915_priolist_free(p); + } +done: + execlists->queue_priority_hint = + rb ? to_priolist(rb)->priority : INT_MIN; + if (submit) { + *port = schedule_in(last, port - execlists->inflight); + *++port = NULL; + guc_submit(engine, first, port); + } + execlists->active = execlists->inflight; +} + +static void guc_submission_tasklet(unsigned long data) +{ + struct intel_engine_cs * const engine = (struct intel_engine_cs *)data; + struct intel_engine_execlists * const execlists = &engine->execlists; + struct i915_request **port, *rq; + unsigned long flags; + + spin_lock_irqsave(&engine->active.lock, flags); + + for (port = execlists->inflight; (rq = *port); port++) { + if (!i915_request_completed(rq)) + break; + + schedule_out(rq); + } + if (port != execlists->inflight) { + int idx = port - execlists->inflight; + int rem = ARRAY_SIZE(execlists->inflight) - idx; + memmove(execlists->inflight, port, rem * sizeof(*port)); + } + + __guc_dequeue(engine); + + spin_unlock_irqrestore(&engine->active.lock, flags); +} + +static void guc_reset_prepare(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + + ENGINE_TRACE(engine, "\n"); + + /* + * 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->init_hw() and also writing the ELSP. + * Turning off the execlists->tasklet until the reset is over + * prevents the race. + */ + __tasklet_disable_sync_once(&execlists->tasklet); +} + +static void +cancel_port_requests(struct intel_engine_execlists * const execlists) +{ + struct i915_request * const *port, *rq; + + /* Note we are only using the inflight and not the pending queue */ + + for (port = execlists->active; (rq = *port); port++) + schedule_out(rq); + execlists->active = + memset(execlists->inflight, 0, sizeof(execlists->inflight)); +} + +static void guc_reset_rewind(struct intel_engine_cs *engine, bool stalled) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct i915_request *rq; + unsigned long flags; + + spin_lock_irqsave(&engine->active.lock, flags); + + cancel_port_requests(execlists); + + /* Push back any incomplete requests for replay after the reset. */ + rq = execlists_unwind_incomplete_requests(execlists); + if (!rq) + goto out_unlock; + + if (!i915_request_started(rq)) + stalled = false; + + __i915_request_reset(rq, stalled); + intel_lr_context_reset(engine, rq->context, rq->head, stalled); + +out_unlock: + spin_unlock_irqrestore(&engine->active.lock, flags); +} + +static void guc_reset_cancel(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; + + ENGINE_TRACE(engine, "\n"); + + /* + * Before we call engine->cancel_requests(), we should have exclusive + * access to the submission state. This is arranged for us by the + * caller disabling the interrupt generation, the tasklet and other + * threads that may then access the same state, giving us a free hand + * to reset state. However, we still need to let lockdep be aware that + * we know this state may be accessed in hardirq context, so we + * disable the irq around this manipulation and we want to keep + * the spinlock focused on its duties and not accidentally conflate + * coverage to the submission's irq state. (Similarly, although we + * shouldn't need to disable irq around the manipulation of the + * submission's irq state, we also wish to remind ourselves that + * it is irq state.) + */ + spin_lock_irqsave(&engine->active.lock, flags); + + /* Cancel the requests on the HW and clear the ELSP tracker. */ + cancel_port_requests(execlists); + + /* Mark all executing requests as skipped. */ + list_for_each_entry(rq, &engine->active.requests, sched.link) { + if (!i915_request_signaled(rq)) + dma_fence_set_error(&rq->fence, -EIO); + + i915_request_mark_complete(rq); + } + + /* Flush the queued requests to the timeline list (for retiring). */ + while ((rb = rb_first_cached(&execlists->queue))) { + struct i915_priolist *p = to_priolist(rb); + int i; + + priolist_for_each_request_consume(rq, rn, p, i) { + list_del_init(&rq->sched.link); + __i915_request_submit(rq); + dma_fence_set_error(&rq->fence, -EIO); + i915_request_mark_complete(rq); + } + + rb_erase_cached(&p->node, &execlists->queue); + i915_priolist_free(p); + } + + /* Remaining _unready_ requests will be nop'ed when submitted */ + + execlists->queue_priority_hint = INT_MIN; + execlists->queue = RB_ROOT_CACHED; + + spin_unlock_irqrestore(&engine->active.lock, flags); +} + +static void guc_reset_finish(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + + if (__tasklet_enable(&execlists->tasklet)) + /* And kick in case we missed a new request submission. */ + tasklet_hi_schedule(&execlists->tasklet); + + ENGINE_TRACE(engine, "depth->%d\n", + atomic_read(&execlists->tasklet.count)); +} + +/* + * Everything below here is concerned with setup & teardown, and is + * therefore not part of the somewhat time-critical batch-submission + * path of guc_submit() above. + */ + +/* + * Set up the memory resources to be shared with the GuC (via the GGTT) + * at firmware loading time. + */ +int intel_guc_submission_init(struct intel_guc *guc) +{ + int ret; + + if (guc->stage_desc_pool) + return 0; + + ret = guc_stage_desc_pool_create(guc); + if (ret) + return ret; + /* + * Keep static analysers happy, let them know that we allocated the + * vma after testing that it didn't exist earlier. + */ + GEM_BUG_ON(!guc->stage_desc_pool); + + ret = guc_workqueue_create(guc); + if (ret) + goto err_pool; + + ret = guc_proc_desc_create(guc); + if (ret) + goto err_workqueue; + + spin_lock_init(&guc->wq_lock); + + return 0; + +err_workqueue: + guc_workqueue_destroy(guc); +err_pool: + guc_stage_desc_pool_destroy(guc); + return ret; +} + +void intel_guc_submission_fini(struct intel_guc *guc) +{ + if (guc->stage_desc_pool) { + guc_proc_desc_destroy(guc); + guc_workqueue_destroy(guc); + guc_stage_desc_pool_destroy(guc); + } +} + +static void guc_interrupts_capture(struct intel_gt *gt) +{ + struct intel_uncore *uncore = gt->uncore; + u32 irqs = GT_CONTEXT_SWITCH_INTERRUPT; + u32 dmask = irqs << 16 | irqs; + + GEM_BUG_ON(INTEL_GEN(gt->i915) < 11); + + /* Don't handle the ctx switch interrupt in GuC submission mode */ + intel_uncore_rmw(uncore, GEN11_RENDER_COPY_INTR_ENABLE, dmask, 0); + intel_uncore_rmw(uncore, GEN11_VCS_VECS_INTR_ENABLE, dmask, 0); +} + +static void guc_interrupts_release(struct intel_gt *gt) +{ + struct intel_uncore *uncore = gt->uncore; + u32 irqs = GT_CONTEXT_SWITCH_INTERRUPT; + u32 dmask = irqs << 16 | irqs; + + GEM_BUG_ON(INTEL_GEN(gt->i915) < 11); + + /* Handle ctx switch interrupts again */ + intel_uncore_rmw(uncore, GEN11_RENDER_COPY_INTR_ENABLE, 0, dmask); + intel_uncore_rmw(uncore, GEN11_VCS_VECS_INTR_ENABLE, 0, dmask); +} + +static void guc_set_default_submission(struct intel_engine_cs *engine) +{ + /* + * We inherit a bunch of functions from execlists that we'd like + * to keep using: + * + * engine->submit_request = execlists_submit_request; + * engine->cancel_requests = execlists_cancel_requests; + * engine->schedule = execlists_schedule; + * + * But we need to override the actual submission backend in order + * to talk to the GuC. + */ + intel_execlists_set_default_submission(engine); + + engine->execlists.tasklet.func = guc_submission_tasklet; + + /* do not use execlists park/unpark */ + engine->park = engine->unpark = NULL; + + engine->reset.prepare = guc_reset_prepare; + engine->reset.rewind = guc_reset_rewind; + engine->reset.cancel = guc_reset_cancel; + engine->reset.finish = guc_reset_finish; + + engine->flags &= ~I915_ENGINE_SUPPORTS_STATS; + engine->flags |= I915_ENGINE_NEEDS_BREADCRUMB_TASKLET; + + /* + * For the breadcrumb irq to work we need the interrupts to stay + * enabled. However, on all platforms on which we'll have support for + * GuC submission we don't allow disabling the interrupts at runtime, so + * we're always safe with the current flow. + */ + GEM_BUG_ON(engine->irq_enable || engine->irq_disable); +} + +void intel_guc_submission_enable(struct intel_guc *guc) +{ + struct intel_gt *gt = guc_to_gt(guc); + struct intel_engine_cs *engine; + enum intel_engine_id id; + + /* + * We're using GuC work items for submitting work through GuC. Since + * we're coalescing multiple requests from a single context into a + * single work item prior to assigning it to execlist_port, we can + * never have more work items than the total number of ports (for all + * engines). The GuC firmware is controlling the HEAD of work queue, + * and it is guaranteed that it will remove the work item from the + * queue before our request is completed. + */ + BUILD_BUG_ON(ARRAY_SIZE(engine->execlists.inflight) * + sizeof(struct guc_wq_item) * + I915_NUM_ENGINES > GUC_WQ_SIZE); + + guc_proc_desc_init(guc); + guc_stage_desc_init(guc); + + /* Take over from manual control of ELSP (execlists) */ + guc_interrupts_capture(gt); + + for_each_engine(engine, gt, id) { + engine->set_default_submission = guc_set_default_submission; + engine->set_default_submission(engine); + } +} + +void intel_guc_submission_disable(struct intel_guc *guc) +{ + struct intel_gt *gt = guc_to_gt(guc); + + GEM_BUG_ON(gt->awake); /* GT should be parked first */ + + /* Note: By the time we're here, GuC may have already been reset */ + + guc_interrupts_release(gt); + + guc_stage_desc_fini(guc); + guc_proc_desc_fini(guc); +} + +static bool __guc_submission_support(struct intel_guc *guc) +{ + /* XXX: GuC submission is unavailable for now */ + return false; + + if (!intel_guc_is_supported(guc)) + return false; + + return i915_modparams.enable_guc & ENABLE_GUC_SUBMISSION; +} + +void intel_guc_submission_init_early(struct intel_guc *guc) +{ + guc->submission_supported = __guc_submission_support(guc); +} + +bool intel_engine_in_guc_submission_mode(const struct intel_engine_cs *engine) +{ + return engine->set_default_submission == guc_set_default_submission; +} |
