diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_request.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_request.c | 138 |
1 files changed, 136 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index d354967d6ae8..59e30b8c4ee9 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -22,8 +22,9 @@ * */ -#include <linux/prefetch.h> #include <linux/dma-fence-array.h> +#include <linux/irq_work.h> +#include <linux/prefetch.h> #include <linux/sched.h> #include <linux/sched/clock.h> #include <linux/sched/signal.h> @@ -32,9 +33,16 @@ #include "i915_active.h" #include "i915_reset.h" +struct execute_cb { + struct list_head link; + struct irq_work work; + struct i915_sw_fence *fence; +}; + static struct i915_global_request { struct kmem_cache *slab_requests; struct kmem_cache *slab_dependencies; + struct kmem_cache *slab_execute_cbs; } global; static const char *i915_fence_get_driver_name(struct dma_fence *fence) @@ -325,6 +333,69 @@ void i915_request_retire_upto(struct i915_request *rq) } while (tmp != rq); } +static void irq_execute_cb(struct irq_work *wrk) +{ + struct execute_cb *cb = container_of(wrk, typeof(*cb), work); + + i915_sw_fence_complete(cb->fence); + kmem_cache_free(global.slab_execute_cbs, cb); +} + +static void __notify_execute_cb(struct i915_request *rq) +{ + struct execute_cb *cb; + + lockdep_assert_held(&rq->lock); + + if (list_empty(&rq->execute_cb)) + return; + + list_for_each_entry(cb, &rq->execute_cb, link) + irq_work_queue(&cb->work); + + /* + * XXX Rollback on __i915_request_unsubmit() + * + * In the future, perhaps when we have an active time-slicing scheduler, + * it will be interesting to unsubmit parallel execution and remove + * busywaits from the GPU until their master is restarted. This is + * quite hairy, we have to carefully rollback the fence and do a + * preempt-to-idle cycle on the target engine, all the while the + * master execute_cb may refire. + */ + INIT_LIST_HEAD(&rq->execute_cb); +} + +static int +i915_request_await_execution(struct i915_request *rq, + struct i915_request *signal, + gfp_t gfp) +{ + struct execute_cb *cb; + + if (i915_request_is_active(signal)) + return 0; + + cb = kmem_cache_alloc(global.slab_execute_cbs, gfp); + if (!cb) + return -ENOMEM; + + cb->fence = &rq->submit; + i915_sw_fence_await(cb->fence); + init_irq_work(&cb->work, irq_execute_cb); + + spin_lock_irq(&signal->lock); + if (i915_request_is_active(signal)) { + i915_sw_fence_complete(cb->fence); + kmem_cache_free(global.slab_execute_cbs, cb); + } else { + list_add_tail(&cb->link, &signal->execute_cb); + } + spin_unlock_irq(&signal->lock); + + return 0; +} + static void move_to_timeline(struct i915_request *request, struct i915_timeline *timeline) { @@ -361,6 +432,8 @@ void __i915_request_submit(struct i915_request *request) !i915_request_enable_breadcrumb(request)) intel_engine_queue_breadcrumbs(engine); + __notify_execute_cb(request); + spin_unlock(&request->lock); engine->emit_fini_breadcrumb(request, @@ -608,6 +681,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx) } INIT_LIST_HEAD(&rq->active_list); + INIT_LIST_HEAD(&rq->execute_cb); tl = ce->ring->timeline; ret = i915_timeline_get_seqno(tl, rq, &seqno); @@ -697,6 +771,52 @@ err_unreserve: } static int +emit_semaphore_wait(struct i915_request *to, + struct i915_request *from, + gfp_t gfp) +{ + u32 hwsp_offset; + u32 *cs; + int err; + + GEM_BUG_ON(!from->timeline->has_initial_breadcrumb); + GEM_BUG_ON(INTEL_GEN(to->i915) < 8); + + /* We need to pin the signaler's HWSP until we are finished reading. */ + err = i915_timeline_read_hwsp(from, to, &hwsp_offset); + if (err) + return err; + + /* Only submit our spinner after the signaler is running! */ + err = i915_request_await_execution(to, from, gfp); + if (err) + return err; + + cs = intel_ring_begin(to, 4); + if (IS_ERR(cs)) + return PTR_ERR(cs); + + /* + * Using greater-than-or-equal here means we have to worry + * about seqno wraparound. To side step that issue, we swap + * the timeline HWSP upon wrapping, so that everyone listening + * for the old (pre-wrap) values do not see the much smaller + * (post-wrap) values than they were expecting (and so wait + * forever). + */ + *cs++ = MI_SEMAPHORE_WAIT | + MI_SEMAPHORE_GLOBAL_GTT | + MI_SEMAPHORE_POLL | + MI_SEMAPHORE_SAD_GTE_SDD; + *cs++ = from->fence.seqno; + *cs++ = hwsp_offset; + *cs++ = 0; + + intel_ring_advance(to, cs); + return 0; +} + +static int i915_request_await_request(struct i915_request *to, struct i915_request *from) { int ret; @@ -717,6 +837,9 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, I915_FENCE_GFP); + } else if (intel_engine_has_semaphores(to->engine) && + to->gem_context->sched.priority >= I915_PRIORITY_NORMAL) { + ret = emit_semaphore_wait(to, from, I915_FENCE_GFP); } else { ret = i915_sw_fence_await_dma_fence(&to->submit, &from->fence, 0, @@ -1208,14 +1331,23 @@ int __init i915_global_request_init(void) if (!global.slab_requests) return -ENOMEM; + global.slab_execute_cbs = KMEM_CACHE(execute_cb, + SLAB_HWCACHE_ALIGN | + SLAB_RECLAIM_ACCOUNT | + SLAB_TYPESAFE_BY_RCU); + if (!global.slab_execute_cbs) + goto err_requests; + global.slab_dependencies = KMEM_CACHE(i915_dependency, SLAB_HWCACHE_ALIGN | SLAB_RECLAIM_ACCOUNT); if (!global.slab_dependencies) - goto err_requests; + goto err_execute_cbs; return 0; +err_execute_cbs: + kmem_cache_destroy(global.slab_execute_cbs); err_requests: kmem_cache_destroy(global.slab_requests); return -ENOMEM; @@ -1224,11 +1356,13 @@ err_requests: void i915_global_request_shrink(void) { kmem_cache_shrink(global.slab_dependencies); + kmem_cache_shrink(global.slab_execute_cbs); kmem_cache_shrink(global.slab_requests); } void i915_global_request_exit(void) { kmem_cache_destroy(global.slab_dependencies); + kmem_cache_destroy(global.slab_execute_cbs); kmem_cache_destroy(global.slab_requests); } |