From c2776afe740db5598c4c457dcacb94d4427b13f9 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Christian=20K=C3=B6nig?= Date: Tue, 3 Nov 2015 13:27:39 +0100 Subject: [PATCH] drm/amdgpu: use a timer for fence fallback MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Less overhead than a work item and also adds proper cleanup handling. Signed-off-by: Christian König Reviewed-by: Chunming Zhou Acked-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 78 ++++++++++------------- 2 files changed, 35 insertions(+), 46 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 615ce6d464fb..3630cb545d0d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -389,7 +389,6 @@ struct amdgpu_clock { * Fences. */ struct amdgpu_fence_driver { - struct amdgpu_ring *ring; uint64_t gpu_addr; volatile uint32_t *cpu_addr; /* sync_seq is protected by ring emission lock */ @@ -398,7 +397,7 @@ struct amdgpu_fence_driver { bool initialized; struct amdgpu_irq_src *irq_src; unsigned irq_type; - struct delayed_work lockup_work; + struct timer_list fallback_timer; wait_queue_head_t fence_queue; }; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index b92c1937543a..257fce356319 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -84,24 +84,6 @@ static u32 amdgpu_fence_read(struct amdgpu_ring *ring) return seq; } -/** - * amdgpu_fence_schedule_check - schedule lockup check - * - * @ring: pointer to struct amdgpu_ring - * - * Queues a delayed work item to check for lockups. - */ -static void amdgpu_fence_schedule_check(struct amdgpu_ring *ring) -{ - /* - * Do not reset the timer here with mod_delayed_work, - * this can livelock in an interaction with TTM delayed destroy. - */ - queue_delayed_work(system_power_efficient_wq, - &ring->fence_drv.lockup_work, - AMDGPU_FENCE_JIFFIES_TIMEOUT); -} - /** * amdgpu_fence_emit - emit a fence on the requested ring * @@ -135,6 +117,19 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, void *owner, return 0; } +/** + * amdgpu_fence_schedule_fallback - schedule fallback check + * + * @ring: pointer to struct amdgpu_ring + * + * Start a timer as fallback to our interrupts. + */ +static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring) +{ + mod_timer(&ring->fence_drv.fallback_timer, + jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT); +} + /** * amdgpu_fence_activity - check for fence activity * @@ -201,45 +196,38 @@ static bool amdgpu_fence_activity(struct amdgpu_ring *ring) } while (atomic64_xchg(&ring->fence_drv.last_seq, seq) > seq); if (seq < last_emitted) - amdgpu_fence_schedule_check(ring); + amdgpu_fence_schedule_fallback(ring); return wake; } /** - * amdgpu_fence_check_lockup - check for hardware lockup + * amdgpu_fence_process - process a fence * - * @work: delayed work item + * @adev: amdgpu_device pointer + * @ring: ring index the fence is associated with * - * Checks for fence activity and if there is none probe - * the hardware if a lockup occured. + * Checks the current fence value and wakes the fence queue + * if the sequence number has increased (all asics). */ -static void amdgpu_fence_check_lockup(struct work_struct *work) +void amdgpu_fence_process(struct amdgpu_ring *ring) { - struct amdgpu_fence_driver *fence_drv; - struct amdgpu_ring *ring; - - fence_drv = container_of(work, struct amdgpu_fence_driver, - lockup_work.work); - ring = fence_drv->ring; - if (amdgpu_fence_activity(ring)) wake_up_all(&ring->fence_drv.fence_queue); } /** - * amdgpu_fence_process - process a fence + * amdgpu_fence_fallback - fallback for hardware interrupts * - * @adev: amdgpu_device pointer - * @ring: ring index the fence is associated with + * @work: delayed work item * - * Checks the current fence value and wakes the fence queue - * if the sequence number has increased (all asics). + * Checks for fence activity. */ -void amdgpu_fence_process(struct amdgpu_ring *ring) +static void amdgpu_fence_fallback(unsigned long arg) { - if (amdgpu_fence_activity(ring)) - wake_up_all(&ring->fence_drv.fence_queue); + struct amdgpu_ring *ring = (void *)arg; + + amdgpu_fence_process(ring); } /** @@ -289,7 +277,7 @@ static int amdgpu_fence_ring_wait_seq(struct amdgpu_ring *ring, uint64_t seq) if (atomic64_read(&ring->fence_drv.last_seq) >= seq) return 0; - amdgpu_fence_schedule_check(ring); + amdgpu_fence_schedule_fallback(ring); wait_event(ring->fence_drv.fence_queue, ( (signaled = amdgpu_fence_seq_signaled(ring, seq)))); @@ -490,9 +478,8 @@ int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring) atomic64_set(&ring->fence_drv.last_seq, 0); ring->fence_drv.initialized = false; - INIT_DELAYED_WORK(&ring->fence_drv.lockup_work, - amdgpu_fence_check_lockup); - ring->fence_drv.ring = ring; + setup_timer(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback, + (unsigned long)ring); init_waitqueue_head(&ring->fence_drv.fence_queue); @@ -556,6 +543,7 @@ void amdgpu_fence_driver_fini(struct amdgpu_device *adev) mutex_lock(&adev->ring_lock); for (i = 0; i < AMDGPU_MAX_RINGS; i++) { struct amdgpu_ring *ring = adev->rings[i]; + if (!ring || !ring->fence_drv.initialized) continue; r = amdgpu_fence_wait_empty(ring); @@ -567,6 +555,7 @@ void amdgpu_fence_driver_fini(struct amdgpu_device *adev) amdgpu_irq_put(adev, ring->fence_drv.irq_src, ring->fence_drv.irq_type); amd_sched_fini(&ring->sched); + del_timer_sync(&ring->fence_drv.fallback_timer); ring->fence_drv.initialized = false; } mutex_unlock(&adev->ring_lock); @@ -750,7 +739,8 @@ static bool amdgpu_fence_enable_signaling(struct fence *f) fence->fence_wake.func = amdgpu_fence_check_signaled; __add_wait_queue(&ring->fence_drv.fence_queue, &fence->fence_wake); fence_get(f); - amdgpu_fence_schedule_check(ring); + if (!timer_pending(&ring->fence_drv.fallback_timer)) + amdgpu_fence_schedule_fallback(ring); FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx); return true; } -- 2.39.2