From: Alex Deucher Date: Wed, 28 May 2025 01:35:00 +0000 (-0400) Subject: drm/amdgpu: track ring state associated with a fence X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=77cc0da39c7ce203cd3ce6bc5696421947a979d7;p=thirdparty%2Fkernel%2Flinux.git drm/amdgpu: track ring state associated with a fence We need to know the wptr and sequence number associated with a fence so that we can re-emit the unprocessed state after a ring reset. Pre-allocate storage space for the ring buffer contents and add helpers to save off and re-emit the unprocessed state so that it can be re-emitted after the queue is reset. Reviewed-by: Christian König Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 2c3547f4cea42..9e7506965cab2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -120,6 +120,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, am_fence = kzalloc(sizeof(*am_fence), GFP_KERNEL); if (!am_fence) return -ENOMEM; + am_fence->context = 0; } else { am_fence = af; } @@ -127,6 +128,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, am_fence->ring = ring; seq = ++ring->fence_drv.sync_seq; + am_fence->seq = seq; if (af) { dma_fence_init(fence, &amdgpu_job_fence_ops, &ring->fence_drv.lock, @@ -141,6 +143,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr, seq, flags | AMDGPU_FENCE_FLAG_INT); + amdgpu_fence_save_wptr(fence); pm_runtime_get_noresume(adev_to_drm(adev)->dev); ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask]; if (unlikely(rcu_dereference_protected(*ptr, 1))) { @@ -253,6 +256,7 @@ bool amdgpu_fence_process(struct amdgpu_ring *ring) do { struct dma_fence *fence, **ptr; + struct amdgpu_fence *am_fence; ++last_seq; last_seq &= drv->num_fences_mask; @@ -265,6 +269,12 @@ bool amdgpu_fence_process(struct amdgpu_ring *ring) if (!fence) continue; + /* Save the wptr in the fence driver so we know what the last processed + * wptr was. This is required for re-emitting the ring state for + * queues that are reset but are not guilty and thus have no guilty fence. + */ + am_fence = container_of(fence, struct amdgpu_fence, base); + drv->signalled_wptr = am_fence->wptr; dma_fence_signal(fence); dma_fence_put(fence); pm_runtime_mark_last_busy(adev_to_drm(adev)->dev); @@ -727,6 +737,86 @@ void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring) amdgpu_fence_process(ring); } + +/** + * Kernel queue reset handling + * + * The driver can reset individual queues for most engines, but those queues + * may contain work from multiple contexts. Resetting the queue will reset + * lose all of that state. In order to minimize the collateral damage, the + * driver will save the ring contents which are not associated with the guilty + * context prior to resetting the queue. After resetting the queue the queue + * contents from the other contexts is re-emitted to the rings so that it can + * be processed by the engine. To handle this, we save the queue's write + * pointer (wptr) in the fences associated with each context. If we get a + * queue timeout, we can then use the wptrs from the fences to determine + * which data needs to be saved out of the queue's ring buffer. + */ + +/** + * amdgpu_fence_driver_guilty_force_completion - force signal of specified sequence + * + * @fence: fence of the ring to signal + * + */ +void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *fence) +{ + dma_fence_set_error(&fence->base, -ETIME); + amdgpu_fence_write(fence->ring, fence->seq); + amdgpu_fence_process(fence->ring); +} + +void amdgpu_fence_save_wptr(struct dma_fence *fence) +{ + struct amdgpu_fence *am_fence = container_of(fence, struct amdgpu_fence, base); + + am_fence->wptr = am_fence->ring->wptr; +} + +static void amdgpu_ring_backup_unprocessed_command(struct amdgpu_ring *ring, + u64 start_wptr, u32 end_wptr) +{ + unsigned int first_idx = start_wptr & ring->buf_mask; + unsigned int last_idx = end_wptr & ring->buf_mask; + unsigned int i; + + /* Backup the contents of the ring buffer. */ + for (i = first_idx; i != last_idx; ++i, i &= ring->buf_mask) + ring->ring_backup[ring->ring_backup_entries_to_copy++] = ring->ring[i]; +} + +void amdgpu_ring_backup_unprocessed_commands(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence) +{ + struct dma_fence *unprocessed; + struct dma_fence __rcu **ptr; + struct amdgpu_fence *fence; + u64 wptr, i, seqno; + + seqno = amdgpu_fence_read(ring); + wptr = ring->fence_drv.signalled_wptr; + ring->ring_backup_entries_to_copy = 0; + + for (i = seqno + 1; i <= ring->fence_drv.sync_seq; ++i) { + ptr = &ring->fence_drv.fences[i & ring->fence_drv.num_fences_mask]; + rcu_read_lock(); + unprocessed = rcu_dereference(*ptr); + + if (unprocessed && !dma_fence_is_signaled(unprocessed)) { + fence = container_of(unprocessed, struct amdgpu_fence, base); + + /* save everything if the ring is not guilty, otherwise + * just save the content from other contexts. + */ + if (!guilty_fence || (fence->context != guilty_fence->context)) + amdgpu_ring_backup_unprocessed_command(ring, wptr, + fence->wptr); + wptr = fence->wptr; + } + rcu_read_unlock(); + } +} + /* * Common fence implementation */ diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c index 206b70acb29a0..7d9bcb72e8dd3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c @@ -139,7 +139,6 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs, int vmid = AMDGPU_JOB_GET_VMID(job); bool need_pipe_sync = false; unsigned int cond_exec; - unsigned int i; int r = 0; @@ -156,6 +155,11 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs, gds_va = job->gds_va; init_shadow = job->init_shadow; af = &job->hw_fence; + /* Save the context of the job for reset handling. + * The driver needs this so it can skip the ring + * contents for guilty contexts. + */ + af->context = job->base.s_fence ? job->base.s_fence->finished.context : 0; } else { vm = NULL; fence_ctx = 0; @@ -307,8 +311,17 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs, ring->hw_prio == AMDGPU_GFX_PIPE_PRIO_HIGH) ring->funcs->emit_wave_limit(ring, false); + /* Save the wptr associated with this fence. + * This must be last for resets to work properly + * as we need to save the wptr associated with this + * fence so we know what rings contents to backup + * after we reset the queue. + */ + amdgpu_fence_save_wptr(*f); + amdgpu_ring_ib_end(ring); amdgpu_ring_commit(ring); + return 0; } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c index 2b58e353cca15..5cb7bf9420f70 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c @@ -90,8 +90,8 @@ static enum drm_gpu_sched_stat amdgpu_job_timedout(struct drm_sched_job *s_job) struct amdgpu_ring *ring = to_amdgpu_ring(s_job->sched); struct amdgpu_job *job = to_amdgpu_job(s_job); struct drm_wedge_task_info *info = NULL; - struct amdgpu_task_info *ti; struct amdgpu_device *adev = ring->adev; + struct amdgpu_task_info *ti; int idx, r; if (!drm_dev_enter(adev_to_drm(adev), &idx)) { @@ -134,7 +134,7 @@ static enum drm_gpu_sched_stat amdgpu_job_timedout(struct drm_sched_job *s_job) } else if (amdgpu_gpu_recovery && ring->funcs->reset) { dev_err(adev->dev, "Starting %s ring reset\n", s_job->sched->name); - r = amdgpu_ring_reset(ring, job->vmid, NULL); + r = amdgpu_ring_reset(ring, job->vmid, &job->hw_fence); if (!r) { atomic_inc(&ring->adev->gpu_reset_counter); dev_err(adev->dev, "Ring %s reset succeeded\n", diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c index 426834806fbf2..09d7681b7a754 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c @@ -99,6 +99,29 @@ int amdgpu_ring_alloc(struct amdgpu_ring *ring, unsigned int ndw) return 0; } +/** + * amdgpu_ring_alloc_reemit - allocate space on the ring buffer for reemit + * + * @ring: amdgpu_ring structure holding ring information + * @ndw: number of dwords to allocate in the ring buffer + * + * Allocate @ndw dwords in the ring buffer (all asics). + * doesn't check the max_dw limit as we may be reemitting + * several submissions. + */ +static void amdgpu_ring_alloc_reemit(struct amdgpu_ring *ring, unsigned int ndw) +{ + /* Align requested size with padding so unlock_commit can + * pad safely */ + ndw = (ndw + ring->funcs->align_mask) & ~ring->funcs->align_mask; + + ring->count_dw = ndw; + ring->wptr_old = ring->wptr; + + if (ring->funcs->begin_use) + ring->funcs->begin_use(ring); +} + /** amdgpu_ring_insert_nop - insert NOP packets * * @ring: amdgpu_ring structure holding ring information @@ -333,6 +356,12 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring, /* Initialize cached_rptr to 0 */ ring->cached_rptr = 0; + if (!ring->ring_backup) { + ring->ring_backup = kvzalloc(ring->ring_size, GFP_KERNEL); + if (!ring->ring_backup) + return -ENOMEM; + } + /* Allocate ring buffer */ if (ring->ring_obj == NULL) { r = amdgpu_bo_create_kernel(adev, ring->ring_size + ring->funcs->extra_dw, PAGE_SIZE, @@ -342,6 +371,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring, (void **)&ring->ring); if (r) { dev_err(adev->dev, "(%d) ring create failed\n", r); + kvfree(ring->ring_backup); return r; } amdgpu_ring_clear_ring(ring); @@ -385,6 +415,8 @@ void amdgpu_ring_fini(struct amdgpu_ring *ring) amdgpu_bo_free_kernel(&ring->ring_obj, &ring->gpu_addr, (void **)&ring->ring); + kvfree(ring->ring_backup); + ring->ring_backup = NULL; dma_fence_put(ring->vmid_wait); ring->vmid_wait = NULL; @@ -753,3 +785,38 @@ bool amdgpu_ring_sched_ready(struct amdgpu_ring *ring) return true; } + +void amdgpu_ring_reset_helper_begin(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence) +{ + /* Stop the scheduler to prevent anybody else from touching the ring buffer. */ + drm_sched_wqueue_stop(&ring->sched); + /* back up the non-guilty commands */ + amdgpu_ring_backup_unprocessed_commands(ring, guilty_fence); +} + +int amdgpu_ring_reset_helper_end(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence) +{ + unsigned int i; + int r; + + /* verify that the ring is functional */ + r = amdgpu_ring_test_ring(ring); + if (r) + return r; + + /* signal the fence of the bad job */ + if (guilty_fence) + amdgpu_fence_driver_guilty_force_completion(guilty_fence); + /* Re-emit the non-guilty commands */ + if (ring->ring_backup_entries_to_copy) { + amdgpu_ring_alloc_reemit(ring, ring->ring_backup_entries_to_copy); + for (i = 0; i < ring->ring_backup_entries_to_copy; i++) + amdgpu_ring_write(ring, ring->ring_backup[i]); + amdgpu_ring_commit(ring); + } + /* Start the scheduler again */ + drm_sched_wqueue_start(&ring->sched); + return 0; +} diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h index 784ba2ec354c7..309e7bb6001bd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h @@ -118,6 +118,7 @@ struct amdgpu_fence_driver { /* sync_seq is protected by ring emission lock */ uint32_t sync_seq; atomic_t last_seq; + u64 signalled_wptr; bool initialized; struct amdgpu_irq_src *irq_src; unsigned irq_type; @@ -141,6 +142,12 @@ struct amdgpu_fence { /* RB, DMA, etc. */ struct amdgpu_ring *ring; ktime_t start_timestamp; + + /* wptr for the fence for resets */ + u64 wptr; + /* fence context for resets */ + u64 context; + uint32_t seq; }; extern const struct drm_sched_backend_ops amdgpu_sched_ops; @@ -148,6 +155,8 @@ extern const struct drm_sched_backend_ops amdgpu_sched_ops; void amdgpu_fence_driver_clear_job_fences(struct amdgpu_ring *ring); void amdgpu_fence_driver_set_error(struct amdgpu_ring *ring, int error); void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring); +void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *fence); +void amdgpu_fence_save_wptr(struct dma_fence *fence); int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring); int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring, @@ -284,6 +293,9 @@ struct amdgpu_ring { struct amdgpu_bo *ring_obj; uint32_t *ring; + /* backups for resets */ + uint32_t *ring_backup; + unsigned int ring_backup_entries_to_copy; unsigned rptr_offs; u64 rptr_gpu_addr; volatile u32 *rptr_cpu_addr; @@ -550,4 +562,10 @@ int amdgpu_ib_pool_init(struct amdgpu_device *adev); void amdgpu_ib_pool_fini(struct amdgpu_device *adev); int amdgpu_ib_ring_tests(struct amdgpu_device *adev); bool amdgpu_ring_sched_ready(struct amdgpu_ring *ring); +void amdgpu_ring_backup_unprocessed_commands(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence); +void amdgpu_ring_reset_helper_begin(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence); +int amdgpu_ring_reset_helper_end(struct amdgpu_ring *ring, + struct amdgpu_fence *guilty_fence); #endif diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index af0f655dfd5b4..d5c0637d73928 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -765,6 +765,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, bool cleaner_shader_needed = false; bool pasid_mapping_needed = false; struct dma_fence *fence = NULL; + struct amdgpu_fence *af; unsigned int patch; int r; @@ -830,6 +831,9 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, r = amdgpu_fence_emit(ring, &fence, NULL, 0); if (r) return r; + /* this is part of the job's context */ + af = container_of(fence, struct amdgpu_fence, base); + af->context = job->base.s_fence ? job->base.s_fence->finished.context : 0; } if (vm_flush_needed) {