From 461fa7b0ac565ef25c1da0ced31005dd437883a7 Mon Sep 17 00:00:00 2001 From: Ken Xue Date: Fri, 11 Feb 2022 16:18:46 -0500 Subject: drm/amdgpu: remove ctx->lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit KMD reports a warning on holding a lock from drm_syncobj_find_fence, when running amdgpu_test case “syncobj timeline test”. ctx->lock was designed to prevent concurrent "amdgpu_ctx_wait_prev_fence" calls and avoid dead reservation lock from GPU reset. since no reservation lock is held in latest GPU reset any more, ctx->lock can be simply removed and concurrent "amdgpu_ctx_wait_prev_fence" call also can be prevented by PD root bo reservation lock. call stacks: ================= //hold lock amdgpu_cs_ioctl->amdgpu_cs_parser_init->mutex_lock(&parser->ctx->lock); … //report warning amdgpu_cs_dependencies->amdgpu_cs_process_syncobj_timeline_in_dep \ ->amdgpu_syncobj_lookup_and_add_to_sync -> drm_syncobj_find_fence \ -> lockdep_assert_none_held_once … amdgpu_cs_ioctl->amdgpu_cs_parser_fini->mutex_unlock(&parser->ctx->lock); Signed-off-by: Ken Xue Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 16 +++++++++++----- drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 -- drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h | 1 - 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index a34be65c9eaa..af12256e1bd3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -127,8 +127,6 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs goto free_chunk; } - mutex_lock(&p->ctx->lock); - /* skip guilty context job */ if (atomic_read(&p->ctx->guilty) == 1) { ret = -ECANCELED; @@ -585,6 +583,16 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p, } } + /* Move fence waiting after getting reservation lock of + * PD root. Then there is no need on a ctx mutex lock. + */ + r = amdgpu_ctx_wait_prev_fence(p->ctx, p->entity); + if (unlikely(r != 0)) { + if (r != -ERESTARTSYS) + DRM_ERROR("amdgpu_ctx_wait_prev_fence failed.\n"); + goto error_validate; + } + amdgpu_cs_get_threshold_for_moves(p->adev, &p->bytes_moved_threshold, &p->bytes_moved_vis_threshold); p->bytes_moved = 0; @@ -700,7 +708,6 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser, int error, dma_fence_put(parser->fence); if (parser->ctx) { - mutex_unlock(&parser->ctx->lock); amdgpu_ctx_put(parser->ctx); } if (parser->bo_list) @@ -944,7 +951,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev, if (parser->job->uf_addr && ring->funcs->no_user_fence) return -EINVAL; - return amdgpu_ctx_wait_prev_fence(parser->ctx, parser->entity); + return 0; } static int amdgpu_cs_process_fence_dep(struct amdgpu_cs_parser *p, @@ -1363,7 +1370,6 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp) goto out; r = amdgpu_cs_submit(&parser, cs); - out: amdgpu_cs_parser_fini(&parser, r, reserved_buffers); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c index 2c929fa40379..1c72f6095f08 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c @@ -230,7 +230,6 @@ static int amdgpu_ctx_init(struct amdgpu_device *adev, kref_init(&ctx->refcount); spin_lock_init(&ctx->ring_lock); - mutex_init(&ctx->lock); ctx->reset_counter = atomic_read(&adev->gpu_reset_counter); ctx->reset_counter_query = ctx->reset_counter; @@ -352,7 +351,6 @@ static void amdgpu_ctx_fini(struct kref *ref) } } amdgpu_ctx_set_stable_pstate(ctx, AMDGPU_CTX_STABLE_PSTATE_NONE); - mutex_destroy(&ctx->lock); kfree(ctx); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h index 142f2f87d44c..d0cbfcea90f7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h @@ -49,7 +49,6 @@ struct amdgpu_ctx { bool preamble_presented; int32_t init_priority; int32_t override_priority; - struct mutex lock; atomic_t guilty; unsigned long ras_counter_ce; unsigned long ras_counter_ue; -- cgit v1.2.3