From 319404df2f682ddabf98cbf6421bb43b951ca978 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Fri, 14 Aug 2015 18:35:27 +0300 Subject: drm/i915/bxt: work around HW coherency issue when accessing GPU seqno By running igt/store_dword_loop_render on BXT we can hit a coherency problem where the seqno written at GPU command completion time is not seen by the CPU. This results in __i915_wait_request seeing the stale seqno and not completing the request (not considering the lost interrupt/GPU reset mechanism). I also verified that this isn't a case of a lost interrupt, or that the command didn't complete somehow: when the coherency issue occured I read the seqno via an uncached GTT mapping too. While the cached version of the seqno still showed the stale value the one read via the uncached mapping was the correct one. Work around this issue by clflushing the corresponding CPU cacheline following any store of the seqno and preceding any reading of it. When reading it do this only when the caller expects a coherent view. v2: - fix using the proper logical && instead of a bitwise & (Jani, Mika) - limit the workaround to A stepping, on later steppings this HW issue is fixed v3: - use a separate get_seqno/set_seqno vfunc (Chris) Testcase: igt/store_dword_loop_render Signed-off-by: Imre Deak Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_ringbuffer.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.h') diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 2e85fda94963..95b0b4b55fa6 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -377,6 +377,13 @@ intel_ring_sync_index(struct intel_engine_cs *ring, return idx; } +static inline void +intel_flush_status_page(struct intel_engine_cs *ring, int reg) +{ + drm_clflush_virt_range(&ring->status_page.page_addr[reg], + sizeof(uint32_t)); +} + static inline u32 intel_read_status_page(struct intel_engine_cs *ring, int reg) -- cgit v1.2.3 From 01101fa7cc85fffc95798d1f67970dad96063fc6 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 3 Sep 2015 13:01:39 +0100 Subject: drm/i915: Refactor common ringbuffer allocation code A small, very small, step to sharing the duplicate code between execlists and legacy submission engines, starting with the ringbuffer allocation code. Signed-off-by: Chris Wilson Cc: Arun Siluvery Cc: Mika Kuoppala Cc: Dave Gordon Reviewed-by: Paulo Zanoni Reviewed-by: Mika Kuoppala Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_lrc.c | 49 +++++------------- drivers/gpu/drm/i915/intel_ringbuffer.c | 89 ++++++++++++++++++++------------- drivers/gpu/drm/i915/intel_ringbuffer.h | 8 +-- 3 files changed, 70 insertions(+), 76 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.h') diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 40cbba4ea4ba..28a712e7d2d0 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -2340,8 +2340,7 @@ void intel_lr_context_free(struct intel_context *ctx) i915_gem_object_ggtt_unpin(ctx_obj); } WARN_ON(ctx->engine[ring->id].pin_count); - intel_destroy_ringbuffer_obj(ringbuf); - kfree(ringbuf); + intel_ringbuffer_free(ringbuf); drm_gem_object_unreference(&ctx_obj->base); } } @@ -2442,42 +2441,20 @@ int intel_lr_context_deferred_create(struct intel_context *ctx, I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE); } - ringbuf = kzalloc(sizeof(*ringbuf), GFP_KERNEL); - if (!ringbuf) { - DRM_DEBUG_DRIVER("Failed to allocate ringbuffer %s\n", - ring->name); - ret = -ENOMEM; + ringbuf = intel_engine_create_ringbuffer(ring, 4 * PAGE_SIZE); + if (IS_ERR(ringbuf)) { + ret = PTR_ERR(ringbuf); goto error_unpin_ctx; } - ringbuf->ring = ring; - - ringbuf->size = 4 * PAGE_SIZE; - ringbuf->effective_size = ringbuf->size; - ringbuf->head = 0; - ringbuf->tail = 0; - ringbuf->last_retired_head = -1; - intel_ring_update_space(ringbuf); - - if (ringbuf->obj == NULL) { - ret = intel_alloc_ringbuffer_obj(dev, ringbuf); + if (is_global_default_ctx) { + ret = intel_pin_and_map_ringbuffer_obj(dev, ringbuf); if (ret) { - DRM_DEBUG_DRIVER( - "Failed to allocate ringbuffer obj %s: %d\n", - ring->name, ret); - goto error_free_rbuf; + DRM_ERROR( + "Failed to pin and map ringbuffer %s: %d\n", + ring->name, ret); + goto error_ringbuf; } - - if (is_global_default_ctx) { - ret = intel_pin_and_map_ringbuffer_obj(dev, ringbuf); - if (ret) { - DRM_ERROR( - "Failed to pin and map ringbuffer %s: %d\n", - ring->name, ret); - goto error_destroy_rbuf; - } - } - } ret = populate_lr_context(ctx, ctx_obj, ring, ringbuf); @@ -2519,10 +2496,8 @@ int intel_lr_context_deferred_create(struct intel_context *ctx, error: if (is_global_default_ctx) intel_unpin_ringbuffer_obj(ringbuf); -error_destroy_rbuf: - intel_destroy_ringbuffer_obj(ringbuf); -error_free_rbuf: - kfree(ringbuf); +error_ringbuf: + intel_ringbuffer_free(ringbuf); error_unpin_ctx: if (is_global_default_ctx) i915_gem_object_ggtt_unpin(ctx_obj); diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 6e6b8db996ef..20a75bb516ac 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1996,14 +1996,14 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, return 0; } -void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf) +static void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf) { drm_gem_object_unreference(&ringbuf->obj->base); ringbuf->obj = NULL; } -int intel_alloc_ringbuffer_obj(struct drm_device *dev, - struct intel_ringbuffer *ringbuf) +static int intel_alloc_ringbuffer_obj(struct drm_device *dev, + struct intel_ringbuffer *ringbuf) { struct drm_i915_gem_object *obj; @@ -2023,6 +2023,48 @@ int intel_alloc_ringbuffer_obj(struct drm_device *dev, return 0; } +struct intel_ringbuffer * +intel_engine_create_ringbuffer(struct intel_engine_cs *engine, int size) +{ + struct intel_ringbuffer *ring; + int ret; + + ring = kzalloc(sizeof(*ring), GFP_KERNEL); + if (ring == NULL) + return ERR_PTR(-ENOMEM); + + ring->ring = engine; + + ring->size = size; + /* Workaround an erratum on the i830 which causes a hang if + * the TAIL pointer points to within the last 2 cachelines + * of the buffer. + */ + ring->effective_size = size; + if (IS_I830(engine->dev) || IS_845G(engine->dev)) + ring->effective_size -= 2 * CACHELINE_BYTES; + + ring->last_retired_head = -1; + intel_ring_update_space(ring); + + ret = intel_alloc_ringbuffer_obj(engine->dev, ring); + if (ret) { + DRM_ERROR("Failed to allocate ringbuffer %s: %d\n", + engine->name, ret); + kfree(ring); + return ERR_PTR(ret); + } + + return ring; +} + +void +intel_ringbuffer_free(struct intel_ringbuffer *ring) +{ + intel_destroy_ringbuffer_obj(ring); + kfree(ring); +} + static int intel_init_ring_buffer(struct drm_device *dev, struct intel_engine_cs *ring) { @@ -2031,22 +2073,20 @@ static int intel_init_ring_buffer(struct drm_device *dev, WARN_ON(ring->buffer); - ringbuf = kzalloc(sizeof(*ringbuf), GFP_KERNEL); - if (!ringbuf) - return -ENOMEM; - ring->buffer = ringbuf; - ring->dev = dev; INIT_LIST_HEAD(&ring->active_list); INIT_LIST_HEAD(&ring->request_list); INIT_LIST_HEAD(&ring->execlist_queue); i915_gem_batch_pool_init(dev, &ring->batch_pool); - ringbuf->size = 32 * PAGE_SIZE; - ringbuf->ring = ring; memset(ring->semaphore.sync_seqno, 0, sizeof(ring->semaphore.sync_seqno)); init_waitqueue_head(&ring->irq_queue); + ringbuf = intel_engine_create_ringbuffer(ring, 32 * PAGE_SIZE); + if (IS_ERR(ringbuf)) + return PTR_ERR(ringbuf); + ring->buffer = ringbuf; + if (I915_NEED_GFX_HWS(dev)) { ret = init_status_page(ring); if (ret) @@ -2058,15 +2098,6 @@ static int intel_init_ring_buffer(struct drm_device *dev, goto error; } - WARN_ON(ringbuf->obj); - - ret = intel_alloc_ringbuffer_obj(dev, ringbuf); - if (ret) { - DRM_ERROR("Failed to allocate ringbuffer %s: %d\n", - ring->name, ret); - goto error; - } - ret = intel_pin_and_map_ringbuffer_obj(dev, ringbuf); if (ret) { DRM_ERROR("Failed to pin and map ringbuffer %s: %d\n", @@ -2075,14 +2106,6 @@ static int intel_init_ring_buffer(struct drm_device *dev, goto error; } - /* Workaround an erratum on the i830 which causes a hang if - * the TAIL pointer points to within the last 2 cachelines - * of the buffer. - */ - ringbuf->effective_size = ringbuf->size; - if (IS_I830(dev) || IS_845G(dev)) - ringbuf->effective_size -= 2 * CACHELINE_BYTES; - ret = i915_cmd_parser_init_ring(ring); if (ret) goto error; @@ -2090,7 +2113,7 @@ static int intel_init_ring_buffer(struct drm_device *dev, return 0; error: - kfree(ringbuf); + intel_ringbuffer_free(ringbuf); ring->buffer = NULL; return ret; } @@ -2098,19 +2121,18 @@ error: void intel_cleanup_ring_buffer(struct intel_engine_cs *ring) { struct drm_i915_private *dev_priv; - struct intel_ringbuffer *ringbuf; if (!intel_ring_initialized(ring)) return; dev_priv = to_i915(ring->dev); - ringbuf = ring->buffer; intel_stop_ring_buffer(ring); WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0); - intel_unpin_ringbuffer_obj(ringbuf); - intel_destroy_ringbuffer_obj(ringbuf); + intel_unpin_ringbuffer_obj(ring->buffer); + intel_ringbuffer_free(ring->buffer); + ring->buffer = NULL; if (ring->cleanup) ring->cleanup(ring); @@ -2119,9 +2141,6 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring) i915_cmd_parser_fini_ring(ring); i915_gem_batch_pool_fini(&ring->batch_pool); - - kfree(ringbuf); - ring->buffer = NULL; } static int ring_wait_for_space(struct intel_engine_cs *ring, int n) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 95b0b4b55fa6..49fa41dc0eb6 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -420,12 +420,12 @@ intel_write_status_page(struct intel_engine_cs *ring, #define I915_GEM_HWS_SCRATCH_INDEX 0x40 #define I915_GEM_HWS_SCRATCH_ADDR (I915_GEM_HWS_SCRATCH_INDEX << MI_STORE_DWORD_INDEX_SHIFT) -void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf); +struct intel_ringbuffer * +intel_engine_create_ringbuffer(struct intel_engine_cs *engine, int size); int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, struct intel_ringbuffer *ringbuf); -void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf); -int intel_alloc_ringbuffer_obj(struct drm_device *dev, - struct intel_ringbuffer *ringbuf); +void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf); +void intel_ringbuffer_free(struct intel_ringbuffer *ring); void intel_stop_ring_buffer(struct intel_engine_cs *ring); void intel_cleanup_ring_buffer(struct intel_engine_cs *ring); -- cgit v1.2.3