From 89dd019a8a99e1a08c9c724dc2831c2ec3c050a3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 11 Feb 2020 20:56:14 +0000 Subject: [PATCH] drm/i915: Poison rings after use On retiring the request, we should not re-use these elements in the ring (at least not until we fill the ringbuffer and knowingly reuse the space). Leave behind some poison to (hopefully) trap ourselves if we make a mistake. Suggested-by: Mika Kuoppala Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20200211205615.1190127-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_request.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 1adb8cf..6daf18d 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -203,6 +203,19 @@ static void free_capture_list(struct i915_request *request) } } +static void __i915_request_fill(struct i915_request *rq, u8 val) +{ + void *vaddr = rq->ring->vaddr; + u32 head; + + head = rq->infix; + if (rq->postfix < head) { + memset(vaddr + head, val, rq->ring->size - head); + head = 0; + } + memset(vaddr + head, val, rq->postfix - head); +} + static void remove_from_engine(struct i915_request *rq) { struct intel_engine_cs *engine, *locked; @@ -247,6 +260,9 @@ bool i915_request_retire(struct i915_request *rq) */ GEM_BUG_ON(!list_is_first(&rq->link, &i915_request_timeline(rq)->requests)); + if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) + /* Poison before we release our space in the ring */ + __i915_request_fill(rq, POISON_FREE); rq->ring->head = rq->postfix; /* @@ -1179,9 +1195,6 @@ i915_request_await_object(struct i915_request *to, void i915_request_skip(struct i915_request *rq, int error) { - void *vaddr = rq->ring->vaddr; - u32 head; - GEM_BUG_ON(!IS_ERR_VALUE((long)error)); dma_fence_set_error(&rq->fence, error); @@ -1193,12 +1206,7 @@ void i915_request_skip(struct i915_request *rq, int error) * context, clear out all the user operations leaving the * breadcrumb at the end (so we get the fence notifications). */ - head = rq->infix; - if (rq->postfix < head) { - memset(vaddr + head, 0, rq->ring->size - head); - head = 0; - } - memset(vaddr + head, 0, rq->postfix - head); + __i915_request_fill(rq, 0); rq->infix = rq->postfix; } -- 2.7.4