From acb868d3d710b09a356d848e0cd44d9713a9e274 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 26 Sep 2012 13:47:30 +0100 Subject: [PATCH] drm/i915: Disallow preallocation of requests The intention was to allow the caller to avoid a failure to queue a request having already written commands to the ring. However, this is a moot point as the i915_add_request() can fail for other reasons than a mere allocation failure and those failure cases are more likely than ENOMEM. So the overlay code already had to handle i915_add_request() failures, and due to commit 3bb73aba1ed5198a2c1dfaac4f3c95459930d84a Author: Chris Wilson Date: Fri Jul 20 12:40:59 2012 +0100 drm/i915: Allow late allocation of request for i915_add_request() the error handling code in intel_overlay.c was subject to causing double-frees, as found by coverity. Rather than further complicate i915_add_request() and callers, realise the battle is lost and adapt intel_overlay.c to take advantage of the late allocation of requests. v2: Handle callers passing in a NULL seqno. v3: Ditto. This time for sure. Signed-off-by: Chris Wilson Reviewed-by: Jani Nikula Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 2 +- drivers/gpu/drm/i915/i915_gem.c | 15 ++++---- drivers/gpu/drm/i915/intel_overlay.c | 72 ++++++++---------------------------- 3 files changed, 24 insertions(+), 65 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 4f2831a..d5138c3 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1427,7 +1427,7 @@ int __must_check i915_gpu_idle(struct drm_device *dev); int __must_check i915_gem_idle(struct drm_device *dev); int i915_add_request(struct intel_ring_buffer *ring, struct drm_file *file, - struct drm_i915_gem_request *request); + u32 *seqno); int __must_check i915_wait_seqno(struct intel_ring_buffer *ring, uint32_t seqno); int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf); diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 53de95c..04b0c07 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1956,11 +1956,12 @@ i915_gem_next_request_seqno(struct intel_ring_buffer *ring) int i915_add_request(struct intel_ring_buffer *ring, struct drm_file *file, - struct drm_i915_gem_request *request) + u32 *out_seqno) { drm_i915_private_t *dev_priv = ring->dev->dev_private; - uint32_t seqno; + struct drm_i915_gem_request *request; u32 request_ring_position; + u32 seqno; int was_empty; int ret; @@ -1975,11 +1976,9 @@ i915_add_request(struct intel_ring_buffer *ring, if (ret) return ret; - if (request == NULL) { - request = kmalloc(sizeof(*request), GFP_KERNEL); - if (request == NULL) - return -ENOMEM; - } + request = kmalloc(sizeof(*request), GFP_KERNEL); + if (request == NULL) + return -ENOMEM; seqno = i915_gem_next_request_seqno(ring); @@ -2031,6 +2030,8 @@ i915_add_request(struct intel_ring_buffer *ring, } } + if (out_seqno) + *out_seqno = seqno; return 0; } diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c index afd0f30..555912f 100644 --- a/drivers/gpu/drm/i915/intel_overlay.c +++ b/drivers/gpu/drm/i915/intel_overlay.c @@ -210,7 +210,6 @@ static void intel_overlay_unmap_regs(struct intel_overlay *overlay, } static int intel_overlay_do_wait_request(struct intel_overlay *overlay, - struct drm_i915_gem_request *request, void (*tail)(struct intel_overlay *)) { struct drm_device *dev = overlay->dev; @@ -219,12 +218,10 @@ static int intel_overlay_do_wait_request(struct intel_overlay *overlay, int ret; BUG_ON(overlay->last_flip_req); - ret = i915_add_request(ring, NULL, request); - if (ret) { - kfree(request); - return ret; - } - overlay->last_flip_req = request->seqno; + ret = i915_add_request(ring, NULL, &overlay->last_flip_req); + if (ret) + return ret; + overlay->flip_tail = tail; ret = i915_wait_seqno(ring, overlay->last_flip_req); if (ret) @@ -241,7 +238,6 @@ static int intel_overlay_on(struct intel_overlay *overlay) struct drm_device *dev = overlay->dev; struct drm_i915_private *dev_priv = dev->dev_private; struct intel_ring_buffer *ring = &dev_priv->ring[RCS]; - struct drm_i915_gem_request *request; int ret; BUG_ON(overlay->active); @@ -249,17 +245,9 @@ static int intel_overlay_on(struct intel_overlay *overlay) WARN_ON(IS_I830(dev) && !(dev_priv->quirks & QUIRK_PIPEA_FORCE)); - request = kzalloc(sizeof(*request), GFP_KERNEL); - if (request == NULL) { - ret = -ENOMEM; - goto out; - } - ret = intel_ring_begin(ring, 4); - if (ret) { - kfree(request); - goto out; - } + if (ret) + return ret; intel_ring_emit(ring, MI_OVERLAY_FLIP | MI_OVERLAY_ON); intel_ring_emit(ring, overlay->flip_addr | OFC_UPDATE); @@ -267,9 +255,7 @@ static int intel_overlay_on(struct intel_overlay *overlay) intel_ring_emit(ring, MI_NOOP); intel_ring_advance(ring); - ret = intel_overlay_do_wait_request(overlay, request, NULL); -out: - return ret; + return intel_overlay_do_wait_request(overlay, NULL); } /* overlay needs to be enabled in OCMD reg */ @@ -279,17 +265,12 @@ static int intel_overlay_continue(struct intel_overlay *overlay, struct drm_device *dev = overlay->dev; drm_i915_private_t *dev_priv = dev->dev_private; struct intel_ring_buffer *ring = &dev_priv->ring[RCS]; - struct drm_i915_gem_request *request; u32 flip_addr = overlay->flip_addr; u32 tmp; int ret; BUG_ON(!overlay->active); - request = kzalloc(sizeof(*request), GFP_KERNEL); - if (request == NULL) - return -ENOMEM; - if (load_polyphase_filter) flip_addr |= OFC_UPDATE; @@ -299,22 +280,14 @@ static int intel_overlay_continue(struct intel_overlay *overlay, DRM_DEBUG("overlay underrun, DOVSTA: %x\n", tmp); ret = intel_ring_begin(ring, 2); - if (ret) { - kfree(request); + if (ret) return ret; - } + intel_ring_emit(ring, MI_OVERLAY_FLIP | MI_OVERLAY_CONTINUE); intel_ring_emit(ring, flip_addr); intel_ring_advance(ring); - ret = i915_add_request(ring, NULL, request); - if (ret) { - kfree(request); - return ret; - } - - overlay->last_flip_req = request->seqno; - return 0; + return i915_add_request(ring, NULL, &overlay->last_flip_req); } static void intel_overlay_release_old_vid_tail(struct intel_overlay *overlay) @@ -350,15 +323,10 @@ static int intel_overlay_off(struct intel_overlay *overlay) struct drm_i915_private *dev_priv = dev->dev_private; struct intel_ring_buffer *ring = &dev_priv->ring[RCS]; u32 flip_addr = overlay->flip_addr; - struct drm_i915_gem_request *request; int ret; BUG_ON(!overlay->active); - request = kzalloc(sizeof(*request), GFP_KERNEL); - if (request == NULL) - return -ENOMEM; - /* According to intel docs the overlay hw may hang (when switching * off) without loading the filter coeffs. It is however unclear whether * this applies to the disabling of the overlay or to the switching off @@ -366,10 +334,9 @@ static int intel_overlay_off(struct intel_overlay *overlay) flip_addr |= OFC_UPDATE; ret = intel_ring_begin(ring, 6); - if (ret) { - kfree(request); + if (ret) return ret; - } + /* wait for overlay to go idle */ intel_ring_emit(ring, MI_OVERLAY_FLIP | MI_OVERLAY_CONTINUE); intel_ring_emit(ring, flip_addr); @@ -380,8 +347,7 @@ static int intel_overlay_off(struct intel_overlay *overlay) intel_ring_emit(ring, MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP); intel_ring_advance(ring); - return intel_overlay_do_wait_request(overlay, request, - intel_overlay_off_tail); + return intel_overlay_do_wait_request(overlay, intel_overlay_off_tail); } /* recover from an interruption due to a signal @@ -426,24 +392,16 @@ static int intel_overlay_release_old_vid(struct intel_overlay *overlay) return 0; if (I915_READ(ISR) & I915_OVERLAY_PLANE_FLIP_PENDING_INTERRUPT) { - struct drm_i915_gem_request *request; - /* synchronous slowpath */ - request = kzalloc(sizeof(*request), GFP_KERNEL); - if (request == NULL) - return -ENOMEM; - ret = intel_ring_begin(ring, 2); - if (ret) { - kfree(request); + if (ret) return ret; - } intel_ring_emit(ring, MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP); intel_ring_emit(ring, MI_NOOP); intel_ring_advance(ring); - ret = intel_overlay_do_wait_request(overlay, request, + ret = intel_overlay_do_wait_request(overlay, intel_overlay_release_old_vid_tail); if (ret) return ret; -- 2.7.4