From b4558b46d58e872114e96647cbd6a75ff7280f86 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Fri, 18 Jul 2014 02:19:40 -0700 Subject: [PATCH] drm/i915: Fix possible overflow when recording semaphore states. semaphore _sync_seqno, _seqno and _mbox are smaller than number of rings. This optimization is to remove the ring itself from the list and the logic to do that is at intel_ring_sync_index as below: /* * rcs -> 0 = vcs, 1 = bcs, 2 = vecs, 3 = vcs2; * vcs -> 0 = bcs, 1 = vecs, 2 = vcs2, 3 = rcs; * bcs -> 0 = vecs, 1 = vcs2. 2 = rcs, 3 = vcs; * vecs -> 0 = vcs2, 1 = rcs, 2 = vcs, 3 = bcs; * vcs2 -> 0 = rcs, 1 = vcs, 2 = bcs, 3 = vecs; */ v2: Skip when from == to (Damien). v3: avoid computing idx when from == to (Damien). use ring == to instead of ring->id == to->id (Damien). use continue instead of return (Rodrigo). v4: avoid all unecessary computation (Damien). reduce idx to loop scope (Damien). Cc: Damien Lespiau Cc: Ben Widawsky Signed-off-by: Rodrigo Vivi Reviewed-by: Damien Lespiau Reviewed-by: Ben Widawsky Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gpu_error.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 9faebbc22191..0b3f69439451 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -764,7 +764,7 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv, struct intel_engine_cs *ring, struct drm_i915_error_ring *ering) { - struct intel_engine_cs *useless; + struct intel_engine_cs *to; int i; if (!i915_semaphore_is_enabled(dev_priv->dev)) @@ -776,13 +776,20 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv, dev_priv->semaphore_obj, &dev_priv->gtt.base); - for_each_ring(useless, dev_priv, i) { - u16 signal_offset = - (GEN8_SIGNAL_OFFSET(ring, i) & PAGE_MASK) / 4; - u32 *tmp = error->semaphore_obj->pages[0]; + for_each_ring(to, dev_priv, i) { + int idx; + u16 signal_offset; + u32 *tmp; - ering->semaphore_mboxes[i] = tmp[signal_offset]; - ering->semaphore_seqno[i] = ring->semaphore.sync_seqno[i]; + if (ring == to) + continue; + + signal_offset = (GEN8_SIGNAL_OFFSET(ring, i) & PAGE_MASK) / 4; + tmp = error->semaphore_obj->pages[0]; + idx = intel_ring_sync_index(ring, to); + + ering->semaphore_mboxes[idx] = tmp[signal_offset]; + ering->semaphore_seqno[idx] = ring->semaphore.sync_seqno[idx]; } } -- 2.34.1