summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/gt/intel_ring.c
diff options
context:
space:
mode:
authorChris Wilson <chris@chris-wilson.co.uk>2019-11-18 23:02:40 +0000
committerChris Wilson <chris@chris-wilson.co.uk>2019-11-19 15:12:46 +0000
commita266bf42006004306dd48a9082c35dfbff153307 (patch)
tree27a511edac47243c18a786500abf58b15910e7f7 /drivers/gpu/drm/i915/gt/intel_ring.c
parentb6422694c5853f7a4faf00431c9d7b5368138152 (diff)
downloadlinux-sh-a266bf42006004306dd48a9082c35dfbff153307.tar.gz
drm/i915/gt: Make intel_ring_unpin() safe for concurrent pint
In order to avoid some nasty mutex inversions, commit 09c5ab384f6f ("drm/i915: Keep rings pinned while the context is active") allowed the intel_ring unpinning to be run concurrently with the next context pinning it. Thus each step in intel_ring_unpin() needed to be atomic and ordered in a nice onion with intel_ring_pin() so that the lifetimes overlapped and were always safe. Sadly, a few steps in intel_ring_unpin() were overlooked, such as closing the read/write pointers of the ring and discarding the intel_ring.vaddr, as these steps were not serialised with intel_ring_pin() and so could leave the ring in disarray. Fixes: 09c5ab384f6f ("drm/i915: Keep rings pinned while the context is active") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191118230254.2615942-6-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_ring.c')
-rw-r--r--drivers/gpu/drm/i915/gt/intel_ring.c13
1 files changed, 4 insertions, 9 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c
index ece20504d240..374b28f13ca0 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring.c
@@ -57,9 +57,10 @@ int intel_ring_pin(struct intel_ring *ring)
i915_vma_make_unshrinkable(vma);
- GEM_BUG_ON(ring->vaddr);
- ring->vaddr = addr;
+ /* Discard any unused bytes beyond that submitted to hw. */
+ intel_ring_reset(ring, ring->emit);
+ ring->vaddr = addr;
return 0;
err_ring:
@@ -85,20 +86,14 @@ void intel_ring_unpin(struct intel_ring *ring)
if (!atomic_dec_and_test(&ring->pin_count))
return;
- /* Discard any unused bytes beyond that submitted to hw. */
- intel_ring_reset(ring, ring->emit);
-
i915_vma_unset_ggtt_write(vma);
if (i915_vma_is_map_and_fenceable(vma))
i915_vma_unpin_iomap(vma);
else
i915_gem_object_unpin_map(vma->obj);
- GEM_BUG_ON(!ring->vaddr);
- ring->vaddr = NULL;
-
- i915_vma_unpin(vma);
i915_vma_make_purgeable(vma);
+ i915_vma_unpin(vma);
}
static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)