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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-11-18 23:02:40 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-11-19 15:12:46 +0000 |
| commit | a266bf42006004306dd48a9082c35dfbff153307 (patch) | |
| tree | 27a511edac47243c18a786500abf58b15910e7f7 /drivers/gpu/drm/i915/gt/intel_ring.c | |
| parent | b6422694c5853f7a4faf00431c9d7b5368138152 (diff) | |
| download | linux-a266bf42006004306dd48a9082c35dfbff153307.tar.bz2 | |
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.c | 13 |
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) |