4.20-stable review patch. If anyone has any objections, please let me know.
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From: Chris Wilson chris@chris-wilson.co.uk
commit 280d479b310298dfeb1d6f9a1617eca37beb6ce4 upstream.
If we fail to pin the ggtt vma slot for the ppgtt page tables, we need to unwind the locals before reporting the error. Or else on subsequent attempts to bind the page tables into the ggtt, we will already believe that the vma has been pinned and continue on blithely. If something else should happen to be at that location, choas ensues.
Fixes: a2bbf7148342 ("drm/i915/gtt: Only keep gen6 page directories pinned while active") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Mika Kuoppala mika.kuoppala@linux.intel.com Cc: Matthew Auld matthew.william.auld@gmail.com Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Matthew Auld matthew.william.auld@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20181222030623.21710-1-chris@c... (cherry picked from commit d4de753526f4d99f541f1b6ed1d963005c09700c) Signed-off-by: Jani Nikula jani.nikula@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/i915_gem_gtt.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -2117,6 +2117,7 @@ static struct i915_vma *pd_vma_create(st int gen6_ppgtt_pin(struct i915_hw_ppgtt *base) { struct gen6_hw_ppgtt *ppgtt = to_gen6_ppgtt(base); + int err;
/* * Workaround the limited maximum vma->pin_count and the aliasing_ppgtt @@ -2132,9 +2133,17 @@ int gen6_ppgtt_pin(struct i915_hw_ppgtt * allocator works in address space sizes, so it's multiplied by page * size. We allocate at the top of the GTT to avoid fragmentation. */ - return i915_vma_pin(ppgtt->vma, - 0, GEN6_PD_ALIGN, - PIN_GLOBAL | PIN_HIGH); + err = i915_vma_pin(ppgtt->vma, + 0, GEN6_PD_ALIGN, + PIN_GLOBAL | PIN_HIGH); + if (err) + goto unpin; + + return 0; + +unpin: + ppgtt->pin_count = 0; + return err; }
void gen6_ppgtt_unpin(struct i915_hw_ppgtt *base)