Re: [PATCH v3 1/3] drm/i915: pass a pointer for tlb seqno at vma_invalidate_tlb()

[Tvrtko Ursulin]

On 04/08/2022 08:37, Mauro Carvalho Chehab wrote:
WRITE_ONCE() should happen at the original var, not on a local
copy of it.

Fixes: 5d36acb7198b ("drm/i915/gt: Batch TLB invalidations")

Cc: stable I think, since the above one was. So both hit 5.21 (or 6.1) 
together.

Regards,

Tvrtko

Signed-off-by: Mauro Carvalho Chehab <mche...@kernel.org>
---

To avoid mailbombing on a large number of people, only mailing lists were C/C 
on the cover.
See [PATCH v3 0/3] at: 
https://lore.kernel.org/all/cover.1659598090.git.mche...@kernel.org/

  drivers/gpu/drm/i915/gt/intel_ppgtt.c | 2 +-
  drivers/gpu/drm/i915/i915_vma.c       | 6 +++---
  drivers/gpu/drm/i915/i915_vma.h       | 2 +-
  3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c 
b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
index 2da6c82a8bd2..6ee8d1127016 100644
--- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
@@ -211,7 +211,7 @@ void ppgtt_unbind_vma(struct i915_address_space *vm,
  
  	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
        if (vma_res->tlb)
-               vma_invalidate_tlb(vm, *vma_res->tlb);
+               vma_invalidate_tlb(vm, vma_res->tlb);
  }
  
  static unsigned long pd_count(u64 size, int shift)
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 84a9ccbc5fc5..260371716490 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -1308,7 +1308,7 @@ I915_SELFTEST_EXPORT int i915_vma_get_pages(struct 
i915_vma *vma)
        return err;
  }
  
-void vma_invalidate_tlb(struct i915_address_space *vm, u32 tlb)
+void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb)
  {
        /*
         * Before we release the pages that were bound by this vma, we
@@ -1318,7 +1318,7 @@ void vma_invalidate_tlb(struct i915_address_space *vm, 
u32 tlb)
         * the most recent TLB invalidation seqno, and if we have not yet
         * flushed the TLBs upon release, perform a full invalidation.
         */
-       WRITE_ONCE(tlb, intel_gt_next_invalidate_tlb_full(vm->gt));
+       WRITE_ONCE(*tlb, intel_gt_next_invalidate_tlb_full(vm->gt));
  }
  
  static void __vma_put_pages(struct i915_vma *vma, unsigned int count)
@@ -1971,7 +1971,7 @@ struct dma_fence *__i915_vma_evict(struct i915_vma *vma, 
bool async)
                        dma_fence_put(unbind_fence);
                        unbind_fence = NULL;
                }
-               vma_invalidate_tlb(vma->vm, vma->obj->mm.tlb);
+               vma_invalidate_tlb(vma->vm, &vma->obj->mm.tlb);
        }
  
  	/*
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 5048eed536da..33a58f605d75 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -213,7 +213,7 @@ bool i915_vma_misplaced(const struct i915_vma *vma,
                        u64 size, u64 alignment, u64 flags);
  void __i915_vma_set_map_and_fenceable(struct i915_vma *vma);
  void i915_vma_revoke_mmap(struct i915_vma *vma);
-void vma_invalidate_tlb(struct i915_address_space *vm, u32 tlb);
+void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb);
  struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async);
  int __i915_vma_unbind(struct i915_vma *vma);
  int __must_check i915_vma_unbind(struct i915_vma *vma);