drm/i915: pass a pointer for tlb seqno at vma_invalidate_tlb()

WRITE_ONCE() should happen at the original var, not on a local
copy of it.

Cc: stable@vger.kernel.org
Fixes: 5d36acb7 ("drm/i915/gt: Batch TLB invalidations")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[added cc-stable while merging it]
Link: https://patchwork.freedesktop.org/patch/msgid/f9550e6bacea10131ff40dd8981b69eb9251cdcd.1659598090.git.mchehab@kernel.org

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)

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);
 	}
 
 	/*

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);