drm/amdgpu: rework TLB flushing

Instead of tracking the VM updates through the dependencies just use a
sequence counter for page table updates which indicates the need to
flush the TLB.

This reduces the need to flush the TLB drastically.

v2: squash in NULL check fix (Christian)

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 0 insertions, 20 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
index 05e1af9998a3..edd49dd27422 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -51,7 +51,6 @@ static struct kmem_cache *amdgpu_sync_slab;
 void amdgpu_sync_create(struct amdgpu_sync *sync)
 {
 	hash_init(sync->fences);
-	sync->last_vm_update = 0;
 }
 
 /**
@@ -171,23 +170,6 @@ int amdgpu_sync_fence(struct amdgpu_sync *sync, struct dma_fence *f)
 	return 0;
 }
 
-/**
- * amdgpu_sync_vm_fence - remember to sync to this VM fence
- *
- * @sync: sync object to add fence to
- * @fence: the VM fence to add
- *
- * Add the fence to the sync object and remember it as VM update.
- */
-int amdgpu_sync_vm_fence(struct amdgpu_sync *sync, struct dma_fence *fence)
-{
-	if (!fence)
-		return 0;
-
-	sync->last_vm_update = max(sync->last_vm_update, fence->seqno);
-	return amdgpu_sync_fence(sync, fence);
-}
-
 /* Determine based on the owner and mode if we should sync to a fence or not */
 static bool amdgpu_sync_test_fence(struct amdgpu_device *adev,
 				   enum amdgpu_sync_mode mode,
@@ -376,8 +358,6 @@ int amdgpu_sync_clone(struct amdgpu_sync *source, struct amdgpu_sync *clone)
 		}
 	}
 
-	clone->last_vm_update = source->last_vm_update;
-
 	return 0;
 }