drm/amdgpu: Update PDEs flush TLB if PTB/PDB moved

Flush TLBs when existing PDEs are updated because a PTB or PDB moved,
but avoids unnecessary TLB flushes when new PDBs or PTBs are added to
the page table, which commonly happens when memory is mapped for the
first time.

Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 2ceeaa4c793aec1243386b81c6fd93b08058ec8f..109d8dd71c116f443f7a91530469c2503db6b63c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -679,6 +679,7 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
 {
        struct amdgpu_vm_update_params params;
        struct amdgpu_vm_bo_base *entry;
+       bool flush_tlb_needed = false;
        int r, idx;
 
        if (list_empty(&vm->relocated))
@@ -697,6 +698,9 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
                goto error;
 
        list_for_each_entry(entry, &vm->relocated, vm_status) {
+               /* vm_flush_needed after updating moved PDEs */
+               flush_tlb_needed |= entry->moved;
+
                r = amdgpu_vm_pde_update(&params, entry);
                if (r)
                        goto error;
@@ -706,8 +710,8 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
        if (r)
                goto error;
 
-       /* vm_flush_needed after updating PDEs */
-       atomic64_inc(&vm->tlb_seq);
+       if (flush_tlb_needed)
+               atomic64_inc(&vm->tlb_seq);
 
        while (!list_empty(&vm->relocated)) {
                entry = list_first_entry(&vm->relocated,