drm/amdgpu: Update PTE flags with TF enabled

This patch updates the PTE flags when translate further (TF) is
enabled:
- With translate_further enabled, invalid PTEs can be 0. Reading
  consecutive invalid PTEs as 0 is considered a fault. To prevent
  this, ensure invalid PTEs have at least 1 bit set.
- The current invalid PTE flags settings to translate a retry fault
  into a no-retry fault, doesn't work with TF enabled. As a result,
  update invalid PTE flags settings which works for both TF enabled
  and disabled case.

Fixes: 352e683b ("drm/amdgpu: Enable translate_further to extend UTCL2 reach")
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -2484,8 +2484,7 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
 		/* Intentionally setting invalid PTE flag
 		 * combination to force a no-retry-fault
 		 */
-		flags = AMDGPU_PTE_EXECUTABLE | AMDGPU_PDE_PTE |
-			AMDGPU_PTE_TF;
+		flags = AMDGPU_PTE_SNOOPED | AMDGPU_PTE_PRT;
 		value = 0;
 	} else if (amdgpu_vm_fault_stop == AMDGPU_VM_FAULT_STOP_NEVER) {
 		/* Redirect the access to the dummy page */

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -1103,10 +1103,13 @@ static void gmc_v9_0_get_vm_pde(struct amdgpu_device *adev, int level,
 			*flags |= AMDGPU_PDE_BFS(0x9);
 
 	} else if (level == AMDGPU_VM_PDB0) {
-		if (*flags & AMDGPU_PDE_PTE)
+		if (*flags & AMDGPU_PDE_PTE) {
 			*flags &= ~AMDGPU_PDE_PTE;
-		else
+			if (!(*flags & AMDGPU_PTE_VALID))
+				*addr |= 1 << PAGE_SHIFT;
+		} else {
 			*flags |= AMDGPU_PTE_TF;
+		}
 	}
 }