drm/amdgpu: make sure retry faults are handled in a work item on Vega

Looks like we can't enabled the IH1/IH2 feature for Vega20, make sure
retry faults are handled on a separate ring anyway.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -525,14 +525,29 @@ static int gmc_v9_0_process_interrupt(struct amdgpu_device *adev,
 	addr = (u64)entry->src_data[0] << 12;
 	addr |= ((u64)entry->src_data[1] & 0xf) << 44;
 
-	if (retry_fault && amdgpu_gmc_filter_faults(adev, addr, entry->pasid,
-						    entry->timestamp))
-		return 1; /* This also prevents sending it to KFD */
-
-	/* If it's the first fault for this address, process it normally */
-	if (retry_fault && !in_interrupt() &&
-	    amdgpu_vm_handle_fault(adev, entry->pasid, addr))
-		return 1; /* This also prevents sending it to KFD */
+	if (retry_fault) {
+		/* Returning 1 here also prevents sending the IV to the KFD */
+
+		/* Process it onyl if it's the first fault for this address */
+		if (entry->ih != &adev->irq.ih_soft &&
+		    amdgpu_gmc_filter_faults(adev, addr, entry->pasid,
+					     entry->timestamp))
+			return 1;
+
+		/* Delegate it to a different ring if the hardware hasn't
+		 * already done it.
+		 */
+		if (in_interrupt()) {
+			amdgpu_irq_delegate(adev, entry, 8);
+			return 1;
+		}
+
+		/* Try to handle the recoverable page faults by filling page
+		 * tables
+		 */
+		if (amdgpu_vm_handle_fault(adev, entry->pasid, addr))
+			return 1;
+	}
 
 	if (!printk_ratelimit())
 		return 0;