drm/etnaviv: split out and optimize MMU fault dumping

Split out the fault dumping, as this will get more complex in the future.
Also there is no need to read and dump the fault address from MMUs that
didn't signal a fault.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1297,9 +1297,22 @@ static void sync_point_worker(struct work_struct *work)
 	etnaviv_gpu_start_fe(gpu, addr + 2, 2);
 }
 
-/*
- * Init/Cleanup:
- */
+static void dump_mmu_fault(struct etnaviv_gpu *gpu)
+{
+	u32 status = gpu_read(gpu, VIVS_MMUv2_STATUS);
+	int i;
+
+	dev_err_ratelimited(gpu->dev, "MMU fault status 0x%08x\n", status);
+
+	for (i = 0; i < 4; i++) {
+		if (!(status & (VIVS_MMUv2_STATUS_EXCEPTION0__MASK << (i * 4))))
+			continue;
+
+		dev_err_ratelimited(gpu->dev, "MMU %d fault addr 0x%08x\n", i,
+				gpu_read(gpu, VIVS_MMUv2_EXCEPTION_ADDR(i)));
+	}
+}
+
 static irqreturn_t irq_handler(int irq, void *data)
 {
 	struct etnaviv_gpu *gpu = data;
@@ -1320,17 +1333,7 @@ static irqreturn_t irq_handler(int irq, void *data)
 		}
 
 		if (intr & VIVS_HI_INTR_ACKNOWLEDGE_MMU_EXCEPTION) {
-			int i;
-
-			dev_err_ratelimited(gpu->dev,
-				"MMU fault status 0x%08x\n",
-				gpu_read(gpu, VIVS_MMUv2_STATUS));
-			for (i = 0; i < 4; i++) {
-				dev_err_ratelimited(gpu->dev,
-					"MMU %d fault addr 0x%08x\n",
-					i, gpu_read(gpu,
-					VIVS_MMUv2_EXCEPTION_ADDR(i)));
-			}
+			dump_mmu_fault(gpu);
 			intr &= ~VIVS_HI_INTR_ACKNOWLEDGE_MMU_EXCEPTION;
 		}