coresight: tmc: Configure DMA mask appropriately

Before making any DMA API calls, the ETR driver should really be setting
its masks to ensure that DMA is possible. Especially since it can
address more than the 32-bit default mask set by the AMBA bus code.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-tmc.c

@@ -362,6 +362,13 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 		desc.type = CORESIGHT_DEV_TYPE_SINK;
 		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
 		desc.ops = &tmc_etr_cs_ops;
+		/*
+		 * ETR configuration uses a 40-bit AXI master in place of
+		 * the embedded SRAM of ETB/ETF.
+		 */
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40));
+		if (ret)
+			goto out;
 	} else {
 		desc.type = CORESIGHT_DEV_TYPE_LINKSINK;
 		desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_FIFO;