Merge tag 'dma-mapping-4.19-2' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "A few fixes for the fallout of being a little more pedantic about dma
  masks"

* tag 'dma-mapping-4.19-2' of git://git.infradead.org/users/hch/dma-mapping:
  of/platform: initialise AMBA default DMA masks
  sparc: set a default 32-bit dma mask for OF devices
  kernel/dma/direct: take DMA offset into account in dma_direct_supported

arch/sparc/kernel/of_device_32.c

@@ -9,6 +9,7 @@
 #include <linux/irq.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
+#include <linux/dma-mapping.h>
 #include <asm/leon.h>
 #include <asm/leon_amba.h>
 
@@ -381,6 +382,9 @@ static struct platform_device * __init scan_one_device(struct device_node *dp,
 	else
 		dev_set_name(&op->dev, "%08x", dp->phandle);
 
+	op->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	op->dev.dma_mask = &op->dev.coherent_dma_mask;
+
 	if (of_device_register(op)) {
 		printk("%s: Could not register of device.\n",
 		       dp->full_name);

arch/sparc/kernel/of_device_64.c

@@ -2,6 +2,7 @@
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
+#include <linux/dma-mapping.h>
 #include <linux/init.h>
 #include <linux/export.h>
 #include <linux/mod_devicetable.h>
@@ -675,6 +676,8 @@ static struct platform_device * __init scan_one_device(struct device_node *dp,
 		dev_set_name(&op->dev, "root");
 	else
 		dev_set_name(&op->dev, "%08x", dp->phandle);
+	op->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	op->dev.dma_mask = &op->dev.coherent_dma_mask;
 
 	if (of_device_register(op)) {
 		printk("%s: Could not register of device.\n",

drivers/of/platform.c

@@ -241,6 +241,10 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
 	if (!dev)
 		goto err_clear_flag;
 
+	/* AMBA devices only support a single DMA mask */
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+
 	/* setup generic device info */
 	dev->dev.of_node = of_node_get(node);
 	dev->dev.fwnode = &node->fwnode;

kernel/dma/direct.c

@@ -168,7 +168,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 int dma_direct_supported(struct device *dev, u64 mask)
 {
 #ifdef CONFIG_ZONE_DMA
-	if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
+	if (mask < phys_to_dma(dev, DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)))
 		return 0;
 #else
 	/*
@@ -177,7 +177,7 @@ int dma_direct_supported(struct device *dev, u64 mask)
 	 * memory, or by providing a ZONE_DMA32.  If neither is the case, the
 	 * architecture needs to use an IOMMU instead of the direct mapping.
 	 */
-	if (mask < DMA_BIT_MASK(32))
+	if (mask < phys_to_dma(dev, DMA_BIT_MASK(32)))
 		return 0;
 #endif
 	/*