---

yaml
---
r: 347495
b: refs/heads/master
c: eb9c952
h: refs/heads/master
i:
  347493: 851cae0
  347491: 785a2e9
  347487: 46e1a55
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a0157573041403e7507a6f3f32279fc14ff5c02e
+refs/heads/master: eb9c95271eafb62f7024547016ad00636c1425c1

trunk/Documentation/DMA-API-HOWTO.txt

@@ -468,46 +468,11 @@ To map a single region, you do:
 	size_t size = buffer->len;
 
 	dma_handle = dma_map_single(dev, addr, size, direction);
-	if (dma_mapping_error(dma_handle)) {
-		/*
-		 * reduce current DMA mapping usage,
-		 * delay and try again later or
-		 * reset driver.
-		 */
-		goto map_error_handling;
-	}
 
 and to unmap it:
 
 	dma_unmap_single(dev, dma_handle, size, direction);
 
-You should call dma_mapping_error() as dma_map_single() could fail and return
-error. Not all dma implementations support dma_mapping_error() interface.
-However, it is a good practice to call dma_mapping_error() interface, which
-will invoke the generic mapping error check interface. Doing so will ensure
-that the mapping code will work correctly on all dma implementations without
-any dependency on the specifics of the underlying implementation. Using the
-returned address without checking for errors could result in failures ranging
-from panics to silent data corruption. Couple of example of incorrect ways to
-check for errors that make assumptions about the underlying dma implementation
-are as follows and these are applicable to dma_map_page() as well.
-
-Incorrect example 1:
-	dma_addr_t dma_handle;
-
-	dma_handle = dma_map_single(dev, addr, size, direction);
-	if ((dma_handle & 0xffff != 0) || (dma_handle >= 0x1000000)) {
-		goto map_error;
-	}
-
-Incorrect example 2:
-	dma_addr_t dma_handle;
-
-	dma_handle = dma_map_single(dev, addr, size, direction);
-	if (dma_handle == DMA_ERROR_CODE) {
-		goto map_error;
-	}
-
 You should call dma_unmap_single when the DMA activity is finished, e.g.
 from the interrupt which told you that the DMA transfer is done.
 
@@ -524,27 +489,13 @@ Specifically:
 	size_t size = buffer->len;
 
 	dma_handle = dma_map_page(dev, page, offset, size, direction);
-	if (dma_mapping_error(dma_handle)) {
-		/*
-		 * reduce current DMA mapping usage,
-		 * delay and try again later or
-		 * reset driver.
-		 */
-		goto map_error_handling;
-	}
 
 	...
 
 	dma_unmap_page(dev, dma_handle, size, direction);
 
 Here, "offset" means byte offset within the given page.
 
-You should call dma_mapping_error() as dma_map_page() could fail and return
-error as outlined under the dma_map_single() discussion.
-
-You should call dma_unmap_page when the DMA activity is finished, e.g.
-from the interrupt which told you that the DMA transfer is done.
-
 With scatterlists, you map a region gathered from several regions by:
 
 	int i, count = dma_map_sg(dev, sglist, nents, direction);
@@ -627,14 +578,6 @@ to use the dma_sync_*() interfaces.
 		dma_addr_t mapping;
 
 		mapping = dma_map_single(cp->dev, buffer, len, DMA_FROM_DEVICE);
-		if (dma_mapping_error(dma_handle)) {
-			/*
-			 * reduce current DMA mapping usage,
-			 * delay and try again later or
-			 * reset driver.
-			 */
-			goto map_error_handling;
-		}
 
 		cp->rx_buf = buffer;
 		cp->rx_len = len;
@@ -715,75 +658,6 @@ failure can be determined by:
 		 * delay and try again later or
 		 * reset driver.
 		 */
-		goto map_error_handling;
-	}
-
-- unmap pages that are already mapped, when mapping error occurs in the middle
-  of a multiple page mapping attempt. These example are applicable to
-  dma_map_page() as well.
-
-Example 1:
-	dma_addr_t dma_handle1;
-	dma_addr_t dma_handle2;
-
-	dma_handle1 = dma_map_single(dev, addr, size, direction);
-	if (dma_mapping_error(dev, dma_handle1)) {
-		/*
-		 * reduce current DMA mapping usage,
-		 * delay and try again later or
-		 * reset driver.
-		 */
-		goto map_error_handling1;
-	}
-	dma_handle2 = dma_map_single(dev, addr, size, direction);
-	if (dma_mapping_error(dev, dma_handle2)) {
-		/*
-		 * reduce current DMA mapping usage,
-		 * delay and try again later or
-		 * reset driver.
-		 */
-		goto map_error_handling2;
-	}
-
-	...
-
-	map_error_handling2:
-		dma_unmap_single(dma_handle1);
-	map_error_handling1:
-
-Example 2: (if buffers are allocated a loop, unmap all mapped buffers when
-	    mapping error is detected in the middle)
-
-	dma_addr_t dma_addr;
-	dma_addr_t array[DMA_BUFFERS];
-	int save_index = 0;
-
-	for (i = 0; i < DMA_BUFFERS; i++) {
-
-		...
-
-		dma_addr = dma_map_single(dev, addr, size, direction);
-		if (dma_mapping_error(dev, dma_addr)) {
-			/*
-			 * reduce current DMA mapping usage,
-			 * delay and try again later or
-			 * reset driver.
-			 */
-			goto map_error_handling;
-		}
-		array[i].dma_addr = dma_addr;
-		save_index++;
-	}
-
-	...
-
-	map_error_handling:
-
-	for (i = 0; i < save_index; i++) {
-
-		...
-
-		dma_unmap_single(array[i].dma_addr);
 	}
 
 Networking drivers must call dev_kfree_skb to free the socket buffer

trunk/Documentation/DMA-API.txt

@@ -678,15 +678,3 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
 of preallocated entries is defined per architecture. If it is too low for you
 boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
 architectural default.
-
-void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
-
-dma-debug interface debug_dma_mapping_error() to debug drivers that fail
-to check dma mapping errors on addresses returned by dma_map_single() and
-dma_map_page() interfaces. This interface clears a flag set by
-debug_dma_map_page() to indicate that dma_mapping_error() has been called by
-the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
-this flag is still set, prints warning message that includes call trace that
-leads up to the unmap. This interface can be called from dma_mapping_error()
-routines to enable dma mapping error check debugging.
-

trunk/arch/arm/include/asm/dma-mapping.h

@@ -91,7 +91,6 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
-	debug_dma_mapping_error(dev, dma_addr);
 	return dma_addr == DMA_ERROR_CODE;
 }
 

trunk/arch/arm64/include/asm/dma-mapping.h

@@ -50,7 +50,6 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dev_addr)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
-	debug_dma_mapping_error(dev, dev_addr);
 	return ops->mapping_error(dev, dev_addr);
 }
 

trunk/arch/c6x/include/asm/dma-mapping.h

@@ -32,7 +32,6 @@ static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
-	debug_dma_mapping_error(dev, dma_addr);
 	return dma_addr == ~0;
 }
 

trunk/arch/ia64/include/asm/dma-mapping.h

@@ -58,7 +58,6 @@ static inline void dma_free_attrs(struct device *dev, size_t size,
 static inline int dma_mapping_error(struct device *dev, dma_addr_t daddr)
 {
 	struct dma_map_ops *ops = platform_dma_get_ops(dev);
-	debug_dma_mapping_error(dev, daddr);
 	return ops->mapping_error(dev, daddr);
 }
 

trunk/arch/microblaze/include/asm/dma-mapping.h

@@ -114,8 +114,6 @@ static inline void __dma_sync(unsigned long paddr,
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
-
-	debug_dma_mapping_error(dev, dma_addr);
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 

trunk/arch/mips/include/asm/dma-mapping.h

@@ -40,8 +40,6 @@ static inline int dma_supported(struct device *dev, u64 mask)
 static inline int dma_mapping_error(struct device *dev, u64 mask)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
-
-	debug_dma_mapping_error(dev, mask);
 	return ops->mapping_error(dev, mask);
 }
 

trunk/arch/powerpc/include/asm/dma-mapping.h

@@ -172,7 +172,6 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
-	debug_dma_mapping_error(dev, dma_addr);
 	if (dma_ops->mapping_error)
 		return dma_ops->mapping_error(dev, dma_addr);
 

trunk/arch/sh/include/asm/dma-mapping.h

@@ -46,7 +46,6 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
 
-	debug_dma_mapping_error(dev, dma_addr);
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 

trunk/arch/sparc/include/asm/dma-mapping.h

@@ -59,7 +59,6 @@ static inline void dma_free_attrs(struct device *dev, size_t size,
 
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
-	debug_dma_mapping_error(dev, dma_addr);
 	return (dma_addr == DMA_ERROR_CODE);
 }
 

trunk/arch/tile/include/asm/dma-mapping.h

@@ -72,7 +72,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 static inline int
 dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
-	debug_dma_mapping_error(dev, dma_addr);
 	return get_dma_ops(dev)->mapping_error(dev, dma_addr);
 }
 

trunk/arch/x86/include/asm/dma-mapping.h

@@ -47,7 +47,6 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
-	debug_dma_mapping_error(dev, dma_addr);
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 

trunk/drivers/iommu/amd_iommu.c

@@ -276,39 +276,32 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to)
 
 #define REQ_ACS_FLAGS	(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
 
-static int iommu_init_device(struct device *dev)
+static int init_iommu_group(struct device *dev)
 {
-	struct pci_dev *dma_pdev = NULL, *pdev = to_pci_dev(dev);
 	struct iommu_dev_data *dev_data;
 	struct iommu_group *group;
-	u16 alias;
+	struct pci_dev *dma_pdev = NULL;
 	int ret;
 
-	if (dev->archdata.iommu)
+	group = iommu_group_get(dev);
+	if (group) {
+		iommu_group_put(group);
 		return 0;
+	}
 
 	dev_data = find_dev_data(get_device_id(dev));
 	if (!dev_data)
 		return -ENOMEM;
 
-	alias = amd_iommu_alias_table[dev_data->devid];
-	if (alias != dev_data->devid) {
-		struct iommu_dev_data *alias_data;
-
-		alias_data = find_dev_data(alias);
-		if (alias_data == NULL) {
-			pr_err("AMD-Vi: Warning: Unhandled device %s\n",
-					dev_name(dev));
-			free_dev_data(dev_data);
-			return -ENOTSUPP;
-		}
-		dev_data->alias_data = alias_data;
+	if (dev_data->alias_data) {
+		u16 alias;
 
+		alias = amd_iommu_alias_table[dev_data->devid];
 		dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
 	}
 
-	if (dma_pdev == NULL)
-		dma_pdev = pci_dev_get(pdev);
+	if (!dma_pdev)
+		dma_pdev = pci_dev_get(to_pci_dev(dev));
 
 	/* Account for quirked devices */
 	swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
@@ -358,6 +351,38 @@ static int iommu_init_device(struct device *dev)
 
 	iommu_group_put(group);
 
+	return ret;
+}
+
+static int iommu_init_device(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct iommu_dev_data *dev_data;
+	u16 alias;
+	int ret;
+
+	if (dev->archdata.iommu)
+		return 0;
+
+	dev_data = find_dev_data(get_device_id(dev));
+	if (!dev_data)
+		return -ENOMEM;
+
+	alias = amd_iommu_alias_table[dev_data->devid];
+	if (alias != dev_data->devid) {
+		struct iommu_dev_data *alias_data;
+
+		alias_data = find_dev_data(alias);
+		if (alias_data == NULL) {
+			pr_err("AMD-Vi: Warning: Unhandled device %s\n",
+					dev_name(dev));
+			free_dev_data(dev_data);
+			return -ENOTSUPP;
+		}
+		dev_data->alias_data = alias_data;
+	}
+
+	ret = init_iommu_group(dev);
 	if (ret)
 		return ret;
 

trunk/include/linux/dma-debug.h

@@ -39,8 +39,6 @@ extern void debug_dma_map_page(struct device *dev, struct page *page,
 			       int direction, dma_addr_t dma_addr,
 			       bool map_single);
 
-extern void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
-
 extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 				 size_t size, int direction, bool map_single);
 
@@ -107,11 +105,6 @@ static inline void debug_dma_map_page(struct device *dev, struct page *page,
 {
 }
 
-static inline void debug_dma_mapping_error(struct device *dev,
-					  dma_addr_t dma_addr)
-{
-}
-
 static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
 					size_t size, int direction,
 					bool map_single)