[PATCH 1/3] dma-mapping: Add devm_ interface for dma_map_single()

[PATCH 1/3] dma-mapping: Add devm_ interface for dma_map_single()

[Eli Billauer]

dmam_map_single() and dmam_unmap_single() are the managed counterparts
for the respective dma_* functions.

Note that dmam_map_single() returns zero on failure, and not a value to
be handled by dma_mapping_error(): The error check is done by
dmam_map_single() to avoid the registration of a mapping that failed.

Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
 Documentation/driver-model/devres.txt |    2 +
 drivers/base/dma-mapping.c            |   80 +++++++++++++++++++++++++++++++++
 include/linux/dma-mapping.h           |    5 ++-
 3 files changed, 86 insertions(+), 1 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index e1a2707..13b8be0 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -266,6 +266,8 @@ DMA
   dmam_declare_coherent_memory()
   dmam_pool_create()
   dmam_pool_destroy()
+  dmam_map_single()
+  dmam_unmap_single()
 
 PCI
   pcim_enable_device()	: after success, all PCI ops become managed
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 0ce39a3..db1c496 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -19,6 +19,7 @@ struct dma_devres {
 	size_t		size;
 	void		*vaddr;
 	dma_addr_t	dma_handle;
+	enum dma_data_direction direction;
 };
 
 static void dmam_coherent_release(struct device *dev, void *res)
@@ -267,3 +268,82 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 	return ret;
 }
 EXPORT_SYMBOL(dma_common_mmap);
+
+static int dmam_map_match(struct device *dev, void *res, void *match_data)
+{
+	struct dma_devres *this = res, *match = match_data;
+
+	if (this->dma_handle == match->dma_handle) {
+		WARN_ON(this->size != match->size ||
+			this->direction != match->direction);
+		return 1;
+	}
+	return 0;
+}
+
+static void dmam_map_single_release(struct device *dev, void *res)
+{
+	struct dma_devres *this = res;
+
+	dma_unmap_single(dev, this->dma_handle, this->size, this->direction);
+}
+
+/**
+ * dmam_map_single - Managed dma_map_single()
+ * @dev: Device to map DMA region for
+ * @ptr: Pointer to region
+ * @size: Size to map
+ * @direction: The mapping's direction
+ *
+ * Managed dma_map_single().  The region mapped using this
+ * function will be automatically unmapped on driver detach.
+ *
+ * RETURNS:
+ * The DMA handle of the mapped region upon success, 0 otherwise.
+ */
+dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
+			   enum dma_data_direction direction)
+
+{
+	struct dma_devres *dr;
+	dma_addr_t dma_handle;
+
+	dr = devres_alloc(dmam_map_single_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return 0;
+
+	dma_handle = dma_map_single(dev, ptr, size, direction);
+	if (dma_mapping_error(dev, dma_handle)) {
+		devres_free(dr);
+		return 0;
+	}
+
+	dr->vaddr = ptr;
+	dr->dma_handle = dma_handle;
+	dr->size = size;
+	dr->direction = direction;
+
+	devres_add(dev, dr);
+
+	return dma_handle;
+}
+EXPORT_SYMBOL(dmam_map_single);
+
+/**
+ * dmam_unmap_single - Managed dma_unmap_single()
+ * @dev: Device to map DMA region for
+ * @dma_handle: DMA handle of the region to unmap
+ * @size: Size to unmap
+ * @direction: The mapping's direction
+ *
+ * Managed dma_unmap_single().
+ */
+void dmam_unmap_single(struct device *dev, dma_addr_t dma_handle,
+		       size_t size, enum dma_data_direction direction)
+{
+	struct dma_devres match_data = { size, NULL, dma_handle, direction };
+
+	WARN_ON(devres_release(dev, dmam_map_single_release, dmam_map_match,
+			       &match_data));
+}
+EXPORT_SYMBOL(dmam_unmap_single);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index fd4aee2..cdb14a8 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -233,7 +233,10 @@ static inline void dmam_release_declared_memory(struct device *dev)
 {
 }
 #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
-
+dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
+			   enum dma_data_direction direction);
+void dmam_unmap_single(struct device *dev, dma_addr_t dma_handle,
+		       size_t size, enum dma_data_direction direction);
 #ifndef CONFIG_HAVE_DMA_ATTRS
 struct dma_attrs;
 
-- 
1.7.2.3

[PATCH 2/3] dma-mapping: Add devm_ interface for dma_map_single_attrs()

[Eli Billauer]

dmam_map_single_attrs() and dmam_unmap_single_attrs() replace the non-*_attrs
functions, which are implemented as defines instead.

The case of a non-NULL @attrs parameter has not been tested.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
 Documentation/driver-model/devres.txt    |    2 +
 drivers/base/dma-mapping.c               |   43 +++++++++++++++++++++--------
 include/asm-generic/dma-mapping-common.h |    2 +
 include/linux/dma-mapping.h              |   10 ++++---
 4 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 13b8be0..2112a00 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -268,6 +268,8 @@ DMA
   dmam_pool_destroy()
   dmam_map_single()
   dmam_unmap_single()
+  dmam_map_single_attrs()
+  dmam_unmap_single_attrs()
 
 PCI
   pcim_enable_device()	: after success, all PCI ops become managed
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index db1c496..4e80db1 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <asm-generic/dma-coherent.h>
+#include <linux/slab.h>
 
 /*
  * Managed DMA API
@@ -20,6 +21,7 @@ struct dma_devres {
 	void		*vaddr;
 	dma_addr_t	dma_handle;
 	enum dma_data_direction direction;
+	struct dma_attrs *attrs;
 };
 
 static void dmam_coherent_release(struct device *dev, void *res)
@@ -285,24 +287,29 @@ static void dmam_map_single_release(struct device *dev, void *res)
 {
 	struct dma_devres *this = res;
 
-	dma_unmap_single(dev, this->dma_handle, this->size, this->direction);
+	dma_unmap_single_attrs(dev, this->dma_handle, this->size,
+			       this->direction, this->attrs);
+
+	kfree(this->attrs);
 }
 
 /**
- * dmam_map_single - Managed dma_map_single()
+ * dmam_map_single_attrs - Managed dma_map_single_attrs()
  * @dev: Device to map DMA region for
  * @ptr: Pointer to region
  * @size: Size to map
  * @direction: The mapping's direction
+ * @attrs: Attributes associated with the DMA mapping
  *
- * Managed dma_map_single().  The region mapped using this
+ * Managed dma_map_single_attrs().  The region mapped using this
  * function will be automatically unmapped on driver detach.
  *
  * RETURNS:
  * The DMA handle of the mapped region upon success, 0 otherwise.
  */
-dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
-			   enum dma_data_direction direction)
+dma_addr_t dmam_map_single_attrs(struct device *dev, void *ptr, size_t size,
+				 enum dma_data_direction direction,
+				 struct dma_attrs *attrs)
 
 {
 	struct dma_devres *dr;
@@ -312,8 +319,18 @@ dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
 	if (!dr)
 		return 0;
 
-	dma_handle = dma_map_single(dev, ptr, size, direction);
+	if (attrs) {
+		dr->attrs = kmemdup(attrs, sizeof(*attrs), GFP_KERNEL);
+		if (!dr->attrs) {
+			devres_free(dr);
+			return 0;
+		}
+	} else
+		dr->attrs = NULL;
+
+	dma_handle = dma_map_single_attrs(dev, ptr, size, direction, attrs);
 	if (dma_mapping_error(dev, dma_handle)) {
+		kfree(dr->attrs);
 		devres_free(dr);
 		return 0;
 	}
@@ -327,23 +344,25 @@ dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
 
 	return dma_handle;
 }
-EXPORT_SYMBOL(dmam_map_single);
+EXPORT_SYMBOL(dmam_map_single_attrs);
 
 /**
- * dmam_unmap_single - Managed dma_unmap_single()
+ * dmam_unmap_single_attrs - Managed dma_unmap_single_attrs()
  * @dev: Device to map DMA region for
  * @dma_handle: DMA handle of the region to unmap
  * @size: Size to unmap
  * @direction: The mapping's direction
+ * @attrs: Attributes associated with the DMA mapping.
  *
- * Managed dma_unmap_single().
+ * Managed dma_unmap_single_attrs().
  */
-void dmam_unmap_single(struct device *dev, dma_addr_t dma_handle,
-		       size_t size, enum dma_data_direction direction)
+void dmam_unmap_single_attrs(struct device *dev, dma_addr_t dma_handle,
+			     size_t size, enum dma_data_direction direction,
+			     struct dma_attrs *attrs)
 {
 	struct dma_devres match_data = { size, NULL, dma_handle, direction };
 
 	WARN_ON(devres_release(dev, dmam_map_single_release, dmam_map_match,
 			       &match_data));
 }
-EXPORT_SYMBOL(dmam_unmap_single);
+EXPORT_SYMBOL(dmam_unmap_single_attrs);
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index de8bf89..aaa7c68 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -175,6 +175,8 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, NULL)
 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL)
 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)
+#define dmam_map_single(d, a, s, r) dmam_map_single_attrs(d, a, s, r, NULL)
+#define dmam_unmap_single(d, a, s, r) dmam_unmap_single_attrs(d, a, s, r, NULL)
 
 extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 			   void *cpu_addr, dma_addr_t dma_addr, size_t size);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index cdb14a8..ba2a403 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -233,10 +233,12 @@ static inline void dmam_release_declared_memory(struct device *dev)
 {
 }
 #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
-dma_addr_t dmam_map_single(struct device *dev, void *ptr, size_t size,
-			   enum dma_data_direction direction);
-void dmam_unmap_single(struct device *dev, dma_addr_t dma_handle,
-		       size_t size, enum dma_data_direction direction);
+dma_addr_t dmam_map_single_attrs(struct device *dev, void *ptr, size_t size,
+				 enum dma_data_direction direction,
+				 struct dma_attrs *attrs);
+void dmam_unmap_single_attrs(struct device *dev, dma_addr_t dma_handle,
+			     size_t size, enum dma_data_direction direction,
+			     struct dma_attrs *attrs);
 #ifndef CONFIG_HAVE_DMA_ATTRS
 struct dma_attrs;
 
-- 
1.7.2.3

[PATCH 3/3] dma-mapping: pci: Add devm_ interface for pci_map_single

[Eli Billauer]

Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
 Documentation/driver-model/devres.txt |    2 ++
 include/asm-generic/pci-dma-compat.h  |   17 +++++++++++++++++
 2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 2112a00..fea2c69 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -274,6 +274,8 @@ DMA
 PCI
   pcim_enable_device()	: after success, all PCI ops become managed
   pcim_pin_device()	: keep PCI device enabled after release
+  pcim_map_single()
+  pcim_unmap_single()
 
 IOMAP
   devm_ioport_map()
diff --git a/include/asm-generic/pci-dma-compat.h b/include/asm-generic/pci-dma-compat.h
index 1437b7d..444e598 100644
--- a/include/asm-generic/pci-dma-compat.h
+++ b/include/asm-generic/pci-dma-compat.h
@@ -113,4 +113,21 @@ static inline int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 }
 #endif
 
+/*
+ * Managed DMA API
+ */
+
+static inline dma_addr_t
+pcim_map_single(struct pci_dev *hwdev, void *ptr, size_t size, int direction)
+{
+	return dmam_map_single(hwdev == NULL ? NULL : &hwdev->dev, ptr, size, (enum dma_data_direction)direction);
+}
+
+static inline void
+pcim_unmap_single(struct pci_dev *hwdev, dma_addr_t dma_addr,
+		 size_t size, int direction)
+{
+	dmam_unmap_single(hwdev == NULL ? NULL : &hwdev->dev, dma_addr, size, (enum dma_data_direction)direction);
+}
+
 #endif
-- 
1.7.2.3