Web lists-archives.com

[PATCH v2 13/31] DMA-API.txt: standardize document format




Each text file under Documentation follows a different
format. Some doesn't even have titles!

Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:

- Fix some title marks to match ReST;
- use :Author: for author name;
- foo_ is an hyperlink. Get rid of it;
- Mark literal blocks as such;
- Use tables on some places that are almost using the
  table format.

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
 Documentation/DMA-API.txt | 576 ++++++++++++++++++++++++++--------------------
 1 file changed, 327 insertions(+), 249 deletions(-)

diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 71200dfa0922..45b29326d719 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -1,7 +1,8 @@
-               Dynamic DMA mapping using the generic device
-               ============================================
+============================================
+Dynamic DMA mapping using the generic device
+============================================
 
-        James E.J. Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
+:Author: James E.J. Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
 
 This document describes the DMA API.  For a more gentle introduction
 of the API (and actual examples), see Documentation/DMA-API-HOWTO.txt.
@@ -12,10 +13,10 @@ machines.  Unless you know that your driver absolutely has to support
 non-consistent platforms (this is usually only legacy platforms) you
 should only use the API described in part I.
 
-Part I - dma_ API
--------------------------------------
+Part I - dma_API
+----------------
 
-To get the dma_ API, you must #include <linux/dma-mapping.h>.  This
+To get the dma_API, you must #include <linux/dma-mapping.h>.  This
 provides dma_addr_t and the interfaces described below.
 
 A dma_addr_t can hold any valid DMA address for the platform.  It can be
@@ -26,9 +27,11 @@ address space and the DMA address space.
 Part Ia - Using large DMA-coherent buffers
 ------------------------------------------
 
-void *
-dma_alloc_coherent(struct device *dev, size_t size,
-			     dma_addr_t *dma_handle, gfp_t flag)
+::
+
+	void *
+	dma_alloc_coherent(struct device *dev, size_t size,
+			   dma_addr_t *dma_handle, gfp_t flag)
 
 Consistent memory is memory for which a write by either the device or
 the processor can immediately be read by the processor or device
@@ -51,20 +54,24 @@ consolidate your requests for consistent memory as much as possible.
 The simplest way to do that is to use the dma_pool calls (see below).
 
 The flag parameter (dma_alloc_coherent() only) allows the caller to
-specify the GFP_ flags (see kmalloc()) for the allocation (the
+specify the ``GFP_`` flags (see kmalloc()) for the allocation (the
 implementation may choose to ignore flags that affect the location of
 the returned memory, like GFP_DMA).
 
-void *
-dma_zalloc_coherent(struct device *dev, size_t size,
-			     dma_addr_t *dma_handle, gfp_t flag)
+::
+
+	void *
+	dma_zalloc_coherent(struct device *dev, size_t size,
+			    dma_addr_t *dma_handle, gfp_t flag)
 
 Wraps dma_alloc_coherent() and also zeroes the returned memory if the
 allocation attempt succeeded.
 
-void
-dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
-			   dma_addr_t dma_handle)
+::
+
+	void
+	dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
+			  dma_addr_t dma_handle)
 
 Free a region of consistent memory you previously allocated.  dev,
 size and dma_handle must all be the same as those passed into
@@ -78,7 +85,7 @@ may only be called with IRQs enabled.
 Part Ib - Using small DMA-coherent buffers
 ------------------------------------------
 
-To get this part of the dma_ API, you must #include <linux/dmapool.h>
+To get this part of the dma_API, you must #include <linux/dmapool.h>
 
 Many drivers need lots of small DMA-coherent memory regions for DMA
 descriptors or I/O buffers.  Rather than allocating in units of a page
@@ -88,6 +95,8 @@ not __get_free_pages().  Also, they understand common hardware constraints
 for alignment, like queue heads needing to be aligned on N-byte boundaries.
 
 
+::
+
 	struct dma_pool *
 	dma_pool_create(const char *name, struct device *dev,
 			size_t size, size_t align, size_t alloc);
@@ -103,16 +112,21 @@ in bytes, and must be a power of two).  If your device has no boundary
 crossing restrictions, pass 0 for alloc; passing 4096 says memory allocated
 from this pool must not cross 4KByte boundaries.
 
+::
 
-	void *dma_pool_zalloc(struct dma_pool *pool, gfp_t mem_flags,
-			      dma_addr_t *handle)
+	void *
+	dma_pool_zalloc(struct dma_pool *pool, gfp_t mem_flags,
+		        dma_addr_t *handle)
 
 Wraps dma_pool_alloc() and also zeroes the returned memory if the
 allocation attempt succeeded.
 
 
-	void *dma_pool_alloc(struct dma_pool *pool, gfp_t gfp_flags,
-			dma_addr_t *dma_handle);
+::
+
+	void *
+	dma_pool_alloc(struct dma_pool *pool, gfp_t gfp_flags,
+		       dma_addr_t *dma_handle);
 
 This allocates memory from the pool; the returned memory will meet the
 size and alignment requirements specified at creation time.  Pass
@@ -122,16 +136,20 @@ blocking.  Like dma_alloc_coherent(), this returns two values:  an
 address usable by the CPU, and the DMA address usable by the pool's
 device.
 
+::
 
-	void dma_pool_free(struct dma_pool *pool, void *vaddr,
-			dma_addr_t addr);
+	void
+	dma_pool_free(struct dma_pool *pool, void *vaddr,
+		      dma_addr_t addr);
 
 This puts memory back into the pool.  The pool is what was passed to
 dma_pool_alloc(); the CPU (vaddr) and DMA addresses are what
 were returned when that routine allocated the memory being freed.
 
+::
 
-	void dma_pool_destroy(struct dma_pool *pool);
+	void
+	dma_pool_destroy(struct dma_pool *pool);
 
 dma_pool_destroy() frees the resources of the pool.  It must be
 called in a context which can sleep.  Make sure you've freed all allocated
@@ -141,32 +159,40 @@ memory back to the pool before you destroy it.
 Part Ic - DMA addressing limitations
 ------------------------------------
 
-int
-dma_set_mask_and_coherent(struct device *dev, u64 mask)
+::
+
+	int
+	dma_set_mask_and_coherent(struct device *dev, u64 mask)
 
 Checks to see if the mask is possible and updates the device
 streaming and coherent DMA mask parameters if it is.
 
 Returns: 0 if successful and a negative error if not.
 
-int
-dma_set_mask(struct device *dev, u64 mask)
+::
+
+	int
+	dma_set_mask(struct device *dev, u64 mask)
 
 Checks to see if the mask is possible and updates the device
 parameters if it is.
 
 Returns: 0 if successful and a negative error if not.
 
-int
-dma_set_coherent_mask(struct device *dev, u64 mask)
+::
+
+	int
+	dma_set_coherent_mask(struct device *dev, u64 mask)
 
 Checks to see if the mask is possible and updates the device
 parameters if it is.
 
 Returns: 0 if successful and a negative error if not.
 
-u64
-dma_get_required_mask(struct device *dev)
+::
+
+	u64
+	dma_get_required_mask(struct device *dev)
 
 This API returns the mask that the platform requires to
 operate efficiently.  Usually this means the returned mask
@@ -182,94 +208,107 @@ call to set the mask to the value returned.
 Part Id - Streaming DMA mappings
 --------------------------------
 
-dma_addr_t
-dma_map_single(struct device *dev, void *cpu_addr, size_t size,
-		      enum dma_data_direction direction)
+::
+
+	dma_addr_t
+	dma_map_single(struct device *dev, void *cpu_addr, size_t size,
+		       enum dma_data_direction direction)
 
 Maps a piece of processor virtual memory so it can be accessed by the
 device and returns the DMA address of the memory.
 
 The direction for both APIs may be converted freely by casting.
-However the dma_ API uses a strongly typed enumerator for its
+However the dma_API uses a strongly typed enumerator for its
 direction:
 
+======================= =============================================
 DMA_NONE		no direction (used for debugging)
 DMA_TO_DEVICE		data is going from the memory to the device
 DMA_FROM_DEVICE		data is coming from the device to the memory
 DMA_BIDIRECTIONAL	direction isn't known
+======================= =============================================
 
-Notes:  Not all memory regions in a machine can be mapped by this API.
-Further, contiguous kernel virtual space may not be contiguous as
-physical memory.  Since this API does not provide any scatter/gather
-capability, it will fail if the user tries to map a non-physically
-contiguous piece of memory.  For this reason, memory to be mapped by
-this API should be obtained from sources which guarantee it to be
-physically contiguous (like kmalloc).
-
-Further, the DMA address of the memory must be within the
-dma_mask of the device (the dma_mask is a bit mask of the
-addressable region for the device, i.e., if the DMA address of
-the memory ANDed with the dma_mask is still equal to the DMA
-address, then the device can perform DMA to the memory).  To
-ensure that the memory allocated by kmalloc is within the dma_mask,
-the driver may specify various platform-dependent flags to restrict
-the DMA address range of the allocation (e.g., on x86, GFP_DMA
-guarantees to be within the first 16MB of available DMA addresses,
-as required by ISA devices).
-
-Note also that the above constraints on physical contiguity and
-dma_mask may not apply if the platform has an IOMMU (a device which
-maps an I/O DMA address to a physical memory address).  However, to be
-portable, device driver writers may *not* assume that such an IOMMU
-exists.
-
-Warnings:  Memory coherency operates at a granularity called the cache
-line width.  In order for memory mapped by this API to operate
-correctly, the mapped region must begin exactly on a cache line
-boundary and end exactly on one (to prevent two separately mapped
-regions from sharing a single cache line).  Since the cache line size
-may not be known at compile time, the API will not enforce this
-requirement.  Therefore, it is recommended that driver writers who
-don't take special care to determine the cache line size at run time
-only map virtual regions that begin and end on page boundaries (which
-are guaranteed also to be cache line boundaries).
-
-DMA_TO_DEVICE synchronisation must be done after the last modification
-of the memory region by the software and before it is handed off to
-the device.  Once this primitive is used, memory covered by this
-primitive should be treated as read-only by the device.  If the device
-may write to it at any point, it should be DMA_BIDIRECTIONAL (see
-below).
-
-DMA_FROM_DEVICE synchronisation must be done before the driver
-accesses data that may be changed by the device.  This memory should
-be treated as read-only by the driver.  If the driver needs to write
-to it at any point, it should be DMA_BIDIRECTIONAL (see below).
-
-DMA_BIDIRECTIONAL requires special handling: it means that the driver
-isn't sure if the memory was modified before being handed off to the
-device and also isn't sure if the device will also modify it.  Thus,
-you must always sync bidirectional memory twice: once before the
-memory is handed off to the device (to make sure all memory changes
-are flushed from the processor) and once before the data may be
-accessed after being used by the device (to make sure any processor
-cache lines are updated with data that the device may have changed).
-
-void
-dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
-		 enum dma_data_direction direction)
+.. note::
+
+	Not all memory regions in a machine can be mapped by this API.
+	Further, contiguous kernel virtual space may not be contiguous as
+	physical memory.  Since this API does not provide any scatter/gather
+	capability, it will fail if the user tries to map a non-physically
+	contiguous piece of memory.  For this reason, memory to be mapped by
+	this API should be obtained from sources which guarantee it to be
+	physically contiguous (like kmalloc).
+
+	Further, the DMA address of the memory must be within the
+	dma_mask of the device (the dma_mask is a bit mask of the
+	addressable region for the device, i.e., if the DMA address of
+	the memory ANDed with the dma_mask is still equal to the DMA
+	address, then the device can perform DMA to the memory).  To
+	ensure that the memory allocated by kmalloc is within the dma_mask,
+	the driver may specify various platform-dependent flags to restrict
+	the DMA address range of the allocation (e.g., on x86, GFP_DMA
+	guarantees to be within the first 16MB of available DMA addresses,
+	as required by ISA devices).
+
+	Note also that the above constraints on physical contiguity and
+	dma_mask may not apply if the platform has an IOMMU (a device which
+	maps an I/O DMA address to a physical memory address).  However, to be
+	portable, device driver writers may *not* assume that such an IOMMU
+	exists.
+
+.. warning::
+
+	Memory coherency operates at a granularity called the cache
+	line width.  In order for memory mapped by this API to operate
+	correctly, the mapped region must begin exactly on a cache line
+	boundary and end exactly on one (to prevent two separately mapped
+	regions from sharing a single cache line).  Since the cache line size
+	may not be known at compile time, the API will not enforce this
+	requirement.  Therefore, it is recommended that driver writers who
+	don't take special care to determine the cache line size at run time
+	only map virtual regions that begin and end on page boundaries (which
+	are guaranteed also to be cache line boundaries).
+
+	DMA_TO_DEVICE synchronisation must be done after the last modification
+	of the memory region by the software and before it is handed off to
+	the device.  Once this primitive is used, memory covered by this
+	primitive should be treated as read-only by the device.  If the device
+	may write to it at any point, it should be DMA_BIDIRECTIONAL (see
+	below).
+
+	DMA_FROM_DEVICE synchronisation must be done before the driver
+	accesses data that may be changed by the device.  This memory should
+	be treated as read-only by the driver.  If the driver needs to write
+	to it at any point, it should be DMA_BIDIRECTIONAL (see below).
+
+	DMA_BIDIRECTIONAL requires special handling: it means that the driver
+	isn't sure if the memory was modified before being handed off to the
+	device and also isn't sure if the device will also modify it.  Thus,
+	you must always sync bidirectional memory twice: once before the
+	memory is handed off to the device (to make sure all memory changes
+	are flushed from the processor) and once before the data may be
+	accessed after being used by the device (to make sure any processor
+	cache lines are updated with data that the device may have changed).
+
+::
+
+	void
+	dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+			 enum dma_data_direction direction)
 
 Unmaps the region previously mapped.  All the parameters passed in
 must be identical to those passed in (and returned) by the mapping
 API.
 
-dma_addr_t
-dma_map_page(struct device *dev, struct page *page,
-		    unsigned long offset, size_t size,
-		    enum dma_data_direction direction)
-void
-dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
-	       enum dma_data_direction direction)
+::
+
+	dma_addr_t
+	dma_map_page(struct device *dev, struct page *page,
+		     unsigned long offset, size_t size,
+		     enum dma_data_direction direction)
+
+	void
+	dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+		       enum dma_data_direction direction)
 
 API for mapping and unmapping for pages.  All the notes and warnings
 for the other mapping APIs apply here.  Also, although the <offset>
@@ -277,20 +316,24 @@ and <size> parameters are provided to do partial page mapping, it is
 recommended that you never use these unless you really know what the
 cache width is.
 
-dma_addr_t
-dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
-		 enum dma_data_direction dir, unsigned long attrs)
+::
 
-void
-dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
-		   enum dma_data_direction dir, unsigned long attrs)
+	dma_addr_t
+	dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
+			 enum dma_data_direction dir, unsigned long attrs)
+
+	void
+	dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
+			   enum dma_data_direction dir, unsigned long attrs)
 
 API for mapping and unmapping for MMIO resources. All the notes and
 warnings for the other mapping APIs apply here. The API should only be
 used to map device MMIO resources, mapping of RAM is not permitted.
 
-int
-dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+::
+
+	int
+	dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 
 In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
 will fail to create a mapping. A driver can check for these errors by testing
@@ -298,9 +341,11 @@ the returned DMA address with dma_mapping_error(). A non-zero return value
 means the mapping could not be created and the driver should take appropriate
 action (e.g. reduce current DMA mapping usage or delay and try again later).
 
+::
+
 	int
 	dma_map_sg(struct device *dev, struct scatterlist *sg,
-		int nents, enum dma_data_direction direction)
+		   int nents, enum dma_data_direction direction)
 
 Returns: the number of DMA address segments mapped (this may be shorter
 than <nents> passed in if some elements of the scatter/gather list are
@@ -316,7 +361,7 @@ critical that the driver do something, in the case of a block driver
 aborting the request or even oopsing is better than doing nothing and
 corrupting the filesystem.
 
-With scatterlists, you use the resulting mapping like this:
+With scatterlists, you use the resulting mapping like this::
 
 	int i, count = dma_map_sg(dev, sglist, nents, direction);
 	struct scatterlist *sg;
@@ -337,9 +382,11 @@ Then you should loop count times (note: this can be less than nents times)
 and use sg_dma_address() and sg_dma_len() macros where you previously
 accessed sg->address and sg->length as shown above.
 
+::
+
 	void
 	dma_unmap_sg(struct device *dev, struct scatterlist *sg,
-		int nents, enum dma_data_direction direction)
+		     int nents, enum dma_data_direction direction)
 
 Unmap the previously mapped scatter/gather list.  All the parameters
 must be the same as those and passed in to the scatter/gather mapping
@@ -348,18 +395,27 @@ API.
 Note: <nents> must be the number you passed in, *not* the number of
 DMA address entries returned.
 
-void
-dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
-			enum dma_data_direction direction)
-void
-dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
-			   enum dma_data_direction direction)
-void
-dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
-		    enum dma_data_direction direction)
-void
-dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
-		       enum dma_data_direction direction)
+::
+
+	void
+	dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+				size_t size,
+				enum dma_data_direction direction)
+
+	void
+	dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
+				   size_t size,
+				   enum dma_data_direction direction)
+
+	void
+	dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+			    int nents,
+			    enum dma_data_direction direction)
+
+	void
+	dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+			       int nents,
+			       enum dma_data_direction direction)
 
 Synchronise a single contiguous or scatter/gather mapping for the CPU
 and device. With the sync_sg API, all the parameters must be the same
@@ -367,36 +423,41 @@ as those passed into the single mapping API. With the sync_single API,
 you can use dma_handle and size parameters that aren't identical to
 those passed into the single mapping API to do a partial sync.
 
-Notes:  You must do this:
 
-- Before reading values that have been written by DMA from the device
-  (use the DMA_FROM_DEVICE direction)
-- After writing values that will be written to the device using DMA
-  (use the DMA_TO_DEVICE) direction
-- before *and* after handing memory to the device if the memory is
-  DMA_BIDIRECTIONAL
+.. note::
+
+   You must do this:
+
+   - Before reading values that have been written by DMA from the device
+     (use the DMA_FROM_DEVICE direction)
+   - After writing values that will be written to the device using DMA
+     (use the DMA_TO_DEVICE) direction
+   - before *and* after handing memory to the device if the memory is
+     DMA_BIDIRECTIONAL
 
 See also dma_map_single().
 
-dma_addr_t
-dma_map_single_attrs(struct device *dev, void *cpu_addr, size_t size,
-		     enum dma_data_direction dir,
-		     unsigned long attrs)
+::
 
-void
-dma_unmap_single_attrs(struct device *dev, dma_addr_t dma_addr,
-		       size_t size, enum dma_data_direction dir,
-		       unsigned long attrs)
+	dma_addr_t
+	dma_map_single_attrs(struct device *dev, void *cpu_addr, size_t size,
+			     enum dma_data_direction dir,
+			     unsigned long attrs)
 
-int
-dma_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
-		 int nents, enum dma_data_direction dir,
-		 unsigned long attrs)
+	void
+	dma_unmap_single_attrs(struct device *dev, dma_addr_t dma_addr,
+			       size_t size, enum dma_data_direction dir,
+			       unsigned long attrs)
 
-void
-dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sgl,
-		   int nents, enum dma_data_direction dir,
-		   unsigned long attrs)
+	int
+	dma_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
+			 int nents, enum dma_data_direction dir,
+			 unsigned long attrs)
+
+	void
+	dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sgl,
+			   int nents, enum dma_data_direction dir,
+			   unsigned long attrs)
 
 The four functions above are just like the counterpart functions
 without the _attrs suffixes, except that they pass an optional
@@ -410,37 +471,38 @@ is identical to those of the corresponding function
 without the _attrs suffix. As a result dma_map_single_attrs()
 can generally replace dma_map_single(), etc.
 
-As an example of the use of the *_attrs functions, here's how
+As an example of the use of the ``*_attrs`` functions, here's how
 you could pass an attribute DMA_ATTR_FOO when mapping memory
-for DMA:
+for DMA::
 
-#include <linux/dma-mapping.h>
-/* DMA_ATTR_FOO should be defined in linux/dma-mapping.h and
- * documented in Documentation/DMA-attributes.txt */
-...
+	#include <linux/dma-mapping.h>
+	/* DMA_ATTR_FOO should be defined in linux/dma-mapping.h and
+	* documented in Documentation/DMA-attributes.txt */
+	...
 
-	unsigned long attr;
-	attr |= DMA_ATTR_FOO;
-	....
-	n = dma_map_sg_attrs(dev, sg, nents, DMA_TO_DEVICE, attr);
-	....
+		unsigned long attr;
+		attr |= DMA_ATTR_FOO;
+		....
+		n = dma_map_sg_attrs(dev, sg, nents, DMA_TO_DEVICE, attr);
+		....
 
 Architectures that care about DMA_ATTR_FOO would check for its
 presence in their implementations of the mapping and unmapping
-routines, e.g.:
+routines, e.g.:::
 
-void whizco_dma_map_sg_attrs(struct device *dev, dma_addr_t dma_addr,
-			     size_t size, enum dma_data_direction dir,
-			     unsigned long attrs)
-{
-	....
-	if (attrs & DMA_ATTR_FOO)
-		/* twizzle the frobnozzle */
-	....
+	void whizco_dma_map_sg_attrs(struct device *dev, dma_addr_t dma_addr,
+				     size_t size, enum dma_data_direction dir,
+				     unsigned long attrs)
+	{
+		....
+		if (attrs & DMA_ATTR_FOO)
+			/* twizzle the frobnozzle */
+		....
+	}
 
 
-Part II - Advanced dma_ usage
------------------------------
+Part II - Advanced dma usage
+----------------------------
 
 Warning: These pieces of the DMA API should not be used in the
 majority of cases, since they cater for unlikely corner cases that
@@ -450,9 +512,11 @@ If you don't understand how cache line coherency works between a
 processor and an I/O device, you should not be using this part of the
 API at all.
 
-void *
-dma_alloc_noncoherent(struct device *dev, size_t size,
-			       dma_addr_t *dma_handle, gfp_t flag)
+::
+
+	void *
+	dma_alloc_noncoherent(struct device *dev, size_t size,
+			      dma_addr_t *dma_handle, gfp_t flag)
 
 Identical to dma_alloc_coherent() except that the platform will
 choose to return either consistent or non-consistent memory as it sees
@@ -468,39 +532,49 @@ only use this API if you positively know your driver will be
 required to work on one of the rare (usually non-PCI) architectures
 that simply cannot make consistent memory.
 
-void
-dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
-			      dma_addr_t dma_handle)
+::
+
+	void
+	dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
+			     dma_addr_t dma_handle)
 
 Free memory allocated by the nonconsistent API.  All parameters must
 be identical to those passed in (and returned by
 dma_alloc_noncoherent()).
 
-int
-dma_get_cache_alignment(void)
+::
+
+	int
+	dma_get_cache_alignment(void)
 
 Returns the processor cache alignment.  This is the absolute minimum
 alignment *and* width that you must observe when either mapping
 memory or doing partial flushes.
 
-Notes: This API may return a number *larger* than the actual cache
-line, but it will guarantee that one or more cache lines fit exactly
-into the width returned by this call.  It will also always be a power
-of two for easy alignment.
+.. note::
 
-void
-dma_cache_sync(struct device *dev, void *vaddr, size_t size,
-	       enum dma_data_direction direction)
+	This API may return a number *larger* than the actual cache
+	line, but it will guarantee that one or more cache lines fit exactly
+	into the width returned by this call.  It will also always be a power
+	of two for easy alignment.
+
+::
+
+	void
+	dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		       enum dma_data_direction direction)
 
 Do a partial sync of memory that was allocated by
 dma_alloc_noncoherent(), starting at virtual address vaddr and
 continuing on for size.  Again, you *must* observe the cache line
 boundaries when doing this.
 
-int
-dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-			    dma_addr_t device_addr, size_t size, int
-			    flags)
+::
+
+	int
+	dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
+				    dma_addr_t device_addr, size_t size, int
+				    flags)
 
 Declare region of memory to be handed out by dma_alloc_coherent() when
 it's asked for coherent memory for this device.
@@ -516,21 +590,21 @@ size is the size of the area (must be multiples of PAGE_SIZE).
 
 flags can be ORed together and are:
 
-DMA_MEMORY_MAP - request that the memory returned from
-dma_alloc_coherent() be directly writable.
+- DMA_MEMORY_MAP - request that the memory returned from
+  dma_alloc_coherent() be directly writable.
 
-DMA_MEMORY_IO - request that the memory returned from
-dma_alloc_coherent() be addressable using read()/write()/memcpy_toio() etc.
+- DMA_MEMORY_IO - request that the memory returned from
+  dma_alloc_coherent() be addressable using read()/write()/memcpy_toio() etc.
 
 One or both of these flags must be present.
 
-DMA_MEMORY_INCLUDES_CHILDREN - make the declared memory be allocated by
-dma_alloc_coherent of any child devices of this one (for memory residing
-on a bridge).
+- DMA_MEMORY_INCLUDES_CHILDREN - make the declared memory be allocated by
+  dma_alloc_coherent of any child devices of this one (for memory residing
+  on a bridge).
 
-DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions. 
-Do not allow dma_alloc_coherent() to fall back to system memory when
-it's out of memory in the declared region.
+- DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions.
+  Do not allow dma_alloc_coherent() to fall back to system memory when
+  it's out of memory in the declared region.
 
 The return value will be either DMA_MEMORY_MAP or DMA_MEMORY_IO and
 must correspond to a passed in flag (i.e. no returning DMA_MEMORY_IO
@@ -543,15 +617,17 @@ must be accessed using the correct bus functions.  If your driver
 isn't prepared to handle this contingency, it should not specify
 DMA_MEMORY_IO in the input flags.
 
-As a simplification for the platforms, only *one* such region of
+As a simplification for the platforms, only **one** such region of
 memory may be declared per device.
 
 For reasons of efficiency, most platforms choose to track the declared
 region only at the granularity of a page.  For smaller allocations,
 you should use the dma_pool() API.
 
-void
-dma_release_declared_memory(struct device *dev)
+::
+
+	void
+	dma_release_declared_memory(struct device *dev)
 
 Remove the memory region previously declared from the system.  This
 API performs *no* in-use checking for this region and will return
@@ -559,9 +635,11 @@ unconditionally having removed all the required structures.  It is the
 driver's job to ensure that no parts of this memory region are
 currently in use.
 
-void *
-dma_mark_declared_memory_occupied(struct device *dev,
-				  dma_addr_t device_addr, size_t size)
+::
+
+	void *
+	dma_mark_declared_memory_occupied(struct device *dev,
+					  dma_addr_t device_addr, size_t size)
 
 This is used to occupy specific regions of the declared space
 (dma_alloc_coherent() will hand out the first free region it finds).
@@ -592,38 +670,37 @@ option has a performance impact. Do not enable it in production kernels.
 If you boot the resulting kernel will contain code which does some bookkeeping
 about what DMA memory was allocated for which device. If this code detects an
 error it prints a warning message with some details into your kernel log. An
-example warning message may look like this:
+example warning message may look like this::
 
-------------[ cut here ]------------
-WARNING: at /data2/repos/linux-2.6-iommu/lib/dma-debug.c:448
-	check_unmap+0x203/0x490()
-Hardware name:
-forcedeth 0000:00:08.0: DMA-API: device driver frees DMA memory with wrong
-	function [device address=0x00000000640444be] [size=66 bytes] [mapped as
-single] [unmapped as page]
-Modules linked in: nfsd exportfs bridge stp llc r8169
-Pid: 0, comm: swapper Tainted: G        W  2.6.28-dmatest-09289-g8bb99c0 #1
-Call Trace:
- <IRQ>  [<ffffffff80240b22>] warn_slowpath+0xf2/0x130
- [<ffffffff80647b70>] _spin_unlock+0x10/0x30
- [<ffffffff80537e75>] usb_hcd_link_urb_to_ep+0x75/0xc0
- [<ffffffff80647c22>] _spin_unlock_irqrestore+0x12/0x40
- [<ffffffff8055347f>] ohci_urb_enqueue+0x19f/0x7c0
- [<ffffffff80252f96>] queue_work+0x56/0x60
- [<ffffffff80237e10>] enqueue_task_fair+0x20/0x50
- [<ffffffff80539279>] usb_hcd_submit_urb+0x379/0xbc0
- [<ffffffff803b78c3>] cpumask_next_and+0x23/0x40
- [<ffffffff80235177>] find_busiest_group+0x207/0x8a0
- [<ffffffff8064784f>] _spin_lock_irqsave+0x1f/0x50
- [<ffffffff803c7ea3>] check_unmap+0x203/0x490
- [<ffffffff803c8259>] debug_dma_unmap_page+0x49/0x50
- [<ffffffff80485f26>] nv_tx_done_optimized+0xc6/0x2c0
- [<ffffffff80486c13>] nv_nic_irq_optimized+0x73/0x2b0
- [<ffffffff8026df84>] handle_IRQ_event+0x34/0x70
- [<ffffffff8026ffe9>] handle_edge_irq+0xc9/0x150
- [<ffffffff8020e3ab>] do_IRQ+0xcb/0x1c0
- [<ffffffff8020c093>] ret_from_intr+0x0/0xa
- <EOI> <4>---[ end trace f6435a98e2a38c0e ]---
+	WARNING: at /data2/repos/linux-2.6-iommu/lib/dma-debug.c:448
+		check_unmap+0x203/0x490()
+	Hardware name:
+	forcedeth 0000:00:08.0: DMA-API: device driver frees DMA memory with wrong
+		function [device address=0x00000000640444be] [size=66 bytes] [mapped as
+	single] [unmapped as page]
+	Modules linked in: nfsd exportfs bridge stp llc r8169
+	Pid: 0, comm: swapper Tainted: G        W  2.6.28-dmatest-09289-g8bb99c0 #1
+	Call Trace:
+	<IRQ>  [<ffffffff80240b22>] warn_slowpath+0xf2/0x130
+	[<ffffffff80647b70>] _spin_unlock+0x10/0x30
+	[<ffffffff80537e75>] usb_hcd_link_urb_to_ep+0x75/0xc0
+	[<ffffffff80647c22>] _spin_unlock_irqrestore+0x12/0x40
+	[<ffffffff8055347f>] ohci_urb_enqueue+0x19f/0x7c0
+	[<ffffffff80252f96>] queue_work+0x56/0x60
+	[<ffffffff80237e10>] enqueue_task_fair+0x20/0x50
+	[<ffffffff80539279>] usb_hcd_submit_urb+0x379/0xbc0
+	[<ffffffff803b78c3>] cpumask_next_and+0x23/0x40
+	[<ffffffff80235177>] find_busiest_group+0x207/0x8a0
+	[<ffffffff8064784f>] _spin_lock_irqsave+0x1f/0x50
+	[<ffffffff803c7ea3>] check_unmap+0x203/0x490
+	[<ffffffff803c8259>] debug_dma_unmap_page+0x49/0x50
+	[<ffffffff80485f26>] nv_tx_done_optimized+0xc6/0x2c0
+	[<ffffffff80486c13>] nv_nic_irq_optimized+0x73/0x2b0
+	[<ffffffff8026df84>] handle_IRQ_event+0x34/0x70
+	[<ffffffff8026ffe9>] handle_edge_irq+0xc9/0x150
+	[<ffffffff8020e3ab>] do_IRQ+0xcb/0x1c0
+	[<ffffffff8020c093>] ret_from_intr+0x0/0xa
+	<EOI> <4>---[ end trace f6435a98e2a38c0e ]---
 
 The driver developer can find the driver and the device including a stacktrace
 of the DMA-API call which caused this warning.
@@ -637,43 +714,42 @@ details.
 The debugfs directory for the DMA-API debugging code is called dma-api/. In
 this directory the following files can currently be found:
 
-	dma-api/all_errors	This file contains a numeric value. If this
+=============================== ===============================================
+dma-api/all_errors		This file contains a numeric value. If this
 				value is not equal to zero the debugging code
 				will print a warning for every error it finds
 				into the kernel log. Be careful with this
 				option, as it can easily flood your logs.
 
-	dma-api/disabled	This read-only file contains the character 'Y'
+dma-api/disabled		This read-only file contains the character 'Y'
 				if the debugging code is disabled. This can
 				happen when it runs out of memory or if it was
 				disabled at boot time
 
-	dma-api/error_count	This file is read-only and shows the total
+dma-api/error_count		This file is read-only and shows the total
 				numbers of errors found.
 
-	dma-api/num_errors	The number in this file shows how many
+dma-api/num_errors		The number in this file shows how many
 				warnings will be printed to the kernel log
 				before it stops. This number is initialized to
 				one at system boot and be set by writing into
 				this file
 
-	dma-api/min_free_entries
-				This read-only file can be read to get the
+dma-api/min_free_entries	This read-only file can be read to get the
 				minimum number of free dma_debug_entries the
 				allocator has ever seen. If this value goes
 				down to zero the code will disable itself
 				because it is not longer reliable.
 
-	dma-api/num_free_entries
-				The current number of free dma_debug_entries
+dma-api/num_free_entries	The current number of free dma_debug_entries
 				in the allocator.
 
-	dma-api/driver-filter
-				You can write a name of a driver into this file
+dma-api/driver-filter		You can write a name of a driver into this file
 				to limit the debug output to requests from that
 				particular driver. Write an empty string to
 				that file to disable the filter and see
 				all errors again.
+=============================== ===============================================
 
 If you have this code compiled into your kernel it will be enabled by default.
 If you want to boot without the bookkeeping anyway you can provide
@@ -692,7 +768,10 @@ 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_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
+::
+
+	void
+	debug_dma_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
@@ -702,4 +781,3 @@ 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.
-
-- 
2.9.4