---------------------
.. note::
If anything below doesn't make sense, please refer to
- Documentation/DMA-API.txt. This section is just a reminder that
+ :doc:`/core-api/dma-api`. This section is just a reminder that
drivers need to indicate DMA capabilities of the device and is not
an authoritative source for DMA interfaces.
Setup shared control data
-------------------------
Once the DMA masks are set, the driver can allocate "consistent" (a.k.a. shared)
-memory. See Documentation/DMA-API.txt for a full description of
+memory. See :doc:`/core-api/dma-api` for a full description of
the DMA APIs. This section is just a reminder that it needs to be done
before enabling DMA on the device.
Then clean up "consistent" buffers which contain the control data.
-See Documentation/DMA-API.txt for details on unmapping interfaces.
+See :doc:`/core-api/dma-api` for details on unmapping interfaces.
Unregister from other subsystems
do not have a corresponding kernel virtual address space mapping) and
low-memory pages.
-Note: Please refer to Documentation/DMA-API-HOWTO.txt for a discussion
+Note: Please refer to :doc:`/core-api/dma-api-howto` for a discussion
on PCI high mem DMA aspects and mapping of scatter gather lists, and support
for 64 bit PCI.
The virt_to_bus() and bus_to_virt() functions have been
superseded by the functionality provided by the PCI DMA interface
- (see Documentation/DMA-API-HOWTO.txt). They continue
+ (see :doc:`/core-api/dma-api-howto`). They continue
to be documented below for historical purposes, but new code
must not use them. --davidm 00/12/12
:Author: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
This document describes the DMA API. For a more gentle introduction
-of the API (and actual examples), see Documentation/DMA-API-HOWTO.txt.
+of the API (and actual examples), see :doc:`/core-api/dma-api-howto`.
This API is split into two pieces. Part I describes the basic API.
Part II describes extensions for supporting non-consistent memory
dma_attrs.
The interpretation of DMA attributes is architecture-specific, and
-each attribute should be documented in Documentation/DMA-attributes.txt.
+each attribute should be documented in :doc:`/core-api/dma-attributes`.
If dma_attrs are 0, the semantics of each of these functions
is identical to those of the corresponding function
#include <linux/dma-mapping.h>
/* DMA_ATTR_FOO should be defined in linux/dma-mapping.h and
- * documented in Documentation/DMA-attributes.txt */
+ * documented in Documentation/core-api/dma-attributes.rst */
...
unsigned long attr;
#include <asm/dma.h>
The first is the generic DMA API used to convert virtual addresses to
-bus addresses (see Documentation/DMA-API.txt for details).
+bus addresses (see :doc:`/core-api/dma-api` for details).
The second contains the routines specific to ISA DMA transfers. Since
this is not present on all platforms make sure you construct your
The big picture is that USB drivers can continue to ignore most DMA issues,
though they still must provide DMA-ready buffers (see
-``Documentation/DMA-API-HOWTO.txt``). That's how they've worked through
+:doc:`/core-api/dma-api-howto`). That's how they've worked through
the 2.4 (and earlier) kernels, or they can now be DMA-aware.
DMA-aware usb drivers:
force a consistent memory access ordering by using memory barriers. It's
not using a streaming DMA mapping, so it's good for small transfers on
systems where the I/O would otherwise thrash an IOMMU mapping. (See
- ``Documentation/DMA-API-HOWTO.txt`` for definitions of "coherent" and
+ :doc:`/core-api/dma-api-howto` for definitions of "coherent" and
"streaming" DMA mappings.)
Asking for 1/Nth of a page (as well as asking for N pages) is reasonably
Existing buffers aren't usable for DMA without first being mapped into the
DMA address space of the device. However, most buffers passed to your
driver can safely be used with such DMA mapping. (See the first section
-of Documentation/DMA-API-HOWTO.txt, titled "What memory is DMA-able?")
+of :doc:`/core-api/dma-api-howto`, titled "What memory is DMA-able?")
- When you're using scatterlists, you can map everything at once. On some
systems, this kicks in an IOMMU and turns the scatterlists into single
[*] 버스 마스터링 DMA 와 일관성에 대해서는 다음을 참고하시기 바랍니다:
Documentation/driver-api/pci/pci.rst
- Documentation/DMA-API-HOWTO.txt
- Documentation/DMA-API.txt
+ Documentation/core-api/dma-api-howto.rst
+ Documentation/core-api/dma-api.rst
데이터 의존성 배리어 (역사적)
writel_relaxed() 와 같은 완화된 I/O 접근자들에 대한 자세한 내용을 위해서는
"커널 I/O 배리어의 효과" 섹션을, consistent memory 에 대한 자세한 내용을
- 위해선 Documentation/DMA-API.txt 문서를 참고하세요.
+ 위해선 Documentation/core-api/dma-api.rst 문서를 참고하세요.
=========================
* @dir: dma direction
* @attrs: optional dma attributes
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static dma_addr_t sba_map_page(struct device *dev, struct page *page,
unsigned long poff, size_t size,
* @dir: R/W or both.
* @attrs: optional dma attributes
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
enum dma_data_direction dir, unsigned long attrs)
* @size: number of bytes mapped in driver buffer.
* @dma_handle: IOVA of new buffer.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void *
sba_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
* @vaddr: virtual address IOVA of "consistent" buffer.
* @dma_handler: IO virtual address of "consistent" buffer.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void sba_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
* @dir: R/W or both.
* @attrs: optional dma attributes
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static int sba_map_sg_attrs(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction dir,
* @dir: R/W or both.
* @attrs: optional dma attributes
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void sba_unmap_sg_attrs(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction dir,
** PARISC 1.1 Dynamic DMA mapping support.
** This implementation is for PA-RISC platforms that do not support
** I/O TLBs (aka DMA address translation hardware).
-** See Documentation/DMA-API-HOWTO.txt for interface definitions.
+** See Documentation/core-api/dma-api-howto.rst for interface definitions.
**
** (c) Copyright 1999,2000 Hewlett-Packard Company
** (c) Copyright 2000 Grant Grundler
#define _ASM_X86_DMA_MAPPING_H
/*
- * IOMMU interface. See Documentation/DMA-API-HOWTO.txt and
- * Documentation/DMA-API.txt for documentation.
+ * IOMMU interface. See Documentation/core-api/dma-api-howto.rst and
+ * Documentation/core-api/dma-api.rst for documentation.
*/
#include <linux/scatterlist.h>
* This allows to use PCI devices that only support 32bit addresses on systems
* with more than 4GB.
*
- * See Documentation/DMA-API-HOWTO.txt for the interface specification.
+ * See Documentation/core-api/dma-api-howto.rst for the interface specification.
*
* Copyright 2002 Andi Kleen, SuSE Labs.
*/
* @dev: instance of PCI owned by the driver that's asking
* @mask: number of address bits this PCI device can handle
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static int sba_dma_supported( struct device *dev, u64 mask)
{
* @size: number of bytes to map in driver buffer.
* @direction: R/W or both.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static dma_addr_t
sba_map_single(struct device *dev, void *addr, size_t size,
* @size: number of bytes mapped in driver buffer.
* @direction: R/W or both.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void
sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
* @size: number of bytes mapped in driver buffer.
* @dma_handle: IOVA of new buffer.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void *sba_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
* @vaddr: virtual address IOVA of "consistent" buffer.
* @dma_handler: IO virtual address of "consistent" buffer.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void
sba_free(struct device *hwdev, size_t size, void *vaddr,
* @nents: number of entries in list
* @direction: R/W or both.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static int
sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
* @nents: number of entries in list
* @direction: R/W or both.
*
- * See Documentation/DMA-API-HOWTO.txt
+ * See Documentation/core-api/dma-api-howto.rst
*/
static void
sba_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
/**
* List of possible attributes associated with a DMA mapping. The semantics
- * of each attribute should be defined in Documentation/DMA-attributes.txt.
+ * of each attribute should be defined in Documentation/core-api/dma-attributes.rst.
*/
/*
* does memory allocation too using vmalloc_32().
*
* videobuf_dma_*()
- * see Documentation/DMA-API-HOWTO.txt, these functions to
+ * see Documentation/core-api/dma-api-howto.rst, these functions to
* basically the same. The map function does also build a
* scatterlist for the buffer (and unmap frees it ...)
*
/*
* Drivers should use dma_mapping_error() to check the returned
* addresses of dma_map_single() and dma_map_page().
- * If not, print this warning message. See Documentation/DMA-API.txt.
+ * If not, print this warning message. See Documentation/core-api/dma-api.rst.
*/
if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
err_printk(ref->dev, entry,
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