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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-10 11:54:48 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-10 11:54:48 -0700 |
commit | b7a7d1c1ec688104fdc922568c26395a756f616d (patch) | |
tree | 8059a401de91431615737b088f3da20d4567683e /Documentation/DMA-API.txt | |
parent | 065b6c4c913d3986c2118acb7e7fb364ce4fb625 (diff) | |
parent | 9eb9e96e97b3381e94cba81d93f4a390c26ca6cb (diff) | |
download | lwn-b7a7d1c1ec688104fdc922568c26395a756f616d.tar.gz lwn-b7a7d1c1ec688104fdc922568c26395a756f616d.zip |
Merge tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mapping
Pull DMA mapping updates from Christoph Hellwig:
- add debugfs support for dumping dma-debug information (Corentin
Labbe)
- Kconfig cleanups (Andy Shevchenko and me)
- debugfs cleanups (Greg Kroah-Hartman)
- improve dma_map_resource and use it in the media code
- arch_setup_dma_ops / arch_teardown_dma_ops cleanups
- various small cleanups and improvements for the per-device coherent
allocator
- make the DMA mask an upper bound and don't fail "too large" dma mask
in the remaning two architectures - this will allow big driver
cleanups in the following merge windows
* tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mapping: (21 commits)
Documentation/DMA-API-HOWTO: update dma_mask sections
sparc64/pci_sun4v: allow large DMA masks
sparc64/iommu: allow large DMA masks
sparc64: refactor the ali DMA quirk
ccio: allow large DMA masks
dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag
dma-mapping: remove dma_mark_declared_memory_occupied
dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig
dma-mapping: improve selection of dma_declare_coherent availability
dma-mapping: remove an incorrect __iommem annotation
of: select OF_RESERVED_MEM automatically
device.h: dma_mem is only needed for HAVE_GENERIC_DMA_COHERENT
mfd/sm501: depend on HAS_DMA
dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability
dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability
dma-mapping: move debug configuration options to kernel/dma
dma-debug: add dumping facility via debugfs
dma: debug: no need to check return value of debugfs_create functions
videobuf2: replace a layering violation with dma_map_resource
dma-mapping: don't BUG when calling dma_map_resource on RAM
...
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r-- | Documentation/DMA-API.txt | 29 |
1 files changed, 4 insertions, 25 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 607c1e75e5aa..586643642910 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -566,8 +566,7 @@ 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) + dma_addr_t device_addr, size_t size); Declare region of memory to be handed out by dma_alloc_coherent() when it's asked for coherent memory for this device. @@ -581,12 +580,6 @@ dma_addr_t in dma_alloc_coherent()). size is the size of the area (must be multiples of PAGE_SIZE). -flags can be ORed together and are: - -- 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. - As a simplification for the platforms, only *one* such region of memory may be declared per device. @@ -605,23 +598,6 @@ 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) - -This is used to occupy specific regions of the declared space -(dma_alloc_coherent() will hand out the first free region it finds). - -device_addr is the *device* address of the region requested. - -size is the size (and should be a page-sized multiple). - -The return value will be either a pointer to the processor virtual -address of the memory, or an error (via PTR_ERR()) if any part of the -region is occupied. - Part III - Debug drivers use of the DMA-API ------------------------------------------- @@ -696,6 +672,9 @@ dma-api/disabled This read-only file contains the character 'Y' happen when it runs out of memory or if it was disabled at boot time +dma-api/dump This read-only file contains current DMA + mappings. + dma-api/error_count This file is read-only and shows the total numbers of errors found. |