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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-12 13:30:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-12 13:30:06 -0700
commit52269718dc2cf2585d7a2828f31d46ef46e68000 (patch)
tree9815c6cbaa8c2e3247b6356725c150831dfd4d4e /Documentation
parentae71948f398eb2572148006bf34f0c6d934206cb (diff)
parentd35b0996fef3bfe76665e87bbff7d95c6807350a (diff)
download96b-common-52269718dc2cf2585d7a2828f31d46ef46e68000.tar.gz
Merge tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig: - removal of the old dma_alloc_noncoherent interface - remove unused flags to dma_declare_coherent_memory - restrict OF DMA configuration to specific physical busses - use the iommu mailing list for dma-mapping questions and patches * tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping: dma-coherent: fix dma_declare_coherent_memory() logic error ARM: imx: mx31moboard: Remove unused 'dma' variable dma-coherent: remove an unused variable MAINTAINERS: use the iommu list for the dma-mapping subsystem dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags dma-coherent: remove the DMA_MEMORY_INCLUDES_CHILDREN flag of: restrict DMA configuration dma-mapping: remove dma_alloc_noncoherent and dma_free_noncoherent i825xx: switch to switch to dma_alloc_attrs au1000_eth: switch to dma_alloc_attrs sgiseeq: switch to dma_alloc_attrs dma-mapping: reduce dma_mapping_error inline bloat
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DMA-API.txt55
1 files changed, 17 insertions, 38 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 45b29326d719..ac66ae2509a9 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -515,14 +515,15 @@ API at all.
::
void *
- dma_alloc_noncoherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag)
+ dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
+ gfp_t flag, unsigned long attrs)
-Identical to dma_alloc_coherent() except that the platform will
-choose to return either consistent or non-consistent memory as it sees
-fit. By using this API, you are guaranteeing to the platform that you
-have all the correct and necessary sync points for this memory in the
-driver should it choose to return non-consistent memory.
+Identical to dma_alloc_coherent() except that when the
+DMA_ATTR_NON_CONSISTENT flags is passed in the attrs argument, the
+platform will choose to return either consistent or non-consistent memory
+as it sees fit. By using this API, you are guaranteeing to the platform
+that you have all the correct and necessary sync points for this memory
+in the driver should it choose to return non-consistent memory.
Note: where the platform can return consistent memory, it will
guarantee that the sync points become nops.
@@ -535,12 +536,13 @@ that simply cannot make consistent memory.
::
void
- dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t dma_handle)
+ dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t dma_handle, unsigned long attrs)
-Free memory allocated by the nonconsistent API. All parameters must
-be identical to those passed in (and returned by
-dma_alloc_noncoherent()).
+Free memory allocated by the dma_alloc_attrs(). All parameters common
+parameters must identical to those otherwise passed to dma_fre_coherent,
+and the attrs argument must be identical to the attrs passed to
+dma_alloc_attrs().
::
@@ -564,8 +566,8 @@ memory or doing partial flushes.
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
+Do a partial sync of memory that was allocated by dma_alloc_attrs() with
+the DMA_ATTR_NON_CONSISTENT flag starting at virtual address vaddr and
continuing on for size. Again, you *must* observe the cache line
boundaries when doing this.
@@ -590,34 +592,11 @@ 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_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_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
-if only DMA_MEMORY_MAP were passed in) for success or zero for
-failure.
-
-Note, for DMA_MEMORY_IO returns, all subsequent memory returned by
-dma_alloc_coherent() may no longer be accessed directly, but instead
-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