kernel/include/asm-generic/dma-mapping-common.h, branch linux-4.1.y

asm/dma-mapping-common: Clarify output of dma_map_sg_attrs

2015-03-09T12:05:47Z

Although dma_map_sg_attrs returns 0 on error and it cannot return a value < 0, the function returns a signed integer. Most of the time, this function is used with a scatterlist structure. This structure uses an unsigned integer for the number of memory. A dma developer that has not read in detail DMA-API.txt, can wrongly return a value < 0 on error. The comment will help the driver developer, and the WARN_ON the dma developer. Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Marek Szyprowski

Merge branch 'for-v3.18' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

2014-10-10T20:56:08Z

Pull dma-mapping update from Marek Szyprowski: "Provide the dma write coherent api (available previously on ARM architecture) for all other architectures, which use dma_ops-based dma mapping implementation. This lets one to use the same code in the device drivers regardless of the selected architecture" * 'for-v3.18' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: dma-mapping: Provide write-combine allocations s390: Implement dma_{alloc,free}_attrs()

common: dma-mapping: introduce common remapping functions

2014-10-10T02:25:52Z

For architectures without coherent DMA, memory for DMA may need to be remapped with coherent attributes. Factor out the the remapping code from arm and put it in a common location to reduce code duplication. As part of this, the arm APIs are now migrated away from ioremap_page_range to the common APIs which use map_vm_area for remapping. This should be an equivalent change and using map_vm_area is more correct as ioremap_page_range is intended to bring in io addresses into the cpu space and not regular kernel managed memory. Signed-off-by: Laura Abbott Reviewed-by: Catalin Marinas Cc: Arnd Bergmann Cc: David Riley Cc: Olof Johansson Cc: Ritesh Harjain Cc: Russell King Cc: Thierry Reding Cc: Will Deacon Cc: James Hogan Cc: Laura Abbott Cc: Mitchel Humpherys Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: Provide write-combine allocations

2014-08-26T05:39:13Z

Provide an implementation for dma_{alloc,free,mmap}_writecombine() when the architecture supports DMA attributes. Signed-off-by: Thierry Reding Acked-by: Arnd Bergmann Signed-off-by: Marek Szyprowski

common: dma-mapping: introduce dma_get_sgtable() function

2012-07-30T10:25:46Z

This patch adds dma_get_sgtable() function which is required to let drivers to share the buffers allocated by DMA-mapping subsystem. Right now the driver gets a dma address of the allocated buffer and the kernel virtual mapping for it. If it wants to share it with other device (= map into its dma address space) it usually hacks around kernel virtual addresses to get pointers to pages or assumes that both devices share the DMA address space. Both solutions are just hacks for the special cases, which should be avoided in the final version of buffer sharing. To solve this issue in a generic way, a new call to DMA mapping has been introduced - dma_get_sgtable(). It allocates a scatter-list which describes the allocated buffer and lets the driver(s) to use it with other device(s) by calling dma_map_sg() on it. This patch provides a generic implementation based on virt_to_page() call. Architectures which require more sophisticated translation might provide their own get_sgtable() methods. Signed-off-by: Marek Szyprowski Reviewed-by: Kyungmin Park Reviewed-by: Daniel Vetter

common: dma-mapping: add support for generic dma_mmap_* calls

2012-07-30T10:25:46Z

Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a generic method for implementing mmap user call to dma_map_ops structure. This patch converts ARM and PowerPC architectures (the only providers of dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic dma_map_ops based call and adds a generic cross architecture definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine functions. The generic mmap virt_to_page-based fallback implementation is provided for architectures which don't provide their own implementation for mmap method. Signed-off-by: Marek Szyprowski Reviewed-by: Kyungmin Park

BUG: headers with BUG/BUG_ON etc. need linux/bug.h

2012-03-04T22:54:34Z

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker

dma-mapping: fix sync_single_range_* DMA debugging

2011-11-01T00:30:44Z

Commit 5fd75a7850b5 (dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops) unified not only the dma_map_ops but also the corresponding debug_dma_sync_* calls. This led to spurious WARN()ings like the following because the DMA debug code was no longer able to detect the DMA buffer base address without the separate offset parameter: WARNING: at lib/dma-debug.c:911 check_sync+0xce/0x446() firewire_ohci 0000:04:00.0: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x00000000cedaa400] [size=1024 bytes] Call Trace: ... [] check_sync+0xce/0x446 [] debug_dma_sync_single_for_device+0x39/0x3b [] ohci_queue_iso+0x4f3/0x77d [firewire_ohci] ... To fix this, unshare the sync_single_* and sync_single_range_* implementations so that we are able to call the correct debug_dma_sync_* functions. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Clemens Ladisch Cc: FUJITA Tomonori Cc: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops

2010-05-27T16:12:52Z

sync_single_range_for_cpu and sync_single_range_for_device hooks are unnecessary because sync_single_for_cpu and sync_single_for_device can be used instead. Signed-off-by: FUJITA Tomonori Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: fix dma_sync_single_range_*

2010-05-12T00:33:41Z

dma_sync_single_range_for_cpu() and dma_sync_single_range_for_device() use a wrong address with a partial synchronization. Signed-off-by: FUJITA Tomonori Reviewed-by: Konrad Rzeszutek Wilk Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds