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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-19 23:27:23 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-19 23:27:23 +0300 |
commit | 671df189537883f36cf9c7d4f9495bfac0f86627 (patch) | |
tree | 22e5f598ed1f5d9b2218d85d4426140f804d61e6 /Documentation | |
parent | c9fe5630dae1df2328d82042602e2c4d1add8d57 (diff) | |
parent | c7d9eccb3c1e802c5cbb2a764eb0eb9807d9f12e (diff) | |
download | linux-671df189537883f36cf9c7d4f9495bfac0f86627.tar.xz |
Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- add dma-mapping and block layer helpers to take care of IOMMU merging
for mmc plus subsequent fixups (Yoshihiro Shimoda)
- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask
(me)
- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
mmc: queue: Fix bigger segments usage
arm64: use asm-generic/dma-mapping.h
swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
swiotlb-xen: simplify cache maintainance
swiotlb-xen: use the same foreign page check everywhere
swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
xen: remove the exports for xen_{create,destroy}_contiguous_region
xen/arm: remove xen_dma_ops
xen/arm: simplify dma_cache_maint
xen/arm: use dev_is_dma_coherent
xen/arm: consolidate page-coherent.h
xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
arm: remove wrappers for the generic dma remap helpers
dma-mapping: introduce a dma_common_find_pages helper
dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
vmalloc: lift the arm flag for coherent mappings to common code
dma-mapping: provide a better default ->get_required_mask
dma-mapping: remove the dma_declare_coherent_memory export
remoteproc: don't allow modular build
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/DMA-API.txt | 19 | ||||
-rw-r--r-- | Documentation/x86/x86_64/boot-options.rst | 2 |
2 files changed, 9 insertions, 12 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e47c63bd4887..2d8d2fed7317 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -204,6 +204,14 @@ Returns the maximum size of a mapping for the device. The size parameter of the mapping functions like dma_map_single(), dma_map_page() and others should not be larger than the returned value. +:: + + unsigned long + dma_get_merge_boundary(struct device *dev); + +Returns the DMA merge boundary. If the device cannot merge any the DMA address +segments, the function returns 0. + Part Id - Streaming DMA mappings -------------------------------- @@ -595,17 +603,6 @@ 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) - -Remove the memory region previously declared from the system. This -API performs *no* in-use checking for this region and will return -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. - Part III - Debug drivers use of the DMA-API ------------------------------------------- diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst index 6a4285a3c7a4..2b98efb5ba7f 100644 --- a/Documentation/x86/x86_64/boot-options.rst +++ b/Documentation/x86/x86_64/boot-options.rst @@ -230,7 +230,7 @@ IOMMU (input/output memory management unit) =========================================== Multiple x86-64 PCI-DMA mapping implementations exist, for example: - 1. <lib/dma-direct.c>: use no hardware/software IOMMU at all + 1. <kernel/dma/direct.c>: use no hardware/software IOMMU at all (e.g. because you have < 3 GB memory). Kernel boot message: "PCI-DMA: Disabling IOMMU" |