summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-19 13:27:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-19 13:27:23 -0700
commit671df189537883f36cf9c7d4f9495bfac0f86627 (patch)
tree22e5f598ed1f5d9b2218d85d4426140f804d61e6 /Documentation
parentc9fe5630dae1df2328d82042602e2c4d1add8d57 (diff)
parentc7d9eccb3c1e802c5cbb2a764eb0eb9807d9f12e (diff)
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.txt19
-rw-r--r--Documentation/x86/x86_64/boot-options.rst2
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"