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authorChristoph Hellwig <hch@lst.de>2018-09-11 08:55:28 +0200
committerChristoph Hellwig <hch@lst.de>2018-09-20 09:01:16 +0200
commit58b0440663ec11372befb8ead0ee7099d8878590 (patch)
treec613ed22ad229e6612d8c71888d2bb8139163ea8 /arch/arc
parentbc3ec75de5452db59b683487867ba562b950708a (diff)
downloadlinux-58b0440663ec11372befb8ead0ee7099d8878590.tar.gz
dma-mapping: consolidate the dma mmap implementations
The only functional differences (modulo a few missing fixes in the arch code) is that architectures without coherent caches need a hook to convert a virtual or dma address into a pfn, given that we don't have the kernel linear mapping available for the otherwise easy virt_to_page call. As a side effect we can support mmap of the per-device coherent area even on architectures not providing the callback, and we make previous dangerous default methods dma_common_mmap actually save for non-coherent architectures by rejecting it without the right helper. In addition to that we need a hook so that some architectures can override the protection bits when mmaping a dma coherent allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/Kconfig2
-rw-r--r--arch/arc/mm/dma.c25
2 files changed, 4 insertions, 23 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index ca03694d518a..3d9bdecfa52d 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -9,6 +9,7 @@
config ARC
def_bool y
select ARC_TIMERS
+ select ARCH_HAS_DMA_COHERENT_TO_PFN
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
@@ -18,7 +19,6 @@ config ARC
select CLONE_BACKWARDS
select COMMON_CLK
select DMA_DIRECT_OPS
- select DMA_NONCOHERENT_MMAP
select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)
select GENERIC_CLOCKEVENTS
select GENERIC_FIND_FIRST_BIT
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 535ed4a068ef..db203ff69ccf 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -84,29 +84,10 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
__free_pages(page, get_order(size));
}
-int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size,
- unsigned long attrs)
+long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
+ dma_addr_t dma_addr)
{
- unsigned long user_count = vma_pages(vma);
- unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long pfn = __phys_to_pfn(dma_addr);
- unsigned long off = vma->vm_pgoff;
- int ret = -ENXIO;
-
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
- if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
-
- if (off < count && user_count <= (count - off)) {
- ret = remap_pfn_range(vma, vma->vm_start,
- pfn + off,
- user_count << PAGE_SHIFT,
- vma->vm_page_prot);
- }
-
- return ret;
+ return __phys_to_pfn(dma_addr);
}
/*