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58b0440663
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
45 lines
1.0 KiB
C
45 lines
1.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2009-2010 PetaLogix
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* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
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*
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* Provide default implementations of the DMA mapping callbacks for
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* directly mapped busses.
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*/
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#include <linux/device.h>
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#include <linux/dma-noncoherent.h>
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#include <linux/gfp.h>
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#include <linux/dma-debug.h>
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#include <linux/export.h>
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#include <linux/bug.h>
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#include <asm/cacheflush.h>
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static void __dma_sync(struct device *dev, phys_addr_t paddr, size_t size,
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enum dma_data_direction direction)
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{
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switch (direction) {
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case DMA_TO_DEVICE:
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case DMA_BIDIRECTIONAL:
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flush_dcache_range(paddr, paddr + size);
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break;
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case DMA_FROM_DEVICE:
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invalidate_dcache_range(paddr, paddr + size);
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break;
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default:
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BUG();
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}
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}
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void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
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size_t size, enum dma_data_direction dir)
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{
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__dma_sync(dev, paddr, size, dir);
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}
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void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
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size_t size, enum dma_data_direction dir)
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{
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__dma_sync(dev, paddr, size, dir);
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}
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