forked from Minki/linux
ce88313069
Some devices may have a non-zero DMA offset, i.e an offset between the DMA address and the physical address. Such an offset can be encoded into the dma_pfn_offset field of "struct device", but the SuperH implementation of the DMA mapping API does not observe this information. This commit fixes that by ensuring the DMA address is properly calculated depending on this DMA offset. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Rich Felker <dalias@libc.org>
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
/*
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* DMA mapping support for platforms lacking IOMMUs.
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*
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* Copyright (C) 2009 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/dma-mapping.h>
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#include <linux/io.h>
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#include <asm/cacheflush.h>
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static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction dir,
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unsigned long attrs)
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{
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dma_addr_t addr = page_to_phys(page) + offset
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- PFN_PHYS(dev->dma_pfn_offset);
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WARN_ON(size == 0);
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if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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sh_sync_dma_for_device(page_address(page) + offset, size, dir);
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return addr;
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}
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static int nommu_map_sg(struct device *dev, struct scatterlist *sg,
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int nents, enum dma_data_direction dir,
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unsigned long attrs)
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{
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struct scatterlist *s;
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int i;
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WARN_ON(nents == 0 || sg[0].length == 0);
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for_each_sg(sg, s, nents, i) {
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dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset);
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BUG_ON(!sg_page(s));
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if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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sh_sync_dma_for_device(sg_virt(s), s->length, dir);
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s->dma_address = sg_phys(s) - offset;
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s->dma_length = s->length;
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}
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return nents;
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}
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#ifdef CONFIG_DMA_NONCOHERENT
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static void nommu_sync_single_for_device(struct device *dev, dma_addr_t addr,
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size_t size, enum dma_data_direction dir)
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{
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sh_sync_dma_for_device(phys_to_virt(addr), size, dir);
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}
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static void nommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
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int nelems, enum dma_data_direction dir)
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{
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struct scatterlist *s;
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int i;
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for_each_sg(sg, s, nelems, i)
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sh_sync_dma_for_device(sg_virt(s), s->length, dir);
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}
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#endif
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const struct dma_map_ops nommu_dma_ops = {
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.alloc = dma_generic_alloc_coherent,
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.free = dma_generic_free_coherent,
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.map_page = nommu_map_page,
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.map_sg = nommu_map_sg,
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#ifdef CONFIG_DMA_NONCOHERENT
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.sync_single_for_device = nommu_sync_single_for_device,
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.sync_sg_for_device = nommu_sync_sg_for_device,
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#endif
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.is_phys = 1,
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};
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void __init no_iommu_init(void)
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{
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if (dma_ops)
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return;
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dma_ops = &nommu_dma_ops;
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}
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