114 строки
2.8 KiB
C
114 строки
2.8 KiB
C
/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/dma-mapping.h>
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#include <linux/list.h>
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#include <linux/pci.h>
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#include <linux/export.h>
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#include <linux/highmem.h>
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#include <linux/scatterlist.h>
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#include <asm/io.h>
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static void *frv_dma_alloc(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
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{
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void *ret;
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ret = consistent_alloc(gfp, size, dma_handle);
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if (ret)
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memset(ret, 0, size);
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return ret;
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}
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static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
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dma_addr_t dma_handle, unsigned long attrs)
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{
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consistent_free(vaddr);
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}
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static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
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int nents, enum dma_data_direction direction,
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unsigned long attrs)
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{
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unsigned long dampr2;
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void *vaddr;
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int i;
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struct scatterlist *sg;
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BUG_ON(direction == DMA_NONE);
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dampr2 = __get_DAMPR(2);
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for_each_sg(sglist, sg, nents, i) {
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vaddr = kmap_atomic_primary(sg_page(sg));
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frv_dcache_writeback((unsigned long) vaddr,
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(unsigned long) vaddr + PAGE_SIZE);
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}
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kunmap_atomic_primary(vaddr);
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if (dampr2) {
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__set_DAMPR(2, dampr2);
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__set_IAMPR(2, dampr2);
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}
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return nents;
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}
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static dma_addr_t frv_dma_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 direction, unsigned long attrs)
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{
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flush_dcache_page(page);
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return (dma_addr_t) page_to_phys(page) + offset;
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}
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static void frv_dma_sync_single_for_device(struct device *dev,
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dma_addr_t dma_handle, size_t size,
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enum dma_data_direction direction)
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{
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flush_write_buffers();
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}
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static void frv_dma_sync_sg_for_device(struct device *dev,
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struct scatterlist *sg, int nelems,
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enum dma_data_direction direction)
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{
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flush_write_buffers();
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}
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static int frv_dma_supported(struct device *dev, u64 mask)
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{
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/*
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* we fall back to GFP_DMA when the mask isn't all 1s,
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* so we can't guarantee allocations that must be
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* within a tighter range than GFP_DMA..
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*/
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if (mask < 0x00ffffff)
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return 0;
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return 1;
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}
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struct dma_map_ops frv_dma_ops = {
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.alloc = frv_dma_alloc,
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.free = frv_dma_free,
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.map_page = frv_dma_map_page,
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.map_sg = frv_dma_map_sg,
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.sync_single_for_device = frv_dma_sync_single_for_device,
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.sync_sg_for_device = frv_dma_sync_sg_for_device,
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.dma_supported = frv_dma_supported,
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};
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EXPORT_SYMBOL(frv_dma_ops);
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