1/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs 2 * 3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12#include <linux/types.h> 13#include <linux/slab.h> 14#include <linux/dma-mapping.h> 15#include <linux/list.h> 16#include <linux/pci.h> 17#include <linux/highmem.h> 18#include <asm/io.h> 19 20void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) 21{ 22 void *ret; 23 24 ret = consistent_alloc(gfp, size, dma_handle); 25 if (ret) 26 memset(ret, 0, size); 27 28 return ret; 29} 30 31EXPORT_SYMBOL(dma_alloc_coherent); 32 33void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle) 34{ 35 consistent_free(vaddr); 36} 37 38EXPORT_SYMBOL(dma_free_coherent); 39 40/* 41 * Map a single buffer of the indicated size for DMA in streaming mode. 42 * The 32-bit bus address to use is returned. 43 * 44 * Once the device is given the dma address, the device owns this memory 45 * until either pci_unmap_single or pci_dma_sync_single is performed. 46 */ 47dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size, 48 enum dma_data_direction direction) 49{ 50 if (direction == DMA_NONE) 51 BUG(); 52 53 frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size); 54 55 return virt_to_bus(ptr); 56} 57 58EXPORT_SYMBOL(dma_map_single); 59 60/* 61 * Map a set of buffers described by scatterlist in streaming 62 * mode for DMA. This is the scather-gather version of the 63 * above pci_map_single interface. Here the scatter gather list 64 * elements are each tagged with the appropriate dma address 65 * and length. They are obtained via sg_dma_{address,length}(SG). 66 * 67 * NOTE: An implementation may be able to use a smaller number of 68 * DMA address/length pairs than there are SG table elements. 69 * (for example via virtual mapping capabilities) 70 * The routine returns the number of addr/length pairs actually 71 * used, at most nents. 72 * 73 * Device ownership issues as mentioned above for pci_map_single are 74 * the same here. 75 */ 76int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, 77 enum dma_data_direction direction) 78{ 79 unsigned long dampr2; 80 void *vaddr; 81 int i; 82 83 if (direction == DMA_NONE) 84 BUG(); 85 86 dampr2 = __get_DAMPR(2); 87 88 for (i = 0; i < nents; i++) { 89 vaddr = kmap_atomic(sg[i].page, __KM_CACHE); 90 91 frv_dcache_writeback((unsigned long) vaddr, 92 (unsigned long) vaddr + PAGE_SIZE); 93 94 } 95 96 kunmap_atomic(vaddr, __KM_CACHE); 97 if (dampr2) { 98 __set_DAMPR(2, dampr2); 99 __set_IAMPR(2, dampr2); 100 } 101 102 return nents; 103} 104 105EXPORT_SYMBOL(dma_map_sg); 106 107dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, 108 size_t size, enum dma_data_direction direction) 109{ 110 BUG_ON(direction == DMA_NONE); 111 flush_dcache_page(page); 112 return (dma_addr_t) page_to_phys(page) + offset; 113} 114 115EXPORT_SYMBOL(dma_map_page); 116