LXR linux/arch/frv/mb93090-mb00/pci-dma.c

   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, int 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
  31void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
  32{
  33        consistent_free(vaddr);
  34}
  35
  36/*
  37 * Map a single buffer of the indicated size for DMA in streaming mode.
  38 * The 32-bit bus address to use is returned.
  39 *
  40 * Once the device is given the dma address, the device owns this memory
  41 * until either pci_unmap_single or pci_dma_sync_single is performed.
  42 */
  43dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  44                          enum dma_data_direction direction)
  45{
  46        if (direction == DMA_NONE)
  47                BUG();
  48
  49        frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
  50
  51        return virt_to_bus(ptr);
  52}
  53
  54/*
  55 * Map a set of buffers described by scatterlist in streaming
  56 * mode for DMA.  This is the scather-gather version of the
  57 * above pci_map_single interface.  Here the scatter gather list
  58 * elements are each tagged with the appropriate dma address
  59 * and length.  They are obtained via sg_dma_{address,length}(SG).
  60 *
  61 * NOTE: An implementation may be able to use a smaller number of
  62 *       DMA address/length pairs than there are SG table elements.
  63 *       (for example via virtual mapping capabilities)
  64 *       The routine returns the number of addr/length pairs actually
  65 *       used, at most nents.
  66 *
  67 * Device ownership issues as mentioned above for pci_map_single are
  68 * the same here.
  69 */
  70int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  71               enum dma_data_direction direction)
  72{
  73        unsigned long dampr2;
  74        void *vaddr;
  75        int i;
  76
  77        if (direction == DMA_NONE)
  78                BUG();
  79
  80        dampr2 = __get_DAMPR(2);
  81
  82        for (i = 0; i < nents; i++) {
  83                vaddr = kmap_atomic(sg[i].page, __KM_CACHE);
  84
  85                frv_dcache_writeback((unsigned long) vaddr,
  86                                     (unsigned long) vaddr + PAGE_SIZE);
  87
  88        }
  89
  90        kunmap_atomic(vaddr, __KM_CACHE);
  91        if (dampr2) {
  92                __set_DAMPR(2, dampr2);
  93                __set_IAMPR(2, dampr2);
  94        }
  95
  96        return nents;
  97}
  98
  99dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 100                        size_t size, enum dma_data_direction direction)
 101{
 102        BUG_ON(direction == DMA_NONE);
 103        flush_dcache_page(page);
 104        return (dma_addr_t) page_to_phys(page) + offset;
 105}
 106