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/dma-mapping.h>
  14#include <linux/list.h>
  15#include <linux/pci.h>
  16#include <linux/export.h>
  17#include <linux/highmem.h>
  18#include <linux/scatterlist.h>
  19#include <asm/io.h>
  20
  21static void *frv_dma_alloc(struct device *hwdev, size_t size,
  22                dma_addr_t *dma_handle, gfp_t gfp,
  23                struct dma_attrs *attrs)
  24{
  25        void *ret;
  26
  27        ret = consistent_alloc(gfp, size, dma_handle);
  28        if (ret)
  29                memset(ret, 0, size);
  30
  31        return ret;
  32}
  33
  34static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
  35                dma_addr_t dma_handle, struct dma_attrs *attrs)
  36{
  37        consistent_free(vaddr);
  38}
  39
  40static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
  41                int nents, enum dma_data_direction direction,
  42                struct dma_attrs *attrs)
  43{
  44        unsigned long dampr2;
  45        void *vaddr;
  46        int i;
  47        struct scatterlist *sg;
  48
  49        BUG_ON(direction == DMA_NONE);
  50
  51        dampr2 = __get_DAMPR(2);
  52
  53        for_each_sg(sglist, sg, nents, i) {
  54                vaddr = kmap_atomic_primary(sg_page(sg));
  55
  56                frv_dcache_writeback((unsigned long) vaddr,
  57                                     (unsigned long) vaddr + PAGE_SIZE);
  58
  59        }
  60
  61        kunmap_atomic_primary(vaddr);
  62        if (dampr2) {
  63                __set_DAMPR(2, dampr2);
  64                __set_IAMPR(2, dampr2);
  65        }
  66
  67        return nents;
  68}
  69
  70static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
  71                unsigned long offset, size_t size,
  72                enum dma_data_direction direction, struct dma_attrs *attrs)
  73{
  74        flush_dcache_page(page);
  75        return (dma_addr_t) page_to_phys(page) + offset;
  76}
  77
  78static void frv_dma_sync_single_for_device(struct device *dev,
  79                dma_addr_t dma_handle, size_t size,
  80                enum dma_data_direction direction)
  81{
  82        flush_write_buffers();
  83}
  84
  85static void frv_dma_sync_sg_for_device(struct device *dev,
  86                struct scatterlist *sg, int nelems,
  87                enum dma_data_direction direction)
  88{
  89        flush_write_buffers();
  90}
  91
  92
  93static int frv_dma_supported(struct device *dev, u64 mask)
  94{
  95        /*
  96         * we fall back to GFP_DMA when the mask isn't all 1s,
  97         * so we can't guarantee allocations that must be
  98         * within a tighter range than GFP_DMA..
  99         */
 100        if (mask < 0x00ffffff)
 101                return 0;
 102        return 1;
 103}
 104
 105struct dma_map_ops frv_dma_ops = {
 106        .alloc                  = frv_dma_alloc,
 107        .free                   = frv_dma_free,
 108        .map_page               = frv_dma_map_page,
 109        .map_sg                 = frv_dma_map_sg,
 110        .sync_single_for_device = frv_dma_sync_single_for_device,
 111        .sync_sg_for_device     = frv_dma_sync_sg_for_device,
 112        .dma_supported          = frv_dma_supported,
 113};
 114EXPORT_SYMBOL(frv_dma_ops);
 115