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
  21 static 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
  34 static 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
  40 static 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
  70 static 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
  78 static 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
  85 static 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
  93 static 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
 105 struct 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 };
 114 EXPORT_SYMBOL(frv_dma_ops);