arch/c6x/kernel/dma.c

   1 /*
   2  *  Copyright (C) 2011 Texas Instruments Incorporated
   3  *  Author: Mark Salter <msalter@redhat.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License version 2 as
   7  *  published by the Free Software Foundation.
   8  */
   9 #include <linux/module.h>
  10 #include <linux/dma-mapping.h>
  11 #include <linux/mm.h>
  12 #include <linux/mm_types.h>
  13 #include <linux/scatterlist.h>
  14
  15 #include <asm/cacheflush.h>
  16
  17 static void c6x_dma_sync(dma_addr_t handle, size_t size,
  18                          enum dma_data_direction dir)
  19 {
  20         unsigned long paddr = handle;
  21
  22         BUG_ON(!valid_dma_direction(dir));
  23
  24         switch (dir) {
  25         case DMA_FROM_DEVICE:
  26                 L2_cache_block_invalidate(paddr, paddr + size);
  27                 break;
  28         case DMA_TO_DEVICE:
  29                 L2_cache_block_writeback(paddr, paddr + size);
  30                 break;
  31         case DMA_BIDIRECTIONAL:
  32                 L2_cache_block_writeback_invalidate(paddr, paddr + size);
  33                 break;
  34         default:
  35                 break;
  36         }
  37 }
  38
  39 static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
  40                 unsigned long offset, size_t size, enum dma_data_direction dir,
  41                 struct dma_attrs *attrs)
  42 {
  43         dma_addr_t handle = virt_to_phys(page_address(page) + offset);
  44
  45         c6x_dma_sync(handle, size, dir);
  46         return handle;
  47 }
  48
  49 static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
  50                 size_t size, enum dma_data_direction dir, struct dma_attrs *attrs)
  51 {
  52         c6x_dma_sync(handle, size, dir);
  53 }
  54
  55 static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
  56                 int nents, enum dma_data_direction dir, struct dma_attrs *attrs)
  57 {
  58         struct scatterlist *sg;
  59         int i;
  60
  61         for_each_sg(sglist, sg, nents, i) {
  62                 sg->dma_address = sg_phys(sg);
  63                 c6x_dma_sync(sg->dma_address, sg->length, dir);
  64         }
  65
  66         return nents;
  67 }
  68
  69 static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
  70                   int nents, enum dma_data_direction dir,
  71                   struct dma_attrs *attrs)
  72 {
  73         struct scatterlist *sg;
  74         int i;
  75
  76         for_each_sg(sglist, sg, nents, i)
  77                 c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
  78
  79 }
  80
  81 static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
  82                 size_t size, enum dma_data_direction dir)
  83 {
  84         c6x_dma_sync(handle, size, dir);
  85
  86 }
  87
  88 static void c6x_dma_sync_single_for_device(struct device *dev,
  89                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
  90 {
  91         c6x_dma_sync(handle, size, dir);
  92
  93 }
  94
  95 static void c6x_dma_sync_sg_for_cpu(struct device *dev,
  96                 struct scatterlist *sglist, int nents,
  97                 enum dma_data_direction dir)
  98 {
  99         struct scatterlist *sg;
 100         int i;
 101
 102         for_each_sg(sglist, sg, nents, i)
 103                 c6x_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
 104                                         sg->length, dir);
 105
 106 }
 107
 108 static void c6x_dma_sync_sg_for_device(struct device *dev,
 109                 struct scatterlist *sglist, int nents,
 110                 enum dma_data_direction dir)
 111 {
 112         struct scatterlist *sg;
 113         int i;
 114
 115         for_each_sg(sglist, sg, nents, i)
 116                 c6x_dma_sync_single_for_device(dev, sg_dma_address(sg),
 117                                            sg->length, dir);
 118
 119 }
 120
 121 struct dma_map_ops c6x_dma_ops = {
 122         .alloc                  = c6x_dma_alloc,
 123         .free                   = c6x_dma_free,
 124         .map_page               = c6x_dma_map_page,
 125         .unmap_page             = c6x_dma_unmap_page,
 126         .map_sg                 = c6x_dma_map_sg,
 127         .unmap_sg               = c6x_dma_unmap_sg,
 128         .sync_single_for_device = c6x_dma_sync_single_for_device,
 129         .sync_single_for_cpu    = c6x_dma_sync_single_for_cpu,
 130         .sync_sg_for_device     = c6x_dma_sync_sg_for_device,
 131         .sync_sg_for_cpu        = c6x_dma_sync_sg_for_cpu,
 132 };
 133 EXPORT_SYMBOL(c6x_dma_ops);
 134
 135 /* Number of entries preallocated for DMA-API debugging */
 136 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 137
 138 static int __init dma_init(void)
 139 {
 140         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 141
 142         return 0;
 143 }
 144 fs_initcall(dma_init);