kernel/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 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  40                           enum dma_data_direction dir)
  41 {
  42         dma_addr_t addr = virt_to_phys(ptr);
  43
  44         c6x_dma_sync(addr, size, dir);
  45
  46         debug_dma_map_page(dev, virt_to_page(ptr),
  47                            (unsigned long)ptr & ~PAGE_MASK, size,
  48                            dir, addr, true);
  49         return addr;
  50 }
  51 EXPORT_SYMBOL(dma_map_single);
  52
  53
  54 void dma_unmap_single(struct device *dev, dma_addr_t handle,
  55                       size_t size, enum dma_data_direction dir)
  56 {
  57         c6x_dma_sync(handle, size, dir);
  58
  59         debug_dma_unmap_page(dev, handle, size, dir, true);
  60 }
  61 EXPORT_SYMBOL(dma_unmap_single);
  62
  63
  64 int dma_map_sg(struct device *dev, struct scatterlist *sglist,
  65                int nents, enum dma_data_direction dir)
  66 {
  67         struct scatterlist *sg;
  68         int i;
  69
  70         for_each_sg(sglist, sg, nents, i)
  71                 sg->dma_address = dma_map_single(dev, sg_virt(sg), sg->length,
  72                                                  dir);
  73
  74         debug_dma_map_sg(dev, sglist, nents, nents, dir);
  75
  76         return nents;
  77 }
  78 EXPORT_SYMBOL(dma_map_sg);
  79
  80
  81 void dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
  82                   int nents, enum dma_data_direction dir)
  83 {
  84         struct scatterlist *sg;
  85         int i;
  86
  87         for_each_sg(sglist, sg, nents, i)
  88                 dma_unmap_single(dev, sg_dma_address(sg), sg->length, dir);
  89
  90         debug_dma_unmap_sg(dev, sglist, nents, dir);
  91 }
  92 EXPORT_SYMBOL(dma_unmap_sg);
  93
  94 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
  95                              size_t size, enum dma_data_direction dir)
  96 {
  97         c6x_dma_sync(handle, size, dir);
  98
  99         debug_dma_sync_single_for_cpu(dev, handle, size, dir);
 100 }
 101 EXPORT_SYMBOL(dma_sync_single_for_cpu);
 102
 103
 104 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
 105                                 size_t size, enum dma_data_direction dir)
 106 {
 107         c6x_dma_sync(handle, size, dir);
 108
 109         debug_dma_sync_single_for_device(dev, handle, size, dir);
 110 }
 111 EXPORT_SYMBOL(dma_sync_single_for_device);
 112
 113
 114 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist,
 115                          int nents, enum dma_data_direction dir)
 116 {
 117         struct scatterlist *sg;
 118         int i;
 119
 120         for_each_sg(sglist, sg, nents, i)
 121                 dma_sync_single_for_cpu(dev, sg_dma_address(sg),
 122                                         sg->length, dir);
 123
 124         debug_dma_sync_sg_for_cpu(dev, sglist, nents, dir);
 125 }
 126 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 127
 128
 129 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
 130                             int nents, enum dma_data_direction dir)
 131 {
 132         struct scatterlist *sg;
 133         int i;
 134
 135         for_each_sg(sglist, sg, nents, i)
 136                 dma_sync_single_for_device(dev, sg_dma_address(sg),
 137                                            sg->length, dir);
 138
 139         debug_dma_sync_sg_for_device(dev, sglist, nents, dir);
 140 }
 141 EXPORT_SYMBOL(dma_sync_sg_for_device);
 142
 143
 144 /* Number of entries preallocated for DMA-API debugging */
 145 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 146
 147 static int __init dma_init(void)
 148 {
 149         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 150
 151         return 0;
 152 }
 153 fs_initcall(dma_init);