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                 unsigned long attrs)
  42 {
  43         dma_addr_t handle = virt_to_phys(page_address(page) + offset);
  44
  45         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
  46                 c6x_dma_sync(handle, size, dir);
  47
  48         return handle;
  49 }
  50
  51 static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
  52                 size_t size, enum dma_data_direction dir, unsigned long attrs)
  53 {
  54         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
  55                 c6x_dma_sync(handle, size, dir);
  56 }
  57
  58 static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
  59                 int nents, enum dma_data_direction dir, unsigned long attrs)
  60 {
  61         struct scatterlist *sg;
  62         int i;
  63
  64         for_each_sg(sglist, sg, nents, i) {
  65                 sg->dma_address = sg_phys(sg);
  66                 if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
  67                         c6x_dma_sync(sg->dma_address, sg->length, dir);
  68         }
  69
  70         return nents;
  71 }
  72
  73 static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
  74                   int nents, enum dma_data_direction dir, unsigned long attrs)
  75 {
  76         struct scatterlist *sg;
  77         int i;
  78
  79         if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
  80                 return;
  81
  82         for_each_sg(sglist, sg, nents, i)
  83                 c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
  84 }
  85
  86 static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
  87                 size_t size, enum dma_data_direction dir)
  88 {
  89         c6x_dma_sync(handle, size, dir);
  90
  91 }
  92
  93 static void c6x_dma_sync_single_for_device(struct device *dev,
  94                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
  95 {
  96         c6x_dma_sync(handle, size, dir);
  97
  98 }
  99
 100 static void c6x_dma_sync_sg_for_cpu(struct device *dev,
 101                 struct scatterlist *sglist, int nents,
 102                 enum dma_data_direction dir)
 103 {
 104         struct scatterlist *sg;
 105         int i;
 106
 107         for_each_sg(sglist, sg, nents, i)
 108                 c6x_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
 109                                         sg->length, dir);
 110
 111 }
 112
 113 static void c6x_dma_sync_sg_for_device(struct device *dev,
 114                 struct scatterlist *sglist, int nents,
 115                 enum dma_data_direction dir)
 116 {
 117         struct scatterlist *sg;
 118         int i;
 119
 120         for_each_sg(sglist, sg, nents, i)
 121                 c6x_dma_sync_single_for_device(dev, sg_dma_address(sg),
 122                                            sg->length, dir);
 123
 124 }
 125
 126 const struct dma_map_ops c6x_dma_ops = {
 127         .alloc                  = c6x_dma_alloc,
 128         .free                   = c6x_dma_free,
 129         .map_page               = c6x_dma_map_page,
 130         .unmap_page             = c6x_dma_unmap_page,
 131         .map_sg                 = c6x_dma_map_sg,
 132         .unmap_sg               = c6x_dma_unmap_sg,
 133         .sync_single_for_device = c6x_dma_sync_single_for_device,
 134         .sync_single_for_cpu    = c6x_dma_sync_single_for_cpu,
 135         .sync_sg_for_device     = c6x_dma_sync_sg_for_device,
 136         .sync_sg_for_cpu        = c6x_dma_sync_sg_for_cpu,
 137 };
 138 EXPORT_SYMBOL(c6x_dma_ops);
 139
 140 /* Number of entries preallocated for DMA-API debugging */
 141 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 142
 143 static int __init dma_init(void)
 144 {
 145         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 146
 147         return 0;
 148 }
 149 fs_initcall(dma_init);