LXR linux/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
  17static 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
  39dma_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}
  51EXPORT_SYMBOL(dma_map_single);
  52
  53
  54void 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}
  61EXPORT_SYMBOL(dma_unmap_single);
  62
  63
  64int 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}
  78EXPORT_SYMBOL(dma_map_sg);
  79
  80
  81void 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}
  92EXPORT_SYMBOL(dma_unmap_sg);
  93
  94void 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}
 101EXPORT_SYMBOL(dma_sync_single_for_cpu);
 102
 103
 104void 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}
 111EXPORT_SYMBOL(dma_sync_single_for_device);
 112
 113
 114void 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}
 126EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 127
 128
 129void 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}
 141EXPORT_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
 147static int __init dma_init(void)
 148{
 149        dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 150
 151        return 0;
 152}
 153fs_initcall(dma_init);
 154