kernel/arch/nios2/mm/dma-mapping.c

   1 /*
   2  * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   3  * Copyright (C) 2009 Wind River Systems Inc
   4  *  Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
   5  *
   6  * Based on DMA code from MIPS.
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/mm.h>
  15 #include <linux/export.h>
  16 #include <linux/string.h>
  17 #include <linux/scatterlist.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/io.h>
  20 #include <linux/cache.h>
  21 #include <asm/cacheflush.h>
  22
  23
  24 void *dma_alloc_coherent(struct device *dev, size_t size,
  25                             dma_addr_t *dma_handle, gfp_t gfp)
  26 {
  27         void *ret;
  28
  29         /* ignore region specifiers */
  30         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  31
  32         /* optimized page clearing */
  33         gfp |= __GFP_ZERO;
  34
  35         if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
  36                 gfp |= GFP_DMA;
  37
  38         ret = (void *) __get_free_pages(gfp, get_order(size));
  39         if (ret != NULL) {
  40                 *dma_handle = virt_to_phys(ret);
  41                 flush_dcache_range((unsigned long) ret,
  42                         (unsigned long) ret + size);
  43                 ret = UNCAC_ADDR(ret);
  44         }
  45
  46         return ret;
  47 }
  48 EXPORT_SYMBOL(dma_alloc_coherent);
  49
  50 void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
  51                         dma_addr_t dma_handle)
  52 {
  53         unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
  54
  55         free_pages(addr, get_order(size));
  56 }
  57 EXPORT_SYMBOL(dma_free_coherent);
  58
  59 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  60                 enum dma_data_direction direction)
  61 {
  62         int i;
  63
  64         BUG_ON(!valid_dma_direction(direction));
  65
  66         for_each_sg(sg, sg, nents, i) {
  67                 void *addr;
  68
  69                 addr = sg_virt(sg);
  70                 if (addr) {
  71                         __dma_sync_for_device(addr, sg->length, direction);
  72                         sg->dma_address = sg_phys(sg);
  73                 }
  74         }
  75
  76         return nents;
  77 }
  78 EXPORT_SYMBOL(dma_map_sg);
  79
  80 dma_addr_t dma_map_page(struct device *dev, struct page *page,
  81                         unsigned long offset, size_t size,
  82                         enum dma_data_direction direction)
  83 {
  84         void *addr;
  85
  86         BUG_ON(!valid_dma_direction(direction));
  87
  88         addr = page_address(page) + offset;
  89         __dma_sync_for_device(addr, size, direction);
  90
  91         return page_to_phys(page) + offset;
  92 }
  93 EXPORT_SYMBOL(dma_map_page);
  94
  95 void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
  96                     enum dma_data_direction direction)
  97 {
  98         BUG_ON(!valid_dma_direction(direction));
  99
 100         __dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
 101 }
 102 EXPORT_SYMBOL(dma_unmap_page);
 103
 104 void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
 105                   enum dma_data_direction direction)
 106 {
 107         void *addr;
 108         int i;
 109
 110         BUG_ON(!valid_dma_direction(direction));
 111
 112         if (direction == DMA_TO_DEVICE)
 113                 return;
 114
 115         for_each_sg(sg, sg, nhwentries, i) {
 116                 addr = sg_virt(sg);
 117                 if (addr)
 118                         __dma_sync_for_cpu(addr, sg->length, direction);
 119         }
 120 }
 121 EXPORT_SYMBOL(dma_unmap_sg);
 122
 123 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 124                              size_t size, enum dma_data_direction direction)
 125 {
 126         BUG_ON(!valid_dma_direction(direction));
 127
 128         __dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
 129 }
 130 EXPORT_SYMBOL(dma_sync_single_for_cpu);
 131
 132 void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
 133                                 size_t size, enum dma_data_direction direction)
 134 {
 135         BUG_ON(!valid_dma_direction(direction));
 136
 137         __dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
 138 }
 139 EXPORT_SYMBOL(dma_sync_single_for_device);
 140
 141 void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
 142                                         unsigned long offset, size_t size,
 143                                         enum dma_data_direction direction)
 144 {
 145         BUG_ON(!valid_dma_direction(direction));
 146
 147         __dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
 148 }
 149 EXPORT_SYMBOL(dma_sync_single_range_for_cpu);
 150
 151 void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
 152                                         unsigned long offset, size_t size,
 153                                         enum dma_data_direction direction)
 154 {
 155         BUG_ON(!valid_dma_direction(direction));
 156
 157         __dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
 158 }
 159 EXPORT_SYMBOL(dma_sync_single_range_for_device);
 160
 161 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
 162                          enum dma_data_direction direction)
 163 {
 164         int i;
 165
 166         BUG_ON(!valid_dma_direction(direction));
 167
 168         /* Make sure that gcc doesn't leave the empty loop body.  */
 169         for_each_sg(sg, sg, nelems, i)
 170                 __dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
 171 }
 172 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
 173
 174 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 175                                 int nelems, enum dma_data_direction direction)
 176 {
 177         int i;
 178
 179         BUG_ON(!valid_dma_direction(direction));
 180
 181         /* Make sure that gcc doesn't leave the empty loop body.  */
 182         for_each_sg(sg, sg, nelems, i)
 183                 __dma_sync_for_device(sg_virt(sg), sg->length, direction);
 184
 185 }
 186 EXPORT_SYMBOL(dma_sync_sg_for_device);