arch/m68k/kernel/dma_mm.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file COPYING in the main directory of this archive
   4  * for more details.
   5  */
   6
   7 #undef DEBUG
   8
   9 #include <linux/dma-mapping.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/scatterlist.h>
  13 #include <linux/slab.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/export.h>
  16
  17 #include <asm/pgalloc.h>
  18
  19 void *dma_alloc_coherent(struct device *dev, size_t size,
  20                          dma_addr_t *handle, gfp_t flag)
  21 {
  22         struct page *page, **map;
  23         pgprot_t pgprot;
  24         void *addr;
  25         int i, order;
  26
  27         pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
  28
  29         size = PAGE_ALIGN(size);
  30         order = get_order(size);
  31
  32         page = alloc_pages(flag, order);
  33         if (!page)
  34                 return NULL;
  35
  36         *handle = page_to_phys(page);
  37         map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
  38         if (!map) {
  39                 __free_pages(page, order);
  40                 return NULL;
  41         }
  42         split_page(page, order);
  43
  44         order = 1 << order;
  45         size >>= PAGE_SHIFT;
  46         map[0] = page;
  47         for (i = 1; i < size; i++)
  48                 map[i] = page + i;
  49         for (; i < order; i++)
  50                 __free_page(page + i);
  51         pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
  52         if (CPU_IS_040_OR_060)
  53                 pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
  54         else
  55                 pgprot_val(pgprot) |= _PAGE_NOCACHE030;
  56         addr = vmap(map, size, VM_MAP, pgprot);
  57         kfree(map);
  58
  59         return addr;
  60 }
  61 EXPORT_SYMBOL(dma_alloc_coherent);
  62
  63 void dma_free_coherent(struct device *dev, size_t size,
  64                        void *addr, dma_addr_t handle)
  65 {
  66         pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
  67         vfree(addr);
  68 }
  69 EXPORT_SYMBOL(dma_free_coherent);
  70
  71 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
  72                                 size_t size, enum dma_data_direction dir)
  73 {
  74         switch (dir) {
  75         case DMA_TO_DEVICE:
  76                 cache_push(handle, size);
  77                 break;
  78         case DMA_FROM_DEVICE:
  79                 cache_clear(handle, size);
  80                 break;
  81         default:
  82                 if (printk_ratelimit())
  83                         printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
  84                 break;
  85         }
  86 }
  87 EXPORT_SYMBOL(dma_sync_single_for_device);
  88
  89 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
  90                             enum dma_data_direction dir)
  91 {
  92         int i;
  93
  94         for (i = 0; i < nents; sg++, i++)
  95                 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
  96 }
  97 EXPORT_SYMBOL(dma_sync_sg_for_device);
  98
  99 dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
 100                           enum dma_data_direction dir)
 101 {
 102         dma_addr_t handle = virt_to_bus(addr);
 103
 104         dma_sync_single_for_device(dev, handle, size, dir);
 105         return handle;
 106 }
 107 EXPORT_SYMBOL(dma_map_single);
 108
 109 dma_addr_t dma_map_page(struct device *dev, struct page *page,
 110                         unsigned long offset, size_t size,
 111                         enum dma_data_direction dir)
 112 {
 113         dma_addr_t handle = page_to_phys(page) + offset;
 114
 115         dma_sync_single_for_device(dev, handle, size, dir);
 116         return handle;
 117 }
 118 EXPORT_SYMBOL(dma_map_page);
 119
 120 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 121                enum dma_data_direction dir)
 122 {
 123         int i;
 124
 125         for (i = 0; i < nents; sg++, i++) {
 126                 sg->dma_address = sg_phys(sg);
 127                 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
 128         }
 129         return nents;
 130 }
 131 EXPORT_SYMBOL(dma_map_sg);