arch/m68k/kernel/dma.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 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
  20
  21 static void *m68k_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
  22                 gfp_t flag, struct dma_attrs *attrs)
  23 {
  24         struct page *page, **map;
  25         pgprot_t pgprot;
  26         void *addr;
  27         int i, order;
  28
  29         pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
  30
  31         size = PAGE_ALIGN(size);
  32         order = get_order(size);
  33
  34         page = alloc_pages(flag, order);
  35         if (!page)
  36                 return NULL;
  37
  38         *handle = page_to_phys(page);
  39         map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
  40         if (!map) {
  41                 __free_pages(page, order);
  42                 return NULL;
  43         }
  44         split_page(page, order);
  45
  46         order = 1 << order;
  47         size >>= PAGE_SHIFT;
  48         map[0] = page;
  49         for (i = 1; i < size; i++)
  50                 map[i] = page + i;
  51         for (; i < order; i++)
  52                 __free_page(page + i);
  53         pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
  54         if (CPU_IS_040_OR_060)
  55                 pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
  56         else
  57                 pgprot_val(pgprot) |= _PAGE_NOCACHE030;
  58         addr = vmap(map, size, VM_MAP, pgprot);
  59         kfree(map);
  60
  61         return addr;
  62 }
  63
  64 static void m68k_dma_free(struct device *dev, size_t size, void *addr,
  65                 dma_addr_t handle, struct dma_attrs *attrs)
  66 {
  67         pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
  68         vfree(addr);
  69 }
  70
  71 #else
  72
  73 #include <asm/cacheflush.h>
  74
  75 static void *m68k_dma_alloc(struct device *dev, size_t size,
  76                 dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
  77 {
  78         void *ret;
  79         /* ignore region specifiers */
  80         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  81
  82         if (dev == NULL || (*dev->dma_mask < 0xffffffff))
  83                 gfp |= GFP_DMA;
  84         ret = (void *)__get_free_pages(gfp, get_order(size));
  85
  86         if (ret != NULL) {
  87                 memset(ret, 0, size);
  88                 *dma_handle = virt_to_phys(ret);
  89         }
  90         return ret;
  91 }
  92
  93 static void m68k_dma_free(struct device *dev, size_t size, void *vaddr,
  94                 dma_addr_t dma_handle, struct dma_attrs *attrs)
  95 {
  96         free_pages((unsigned long)vaddr, get_order(size));
  97 }
  98
  99 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
 100
 101 static void m68k_dma_sync_single_for_device(struct device *dev,
 102                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 103 {
 104         switch (dir) {
 105         case DMA_BIDIRECTIONAL:
 106         case DMA_TO_DEVICE:
 107                 cache_push(handle, size);
 108                 break;
 109         case DMA_FROM_DEVICE:
 110                 cache_clear(handle, size);
 111                 break;
 112         default:
 113                 if (printk_ratelimit())
 114                         printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
 115                 break;
 116         }
 117 }
 118
 119 static void m68k_dma_sync_sg_for_device(struct device *dev,
 120                 struct scatterlist *sglist, int nents, enum dma_data_direction dir)
 121 {
 122         int i;
 123         struct scatterlist *sg;
 124
 125         for_each_sg(sglist, sg, nents, i) {
 126                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 127                                            dir);
 128         }
 129 }
 130
 131 static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
 132                 unsigned long offset, size_t size, enum dma_data_direction dir,
 133                 struct dma_attrs *attrs)
 134 {
 135         dma_addr_t handle = page_to_phys(page) + offset;
 136
 137         dma_sync_single_for_device(dev, handle, size, dir);
 138         return handle;
 139 }
 140
 141 static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 142                 int nents, enum dma_data_direction dir, struct dma_attrs *attrs)
 143 {
 144         int i;
 145         struct scatterlist *sg;
 146
 147         for_each_sg(sglist, sg, nents, i) {
 148                 sg->dma_address = sg_phys(sg);
 149                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 150                                            dir);
 151         }
 152         return nents;
 153 }
 154
 155 struct dma_map_ops m68k_dma_ops = {
 156         .alloc                  = m68k_dma_alloc,
 157         .free                   = m68k_dma_free,
 158         .map_page               = m68k_dma_map_page,
 159         .map_sg                 = m68k_dma_map_sg,
 160         .sync_single_for_device = m68k_dma_sync_single_for_device,
 161         .sync_sg_for_device     = m68k_dma_sync_sg_for_device,
 162 };
 163 EXPORT_SYMBOL(m68k_dma_ops);