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, unsigned long 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, unsigned long 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, unsigned long attrs)
  77 {
  78         void *ret;
  79
  80         if (dev == NULL || (*dev->dma_mask < 0xffffffff))
  81                 gfp |= GFP_DMA;
  82         ret = (void *)__get_free_pages(gfp, get_order(size));
  83
  84         if (ret != NULL) {
  85                 memset(ret, 0, size);
  86                 *dma_handle = virt_to_phys(ret);
  87         }
  88         return ret;
  89 }
  90
  91 static void m68k_dma_free(struct device *dev, size_t size, void *vaddr,
  92                 dma_addr_t dma_handle, unsigned long attrs)
  93 {
  94         free_pages((unsigned long)vaddr, get_order(size));
  95 }
  96
  97 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
  98
  99 static void m68k_dma_sync_single_for_device(struct device *dev,
 100                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 101 {
 102         switch (dir) {
 103         case DMA_BIDIRECTIONAL:
 104         case DMA_TO_DEVICE:
 105                 cache_push(handle, size);
 106                 break;
 107         case DMA_FROM_DEVICE:
 108                 cache_clear(handle, size);
 109                 break;
 110         default:
 111                 pr_err_ratelimited("dma_sync_single_for_device: unsupported dir %u\n",
 112                                    dir);
 113                 break;
 114         }
 115 }
 116
 117 static void m68k_dma_sync_sg_for_device(struct device *dev,
 118                 struct scatterlist *sglist, int nents, enum dma_data_direction dir)
 119 {
 120         int i;
 121         struct scatterlist *sg;
 122
 123         for_each_sg(sglist, sg, nents, i) {
 124                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 125                                            dir);
 126         }
 127 }
 128
 129 static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
 130                 unsigned long offset, size_t size, enum dma_data_direction dir,
 131                 unsigned long attrs)
 132 {
 133         dma_addr_t handle = page_to_phys(page) + offset;
 134
 135         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 136                 dma_sync_single_for_device(dev, handle, size, dir);
 137
 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, unsigned long 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
 150                 if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 151                         continue;
 152
 153                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 154                                            dir);
 155         }
 156         return nents;
 157 }
 158
 159 const struct dma_map_ops m68k_dma_ops = {
 160         .alloc                  = m68k_dma_alloc,
 161         .free                   = m68k_dma_free,
 162         .map_page               = m68k_dma_map_page,
 163         .map_sg                 = m68k_dma_map_sg,
 164         .sync_single_for_device = m68k_dma_sync_single_for_device,
 165         .sync_sg_for_device     = m68k_dma_sync_sg_for_device,
 166 };
 167 EXPORT_SYMBOL(m68k_dma_ops);