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/platform_device.h>
  13 #include <linux/scatterlist.h>
  14 #include <linux/slab.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/export.h>
  17
  18 #include <asm/pgalloc.h>
  19
  20 #if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
  21
  22 static void *m68k_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
  23                 gfp_t flag, unsigned long attrs)
  24 {
  25         struct page *page, **map;
  26         pgprot_t pgprot;
  27         void *addr;
  28         int i, order;
  29
  30         pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
  31
  32         size = PAGE_ALIGN(size);
  33         order = get_order(size);
  34
  35         page = alloc_pages(flag, order);
  36         if (!page)
  37                 return NULL;
  38
  39         *handle = page_to_phys(page);
  40         map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
  41         if (!map) {
  42                 __free_pages(page, order);
  43                 return NULL;
  44         }
  45         split_page(page, order);
  46
  47         order = 1 << order;
  48         size >>= PAGE_SHIFT;
  49         map[0] = page;
  50         for (i = 1; i < size; i++)
  51                 map[i] = page + i;
  52         for (; i < order; i++)
  53                 __free_page(page + i);
  54         pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
  55         if (CPU_IS_040_OR_060)
  56                 pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
  57         else
  58                 pgprot_val(pgprot) |= _PAGE_NOCACHE030;
  59         addr = vmap(map, size, VM_MAP, pgprot);
  60         kfree(map);
  61
  62         return addr;
  63 }
  64
  65 static void m68k_dma_free(struct device *dev, size_t size, void *addr,
  66                 dma_addr_t handle, unsigned long attrs)
  67 {
  68         pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
  69         vfree(addr);
  70 }
  71
  72 #else
  73
  74 #include <asm/cacheflush.h>
  75
  76 static void *m68k_dma_alloc(struct device *dev, size_t size,
  77                 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
  78 {
  79         void *ret;
  80
  81         if (dev == NULL || (*dev->dma_mask < 0xffffffff))
  82                 gfp |= GFP_DMA;
  83         ret = (void *)__get_free_pages(gfp, get_order(size));
  84
  85         if (ret != NULL) {
  86                 memset(ret, 0, size);
  87                 *dma_handle = virt_to_phys(ret);
  88         }
  89         return ret;
  90 }
  91
  92 static void m68k_dma_free(struct device *dev, size_t size, void *vaddr,
  93                 dma_addr_t dma_handle, unsigned long attrs)
  94 {
  95         free_pages((unsigned long)vaddr, get_order(size));
  96 }
  97
  98 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
  99
 100 static void m68k_dma_sync_single_for_device(struct device *dev,
 101                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 102 {
 103         switch (dir) {
 104         case DMA_BIDIRECTIONAL:
 105         case DMA_TO_DEVICE:
 106                 cache_push(handle, size);
 107                 break;
 108         case DMA_FROM_DEVICE:
 109                 cache_clear(handle, size);
 110                 break;
 111         default:
 112                 pr_err_ratelimited("dma_sync_single_for_device: unsupported dir %u\n",
 113                                    dir);
 114                 break;
 115         }
 116 }
 117
 118 static void m68k_dma_sync_sg_for_device(struct device *dev,
 119                 struct scatterlist *sglist, int nents, enum dma_data_direction dir)
 120 {
 121         int i;
 122         struct scatterlist *sg;
 123
 124         for_each_sg(sglist, sg, nents, i) {
 125                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 126                                            dir);
 127         }
 128 }
 129
 130 static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
 131                 unsigned long offset, size_t size, enum dma_data_direction dir,
 132                 unsigned long attrs)
 133 {
 134         dma_addr_t handle = page_to_phys(page) + offset;
 135
 136         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 137                 dma_sync_single_for_device(dev, handle, size, dir);
 138
 139         return handle;
 140 }
 141
 142 static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 143                 int nents, enum dma_data_direction dir, unsigned long attrs)
 144 {
 145         int i;
 146         struct scatterlist *sg;
 147
 148         for_each_sg(sglist, sg, nents, i) {
 149                 sg->dma_address = sg_phys(sg);
 150
 151                 if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
 152                         continue;
 153
 154                 dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 155                                            dir);
 156         }
 157         return nents;
 158 }
 159
 160 const struct dma_map_ops m68k_dma_ops = {
 161         .alloc                  = m68k_dma_alloc,
 162         .free                   = m68k_dma_free,
 163         .map_page               = m68k_dma_map_page,
 164         .map_sg                 = m68k_dma_map_sg,
 165         .sync_single_for_device = m68k_dma_sync_single_for_device,
 166         .sync_sg_for_device     = m68k_dma_sync_sg_for_device,
 167 };
 168 EXPORT_SYMBOL(m68k_dma_ops);
 169
 170 void arch_setup_pdev_archdata(struct platform_device *pdev)
 171 {
 172         if (pdev->dev.coherent_dma_mask == DMA_MASK_NONE &&
 173             pdev->dev.dma_mask == NULL) {
 174                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 175                 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
 176         }
 177 }