LXR linux/arch/cris/arch-v32/drivers/pci/dma.c

   1/*
   2 * Dynamic DMA mapping support.
   3 *
   4 * On cris there is no hardware dynamic DMA address translation,
   5 * so consistent alloc/free are merely page allocation/freeing.
   6 * The rest of the dynamic DMA mapping interface is implemented
   7 * in asm/pci.h.
   8 *
   9 * Borrowed from i386.
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/mm.h>
  14#include <linux/string.h>
  15#include <linux/pci.h>
  16#include <linux/gfp.h>
  17#include <asm/io.h>
  18
  19static void *v32_dma_alloc(struct device *dev, size_t size,
  20                dma_addr_t *dma_handle, gfp_t gfp,  struct dma_attrs *attrs)
  21{
  22        void *ret;
  23
  24        /* ignore region specifiers */
  25        gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  26
  27        if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
  28                gfp |= GFP_DMA;
  29
  30        ret = (void *)__get_free_pages(gfp,  get_order(size));
  31
  32        if (ret != NULL) {
  33                memset(ret, 0, size);
  34                *dma_handle = virt_to_phys(ret);
  35        }
  36        return ret;
  37}
  38
  39static void v32_dma_free(struct device *dev, size_t size, void *vaddr,
  40                dma_addr_t dma_handle, struct dma_attrs *attrs)
  41{
  42        free_pages((unsigned long)vaddr, get_order(size));
  43}
  44
  45static inline dma_addr_t v32_dma_map_page(struct device *dev,
  46                struct page *page, unsigned long offset, size_t size,
  47                enum dma_data_direction direction,
  48                struct dma_attrs *attrs)
  49{
  50        return page_to_phys(page) + offset;
  51}
  52
  53static inline int v32_dma_map_sg(struct device *dev, struct scatterlist *sg,
  54                int nents, enum dma_data_direction direction,
  55                struct dma_attrs *attrs)
  56{
  57        printk("Map sg\n");
  58        return nents;
  59}
  60
  61static inline int v32_dma_supported(struct device *dev, u64 mask)
  62{
  63        /*
  64         * we fall back to GFP_DMA when the mask isn't all 1s,
  65         * so we can't guarantee allocations that must be
  66         * within a tighter range than GFP_DMA..
  67         */
  68        if (mask < 0x00ffffff)
  69                return 0;
  70        return 1;
  71}
  72
  73struct dma_map_ops v32_dma_ops = {
  74        .alloc                  = v32_dma_alloc,
  75        .free                   = v32_dma_free,
  76        .map_page               = v32_dma_map_page,
  77        .map_sg                 = v32_dma_map_sg,
  78        .dma_supported          = v32_dma_supported,
  79};
  80EXPORT_SYMBOL(v32_dma_ops);
  81