arch/sh64/mm/consistent.c

   1 /*
   2  * Copyright (C) 2001 David J. Mckay (david.mckay@st.com)
   3  * Copyright (C) 2003 Paul Mundt (lethal@linux-sh.org)
   4  *
   5  * May be copied or modified under the terms of the GNU General Public
   6  * License.  See linux/COPYING for more information.
   7  *
   8  * Dynamic DMA mapping support.
   9  */
  10 #include <linux/types.h>
  11 #include <linux/mm.h>
  12 #include <linux/string.h>
  13 #include <linux/pci.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/module.h>
  16 #include <asm/io.h>
  17
  18 void *consistent_alloc(struct pci_dev *hwdev, size_t size,
  19                            dma_addr_t *dma_handle)
  20 {
  21         void *ret;
  22         int gfp = GFP_ATOMIC;
  23         void *vp;
  24
  25         if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
  26                 gfp |= GFP_DMA;
  27
  28         ret = (void *)__get_free_pages(gfp, get_order(size));
  29
  30         /* now call our friend ioremap_nocache to give us an uncached area */
  31         vp = ioremap_nocache(virt_to_phys(ret), size);
  32
  33         if (vp != NULL) {
  34                 memset(vp, 0, size);
  35                 *dma_handle = virt_to_phys(ret);
  36                 dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
  37         }
  38
  39         return vp;
  40 }
  41 EXPORT_SYMBOL(consistent_alloc);
  42
  43 void consistent_free(struct pci_dev *hwdev, size_t size,
  44                          void *vaddr, dma_addr_t dma_handle)
  45 {
  46         void *alloc;
  47
  48         alloc = phys_to_virt((unsigned long)dma_handle);
  49         free_pages((unsigned long)alloc, get_order(size));
  50
  51         iounmap(vaddr);
  52 }
  53 EXPORT_SYMBOL(consistent_free);