arch/sh64/kernel/pci-dma.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 <asm/io.h>
  15
  16 void *consistent_alloc(struct pci_dev *hwdev, size_t size,
  17                            dma_addr_t *dma_handle)
  18 {
  19         void *ret;
  20         int gfp = GFP_ATOMIC;
  21         void *vp;
  22
  23         if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
  24                 gfp |= GFP_DMA;
  25
  26         ret = (void *)__get_free_pages(gfp, get_order(size));
  27
  28         /* now call our friend ioremap_nocache to give us an uncached area */
  29         vp = ioremap_nocache(virt_to_phys(ret), size);
  30
  31         if (vp != NULL) {
  32                 memset(vp, 0, size);
  33                 *dma_handle = virt_to_bus(ret);
  34                 dma_cache_wback_inv((unsigned long)ret, size);
  35         }
  36
  37         return vp;
  38 }
  39
  40 void consistent_free(struct pci_dev *hwdev, size_t size,
  41                          void *vaddr, dma_addr_t dma_handle)
  42 {
  43         void *alloc;
  44
  45         alloc = bus_to_virt((unsigned long)dma_handle);
  46         free_pages((unsigned long)alloc, get_order(size));
  47
  48         iounmap(vaddr);
  49 }
  50