arch/sh/boards/overdrive/pcidma.c

   1 /*
   2  * Copyright (C) 2000 David J. Mckay (david.mckay@st.com)
   3  *
   4  * May be copied or modified under the terms of the GNU General Public
   5  * License.  See linux/COPYING for more information.
   6  *
   7  * Dynamic DMA mapping support.
   8  *
   9  * On the overdrive, we can only DMA from memory behind the PCI bus!
  10  * this means that all DMA'able memory must come from there.
  11  * this restriction will not apply to later boards.
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/mm.h>
  16 #include <linux/string.h>
  17 #include <linux/pci.h>
  18 #include <asm/io.h>
  19
  20 void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
  21                            dma_addr_t * dma_handle)
  22 {
  23         void *ret;
  24         int gfp = GFP_ATOMIC;
  25
  26         printk("BUG: pci_alloc_consistent() called - not yet supported\n");
  27         /* We ALWAYS need DMA memory on the overdrive hardware,
  28          * due to it's extreme weirdness
  29          * Need to flush the cache here as well, since the memory
  30          * can still be seen through the cache!
  31          */
  32         gfp |= GFP_DMA;
  33         ret = (void *) __get_free_pages(gfp, get_order(size));
  34
  35         if (ret != NULL) {
  36                 memset(ret, 0, size);
  37                 *dma_handle = virt_to_bus(ret);
  38         }
  39         return ret;
  40 }
  41
  42 void pci_free_consistent(struct pci_dev *hwdev, size_t size,
  43                          void *vaddr, dma_addr_t dma_handle)
  44 {
  45         free_pages((unsigned long) vaddr, get_order(size));
  46 }