arch/mips/kernel/pci-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  * Copyright (C) 2000  Ani Joshi <ajoshi@unixbox.com>
   7  * Copyright (C) 2000, 2001  Ralf Baechle <ralf@gnu.org>
   8  * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
   9  */
  10 #include <linux/config.h>
  11 #include <linux/types.h>
  12 #include <linux/mm.h>
  13 #include <linux/module.h>
  14 #include <linux/string.h>
  15 #include <linux/pci.h>
  16
  17 #include <asm/io.h>
  18
  19 #ifndef UNCAC_BASE      /* Hack ... */
  20 #define UNCAC_BASE      0x9000000000000000UL
  21 #endif
  22
  23 void *dma_alloc_coherent(struct device *dev, size_t size,
  24                          dma_addr_t * dma_handle, int gfp)
  25 {
  26         void *ret;
  27         /* ignore region specifiers */
  28         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  29
  30         if (dev == NULL || (*dev->dma_mask < 0xffffffff))
  31                 gfp |= GFP_DMA;
  32         ret = (void *) __get_free_pages(gfp, get_order(size));
  33
  34         if (ret != NULL) {
  35                 memset(ret, 0, size);
  36 #if 0   /* Broken support for some platforms ...  */
  37                 if (hwdev)
  38                         bus = hwdev->bus;
  39                 *dma_handle = bus_to_baddr(bus, __pa(ret));
  40 #else
  41                 *dma_handle = virt_to_phys(ret);
  42 #endif
  43 #ifdef CONFIG_NONCOHERENT_IO
  44                 dma_cache_wback_inv((unsigned long) ret, size);
  45                 ret = UNCAC_ADDR(ret);
  46 #endif
  47         }
  48
  49         return ret;
  50 }
  51
  52 void dma_free_coherent(struct device *dev, size_t size,
  53                        void *vaddr, dma_addr_t dma_handle)
  54 {
  55         unsigned long addr = (unsigned long) vaddr;
  56
  57 #ifdef CONFIG_NONCOHERENT_IO
  58         addr = CAC_ADDR(addr);
  59 #endif
  60         free_pages(addr, get_order(size));
  61 }
  62
  63 EXPORT_SYMBOL(pci_alloc_consistent);
  64 EXPORT_SYMBOL(pci_free_consistent);