arch/frv/mb93090-mb00/pci-dma.c

   1 /* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/slab.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/list.h>
  16 #include <linux/pci.h>
  17 #include <linux/highmem.h>
  18 #include <linux/scatterlist.h>
  19 #include <asm/io.h>
  20
  21 void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
  22 {
  23         void *ret;
  24
  25         ret = consistent_alloc(gfp, size, dma_handle);
  26         if (ret)
  27                 memset(ret, 0, size);
  28
  29         return ret;
  30 }
  31
  32 EXPORT_SYMBOL(dma_alloc_coherent);
  33
  34 void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
  35 {
  36         consistent_free(vaddr);
  37 }
  38
  39 EXPORT_SYMBOL(dma_free_coherent);
  40
  41 /*
  42  * Map a single buffer of the indicated size for DMA in streaming mode.
  43  * The 32-bit bus address to use is returned.
  44  *
  45  * Once the device is given the dma address, the device owns this memory
  46  * until either pci_unmap_single or pci_dma_sync_single is performed.
  47  */
  48 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  49                           enum dma_data_direction direction)
  50 {
  51         BUG_ON(direction == DMA_NONE);
  52
  53         frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
  54
  55         return virt_to_bus(ptr);
  56 }
  57
  58 EXPORT_SYMBOL(dma_map_single);
  59
  60 /*
  61  * Map a set of buffers described by scatterlist in streaming
  62  * mode for DMA.  This is the scather-gather version of the
  63  * above dma_map_single interface.  Here the scatter gather list
  64  * elements are each tagged with the appropriate dma address
  65  * and length.  They are obtained via sg_dma_{address,length}(SG).
  66  *
  67  * NOTE: An implementation may be able to use a smaller number of
  68  *       DMA address/length pairs than there are SG table elements.
  69  *       (for example via virtual mapping capabilities)
  70  *       The routine returns the number of addr/length pairs actually
  71  *       used, at most nents.
  72  *
  73  * Device ownership issues as mentioned above for dma_map_single are
  74  * the same here.
  75  */
  76 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  77                enum dma_data_direction direction)
  78 {
  79         unsigned long dampr2;
  80         void *vaddr;
  81         int i;
  82
  83         BUG_ON(direction == DMA_NONE);
  84
  85         dampr2 = __get_DAMPR(2);
  86
  87         for (i = 0; i < nents; i++) {
  88                 vaddr = kmap_atomic(sg_page(&sg[i]), __KM_CACHE);
  89
  90                 frv_dcache_writeback((unsigned long) vaddr,
  91                                      (unsigned long) vaddr + PAGE_SIZE);
  92
  93         }
  94
  95         kunmap_atomic(vaddr, __KM_CACHE);
  96         if (dampr2) {
  97                 __set_DAMPR(2, dampr2);
  98                 __set_IAMPR(2, dampr2);
  99         }
 100
 101         return nents;
 102 }
 103
 104 EXPORT_SYMBOL(dma_map_sg);
 105
 106 /*
 107  * Map a single page of the indicated size for DMA in streaming mode.
 108  * The 32-bit bus address to use is returned.
 109  *
 110  * Device ownership issues as mentioned above for dma_map_single are
 111  * the same here.
 112  */
 113 dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 114                         size_t size, enum dma_data_direction direction)
 115 {
 116         BUG_ON(direction == DMA_NONE);
 117         flush_dcache_page(page);
 118         return (dma_addr_t) page_to_phys(page) + offset;
 119 }
 120
 121 EXPORT_SYMBOL(dma_map_page);