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         if (direction == DMA_NONE)
  52                 BUG();
  53
  54         frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
  55
  56         return virt_to_bus(ptr);
  57 }
  58
  59 EXPORT_SYMBOL(dma_map_single);
  60
  61 /*
  62  * Map a set of buffers described by scatterlist in streaming
  63  * mode for DMA.  This is the scather-gather version of the
  64  * above dma_map_single interface.  Here the scatter gather list
  65  * elements are each tagged with the appropriate dma address
  66  * and length.  They are obtained via sg_dma_{address,length}(SG).
  67  *
  68  * NOTE: An implementation may be able to use a smaller number of
  69  *       DMA address/length pairs than there are SG table elements.
  70  *       (for example via virtual mapping capabilities)
  71  *       The routine returns the number of addr/length pairs actually
  72  *       used, at most nents.
  73  *
  74  * Device ownership issues as mentioned above for dma_map_single are
  75  * the same here.
  76  */
  77 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  78                enum dma_data_direction direction)
  79 {
  80         unsigned long dampr2;
  81         void *vaddr;
  82         int i;
  83
  84         if (direction == DMA_NONE)
  85                 BUG();
  86
  87         dampr2 = __get_DAMPR(2);
  88
  89         for (i = 0; i < nents; i++) {
  90                 vaddr = kmap_atomic(sg_page(&sg[i]), __KM_CACHE);
  91
  92                 frv_dcache_writeback((unsigned long) vaddr,
  93                                      (unsigned long) vaddr + PAGE_SIZE);
  94
  95         }
  96
  97         kunmap_atomic(vaddr, __KM_CACHE);
  98         if (dampr2) {
  99                 __set_DAMPR(2, dampr2);
 100                 __set_IAMPR(2, dampr2);
 101         }
 102
 103         return nents;
 104 }
 105
 106 EXPORT_SYMBOL(dma_map_sg);
 107
 108 /*
 109  * Map a single page of the indicated size for DMA in streaming mode.
 110  * The 32-bit bus address to use is returned.
 111  *
 112  * Device ownership issues as mentioned above for dma_map_single are
 113  * the same here.
 114  */
 115 dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 116                         size_t size, enum dma_data_direction direction)
 117 {
 118         BUG_ON(direction == DMA_NONE);
 119         flush_dcache_page(page);
 120         return (dma_addr_t) page_to_phys(page) + offset;
 121 }
 122
 123 EXPORT_SYMBOL(dma_map_page);