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 <asm/io.h>
  19
  20 void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, int gfp)
  21 {
  22         void *ret;
  23
  24         ret = consistent_alloc(gfp, size, dma_handle);
  25         if (ret)
  26                 memset(ret, 0, size);
  27
  28         return ret;
  29 }
  30
  31 void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
  32 {
  33         consistent_free(vaddr);
  34 }
  35
  36 /*
  37  * Map a single buffer of the indicated size for DMA in streaming mode.
  38  * The 32-bit bus address to use is returned.
  39  *
  40  * Once the device is given the dma address, the device owns this memory
  41  * until either pci_unmap_single or pci_dma_sync_single is performed.
  42  */
  43 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  44                           enum dma_data_direction direction)
  45 {
  46         if (direction == DMA_NONE)
  47                 BUG();
  48
  49         frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
  50
  51         return virt_to_bus(ptr);
  52 }
  53
  54 /*
  55  * Map a set of buffers described by scatterlist in streaming
  56  * mode for DMA.  This is the scather-gather version of the
  57  * above pci_map_single interface.  Here the scatter gather list
  58  * elements are each tagged with the appropriate dma address
  59  * and length.  They are obtained via sg_dma_{address,length}(SG).
  60  *
  61  * NOTE: An implementation may be able to use a smaller number of
  62  *       DMA address/length pairs than there are SG table elements.
  63  *       (for example via virtual mapping capabilities)
  64  *       The routine returns the number of addr/length pairs actually
  65  *       used, at most nents.
  66  *
  67  * Device ownership issues as mentioned above for pci_map_single are
  68  * the same here.
  69  */
  70 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  71                enum dma_data_direction direction)
  72 {
  73         unsigned long dampr2;
  74         void *vaddr;
  75         int i;
  76
  77         if (direction == DMA_NONE)
  78                 BUG();
  79
  80         dampr2 = __get_DAMPR(2);
  81
  82         for (i = 0; i < nents; i++) {
  83                 vaddr = kmap_atomic(sg[i].page, __KM_CACHE);
  84
  85                 frv_dcache_writeback((unsigned long) vaddr,
  86                                      (unsigned long) vaddr + PAGE_SIZE);
  87
  88         }
  89
  90         kunmap_atomic(vaddr, __KM_CACHE);
  91         if (dampr2) {
  92                 __set_DAMPR(2, dampr2);
  93                 __set_IAMPR(2, dampr2);
  94         }
  95
  96         return nents;
  97 }
  98
  99 dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 100                         size_t size, enum dma_data_direction direction)
 101 {
 102         BUG_ON(direction == DMA_NONE);
 103         flush_dcache_page(page);
 104         return (dma_addr_t) page_to_phys(page) + offset;
 105 }