include/asm-mn10300/dma-mapping.h

   1 /* DMA mapping routines for the MN10300 arch
   2  *
   3  * Copyright (C) 2007 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 Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #ifndef _ASM_DMA_MAPPING_H
  12 #define _ASM_DMA_MAPPING_H
  13
  14 #include <linux/mm.h>
  15 #include <linux/scatterlist.h>
  16
  17 #include <asm/cache.h>
  18 #include <asm/io.h>
  19
  20 extern void *dma_alloc_coherent(struct device *dev, size_t size,
  21                                 dma_addr_t *dma_handle, int flag);
  22
  23 extern void dma_free_coherent(struct device *dev, size_t size,
  24                               void *vaddr, dma_addr_t dma_handle);
  25
  26 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent((d), (s), (h), (f))
  27 #define dma_free_noncoherent(d, s, v, h)  dma_free_coherent((d), (s), (v), (h))
  28
  29 /*
  30  * Map a single buffer of the indicated size for DMA in streaming mode.  The
  31  * 32-bit bus address to use is returned.
  32  *
  33  * Once the device is given the dma address, the device owns this memory until
  34  * either pci_unmap_single or pci_dma_sync_single is performed.
  35  */
  36 static inline
  37 dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  38                           enum dma_data_direction direction)
  39 {
  40         BUG_ON(direction == DMA_NONE);
  41         mn10300_dcache_flush_inv();
  42         return virt_to_bus(ptr);
  43 }
  44
  45 /*
  46  * Unmap a single streaming mode DMA translation.  The dma_addr and size must
  47  * match what was provided for in a previous pci_map_single call.  All other
  48  * usages are undefined.
  49  *
  50  * After this call, reads by the cpu to the buffer are guarenteed to see
  51  * whatever the device wrote there.
  52  */
  53 static inline
  54 void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
  55                       enum dma_data_direction direction)
  56 {
  57         BUG_ON(direction == DMA_NONE);
  58 }
  59
  60 /*
  61  * Map a set of buffers described by scatterlist in streaming mode for DMA.
  62  * This is the scather-gather version of the above pci_map_single interface.
  63  * Here the scatter gather list elements are each tagged with the appropriate
  64  * dma address and length.  They are obtained via sg_dma_{address,length}(SG).
  65  *
  66  * NOTE: An implementation may be able to use a smaller number of DMA
  67  *       address/length pairs than there are SG table elements.  (for example
  68  *       via virtual mapping capabilities) The routine returns the number of
  69  *       addr/length pairs actually used, at most nents.
  70  *
  71  * Device ownership issues as mentioned above for pci_map_single are the same
  72  * here.
  73  */
  74 static inline
  75 int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
  76                enum dma_data_direction direction)
  77 {
  78         struct scatterlist *sg;
  79         int i;
  80
  81         BUG_ON(!valid_dma_direction(direction));
  82         WARN_ON(nents == 0 || sglist[0].length == 0);
  83
  84         for_each_sg(sglist, sg, nents, i) {
  85                 BUG_ON(!sg_page(sg));
  86
  87                 sg->dma_address = sg_phys(sg);
  88         }
  89
  90         mn10300_dcache_flush_inv();
  91         return nents;
  92 }
  93
  94 /*
  95  * Unmap a set of streaming mode DMA translations.
  96  * Again, cpu read rules concerning calls here are the same as for
  97  * pci_unmap_single() above.
  98  */
  99 static inline
 100 void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
 101                   enum dma_data_direction direction)
 102 {
 103         BUG_ON(!valid_dma_direction(direction));
 104 }
 105
 106 /*
 107  * pci_{map,unmap}_single_page maps a kernel page to a dma_addr_t. identical
 108  * to pci_map_single, but takes a struct page instead of a virtual address
 109  */
 110 static inline
 111 dma_addr_t dma_map_page(struct device *dev, struct page *page,
 112                         unsigned long offset, size_t size,
 113                         enum dma_data_direction direction)
 114 {
 115         BUG_ON(direction == DMA_NONE);
 116         return page_to_bus(page) + offset;
 117 }
 118
 119 static inline
 120 void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
 121                     enum dma_data_direction direction)
 122 {
 123         BUG_ON(direction == DMA_NONE);
 124 }
 125
 126 /*
 127  * Make physical memory consistent for a single streaming mode DMA translation
 128  * after a transfer.
 129  *
 130  * If you perform a pci_map_single() but wish to interrogate the buffer using
 131  * the cpu, yet do not wish to teardown the PCI dma mapping, you must call this
 132  * function before doing so.  At the next point you give the PCI dma address
 133  * back to the card, the device again owns the buffer.
 134  */
 135 static inline
 136 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 137                              size_t size, enum dma_data_direction direction)
 138 {
 139 }
 140
 141 static inline
 142 void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
 143                                 size_t size, enum dma_data_direction direction)
 144 {
 145         mn10300_dcache_flush_inv();
 146 }
 147
 148 static inline
 149 void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
 150                                    unsigned long offset, size_t size,
 151                                    enum dma_data_direction direction)
 152 {
 153 }
 154
 155 static inline void
 156 dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
 157                                  unsigned long offset, size_t size,
 158                                  enum dma_data_direction direction)
 159 {
 160         mn10300_dcache_flush_inv();
 161 }
 162
 163
 164 /*
 165  * Make physical memory consistent for a set of streaming mode DMA translations
 166  * after a transfer.
 167  *
 168  * The same as pci_dma_sync_single but for a scatter-gather list, same rules
 169  * and usage.
 170  */
 171 static inline
 172 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 173                          int nelems, enum dma_data_direction direction)
 174 {
 175 }
 176
 177 static inline
 178 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 179                             int nelems, enum dma_data_direction direction)
 180 {
 181         mn10300_dcache_flush_inv();
 182 }
 183
 184 static inline
 185 int dma_mapping_error(dma_addr_t dma_addr)
 186 {
 187         return 0;
 188 }
 189
 190 /*
 191  * Return whether the given PCI device DMA address mask can be supported
 192  * properly.  For example, if your device can only drive the low 24-bits during
 193  * PCI bus mastering, then you would pass 0x00ffffff as the mask to this
 194  * function.
 195  */
 196 static inline
 197 int dma_supported(struct device *dev, u64 mask)
 198 {
 199         /*
 200          * we fall back to GFP_DMA when the mask isn't all 1s, so we can't
 201          * guarantee allocations that must be within a tighter range than
 202          * GFP_DMA
 203          */
 204         if (mask < 0x00ffffff)
 205                 return 0;
 206         return 1;
 207 }
 208
 209 static inline
 210 int dma_set_mask(struct device *dev, u64 mask)
 211 {
 212         if (!dev->dma_mask || !dma_supported(dev, mask))
 213                 return -EIO;
 214
 215         *dev->dma_mask = mask;
 216         return 0;
 217 }
 218
 219 static inline
 220 int dma_get_cache_alignment(void)
 221 {
 222         return 1 << L1_CACHE_SHIFT;
 223 }
 224
 225 #define dma_is_consistent(d)    (1)
 226
 227 static inline
 228 void dma_cache_sync(void *vaddr, size_t size,
 229                     enum dma_data_direction direction)
 230 {
 231         mn10300_dcache_flush_inv();
 232 }
 233
 234 #endif