sys/dev/drm/include/linux/dma-mapping.h

   1 /*
   2  * Copyright (c) 2015-2016 François Tigeot
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef _LINUX_DMA_MAPPING_H_
  28 #define _LINUX_DMA_MAPPING_H_
  29
  30 #include <linux/string.h>
  31 #include <linux/device.h>
  32 #include <linux/err.h>
  33 #include <linux/dma-direction.h>
  34 #include <linux/scatterlist.h>
  35
  36 static inline dma_addr_t
  37 dma_map_page(struct device *dev, struct vm_page *page,
  38     unsigned long offset, size_t size, enum dma_data_direction direction)
  39 {
  40         return VM_PAGE_TO_PHYS(page) + offset;
  41 }
  42
  43 static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,
  44                                   size_t size, enum dma_data_direction dir)
  45 {
  46 }
  47
  48 static inline int
  49 dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  50 {
  51         return 0;
  52 }
  53
  54 static inline int
  55 dma_map_sg(struct device *dev, struct scatterlist *sg,
  56            int nents, enum dma_data_direction dir)
  57 {
  58         struct scatterlist *s;
  59         int i;
  60
  61         for_each_sg(sg, s, nents, i)
  62                 s->dma_address = sg_phys(s);
  63
  64         return nents;
  65 }
  66
  67 static inline void
  68 dma_unmap_sg(struct device *dev, struct scatterlist *sg,
  69              int nents, enum dma_data_direction dir)
  70 {
  71 }
  72
  73 #endif  /* _LINUX_DMA-MAPPING_H_ */