sys/dev/drm/linux_dma.c

   1 /*
   2  * Copyright (c) 2016 Sascha Wildner <saw@online.de>
   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 #include <linux/dma-mapping.h>
  28
  29 #include <vm/vm_extern.h>
  30
  31 void *
  32 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
  33     gfp_t flag)
  34 {
  35         vm_paddr_t high;
  36         size_t align;
  37         void *mem;
  38
  39 #if 0 /* XXX swildner */
  40         if (dev->dma_mask)
  41                 high = *dev->dma_mask;
  42         else
  43 #endif
  44                 high = BUS_SPACE_MAXADDR_32BIT;
  45         align = PAGE_SIZE << get_order(size);
  46         mem = (void *)kmem_alloc_contig(size, 0, high, align);
  47         if (mem)
  48                 *dma_handle = vtophys(mem);
  49         else
  50                 *dma_handle = 0;
  51         return (mem);
  52 }
  53
  54 void
  55 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
  56     dma_addr_t dma_handle)
  57 {
  58
  59         kmem_free(&kernel_map, (vm_offset_t)cpu_addr, size);
  60 }