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

   1 /*
   2  * Copyright (c) 2015 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_IOMAPPING_H_
  28 #define _LINUX_IOMAPPING_H_
  29
  30 #include <linux/types.h>
  31 #include <linux/io.h>
  32
  33 struct io_mapping {
  34         resource_size_t base;
  35         unsigned long size;
  36         unsigned long prot;
  37         void *vaddr;
  38 };
  39
  40 static inline struct io_mapping *
  41 io_mapping_create_wc(resource_size_t base, unsigned long size)
  42 {
  43         struct io_mapping *map;
  44
  45         map = kmalloc(sizeof(struct io_mapping), M_DRM, M_WAITOK);
  46         map->base = base;
  47         map->size = size;
  48         map->prot = VM_MEMATTR_WRITE_COMBINING;
  49
  50         map->vaddr = pmap_mapdev_attr(base, size,
  51                                         VM_MEMATTR_WRITE_COMBINING);
  52         if (map->vaddr == NULL)
  53                 return NULL;
  54
  55         return map;
  56 }
  57
  58 static inline void io_mapping_free(struct io_mapping *mapping)
  59 {
  60         /* Default memory attribute is write-back */
  61         pmap_mapdev_attr(mapping->base, mapping->size, VM_MEMATTR_WRITE_BACK);
  62         kfree(mapping);
  63 }
  64
  65 static inline void *
  66 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
  67 {
  68         return (void *)PHYS_TO_DMAP(mapping->base + offset);
  69 }
  70
  71 static inline void *
  72 io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
  73 {
  74         return io_mapping_map_atomic_wc(mapping, offset);
  75 }
  76
  77 static inline void io_mapping_unmap_atomic(void *vaddr)
  78 {
  79 }
  80
  81 #endif  /* _LINUX_IOMAPPING_H_ */