src/mesa/drivers/dri/i965/libdrm_macros.h

   1 /*
   2  * Copyright © 2014 NVIDIA Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 #ifndef LIBDRM_LIBDRM_H
  24 #define LIBDRM_LIBDRM_H
  25
  26 /**
  27  * Static (compile-time) assertion.
  28  * Basically, use COND to dimension an array.  If COND is false/zero the
  29  * array size will be -1 and we'll get a compilation error.
  30  */
  31 #define STATIC_ASSERT(COND) \
  32    do { \
  33       (void) sizeof(char [1 - 2*!(COND)]); \
  34    } while (0)
  35
  36
  37 #include <sys/mman.h>
  38
  39 #if defined(ANDROID) && !defined(__LP64__)
  40 #include <errno.h> /* for EINVAL */
  41
  42 extern void *__mmap2(void *, size_t, int, int, int, size_t);
  43
  44 static inline void *drm_mmap(void *addr, size_t length, int prot, int flags,
  45                              int fd, loff_t offset)
  46 {
  47    /* offset must be aligned to 4096 (not necessarily the page size) */
  48    if (offset & 4095) {
  49       errno = EINVAL;
  50       return MAP_FAILED;
  51    }
  52
  53    return __mmap2(addr, length, prot, flags, fd, (size_t) (offset >> 12));
  54 }
  55
  56 #  define drm_munmap(addr, length) \
  57               munmap(addr, length)
  58
  59
  60 #else
  61
  62 /* assume large file support exists */
  63 #  define drm_mmap(addr, length, prot, flags, fd, offset) \
  64               mmap(addr, length, prot, flags, fd, offset)
  65
  66
  67 static inline int drm_munmap(void *addr, size_t length)
  68 {
  69    /* Copied from configure code generated by AC_SYS_LARGEFILE */
  70 #define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + \
  71                      (((off_t) 1 << 31) << 31))
  72    STATIC_ASSERT(LARGE_OFF_T % 2147483629 == 721 &&
  73                  LARGE_OFF_T % 2147483647 == 1);
  74 #undef LARGE_OFF_T
  75
  76    return munmap(addr, length);
  77 }
  78 #endif
  79
  80 #endif