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      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 #if defined(HAVE_VISIBILITY)
     27 #  define drm_private __attribute__((visibility("hidden")))
     28 #else
     29 #  define drm_private
     30 #endif
     31 
     32 
     33 /**
     34  * Static (compile-time) assertion.
     35  * Basically, use COND to dimension an array.  If COND is false/zero the
     36  * array size will be -1 and we'll get a compilation error.
     37  */
     38 #define STATIC_ASSERT(COND) \
     39    do { \
     40       (void) sizeof(char [1 - 2*!(COND)]); \
     41    } while (0)
     42 
     43 
     44 #include <sys/mman.h>
     45 
     46 #if defined(ANDROID) && !defined(__LP64__)
     47 #include <errno.h> /* for EINVAL */
     48 
     49 static inline void *drm_mmap(void *addr, size_t length, int prot, int flags,
     50                              int fd, loff_t offset)
     51 {
     52    /* offset must be aligned to 4096 (not necessarily the page size) */
     53    if (offset & 4095) {
     54       errno = EINVAL;
     55       return MAP_FAILED;
     56    }
     57 
     58    return mmap64(addr, length, prot, flags, fd, offset);
     59 }
     60 
     61 #  define drm_munmap(addr, length) \
     62               munmap(addr, length)
     63 
     64 
     65 #else
     66 
     67 /* assume large file support exists */
     68 #  define drm_mmap(addr, length, prot, flags, fd, offset) \
     69               mmap(addr, length, prot, flags, fd, offset)
     70 
     71 
     72 static inline int drm_munmap(void *addr, size_t length)
     73 {
     74    /* Copied from configure code generated by AC_SYS_LARGEFILE */
     75 #define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + \
     76                      (((off_t) 1 << 31) << 31))
     77    STATIC_ASSERT(LARGE_OFF_T % 2147483629 == 721 &&
     78                  LARGE_OFF_T % 2147483647 == 1);
     79 #undef LARGE_OFF_T
     80 
     81    return munmap(addr, length);
     82 }
     83 #endif
     84 
     85 #endif
     86