libavutil/aarch64/timer.h

   1 /*
   2  * Copyright (c) 2015 Janne Grunau <janne-libav@jannau.net>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef AVUTIL_AARCH64_TIMER_H
  22 #define AVUTIL_AARCH64_TIMER_H
  23
  24 #include <stdint.h>
  25 #include "config.h"
  26
  27 #if HAVE_INLINE_ASM
  28
  29 #define AV_READ_TIME read_time
  30
  31 static inline uint64_t read_time(void)
  32 {
  33     uint64_t cycle_counter;
  34     __asm__ volatile(
  35         "isb                   \t\n"
  36         "mrs %0, pmccntr_el0       "
  37         : "=r"(cycle_counter) :: "memory" );
  38
  39     return cycle_counter;
  40 }
  41
  42 #endif /* HAVE_INLINE_ASM */
  43
  44 #endif /* AVUTIL_AARCH64_TIMER_H */