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  1. /*
  2.  * Copyright (C) 2006 Ondrej Palkovsky
  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.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - 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.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <sys/time.h>
  30. #include <unistd.h>
  31. #include <ipc/ipc.h>
  32. #include <stdio.h>
  33. #include <arch/barrier.h>
  34. #include <unistd.h>
  35. #include <atomic.h>
  36. #include <futex.h>
  37.  
  38. #include <sysinfo.h>
  39. #include <as.h>
  40. #include <ddi.h>
  41.  
  42. /* Pointers to public variables with time */
  43. struct {
  44.     volatile sysarg_t seconds1;
  45.     volatile sysarg_t useconds;
  46.     volatile sysarg_t seconds2;
  47. } *ktime = NULL;
  48.  
  49.  
  50. /** POSIX gettimeofday
  51.  *
  52.  * The time variables are memory mapped(RO) from kernel, which updates
  53.  * them periodically. As it is impossible to read 2 values atomically, we
  54.  * use a trick: First read a seconds, then read microseconds, then
  55.  * read seconds again. If a second elapsed in the meantime, read
  56.  * useconds again. This provides assurance, that at least the
  57.  * sequence of subsequent gettimeofday calls is ordered.
  58.  */
  59. int gettimeofday(struct timeval *tv, struct timezone *tz)
  60. {
  61.     void *mapping;
  62.     sysarg_t s1, s2;
  63.     sysarg_t rights;
  64.     int res;
  65.  
  66.     if (!ktime) {
  67.         mapping = as_get_mappable_page(PAGE_SIZE);
  68.         /* Get the mapping of kernel clock */
  69.         res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
  70.                       mapping, PAGE_SIZE, 0,
  71.                       NULL,&rights,NULL);
  72.         if (res) {
  73.             printf("Failed to initialize timeofday memarea\n");
  74.             _exit(1);
  75.         }
  76.         if (rights != (AS_AREA_READ | AS_AREA_CACHEABLE)) {
  77.             printf("Received bad rights on time area: %X\n",
  78.                    rights);
  79.             as_area_destroy(mapping);
  80.             _exit(1);
  81.         }
  82.         ktime = mapping;
  83.     }
  84.     if (tz) {
  85.         tz->tz_minuteswest = 0;
  86.         tz->tz_dsttime = DST_NONE;
  87.     }
  88.  
  89.     s2 = ktime->seconds2;
  90.     read_barrier();
  91.     tv->tv_usec = ktime->useconds;
  92.     read_barrier();
  93.     s1 = ktime->seconds1;
  94.     if (s1 != s2) {
  95.         tv->tv_usec = 0;
  96.         tv->tv_sec = s1 > s2 ? s1 : s2;
  97.     } else
  98.         tv->tv_sec = s1;
  99.  
  100.     return 0;
  101. }
  102.  
  103. /** Wait unconditionally for specified microseconds */
  104. void usleep(unsigned long usec)
  105. {
  106.     atomic_t futex = FUTEX_INITIALIZER;
  107.  
  108.     futex_initialize(&futex,0);
  109.     futex_down_timeout(&futex, usec, 0);
  110. }
  111.