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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.  /** @addtogroup libc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <sys/time.h>
  36. #include <unistd.h>
  37. #include <ipc/ipc.h>
  38. #include <stdio.h>
  39. #include <arch/barrier.h>
  40. #include <unistd.h>
  41. #include <atomic.h>
  42. #include <futex.h>
  43. #include <ipc/services.h>
  44.  
  45. #include <sysinfo.h>
  46. #include <as.h>
  47. #include <ddi.h>
  48.  
  49. /* Pointers to public variables with time */
  50. struct {
  51.     volatile sysarg_t seconds1;
  52.     volatile sysarg_t useconds;
  53.     volatile sysarg_t seconds2;
  54. } *ktime = NULL;
  55.  
  56.  
  57. /** POSIX gettimeofday
  58.  *
  59.  * The time variables are memory mapped(RO) from kernel, which updates
  60.  * them periodically. As it is impossible to read 2 values atomically, we
  61.  * use a trick: First read a seconds, then read microseconds, then
  62.  * read seconds again. If a second elapsed in the meantime, read
  63.  * useconds again. This provides assurance, that at least the
  64.  * sequence of subsequent gettimeofday calls is ordered.
  65.  */
  66. int gettimeofday(struct timeval *tv, struct timezone *tz)
  67. {
  68.     void *mapping;
  69.     sysarg_t s1, s2;
  70.     sysarg_t rights;
  71.     int res;
  72.  
  73.     if (!ktime) {
  74.         mapping = as_get_mappable_page(PAGE_SIZE);
  75.         /* Get the mapping of kernel clock */
  76.         res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
  77.                       mapping, PAGE_SIZE, SERVICE_MEM_REALTIME,
  78.                       NULL,&rights,NULL);
  79.         if (res) {
  80.             printf("Failed to initialize timeofday memarea\n");
  81.             _exit(1);
  82.         }
  83.         if (! (rights & AS_AREA_READ)) {
  84.             printf("Received bad rights on time area: %X\n",
  85.                    rights);
  86.             as_area_destroy(mapping);
  87.             _exit(1);
  88.         }
  89.         ktime = mapping;
  90.     }
  91.     if (tz) {
  92.         tz->tz_minuteswest = 0;
  93.         tz->tz_dsttime = DST_NONE;
  94.     }
  95.  
  96.     s2 = ktime->seconds2;
  97.     read_barrier();
  98.     tv->tv_usec = ktime->useconds;
  99.     read_barrier();
  100.     s1 = ktime->seconds1;
  101.     if (s1 != s2) {
  102.         tv->tv_usec = 0;
  103.         tv->tv_sec = s1 > s2 ? s1 : s2;
  104.     } else
  105.         tv->tv_sec = s1;
  106.  
  107.     return 0;
  108. }
  109.  
  110. /** Wait unconditionally for specified microseconds */
  111. void usleep(unsigned long usec)
  112. {
  113.     atomic_t futex = FUTEX_INITIALIZER;
  114.  
  115.     futex_initialize(&futex,0);
  116.     futex_down_timeout(&futex, usec, 0);
  117. }
  118.  
  119.  
  120.  /** @}
  121.  */
  122.  
  123.  
  124.