0,0 → 1,96 |
/* |
* Copyright (C) 2006 Ondrej Palkovsky |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
#include <time.h> |
#include <unistd.h> |
#include <ipc/ipc.h> |
#include <stdio.h> |
#include <arch/barrier.h> |
|
#include <sysinfo.h> |
#include <as.h> |
#include <ddi.h> |
|
/* Pointers to public variables with time */ |
struct { |
volatile sysarg_t seconds; |
volatile sysarg_t useconds; |
volatile sysarg_t useconds2; |
} *ktime = NULL; |
|
|
/** POSIX gettimeofday |
* |
* The time variables are memory mapped(RO) from kernel, which updates |
* them periodically. As it is impossible to read 2 values atomically, we |
* use a trick: First read a seconds, then read microseconds, then |
* read seconds again. If a second elapsed in the meantime, read |
* useconds again. This provides assurance, that at least the |
* sequence of subsequent gettimeofday calls is ordered. |
*/ |
#define TMAREA (100*1024*1024) |
int gettimeofday(struct timeval *tv, struct timezone *tz) |
{ |
void *mapping; |
sysarg_t seconds,useconds; |
sysarg_t t1; |
int res; |
|
if (!ktime) { |
/* TODO: specify better, where to map the area */ |
/* Get the mapping of kernel clock */ |
res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV, |
TMAREA, |
PAGE_SIZE, |
AS_AREA_READ | AS_AREA_CACHEABLE, |
&t1,&t1,&t1); |
if (res) { |
printf("Failed to initialize timeofday memarea\n"); |
_exit(1); |
} |
ktime = (void *) (TMAREA); |
} |
tz->tz_minuteswest = 0; |
tz->tz_dsttime = DST_NONE; |
retry: |
seconds = ktime->seconds; |
read_barrier(); |
tv->tv_usec = ktime->useconds; |
read_barrier(); |
tv->tv_sec = ktime->seconds; |
if (tv->tv_usec == 0 && seconds == tv->tv_sec && |
ktime->useconds2 != 0) { |
read_barrier(); |
goto retry; |
} |
|
if (seconds != tv->tv_sec) |
tv->tv_usec = ktime->useconds; |
|
return 0; |
} |