Rev 1439 | Go to most recent revision | Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
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| 1435 | palkovsky | 1 | /* |
| 2 | * Copyright (C) 2006 Ondrej Palkovsky |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #include <time.h> |
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| 30 | #include <unistd.h> |
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| 31 | #include <ipc/ipc.h> |
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| 32 | #include <stdio.h> |
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| 33 | #include <arch/barrier.h> |
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| 34 | |||
| 35 | #include <sysinfo.h> |
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| 36 | #include <as.h> |
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| 37 | #include <ddi.h> |
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| 38 | |||
| 39 | /* Pointers to public variables with time */ |
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| 40 | struct { |
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| 41 | volatile sysarg_t seconds; |
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| 42 | volatile sysarg_t useconds; |
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| 43 | volatile sysarg_t useconds2; |
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| 44 | } *ktime = NULL; |
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| 45 | |||
| 46 | |||
| 47 | /** POSIX gettimeofday |
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| 48 | * |
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| 49 | * The time variables are memory mapped(RO) from kernel, which updates |
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| 50 | * them periodically. As it is impossible to read 2 values atomically, we |
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| 51 | * use a trick: First read a seconds, then read microseconds, then |
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| 52 | * read seconds again. If a second elapsed in the meantime, read |
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| 53 | * useconds again. This provides assurance, that at least the |
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| 54 | * sequence of subsequent gettimeofday calls is ordered. |
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| 55 | */ |
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| 56 | #define TMAREA (100*1024*1024) |
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| 57 | int gettimeofday(struct timeval *tv, struct timezone *tz) |
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| 58 | { |
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| 59 | void *mapping; |
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| 60 | sysarg_t seconds,useconds; |
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| 61 | sysarg_t t1; |
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| 62 | int res; |
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| 63 | |||
| 64 | if (!ktime) { |
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| 65 | /* TODO: specify better, where to map the area */ |
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| 66 | /* Get the mapping of kernel clock */ |
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| 67 | res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV, |
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| 68 | TMAREA, |
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| 69 | PAGE_SIZE, |
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| 70 | AS_AREA_READ | AS_AREA_CACHEABLE, |
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| 71 | &t1,&t1,&t1); |
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| 72 | if (res) { |
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| 73 | printf("Failed to initialize timeofday memarea\n"); |
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| 74 | _exit(1); |
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| 75 | } |
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| 76 | ktime = (void *) (TMAREA); |
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| 77 | } |
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| 78 | tz->tz_minuteswest = 0; |
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| 79 | tz->tz_dsttime = DST_NONE; |
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| 80 | retry: |
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| 81 | seconds = ktime->seconds; |
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| 82 | read_barrier(); |
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| 83 | tv->tv_usec = ktime->useconds; |
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| 84 | read_barrier(); |
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| 85 | tv->tv_sec = ktime->seconds; |
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| 86 | if (tv->tv_usec == 0 && seconds == tv->tv_sec && |
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| 87 | ktime->useconds2 != 0) { |
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| 88 | read_barrier(); |
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| 89 | goto retry; |
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| 90 | } |
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| 91 | |||
| 92 | if (seconds != tv->tv_sec) |
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| 93 | tv->tv_usec = ktime->useconds; |
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| 94 | |||
| 95 | return 0; |
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| 96 | } |