dc01c9fae1
The code was only halfarsed converted to the new VSDO update mechanism and still uses the inaccurate base value which lacks the fractional part of xtime_nsec. Fix it up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
/*
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* Copyright 2012 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#define VDSO_BUILD /* avoid some shift warnings for -m32 in <asm/page.h> */
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#include <linux/time.h>
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#include <asm/timex.h>
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#include <asm/vdso.h>
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#if CHIP_HAS_SPLIT_CYCLE()
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static inline cycles_t get_cycles_inline(void)
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{
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unsigned int high = __insn_mfspr(SPR_CYCLE_HIGH);
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unsigned int low = __insn_mfspr(SPR_CYCLE_LOW);
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unsigned int high2 = __insn_mfspr(SPR_CYCLE_HIGH);
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while (unlikely(high != high2)) {
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low = __insn_mfspr(SPR_CYCLE_LOW);
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high = high2;
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high2 = __insn_mfspr(SPR_CYCLE_HIGH);
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}
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return (((cycles_t)high) << 32) | low;
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}
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#define get_cycles get_cycles_inline
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#endif
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/*
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* Find out the vDSO data page address in the process address space.
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*/
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inline unsigned long get_datapage(void)
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{
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unsigned long ret;
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/* vdso data page located in the 2nd vDSO page. */
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asm volatile ("lnk %0" : "=r"(ret));
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ret &= ~(PAGE_SIZE - 1);
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ret += PAGE_SIZE;
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return ret;
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}
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int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
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{
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cycles_t cycles;
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unsigned long count, sec, ns;
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volatile struct vdso_data *vdso_data;
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vdso_data = (struct vdso_data *)get_datapage();
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/* The use of the timezone is obsolete, normally tz is NULL. */
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if (unlikely(tz != NULL)) {
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while (1) {
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/* Spin until the update finish. */
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count = vdso_data->tz_update_count;
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if (count & 1)
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continue;
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tz->tz_minuteswest = vdso_data->tz_minuteswest;
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tz->tz_dsttime = vdso_data->tz_dsttime;
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/* Check whether updated, read again if so. */
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if (count == vdso_data->tz_update_count)
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break;
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}
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}
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if (unlikely(tv == NULL))
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return 0;
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while (1) {
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/* Spin until the update finish. */
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count = vdso_data->tb_update_count;
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if (count & 1)
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continue;
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sec = vdso_data->xtime_clock_sec;
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cycles = get_cycles() - vdso_data->xtime_tod_stamp;
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ns = (cycles * vdso_data->mult) + vdso_data->xtime_clock_nsec;
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ns >>= vdso_data->shift;
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if (ns >= NSEC_PER_SEC) {
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ns -= NSEC_PER_SEC;
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sec += 1;
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}
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/* Check whether updated, read again if so. */
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if (count == vdso_data->tb_update_count)
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break;
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}
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tv->tv_sec = sec;
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tv->tv_usec = ns / 1000;
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return 0;
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}
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int gettimeofday(struct timeval *tv, struct timezone *tz)
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__attribute__((weak, alias("__vdso_gettimeofday")));
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