diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2014-06-22 12:06:40 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2014-06-23 11:22:35 +0200 |
commit | 5cee964597260237dd2cabb3ec22bba0da24b25d (patch) | |
tree | f548efb4181a4cffb026adf43178e65330533e87 /kernel/time.c | |
parent | 58394271c610e9c65dd0165a1c1f6dec75dc5f3e (diff) | |
download | linux-5cee964597260237dd2cabb3ec22bba0da24b25d.tar.bz2 |
time/timers: Move all time(r) related files into kernel/time
Except for Kconfig.HZ. That needs a separate treatment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time.c')
-rw-r--r-- | kernel/time.c | 714 |
1 files changed, 0 insertions, 714 deletions
diff --git a/kernel/time.c b/kernel/time.c deleted file mode 100644 index 7c7964c33ae7..000000000000 --- a/kernel/time.c +++ /dev/null @@ -1,714 +0,0 @@ -/* - * linux/kernel/time.c - * - * Copyright (C) 1991, 1992 Linus Torvalds - * - * This file contains the interface functions for the various - * time related system calls: time, stime, gettimeofday, settimeofday, - * adjtime - */ -/* - * Modification history kernel/time.c - * - * 1993-09-02 Philip Gladstone - * Created file with time related functions from sched/core.c and adjtimex() - * 1993-10-08 Torsten Duwe - * adjtime interface update and CMOS clock write code - * 1995-08-13 Torsten Duwe - * kernel PLL updated to 1994-12-13 specs (rfc-1589) - * 1999-01-16 Ulrich Windl - * Introduced error checking for many cases in adjtimex(). - * Updated NTP code according to technical memorandum Jan '96 - * "A Kernel Model for Precision Timekeeping" by Dave Mills - * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10) - * (Even though the technical memorandum forbids it) - * 2004-07-14 Christoph Lameter - * Added getnstimeofday to allow the posix timer functions to return - * with nanosecond accuracy - */ - -#include <linux/export.h> -#include <linux/timex.h> -#include <linux/capability.h> -#include <linux/timekeeper_internal.h> -#include <linux/errno.h> -#include <linux/syscalls.h> -#include <linux/security.h> -#include <linux/fs.h> -#include <linux/math64.h> -#include <linux/ptrace.h> - -#include <asm/uaccess.h> -#include <asm/unistd.h> - -#include "timeconst.h" - -/* - * The timezone where the local system is located. Used as a default by some - * programs who obtain this value by using gettimeofday. - */ -struct timezone sys_tz; - -EXPORT_SYMBOL(sys_tz); - -#ifdef __ARCH_WANT_SYS_TIME - -/* - * sys_time() can be implemented in user-level using - * sys_gettimeofday(). Is this for backwards compatibility? If so, - * why not move it into the appropriate arch directory (for those - * architectures that need it). - */ -SYSCALL_DEFINE1(time, time_t __user *, tloc) -{ - time_t i = get_seconds(); - - if (tloc) { - if (put_user(i,tloc)) - return -EFAULT; - } - force_successful_syscall_return(); - return i; -} - -/* - * sys_stime() can be implemented in user-level using - * sys_settimeofday(). Is this for backwards compatibility? If so, - * why not move it into the appropriate arch directory (for those - * architectures that need it). - */ - -SYSCALL_DEFINE1(stime, time_t __user *, tptr) -{ - struct timespec tv; - int err; - - if (get_user(tv.tv_sec, tptr)) - return -EFAULT; - - tv.tv_nsec = 0; - - err = security_settime(&tv, NULL); - if (err) - return err; - - do_settimeofday(&tv); - return 0; -} - -#endif /* __ARCH_WANT_SYS_TIME */ - -SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, - struct timezone __user *, tz) -{ - if (likely(tv != NULL)) { - struct timeval ktv; - do_gettimeofday(&ktv); - if (copy_to_user(tv, &ktv, sizeof(ktv))) - return -EFAULT; - } - if (unlikely(tz != NULL)) { - if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) - return -EFAULT; - } - return 0; -} - -/* - * Indicates if there is an offset between the system clock and the hardware - * clock/persistent clock/rtc. - */ -int persistent_clock_is_local; - -/* - * Adjust the time obtained from the CMOS to be UTC time instead of - * local time. - * - * This is ugly, but preferable to the alternatives. Otherwise we - * would either need to write a program to do it in /etc/rc (and risk - * confusion if the program gets run more than once; it would also be - * hard to make the program warp the clock precisely n hours) or - * compile in the timezone information into the kernel. Bad, bad.... - * - * - TYT, 1992-01-01 - * - * The best thing to do is to keep the CMOS clock in universal time (UTC) - * as real UNIX machines always do it. This avoids all headaches about - * daylight saving times and warping kernel clocks. - */ -static inline void warp_clock(void) -{ - if (sys_tz.tz_minuteswest != 0) { - struct timespec adjust; - - persistent_clock_is_local = 1; - adjust.tv_sec = sys_tz.tz_minuteswest * 60; - adjust.tv_nsec = 0; - timekeeping_inject_offset(&adjust); - } -} - -/* - * In case for some reason the CMOS clock has not already been running - * in UTC, but in some local time: The first time we set the timezone, - * we will warp the clock so that it is ticking UTC time instead of - * local time. Presumably, if someone is setting the timezone then we - * are running in an environment where the programs understand about - * timezones. This should be done at boot time in the /etc/rc script, - * as soon as possible, so that the clock can be set right. Otherwise, - * various programs will get confused when the clock gets warped. - */ - -int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz) -{ - static int firsttime = 1; - int error = 0; - - if (tv && !timespec_valid(tv)) - return -EINVAL; - - error = security_settime(tv, tz); - if (error) - return error; - - if (tz) { - sys_tz = *tz; - update_vsyscall_tz(); - if (firsttime) { - firsttime = 0; - if (!tv) - warp_clock(); - } - } - if (tv) - return do_settimeofday(tv); - return 0; -} - -SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, - struct timezone __user *, tz) -{ - struct timeval user_tv; - struct timespec new_ts; - struct timezone new_tz; - - if (tv) { - if (copy_from_user(&user_tv, tv, sizeof(*tv))) - return -EFAULT; - new_ts.tv_sec = user_tv.tv_sec; - new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; - } - if (tz) { - if (copy_from_user(&new_tz, tz, sizeof(*tz))) - return -EFAULT; - } - - return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); -} - -SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) -{ - struct timex txc; /* Local copy of parameter */ - int ret; - - /* Copy the user data space into the kernel copy - * structure. But bear in mind that the structures - * may change - */ - if(copy_from_user(&txc, txc_p, sizeof(struct timex))) - return -EFAULT; - ret = do_adjtimex(&txc); - return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; -} - -/** - * current_fs_time - Return FS time - * @sb: Superblock. - * - * Return the current time truncated to the time granularity supported by - * the fs. - */ -struct timespec current_fs_time(struct super_block *sb) -{ - struct timespec now = current_kernel_time(); - return timespec_trunc(now, sb->s_time_gran); -} -EXPORT_SYMBOL(current_fs_time); - -/* - * Convert jiffies to milliseconds and back. - * - * Avoid unnecessary multiplications/divisions in the - * two most common HZ cases: - */ -unsigned int jiffies_to_msecs(const unsigned long j) -{ -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) - return (MSEC_PER_SEC / HZ) * j; -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) - return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); -#else -# if BITS_PER_LONG == 32 - return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32; -# else - return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN; -# endif -#endif -} -EXPORT_SYMBOL(jiffies_to_msecs); - -unsigned int jiffies_to_usecs(const unsigned long j) -{ -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) - return (USEC_PER_SEC / HZ) * j; -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC); -#else -# if BITS_PER_LONG == 32 - return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; -# else - return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; -# endif -#endif -} -EXPORT_SYMBOL(jiffies_to_usecs); - -/** - * timespec_trunc - Truncate timespec to a granularity - * @t: Timespec - * @gran: Granularity in ns. - * - * Truncate a timespec to a granularity. gran must be smaller than a second. - * Always rounds down. - * - * This function should be only used for timestamps returned by - * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because - * it doesn't handle the better resolution of the latter. - */ -struct timespec timespec_trunc(struct timespec t, unsigned gran) -{ - /* - * Division is pretty slow so avoid it for common cases. - * Currently current_kernel_time() never returns better than - * jiffies resolution. Exploit that. - */ - if (gran <= jiffies_to_usecs(1) * 1000) { - /* nothing */ - } else if (gran == 1000000000) { - t.tv_nsec = 0; - } else { - t.tv_nsec -= t.tv_nsec % gran; - } - return t; -} -EXPORT_SYMBOL(timespec_trunc); - -/* Converts Gregorian date to seconds since 1970-01-01 00:00:00. - * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 - * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. - * - * [For the Julian calendar (which was used in Russia before 1917, - * Britain & colonies before 1752, anywhere else before 1582, - * and is still in use by some communities) leave out the - * -year/100+year/400 terms, and add 10.] - * - * This algorithm was first published by Gauss (I think). - * - * WARNING: this function will overflow on 2106-02-07 06:28:16 on - * machines where long is 32-bit! (However, as time_t is signed, we - * will already get problems at other places on 2038-01-19 03:14:08) - */ -unsigned long -mktime(const unsigned int year0, const unsigned int mon0, - const unsigned int day, const unsigned int hour, - const unsigned int min, const unsigned int sec) -{ - unsigned int mon = mon0, year = year0; - - /* 1..12 -> 11,12,1..10 */ - if (0 >= (int) (mon -= 2)) { - mon += 12; /* Puts Feb last since it has leap day */ - year -= 1; - } - - return ((((unsigned long) - (year/4 - year/100 + year/400 + 367*mon/12 + day) + - year*365 - 719499 - )*24 + hour /* now have hours */ - )*60 + min /* now have minutes */ - )*60 + sec; /* finally seconds */ -} - -EXPORT_SYMBOL(mktime); - -/** - * set_normalized_timespec - set timespec sec and nsec parts and normalize - * - * @ts: pointer to timespec variable to be set - * @sec: seconds to set - * @nsec: nanoseconds to set - * - * Set seconds and nanoseconds field of a timespec variable and - * normalize to the timespec storage format - * - * Note: The tv_nsec part is always in the range of - * 0 <= tv_nsec < NSEC_PER_SEC - * For negative values only the tv_sec field is negative ! - */ -void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) -{ - while (nsec >= NSEC_PER_SEC) { - /* - * The following asm() prevents the compiler from - * optimising this loop into a modulo operation. See - * also __iter_div_u64_rem() in include/linux/time.h - */ - asm("" : "+rm"(nsec)); - nsec -= NSEC_PER_SEC; - ++sec; - } - while (nsec < 0) { - asm("" : "+rm"(nsec)); - nsec += NSEC_PER_SEC; - --sec; - } - ts->tv_sec = sec; - ts->tv_nsec = nsec; -} -EXPORT_SYMBOL(set_normalized_timespec); - -/** - * ns_to_timespec - Convert nanoseconds to timespec - * @nsec: the nanoseconds value to be converted - * - * Returns the timespec representation of the nsec parameter. - */ -struct timespec ns_to_timespec(const s64 nsec) -{ - struct timespec ts; - s32 rem; - - if (!nsec) - return (struct timespec) {0, 0}; - - ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); - if (unlikely(rem < 0)) { - ts.tv_sec--; - rem += NSEC_PER_SEC; - } - ts.tv_nsec = rem; - - return ts; -} -EXPORT_SYMBOL(ns_to_timespec); - -/** - * ns_to_timeval - Convert nanoseconds to timeval - * @nsec: the nanoseconds value to be converted - * - * Returns the timeval representation of the nsec parameter. - */ -struct timeval ns_to_timeval(const s64 nsec) -{ - struct timespec ts = ns_to_timespec(nsec); - struct timeval tv; - - tv.tv_sec = ts.tv_sec; - tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; - - return tv; -} -EXPORT_SYMBOL(ns_to_timeval); - -/* - * When we convert to jiffies then we interpret incoming values - * the following way: - * - * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) - * - * - 'too large' values [that would result in larger than - * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. - * - * - all other values are converted to jiffies by either multiplying - * the input value by a factor or dividing it with a factor - * - * We must also be careful about 32-bit overflows. - */ -unsigned long msecs_to_jiffies(const unsigned int m) -{ - /* - * Negative value, means infinite timeout: - */ - if ((int)m < 0) - return MAX_JIFFY_OFFSET; - -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) - /* - * HZ is equal to or smaller than 1000, and 1000 is a nice - * round multiple of HZ, divide with the factor between them, - * but round upwards: - */ - return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) - /* - * HZ is larger than 1000, and HZ is a nice round multiple of - * 1000 - simply multiply with the factor between them. - * - * But first make sure the multiplication result cannot - * overflow: - */ - if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return m * (HZ / MSEC_PER_SEC); -#else - /* - * Generic case - multiply, round and divide. But first - * check that if we are doing a net multiplication, that - * we wouldn't overflow: - */ - if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - - return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) - >> MSEC_TO_HZ_SHR32; -#endif -} -EXPORT_SYMBOL(msecs_to_jiffies); - -unsigned long usecs_to_jiffies(const unsigned int u) -{ - if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) - return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return u * (HZ / USEC_PER_SEC); -#else - return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) - >> USEC_TO_HZ_SHR32; -#endif -} -EXPORT_SYMBOL(usecs_to_jiffies); - -/* - * The TICK_NSEC - 1 rounds up the value to the next resolution. Note - * that a remainder subtract here would not do the right thing as the - * resolution values don't fall on second boundries. I.e. the line: - * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. - * - * Rather, we just shift the bits off the right. - * - * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec - * value to a scaled second value. - */ -unsigned long -timespec_to_jiffies(const struct timespec *value) -{ - unsigned long sec = value->tv_sec; - long nsec = value->tv_nsec + TICK_NSEC - 1; - - if (sec >= MAX_SEC_IN_JIFFIES){ - sec = MAX_SEC_IN_JIFFIES; - nsec = 0; - } - return (((u64)sec * SEC_CONVERSION) + - (((u64)nsec * NSEC_CONVERSION) >> - (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; - -} -EXPORT_SYMBOL(timespec_to_jiffies); - -void -jiffies_to_timespec(const unsigned long jiffies, struct timespec *value) -{ - /* - * Convert jiffies to nanoseconds and separate with - * one divide. - */ - u32 rem; - value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, - NSEC_PER_SEC, &rem); - value->tv_nsec = rem; -} -EXPORT_SYMBOL(jiffies_to_timespec); - -/* Same for "timeval" - * - * Well, almost. The problem here is that the real system resolution is - * in nanoseconds and the value being converted is in micro seconds. - * Also for some machines (those that use HZ = 1024, in-particular), - * there is a LARGE error in the tick size in microseconds. - - * The solution we use is to do the rounding AFTER we convert the - * microsecond part. Thus the USEC_ROUND, the bits to be shifted off. - * Instruction wise, this should cost only an additional add with carry - * instruction above the way it was done above. - */ -unsigned long -timeval_to_jiffies(const struct timeval *value) -{ - unsigned long sec = value->tv_sec; - long usec = value->tv_usec; - - if (sec >= MAX_SEC_IN_JIFFIES){ - sec = MAX_SEC_IN_JIFFIES; - usec = 0; - } - return (((u64)sec * SEC_CONVERSION) + - (((u64)usec * USEC_CONVERSION + USEC_ROUND) >> - (USEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; -} -EXPORT_SYMBOL(timeval_to_jiffies); - -void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) -{ - /* - * Convert jiffies to nanoseconds and separate with - * one divide. - */ - u32 rem; - - value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, - NSEC_PER_SEC, &rem); - value->tv_usec = rem / NSEC_PER_USEC; -} -EXPORT_SYMBOL(jiffies_to_timeval); - -/* - * Convert jiffies/jiffies_64 to clock_t and back. - */ -clock_t jiffies_to_clock_t(unsigned long x) -{ -#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 -# if HZ < USER_HZ - return x * (USER_HZ / HZ); -# else - return x / (HZ / USER_HZ); -# endif -#else - return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); -#endif -} -EXPORT_SYMBOL(jiffies_to_clock_t); - -unsigned long clock_t_to_jiffies(unsigned long x) -{ -#if (HZ % USER_HZ)==0 - if (x >= ~0UL / (HZ / USER_HZ)) - return ~0UL; - return x * (HZ / USER_HZ); -#else - /* Don't worry about loss of precision here .. */ - if (x >= ~0UL / HZ * USER_HZ) - return ~0UL; - - /* .. but do try to contain it here */ - return div_u64((u64)x * HZ, USER_HZ); -#endif -} -EXPORT_SYMBOL(clock_t_to_jiffies); - -u64 jiffies_64_to_clock_t(u64 x) -{ -#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 -# if HZ < USER_HZ - x = div_u64(x * USER_HZ, HZ); -# elif HZ > USER_HZ - x = div_u64(x, HZ / USER_HZ); -# else - /* Nothing to do */ -# endif -#else - /* - * There are better ways that don't overflow early, - * but even this doesn't overflow in hundreds of years - * in 64 bits, so.. - */ - x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); -#endif - return x; -} -EXPORT_SYMBOL(jiffies_64_to_clock_t); - -u64 nsec_to_clock_t(u64 x) -{ -#if (NSEC_PER_SEC % USER_HZ) == 0 - return div_u64(x, NSEC_PER_SEC / USER_HZ); -#elif (USER_HZ % 512) == 0 - return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); -#else - /* - * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, - * overflow after 64.99 years. - * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... - */ - return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); -#endif -} - -/** - * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 - * - * @n: nsecs in u64 - * - * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. - * And this doesn't return MAX_JIFFY_OFFSET since this function is designed - * for scheduler, not for use in device drivers to calculate timeout value. - * - * note: - * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) - * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years - */ -u64 nsecs_to_jiffies64(u64 n) -{ -#if (NSEC_PER_SEC % HZ) == 0 - /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ - return div_u64(n, NSEC_PER_SEC / HZ); -#elif (HZ % 512) == 0 - /* overflow after 292 years if HZ = 1024 */ - return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); -#else - /* - * Generic case - optimized for cases where HZ is a multiple of 3. - * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. - */ - return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); -#endif -} - -/** - * nsecs_to_jiffies - Convert nsecs in u64 to jiffies - * - * @n: nsecs in u64 - * - * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. - * And this doesn't return MAX_JIFFY_OFFSET since this function is designed - * for scheduler, not for use in device drivers to calculate timeout value. - * - * note: - * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) - * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years - */ -unsigned long nsecs_to_jiffies(u64 n) -{ - return (unsigned long)nsecs_to_jiffies64(n); -} - -/* - * Add two timespec values and do a safety check for overflow. - * It's assumed that both values are valid (>= 0) - */ -struct timespec timespec_add_safe(const struct timespec lhs, - const struct timespec rhs) -{ - struct timespec res; - - set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec, - lhs.tv_nsec + rhs.tv_nsec); - - if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec) - res.tv_sec = TIME_T_MAX; - - return res; -} |