/* * 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.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/module.h>#include <linux/timex.h>#include <linux/capability.h>#include <linux/clocksource.h>#include <linux/errno.h>#include <linux/syscalls.h>#include <linux/security.h>#include <linux/fs.h>#include <linux/slab.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;} /* * 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){ write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set();} /* * 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(struct timespec *tv, 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) { /* SMP safe, global irq locking makes it work. */ sys_tz = *tz; update_vsyscall_tz(); if (firsttime) { firsttime = 0; if (!tv) warp_clock(); } } if (tv) { /* SMP safe, again the code in arch/foo/time.c should * globally block out interrupts when it runs. */ 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 inline 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 inline 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); #ifndef CONFIG_GENERIC_TIME/* * Simulate gettimeofday using do_gettimeofday which only allows a timeval * and therefore only yields usec accuracy */void getnstimeofday(struct timespec *tv){ struct timeval x; do_gettimeofday(&x); tv->tv_sec = x.tv_sec; tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;}EXPORT_SYMBOL_GPL(getnstimeofday);#endif /* 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 longmktime(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, long nsec){ while (nsec >= NSEC_PER_SEC) { nsec -= NSEC_PER_SEC; ++sec; } while (nsec < 0) { 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);Lines 1–500 of 691. Load more
/* * 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.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/module.h> #include <linux/timex.h> #include <linux/capability.h> #include <linux/clocksource.h> #include <linux/errno.h> #include <linux/syscalls.h> #include <linux/security.h> #include <linux/fs.h> #include <linux/slab.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; } /* * 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) { write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set(); } /* * 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(struct timespec *tv, 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) { /* SMP safe, global irq locking makes it work. */ sys_tz = *tz; update_vsyscall_tz(); if (firsttime) { firsttime = 0; if (!tv) warp_clock(); } } if (tv) { /* SMP safe, again the code in arch/foo/time.c should * globally block out interrupts when it runs. */ 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 inline 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 inline 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); #ifndef CONFIG_GENERIC_TIME /* * Simulate gettimeofday using do_gettimeofday which only allows a timeval * and therefore only yields usec accuracy */ void getnstimeofday(struct timespec *tv) { struct timeval x; do_gettimeofday(&x); tv->tv_sec = x.tv_sec; tv->tv_nsec = x.tv_usec * NSEC_PER_USEC; } EXPORT_SYMBOL_GPL(getnstimeofday); #endif /* 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, long nsec) { while (nsec >= NSEC_PER_SEC) { nsec -= NSEC_PER_SEC; ++sec; } while (nsec < 0) { 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);