at v3.10-rc1 274 lines 8.4 kB view raw
1#ifndef _LINUX_TIME_H 2#define _LINUX_TIME_H 3 4# include <linux/cache.h> 5# include <linux/seqlock.h> 6# include <linux/math64.h> 7#include <uapi/linux/time.h> 8 9extern struct timezone sys_tz; 10 11/* Parameters used to convert the timespec values: */ 12#define MSEC_PER_SEC 1000L 13#define USEC_PER_MSEC 1000L 14#define NSEC_PER_USEC 1000L 15#define NSEC_PER_MSEC 1000000L 16#define USEC_PER_SEC 1000000L 17#define NSEC_PER_SEC 1000000000L 18#define FSEC_PER_SEC 1000000000000000LL 19 20#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1) 21 22static inline int timespec_equal(const struct timespec *a, 23 const struct timespec *b) 24{ 25 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec); 26} 27 28/* 29 * lhs < rhs: return <0 30 * lhs == rhs: return 0 31 * lhs > rhs: return >0 32 */ 33static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs) 34{ 35 if (lhs->tv_sec < rhs->tv_sec) 36 return -1; 37 if (lhs->tv_sec > rhs->tv_sec) 38 return 1; 39 return lhs->tv_nsec - rhs->tv_nsec; 40} 41 42static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs) 43{ 44 if (lhs->tv_sec < rhs->tv_sec) 45 return -1; 46 if (lhs->tv_sec > rhs->tv_sec) 47 return 1; 48 return lhs->tv_usec - rhs->tv_usec; 49} 50 51extern unsigned long mktime(const unsigned int year, const unsigned int mon, 52 const unsigned int day, const unsigned int hour, 53 const unsigned int min, const unsigned int sec); 54 55extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec); 56 57/* 58 * timespec_add_safe assumes both values are positive and checks 59 * for overflow. It will return TIME_T_MAX if the reutrn would be 60 * smaller then either of the arguments. 61 */ 62extern struct timespec timespec_add_safe(const struct timespec lhs, 63 const struct timespec rhs); 64 65 66static inline struct timespec timespec_add(struct timespec lhs, 67 struct timespec rhs) 68{ 69 struct timespec ts_delta; 70 set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec, 71 lhs.tv_nsec + rhs.tv_nsec); 72 return ts_delta; 73} 74 75/* 76 * sub = lhs - rhs, in normalized form 77 */ 78static inline struct timespec timespec_sub(struct timespec lhs, 79 struct timespec rhs) 80{ 81 struct timespec ts_delta; 82 set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec, 83 lhs.tv_nsec - rhs.tv_nsec); 84 return ts_delta; 85} 86 87#define KTIME_MAX ((s64)~((u64)1 << 63)) 88#if (BITS_PER_LONG == 64) 89# define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) 90#else 91# define KTIME_SEC_MAX LONG_MAX 92#endif 93 94/* 95 * Returns true if the timespec is norm, false if denorm: 96 */ 97static inline bool timespec_valid(const struct timespec *ts) 98{ 99 /* Dates before 1970 are bogus */ 100 if (ts->tv_sec < 0) 101 return false; 102 /* Can't have more nanoseconds then a second */ 103 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) 104 return false; 105 return true; 106} 107 108static inline bool timespec_valid_strict(const struct timespec *ts) 109{ 110 if (!timespec_valid(ts)) 111 return false; 112 /* Disallow values that could overflow ktime_t */ 113 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX) 114 return false; 115 return true; 116} 117 118extern bool persistent_clock_exist; 119 120#ifdef ALWAYS_USE_PERSISTENT_CLOCK 121#define has_persistent_clock() true 122#else 123static inline bool has_persistent_clock(void) 124{ 125 return persistent_clock_exist; 126} 127#endif 128 129extern void read_persistent_clock(struct timespec *ts); 130extern void read_boot_clock(struct timespec *ts); 131extern int persistent_clock_is_local; 132extern int update_persistent_clock(struct timespec now); 133void timekeeping_init(void); 134extern int timekeeping_suspended; 135 136unsigned long get_seconds(void); 137struct timespec current_kernel_time(void); 138struct timespec __current_kernel_time(void); /* does not take xtime_lock */ 139struct timespec get_monotonic_coarse(void); 140void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, 141 struct timespec *wtom, struct timespec *sleep); 142void timekeeping_inject_sleeptime(struct timespec *delta); 143 144#define CURRENT_TIME (current_kernel_time()) 145#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 }) 146 147/* Some architectures do not supply their own clocksource. 148 * This is mainly the case in architectures that get their 149 * inter-tick times by reading the counter on their interval 150 * timer. Since these timers wrap every tick, they're not really 151 * useful as clocksources. Wrapping them to act like one is possible 152 * but not very efficient. So we provide a callout these arches 153 * can implement for use with the jiffies clocksource to provide 154 * finer then tick granular time. 155 */ 156#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET 157extern u32 (*arch_gettimeoffset)(void); 158#endif 159 160extern void do_gettimeofday(struct timeval *tv); 161extern int do_settimeofday(const struct timespec *tv); 162extern int do_sys_settimeofday(const struct timespec *tv, 163 const struct timezone *tz); 164#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts) 165extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags); 166struct itimerval; 167extern int do_setitimer(int which, struct itimerval *value, 168 struct itimerval *ovalue); 169extern unsigned int alarm_setitimer(unsigned int seconds); 170extern int do_getitimer(int which, struct itimerval *value); 171extern int __getnstimeofday(struct timespec *tv); 172extern void getnstimeofday(struct timespec *tv); 173extern void getrawmonotonic(struct timespec *ts); 174extern void getnstime_raw_and_real(struct timespec *ts_raw, 175 struct timespec *ts_real); 176extern void getboottime(struct timespec *ts); 177extern void monotonic_to_bootbased(struct timespec *ts); 178extern void get_monotonic_boottime(struct timespec *ts); 179 180extern struct timespec timespec_trunc(struct timespec t, unsigned gran); 181extern int timekeeping_valid_for_hres(void); 182extern u64 timekeeping_max_deferment(void); 183extern int timekeeping_inject_offset(struct timespec *ts); 184extern s32 timekeeping_get_tai_offset(void); 185extern void timekeeping_set_tai_offset(s32 tai_offset); 186extern void timekeeping_clocktai(struct timespec *ts); 187 188struct tms; 189extern void do_sys_times(struct tms *); 190 191/* 192 * Similar to the struct tm in userspace <time.h>, but it needs to be here so 193 * that the kernel source is self contained. 194 */ 195struct tm { 196 /* 197 * the number of seconds after the minute, normally in the range 198 * 0 to 59, but can be up to 60 to allow for leap seconds 199 */ 200 int tm_sec; 201 /* the number of minutes after the hour, in the range 0 to 59*/ 202 int tm_min; 203 /* the number of hours past midnight, in the range 0 to 23 */ 204 int tm_hour; 205 /* the day of the month, in the range 1 to 31 */ 206 int tm_mday; 207 /* the number of months since January, in the range 0 to 11 */ 208 int tm_mon; 209 /* the number of years since 1900 */ 210 long tm_year; 211 /* the number of days since Sunday, in the range 0 to 6 */ 212 int tm_wday; 213 /* the number of days since January 1, in the range 0 to 365 */ 214 int tm_yday; 215}; 216 217void time_to_tm(time_t totalsecs, int offset, struct tm *result); 218 219/** 220 * timespec_to_ns - Convert timespec to nanoseconds 221 * @ts: pointer to the timespec variable to be converted 222 * 223 * Returns the scalar nanosecond representation of the timespec 224 * parameter. 225 */ 226static inline s64 timespec_to_ns(const struct timespec *ts) 227{ 228 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec; 229} 230 231/** 232 * timeval_to_ns - Convert timeval to nanoseconds 233 * @ts: pointer to the timeval variable to be converted 234 * 235 * Returns the scalar nanosecond representation of the timeval 236 * parameter. 237 */ 238static inline s64 timeval_to_ns(const struct timeval *tv) 239{ 240 return ((s64) tv->tv_sec * NSEC_PER_SEC) + 241 tv->tv_usec * NSEC_PER_USEC; 242} 243 244/** 245 * ns_to_timespec - Convert nanoseconds to timespec 246 * @nsec: the nanoseconds value to be converted 247 * 248 * Returns the timespec representation of the nsec parameter. 249 */ 250extern struct timespec ns_to_timespec(const s64 nsec); 251 252/** 253 * ns_to_timeval - Convert nanoseconds to timeval 254 * @nsec: the nanoseconds value to be converted 255 * 256 * Returns the timeval representation of the nsec parameter. 257 */ 258extern struct timeval ns_to_timeval(const s64 nsec); 259 260/** 261 * timespec_add_ns - Adds nanoseconds to a timespec 262 * @a: pointer to timespec to be incremented 263 * @ns: unsigned nanoseconds value to be added 264 * 265 * This must always be inlined because its used from the x86-64 vdso, 266 * which cannot call other kernel functions. 267 */ 268static __always_inline void timespec_add_ns(struct timespec *a, u64 ns) 269{ 270 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns); 271 a->tv_nsec = ns; 272} 273 274#endif