http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/linux/ktime.h

/* * include/linux/ktime.h * * ktime_t - nanosecond-resolution time format. * * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar * * data type definitions, declarations, prototypes and macros. * * Started by: Thomas Gleixner and Ingo Molnar * * Credits: * * Roman Zippel provided the ideas and primary code snippets of * the ktime_t union and further simplifications of the original * code. * * For licencing details see kernel-base/COPYING */ #ifndef _LINUX_KTIME_H #define _LINUX_KTIME_H #include <linux/time.h> #include <linux/jiffies.h> /* * ktime_t: * * On 64-bit CPUs a single 64-bit variable is used to store the hrtimers * internal representation of time values in scalar nanoseconds. The * design plays out best on 64-bit CPUs, where most conversions are * NOPs and most arithmetic ktime_t operations are plain arithmetic * operations. * * On 32-bit CPUs an optimized representation of the timespec structure * is used to avoid expensive conversions from and to timespecs. The * endian-aware order of the tv struct members is choosen to allow * mathematical operations on the tv64 member of the union too, which * for certain operations produces better code. * * For architectures with efficient support for 64/32-bit conversions the * plain scalar nanosecond based representation can be selected by the * config switch CONFIG_KTIME_SCALAR. */ typedef union { s64 tv64; #if BITS_PER_LONG != 64 && !defined(CONFIG_KTIME_SCALAR) struct { # ifdef __BIG_ENDIAN s32 sec, nsec; # else s32 nsec, sec; # endif } tv; #endif } ktime_t; #define KTIME_MAX (~((u64)1 << 63)) /* * ktime_t definitions when using the 64-bit scalar representation: */ #if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR) /* Define a ktime_t variable and initialize it to zero: */ #define DEFINE_KTIME(kt) ktime_t kt = { .tv64 = 0 } /** * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value * * @secs: seconds to set * @nsecs: nanoseconds to set * * Return the ktime_t representation of the value */ static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) { return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs }; } /* Subtract two ktime_t variables. rem = lhs -rhs: */ #define ktime_sub(lhs, rhs) \ ({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; }) /* Add two ktime_t variables. res = lhs + rhs: */ #define ktime_add(lhs, rhs) \ ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; }) /* * Add a ktime_t variable and a scalar nanosecond value. * res = kt + nsval: */ #define ktime_add_ns(kt, nsval) \ ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; }) /* convert a timespec to ktime_t format: */ static inline ktime_t timespec_to_ktime(struct timespec ts) { return ktime_set(ts.tv_sec, ts.tv_nsec); } /* convert a timeval to ktime_t format: */ static inline ktime_t timeval_to_ktime(struct timeval tv) { return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); } /* Map the ktime_t to timespec conversion to ns_to_timespec function */ #define ktime_to_timespec(kt) ns_to_timespec((kt).tv64) /* Map the ktime_t to timeval conversion to ns_to_timeval function */ #define ktime_to_timeval(kt) ns_to_timeval((kt).tv64) /* Map the ktime_t to clock_t conversion to the inline in jiffies.h: */ #define ktime_to_clock_t(kt) nsec_to_clock_t((kt).tv64) /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ #define ktime_to_ns(kt) ((kt).tv64) #else /* * Helper macros/inlines to get the ktime_t math right in the timespec * representation. The macros are sometimes ugly - their actual use is * pretty okay-ish, given the circumstances. We do all this for * performance reasons. The pure scalar nsec_t based code was nice and * simple, but created too many 64-bit / 32-bit conversions and divisions. * * Be especially aware that negative values are represented in a way * that the tv.sec field is negative and the tv.nsec field is greater * or equal to zero but less than nanoseconds per second. This is the * same representation which is used by timespecs. * * tv.sec < 0 and 0 >= tv.nsec < NSEC_PER_SEC */ /* Define a ktime_t variable and initialize it to zero: */ #define DEFINE_KTIME(kt) ktime_t kt = { .tv64 = 0 } /* Set a ktime_t variable to a value in sec/nsec representation: */ static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) { return (ktime_t) { .tv = { .sec = secs, .nsec = nsecs } }; } /** * ktime_sub - subtract two ktime_t variables * * @lhs: minuend * @rhs: subtrahend * * Returns the remainder of the substraction */ static inline ktime_t ktime_sub(const ktime_t lhs, const ktime_t rhs) { ktime_t res; res.tv64 = lhs.tv64 - rhs.tv64; if (res.tv.nsec < 0) res.tv.nsec += NSEC_PER_SEC; return res; } /** * ktime_add - add two ktime_t variables * * @add1: addend1 * @add2: addend2 * * Returns the sum of addend1 and addend2 */ static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2) { ktime_t res; res.tv64 = add1.tv64 + add2.tv64; /* * performance trick: the (u32) -NSEC gives 0x00000000Fxxxxxxx * so we subtract NSEC_PER_SEC and add 1 to the upper 32 bit. * * it's equivalent to: * tv.nsec -= NSEC_PER_SEC * tv.sec ++; */ if (res.tv.nsec >= NSEC_PER_SEC) res.tv64 += (u32)-NSEC_PER_SEC; return res; } /** * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable * * @kt: addend * @nsec: the scalar nsec value to add * * Returns the sum of kt and nsec in ktime_t format */ extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec); /** * timespec_to_ktime - convert a timespec to ktime_t format * * @ts: the timespec variable to convert * * Returns a ktime_t variable with the converted timespec value */ static inline ktime_t timespec_to_ktime(const struct timespec ts) { return (ktime_t) { .tv = { .sec = (s32)ts.tv_sec, .nsec = (s32)ts.tv_nsec } }; } /** * timeval_to_ktime - convert a timeval to ktime_t format * * @tv: the timeval variable to convert * * Returns a ktime_t variable with the converted timeval value */ static inline ktime_t timeval_to_ktime(const struct timeval tv) { return (ktime_t) { .tv = { .sec = (s32)tv.tv_sec, .nsec = (s32)tv.tv_usec * 1000 } }; } /** * ktime_to_timespec - convert a ktime_t variable to timespec format * * @kt: the ktime_t variable to convert * * Returns the timespec representation of the ktime value */ static inline struct timespec ktime_to_timespec(const ktime_t kt) { return (struct timespec) { .tv_sec = (time_t) kt.tv.sec, .tv_nsec = (long) kt.tv.nsec }; } /** * ktime_to_timeval - convert a ktime_t variable to timeval format * * @kt: the ktime_t variable to convert * * Returns the timeval representation of the ktime value */ static inline struct timeval ktime_to_timeval(const ktime_t kt) { return (struct timeval) { .tv_sec = (time_t) kt.tv.sec, .tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) }; } /** * ktime_to_clock_t - convert a ktime_t variable to clock_t format * @kt: the ktime_t variable to convert * * Returns a clock_t variable with the converted value */ static inline clock_t ktime_to_clock_t(const ktime_t kt) { return nsec_to_clock_t( (u64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec); } /** * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds * @kt: the ktime_t variable to convert * * Returns the scalar nanoseconds representation of kt */ static inline u64 ktime_to_ns(const ktime_t kt) { return (u64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec; } #endif /* * The resolution of the clocks. The resolution value is returned in * the clock_getres() system call to give application programmers an * idea of the (in)accuracy of timers. Timer values are rounded up to * this resolution values. */ #define KTIME_REALTIME_RES (ktime_t){ .tv64 = TICK_NSEC } #define KTIME_MONOTONIC_RES (ktime_t){ .tv64 = TICK_NSEC } /* Get the monotonic time in timespec format: */ extern void ktime_get_ts(struct timespec *ts); /* Get the real (wall-) time in timespec format: */ #define ktime_get_real_ts(ts) getnstimeofday(ts) #endif