| /* |
| * 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. |
| */ |
| union ktime { |
| 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 |
| }; |
| |
| typedef union ktime ktime_t; /* Kill this */ |
| |
| #define KTIME_MAX ((s64)~((u64)1 << 63)) |
| #if (BITS_PER_LONG == 64) |
| # define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC) |
| #else |
| # define KTIME_SEC_MAX LONG_MAX |
| #endif |
| |
| /* |
| * ktime_t definitions when using the 64-bit scalar representation: |
| */ |
| |
| #if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR) |
| |
| /** |
| * 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) |
| { |
| #if (BITS_PER_LONG == 64) |
| if (unlikely(secs >= KTIME_SEC_MAX)) |
| return (ktime_t){ .tv64 = KTIME_MAX }; |
| #endif |
| 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) |
| |
| /* 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 |
| */ |
| |
| /* 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 @add1 and @add2. |
| */ |
| 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_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 s64 ktime_to_ns(const ktime_t kt) |
| { |
| return (s64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec; |
| } |
| |
| #endif |
| |
| /** |
| * ktime_equal - Compares two ktime_t variables to see if they are equal |
| * @cmp1: comparable1 |
| * @cmp2: comparable2 |
| * |
| * Compare two ktime_t variables, returns 1 if equal |
| */ |
| static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2) |
| { |
| return cmp1.tv64 == cmp2.tv64; |
| } |
| |
| static inline s64 ktime_to_us(const ktime_t kt) |
| { |
| struct timeval tv = ktime_to_timeval(kt); |
| return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec; |
| } |
| |
| /* |
| * 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_LOW_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 |