1/* 2 * include/linux/ktime.h 3 * 4 * ktime_t - nanosecond-resolution time format. 5 * 6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> 7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar 8 * 9 * data type definitions, declarations, prototypes and macros. 10 * 11 * Started by: Thomas Gleixner and Ingo Molnar 12 * 13 * Credits: 14 * 15 * Roman Zippel provided the ideas and primary code snippets of 16 * the ktime_t union and further simplifications of the original 17 * code. 18 * 19 * For licencing details see kernel-base/COPYING 20 */ 21#ifndef _LINUX_KTIME_H 22#define _LINUX_KTIME_H 23 24#include <asm/bug.h> 25#include <linux/jiffies.h> 26#include <linux/time.h> 27#include <linux/types.h> 28 29/** 30 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value 31 * @secs: seconds to set 32 * @nsecs: nanoseconds to set 33 * 34 * Return: The ktime_t representation of the value. 35 */ 36static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs) 37{ 38 if (unlikely(secs >= KTIME_SEC_MAX)) 39 return KTIME_MAX; 40 41 return secs * NSEC_PER_SEC + (s64)nsecs; 42} 43 44/* Subtract two ktime_t variables. rem = lhs -rhs: */ 45#define ktime_sub(lhs, rhs) ((lhs) - (rhs)) 46 47/* Add two ktime_t variables. res = lhs + rhs: */ 48#define ktime_add(lhs, rhs) ((lhs) + (rhs)) 49 50/* 51 * Same as ktime_add(), but avoids undefined behaviour on overflow; however, 52 * this means that you must check the result for overflow yourself. 53 */ 54#define ktime_add_unsafe(lhs, rhs) ((u64) (lhs) + (rhs)) 55 56/* 57 * Add a ktime_t variable and a scalar nanosecond value. 58 * res = kt + nsval: 59 */ 60#define ktime_add_ns(kt, nsval) ((kt) + (nsval)) 61 62/* 63 * Subtract a scalar nanosecod from a ktime_t variable 64 * res = kt - nsval: 65 */ 66#define ktime_sub_ns(kt, nsval) ((kt) - (nsval)) 67 68/* convert a timespec64 to ktime_t format: */ 69static inline ktime_t timespec64_to_ktime(struct timespec64 ts) 70{ 71 return ktime_set(ts.tv_sec, ts.tv_nsec); 72} 73 74/* Map the ktime_t to timespec conversion to ns_to_timespec function */ 75#define ktime_to_timespec64(kt) ns_to_timespec64((kt)) 76 77/* Convert ktime_t to nanoseconds */ 78static inline s64 ktime_to_ns(const ktime_t kt) 79{ 80 return kt; 81} 82 83/** 84 * ktime_compare - Compares two ktime_t variables for less, greater or equal 85 * @cmp1: comparable1 86 * @cmp2: comparable2 87 * 88 * Return: ... 89 * cmp1 < cmp2: return <0 90 * cmp1 == cmp2: return 0 91 * cmp1 > cmp2: return >0 92 */ 93static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) 94{ 95 if (cmp1 < cmp2) 96 return -1; 97 if (cmp1 > cmp2) 98 return 1; 99 return 0; 100} 101 102/** 103 * ktime_after - Compare if a ktime_t value is bigger than another one. 104 * @cmp1: comparable1 105 * @cmp2: comparable2 106 * 107 * Return: true if cmp1 happened after cmp2. 108 */ 109static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2) 110{ 111 return ktime_compare(cmp1, cmp2) > 0; 112} 113 114/** 115 * ktime_before - Compare if a ktime_t value is smaller than another one. 116 * @cmp1: comparable1 117 * @cmp2: comparable2 118 * 119 * Return: true if cmp1 happened before cmp2. 120 */ 121static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) 122{ 123 return ktime_compare(cmp1, cmp2) < 0; 124} 125 126#if BITS_PER_LONG < 64 127extern s64 __ktime_divns(const ktime_t kt, s64 div); 128static inline s64 ktime_divns(const ktime_t kt, s64 div) 129{ 130 /* 131 * Negative divisors could cause an inf loop, 132 * so bug out here. 133 */ 134 BUG_ON(div < 0); 135 if (__builtin_constant_p(div) && !(div >> 32)) { 136 s64 ns = kt; 137 u64 tmp = ns < 0 ? -ns : ns; 138 139 do_div(tmp, div); 140 return ns < 0 ? -tmp : tmp; 141 } else { 142 return __ktime_divns(kt, div); 143 } 144} 145#else /* BITS_PER_LONG < 64 */ 146static inline s64 ktime_divns(const ktime_t kt, s64 div) 147{ 148 /* 149 * 32-bit implementation cannot handle negative divisors, 150 * so catch them on 64bit as well. 151 */ 152 WARN_ON(div < 0); 153 return kt / div; 154} 155#endif 156 157static inline s64 ktime_to_us(const ktime_t kt) 158{ 159 return ktime_divns(kt, NSEC_PER_USEC); 160} 161 162static inline s64 ktime_to_ms(const ktime_t kt) 163{ 164 return ktime_divns(kt, NSEC_PER_MSEC); 165} 166 167static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) 168{ 169 return ktime_to_us(ktime_sub(later, earlier)); 170} 171 172static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier) 173{ 174 return ktime_to_ms(ktime_sub(later, earlier)); 175} 176 177static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) 178{ 179 return ktime_add_ns(kt, usec * NSEC_PER_USEC); 180} 181 182static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) 183{ 184 return ktime_add_ns(kt, msec * NSEC_PER_MSEC); 185} 186 187static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) 188{ 189 return ktime_sub_ns(kt, usec * NSEC_PER_USEC); 190} 191 192static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec) 193{ 194 return ktime_sub_ns(kt, msec * NSEC_PER_MSEC); 195} 196 197extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); 198 199/** 200 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64 201 * format only if the variable contains data 202 * @kt: the ktime_t variable to convert 203 * @ts: the timespec variable to store the result in 204 * 205 * Return: %true if there was a successful conversion, %false if kt was 0. 206 */ 207static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt, 208 struct timespec64 *ts) 209{ 210 if (kt) { 211 *ts = ktime_to_timespec64(kt); 212 return true; 213 } else { 214 return false; 215 } 216} 217 218#include <vdso/ktime.h> 219 220static inline ktime_t ns_to_ktime(u64 ns) 221{ 222 return ns; 223} 224 225static inline ktime_t ms_to_ktime(u64 ms) 226{ 227 return ms * NSEC_PER_MSEC; 228} 229 230# include <linux/timekeeping.h> 231 232#endif 233