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 <linux/time.h> 25 #include <linux/jiffies.h> 26 27 /* Nanosecond scalar representation for kernel time values */ 28 typedef s64 ktime_t; 29 30 /** 31 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value 32 * @secs: seconds to set 33 * @nsecs: nanoseconds to set 34 * 35 * Return: The ktime_t representation of the value. 36 */ 37 static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs) 38 { 39 if (unlikely(secs >= KTIME_SEC_MAX)) 40 return KTIME_MAX; 41 42 return secs * NSEC_PER_SEC + (s64)nsecs; 43 } 44 45 /* Subtract two ktime_t variables. rem = lhs -rhs: */ 46 #define ktime_sub(lhs, rhs) ((lhs) - (rhs)) 47 48 /* Add two ktime_t variables. res = lhs + rhs: */ 49 #define ktime_add(lhs, rhs) ((lhs) + (rhs)) 50 51 /* 52 * Same as ktime_add(), but avoids undefined behaviour on overflow; however, 53 * this means that you must check the result for overflow yourself. 54 */ 55 #define ktime_add_unsafe(lhs, rhs) ((u64) (lhs) + (rhs)) 56 57 /* 58 * Add a ktime_t variable and a scalar nanosecond value. 59 * res = kt + nsval: 60 */ 61 #define ktime_add_ns(kt, nsval) ((kt) + (nsval)) 62 63 /* 64 * Subtract a scalar nanosecod from a ktime_t variable 65 * res = kt - nsval: 66 */ 67 #define ktime_sub_ns(kt, nsval) ((kt) - (nsval)) 68 69 /* convert a timespec to ktime_t format: */ 70 static inline ktime_t timespec_to_ktime(struct timespec ts) 71 { 72 return ktime_set(ts.tv_sec, ts.tv_nsec); 73 } 74 75 /* convert a timespec64 to ktime_t format: */ 76 static inline ktime_t timespec64_to_ktime(struct timespec64 ts) 77 { 78 return ktime_set(ts.tv_sec, ts.tv_nsec); 79 } 80 81 /* convert a timeval to ktime_t format: */ 82 static inline ktime_t timeval_to_ktime(struct timeval tv) 83 { 84 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 85 } 86 87 /* Map the ktime_t to timespec conversion to ns_to_timespec function */ 88 #define ktime_to_timespec(kt) ns_to_timespec((kt)) 89 90 /* Map the ktime_t to timespec conversion to ns_to_timespec function */ 91 #define ktime_to_timespec64(kt) ns_to_timespec64((kt)) 92 93 /* Map the ktime_t to timeval conversion to ns_to_timeval function */ 94 #define ktime_to_timeval(kt) ns_to_timeval((kt)) 95 96 /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ 97 #define ktime_to_ns(kt) (kt) 98 99 /** 100 * ktime_compare - Compares two ktime_t variables for less, greater or equal 101 * @cmp1: comparable1 102 * @cmp2: comparable2 103 * 104 * Return: ... 105 * cmp1 < cmp2: return <0 106 * cmp1 == cmp2: return 0 107 * cmp1 > cmp2: return >0 108 */ 109 static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) 110 { 111 if (cmp1 < cmp2) 112 return -1; 113 if (cmp1 > cmp2) 114 return 1; 115 return 0; 116 } 117 118 /** 119 * ktime_after - Compare if a ktime_t value is bigger than another one. 120 * @cmp1: comparable1 121 * @cmp2: comparable2 122 * 123 * Return: true if cmp1 happened after cmp2. 124 */ 125 static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2) 126 { 127 return ktime_compare(cmp1, cmp2) > 0; 128 } 129 130 /** 131 * ktime_before - Compare if a ktime_t value is smaller than another one. 132 * @cmp1: comparable1 133 * @cmp2: comparable2 134 * 135 * Return: true if cmp1 happened before cmp2. 136 */ 137 static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) 138 { 139 return ktime_compare(cmp1, cmp2) < 0; 140 } 141 142 #if BITS_PER_LONG < 64 143 extern s64 __ktime_divns(const ktime_t kt, s64 div); 144 static inline s64 ktime_divns(const ktime_t kt, s64 div) 145 { 146 /* 147 * Negative divisors could cause an inf loop, 148 * so bug out here. 149 */ 150 BUG_ON(div < 0); 151 if (__builtin_constant_p(div) && !(div >> 32)) { 152 s64 ns = kt; 153 u64 tmp = ns < 0 ? -ns : ns; 154 155 do_div(tmp, div); 156 return ns < 0 ? -tmp : tmp; 157 } else { 158 return __ktime_divns(kt, div); 159 } 160 } 161 #else /* BITS_PER_LONG < 64 */ 162 static inline s64 ktime_divns(const ktime_t kt, s64 div) 163 { 164 /* 165 * 32-bit implementation cannot handle negative divisors, 166 * so catch them on 64bit as well. 167 */ 168 WARN_ON(div < 0); 169 return kt / div; 170 } 171 #endif 172 173 static inline s64 ktime_to_us(const ktime_t kt) 174 { 175 return ktime_divns(kt, NSEC_PER_USEC); 176 } 177 178 static inline s64 ktime_to_ms(const ktime_t kt) 179 { 180 return ktime_divns(kt, NSEC_PER_MSEC); 181 } 182 183 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) 184 { 185 return ktime_to_us(ktime_sub(later, earlier)); 186 } 187 188 static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier) 189 { 190 return ktime_to_ms(ktime_sub(later, earlier)); 191 } 192 193 static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) 194 { 195 return ktime_add_ns(kt, usec * NSEC_PER_USEC); 196 } 197 198 static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) 199 { 200 return ktime_add_ns(kt, msec * NSEC_PER_MSEC); 201 } 202 203 static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) 204 { 205 return ktime_sub_ns(kt, usec * NSEC_PER_USEC); 206 } 207 208 static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec) 209 { 210 return ktime_sub_ns(kt, msec * NSEC_PER_MSEC); 211 } 212 213 extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); 214 215 /** 216 * ktime_to_timespec_cond - convert a ktime_t variable to timespec 217 * format only if the variable contains data 218 * @kt: the ktime_t variable to convert 219 * @ts: the timespec variable to store the result in 220 * 221 * Return: %true if there was a successful conversion, %false if kt was 0. 222 */ 223 static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt, 224 struct timespec *ts) 225 { 226 if (kt) { 227 *ts = ktime_to_timespec(kt); 228 return true; 229 } else { 230 return false; 231 } 232 } 233 234 /** 235 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64 236 * format only if the variable contains data 237 * @kt: the ktime_t variable to convert 238 * @ts: the timespec variable to store the result in 239 * 240 * Return: %true if there was a successful conversion, %false if kt was 0. 241 */ 242 static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt, 243 struct timespec64 *ts) 244 { 245 if (kt) { 246 *ts = ktime_to_timespec64(kt); 247 return true; 248 } else { 249 return false; 250 } 251 } 252 253 /* 254 * The resolution of the clocks. The resolution value is returned in 255 * the clock_getres() system call to give application programmers an 256 * idea of the (in)accuracy of timers. Timer values are rounded up to 257 * this resolution values. 258 */ 259 #define LOW_RES_NSEC TICK_NSEC 260 #define KTIME_LOW_RES (LOW_RES_NSEC) 261 262 static inline ktime_t ns_to_ktime(u64 ns) 263 { 264 return ns; 265 } 266 267 static inline ktime_t ms_to_ktime(u64 ms) 268 { 269 return ms * NSEC_PER_MSEC; 270 } 271 272 # include <linux/timekeeping.h> 273 # include <linux/timekeeping32.h> 274 275 #endif 276