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 */ 97 static inline s64 ktime_to_ns(const ktime_t kt) 98 { 99 return kt; 100 } 101 102 /** 103 * ktime_compare - Compares two ktime_t variables for less, greater or equal 104 * @cmp1: comparable1 105 * @cmp2: comparable2 106 * 107 * Return: ... 108 * cmp1 < cmp2: return <0 109 * cmp1 == cmp2: return 0 110 * cmp1 > cmp2: return >0 111 */ 112 static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) 113 { 114 if (cmp1 < cmp2) 115 return -1; 116 if (cmp1 > cmp2) 117 return 1; 118 return 0; 119 } 120 121 /** 122 * ktime_after - Compare if a ktime_t value is bigger than another one. 123 * @cmp1: comparable1 124 * @cmp2: comparable2 125 * 126 * Return: true if cmp1 happened after cmp2. 127 */ 128 static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2) 129 { 130 return ktime_compare(cmp1, cmp2) > 0; 131 } 132 133 /** 134 * ktime_before - Compare if a ktime_t value is smaller than another one. 135 * @cmp1: comparable1 136 * @cmp2: comparable2 137 * 138 * Return: true if cmp1 happened before cmp2. 139 */ 140 static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) 141 { 142 return ktime_compare(cmp1, cmp2) < 0; 143 } 144 145 #if BITS_PER_LONG < 64 146 extern s64 __ktime_divns(const ktime_t kt, s64 div); 147 static inline s64 ktime_divns(const ktime_t kt, s64 div) 148 { 149 /* 150 * Negative divisors could cause an inf loop, 151 * so bug out here. 152 */ 153 BUG_ON(div < 0); 154 if (__builtin_constant_p(div) && !(div >> 32)) { 155 s64 ns = kt; 156 u64 tmp = ns < 0 ? -ns : ns; 157 158 do_div(tmp, div); 159 return ns < 0 ? -tmp : tmp; 160 } else { 161 return __ktime_divns(kt, div); 162 } 163 } 164 #else /* BITS_PER_LONG < 64 */ 165 static inline s64 ktime_divns(const ktime_t kt, s64 div) 166 { 167 /* 168 * 32-bit implementation cannot handle negative divisors, 169 * so catch them on 64bit as well. 170 */ 171 WARN_ON(div < 0); 172 return kt / div; 173 } 174 #endif 175 176 static inline s64 ktime_to_us(const ktime_t kt) 177 { 178 return ktime_divns(kt, NSEC_PER_USEC); 179 } 180 181 static inline s64 ktime_to_ms(const ktime_t kt) 182 { 183 return ktime_divns(kt, NSEC_PER_MSEC); 184 } 185 186 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) 187 { 188 return ktime_to_us(ktime_sub(later, earlier)); 189 } 190 191 static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier) 192 { 193 return ktime_to_ms(ktime_sub(later, earlier)); 194 } 195 196 static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) 197 { 198 return ktime_add_ns(kt, usec * NSEC_PER_USEC); 199 } 200 201 static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) 202 { 203 return ktime_add_ns(kt, msec * NSEC_PER_MSEC); 204 } 205 206 static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) 207 { 208 return ktime_sub_ns(kt, usec * NSEC_PER_USEC); 209 } 210 211 static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec) 212 { 213 return ktime_sub_ns(kt, msec * NSEC_PER_MSEC); 214 } 215 216 extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); 217 218 /** 219 * ktime_to_timespec_cond - convert a ktime_t variable to timespec 220 * format only if the variable contains data 221 * @kt: the ktime_t variable to convert 222 * @ts: the timespec variable to store the result in 223 * 224 * Return: %true if there was a successful conversion, %false if kt was 0. 225 */ 226 static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt, 227 struct timespec *ts) 228 { 229 if (kt) { 230 *ts = ktime_to_timespec(kt); 231 return true; 232 } else { 233 return false; 234 } 235 } 236 237 /** 238 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64 239 * format only if the variable contains data 240 * @kt: the ktime_t variable to convert 241 * @ts: the timespec variable to store the result in 242 * 243 * Return: %true if there was a successful conversion, %false if kt was 0. 244 */ 245 static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt, 246 struct timespec64 *ts) 247 { 248 if (kt) { 249 *ts = ktime_to_timespec64(kt); 250 return true; 251 } else { 252 return false; 253 } 254 } 255 256 /* 257 * The resolution of the clocks. The resolution value is returned in 258 * the clock_getres() system call to give application programmers an 259 * idea of the (in)accuracy of timers. Timer values are rounded up to 260 * this resolution values. 261 */ 262 #define LOW_RES_NSEC TICK_NSEC 263 #define KTIME_LOW_RES (LOW_RES_NSEC) 264 265 static inline ktime_t ns_to_ktime(u64 ns) 266 { 267 return ns; 268 } 269 270 static inline ktime_t ms_to_ktime(u64 ms) 271 { 272 return ms * NSEC_PER_MSEC; 273 } 274 275 # include <linux/timekeeping.h> 276 # include <linux/timekeeping32.h> 277 278 #endif 279