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 /* 28 * ktime_t: 29 * 30 * A single 64-bit variable is used to store the hrtimers 31 * internal representation of time values in scalar nanoseconds. The 32 * design plays out best on 64-bit CPUs, where most conversions are 33 * NOPs and most arithmetic ktime_t operations are plain arithmetic 34 * operations. 35 * 36 */ 37 union ktime { 38 s64 tv64; 39 }; 40 41 typedef union ktime ktime_t; /* Kill this */ 42 43 /** 44 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value 45 * @secs: seconds to set 46 * @nsecs: nanoseconds to set 47 * 48 * Return: The ktime_t representation of the value. 49 */ 50 static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs) 51 { 52 if (unlikely(secs >= KTIME_SEC_MAX)) 53 return (ktime_t){ .tv64 = KTIME_MAX }; 54 55 return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs }; 56 } 57 58 /* Subtract two ktime_t variables. rem = lhs -rhs: */ 59 #define ktime_sub(lhs, rhs) \ 60 ({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; }) 61 62 /* Add two ktime_t variables. res = lhs + rhs: */ 63 #define ktime_add(lhs, rhs) \ 64 ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; }) 65 66 /* 67 * Add a ktime_t variable and a scalar nanosecond value. 68 * res = kt + nsval: 69 */ 70 #define ktime_add_ns(kt, nsval) \ 71 ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; }) 72 73 /* 74 * Subtract a scalar nanosecod from a ktime_t variable 75 * res = kt - nsval: 76 */ 77 #define ktime_sub_ns(kt, nsval) \ 78 ({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; }) 79 80 /* convert a timespec to ktime_t format: */ 81 static inline ktime_t timespec_to_ktime(struct timespec ts) 82 { 83 return ktime_set(ts.tv_sec, ts.tv_nsec); 84 } 85 86 /* convert a timespec64 to ktime_t format: */ 87 static inline ktime_t timespec64_to_ktime(struct timespec64 ts) 88 { 89 return ktime_set(ts.tv_sec, ts.tv_nsec); 90 } 91 92 /* convert a timeval to ktime_t format: */ 93 static inline ktime_t timeval_to_ktime(struct timeval tv) 94 { 95 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 96 } 97 98 /* Map the ktime_t to timespec conversion to ns_to_timespec function */ 99 #define ktime_to_timespec(kt) ns_to_timespec((kt).tv64) 100 101 /* Map the ktime_t to timespec conversion to ns_to_timespec function */ 102 #define ktime_to_timespec64(kt) ns_to_timespec64((kt).tv64) 103 104 /* Map the ktime_t to timeval conversion to ns_to_timeval function */ 105 #define ktime_to_timeval(kt) ns_to_timeval((kt).tv64) 106 107 /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ 108 #define ktime_to_ns(kt) ((kt).tv64) 109 110 111 /** 112 * ktime_equal - Compares two ktime_t variables to see if they are equal 113 * @cmp1: comparable1 114 * @cmp2: comparable2 115 * 116 * Compare two ktime_t variables. 117 * 118 * Return: 1 if equal. 119 */ 120 static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2) 121 { 122 return cmp1.tv64 == cmp2.tv64; 123 } 124 125 /** 126 * ktime_compare - Compares two ktime_t variables for less, greater or equal 127 * @cmp1: comparable1 128 * @cmp2: comparable2 129 * 130 * Return: ... 131 * cmp1 < cmp2: return <0 132 * cmp1 == cmp2: return 0 133 * cmp1 > cmp2: return >0 134 */ 135 static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) 136 { 137 if (cmp1.tv64 < cmp2.tv64) 138 return -1; 139 if (cmp1.tv64 > cmp2.tv64) 140 return 1; 141 return 0; 142 } 143 144 /** 145 * ktime_after - Compare if a ktime_t value is bigger than another one. 146 * @cmp1: comparable1 147 * @cmp2: comparable2 148 * 149 * Return: true if cmp1 happened after cmp2. 150 */ 151 static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2) 152 { 153 return ktime_compare(cmp1, cmp2) > 0; 154 } 155 156 /** 157 * ktime_before - Compare if a ktime_t value is smaller than another one. 158 * @cmp1: comparable1 159 * @cmp2: comparable2 160 * 161 * Return: true if cmp1 happened before cmp2. 162 */ 163 static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) 164 { 165 return ktime_compare(cmp1, cmp2) < 0; 166 } 167 168 #if BITS_PER_LONG < 64 169 extern s64 __ktime_divns(const ktime_t kt, s64 div); 170 static inline s64 ktime_divns(const ktime_t kt, s64 div) 171 { 172 /* 173 * Negative divisors could cause an inf loop, 174 * so bug out here. 175 */ 176 BUG_ON(div < 0); 177 if (__builtin_constant_p(div) && !(div >> 32)) { 178 s64 ns = kt.tv64; 179 u64 tmp = ns < 0 ? -ns : ns; 180 181 do_div(tmp, div); 182 return ns < 0 ? -tmp : tmp; 183 } else { 184 return __ktime_divns(kt, div); 185 } 186 } 187 #else /* BITS_PER_LONG < 64 */ 188 static inline s64 ktime_divns(const ktime_t kt, s64 div) 189 { 190 /* 191 * 32-bit implementation cannot handle negative divisors, 192 * so catch them on 64bit as well. 193 */ 194 WARN_ON(div < 0); 195 return kt.tv64 / div; 196 } 197 #endif 198 199 static inline s64 ktime_to_us(const ktime_t kt) 200 { 201 return ktime_divns(kt, NSEC_PER_USEC); 202 } 203 204 static inline s64 ktime_to_ms(const ktime_t kt) 205 { 206 return ktime_divns(kt, NSEC_PER_MSEC); 207 } 208 209 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) 210 { 211 return ktime_to_us(ktime_sub(later, earlier)); 212 } 213 214 static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier) 215 { 216 return ktime_to_ms(ktime_sub(later, earlier)); 217 } 218 219 static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) 220 { 221 return ktime_add_ns(kt, usec * NSEC_PER_USEC); 222 } 223 224 static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) 225 { 226 return ktime_add_ns(kt, msec * NSEC_PER_MSEC); 227 } 228 229 static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) 230 { 231 return ktime_sub_ns(kt, usec * NSEC_PER_USEC); 232 } 233 234 extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); 235 236 /** 237 * ktime_to_timespec_cond - convert a ktime_t variable to timespec 238 * format only if the variable contains data 239 * @kt: the ktime_t variable to convert 240 * @ts: the timespec variable to store the result in 241 * 242 * Return: %true if there was a successful conversion, %false if kt was 0. 243 */ 244 static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt, 245 struct timespec *ts) 246 { 247 if (kt.tv64) { 248 *ts = ktime_to_timespec(kt); 249 return true; 250 } else { 251 return false; 252 } 253 } 254 255 /** 256 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64 257 * format only if the variable contains data 258 * @kt: the ktime_t variable to convert 259 * @ts: the timespec variable to store the result in 260 * 261 * Return: %true if there was a successful conversion, %false if kt was 0. 262 */ 263 static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt, 264 struct timespec64 *ts) 265 { 266 if (kt.tv64) { 267 *ts = ktime_to_timespec64(kt); 268 return true; 269 } else { 270 return false; 271 } 272 } 273 274 /* 275 * The resolution of the clocks. The resolution value is returned in 276 * the clock_getres() system call to give application programmers an 277 * idea of the (in)accuracy of timers. Timer values are rounded up to 278 * this resolution values. 279 */ 280 #define LOW_RES_NSEC TICK_NSEC 281 #define KTIME_LOW_RES (ktime_t){ .tv64 = LOW_RES_NSEC } 282 283 static inline ktime_t ns_to_ktime(u64 ns) 284 { 285 static const ktime_t ktime_zero = { .tv64 = 0 }; 286 287 return ktime_add_ns(ktime_zero, ns); 288 } 289 290 static inline ktime_t ms_to_ktime(u64 ms) 291 { 292 static const ktime_t ktime_zero = { .tv64 = 0 }; 293 294 return ktime_add_ms(ktime_zero, ms); 295 } 296 297 # include <linux/timekeeping.h> 298 299 #endif 300