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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: * On 64-bit CPUs 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: * On 32-bit CPUs an optimized representation of the timespec structure 37: * is used to avoid expensive conversions from and to timespecs. The 38: * endian-aware order of the tv struct members is chosen to allow 39: * mathematical operations on the tv64 member of the union too, which 40: * for certain operations produces better code. 41: * 42: * For architectures with efficient support for 64/32-bit conversions the 43: * plain scalar nanosecond based representation can be selected by the 44: * config switch CONFIG_KTIME_SCALAR. 45: */ 46: union ktime { 47: s64 tv64; 48: #if BITS_PER_LONG != 64 && !defined(CONFIG_KTIME_SCALAR) 49: struct { 50: # ifdef __BIG_ENDIAN 51: s32 sec, nsec; 52: # else 53: s32 nsec, sec; 54: # endif 55: } tv; 56: #endif 57: }; 58: 59: typedef union ktime ktime_t; /* Kill this */ 60: 61: /* 62: * ktime_t definitions when using the 64-bit scalar representation: 63: */ 64: 65: #if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR) 66: 67: /** 68: * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value 69: * @secs: seconds to set 70: * @nsecs: nanoseconds to set 71: * 72: * Return: The ktime_t representation of the value. 73: */ 74: static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) 75: { 76: #if (BITS_PER_LONG == 64) 77: if (unlikely(secs >= KTIME_SEC_MAX)) 78: return (ktime_t){ .tv64 = KTIME_MAX }; 79: #endif 80: return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs }; 81: } 82: 83: /* Subtract two ktime_t variables. rem = lhs -rhs: */ 84: #define ktime_sub(lhs, rhs) \ 85: ({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; }) 86: 87: /* Add two ktime_t variables. res = lhs + rhs: */ 88: #define ktime_add(lhs, rhs) \ 89: ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; }) 90: 91: /* 92: * Add a ktime_t variable and a scalar nanosecond value. 93: * res = kt + nsval: 94: */ 95: #define ktime_add_ns(kt, nsval) \ 96: ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; }) 97: 98: /* 99: * Subtract a scalar nanosecod from a ktime_t variable 100: * res = kt - nsval: 101: */ 102: #define ktime_sub_ns(kt, nsval) \ 103: ({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; }) 104: 105: /* convert a timespec to ktime_t format: */ 106: static inline ktime_t timespec_to_ktime(struct timespec ts) 107: { 108: return ktime_set(ts.tv_sec, ts.tv_nsec); 109: } 110: 111: /* convert a timeval to ktime_t format: */ 112: static inline ktime_t timeval_to_ktime(struct timeval tv) 113: { 114: return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); 115: } 116: 117: /* Map the ktime_t to timespec conversion to ns_to_timespec function */ 118: #define ktime_to_timespec(kt) ns_to_timespec((kt).tv64) 119: 120: /* Map the ktime_t to timeval conversion to ns_to_timeval function */ 121: #define ktime_to_timeval(kt) ns_to_timeval((kt).tv64) 122: 123: /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ 124: #define ktime_to_ns(kt) ((kt).tv64) 125: 126: #else /* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */ 127: 128: /* 129: * Helper macros/inlines to get the ktime_t math right in the timespec 130: * representation. The macros are sometimes ugly - their actual use is 131: * pretty okay-ish, given the circumstances. We do all this for 132: * performance reasons. The pure scalar nsec_t based code was nice and 133: * simple, but created too many 64-bit / 32-bit conversions and divisions. 134: * 135: * Be especially aware that negative values are represented in a way 136: * that the tv.sec field is negative and the tv.nsec field is greater 137: * or equal to zero but less than nanoseconds per second. This is the 138: * same representation which is used by timespecs. 139: * 140: * tv.sec < 0 and 0 >= tv.nsec < NSEC_PER_SEC 141: */ 142: 143: /* Set a ktime_t variable to a value in sec/nsec representation: */ 144: static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) 145: { 146: return (ktime_t) { .tv = { .sec = secs, .nsec = nsecs } }; 147: } 148: 149: /** 150: * ktime_sub - subtract two ktime_t variables 151: * @lhs: minuend 152: * @rhs: subtrahend 153: * 154: * Return: The remainder of the subtraction. 155: */ 156: static inline ktime_t ktime_sub(const ktime_t lhs, const ktime_t rhs) 157: { 158: ktime_t res; 159: 160: res.tv64 = lhs.tv64 - rhs.tv64; 161: if (res.tv.nsec < 0) 162: res.tv.nsec += NSEC_PER_SEC; 163: 164: return res; 165: } 166: 167: /** 168: * ktime_add - add two ktime_t variables 169: * @add1: addend1 170: * @add2: addend2 171: * 172: * Return: The sum of @add1 and @add2. 173: */ 174: static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2) 175: { 176: ktime_t res; 177: 178: res.tv64 = add1.tv64 + add2.tv64; 179: /* 180: * performance trick: the (u32) -NSEC gives 0x00000000Fxxxxxxx 181: * so we subtract NSEC_PER_SEC and add 1 to the upper 32 bit. 182: * 183: * it's equivalent to: 184: * tv.nsec -= NSEC_PER_SEC 185: * tv.sec ++; 186: */ 187: if (res.tv.nsec >= NSEC_PER_SEC) 188: res.tv64 += (u32)-NSEC_PER_SEC; 189: 190: return res; 191: } 192: 193: /** 194: * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable 195: * @kt: addend 196: * @nsec: the scalar nsec value to add 197: * 198: * Return: The sum of @kt and @nsec in ktime_t format. 199: */ 200: extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec); 201: 202: /** 203: * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable 204: * @kt: minuend 205: * @nsec: the scalar nsec value to subtract 206: * 207: * Return: The subtraction of @nsec from @kt in ktime_t format. 208: */ 209: extern ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec); 210: 211: /** 212: * timespec_to_ktime - convert a timespec to ktime_t format 213: * @ts: the timespec variable to convert 214: * 215: * Return: A ktime_t variable with the converted timespec value. 216: */ 217: static inline ktime_t timespec_to_ktime(const struct timespec ts) 218: { 219: return (ktime_t) { .tv = { .sec = (s32)ts.tv_sec, 220: .nsec = (s32)ts.tv_nsec } }; 221: } 222: 223: /** 224: * timeval_to_ktime - convert a timeval to ktime_t format 225: * @tv: the timeval variable to convert 226: * 227: * Return: A ktime_t variable with the converted timeval value. 228: */ 229: static inline ktime_t timeval_to_ktime(const struct timeval tv) 230: { 231: return (ktime_t) { .tv = { .sec = (s32)tv.tv_sec, 232: .nsec = (s32)(tv.tv_usec * 233: NSEC_PER_USEC) } }; 234: } 235: 236: /** 237: * ktime_to_timespec - convert a ktime_t variable to timespec format 238: * @kt: the ktime_t variable to convert 239: * 240: * Return: The timespec representation of the ktime value. 241: */ 242: static inline struct timespec ktime_to_timespec(const ktime_t kt) 243: { 244: return (struct timespec) { .tv_sec = (time_t) kt.tv.sec, 245: .tv_nsec = (long) kt.tv.nsec }; 246: } 247: 248: /** 249: * ktime_to_timeval - convert a ktime_t variable to timeval format 250: * @kt: the ktime_t variable to convert 251: * 252: * Return: The timeval representation of the ktime value. 253: */ 254: static inline struct timeval ktime_to_timeval(const ktime_t kt) 255: { 256: return (struct timeval) { 257: .tv_sec = (time_t) kt.tv.sec, 258: .tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) }; 259: } 260: 261: /** 262: * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds 263: * @kt: the ktime_t variable to convert 264: * 265: * Return: The scalar nanoseconds representation of @kt. 266: */ 267: static inline s64 ktime_to_ns(const ktime_t kt) 268: { 269: return (s64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec; 270: } 271: 272: #endif /* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */ 273: 274: /** 275: * ktime_equal - Compares two ktime_t variables to see if they are equal 276: * @cmp1: comparable1 277: * @cmp2: comparable2 278: * 279: * Compare two ktime_t variables. 280: * 281: * Return: 1 if equal. 282: */ 283: static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2) 284: { 285: return cmp1.tv64 == cmp2.tv64; 286: } 287: 288: /** 289: * ktime_compare - Compares two ktime_t variables for less, greater or equal 290: * @cmp1: comparable1 291: * @cmp2: comparable2 292: * 293: * Return: ... 294: * cmp1 < cmp2: return <0 295: * cmp1 == cmp2: return 0 296: * cmp1 > cmp2: return >0 297: */ 298: static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) 299: { 300: if (cmp1.tv64 < cmp2.tv64) 301: return -1; 302: if (cmp1.tv64 > cmp2.tv64) 303: return 1; 304: return 0; 305: } 306: 307: static inline s64 ktime_to_us(const ktime_t kt) 308: { 309: struct timeval tv = ktime_to_timeval(kt); 310: return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec; 311: } 312: 313: static inline s64 ktime_to_ms(const ktime_t kt) 314: { 315: struct timeval tv = ktime_to_timeval(kt); 316: return (s64) tv.tv_sec * MSEC_PER_SEC + tv.tv_usec / USEC_PER_MSEC; 317: } 318: 319: static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) 320: { 321: return ktime_to_us(ktime_sub(later, earlier)); 322: } 323: 324: static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) 325: { 326: return ktime_add_ns(kt, usec * NSEC_PER_USEC); 327: } 328: 329: static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) 330: { 331: return ktime_add_ns(kt, msec * NSEC_PER_MSEC); 332: } 333: 334: static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) 335: { 336: return ktime_sub_ns(kt, usec * NSEC_PER_USEC); 337: } 338: 339: extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); 340: 341: /** 342: * ktime_to_timespec_cond - convert a ktime_t variable to timespec 343: * format only if the variable contains data 344: * @kt: the ktime_t variable to convert 345: * @ts: the timespec variable to store the result in 346: * 347: * Return: %true if there was a successful conversion, %false if kt was 0. 348: */ 349: static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt, 350: struct timespec *ts) 351: { 352: if (kt.tv64) { 353: *ts = ktime_to_timespec(kt); 354: return true; 355: } else { 356: return false; 357: } 358: } 359: 360: /* 361: * The resolution of the clocks. The resolution value is returned in 362: * the clock_getres() system call to give application programmers an 363: * idea of the (in)accuracy of timers. Timer values are rounded up to 364: * this resolution values. 365: */ 366: #define LOW_RES_NSEC TICK_NSEC 367: #define KTIME_LOW_RES (ktime_t){ .tv64 = LOW_RES_NSEC } 368: 369: /* Get the monotonic time in timespec format: */ 370: extern void ktime_get_ts(struct timespec *ts); 371: 372: /* Get the real (wall-) time in timespec format: */ 373: #define ktime_get_real_ts(ts) getnstimeofday(ts) 374: 375: static inline ktime_t ns_to_ktime(u64 ns) 376: { 377: static const ktime_t ktime_zero = { .tv64 = 0 }; 378: 379: return ktime_add_ns(ktime_zero, ns); 380: } 381: 382: static inline ktime_t ms_to_ktime(u64 ms) 383: { 384: static const ktime_t ktime_zero = { .tv64 = 0 }; 385: 386: return ktime_add_ms(ktime_zero, ms); 387: } 388: 389: #endif 390: