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