ktime.h 6.87 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12
/*
 *  include/linux/ktime.h
 *
 *  ktime_t - nanosecond-resolution time format.
 *
 *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
 *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
 *
 *  data type definitions, declarations, prototypes and macros.
 *
 *  Started by: Thomas Gleixner and Ingo Molnar
 *
13 14 15 16 17 18
 *  Credits:
 *
 *  	Roman Zippel provided the ideas and primary code snippets of
 *  	the ktime_t union and further simplifications of the original
 *  	code.
 *
19 20 21 22 23 24 25 26 27 28 29
 *  For licencing details see kernel-base/COPYING
 */
#ifndef _LINUX_KTIME_H
#define _LINUX_KTIME_H

#include <linux/time.h>
#include <linux/jiffies.h>

/*
 * ktime_t:
 *
30
 * A single 64-bit variable is used to store the hrtimers
31 32 33 34 35 36
 * internal representation of time values in scalar nanoseconds. The
 * design plays out best on 64-bit CPUs, where most conversions are
 * NOPs and most arithmetic ktime_t operations are plain arithmetic
 * operations.
 *
 */
Andrew Morton's avatar
Andrew Morton committed
37
union ktime {
38
	s64	tv64;
Andrew Morton's avatar
Andrew Morton committed
39 40 41
};

typedef union ktime ktime_t;		/* Kill this */
42 43 44 45 46 47

/**
 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
 * @secs:	seconds to set
 * @nsecs:	nanoseconds to set
 *
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 53
	if (unlikely(secs >= KTIME_SEC_MAX))
		return (ktime_t){ .tv64 = KTIME_MAX };
54 55

	return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs };
56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72
}

/* Subtract two ktime_t variables. rem = lhs -rhs: */
#define ktime_sub(lhs, rhs) \
		({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; })

/* Add two ktime_t variables. res = lhs + rhs: */
#define ktime_add(lhs, rhs) \
		({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; })

/*
 * Add a ktime_t variable and a scalar nanosecond value.
 * res = kt + nsval:
 */
#define ktime_add_ns(kt, nsval) \
		({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; })

73 74 75 76 77 78 79
/*
 * Subtract a scalar nanosecod from a ktime_t variable
 * res = kt - nsval:
 */
#define ktime_sub_ns(kt, nsval) \
		({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; })

80
/* convert a timespec to ktime_t format: */
81 82 83 84
static inline ktime_t timespec_to_ktime(struct timespec ts)
{
	return ktime_set(ts.tv_sec, ts.tv_nsec);
}
85

86 87 88 89 90 91
/* convert a timespec64 to ktime_t format: */
static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
{
	return ktime_set(ts.tv_sec, ts.tv_nsec);
}

92
/* convert a timeval to ktime_t format: */
93 94 95 96
static inline ktime_t timeval_to_ktime(struct timeval tv)
{
	return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
}
97 98 99 100

/* Map the ktime_t to timespec conversion to ns_to_timespec function */
#define ktime_to_timespec(kt)		ns_to_timespec((kt).tv64)

101 102 103
/* Map the ktime_t to timespec conversion to ns_to_timespec function */
#define ktime_to_timespec64(kt)		ns_to_timespec64((kt).tv64)

104 105 106 107 108 109 110
/* Map the ktime_t to timeval conversion to ns_to_timeval function */
#define ktime_to_timeval(kt)		ns_to_timeval((kt).tv64)

/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
#define ktime_to_ns(kt)			((kt).tv64)


111 112 113 114 115
/**
 * ktime_equal - Compares two ktime_t variables to see if they are equal
 * @cmp1:	comparable1
 * @cmp2:	comparable2
 *
116 117 118
 * Compare two ktime_t variables.
 *
 * Return: 1 if equal.
119 120 121 122 123 124
 */
static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2)
{
	return cmp1.tv64 == cmp2.tv64;
}

125 126 127 128 129
/**
 * ktime_compare - Compares two ktime_t variables for less, greater or equal
 * @cmp1:	comparable1
 * @cmp2:	comparable2
 *
130
 * Return: ...
131 132 133 134 135 136 137 138 139 140 141 142 143
 *   cmp1  < cmp2: return <0
 *   cmp1 == cmp2: return 0
 *   cmp1  > cmp2: return >0
 */
static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
{
	if (cmp1.tv64 < cmp2.tv64)
		return -1;
	if (cmp1.tv64 > cmp2.tv64)
		return 1;
	return 0;
}

144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
/**
 * ktime_after - Compare if a ktime_t value is bigger than another one.
 * @cmp1:	comparable1
 * @cmp2:	comparable2
 *
 * Return: true if cmp1 happened after cmp2.
 */
static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
{
	return ktime_compare(cmp1, cmp2) > 0;
}

/**
 * ktime_before - Compare if a ktime_t value is smaller than another one.
 * @cmp1:	comparable1
 * @cmp2:	comparable2
 *
 * Return: true if cmp1 happened before cmp2.
 */
static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
{
	return ktime_compare(cmp1, cmp2) < 0;
}

168 169 170 171 172 173
#if BITS_PER_LONG < 64
extern u64 ktime_divns(const ktime_t kt, s64 div);
#else /* BITS_PER_LONG < 64 */
# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
#endif

174 175
static inline s64 ktime_to_us(const ktime_t kt)
{
176
	return ktime_divns(kt, NSEC_PER_USEC);
177 178
}

179 180
static inline s64 ktime_to_ms(const ktime_t kt)
{
181
	return ktime_divns(kt, NSEC_PER_MSEC);
182 183
}

184 185 186 187 188
static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
{
       return ktime_to_us(ktime_sub(later, earlier));
}

189 190
static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
{
191
	return ktime_add_ns(kt, usec * NSEC_PER_USEC);
192 193
}

194 195 196 197 198
static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec)
{
	return ktime_add_ns(kt, msec * NSEC_PER_MSEC);
}

199 200
static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
{
201
	return ktime_sub_ns(kt, usec * NSEC_PER_USEC);
202 203
}

204 205
extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);

206 207 208 209 210 211
/**
 * ktime_to_timespec_cond - convert a ktime_t variable to timespec
 *			    format only if the variable contains data
 * @kt:		the ktime_t variable to convert
 * @ts:		the timespec variable to store the result in
 *
212
 * Return: %true if there was a successful conversion, %false if kt was 0.
213
 */
214 215
static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt,
						       struct timespec *ts)
216 217 218 219 220 221 222 223 224
{
	if (kt.tv64) {
		*ts = ktime_to_timespec(kt);
		return true;
	} else {
		return false;
	}
}

225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243
/**
 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
 *			    format only if the variable contains data
 * @kt:		the ktime_t variable to convert
 * @ts:		the timespec variable to store the result in
 *
 * Return: %true if there was a successful conversion, %false if kt was 0.
 */
static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
						       struct timespec64 *ts)
{
	if (kt.tv64) {
		*ts = ktime_to_timespec64(kt);
		return true;
	} else {
		return false;
	}
}

244 245 246 247 248 249
/*
 * The resolution of the clocks. The resolution value is returned in
 * the clock_getres() system call to give application programmers an
 * idea of the (in)accuracy of timers. Timer values are rounded up to
 * this resolution values.
 */
250 251
#define LOW_RES_NSEC		TICK_NSEC
#define KTIME_LOW_RES		(ktime_t){ .tv64 = LOW_RES_NSEC }
252 253 254 255 256 257 258

/* Get the monotonic time in timespec format: */
extern void ktime_get_ts(struct timespec *ts);

/* Get the real (wall-) time in timespec format: */
#define ktime_get_real_ts(ts)	getnstimeofday(ts)

Ingo Molnar's avatar
Ingo Molnar committed
259 260 261
static inline ktime_t ns_to_ktime(u64 ns)
{
	static const ktime_t ktime_zero = { .tv64 = 0 };
262

Ingo Molnar's avatar
Ingo Molnar committed
263 264 265
	return ktime_add_ns(ktime_zero, ns);
}

266 267 268 269 270 271 272
static inline ktime_t ms_to_ktime(u64 ms)
{
	static const ktime_t ktime_zero = { .tv64 = 0 };

	return ktime_add_ms(ktime_zero, ms);
}

273
#endif