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Thomas Gleixner97fc79f2006-01-09 20:52:31 -08001/*
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 *
Thomas Gleixner66188fa2006-02-01 03:05:13 -080013 * 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 *
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080019 * 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
Lucas De Marchi25985ed2011-03-30 22:57:33 -030038 * endian-aware order of the tv struct members is chosen to allow
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080039 * 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 */
Andrew Mortonf34c5062007-05-09 02:34:59 -070046union ktime {
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080047 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
Andrew Mortonf34c5062007-05-09 02:34:59 -070057};
58
59typedef union ktime ktime_t; /* Kill this */
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080060
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080061/*
62 * ktime_t definitions when using the 64-bit scalar representation:
63 */
64
65#if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)
66
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080067/**
68 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080069 * @secs: seconds to set
70 * @nsecs: nanoseconds to set
71 *
72 * Return the ktime_t representation of the value
73 */
74static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)
75{
Thomas Gleixner96dd7422006-09-06 00:03:42 -070076#if (BITS_PER_LONG == 64)
77 if (unlikely(secs >= KTIME_SEC_MAX))
78 return (ktime_t){ .tv64 = KTIME_MAX };
79#endif
Thomas Gleixner97fc79f2006-01-09 20:52:31 -080080 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
Arnaldo Carvalho de Meloa2723782007-08-19 17:16:05 -070098/*
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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800105/* convert a timespec to ktime_t format: */
Roman Zippelb2ee9db2006-02-15 15:17:40 -0800106static inline ktime_t timespec_to_ktime(struct timespec ts)
107{
108 return ktime_set(ts.tv_sec, ts.tv_nsec);
109}
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800110
111/* convert a timeval to ktime_t format: */
Roman Zippelb2ee9db2006-02-15 15:17:40 -0800112static inline ktime_t timeval_to_ktime(struct timeval tv)
113{
114 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
115}
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800116
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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800123/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
124#define ktime_to_ns(kt) ((kt).tv64)
125
Chuck Leverf56916b2010-05-07 13:34:37 -0400126#else /* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800127
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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800143/* Set a ktime_t variable to a value in sec/nsec representation: */
144static 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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800151 * @lhs: minuend
152 * @rhs: subtrahend
153 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300154 * Returns the remainder of the subtraction
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800155 */
156static 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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800169 * @add1: addend1
170 * @add2: addend2
171 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800172 * Returns the sum of @add1 and @add2.
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800173 */
174static 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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800195 * @kt: addend
196 * @nsec: the scalar nsec value to add
197 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800198 * Returns the sum of @kt and @nsec in ktime_t format
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800199 */
200extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec);
201
202/**
Arnaldo Carvalho de Meloa2723782007-08-19 17:16:05 -0700203 * 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 * Returns the subtraction of @nsec from @kt in ktime_t format
208 */
209extern ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec);
210
211/**
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800212 * timespec_to_ktime - convert a timespec to ktime_t format
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800213 * @ts: the timespec variable to convert
214 *
215 * Returns a ktime_t variable with the converted timespec value
216 */
217static 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
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800225 * @tv: the timeval variable to convert
226 *
227 * Returns a ktime_t variable with the converted timeval value
228 */
229static 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 * 1000 } };
233}
234
235/**
236 * ktime_to_timespec - convert a ktime_t variable to timespec format
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800237 * @kt: the ktime_t variable to convert
238 *
239 * Returns the timespec representation of the ktime value
240 */
241static inline struct timespec ktime_to_timespec(const ktime_t kt)
242{
243 return (struct timespec) { .tv_sec = (time_t) kt.tv.sec,
244 .tv_nsec = (long) kt.tv.nsec };
245}
246
247/**
248 * ktime_to_timeval - convert a ktime_t variable to timeval format
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800249 * @kt: the ktime_t variable to convert
250 *
251 * Returns the timeval representation of the ktime value
252 */
253static inline struct timeval ktime_to_timeval(const ktime_t kt)
254{
255 return (struct timeval) {
256 .tv_sec = (time_t) kt.tv.sec,
257 .tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) };
258}
259
260/**
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800261 * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds
262 * @kt: the ktime_t variable to convert
263 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800264 * Returns the scalar nanoseconds representation of @kt
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800265 */
Thomas Gleixnercfd18932006-12-06 20:37:38 -0800266static inline s64 ktime_to_ns(const ktime_t kt)
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800267{
Thomas Gleixnercfd18932006-12-06 20:37:38 -0800268 return (s64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec;
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800269}
270
Chuck Leverf56916b2010-05-07 13:34:37 -0400271#endif /* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800272
Ilpo Järvinenb9ce2042007-06-15 15:08:43 -0700273/**
274 * ktime_equal - Compares two ktime_t variables to see if they are equal
275 * @cmp1: comparable1
276 * @cmp2: comparable2
277 *
278 * Compare two ktime_t variables, returns 1 if equal
279 */
280static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2)
281{
282 return cmp1.tv64 == cmp2.tv64;
283}
284
YOSHIFUJI Hideaki84299b32007-04-24 16:21:38 -0700285static inline s64 ktime_to_us(const ktime_t kt)
286{
287 struct timeval tv = ktime_to_timeval(kt);
288 return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
289}
290
Chuck Leverf56916b2010-05-07 13:34:37 -0400291static inline s64 ktime_to_ms(const ktime_t kt)
292{
293 struct timeval tv = ktime_to_timeval(kt);
294 return (s64) tv.tv_sec * MSEC_PER_SEC + tv.tv_usec / USEC_PER_MSEC;
295}
296
Gerrit Renkerf1c91da2007-06-16 12:38:51 -0300297static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
298{
299 return ktime_to_us(ktime_sub(later, earlier));
300}
301
Arnaldo Carvalho de Melo1e180f72007-06-16 12:39:38 -0300302static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
303{
304 return ktime_add_ns(kt, usec * 1000);
305}
306
Arnaldo Carvalho de Meloa2723782007-08-19 17:16:05 -0700307static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
308{
309 return ktime_sub_ns(kt, usec * 1000);
310}
311
Thomas Gleixner5a7780e2008-02-13 09:20:43 +0100312extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
313
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800314/*
315 * The resolution of the clocks. The resolution value is returned in
316 * the clock_getres() system call to give application programmers an
317 * idea of the (in)accuracy of timers. Timer values are rounded up to
318 * this resolution values.
319 */
Tony Breeds151db1f2008-02-08 09:24:52 +1100320#define LOW_RES_NSEC TICK_NSEC
321#define KTIME_LOW_RES (ktime_t){ .tv64 = LOW_RES_NSEC }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800322
323/* Get the monotonic time in timespec format: */
324extern void ktime_get_ts(struct timespec *ts);
325
326/* Get the real (wall-) time in timespec format: */
327#define ktime_get_real_ts(ts) getnstimeofday(ts)
328
Ingo Molnar57d3da22008-02-27 14:05:10 +0100329static inline ktime_t ns_to_ktime(u64 ns)
330{
331 static const ktime_t ktime_zero = { .tv64 = 0 };
332 return ktime_add_ns(ktime_zero, ns);
333}
334
Thomas Gleixner97fc79f2006-01-09 20:52:31 -0800335#endif