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authorThomas Gleixner <tglx@linutronix.de>2014-09-14 09:34:38 -0400
committerThomas Gleixner <tglx@linutronix.de>2014-09-14 09:35:36 -0400
commitdb985cbd67c45f875ef43cb5febfaa8cbd203c27 (patch)
tree63542d05b1c0f730ec1ad5f915dc4eb3c015e616 /include/linux/ktime.h
parentc6f1224573c3b609bd8073b39f496637a16cc06f (diff)
parent468a903c0e5147e3f93187f0b808a3ef957fd00e (diff)
Merge tag 'irqchip-core-3.18' of git://git.infradead.org/users/jcooper/linux into irq/core
irqchip core changes for v3.18 - renesas: suspend to RAM, runtime PM, cleanups and DT binding docs - keystone: add new driver - hip04: add Hisilicon HiP04 driver (without touching irq-gic.c) - gic: Use defines instead of magic number, preserve v2 bybass bits - handle_domain_irq: common low level interrupt entry handler
Diffstat (limited to 'include/linux/ktime.h')
-rw-r--r--include/linux/ktime.h228
1 files changed, 42 insertions, 186 deletions
diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index de9e46e6bcc9..c9d645ad98ff 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -27,43 +27,19 @@
27/* 27/*
28 * ktime_t: 28 * ktime_t:
29 * 29 *
30 * On 64-bit CPUs a single 64-bit variable is used to store the hrtimers 30 * A single 64-bit variable is used to store the hrtimers
31 * internal representation of time values in scalar nanoseconds. The 31 * internal representation of time values in scalar nanoseconds. The
32 * design plays out best on 64-bit CPUs, where most conversions are 32 * design plays out best on 64-bit CPUs, where most conversions are
33 * NOPs and most arithmetic ktime_t operations are plain arithmetic 33 * NOPs and most arithmetic ktime_t operations are plain arithmetic
34 * operations. 34 * operations.
35 * 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 */ 36 */
46union ktime { 37union ktime {
47 s64 tv64; 38 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}; 39};
58 40
59typedef union ktime ktime_t; /* Kill this */ 41typedef union ktime ktime_t; /* Kill this */
60 42
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/** 43/**
68 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value 44 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
69 * @secs: seconds to set 45 * @secs: seconds to set
@@ -71,13 +47,12 @@ typedef union ktime ktime_t; /* Kill this */
71 * 47 *
72 * Return: The ktime_t representation of the value. 48 * Return: The ktime_t representation of the value.
73 */ 49 */
74static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) 50static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
75{ 51{
76#if (BITS_PER_LONG == 64)
77 if (unlikely(secs >= KTIME_SEC_MAX)) 52 if (unlikely(secs >= KTIME_SEC_MAX))
78 return (ktime_t){ .tv64 = KTIME_MAX }; 53 return (ktime_t){ .tv64 = KTIME_MAX };
79#endif 54
80 return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs }; 55 return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs };
81} 56}
82 57
83/* Subtract two ktime_t variables. rem = lhs -rhs: */ 58/* Subtract two ktime_t variables. rem = lhs -rhs: */
@@ -108,6 +83,12 @@ static inline ktime_t timespec_to_ktime(struct timespec ts)
108 return ktime_set(ts.tv_sec, ts.tv_nsec); 83 return ktime_set(ts.tv_sec, ts.tv_nsec);
109} 84}
110 85
86/* convert a timespec64 to ktime_t format: */
87static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
88{
89 return ktime_set(ts.tv_sec, ts.tv_nsec);
90}
91
111/* convert a timeval to ktime_t format: */ 92/* convert a timeval to ktime_t format: */
112static inline ktime_t timeval_to_ktime(struct timeval tv) 93static inline ktime_t timeval_to_ktime(struct timeval tv)
113{ 94{
@@ -117,159 +98,15 @@ static inline ktime_t timeval_to_ktime(struct timeval tv)
117/* Map the ktime_t to timespec conversion to ns_to_timespec function */ 98/* Map the ktime_t to timespec conversion to ns_to_timespec function */
118#define ktime_to_timespec(kt) ns_to_timespec((kt).tv64) 99#define ktime_to_timespec(kt) ns_to_timespec((kt).tv64)
119 100
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
120/* Map the ktime_t to timeval conversion to ns_to_timeval function */ 104/* Map the ktime_t to timeval conversion to ns_to_timeval function */
121#define ktime_to_timeval(kt) ns_to_timeval((kt).tv64) 105#define ktime_to_timeval(kt) ns_to_timeval((kt).tv64)
122 106
123/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ 107/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
124#define ktime_to_ns(kt) ((kt).tv64) 108#define ktime_to_ns(kt) ((kt).tv64)
125 109
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: */
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
151 * @lhs: minuend
152 * @rhs: subtrahend
153 *
154 * Return: The remainder of the subtraction.
155 */
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
169 * @add1: addend1
170 * @add2: addend2
171 *
172 * Return: The sum of @add1 and @add2.
173 */
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
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 */
200extern 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 */
209extern 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.