xref: /OK3568_Linux_fs/kernel/include/linux/sched/clock.h (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _LINUX_SCHED_CLOCK_H
3*4882a593Smuzhiyun #define _LINUX_SCHED_CLOCK_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <linux/smp.h>
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun /*
8*4882a593Smuzhiyun  * Do not use outside of architecture code which knows its limitations.
9*4882a593Smuzhiyun  *
10*4882a593Smuzhiyun  * sched_clock() has no promise of monotonicity or bounded drift between
11*4882a593Smuzhiyun  * CPUs, use (which you should not) requires disabling IRQs.
12*4882a593Smuzhiyun  *
13*4882a593Smuzhiyun  * Please use one of the three interfaces below.
14*4882a593Smuzhiyun  */
15*4882a593Smuzhiyun extern unsigned long long notrace sched_clock(void);
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun /*
18*4882a593Smuzhiyun  * See the comment in kernel/sched/clock.c
19*4882a593Smuzhiyun  */
20*4882a593Smuzhiyun extern u64 running_clock(void);
21*4882a593Smuzhiyun extern u64 sched_clock_cpu(int cpu);
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun extern void sched_clock_init(void);
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
sched_clock_tick(void)27*4882a593Smuzhiyun static inline void sched_clock_tick(void)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun }
30*4882a593Smuzhiyun 
clear_sched_clock_stable(void)31*4882a593Smuzhiyun static inline void clear_sched_clock_stable(void)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun 
sched_clock_idle_sleep_event(void)35*4882a593Smuzhiyun static inline void sched_clock_idle_sleep_event(void)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun 
sched_clock_idle_wakeup_event(void)39*4882a593Smuzhiyun static inline void sched_clock_idle_wakeup_event(void)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun 
cpu_clock(int cpu)43*4882a593Smuzhiyun static inline u64 cpu_clock(int cpu)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun 	return sched_clock();
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun 
local_clock(void)48*4882a593Smuzhiyun static inline u64 local_clock(void)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun 	return sched_clock();
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun #else
53*4882a593Smuzhiyun extern int sched_clock_stable(void);
54*4882a593Smuzhiyun extern void clear_sched_clock_stable(void);
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun /*
57*4882a593Smuzhiyun  * When sched_clock_stable(), __sched_clock_offset provides the offset
58*4882a593Smuzhiyun  * between local_clock() and sched_clock().
59*4882a593Smuzhiyun  */
60*4882a593Smuzhiyun extern u64 __sched_clock_offset;
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun extern void sched_clock_tick(void);
63*4882a593Smuzhiyun extern void sched_clock_tick_stable(void);
64*4882a593Smuzhiyun extern void sched_clock_idle_sleep_event(void);
65*4882a593Smuzhiyun extern void sched_clock_idle_wakeup_event(void);
66*4882a593Smuzhiyun 
67*4882a593Smuzhiyun /*
68*4882a593Smuzhiyun  * As outlined in clock.c, provides a fast, high resolution, nanosecond
69*4882a593Smuzhiyun  * time source that is monotonic per cpu argument and has bounded drift
70*4882a593Smuzhiyun  * between cpus.
71*4882a593Smuzhiyun  *
72*4882a593Smuzhiyun  * ######################### BIG FAT WARNING ##########################
73*4882a593Smuzhiyun  * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
74*4882a593Smuzhiyun  * # go backwards !!                                                  #
75*4882a593Smuzhiyun  * ####################################################################
76*4882a593Smuzhiyun  */
cpu_clock(int cpu)77*4882a593Smuzhiyun static inline u64 cpu_clock(int cpu)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun 	return sched_clock_cpu(cpu);
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun 
local_clock(void)82*4882a593Smuzhiyun static inline u64 local_clock(void)
83*4882a593Smuzhiyun {
84*4882a593Smuzhiyun 	return sched_clock_cpu(raw_smp_processor_id());
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun #endif
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun #ifdef CONFIG_IRQ_TIME_ACCOUNTING
89*4882a593Smuzhiyun /*
90*4882a593Smuzhiyun  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
91*4882a593Smuzhiyun  * The reason for this explicit opt-in is not to have perf penalty with
92*4882a593Smuzhiyun  * slow sched_clocks.
93*4882a593Smuzhiyun  */
94*4882a593Smuzhiyun extern void enable_sched_clock_irqtime(void);
95*4882a593Smuzhiyun extern void disable_sched_clock_irqtime(void);
96*4882a593Smuzhiyun #else
enable_sched_clock_irqtime(void)97*4882a593Smuzhiyun static inline void enable_sched_clock_irqtime(void) {}
disable_sched_clock_irqtime(void)98*4882a593Smuzhiyun static inline void disable_sched_clock_irqtime(void) {}
99*4882a593Smuzhiyun #endif
100*4882a593Smuzhiyun 
101*4882a593Smuzhiyun #endif /* _LINUX_SCHED_CLOCK_H */
102