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1/*
2 * linux/arch/arm/kernel/time.c
3 *
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
5 * Modifications for ARM (C) 1994-2001 Russell King
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This file contains the ARM-specific time handling details:
12 * reading the RTC at bootup, etc...
13 */
14#include <linux/clk-provider.h>
15#include <linux/clocksource.h>
16#include <linux/errno.h>
17#include <linux/export.h>
18#include <linux/init.h>
19#include <linux/interrupt.h>
20#include <linux/irq.h>
21#include <linux/kernel.h>
22#include <linux/profile.h>
23#include <linux/sched.h>
24#include <linux/sched_clock.h>
25#include <linux/smp.h>
26#include <linux/time.h>
27#include <linux/timex.h>
28#include <linux/timer.h>
29
30#include <asm/mach/arch.h>
31#include <asm/mach/time.h>
32#include <asm/stacktrace.h>
33#include <asm/thread_info.h>
34
35#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
36 defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
37/* this needs a better home */
38DEFINE_SPINLOCK(rtc_lock);
39EXPORT_SYMBOL(rtc_lock);
40#endif /* pc-style 'CMOS' RTC support */
41
42/* change this if you have some constant time drift */
43#define USECS_PER_JIFFY (1000000/HZ)
44
45#ifdef CONFIG_SMP
46unsigned long profile_pc(struct pt_regs *regs)
47{
48 struct stackframe frame;
49
50 if (!in_lock_functions(regs->ARM_pc))
51 return regs->ARM_pc;
52
53 arm_get_current_stackframe(regs, &frame);
54 do {
55 int ret = unwind_frame(&frame);
56 if (ret < 0)
57 return 0;
58 } while (in_lock_functions(frame.pc));
59
60 return frame.pc;
61}
62EXPORT_SYMBOL(profile_pc);
63#endif
64
65#ifndef CONFIG_GENERIC_CLOCKEVENTS
66/*
67 * Kernel system timer support.
68 */
69void timer_tick(void)
70{
71 profile_tick(CPU_PROFILING);
72 xtime_update(1);
73#ifndef CONFIG_SMP
74 update_process_times(user_mode(get_irq_regs()));
75#endif
76}
77#endif
78
79static void dummy_clock_access(struct timespec64 *ts)
80{
81 ts->tv_sec = 0;
82 ts->tv_nsec = 0;
83}
84
85static clock_access_fn __read_persistent_clock = dummy_clock_access;
86static clock_access_fn __read_boot_clock = dummy_clock_access;;
87
88void read_persistent_clock64(struct timespec64 *ts)
89{
90 __read_persistent_clock(ts);
91}
92
93void read_boot_clock64(struct timespec64 *ts)
94{
95 __read_boot_clock(ts);
96}
97
98int __init register_persistent_clock(clock_access_fn read_boot,
99 clock_access_fn read_persistent)
100{
101 /* Only allow the clockaccess functions to be registered once */
102 if (__read_persistent_clock == dummy_clock_access &&
103 __read_boot_clock == dummy_clock_access) {
104 if (read_boot)
105 __read_boot_clock = read_boot;
106 if (read_persistent)
107 __read_persistent_clock = read_persistent;
108
109 return 0;
110 }
111
112 return -EINVAL;
113}
114
115void __init time_init(void)
116{
117 if (machine_desc->init_time) {
118 machine_desc->init_time();
119 } else {
120#ifdef CONFIG_COMMON_CLK
121 of_clk_init(NULL);
122#endif
123 clocksource_probe();
124 }
125}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/arm/kernel/time.c
4 *
5 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
6 * Modifications for ARM (C) 1994-2001 Russell King
7 *
8 * This file contains the ARM-specific time handling details:
9 * reading the RTC at bootup, etc...
10 */
11#include <linux/clk-provider.h>
12#include <linux/clocksource.h>
13#include <linux/errno.h>
14#include <linux/export.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/kernel.h>
19#include <linux/profile.h>
20#include <linux/sched.h>
21#include <linux/sched_clock.h>
22#include <linux/smp.h>
23#include <linux/time.h>
24#include <linux/timex.h>
25#include <linux/timer.h>
26
27#include <asm/mach/arch.h>
28#include <asm/mach/time.h>
29#include <asm/stacktrace.h>
30#include <asm/thread_info.h>
31
32#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
33 defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
34/* this needs a better home */
35DEFINE_SPINLOCK(rtc_lock);
36EXPORT_SYMBOL(rtc_lock);
37#endif /* pc-style 'CMOS' RTC support */
38
39/* change this if you have some constant time drift */
40#define USECS_PER_JIFFY (1000000/HZ)
41
42#ifdef CONFIG_SMP
43unsigned long profile_pc(struct pt_regs *regs)
44{
45 struct stackframe frame;
46
47 if (!in_lock_functions(regs->ARM_pc))
48 return regs->ARM_pc;
49
50 arm_get_current_stackframe(regs, &frame);
51 do {
52 int ret = unwind_frame(&frame);
53 if (ret < 0)
54 return 0;
55 } while (in_lock_functions(frame.pc));
56
57 return frame.pc;
58}
59EXPORT_SYMBOL(profile_pc);
60#endif
61
62#ifndef CONFIG_GENERIC_CLOCKEVENTS
63/*
64 * Kernel system timer support.
65 */
66void timer_tick(void)
67{
68 profile_tick(CPU_PROFILING);
69 xtime_update(1);
70#ifndef CONFIG_SMP
71 update_process_times(user_mode(get_irq_regs()));
72#endif
73}
74#endif
75
76static void dummy_clock_access(struct timespec64 *ts)
77{
78 ts->tv_sec = 0;
79 ts->tv_nsec = 0;
80}
81
82static clock_access_fn __read_persistent_clock = dummy_clock_access;
83
84void read_persistent_clock64(struct timespec64 *ts)
85{
86 __read_persistent_clock(ts);
87}
88
89int __init register_persistent_clock(clock_access_fn read_persistent)
90{
91 /* Only allow the clockaccess functions to be registered once */
92 if (__read_persistent_clock == dummy_clock_access) {
93 if (read_persistent)
94 __read_persistent_clock = read_persistent;
95 return 0;
96 }
97
98 return -EINVAL;
99}
100
101void __init time_init(void)
102{
103 if (machine_desc->init_time) {
104 machine_desc->init_time();
105 } else {
106#ifdef CONFIG_COMMON_CLK
107 of_clk_init(NULL);
108#endif
109 timer_probe();
110 }
111}