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/clockchips.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/of_clk.h>
 20#include <linux/profile.h>
 21#include <linux/sched.h>
 22#include <linux/sched_clock.h>
 23#include <linux/smp.h>
 24#include <linux/time.h>
 25#include <linux/timex.h>
 26#include <linux/timer.h>
 27
 28#include <asm/mach/arch.h>
 29#include <asm/mach/time.h>
 30#include <asm/stacktrace.h>
 31#include <asm/thread_info.h>
 32
 33#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
 34    defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
 35/* this needs a better home */
 36DEFINE_SPINLOCK(rtc_lock);
 37EXPORT_SYMBOL(rtc_lock);
 38#endif	/* pc-style 'CMOS' RTC support */
 39
 40/* change this if you have some constant time drift */
 41#define USECS_PER_JIFFY	(1000000/HZ)
 42
 43#ifdef CONFIG_SMP
 44unsigned long profile_pc(struct pt_regs *regs)
 45{
 46	struct stackframe frame;
 47
 48	if (!in_lock_functions(regs->ARM_pc))
 49		return regs->ARM_pc;
 50
 51	arm_get_current_stackframe(regs, &frame);
 52	do {
 53		int ret = unwind_frame(&frame);
 54		if (ret < 0)
 55			return 0;
 56	} while (in_lock_functions(frame.pc));
 57
 58	return frame.pc;
 59}
 60EXPORT_SYMBOL(profile_pc);
 61#endif
 62
 63#ifndef CONFIG_GENERIC_CLOCKEVENTS
 64/*
 65 * Kernel system timer support.
 66 */
 67void timer_tick(void)
 68{
 69	profile_tick(CPU_PROFILING);
 70	xtime_update(1);
 71#ifndef CONFIG_SMP
 72	update_process_times(user_mode(get_irq_regs()));
 73#endif
 74}
 75#endif
 76
 77static void dummy_clock_access(struct timespec64 *ts)
 78{
 79	ts->tv_sec = 0;
 80	ts->tv_nsec = 0;
 81}
 82
 83static clock_access_fn __read_persistent_clock = dummy_clock_access;
 84
 85void read_persistent_clock64(struct timespec64 *ts)
 86{
 87	__read_persistent_clock(ts);
 88}
 89
 90int __init register_persistent_clock(clock_access_fn read_persistent)
 91{
 92	/* Only allow the clockaccess functions to be registered once */
 93	if (__read_persistent_clock == dummy_clock_access) {
 94		if (read_persistent)
 95			__read_persistent_clock = read_persistent;
 96		return 0;
 97	}
 98
 99	return -EINVAL;
100}
101
102void __init time_init(void)
103{
104	if (machine_desc->init_time) {
105		machine_desc->init_time();
106	} else {
107#ifdef CONFIG_COMMON_CLK
108		of_clk_init(NULL);
109#endif
110		timer_probe();
111		tick_setup_hrtimer_broadcast();
112	}
113}

 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/clockchips.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/of_clk.h>
20#include <linux/profile.h>
21#include <linux/sched.h>
22#include <linux/sched_clock.h>
23#include <linux/smp.h>
24#include <linux/time.h>
25#include <linux/timex.h>
26#include <linux/timer.h>
27
28#include <asm/mach/arch.h>
29#include <asm/mach/time.h>
30#include <asm/stacktrace.h>
31#include <asm/thread_info.h>
32
33#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
34    defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
35/* this needs a better home */
36DEFINE_SPINLOCK(rtc_lock);
37EXPORT_SYMBOL(rtc_lock);
38#endif	/* pc-style 'CMOS' RTC support */
39
40/* change this if you have some constant time drift */
41#define USECS_PER_JIFFY	(1000000/HZ)
42
43#ifdef CONFIG_SMP
44unsigned long profile_pc(struct pt_regs *regs)
45{
46	struct stackframe frame;
47
48	if (!in_lock_functions(regs->ARM_pc))
49		return regs->ARM_pc;
50
51	arm_get_current_stackframe(regs, &frame);
52	do {
53		int ret = unwind_frame(&frame);
54		if (ret < 0)
55			return 0;
56	} while (in_lock_functions(frame.pc));
57
58	return frame.pc;
59}
60EXPORT_SYMBOL(profile_pc);
61#endif
62
 
 
 
 
 
 
 
 
 
 
 
 
 
 
63static void dummy_clock_access(struct timespec64 *ts)
64{
65	ts->tv_sec = 0;
66	ts->tv_nsec = 0;
67}
68
69static clock_access_fn __read_persistent_clock = dummy_clock_access;
70
71void read_persistent_clock64(struct timespec64 *ts)
72{
73	__read_persistent_clock(ts);
74}
75
76int __init register_persistent_clock(clock_access_fn read_persistent)
77{
78	/* Only allow the clockaccess functions to be registered once */
79	if (__read_persistent_clock == dummy_clock_access) {
80		if (read_persistent)
81			__read_persistent_clock = read_persistent;
82		return 0;
83	}
84
85	return -EINVAL;
86}
87
88void __init time_init(void)
89{
90	if (machine_desc->init_time) {
91		machine_desc->init_time();
92	} else {
93#ifdef CONFIG_COMMON_CLK
94		of_clk_init(NULL);
95#endif
96		timer_probe();
97		tick_setup_hrtimer_broadcast();
98	}
99}