1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 1991,1992,1995 Linus Torvalds
4 * Copyright (c) 1994 Alan Modra
5 * Copyright (c) 1995 Markus Kuhn
6 * Copyright (c) 1996 Ingo Molnar
7 * Copyright (c) 1998 Andrea Arcangeli
8 * Copyright (c) 2002,2006 Vojtech Pavlik
9 * Copyright (c) 2003 Andi Kleen
10 *
11 */
12
13 #include <linux/clocksource.h>
14 #include <linux/clockchips.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/i8253.h>
18 #include <linux/time.h>
19 #include <linux/export.h>
20
21 #include <asm/vsyscall.h>
22 #include <asm/x86_init.h>
23 #include <asm/i8259.h>
24 #include <asm/timer.h>
25 #include <asm/hpet.h>
26 #include <asm/time.h>
27
28 #ifdef CONFIG_X86_64
29 __visible volatile unsigned long jiffies __cacheline_aligned_in_smp = INITIAL_JIFFIES;
30 #endif
31
profile_pc(struct pt_regs * regs)32 unsigned long profile_pc(struct pt_regs *regs)
33 {
34 unsigned long pc = instruction_pointer(regs);
35
36 if (!user_mode(regs) && in_lock_functions(pc)) {
37 #ifdef CONFIG_FRAME_POINTER
38 return *(unsigned long *)(regs->bp + sizeof(long));
39 #else
40 unsigned long *sp = (unsigned long *)regs->sp;
41 /*
42 * Return address is either directly at stack pointer
43 * or above a saved flags. Eflags has bits 22-31 zero,
44 * kernel addresses don't.
45 */
46 if (sp[0] >> 22)
47 return sp[0];
48 if (sp[1] >> 22)
49 return sp[1];
50 #endif
51 }
52 return pc;
53 }
54 EXPORT_SYMBOL(profile_pc);
55
56 /*
57 * Default timer interrupt handler for PIT/HPET
58 */
timer_interrupt(int irq,void * dev_id)59 static irqreturn_t timer_interrupt(int irq, void *dev_id)
60 {
61 global_clock_event->event_handler(global_clock_event);
62 return IRQ_HANDLED;
63 }
64
65 static struct irqaction irq0 = {
66 .handler = timer_interrupt,
67 .flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
68 .name = "timer"
69 };
70
setup_default_timer_irq(void)71 static void __init setup_default_timer_irq(void)
72 {
73 /*
74 * Unconditionally register the legacy timer; even without legacy
75 * PIC/PIT we need this for the HPET0 in legacy replacement mode.
76 */
77 if (setup_irq(0, &irq0))
78 pr_info("Failed to register legacy timer interrupt\n");
79 }
80
81 /* Default timer init function */
hpet_time_init(void)82 void __init hpet_time_init(void)
83 {
84 if (!hpet_enable()) {
85 if (!pit_timer_init())
86 return;
87 }
88
89 setup_default_timer_irq();
90 }
91
x86_late_time_init(void)92 static __init void x86_late_time_init(void)
93 {
94 x86_init.timers.timer_init();
95 /*
96 * After PIT/HPET timers init, select and setup
97 * the final interrupt mode for delivering IRQs.
98 */
99 x86_init.irqs.intr_mode_init();
100 tsc_init();
101 }
102
103 /*
104 * Initialize TSC and delay the periodic timer init to
105 * late x86_late_time_init() so ioremap works.
106 */
time_init(void)107 void __init time_init(void)
108 {
109 late_time_init = x86_late_time_init;
110 }
111
112 /*
113 * Sanity check the vdso related archdata content.
114 */
clocksource_arch_init(struct clocksource * cs)115 void clocksource_arch_init(struct clocksource *cs)
116 {
117 if (cs->archdata.vclock_mode == VCLOCK_NONE)
118 return;
119
120 if (cs->archdata.vclock_mode > VCLOCK_MAX) {
121 pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
122 cs->name, cs->archdata.vclock_mode);
123 cs->archdata.vclock_mode = VCLOCK_NONE;
124 }
125
126 if (cs->mask != CLOCKSOURCE_MASK(64)) {
127 pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
128 cs->name, cs->mask);
129 cs->archdata.vclock_mode = VCLOCK_NONE;
130 }
131 }
132