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 unsigned long profile_pc(struct pt_regs *regs)
29 {
30 return instruction_pointer(regs);
31 }
32 EXPORT_SYMBOL(profile_pc);
33
34 /*
35 * Default timer interrupt handler for PIT/HPET
36 */
37 static irqreturn_t timer_interrupt(int irq, void *dev_id)
38 {
39 global_clock_event->event_handler(global_clock_event);
40 return IRQ_HANDLED;
41 }
42
43 static void __init setup_default_timer_irq(void)
44 {
45 unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER;
46
47 /*
48 * Unconditionally register the legacy timer interrupt; even
49 * without legacy PIC/PIT we need this for the HPET0 in legacy
50 * replacement mode.
51 */
52 if (request_irq(0, timer_interrupt, flags, "timer", NULL))
53 pr_info("Failed to register legacy timer interrupt\n");
54 }
55
56 /* Default timer init function */
57 void __init hpet_time_init(void)
58 {
59 if (!hpet_enable()) {
60 if (!pit_timer_init())
61 return;
62 }
63
64 setup_default_timer_irq();
65 }
66
67 static __init void x86_late_time_init(void)
68 {
69 /*
70 * Before PIT/HPET init, select the interrupt mode. This is required
71 * to make the decision whether PIT should be initialized correct.
72 */
73 x86_init.irqs.intr_mode_select();
74
75 /* Setup the legacy timers */
76 x86_init.timers.timer_init();
77
78 /*
79 * After PIT/HPET timers init, set up the final interrupt mode for
80 * delivering IRQs.
81 */
82 x86_init.irqs.intr_mode_init();
83 tsc_init();
84
85 if (static_cpu_has(X86_FEATURE_WAITPKG))
86 use_tpause_delay();
87 }
88
89 /*
90 * Initialize TSC and delay the periodic timer init to
91 * late x86_late_time_init() so ioremap works.
92 */
93 void __init time_init(void)
94 {
95 late_time_init = x86_late_time_init;
96 }
97
98 /*
99 * Sanity check the vdso related archdata content.
100 */
101 void clocksource_arch_init(struct clocksource *cs)
102 {
103 if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
104 return;
105
106 if (cs->mask != CLOCKSOURCE_MASK(64)) {
107 pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
108 cs->name, cs->mask);
109 cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
110 }
111 }
112
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