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