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 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 = 41 (unsigned long *)kernel_stack_pointer(regs); 42 /* 43 * Return address is either directly at stack pointer 44 * or above a saved flags. Eflags has bits 22-31 zero, 45 * kernel addresses don't. 46 */ 47 if (sp[0] >> 22) 48 return sp[0]; 49 if (sp[1] >> 22) 50 return sp[1]; 51 #endif 52 } 53 return pc; 54 } 55 EXPORT_SYMBOL(profile_pc); 56 57 /* 58 * Default timer interrupt handler for PIT/HPET 59 */ 60 static irqreturn_t timer_interrupt(int irq, void *dev_id) 61 { 62 global_clock_event->event_handler(global_clock_event); 63 return IRQ_HANDLED; 64 } 65 66 static struct irqaction irq0 = { 67 .handler = timer_interrupt, 68 .flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER, 69 .name = "timer" 70 }; 71 72 static void __init setup_default_timer_irq(void) 73 { 74 /* 75 * Unconditionally register the legacy timer; even without legacy 76 * PIC/PIT we need this for the HPET0 in legacy replacement mode. 77 */ 78 if (setup_irq(0, &irq0)) 79 pr_info("Failed to register legacy timer interrupt\n"); 80 } 81 82 /* Default timer init function */ 83 void __init hpet_time_init(void) 84 { 85 if (!hpet_enable()) 86 setup_pit_timer(); 87 setup_default_timer_irq(); 88 } 89 90 static __init void x86_late_time_init(void) 91 { 92 x86_init.timers.timer_init(); 93 /* 94 * After PIT/HPET timers init, select and setup 95 * the final interrupt mode for delivering IRQs. 96 */ 97 x86_init.irqs.intr_mode_init(); 98 tsc_init(); 99 } 100 101 /* 102 * Initialize TSC and delay the periodic timer init to 103 * late x86_late_time_init() so ioremap works. 104 */ 105 void __init time_init(void) 106 { 107 late_time_init = x86_late_time_init; 108 } 109 110 /* 111 * Sanity check the vdso related archdata content. 112 */ 113 void clocksource_arch_init(struct clocksource *cs) 114 { 115 if (cs->archdata.vclock_mode == VCLOCK_NONE) 116 return; 117 118 if (cs->archdata.vclock_mode > VCLOCK_MAX) { 119 pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n", 120 cs->name, cs->archdata.vclock_mode); 121 cs->archdata.vclock_mode = VCLOCK_NONE; 122 } 123 124 if (cs->mask != CLOCKSOURCE_MASK(64)) { 125 pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n", 126 cs->name, cs->mask); 127 cs->archdata.vclock_mode = VCLOCK_NONE; 128 } 129 } 130