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/clockchips.h> 14 #include <linux/interrupt.h> 15 #include <linux/i8253.h> 16 #include <linux/time.h> 17 #include <linux/export.h> 18 19 #include <asm/vsyscall.h> 20 #include <asm/x86_init.h> 21 #include <asm/i8259.h> 22 #include <asm/timer.h> 23 #include <asm/hpet.h> 24 #include <asm/time.h> 25 26 #ifdef CONFIG_X86_64 27 __visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES; 28 #endif 29 30 unsigned long profile_pc(struct pt_regs *regs) 31 { 32 unsigned long pc = instruction_pointer(regs); 33 34 if (!user_mode(regs) && in_lock_functions(pc)) { 35 #ifdef CONFIG_FRAME_POINTER 36 return *(unsigned long *)(regs->bp + sizeof(long)); 37 #else 38 unsigned long *sp = 39 (unsigned long *)kernel_stack_pointer(regs); 40 /* 41 * Return address is either directly at stack pointer 42 * or above a saved flags. Eflags has bits 22-31 zero, 43 * kernel addresses don't. 44 */ 45 if (sp[0] >> 22) 46 return sp[0]; 47 if (sp[1] >> 22) 48 return sp[1]; 49 #endif 50 } 51 return pc; 52 } 53 EXPORT_SYMBOL(profile_pc); 54 55 /* 56 * Default timer interrupt handler for PIT/HPET 57 */ 58 static irqreturn_t timer_interrupt(int irq, void *dev_id) 59 { 60 global_clock_event->event_handler(global_clock_event); 61 return IRQ_HANDLED; 62 } 63 64 static struct irqaction irq0 = { 65 .handler = timer_interrupt, 66 .flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER, 67 .name = "timer" 68 }; 69 70 static void __init setup_default_timer_irq(void) 71 { 72 /* 73 * Unconditionally register the legacy timer; even without legacy 74 * PIC/PIT we need this for the HPET0 in legacy replacement mode. 75 */ 76 if (setup_irq(0, &irq0)) 77 pr_info("Failed to register legacy timer interrupt\n"); 78 } 79 80 /* Default timer init function */ 81 void __init hpet_time_init(void) 82 { 83 if (!hpet_enable()) 84 setup_pit_timer(); 85 setup_default_timer_irq(); 86 } 87 88 static __init void x86_late_time_init(void) 89 { 90 x86_init.timers.timer_init(); 91 /* 92 * After PIT/HPET timers init, select and setup 93 * the final interrupt mode for delivering IRQs. 94 */ 95 x86_init.irqs.intr_mode_init(); 96 tsc_init(); 97 } 98 99 /* 100 * Initialize TSC and delay the periodic timer init to 101 * late x86_late_time_init() so ioremap works. 102 */ 103 void __init time_init(void) 104 { 105 late_time_init = x86_late_time_init; 106 } 107