1 /* 2 * Copyright (c) 1991,1992,1995 Linus Torvalds 3 * Copyright (c) 1994 Alan Modra 4 * Copyright (c) 1995 Markus Kuhn 5 * Copyright (c) 1996 Ingo Molnar 6 * Copyright (c) 1998 Andrea Arcangeli 7 * Copyright (c) 2002,2006 Vojtech Pavlik 8 * Copyright (c) 2003 Andi Kleen 9 * 10 */ 11 12 #include <linux/clockchips.h> 13 #include <linux/interrupt.h> 14 #include <linux/i8253.h> 15 #include <linux/time.h> 16 #include <linux/export.h> 17 18 #include <asm/vsyscall.h> 19 #include <asm/x86_init.h> 20 #include <asm/i8259.h> 21 #include <asm/timer.h> 22 #include <asm/hpet.h> 23 #include <asm/time.h> 24 25 #ifdef CONFIG_X86_64 26 __visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES; 27 #endif 28 29 unsigned long profile_pc(struct pt_regs *regs) 30 { 31 unsigned long pc = instruction_pointer(regs); 32 33 if (!user_mode(regs) && in_lock_functions(pc)) { 34 #ifdef CONFIG_FRAME_POINTER 35 return *(unsigned long *)(regs->bp + sizeof(long)); 36 #else 37 unsigned long *sp = 38 (unsigned long *)kernel_stack_pointer(regs); 39 /* 40 * Return address is either directly at stack pointer 41 * or above a saved flags. Eflags has bits 22-31 zero, 42 * kernel addresses don't. 43 */ 44 if (sp[0] >> 22) 45 return sp[0]; 46 if (sp[1] >> 22) 47 return sp[1]; 48 #endif 49 } 50 return pc; 51 } 52 EXPORT_SYMBOL(profile_pc); 53 54 /* 55 * Default timer interrupt handler for PIT/HPET 56 */ 57 static irqreturn_t timer_interrupt(int irq, void *dev_id) 58 { 59 global_clock_event->event_handler(global_clock_event); 60 return IRQ_HANDLED; 61 } 62 63 static struct irqaction irq0 = { 64 .handler = timer_interrupt, 65 .flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER, 66 .name = "timer" 67 }; 68 69 void __init setup_default_timer_irq(void) 70 { 71 if (!nr_legacy_irqs()) 72 return; 73 setup_irq(0, &irq0); 74 } 75 76 /* Default timer init function */ 77 void __init hpet_time_init(void) 78 { 79 if (!hpet_enable()) 80 setup_pit_timer(); 81 setup_default_timer_irq(); 82 } 83 84 static __init void x86_late_time_init(void) 85 { 86 x86_init.timers.timer_init(); 87 tsc_init(); 88 } 89 90 /* 91 * Initialize TSC and delay the periodic timer init to 92 * late x86_late_time_init() so ioremap works. 93 */ 94 void __init time_init(void) 95 { 96 late_time_init = x86_late_time_init; 97 } 98