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 unsigned long pc = instruction_pointer(regs); 31 32 if (!user_mode(regs) && in_lock_functions(pc)) { 33 #ifdef CONFIG_FRAME_POINTER 34 return *(unsigned long *)(regs->bp + sizeof(long)); 35 #else 36 unsigned long *sp = (unsigned long *)regs->sp; 37 /* 38 * Return address is either directly at stack pointer 39 * or above a saved flags. Eflags has bits 22-31 zero, 40 * kernel addresses don't. 41 */ 42 if (sp[0] >> 22) 43 return sp[0]; 44 if (sp[1] >> 22) 45 return sp[1]; 46 #endif 47 } 48 return pc; 49 } 50 EXPORT_SYMBOL(profile_pc); 51 52 /* 53 * Default timer interrupt handler for PIT/HPET 54 */ 55 static irqreturn_t timer_interrupt(int irq, void *dev_id) 56 { 57 global_clock_event->event_handler(global_clock_event); 58 return IRQ_HANDLED; 59 } 60 61 static void __init setup_default_timer_irq(void) 62 { 63 unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER; 64 65 /* 66 * Unconditionally register the legacy timer interrupt; even 67 * without legacy PIC/PIT we need this for the HPET0 in legacy 68 * replacement mode. 69 */ 70 if (request_irq(0, timer_interrupt, flags, "timer", NULL)) 71 pr_info("Failed to register legacy timer interrupt\n"); 72 } 73 74 /* Default timer init function */ 75 void __init hpet_time_init(void) 76 { 77 if (!hpet_enable()) { 78 if (!pit_timer_init()) 79 return; 80 } 81 82 setup_default_timer_irq(); 83 } 84 85 static __init void x86_late_time_init(void) 86 { 87 /* 88 * Before PIT/HPET init, select the interrupt mode. This is required 89 * to make the decision whether PIT should be initialized correct. 90 */ 91 x86_init.irqs.intr_mode_select(); 92 93 /* Setup the legacy timers */ 94 x86_init.timers.timer_init(); 95 96 /* 97 * After PIT/HPET timers init, set up the final interrupt mode for 98 * delivering IRQs. 99 */ 100 x86_init.irqs.intr_mode_init(); 101 tsc_init(); 102 103 if (static_cpu_has(X86_FEATURE_WAITPKG)) 104 use_tpause_delay(); 105 } 106 107 /* 108 * Initialize TSC and delay the periodic timer init to 109 * late x86_late_time_init() so ioremap works. 110 */ 111 void __init time_init(void) 112 { 113 late_time_init = x86_late_time_init; 114 } 115 116 /* 117 * Sanity check the vdso related archdata content. 118 */ 119 void clocksource_arch_init(struct clocksource *cs) 120 { 121 if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE) 122 return; 123 124 if (cs->mask != CLOCKSOURCE_MASK(64)) { 125 pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n", 126 cs->name, cs->mask); 127 cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE; 128 } 129 } 130