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Diffstat (limited to 'arch/x86/kernel/time.c')
| -rw-r--r-- | arch/x86/kernel/time.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c new file mode 100644 index 000000000..e42faa792 --- /dev/null +++ b/arch/x86/kernel/time.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 1991,1992,1995 Linus Torvalds + * Copyright (c) 1994 Alan Modra + * Copyright (c) 1995 Markus Kuhn + * Copyright (c) 1996 Ingo Molnar + * Copyright (c) 1998 Andrea Arcangeli + * Copyright (c) 2002,2006 Vojtech Pavlik + * Copyright (c) 2003 Andi Kleen + * + */ + +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/i8253.h> +#include <linux/time.h> +#include <linux/export.h> + +#include <asm/vsyscall.h> +#include <asm/x86_init.h> +#include <asm/i8259.h> +#include <asm/timer.h> +#include <asm/hpet.h> +#include <asm/time.h> + +unsigned long profile_pc(struct pt_regs *regs) +{ + unsigned long pc = instruction_pointer(regs); + + if (!user_mode(regs) && in_lock_functions(pc)) { +#ifdef CONFIG_FRAME_POINTER + return *(unsigned long *)(regs->bp + sizeof(long)); +#else + unsigned long *sp = (unsigned long *)regs->sp; + /* + * Return address is either directly at stack pointer + * or above a saved flags. Eflags has bits 22-31 zero, + * kernel addresses don't. + */ + if (sp[0] >> 22) + return sp[0]; + if (sp[1] >> 22) + return sp[1]; +#endif + } + return pc; +} +EXPORT_SYMBOL(profile_pc); + +/* + * Default timer interrupt handler for PIT/HPET + */ +static irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + global_clock_event->event_handler(global_clock_event); + return IRQ_HANDLED; +} + +static void __init setup_default_timer_irq(void) +{ + unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER; + + /* + * Unconditionally register the legacy timer interrupt; even + * without legacy PIC/PIT we need this for the HPET0 in legacy + * replacement mode. + */ + if (request_irq(0, timer_interrupt, flags, "timer", NULL)) + pr_info("Failed to register legacy timer interrupt\n"); +} + +/* Default timer init function */ +void __init hpet_time_init(void) +{ + if (!hpet_enable()) { + if (!pit_timer_init()) + return; + } + + setup_default_timer_irq(); +} + +static __init void x86_late_time_init(void) +{ + /* + * Before PIT/HPET init, select the interrupt mode. This is required + * to make the decision whether PIT should be initialized correct. + */ + x86_init.irqs.intr_mode_select(); + + /* Setup the legacy timers */ + x86_init.timers.timer_init(); + + /* + * After PIT/HPET timers init, set up the final interrupt mode for + * delivering IRQs. + */ + x86_init.irqs.intr_mode_init(); + tsc_init(); + + if (static_cpu_has(X86_FEATURE_WAITPKG)) + use_tpause_delay(); +} + +/* + * Initialize TSC and delay the periodic timer init to + * late x86_late_time_init() so ioremap works. + */ +void __init time_init(void) +{ + late_time_init = x86_late_time_init; +} + +/* + * Sanity check the vdso related archdata content. + */ +void clocksource_arch_init(struct clocksource *cs) +{ + if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE) + return; + + if (cs->mask != CLOCKSOURCE_MASK(64)) { + pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n", + cs->name, cs->mask); + cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE; + } +} |