linux/arch/x86/kernel/time.c
Linus Torvalds 034bda1cd5 Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 vdso updates from Ingo Molnar:
 "Two main changes:

   - Cleanups, simplifications and CLOCK_TAI support (Thomas Gleixner)

   - Improve code generation (Andy Lutomirski)"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Rearrange do_hres() to improve code generation
  x86/vdso: Document vgtod_ts better
  x86/vdso: Remove "memory" clobbers in the vDSO syscall fallbacks
  x66/vdso: Add CLOCK_TAI support
  x86/vdso: Move cycle_last handling into the caller
  x86/vdso: Simplify the invalid vclock case
  x86/vdso: Replace the clockid switch case
  x86/vdso: Collapse coarse functions
  x86/vdso: Collapse high resolution functions
  x86/vdso: Introduce and use vgtod_ts
  x86/vdso: Use unsigned int consistently for vsyscall_gtod_data:: Seq
  x86/vdso: Enforce 64bit clocksource
  x86/time: Implement clocksource_arch_init()
  clocksource: Provide clocksource_arch_init()
2018-10-23 19:07:25 +01:00

130 lines
3.0 KiB
C

// 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>
#ifdef CONFIG_X86_64
__visible volatile unsigned long jiffies __cacheline_aligned_in_smp = INITIAL_JIFFIES;
#endif
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 *)kernel_stack_pointer(regs);
/*
* 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 struct irqaction irq0 = {
.handler = timer_interrupt,
.flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
.name = "timer"
};
static void __init setup_default_timer_irq(void)
{
/*
* Unconditionally register the legacy timer; even without legacy
* PIC/PIT we need this for the HPET0 in legacy replacement mode.
*/
if (setup_irq(0, &irq0))
pr_info("Failed to register legacy timer interrupt\n");
}
/* Default timer init function */
void __init hpet_time_init(void)
{
if (!hpet_enable())
setup_pit_timer();
setup_default_timer_irq();
}
static __init void x86_late_time_init(void)
{
x86_init.timers.timer_init();
/*
* After PIT/HPET timers init, select and setup
* the final interrupt mode for delivering IRQs.
*/
x86_init.irqs.intr_mode_init();
tsc_init();
}
/*
* 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->archdata.vclock_mode == VCLOCK_NONE)
return;
if (cs->archdata.vclock_mode > VCLOCK_MAX) {
pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
cs->name, cs->archdata.vclock_mode);
cs->archdata.vclock_mode = VCLOCK_NONE;
}
if (cs->mask != CLOCKSOURCE_MASK(64)) {
pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
cs->name, cs->mask);
cs->archdata.vclock_mode = VCLOCK_NONE;
}
}