mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
8c49d9a74b
Variables that are shared between the vdso and the kernel are currently a bit of a mess. They are each defined with their own magic, they are accessed differently in the kernel, the vsyscall page, and the vdso, and one of them (vsyscall_clock) doesn't even really exist. This changes them all to use a common mechanism. All of them are delcared in vvar.h with a fixed address (validated by the linker script). In the kernel (as before), they look like ordinary read-write variables. In the vsyscall page and the vdso, they are accessed through a new macro VVAR, which gives read-only access. The vdso is now loaded verbatim into memory without any fixups. As a side bonus, access from the vdso is faster because a level of indirection is removed. While we're at it, pack jiffies and vgetcpu_mode into the same cacheline. Signed-off-by: Andy Lutomirski <luto@mit.edu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@amd64.org> Link: http://lkml.kernel.org/r/%3C7357882fbb51fa30491636a7b6528747301b7ee9.1306156808.git.luto%40mit.edu%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
104 lines
2.2 KiB
C
104 lines
2.2 KiB
C
/*
|
|
* 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/clockchips.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/time.h>
|
|
#include <linux/mca.h>
|
|
|
|
#include <asm/vsyscall.h>
|
|
#include <asm/x86_init.h>
|
|
#include <asm/i8259.h>
|
|
#include <asm/i8253.h>
|
|
#include <asm/timer.h>
|
|
#include <asm/hpet.h>
|
|
#include <asm/time.h>
|
|
|
|
#ifdef CONFIG_X86_64
|
|
DEFINE_VVAR(volatile unsigned long, jiffies) = INITIAL_JIFFIES;
|
|
#endif
|
|
|
|
unsigned long profile_pc(struct pt_regs *regs)
|
|
{
|
|
unsigned long pc = instruction_pointer(regs);
|
|
|
|
if (!user_mode_vm(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)
|
|
{
|
|
/* Keep nmi watchdog up to date */
|
|
inc_irq_stat(irq0_irqs);
|
|
|
|
global_clock_event->event_handler(global_clock_event);
|
|
|
|
/* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
|
|
if (MCA_bus)
|
|
outb_p(inb_p(0x61)| 0x80, 0x61);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction irq0 = {
|
|
.handler = timer_interrupt,
|
|
.flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
|
|
.name = "timer"
|
|
};
|
|
|
|
void __init setup_default_timer_irq(void)
|
|
{
|
|
setup_irq(0, &irq0);
|
|
}
|
|
|
|
/* 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();
|
|
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;
|
|
}
|