Commit c86c7fbc authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Ingo Molnar
Browse files

x86: disable hpet on shutdown 



If HPET was enabled by pci quirks, we use i8253 as initial clockevent
because pci quirks doesn't run until pci is initialized.

The above means the kernel (or something) is assuming HPET legacy
replacement is disabled and can use i8253 at boot.

If we used kexec, it isn't true. So, this patch disables HPET legacy
replacement for kexec in machine_shutdown().

Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 92d499d9

arch/x86/kernel/hpet.c

+14 −0
Original line number Diff line number Diff line
@@ -446,6 +446,20 @@ static __init int hpet_late_init(void) 
}

fs_initcall(hpet_late_init);



void hpet_disable(void)

{

	if (is_hpet_capable()) {

		unsigned long cfg = hpet_readl(HPET_CFG);



		if (hpet_legacy_int_enabled) {

			cfg &= ~HPET_CFG_LEGACY;

			hpet_legacy_int_enabled = 0;

		}

		cfg &= ~HPET_CFG_ENABLE;

		hpet_writel(cfg, HPET_CFG);

	}

}



#ifdef CONFIG_HPET_EMULATE_RTC



/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET

arch/x86/kernel/reboot_32.c

+4 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/reboot.h>

#include <asm/uaccess.h>

#include <asm/apic.h>

#include <asm/hpet.h>

#include <asm/desc.h>

#include "mach_reboot.h"

#include <asm/reboot_fixups.h>
@@ -326,6 +327,9 @@ static void native_machine_shutdown(void) 
#ifdef CONFIG_X86_IO_APIC

	disable_IO_APIC();

#endif

#ifdef CONFIG_HPET_TIMER

	hpet_disable();

#endif

}



void __attribute__((weak)) mach_reboot_fixups(void)

arch/x86/kernel/reboot_64.c

+4 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <asm/pgtable.h>

#include <asm/tlbflush.h>

#include <asm/apic.h>

#include <asm/hpet.h>

#include <asm/gart.h>



/*
@@ -113,6 +114,9 @@ void machine_shutdown(void) 


	disable_IO_APIC();



#ifdef CONFIG_HPET_TIMER

	hpet_disable();

#endif

	local_irq_restore(flags);



	pci_iommu_shutdown();

include/asm-x86/hpet.h

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ extern unsigned long force_hpet_address; 
extern int hpet_force_user;

extern int is_hpet_enabled(void);

extern int hpet_enable(void);

extern void hpet_disable(void);

extern unsigned long hpet_readl(unsigned long a);

extern void force_hpet_resume(void);

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