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: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 53303f2..4a86ffd 100644 (file)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -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

diff --git a/arch/x86/kernel/reboot_32.c b/arch/x86/kernel/reboot_32.c
index 9e2269d..bb1a0f8 100644 (file)
--- a/arch/x86/kernel/reboot_32.c
+++ b/arch/x86/kernel/reboot_32.c
@@ -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)

diff --git a/arch/x86/kernel/reboot_64.c b/arch/x86/kernel/reboot_64.c
index 71b13c5..53620a9 100644 (file)
--- a/arch/x86/kernel/reboot_64.c
+++ b/arch/x86/kernel/reboot_64.c
@@ -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();

diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h
index b1f3c1e..ad8d6e7 100644 (file)
--- a/include/asm-x86/hpet.h
+++ b/include/asm-x86/hpet.h
@@ -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);