2010-12-13 16:51:26

by Cliff Wickman

Subject: [PATCH] x86: use native_halt on a halt

halt() should use native_halt()
safe_halt() uses native_safe_halt()

If CONFIG_PARAVIRT=y, halt() is defined in arch/x86/include/asm/paravirt.h as

static inline void halt(void)
{
PVOP_VCALL0(pv_irq_ops.safe_halt);
}

Otherwise (no CONFIG_PARAVIRT) halt() in arch/x86/include/asm/irqflags.h is

static inline void halt(void)
{
native_halt();
}

So it looks to me like the CONFIG_PARAVIRT case of using native_safe_halt()
for a halt() is an oversight.
Am I missing something?

It probably hasn't shown up as a problem because the local apic is disabled
on a shutdown or restart. But if we disable interrupts and call halt()
we shouldn't expect that the halt() will re-enable interrupts.

Signed-off-by: Cliff Wickman <[email protected]>

---
arch/x86/include/asm/paravirt.h | 2 +-
arch/x86/kernel/apic/apic.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

Index: linux/arch/x86/include/asm/paravirt.h
===================================================================
--- linux.orig/arch/x86/include/asm/paravirt.h
+++ linux/arch/x86/include/asm/paravirt.h
@@ -112,7 +112,7 @@ static inline void raw_safe_halt(void)

static inline void halt(void)
{
- PVOP_VCALL0(pv_irq_ops.safe_halt);
+ PVOP_VCALL0(pv_irq_ops.halt);
}

static inline void wbinvd(void)

2010-12-27 23:03:20

by Cliff Wickman

Subject: [tip:x86/paravirt] x86, paravirt: Use native_halt on a halt, not native_safe_halt

Commit-ID: c8217b8305e5e75c23617f2f4cd262527d952c0a
Gitweb: http://git.kernel.org/tip/c8217b8305e5e75c23617f2f4cd262527d952c0a
Author: Cliff Wickman <[email protected]>
AuthorDate: Mon, 13 Dec 2010 10:51:57 -0600
Committer: H. Peter Anvin <[email protected]>
CommitDate: Mon, 27 Dec 2010 14:02:11 -0800

x86, paravirt: Use native_halt on a halt, not native_safe_halt

halt() should use native_halt()
safe_halt() uses native_safe_halt()

If CONFIG_PARAVIRT=y, halt() is defined in arch/x86/include/asm/paravirt.h as

static inline void halt(void)
{
PVOP_VCALL0(pv_irq_ops.safe_halt);
}

Otherwise (no CONFIG_PARAVIRT) halt() in arch/x86/include/asm/irqflags.h is

static inline void halt(void)
{
native_halt();
}

So it looks to me like the CONFIG_PARAVIRT case of using native_safe_halt()
for a halt() is an oversight.
Am I missing something?

It probably hasn't shown up as a problem because the local apic is disabled
on a shutdown or restart. But if we disable interrupts and call halt()
we shouldn't expect that the halt() will re-enable interrupts.

Signed-off-by: Cliff Wickman <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
arch/x86/include/asm/paravirt.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index ef99758..7709c12 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -112,7 +112,7 @@ static inline void arch_safe_halt(void)

static inline void halt(void)
{
- PVOP_VCALL0(pv_irq_ops.safe_halt);
+ PVOP_VCALL0(pv_irq_ops.halt);
}

static inline void wbinvd(void)