Messages in this thread Patch in this message | | | Date | Wed, 2 Mar 2011 18:46:03 GMT | From | tip-bot for Cyrill Gorcunov <> | Subject | [tip:perf/core] x86, nmi: Define a name for NMI control port |
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Commit-ID: 0f5dbad5ecab0921911966e857eab408ef32163c Gitweb: http://git.kernel.org/tip/0f5dbad5ecab0921911966e857eab408ef32163c Author: Cyrill Gorcunov <gorcunov@openvz.org> AuthorDate: Wed, 2 Mar 2011 18:32:30 +0300 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 2 Mar 2011 16:44:44 +0100
x86, nmi: Define a name for NMI control port
Also add a comment about why we need in/out operations.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Don Zickus <dzickus@redhat.com> Cc: Huang Ying <ying.huang@intel.com> LKML-Reference: <4D6E630E.1070107@openvz.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- arch/x86/include/asm/mach_traps.h | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/mach_traps.h b/arch/x86/include/asm/mach_traps.h index 72a8b52..7775deb 100644 --- a/arch/x86/include/asm/mach_traps.h +++ b/arch/x86/include/asm/mach_traps.h @@ -8,6 +8,7 @@ #include <asm/mc146818rtc.h> #define NMI_REASON_PORT 0x61 +#define NMI_ENABLE_PORT 0x70 /* Real-Time Clock Address Register as well */ #define NMI_REASON_SERR 0x80 #define NMI_REASON_IOCHK 0x40 @@ -30,12 +31,19 @@ static inline void reassert_nmi(void) old_reg = current_lock_cmos_reg(); else lock_cmos(0); /* register doesn't matter here */ - outb(0x8f, 0x70); - inb(0x71); /* dummy */ - outb(0x0f, 0x70); - inb(0x71); /* dummy */ + + /* + * This will cause the NMI output to transition low + * then high if there are any pending NMI sources. The + * CPU's NMI input logic will then register a new NMI. + */ + outb(0x8f, NMI_ENABLE_PORT); + inb(0x71); /* dummy */ + outb(0x0f, NMI_ENABLE_PORT); + inb(0x71); /* dummy */ + if (old_reg >= 0) - outb(old_reg, 0x70); + outb(old_reg, NMI_ENABLE_PORT); else unlock_cmos(); }
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