Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] [17/28] x86: MCE: Add table driven machine check grading | Date | Tue, 7 Apr 2009 17:07:59 +0200 (CEST) |
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Impact: Feature
The machine check grading (as in deciding what should be done for a given register value) has to be done multiple times soon and it's also getting more complicated. So it makes sense to consolidate it into a single function. To get smaller and more straight forward and possibly more extensible code I opted towards a new table driven method. The various rules are put into a table when is then executed by a very simple interpreter.
The grading engine is in a new file mce-severity.c. I also added a private include file mce-internal.h, because mce.h is already a bit too cluttered.
This is dead code right now, but will be used in followon patches.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- arch/x86/kernel/cpu/mcheck/Makefile | 1 arch/x86/kernel/cpu/mcheck/mce-internal.h | 10 ++++ arch/x86/kernel/cpu/mcheck/mce-severity.c | 61 ++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+)
Index: linux/arch/x86/kernel/cpu/mcheck/mce-severity.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux/arch/x86/kernel/cpu/mcheck/mce-severity.c 2009-04-07 16:43:08.000000000 +0200 @@ -0,0 +1,61 @@ +/* + * MCE grading rules. + * Copyright 2008, 2009 Intel Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + * + * Author: Andi Kleen + */ +#include <linux/kernel.h> +#include <asm/mce.h> + +#include "mce-internal.h" + +/* + * Grade an mce by severity. In general the most severe ones are processed + * first. Since there are quite a lot of combinations test the bits in a + * table-driven way. The rules are simply processed in order, first + * match wins. + */ + +static struct severity { + u64 mask; + u64 result; + unsigned char sev; + unsigned char mcgmask; + unsigned char mcgres; + char *msg; +} severities[] = { +#define SEV(s) .sev = MCE_ ## s ## _SEVERITY +#define BITCLR(x, s, m, r...) { .mask = x, .result = 0, SEV(s), .msg = m, ## r } +#define BITSET(x, s, m, r...) { .mask = x, .result = x, SEV(s), .msg = m, ## r } +#define MCGMASK(x, res, s, m, r...) \ + { .mcgmask = x, .mcgres = res, SEV(s), .msg = m, ## r } + BITCLR(MCI_STATUS_VAL, NO, "Invalid"), + BITCLR(MCI_STATUS_EN, NO, "Not enabled"), + BITSET(MCI_STATUS_PCC, PANIC, "Processor context corrupt"), + MCGMASK(MCG_STATUS_RIPV, 0, PANIC, "No restart IP"), + BITSET(MCI_STATUS_UC|MCI_STATUS_OVER, PANIC, "Overflowed uncorrected"), + BITSET(MCI_STATUS_UC, UC, "Uncorrected"), + BITSET(0, SOME, "No match") /* always matches. keep at end */ +}; + +int mce_severity(struct mce *a, int tolerant, char **msg) +{ + struct severity *s; + for (s = severities;; s++) { + if ((a->status & s->mask) != s->result) + continue; + if ((a->mcgstatus & s->mcgmask) != s->mcgres) + continue; + if (s->sev > MCE_NO_SEVERITY && (a->status & MCI_STATUS_UC) && + tolerant < 1) + return MCE_PANIC_SEVERITY; + if (msg) + *msg = s->msg; + return s->sev; + } +} Index: linux/arch/x86/kernel/cpu/mcheck/Makefile =================================================================== --- linux.orig/arch/x86/kernel/cpu/mcheck/Makefile 2009-04-07 16:09:53.000000000 +0200 +++ linux/arch/x86/kernel/cpu/mcheck/Makefile 2009-04-07 16:43:09.000000000 +0200 @@ -5,3 +5,4 @@ obj-$(CONFIG_X86_MCE_AMD) += mce_amd_64.o obj-$(CONFIG_X86_MCE_NONFATAL) += non-fatal.o obj-$(CONFIG_X86_MCE_THRESHOLD) += threshold.o +obj-$(CONFIG_X86_64) += mce-severity.o Index: linux/arch/x86/kernel/cpu/mcheck/mce-internal.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux/arch/x86/kernel/cpu/mcheck/mce-internal.h 2009-04-07 16:43:08.000000000 +0200 @@ -0,0 +1,10 @@ +#include <asm/mce.h> + +enum severity_level { + MCE_NO_SEVERITY, + MCE_SOME_SEVERITY, + MCE_UC_SEVERITY, + MCE_PANIC_SEVERITY, +}; + +int mce_severity(struct mce *a, int tolerant, char **msg);
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