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[PATCH] kexec: x86: local apic fix 

From: "Maciej W. Rozycki" <macro@linux-mips.org>

Fix a kexec problem whcih causes local APIC detection failure.

The problem is detect_init_APIC() is called early, before the command line
have been processed.  Therefore "lapic" (and "nolapic") have not been seen,
yet.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Eric W. Biederman 2005-06-25 14:57:41 -07:00 committed by Linus Torvalds
parent 8f43d03fe2
commit 9635b47d91
3 changed files with 29 additions and 20 deletions
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25
arch/i386/kernel/apic.c
View File

@ -40,6 +40,11 @@
#include "io_ports.h"
/*
* Knob to control our willingness to enable the local APIC.
*/
int enable_local_apic __initdata = 0; /* -1=force-disable, +1=force-enable */
/*
* Debug level
*/
@ -666,26 +671,6 @@ static void apic_pm_activate(void) { }
* Original code written by Keir Fraser.
*/
/*
* Knob to control our willingness to enable the local APIC.
*/
int enable_local_apic __initdata = 0; /* -1=force-disable, +1=force-enable */
static int __init lapic_disable(char *str)
{
enable_local_apic = -1;
clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
return 0;
}
__setup("nolapic", lapic_disable);
static int __init lapic_enable(char *str)
{
enable_local_apic = 1;
return 0;
}
__setup("lapic", lapic_enable);
static int __init apic_set_verbosity(char *str)
{
if (strcmp("debug", str) == 0)

11
arch/i386/kernel/setup.c
View File

@ -44,6 +44,7 @@
#include <linux/edd.h>
#include <linux/nodemask.h>
#include <video/edid.h>
#include <asm/apic.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
@ -835,6 +836,16 @@ static void __init parse_cmdline_early (char ** cmdline_p)
#endif /* CONFIG_X86_LOCAL_APIC */
#endif /* CONFIG_ACPI_BOOT */
#ifdef CONFIG_X86_LOCAL_APIC
/* enable local APIC */
else if (!memcmp(from, "lapic", 5))
lapic_enable();
/* disable local APIC */
else if (!memcmp(from, "nolapic", 6))
lapic_disable();
#endif /* CONFIG_X86_LOCAL_APIC */
/*
* highmem=size forces highmem to be exactly 'size' bytes.
* This works even on boxes that have no highmem otherwise.

13
include/asm-i386/apic.h
View File

@ -5,6 +5,7 @@
#include <linux/pm.h>
#include <asm/fixmap.h>
#include <asm/apicdef.h>
#include <asm/processor.h>
#include <asm/system.h>
#define Dprintk(x...)
@ -16,8 +17,20 @@
#define APIC_VERBOSE 1
#define APIC_DEBUG 2
extern int enable_local_apic;
extern int apic_verbosity;
static inline void lapic_disable(void)
{
enable_local_apic = -1;
clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
}
static inline void lapic_enable(void)
{
enable_local_apic = 1;
}
/*
* Define the default level of output to be very little
* This can be turned up by using apic=verbose for more