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i386: Use global flag to disable broken local apic timer on AMD CPUs. 

The Averatec 2370 and some other Turion laptop BIOS seems to program the
ENABLE_C1E MSR inconsistently between cores. This confuses the lapic
use heuristics because when C1E is enabled anywhere it seems to affect
the complete chip.

Use a global flag instead of a per cpu flag to handle this.
If any CPU has C1E enabled disabled lapic use.

Thanks to Cal Peake for debugging.

Cc: tglx@linutronix.de
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andi Kleen 2007-08-10 22:31:07 +02:00 committed by Linus Torvalds
parent d2d0251f6f
commit d3f7eae182
4 changed files with 13 additions and 8 deletions
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10
arch/i386/kernel/apic.c
View File

@ -61,8 +61,9 @@ static int enable_local_apic __initdata = 0;
/* Local APIC timer verification ok */
static int local_apic_timer_verify_ok;
/* Disable local APIC timer from the kernel commandline or via dmi quirk */
static int local_apic_timer_disabled;
/* Disable local APIC timer from the kernel commandline or via dmi quirk
or using CPU MSR check */
int local_apic_timer_disabled;
/* Local APIC timer works in C2 */
int local_apic_timer_c2_ok;
EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
@ -370,12 +371,9 @@ void __init setup_boot_APIC_clock(void)
long delta, deltapm;
int pm_referenced = 0;
if (boot_cpu_has(X86_FEATURE_LAPIC_TIMER_BROKEN))
local_apic_timer_disabled = 1;
/*
* The local apic timer can be disabled via the kernel
* commandline or from the test above. Register the lapic
* commandline or from the CPU detection code. Register the lapic
* timer as a dummy clock event source on SMP systems, so the
* broadcast mechanism is used. On UP systems simply ignore it.
*/

7
arch/i386/kernel/cpu/amd.c
View File

@ -3,6 +3,7 @@
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/apic.h>
#include "cpu.h"
@ -22,6 +23,7 @@
extern void vide(void);
__asm__(".align 4\nvide: ret");
#ifdef CONFIG_X86_LOCAL_APIC
#define ENABLE_C1E_MASK 0x18000000
#define CPUID_PROCESSOR_SIGNATURE 1
#define CPUID_XFAM 0x0ff00000
@ -52,6 +54,7 @@ static __cpuinit int amd_apic_timer_broken(void)
}
return 0;
}
#endif
int force_mwait __cpuinitdata;
@ -282,8 +285,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
num_cache_leaves = 3;
}
#ifdef CONFIG_X86_LOCAL_APIC
if (amd_apic_timer_broken())
set_bit(X86_FEATURE_LAPIC_TIMER_BROKEN, c->x86_capability);
local_apic_timer_disabled = 1;
#endif
if (c->x86 == 0x10 && !force_mwait)
clear_bit(X86_FEATURE_MWAIT, c->x86_capability);

2
include/asm-i386/apic.h
View File

@ -116,6 +116,8 @@ extern void enable_NMI_through_LVT0 (void * dummy);
extern int timer_over_8254;
extern int local_apic_timer_c2_ok;
extern int local_apic_timer_disabled;
#else /* !CONFIG_X86_LOCAL_APIC */
static inline void lapic_shutdown(void) { }

2
include/asm-i386/cpufeature.h
View File

@ -79,7 +79,7 @@
#define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */
#define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
#define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
#define X86_FEATURE_LAPIC_TIMER_BROKEN (3*32+ 14) /* lapic timer broken in C1 */
/* 14 free */
#define X86_FEATURE_SYNC_RDTSC (3*32+15) /* RDTSC synchronizes the CPU */
#define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well on this CPU */