On Wednesday 08 August 2007 02:53:21 Cal Peake wrote:
> On Wed, 8 Aug 2007, Andi Kleen wrote:
>
> > Not sure why the MSR varies between cores though.
>
> Yeah that boggled me too.
>
> > It's better to just make it a global instead.
>
> Haven't gotten to figuring out how to do *that* yet... but here's a
> cleanup for the detection function:
Can you please test if this patch works?
BTW I checked with AMD and they seem to think it's just a buggy BIOS.
-Andi
Use global flag to disable broken local apic timer on AMD CPUs.
The Averatec 2370 laptop BIOS seems to program the ENABLE_C1E
MSR inconsistently between cores. This confuses the lapic
use heuristics wants to know if C1E is enabled anywhere.
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.
Signed-off-by: Andi Kleen <[EMAIL PROTECTED]>
Index: linux/arch/i386/kernel/apic.c
===================================================================
--- linux.orig/arch/i386/kernel/apic.c
+++ linux/arch/i386/kernel/apic.c
@@ -61,8 +61,9 @@ static int enable_local_apic __initdata
/* 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);
@@ -370,9 +371,6 @@ 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
Index: linux/arch/i386/kernel/cpu/amd.c
===================================================================
--- linux.orig/arch/i386/kernel/cpu/amd.c
+++ linux/arch/i386/kernel/cpu/amd.c
@@ -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_brok
}
return 0;
}
+#endif
int force_mwait __cpuinitdata;
@@ -282,8 +285,10 @@ static void __cpuinit init_amd(struct cp
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);
Index: linux/include/asm-i386/apic.h
===================================================================
--- linux.orig/include/asm-i386/apic.h
+++ linux/include/asm-i386/apic.h
@@ -116,6 +116,8 @@ extern void enable_NMI_through_LVT0 (voi
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) { }
Index: linux/include/asm-i386/cpufeature.h
===================================================================
--- linux.orig/include/asm-i386/cpufeature.h
+++ linux/include/asm-i386/cpufeature.h
@@ -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 */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
