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authorAndi Kleen <ak@suse.de>2008-01-30 13:33:17 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:33:17 +0100
commitd3432896dae72ee97deb850ad7bbc30329d32c0d (patch)
tree73cc99efc6ca0ef5f8caabd6eed1e2a50196ca5e
parentca74a6f84e68b44867022f4a4f3ec17c087c864e (diff)
x86: don't disable the APIC if it hasn't been mapped yet
When the kernel panics early for some unrelated reason there would be eventually an early exception inside panic because clear_local_APIC tried to disable the not yet mapped APIC. Check for that explicitely. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/kernel/apic_32.c11
-rw-r--r--arch/x86/kernel/apic_64.c9
2 files changed, 15 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index d07a603807d..35a568ea840 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -99,6 +99,8 @@ static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
/* Local APIC was disabled by the BIOS and enabled by the kernel */
static int enabled_via_apicbase;
+static unsigned long apic_phys;
+
/*
* Get the LAPIC version
*/
@@ -631,9 +633,14 @@ int setup_profiling_timer(unsigned int multiplier)
*/
void clear_local_APIC(void)
{
- int maxlvt = lapic_get_maxlvt();
+ int maxlvt;
u32 v;
+ /* APIC hasn't been mapped yet */
+ if (!apic_phys)
+ return;
+
+ maxlvt = lapic_get_maxlvt();
/*
* Masking an LVT entry can trigger a local APIC error
* if the vector is zero. Mask LVTERR first to prevent this.
@@ -1120,8 +1127,6 @@ no_apic:
*/
void __init init_apic_mappings(void)
{
- unsigned long apic_phys;
-
/*
* If no local APIC can be found then set up a fake all
* zeroes page to simulate the local APIC and another
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 85bd3d463cd..a7a38c9da13 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -81,6 +81,8 @@ static struct clock_event_device lapic_clockevent = {
};
static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
+static unsigned long apic_phys;
+
/*
* Get the LAPIC version
*/
@@ -525,6 +527,11 @@ void clear_local_APIC(void)
int maxlvt = lapic_get_maxlvt();
u32 v;
+ /* APIC hasn't been mapped yet */
+ if (!apic_phys)
+ return;
+
+ maxlvt = lapic_get_maxlvt();
/*
* Masking an LVT entry can trigger a local APIC error
* if the vector is zero. Mask LVTERR first to prevent this.
@@ -859,8 +866,6 @@ static int __init detect_init_APIC(void)
*/
void __init init_apic_mappings(void)
{
- unsigned long apic_phys;
-
/*
* If no local APIC can be found then set up a fake all
* zeroes page to simulate the local APIC and another