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authorSuresh Siddha <suresh.b.siddha@intel.com>2009-03-16 17:04:59 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2009-03-17 15:42:28 -0700
commit7c6d9f9785d156d0438401ef270322da3d5247db (patch)
tree43836c9bbce7ad270b3e5e34cf469e0210c5d2a9
parent2e93456f5c069cf889c0c3acd1246ee88c49ae5c (diff)
x86, x2apic: use virtual wire A mode in disable_IO_APIC() with interrupt-remapping
Impact: make kexec work with x2apic disable_IO_APIC() gets called during crashdump aswell, which configures the IO-APIC/LAPIC so that legacy interrupts can be delivered for the kexec'd kernel. In the presence of interrupt-remapping, we need to change the interrupt-remapping configuration aswell as modifying IO-APIC for virtual wire B mode. To keep things simple during the crash, use virtual wire A mode (for which we don't need to touch io-apic and interrupt-remapping tables). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--arch/x86/kernel/apic/io_apic.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index b18a7734d68..4d975d0e358 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2040,8 +2040,13 @@ void disable_IO_APIC(void)
* If the i8259 is routed through an IOAPIC
* Put that IOAPIC in virtual wire mode
* so legacy interrupts can be delivered.
+ *
+ * With interrupt-remapping, for now we will use virtual wire A mode,
+ * as virtual wire B is little complex (need to configure both
+ * IOAPIC RTE aswell as interrupt-remapping table entry).
+ * As this gets called during crash dump, keep this simple for now.
*/
- if (ioapic_i8259.pin != -1) {
+ if (ioapic_i8259.pin != -1 && !intr_remapping_enabled) {
struct IO_APIC_route_entry entry;
memset(&entry, 0, sizeof(entry));
@@ -2061,7 +2066,10 @@ void disable_IO_APIC(void)
ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
}
- disconnect_bsp_APIC(ioapic_i8259.pin != -1);
+ /*
+ * Use virtual wire A mode when interrupt remapping is enabled.
+ */
+ disconnect_bsp_APIC(!intr_remapping_enabled && ioapic_i8259.pin != -1);
}
#ifdef CONFIG_X86_32