From 7c6d9f9785d156d0438401ef270322da3d5247db Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 16 Mar 2009 17:04:59 -0700 Subject: [PATCH] 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 Cc: Eric W. Biederman Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apic/io_apic.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index b18a7734d689..4d975d0e3588 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 -- 2.30.2