Use the state information to simplify the disable logic further. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) Index: tip/arch/x86/kernel/apic/apic.c =================================================================== --- tip.orig/arch/x86/kernel/apic/apic.c +++ tip/arch/x86/kernel/apic/apic.c @@ -1545,26 +1545,21 @@ void x2apic_setup(void) static __init void x2apic_disable(void) { - u64 msr; + u32 x2apic_id; - if (!cpu_has_x2apic) - return; + if (x2apic_state != X2APIC_ON) + goto out; - rdmsrl(MSR_IA32_APICBASE, msr); - if (msr & X2APIC_ENABLE) { - u32 x2apic_id = read_apic_id(); + x2apic_id = read_apic_id(); + if (x2apic_id >= 255) + panic("Cannot disable x2apic, id: %08x\n", x2apic_id); - if (x2apic_id >= 255) - panic("Cannot disable x2apic, id: %08x\n", x2apic_id); - - disable_x2apic(); - - x2apic_mode = 0; - - register_lapic_address(mp_lapic_addr); - } + disable_x2apic(); + register_lapic_address(mp_lapic_addr); +out: x2apic_state = X2APIC_DISABLED; + x2apic_mode = 0; } static __init void x2apic_enable(void)