The vectors between FIRST_SYSTEM_VECTOR and NR_VECTORS are special IRQ vectors used by the SMP architecture. But, if X86_LOCAL_APIC=n, it will not be used, and the FIRST_SYSTEM_VECTOR is equal to NR_VECTORS.
idt_setup_apic_and_irq_gates() didn't notice that, which make the code a little complex. Remove the code of the X86_LOCAL_APIC=n case to simplify it. Signed-off-by: Dou Liyang <[email protected]> --- arch/x86/kernel/idt.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 2c3a1b4294eb..8b4174890706 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -317,15 +317,16 @@ void __init idt_setup_apic_and_irq_gates(void) set_intr_gate(i, entry); } - for_each_clear_bit_from(i, system_vectors, NR_VECTORS) { + /* + * If X86_LOCAL_APIC=n, the FIRST_SYSTEM_VECTOR is equal to NR_VECTORS + * Just consider the X86_LOCAL_APIC=y case + */ #ifdef CONFIG_X86_LOCAL_APIC + for_each_clear_bit_from(i, system_vectors, NR_VECTORS) { set_bit(i, system_vectors); set_intr_gate(i, spurious_interrupt); -#else - entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR); - set_intr_gate(i, entry); -#endif } +#endif } /** -- 2.14.3
