From ccf5355d05cd891522267f04b2723002e7f061de Mon Sep 17 00:00:00 2001 From: Dou Liyang Date: Wed, 17 Jan 2018 15:37:48 +0800 Subject: x86/apic: Simplify init_bsp_APIC() usage Since CONFIG_X86_64 selects CONFIG_X86_LOCAL_APIC, the following condition: #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC) is equivalent to: #if defined(CONFIG_X86_LOCAL_APIC) ... and we can eliminate that #ifdef by providing an empty init_bsp_APIC() stub in the !CONFIG_X86_LOCAL_APIC case. Also add some comments to explain why we call init_bsp_APIC(). Signed-off-by: Dou Liyang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: mroos@linux.ee Cc: ville.syrjala@linux.intel.com Link: http://lkml.kernel.org/r/20180117073748.23905-1-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/irqinit.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/irqinit.c') diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index a539410c4ea9..772196c1b8c4 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -61,9 +61,14 @@ void __init init_ISA_irqs(void) struct irq_chip *chip = legacy_pic->chip; int i; -#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC) + /* + * Try to set up the through-local-APIC virtual wire mode earlier. + * + * On some 32-bit UP machines, whose APIC has been disabled by BIOS + * and then got re-enabled by "lapic", it hangs at boot time without this. + */ init_bsp_APIC(); -#endif + legacy_pic->init(0); for (i = 0; i < nr_legacy_irqs(); i++) -- cgit 1.4.1