Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 apic updates from Ingo Molnar:
 "The main x86 APIC/IOAPIC changes in this cycle were:

   - Robustify kexec support to more carefully restore IRQ hardware
     state before calling into kexec/kdump kernels. (Baoquan He)

   - Clean up the local APIC code a bit (Dou Liyang)

   - Remove unused callbacks (David Rientjes)"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Finish removing unused callbacks
  x86/apic: Drop logical_smp_processor_id() inline
  x86/apic: Modernize the pending interrupt code
  x86/apic: Move pending interrupt check code into it's own function
  x86/apic: Set up through-local-APIC mode on the boot CPU if 'noapic' specified
  x86/apic: Rename variables and functions related to x86_io_apic_ops
  x86/apic: Remove the (now) unused disable_IO_APIC() function
  x86/apic: Fix restoring boot IRQ mode in reboot and kexec/kdump
  x86/apic: Split disable_IO_APIC() into two functions to fix CONFIG_KEXEC_JUMP=y
  x86/apic: Split out restore_boot_irq_mode() from disable_IO_APIC()
  x86/apic: Make setup_local_APIC() static
  x86/apic: Simplify init_bsp_APIC() usage
  x86/x2apic: Mark set_x2apic_phys_mode() as __init

1 files changed, 7 insertions, 2 deletions

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++)