x86/ioapic: Add proper checks to setp/enable_IO_APIC()

No point to have the same checks at every call site. Add them to the
functions, so they can be called unconditionally.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211703.490719938@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e5e00f509f03..f4dc2462a1ac 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1507,7 +1507,10 @@ void __init enable_IO_APIC(void)
         int i8259_apic, i8259_pin;
         int apic, pin;
 
-        if (!nr_legacy_irqs())
+        if (skip_ioapic_setup)
+                nr_ioapics = 0;
+
+        if (!nr_legacy_irqs() || !nr_ioapics)
                 return;
 
         for_each_ioapic_pin(apic, pin) {
@@ -2373,9 +2376,9 @@ void __init setup_IO_APIC(void)
 {
         int ioapic;
 
-        /*
-         * calling enable_IO_APIC() is moved to setup_local_APIC for BP
-         */
+        if (skip_ioapic_setup || !nr_ioapics)
+                return;
+
         io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
 
         apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");