ACPI: boot correctly with "nosmp" or "maxcpus=0"

In MPS mode, "nosmp" and "maxcpus=0" boot a UP kernel with IOAPIC disabled.
However, in ACPI mode, these parameters didn't completely disable
the IO APIC initialization code and boot failed.

init/main.c:
	Disable the IO_APIC if "nosmp" or "maxcpus=0"
	undefine disable_ioapic_setup() when it doesn't apply.

i386:
	delete ioapic_setup(), it was a duplicate of parse_noapic()
	delete undefinition of disable_ioapic_setup()

x86_64:
	rename disable_ioapic_setup() to parse_noapic() to match i386
	define disable_ioapic_setup() in header to match i386

http://bugzilla.kernel.org/show_bug.cgi?id=1641

Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 3 insertions, 13 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 4b8a8da4b2e0..e2f4a1c68547 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -754,14 +754,6 @@ static int pirq_entries [MAX_PIRQS];
 static int pirqs_enabled;
 int skip_ioapic_setup;
 
-static int __init ioapic_setup(char *str)
-{
-        skip_ioapic_setup = 1;
-        return 1;
-}
-
-__setup("noapic", ioapic_setup);
-
 static int __init ioapic_pirq_setup(char *str)
 {
         int i, max;
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index f57f8b901912..966fa1062491 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -397,14 +397,12 @@ static void clear_IO_APIC (void)
 int skip_ioapic_setup;
 int ioapic_force;
 
-/* dummy parsing: see setup.c */
-
-static int __init disable_ioapic_setup(char *str)
+static int __init parse_noapic(char *str)
 {
-        skip_ioapic_setup = 1;
+        disable_ioapic_setup();
         return 0;
 }
-early_param("noapic", disable_ioapic_setup);
+early_param("noapic", parse_noapic);
 
 /* Actually the next is obsolete, but keep it for paranoid reasons -AK */
 static int __init disable_timer_pin_setup(char *arg)