x86: check command line when CONFIG_X86_MPPARSE is not set, v2

if acpi=off, acpi=noirq and pci=noacpi, we need to disable apic.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index a93300de4da9..175c696ec536 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -302,6 +302,11 @@ void __init setup_arch(char **cmdline_p)
 
         parse_early_param();
 
+        if (acpi_mps_check()) {
+                disable_apic = 1;
+                clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
+        }
+
 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
         if (init_ohci1394_dma_early)
                 init_ohci1394_dma_on_all_controllers();
@@ -723,6 +728,10 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
                 cpu_devs[c->x86_vendor]->c_early_init(c);
 
         validate_pat_support(c);
+
+        /* early_param could clear that, but recall get it set again */
+        if (disable_apic)
+                clear_cpu_cap(c, X86_FEATURE_APIC);
 }
 
 /*