[patch 3/4] x86_64: add genapic_force

Add genapic_force. Used by the next Intel quirks patch.

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
---

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index 8e78a75..b007433 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -33,7 +33,7 @@ extern struct genapic apic_flat;
 extern struct genapic apic_physflat;
 
 struct genapic *genapic = &apic_flat;
-
+struct genapic *genapic_force;
 
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
@@ -46,6 +46,13 @@ void __init clustered_apic_check(void)
        u8 cluster_cnt[NUM_APIC_CLUSTERS];
        int max_apic = 0;
 
+       /* genapic selection can be forced because of certain quirks.
+        */
+       if (genapic_force) {
+               genapic = genapic_force;
+               goto print;
+       }
+
 #if defined(CONFIG_ACPI)
        /*
         * Some x86_64 machines use physical APIC mode regardless of how many
diff --git a/include/asm-x86_64/genapic.h b/include/asm-x86_64/genapic.h
index a0e9a4b..b80f4bb 100644
--- a/include/asm-x86_64/genapic.h
+++ b/include/asm-x86_64/genapic.h
@@ -30,6 +30,6 @@ struct genapic {
 };
 
 
-extern struct genapic *genapic;
+extern struct genapic *genapic, *genapic_force, apic_flat;
 
 #endif