Revert "x86, apic: Use logical flat on intel with <= 8 logical cpus"

Revert commit 2fbd07a5f5, as this commit
breaks an IBM platform with quad-core Xeon cpu's.

According to Suresh, this might be an IBM platform issue, as on other
Intel platforms with <= 8 logical cpu's, logical flat mode works fine
irespective of physical apic id values (inline with the xapic
architecture).

Revert this for now because of the IBM platform breakage.

Another version will be re-submitted after the complete analysis.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/apic/probe_64.c

@@ -64,23 +64,16 @@ void __init default_setup_apic_routing(void)
 			apic = &apic_x2apic_phys;
 		else
 			apic = &apic_x2apic_cluster;
+		printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
 	}
 #endif
 
 	if (apic == &apic_flat) {
-		switch (boot_cpu_data.x86_vendor) {
-		case X86_VENDOR_INTEL:
-			if (num_processors > 8)
-				apic = &apic_physflat;
-			break;
-		case X86_VENDOR_AMD:
-			if (max_physical_apicid >= 8)
-				apic = &apic_physflat;
-		}
+		if (max_physical_apicid >= 8)
+			apic = &apic_physflat;
+		printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
 	}
 
-	printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
-
 	if (is_vsmp_box()) {
 		/* need to update phys_pkg_id */
 		apic->phys_pkg_id = apicid_phys_pkg_id;