x86: Always use x86_cpu_to_logical_apicid for cpu -> logical apic id

Currently, cpu -> logical apic id translation is done by
apic->cpu_to_logical_apicid() callback which may or may not use
x86_cpu_to_logical_apicid.  This is unnecessary as it should
always equal logical_smp_processor_id() which is known early
during CPU bring up.

Initialize x86_cpu_to_logical_apicid after apic->init_apic_ldr()
in setup_local_APIC() and always use x86_cpu_to_logical_apicid
for cpu -> logical apic id mapping.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-6-git-send-email-tj@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/apic.c

@@ -1248,6 +1248,14 @@ void __cpuinit setup_local_APIC(void)
 	 */
 	apic->init_apic_ldr();
 
+#ifdef CONFIG_X86_32
+	/*
+	 * APIC LDR is initialized.  Fetch and store logical_apic_id.
+	 */
+	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
+		logical_smp_processor_id();
+#endif
+
 	/*
 	 * Set Task Priority to 'accept all'. We never change this
 	 * later on.

arch/x86/kernel/apic/ipi.c

@@ -73,8 +73,8 @@ void default_send_IPI_mask_sequence_logical(const struct cpumask *mask,
 	local_irq_save(flags);
 	for_each_cpu(query_cpu, mask)
 		__default_send_IPI_dest_field(
-			apic->cpu_to_logical_apicid(query_cpu), vector,
-			apic->dest_logical);
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, apic->dest_logical);
 	local_irq_restore(flags);
 }
 
@@ -92,8 +92,8 @@ void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask,
 		if (query_cpu == this_cpu)
 			continue;
 		__default_send_IPI_dest_field(
-			apic->cpu_to_logical_apicid(query_cpu), vector,
-			apic->dest_logical);
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, apic->dest_logical);
 		}
 	local_irq_restore(flags);
 }

arch/x86/kernel/smpboot.c

@@ -168,19 +168,18 @@ static void unmap_cpu_to_node(int cpu)
 static void map_cpu_to_logical_apicid(void)
 {
 	int cpu = smp_processor_id();
-	int apicid = logical_smp_processor_id();
-	int node = apic->apicid_to_node(apicid);
+	int logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
+	int node;
 
+	node = apic->apicid_to_node(logical_apicid);
 	if (!node_online(node))
 		node = first_online_node;
 
-	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = apicid;
 	map_cpu_to_node(cpu, node);
 }
 
 void numa_remove_cpu(int cpu)
 {
-	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = BAD_APICID;
 	unmap_cpu_to_node(cpu);
 }
 #else