x86: Fix build failure on X86_UP_APIC

Commit 4c321ff (x86: Replace cpu_2_logical_apicid[] with early
percpu variable) and following changes introduced and used
x86_cpu_to_logical_apicid percpu variable.  It was declared and
defined inside CONFIG_SMP && CONFIG_X86_32 but if
CONFIG_X86_UP_APIC is set UP configuration makes use of it and
build fails.

Fix it by declaring and defining it inside CONFIG_X86_LOCAL_APIC
&& CONFIG_X86_32.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
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: <20110128162248.GA25746@htj.dyndns.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/smp.h

@@ -38,7 +38,7 @@ static inline struct cpumask *cpu_core_mask(int cpu)
 
 DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid);
 DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid);
-#if defined(CONFIG_SMP) && defined(CONFIG_X86_32)
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
 DECLARE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid);
 #endif
 

arch/x86/kernel/apic/apic.c

@@ -79,15 +79,13 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 
 #ifdef CONFIG_X86_32
 
-#ifdef CONFIG_SMP
 /*
  * On x86_32, the mapping between cpu and logical apicid may vary
  * depending on apic in use.  The following early percpu variable is
  * used for the mapping.  This is where the behaviors of x86_64 and 32
  * actually diverge.  Let's keep it ugly for now.
  */
 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
-#endif
 
 /*
  * Knob to control our willingness to enable the local APIC.