x86/voyager: fix compile breakage caused by dc1e35c6e9

Impact: build fix on x86/Voyager

Given commits like this:

| Author: Suresh Siddha <suresh.b.siddha@intel.com>
| Date:   Tue Jul 29 10:29:19 2008 -0700
|
|     x86, xsave: enable xsave/xrstor on cpus with xsave support

Which deliberately expose boot cpu dependence to pieces of the system,
I think it's time to explicitly have a variable for it to prevent this
continual misassumption that the boot CPU is zero.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/Kconfig

@@ -231,6 +231,10 @@ config SMP
 
 	  If you don't know what to do here, say N.
 
+config X86_HAS_BOOT_CPU_ID
+	def_bool y
+	depends on X86_VOYAGER
+
 config X86_FIND_SMP_CONFIG
 	def_bool y
 	depends on X86_MPPARSE || X86_VOYAGER

arch/x86/include/asm/smp.h

@@ -225,5 +225,11 @@ static inline int hard_smp_processor_id(void)
 
 #endif /* CONFIG_X86_LOCAL_APIC */
 
+#ifdef CONFIG_X86_HAS_BOOT_CPU_ID
+extern unsigned char boot_cpu_id;
+#else
+#define boot_cpu_id	0
+#endif
+
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_X86_SMP_H */

arch/x86/kernel/cpu/common.c

@@ -1134,7 +1134,7 @@ void __cpuinit cpu_init(void)
 	/*
 	 * Boot processor to setup the FP and extended state context info.
 	 */
-	if (!smp_processor_id())
+	if (smp_processor_id() == boot_cpu_id)
 		init_thread_xstate();
 
 	xsave_init();