x86/voyager: fix compile breakage caused by dc1e35c6e95e8923cf1d3510438b63c600fee1e2

Impact: build fix on x86/Voyager

Given commits like this:

| Author: Suresh Siddha <[e-mail]>
| 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 <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/Kconfig

···
 
 	  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

···
 
 #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

···
 	/*
 	 * 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();