x86/platform/UV: Add UV Architecture Defines

Add defines to control which UV architectures are supported, and modify the
'if (is_uvX_*)' functions to return constant 0 for those not supported.
This will help optimize code paths when support for specific UV arches
is removed.

Tested-by: John Estabrook <estabrook@sgi.com>
Tested-by: Gary Kroening <gfk@sgi.com>
Tested-by: Nathan Zimmer <nzimmer@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160429215402.897143440@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/uv/uv_hub.h

@@ -178,22 +178,43 @@ DECLARE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
 #define UV3_HUB_REVISION_BASE		5
 #define UV4_HUB_REVISION_BASE		7
 
+#ifdef	UV1_HUB_IS_SUPPORTED
 static inline int is_uv1_hub(void)
 {
 	return uv_hub_info->hub_revision < UV2_HUB_REVISION_BASE;
 }
+#else
+static inline int is_uv1_hub(void)
+{
+	return 0;
+}
+#endif
 
+#ifdef	UV2_HUB_IS_SUPPORTED
 static inline int is_uv2_hub(void)
 {
 	return ((uv_hub_info->hub_revision >= UV2_HUB_REVISION_BASE) &&
 		(uv_hub_info->hub_revision < UV3_HUB_REVISION_BASE));
 }
+#else
+static inline int is_uv2_hub(void)
+{
+	return 0;
+}
+#endif
 
+#ifdef	UV3_HUB_IS_SUPPORTED
 static inline int is_uv3_hub(void)
 {
 	return ((uv_hub_info->hub_revision >= UV3_HUB_REVISION_BASE) &&
 		(uv_hub_info->hub_revision < UV4_HUB_REVISION_BASE));
 }
+#else
+static inline int is_uv3_hub(void)
+{
+	return 0;
+}
+#endif
 
 #ifdef	UV4_HUB_IS_SUPPORTED
 static inline int is_uv4_hub(void)
@@ -207,15 +228,20 @@ static inline int is_uv4_hub(void)
 }
 #endif
 
-static inline int is_uv_hub(void)
+static inline int is_uvx_hub(void)
 {
-	return uv_hub_info->hub_revision;
+	if (uv_hub_info->hub_revision >= UV2_HUB_REVISION_BASE)
+		return uv_hub_info->hub_revision;
+
+	return 0;
 }
 
-/* code common to uv2/3/4 only */
-static inline int is_uvx_hub(void)
+static inline int is_uv_hub(void)
 {
-	return uv_hub_info->hub_revision >= UV2_HUB_REVISION_BASE;
+#ifdef	UV1_HUB_IS_SUPPORTED
+	return uv_hub_info->hub_revision;
+#endif
+	return is_uvx_hub();
 }
 
 union uvh_apicid {