x86, cpu: Add a synthetic, always true, cpu feature

This will be used in alternatives later as an always-replace flag.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1370772454-6106-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/cpufeature.h

@@ -92,7 +92,7 @@
 #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* "" Lfence synchronizes RDTSC */
 #define X86_FEATURE_11AP	(3*32+19) /* "" Bad local APIC aka 11AP */
 #define X86_FEATURE_NOPL	(3*32+20) /* The NOPL (0F 1F) instructions */
-					  /* 21 available, was AMD_C1E */
+#define X86_FEATURE_ALWAYS	(3*32+21) /* "" Always-present feature */
 #define X86_FEATURE_XTOPOLOGY	(3*32+22) /* cpu topology enum extensions */
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */

arch/x86/kernel/cpu/common.c

@@ -723,6 +723,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 
 	if (this_cpu->c_bsp_init)
 		this_cpu->c_bsp_init(c);
+
+	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
 }
 
 void __init early_cpu_init(void)