[PATCH 3.16 041/410] x86/cpufeatures: Add Intel feature bits for Speculation Control

[Ben Hutchings]

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: David Woodhouse <dwmw@xxxxxxxxxxxx>

commit fc67dd70adb711a45d2ef34e12d1a8be75edde61 upstream.

Add three feature bits exposed by new microcode on Intel CPUs for
speculation control.

Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Cc: gnomes@xxxxxxxxxxxxxxxxxxx
Cc: ak@xxxxxxxxxxxxxxx
Cc: ashok.raj@xxxxxxxxx
Cc: dave.hansen@xxxxxxxxx
Cc: karahmed@xxxxxxxxx
Cc: arjan@xxxxxxxxxxxxxxx
Cc: torvalds@xxxxxxxxxxxxxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: bp@xxxxxxxxx
Cc: pbonzini@xxxxxxxxxx
Cc: tim.c.chen@xxxxxxxxxxxxxxx
Cc: gregkh@xxxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/1516896855-7642-3-git-send-email-dwmw@xxxxxxxxxxxx
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: This CPUID word wasn't used at all yet, so
 add it as feature word 10]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/cpufeature.h | 7 ++++++-
 arch/x86/kernel/cpu/common.c      | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -8,7 +8,7 @@
 #include <asm/required-features.h>
 #endif
 
-#define NCAPINTS	10	/* N 32-bit words worth of info */
+#define NCAPINTS	11	/* N 32-bit words worth of info */
 #define NBUGINTS	1	/* N 32-bit bug flags */
 
 /*
@@ -234,6 +234,11 @@
 #define X86_FEATURE_AVX512ER	(9*32+27) /* AVX-512 Exponential and Reciprocal */
 #define X86_FEATURE_AVX512CD	(9*32+28) /* AVX-512 Conflict Detection */
 
+/* Intel-defined CPU features, CPUID level 0x00000007:0 (EDX), word 10 */
+#define X86_FEATURE_SPEC_CTRL		(10*32+26) /* Speculation Control (IBRS + IBPB) */
+#define X86_FEATURE_STIBP		(10*32+27) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_ARCH_CAPABILITIES	(10*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
+
 /*
  * BUG word(s)
  */
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -701,6 +701,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
 
 		c->x86_capability[9] = ebx;
+		c->x86_capability[10] = edx;
 	}
 
 	/* AMD-defined flags: level 0x80000001 */