[RFC PATCH v1 04/18] x86: Add the Secure Memory Encryption cpu feature

[Tom Lendacky <thomas.lendacky@amd.com>]

Update the cpu features to include identifying and reporting on the
Secure Memory Encryption feature.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/include/asm/cpufeature.h  |    1 +
 arch/x86/include/asm/cpufeatures.h |    5 ++++-
 arch/x86/kernel/cpu/scattered.c    |    1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 07c942d..e27e352 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -27,6 +27,7 @@ enum cpuid_leafs
 	CPUID_6_EAX,
 	CPUID_8000_000A_EDX,
 	CPUID_7_ECX,
+	CPUID_8000_001F_EAX,
 };
 
 #ifdef CONFIG_X86_FEATURE_NAMES
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 47b5056..4aea205 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -12,7 +12,7 @@
 /*
  * Defines x86 CPU feature bits
  */
-#define NCAPINTS	17	/* N 32-bit words worth of info */
+#define NCAPINTS	18	/* N 32-bit words worth of info */
 #define NBUGINTS	1	/* N 32-bit bug flags */
 
 /*
@@ -282,6 +282,9 @@
 #define X86_FEATURE_PKU		(16*32+ 3) /* Protection Keys for Userspace */
 #define X86_FEATURE_OSPKE	(16*32+ 4) /* OS Protection Keys Enable */
 
+/* AMD SME Feature Identification, CPUID level 0x8000001f (eax), word 17 */
+#define X86_FEATURE_SME		(17*32+ 0) /* Secure Memory Encryption support */
+
 /*
  * BUG word(s)
  */
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 8cb57df..d86d9a5 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -37,6 +37,7 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
 		{ X86_FEATURE_HW_PSTATE,	CR_EDX, 7, 0x80000007, 0 },
 		{ X86_FEATURE_CPB,		CR_EDX, 9, 0x80000007, 0 },
 		{ X86_FEATURE_PROC_FEEDBACK,	CR_EDX,11, 0x80000007, 0 },
+		{ X86_FEATURE_SME,		CR_EAX, 0, 0x8000001f, 0 },
 		{ 0, 0, 0, 0, 0 }
 	};