[PATCH v4 22/24] x86/cpufeatures: Add feature bit for HRESET

[Ricardo Neri]

The HRESET instruction isolates the classification of individual
tasks when they run sequentially on the same logical processor. It resets
the classification history that the logical processor maintains.

Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Ionela Voinescu <ionela.voinescu@xxxxxxx>
Cc: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Lukasz Luba <lukasz.luba@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Perry Yuan <Perry.Yuan@xxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tim C. Chen <tim.c.chen@xxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: Zhao Liu <zhao1.liu@xxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
---
Changes since v3:
 * Moved definition of HRESET to its correct leaf: CPUID_7_1_EAX (Zhao)

Changes since v2:
 * None

Changes since v1:
 * None
---
 arch/x86/include/asm/cpufeatures.h | 1 +
 arch/x86/include/asm/msr-index.h   | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 98a84cbf4261..5edb63af2996 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -319,6 +319,7 @@
 #define X86_FEATURE_FSRC		(12*32+12) /* "" Fast short REP {CMPSB,SCASB} */
 #define X86_FEATURE_LKGS		(12*32+18) /* "" Load "kernel" (userspace) GS */
 #define X86_FEATURE_AMX_FP16		(12*32+21) /* "" AMX fp16 Support */
+#define X86_FEATURE_HRESET		(12*32+22) /* Hardware history reset instruction */
 #define X86_FEATURE_AVX_IFMA            (12*32+23) /* "" Support for VPMADD52[H,L]UQ */
 #define X86_FEATURE_LAM			(12*32+26) /* Linear Address Masking */
 
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 7823b87bf383..605c01539b0d 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1111,6 +1111,9 @@
 #define MSR_IA32_HW_FEEDBACK_THREAD_CONFIG 0x17d4
 #define MSR_IA32_HW_FEEDBACK_CHAR	0x17d2
 
+/* Hardware History Reset  */
+#define MSR_IA32_HW_HRESET_ENABLE	0x17da
+
 /* x2APIC locked status */
 #define MSR_IA32_XAPIC_DISABLE_STATUS	0xBD
 #define LEGACY_XAPIC_DISABLED		BIT(0) /*
-- 
2.25.1