linux-kernel - [PATCH] x86/cpu: Update cached HLE state on write to TSX_CTRL_CPUID

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Date:   Fri, 10 Jan 2020 14:50:54 -0800
From:   Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Borislav Petkov <bp@...en8.de>
Cc:     Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
        x86@...nel.org, Josh Poimboeuf <jpoimboe@...hat.com>,
        Tony Luck <tony.luck@...el.com>,
        Michal Hocko <mhocko@...e.com>, linux-kernel@...r.kernel.org,
        Neelima Krishnan <neelima.krishnan@...el.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>
Subject: [PATCH] x86/cpu: Update cached HLE state on write to
 TSX_CTRL_CPUID_CLEAR

/proc/cpuinfo currently reports Hardware Lock Elision (HLE) feature to
be present on boot cpu even if it was disabled during the bootup. This
is because cpuinfo_x86->x86_capability HLE bit is not updated after TSX
state is changed via a new MSR IA32_TSX_CTRL.

Update the cached HLE bit also since it is expected to change after an
update to CPUID_CLEAR bit in MSR IA32_TSX_CTRL.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@...el.com>
Reviewed-by: Dave Hansen <dave.hansen@...ux.intel.com>
---
 arch/x86/kernel/cpu/tsx.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c
index 3e20d322bc98..032509adf9de 100644
--- a/arch/x86/kernel/cpu/tsx.c
+++ b/arch/x86/kernel/cpu/tsx.c
@@ -115,11 +115,12 @@ void __init tsx_init(void)
 		tsx_disable();
 
 		/*
-		 * tsx_disable() will change the state of the
-		 * RTM CPUID bit.  Clear it here since it is now
-		 * expected to be not set.
+		 * tsx_disable() will change the state of the RTM and HLE CPUID
+		 * bits. Clear them here since they are now expected to be not
+		 * set.
 		 */
 		setup_clear_cpu_cap(X86_FEATURE_RTM);
+		setup_clear_cpu_cap(X86_FEATURE_HLE);
 	} else if (tsx_ctrl_state == TSX_CTRL_ENABLE) {
 
 		/*
@@ -131,10 +132,10 @@ void __init tsx_init(void)
 		tsx_enable();
 
 		/*
-		 * tsx_enable() will change the state of the
-		 * RTM CPUID bit.  Force it here since it is now
-		 * expected to be set.
+		 * tsx_enable() will change the state of the RTM and HLE CPUID
+		 * bits. Force them here since they are now expected to be set.
 		 */
 		setup_force_cpu_cap(X86_FEATURE_RTM);
+		setup_force_cpu_cap(X86_FEATURE_HLE);
 	}
 }
-- 
2.21.1