[PATCH 2/2] x86/speculation: switch_to_cond_stibp on is the likely case

From: Waiman Long <longman@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Waiman Long <longman@redhat.com>
Subject: [PATCH 2/2] x86/speculation: switch_to_cond_stibp on is the likely case
Date: Wed,  5 Dec 2018 14:49:28 -0500	[thread overview]
Message-ID: <1544039368-9009-2-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1544039368-9009-1-git-send-email-longman@redhat.com>

Since conditional STIBP is the default, it should be treated as
the likely case. Changes the use of static_branch_unlikely() to
static_branch_likely() for switch_to_cond_stibp.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 arch/x86/kernel/cpu/bugs.c | 2 +-
 arch/x86/kernel/process.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index a68b32c..bd11119 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -153,7 +153,7 @@ void __init check_bugs(void)
 			hostval |= ssbd_tif_to_spec_ctrl(ti->flags);
 
 		/* Conditional STIBP enabled? */
-		if (static_branch_unlikely(&switch_to_cond_stibp))
+		if (static_branch_likely(&switch_to_cond_stibp))
 			hostval |= stibp_tif_to_spec_ctrl(ti->flags);
 
 		if (hostval != guestval) {
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 7d31192..39a21ae 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -434,7 +434,7 @@ static __always_inline void __speculation_ctrl_update(unsigned long tifp,
 	 * otherwise avoid the MSR write.
 	 */
 	if (IS_ENABLED(CONFIG_SMP) &&
-	    static_branch_unlikely(&switch_to_cond_stibp)) {
+	    static_branch_likely(&switch_to_cond_stibp)) {
 		updmsr |= !!(tif_diff & _TIF_SPEC_IB);
 		msr |= stibp_tif_to_spec_ctrl(tifn);
 	}
-- 
1.8.3.1

