[patch V3 12/25] x86/cpu: Move arch_smt_update() to a neutral place

From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Nadav Amit <namit@vmware.com>,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
	Stephane Eranian <eranian@google.com>,
	Feng Tang <feng.tang@intel.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [patch V3 12/25] x86/cpu: Move arch_smt_update() to a neutral place
Date: Mon, 22 Jul 2019 20:47:17 +0200	[thread overview]
Message-ID: <20190722105219.910317273@linutronix.de> (raw)
In-Reply-To: 20190722104705.550071814@linutronix.de

arch_smt_update() will be used to control IPI/NMI broadcasting via the
shorthand mechanism. Keeping it in the bugs file and calling the apic
function from there is possible, but not really intuitive.

Move it to a neutral place and invoke the bugs function from there.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/bugs.h  |    2 ++
 arch/x86/kernel/cpu/bugs.c   |    2 +-
 arch/x86/kernel/cpu/common.c |    9 +++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/bugs.h
+++ b/arch/x86/include/asm/bugs.h
@@ -18,4 +18,6 @@ int ppro_with_ram_bug(void);
 static inline int ppro_with_ram_bug(void) { return 0; }
 #endif
 
+extern void cpu_bugs_smt_update(void);
+
 #endif /* _ASM_X86_BUGS_H */
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -700,7 +700,7 @@ static void update_mds_branch_idle(void)
 
 #define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
 
-void arch_smt_update(void)
+void cpu_bugs_smt_update(void)
 {
 	/* Enhanced IBRS implies STIBP. No update required. */
 	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1905,3 +1905,12 @@ void microcode_check(void)
 	pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
 	pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
 }
+
+/*
+ * Invoked from core CPU hotplug code after hotplug operations
+ */
+void arch_smt_update(void)
+{
+	/* Handle the speculative execution misfeatures */
+	cpu_bugs_smt_update();
+}


