[PATCH v2 2/6] x86/split_lock: Add and export split_lock_detect_set()

[Xiaoyao Li]

Add and export split_lock_detect_set(), which will be used by KVM module
to change the MSR_TEST_CTRL.SPLIT_LOCK_DETECT bit to switch SLD.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
 arch/x86/include/asm/cpu.h  | 1 +
 arch/x86/kernel/cpu/intel.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 167d0539e0ad..b46262afa6c1 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -52,6 +52,7 @@ extern enum split_lock_detect_state get_split_lock_detect_state(void);
 extern void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c);
 extern void switch_to_sld(unsigned long tifn);
 extern bool handle_user_split_lock(struct pt_regs *regs, long error_code);
+extern void split_lock_detect_set(bool on);
 #else
 static inline enum split_lock_detect_state get_split_lock_detect_state(void)
 {
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index a810cd022db5..44138dd64808 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1088,6 +1088,12 @@ void switch_to_sld(unsigned long tifn)
 	__sld_msr_set(!(tifn & _TIF_SLD));
 }
 
+void split_lock_detect_set(bool on)
+{
+	__sld_msr_set(on);
+}
+EXPORT_SYMBOL_GPL(split_lock_detect_set);
+
 #define SPLIT_LOCK_CPU(model) {X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY}
 
 /*
-- 
2.23.0