intel_idle: Use __update_spec_ctrl() in intel_idle_ibrs()

When intel_idle_ibrs() is called, it modifies the SPEC_CTRL MSR to 0
in order disable IBRS. However, the new MSR value isn't reflected in
x86_spec_ctrl_current which is at odd with the other code that keep track
of its state in that percpu variable.  Use the new __update_spec_ctrl()
to have the x86_spec_ctrl_current percpu value properly updated.

Since spec-ctrl.h includes both msr.h and nospec-branch.h, we can remove
those from the include file list.

Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

drivers/idle/intel_idle.c

@@ -53,9 +53,8 @@
 #include <linux/moduleparam.h>
 #include <asm/cpu_device_id.h>
 #include <asm/intel-family.h>
-#include <asm/nospec-branch.h>
 #include <asm/mwait.h>
-#include <asm/msr.h>
+#include <asm/spec-ctrl.h>
 #include <asm/fpu/api.h>
 
 #define INTEL_IDLE_VERSION "0.5.1"
@@ -182,12 +181,12 @@ static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev,
 	int ret;
 
 	if (smt_active)
-		native_wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+		__update_spec_ctrl(0);
 
 	ret = __intel_idle(dev, drv, index);
 
 	if (smt_active)
-		native_wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
+		__update_spec_ctrl(spec_ctrl);
 
 	return ret;
 }