[PATCH v6 3/4] intel_idle: Use __update_spec_ctrl() in intel_idle_ibrs()

Waiman Long
2023-07-27T18:48:06Z

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 <longman@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/idle/intel_idle.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 256c2d42e350..d286f31a5b96 100644
--- a/drivers/idle/intel_idle.c
+++ b/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;
}
--
2.31.1