thermal: intel: intel_tcc_cooling: Detect TCC lock bit

When MSR_IA32_TEMPERATURE_TARGET is locked, TCC Offset can not be
updated even if the PROGRAMMABE Bit is set.

Yield the driver on platforms with MSR_IA32_TEMPERATURE_TARGET locked.

Signed-off-by: Zhang Rui <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

Author: zhang-rui

drivers/thermal/intel/intel_tcc_cooling.c

@@ -14,6 +14,7 @@
 #define TCC_SHIFT 24
 #define TCC_MASK	(0x3fULL<<24)
 #define TCC_PROGRAMMABLE	BIT(30)
+#define TCC_LOCKED		BIT(31)
 
 static struct thermal_cooling_device *tcc_cdev;
 
@@ -108,6 +109,15 @@ static int __init tcc_cooling_init(void)
 	if (!(val & TCC_PROGRAMMABLE))
 		return -ENODEV;
 
+	err = rdmsrl_safe(MSR_IA32_TEMPERATURE_TARGET, &val);
+	if (err)
+		return err;
+
+	if (val & TCC_LOCKED) {
+		pr_info("TCC Offset locked\n");
+		return -ENODEV;
+	}
+
 	pr_info("Programmable TCC Offset detected\n");
 
 	tcc_cdev =