ACPI: thermal: Simplify initialization of critical and hot trips

Use the observation that the critical and hot trip points are never
updated by the ACPI thermal driver, because the flags passed from
acpi_thermal_notify() to acpi_thermal_trips_update() do not include
ACPI_TRIPS_CRITICAL or ACPI_TRIPS_HOT, to move the initialization
of those trip points directly into acpi_thermal_get_trip_points() and
reduce the size of __acpi_thermal_trips_update().

Also make the critical and hot trip points initialization code more
straightforward and drop the flags that are not needed any more.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/acpi/thermal.c

@@ -43,17 +43,13 @@
 #define ACPI_THERMAL_MAX_ACTIVE		10
 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN	65
 
-#define ACPI_TRIPS_CRITICAL	BIT(0)
-#define ACPI_TRIPS_HOT		BIT(1)
-#define ACPI_TRIPS_PASSIVE	BIT(2)
-#define ACPI_TRIPS_ACTIVE	BIT(3)
-#define ACPI_TRIPS_DEVICES	BIT(4)
+#define ACPI_TRIPS_PASSIVE	BIT(0)
+#define ACPI_TRIPS_ACTIVE	BIT(1)
+#define ACPI_TRIPS_DEVICES	BIT(2)
 
 #define ACPI_TRIPS_THRESHOLDS	(ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 
-#define ACPI_TRIPS_INIT		(ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT | \
-				 ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE | \
-				 ACPI_TRIPS_DEVICES)
+#define ACPI_TRIPS_INIT		(ACPI_TRIPS_THRESHOLDS | ACPI_TRIPS_DEVICES)
 
 /*
  * This exception is thrown out in two cases:
@@ -196,62 +192,6 @@ static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 	bool valid = false;
 	int i;
 
-	/* Critical Shutdown */
-	if (flag & ACPI_TRIPS_CRITICAL) {
-		status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
-		tz->trips.critical.temperature = tmp;
-		/*
-		 * Treat freezing temperatures as invalid as well; some
-		 * BIOSes return really low values and cause reboots at startup.
-		 * Below zero (Celsius) values clearly aren't right for sure..
-		 * ... so lets discard those as invalid.
-		 */
-		if (ACPI_FAILURE(status)) {
-			tz->trips.critical.valid = false;
-			acpi_handle_debug(tz->device->handle,
-					  "No critical threshold\n");
-		} else if (tmp <= 2732) {
-			pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
-			tz->trips.critical.valid = false;
-		} else {
-			tz->trips.critical.valid = true;
-			acpi_handle_debug(tz->device->handle,
-					  "Found critical threshold [%lu]\n",
-					  tz->trips.critical.temperature);
-		}
-		if (tz->trips.critical.valid) {
-			if (crt == -1) {
-				tz->trips.critical.valid = false;
-			} else if (crt > 0) {
-				unsigned long crt_k = celsius_to_deci_kelvin(crt);
-
-				/*
-				 * Allow override critical threshold
-				 */
-				if (crt_k > tz->trips.critical.temperature)
-					pr_info("Critical threshold %d C\n", crt);
-
-				tz->trips.critical.temperature = crt_k;
-			}
-		}
-	}
-
-	/* Critical Sleep (optional) */
-	if (flag & ACPI_TRIPS_HOT) {
-		status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
-		if (ACPI_FAILURE(status)) {
-			tz->trips.hot.valid = false;
-			acpi_handle_debug(tz->device->handle,
-					  "No hot threshold\n");
-		} else {
-			tz->trips.hot.temperature = tmp;
-			tz->trips.hot.valid = true;
-			acpi_handle_debug(tz->device->handle,
-					  "Found hot threshold [%lu]\n",
-					  tz->trips.hot.temperature);
-		}
-	}
-
 	/* Passive (optional) */
 	if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.trip.valid) ||
 	    flag == ACPI_TRIPS_INIT) {
@@ -451,11 +391,73 @@ static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
 					dev_name(&adev->dev), event, 0);
 }
 
+static void acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
+{
+	unsigned long long tmp;
+	acpi_status status;
+
+	if (crt > 0) {
+		tmp = celsius_to_deci_kelvin(crt);
+		goto set;
+	}
+	if (crt == -1) {
+		acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
+		goto fail;
+	}
+
+	status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_debug(tz->device->handle, "No critical threshold\n");
+		goto fail;
+	}
+	if (tmp <= 2732) {
+		/*
+		 * Below zero (Celsius) values clearly aren't right for sure,
+		 * so discard them as invalid.
+		 */
+		pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
+		goto fail;
+	}
+
+set:
+	tz->trips.critical.valid = true;
+	tz->trips.critical.temperature = tmp;
+	acpi_handle_debug(tz->device->handle, "Critical threshold [%lu]\n",
+			  tz->trips.critical.temperature);
+	return;
+
+fail:
+	tz->trips.critical.valid = false;
+	tz->trips.critical.temperature = THERMAL_TEMP_INVALID;
+}
+
+static void acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
+{
+	unsigned long long tmp;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
+	if (ACPI_FAILURE(status)) {
+		tz->trips.hot.valid = false;
+		tz->trips.hot.temperature = THERMAL_TEMP_INVALID;
+		acpi_handle_debug(tz->device->handle, "No hot threshold\n");
+		return;
+	}
+
+	tz->trips.hot.valid = true;
+	tz->trips.hot.temperature = tmp;
+	acpi_handle_debug(tz->device->handle, "Hot threshold [%lu]\n",
+			  tz->trips.hot.temperature);
+}
+
 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 {
 	bool valid;
 	int i;
 
+	acpi_thermal_get_critical_trip(tz);
+	acpi_thermal_get_hot_trip(tz);
+	/* Passive and active trip points (optional). */
 	__acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 
 	valid = tz->trips.critical.valid |