[PATCH 2/7] ACPI / PM: Move device power state selection routine to device_pm.c

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI function for choosing device power state is now located
in drivers/acpi/sleep.c, but drivers/acpi/device_pm.c is a more
logical place for it, so move it there.

However, instead of moving the function entirely, move its core only
under a different name and with a different list of arguments, so
that it is more flexible, and leave a wrapper around it in the
original location.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/device_pm.c |  107 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/sleep.c     |   88 +-------------------------------------
 include/acpi/acpi_bus.h  |   15 ++++++
 3 files changed, 124 insertions(+), 86 deletions(-)

Index: linux/drivers/acpi/device_pm.c
===================================================================
--- linux.orig/drivers/acpi/device_pm.c
+++ linux/drivers/acpi/device_pm.c
@@ -23,7 +23,9 @@
  */
 
 #include <linux/device.h>
+#include <linux/export.h>
 #include <linux/mutex.h>
+#include <linux/pm_qos.h>
 
 #include <acpi/acpi.h>
 #include <acpi/acpi_bus.h>
@@ -89,3 +91,108 @@ acpi_status acpi_remove_pm_notifier(stru
 	mutex_unlock(&acpi_pm_notifier_lock);
 	return status;
 }
+
+/**
+ * acpi_device_power_state - Get preferred power state of ACPI device.
+ * @dev: Device whose preferred target power state to return.
+ * @adev: ACPI device node corresponding to @dev.
+ * @target_state: System state to match the resultant device state.
+ * @d_max_in: Deepest low-power state to take into consideration.
+ * @d_min_p: Location to store the upper limit of the allowed states range.
+ * Return value: Preferred power state of the device on success, -ENODEV
+ * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ *
+ * Find the lowest power (highest number) ACPI device power state that the
+ * device can be in while the system is in the state represented by
+ * @target_state.  If @d_min_p is set, the highest power (lowest number) device
+ * power state that @dev can be in for the given system sleep state is stored
+ * at the location pointed to by it.
+ *
+ * Callers must ensure that @dev and @adev are valid pointers and that @adev
+ * actually corresponds to @dev before using this function.
+ */
+int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
+			    u32 target_state, int d_max_in, int *d_min_p)
+{
+	char acpi_method[] = "_SxD";
+	unsigned long long d_min, d_max;
+	bool wakeup = false;
+
+	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
+		return -EINVAL;
+
+	if (d_max_in > ACPI_STATE_D3_HOT) {
+		enum pm_qos_flags_status stat;
+
+		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
+		if (stat == PM_QOS_FLAGS_ALL)
+			d_max_in = ACPI_STATE_D3_HOT;
+	}
+
+	acpi_method[2] = '0' + target_state;
+	/*
+	 * If the sleep state is S0, the lowest limit from ACPI is D3,
+	 * but if the device has _S0W, we will use the value from _S0W
+	 * as the lowest limit from ACPI.  Finally, we will constrain
+	 * the lowest limit with the specified one.
+	 */
+	d_min = ACPI_STATE_D0;
+	d_max = ACPI_STATE_D3;
+
+	/*
+	 * If present, _SxD methods return the minimum D-state (highest power
+	 * state) we can use for the corresponding S-states.  Otherwise, the
+	 * minimum D-state is D0 (ACPI 3.x).
+	 *
+	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
+	 * provided -- that's our fault recovery, we ignore retval.
+	 */
+	if (target_state > ACPI_STATE_S0) {
+		acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
+		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
+			&& adev->wakeup.sleep_state >= target_state;
+	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
+			PM_QOS_FLAGS_NONE) {
+		wakeup = adev->wakeup.flags.valid;
+	}
+
+	/*
+	 * If _PRW says we can wake up the system from the target sleep state,
+	 * the D-state returned by _SxD is sufficient for that (we assume a
+	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
+	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
+	 * can wake the system.  _S0W may be valid, too.
+	 */
+	if (wakeup) {
+		acpi_status status;
+
+		acpi_method[3] = 'W';
+		status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
+						&d_max);
+		if (ACPI_FAILURE(status)) {
+			if (target_state != ACPI_STATE_S0 ||
+			    status != AE_NOT_FOUND)
+				d_max = d_min;
+		} else if (d_max < d_min) {
+			/* Warn the user of the broken DSDT */
+			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
+				acpi_method);
+			/* Sanitize it */
+			d_min = d_max;
+		}
+	}
+
+	if (d_max_in < d_min)
+		return -EINVAL;
+	if (d_min_p)
+		*d_min_p = d_min;
+	/* constrain d_max with specified lowest limit (max number) */
+	if (d_max > d_max_in) {
+		for (d_max = d_max_in; d_max > d_min; d_max--) {
+			if (adev->power.states[d_max].flags.valid)
+				break;
+		}
+	}
+	return d_max;
+}
+EXPORT_SYMBOL_GPL(acpi_device_power_state);
Index: linux/drivers/acpi/sleep.c
===================================================================
--- linux.orig/drivers/acpi/sleep.c
+++ linux/drivers/acpi/sleep.c
@@ -19,7 +19,6 @@
 #include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
-#include <linux/pm_qos.h>
 
 #include <asm/io.h>
 
@@ -706,101 +705,20 @@ int acpi_suspend(u32 acpi_state)
  * Return value: Preferred power state of the device on success, -ENODEV
  * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
  *
- * Find the lowest power (highest number) ACPI device power state that the
- * device can be in while the system is in the sleep state represented
- * by %acpi_target_sleep_state.  If @d_min_p is set, the highest power (lowest
- * number) device power state that @dev can be in for the given system sleep
- * state is stored at the location pointed to by it.
- *
  * The caller must ensure that @dev is valid before using this function.
  */
 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
 {
 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 	struct acpi_device *adev;
-	char acpi_method[] = "_SxD";
-	unsigned long long d_min, d_max;
-	bool wakeup = false;
 
-	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
-		return -EINVAL;
 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
-		printk(KERN_DEBUG "ACPI handle has no context!\n");
+		dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
 		return -ENODEV;
 	}
-	if (d_max_in > ACPI_STATE_D3_HOT) {
-		enum pm_qos_flags_status stat;
-
-		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
-		if (stat == PM_QOS_FLAGS_ALL)
-			d_max_in = ACPI_STATE_D3_HOT;
-	}
-
-	acpi_method[2] = '0' + acpi_target_sleep_state;
-	/*
-	 * If the sleep state is S0, the lowest limit from ACPI is D3,
-	 * but if the device has _S0W, we will use the value from _S0W
-	 * as the lowest limit from ACPI.  Finally, we will constrain
-	 * the lowest limit with the specified one.
-	 */
-	d_min = ACPI_STATE_D0;
-	d_max = ACPI_STATE_D3;
 
-	/*
-	 * If present, _SxD methods return the minimum D-state (highest power
-	 * state) we can use for the corresponding S-states.  Otherwise, the
-	 * minimum D-state is D0 (ACPI 3.x).
-	 *
-	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
-	 * provided -- that's our fault recovery, we ignore retval.
-	 */
-	if (acpi_target_sleep_state > ACPI_STATE_S0) {
-		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
-		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
-			&& adev->wakeup.sleep_state >= acpi_target_sleep_state;
-	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
-			PM_QOS_FLAGS_NONE) {
-		wakeup = adev->wakeup.flags.valid;
-	}
-
-	/*
-	 * If _PRW says we can wake up the system from the target sleep state,
-	 * the D-state returned by _SxD is sufficient for that (we assume a
-	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
-	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
-	 * can wake the system.  _S0W may be valid, too.
-	 */
-	if (wakeup) {
-		acpi_status status;
-
-		acpi_method[3] = 'W';
-		status = acpi_evaluate_integer(handle, acpi_method, NULL,
-						&d_max);
-		if (ACPI_FAILURE(status)) {
-			if (acpi_target_sleep_state != ACPI_STATE_S0 ||
-			    status != AE_NOT_FOUND)
-				d_max = d_min;
-		} else if (d_max < d_min) {
-			/* Warn the user of the broken DSDT */
-			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
-				acpi_method);
-			/* Sanitize it */
-			d_min = d_max;
-		}
-	}
-
-	if (d_max_in < d_min)
-		return -EINVAL;
-	if (d_min_p)
-		*d_min_p = d_min;
-	/* constrain d_max with specified lowest limit (max number) */
-	if (d_max > d_max_in) {
-		for (d_max = d_max_in; d_max > d_min; d_max--) {
-			if (adev->power.states[d_max].flags.valid)
-				break;
-		}
-	}
-	return d_max;
+	return acpi_device_power_state(dev, adev, acpi_target_sleep_state,
+				       d_max_in, d_min_p);
 }
 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 #endif /* CONFIG_PM */
Index: linux/include/acpi/acpi_bus.h
===================================================================
--- linux.orig/include/acpi/acpi_bus.h
+++ linux/include/acpi/acpi_bus.h
@@ -419,6 +419,8 @@ acpi_status acpi_add_pm_notifier(struct
 				 acpi_notify_handler handler, void *context);
 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
 				    acpi_notify_handler handler);
+int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
+			    u32 target_state, int d_max_in, int *d_min_p);
 int acpi_pm_device_sleep_state(struct device *, int *, int);
 #else
 static inline acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
@@ -432,12 +434,23 @@ static inline acpi_status acpi_remove_pm
 {
 	return AE_SUPPORT;
 }
-static inline int acpi_pm_device_sleep_state(struct device *d, int *p, int m)
+static inline int __acpi_device_power_state(int m, int *p)
 {
 	if (p)
 		*p = ACPI_STATE_D0;
 	return (m >= ACPI_STATE_D0 && m <= ACPI_STATE_D3) ? m : ACPI_STATE_D0;
 }
+static inline int acpi_device_power_state(struct device *dev,
+					  struct acpi_device *adev,
+					  u32 target_state, int d_max_in,
+					  int *d_min_p)
+{
+	return __acpi_device_power_state(d_max_in, d_min_p);
+}
+static inline int acpi_pm_device_sleep_state(struct device *d, int *p, int m)
+{
+	return __acpi_device_power_state(m, p);
+}
 #endif
 
 #ifdef CONFIG_PM_RUNTIME