ACPI / PM: Move device power state selection routine to device_pm.c

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>

3 files changed, 124 insertions, 86 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 2d2e0bc8891b..c017b801171c 100644
--- a/drivers/acpi/device_pm.c
+++ b/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(struct acpi_device *adev,
         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);
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 4defa0297ee4..fa20d0171887 100644
--- a/drivers/acpi/sleep.c
+++ b/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>
 
@@ -691,101 +690,20 @@ 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 */
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 6983272f9d02..a8080dfe7183 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -420,6 +420,8 @@ acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
                                  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,
@@ -433,12 +435,23 @@ static inline acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
 {
         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