Merge branch 'acpi-pm'

* acpi-pm:
  ACPI / PM: Rework and clean up acpi_dev_pm_get_state()
  ACPI / PM: Replace ACPI_STATE_D3 with ACPI_STATE_D3_COLD in device_pm.c
  ACPI / PM: Rename function acpi_device_power_state() and make it static
  ACPI / PM: acpi_processor_suspend() can be static
  xen / ACPI / sleep: Register an acpi_suspend_lowlevel callback.
  x86 / ACPI / sleep: Provide registration for acpi_suspend_lowlevel.

3 files changed, 99 insertions, 72 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 31c217a42839..5f3597b87f27 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -419,62 +419,73 @@ bool acpi_bus_can_wakeup(acpi_handle handle)
 EXPORT_SYMBOL(acpi_bus_can_wakeup);
 
 /**
- * acpi_device_power_state - Get preferred power state of ACPI device.
+ * acpi_dev_pm_get_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
+ * @d_min_p: Location to store the highest power state available to the device.
+ * @d_max_p: Location to store the lowest power state available to the device.
  *
- * 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.
+ * Find the lowest power (highest number) and highest power (lowest number) ACPI
+ * device power states that the device can be in while the system is in the
+ * state represented by @target_state.  Store the integer numbers representing
+ * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
+ * respectively.
  *
  * Callers must ensure that @dev and @adev are valid pointers and that @adev
  * actually corresponds to @dev before using this function.
+ *
+ * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
+ * returns a value that doesn't make sense.  The memory locations pointed to by
+ * @d_max_p and @d_min_p are only modified on success.
  */
-int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
-                            u32 target_state, int d_max_in, int *d_min_p)
+static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
+                                 u32 target_state, int *d_min_p, int *d_max_p)
 {
-        char acpi_method[] = "_SxD";
-        unsigned long long d_min, d_max;
+        char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
+        acpi_handle handle = adev->handle;
+        unsigned long long ret;
+        int d_min, d_max;
         bool wakeup = false;
+        acpi_status status;
 
-        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.
+         * If the system state is S0, the lowest power state the device can be
+         * in is D3cold, unless the device has _S0W and is supposed to signal
+         * wakeup, in which case the return value of _S0W has to be used as the
+         * lowest power state available to the device.
          */
         d_min = ACPI_STATE_D0;
-        d_max = ACPI_STATE_D3;
+        d_max = ACPI_STATE_D3_COLD;
 
         /*
          * 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);
+                /*
+                 * We rely on acpi_evaluate_integer() not clobbering the integer
+                 * provided if AE_NOT_FOUND is returned.
+                 */
+                ret = d_min;
+                status = acpi_evaluate_integer(handle, method, NULL, &ret);
+                if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
+                    || ret > ACPI_STATE_D3_COLD)
+                        return -ENODATA;
+
+                /*
+                 * We need to handle legacy systems where D3hot and D3cold are
+                 * the same and 3 is returned in both cases, so fall back to
+                 * D3cold if D3hot is not a valid state.
+                 */
+                if (!adev->power.states[ret].flags.valid) {
+                        if (ret == ACPI_STATE_D3_HOT)
+                                ret = ACPI_STATE_D3_COLD;
+                        else
+                                return -ENODATA;
+                }
+                d_min = ret;
                 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) !=
@@ -490,38 +501,30 @@ int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
          * 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)
+                method[3] = 'W';
+                status = acpi_evaluate_integer(handle, method, NULL, &ret);
+                if (status == AE_NOT_FOUND) {
+                        if (target_state > ACPI_STATE_S0)
                                 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;
+                } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
+                        /* Fall back to D3cold if ret is not a valid state. */
+                        if (!adev->power.states[ret].flags.valid)
+                                ret = ACPI_STATE_D3_COLD;
+
+                        d_max = ret > d_min ? ret : d_min;
+                } else {
+                        return -ENODATA;
                 }
         }
 
-        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;
+
+        if (d_max_p)
+                *d_max_p = d_max;
+
+        return 0;
 }
-EXPORT_SYMBOL_GPL(acpi_device_power_state);
 
 /**
  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
@@ -529,7 +532,8 @@ EXPORT_SYMBOL_GPL(acpi_device_power_state);
  * @d_min_p: Location to store the upper limit of the allowed states range.
  * @d_max_in: Deepest low-power state to take into consideration.
  * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
+ * incorrect, or -ENODATA on ACPI method failure.
  *
  * The caller must ensure that @dev is valid before using this function.
  */
@@ -537,14 +541,39 @@ 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;
+        int ret, d_max;
+
+        if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
+                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;
+        }
 
         if (!handle || acpi_bus_get_device(handle, &adev)) {
                 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
                 return -ENODEV;
         }
 
-        return acpi_device_power_state(dev, adev, acpi_target_system_state(),
-                                       d_max_in, d_min_p);
+        ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
+                                    d_min_p, &d_max);
+        if (ret)
+                return ret;
+
+        if (d_max_in < *d_min_p)
+                return -EINVAL;
+
+        if (d_max > d_max_in) {
+                for (d_max = d_max_in; d_max > *d_min_p; d_max--) {
+                        if (adev->power.states[d_max].flags.valid)
+                                break;
+                }
+        }
+        return d_max;
 }
 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
@@ -695,17 +724,13 @@ struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
                                  u32 system_state)
 {
-        int power_state;
+        int ret, state;
 
         if (!acpi_device_power_manageable(adev))
                 return 0;
 
-        power_state = acpi_device_power_state(dev, adev, system_state,
-                                              ACPI_STATE_D3, NULL);
-        if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3)
-                return -EIO;
-
-        return acpi_device_set_power(adev, power_state);
+        ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
+        return ret ? ret : acpi_device_set_power(adev, state);
 }
 
 /**
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index eb133c77aadb..0461ccc92c54 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -214,13 +214,13 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 #ifdef CONFIG_PM_SLEEP
 static u32 saved_bm_rld;
 
-int acpi_processor_suspend(void)
+static int acpi_processor_suspend(void)
 {
         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
         return 0;
 }
 
-void acpi_processor_resume(void)
+static void acpi_processor_resume(void)
 {
         u32 resumed_bm_rld;
 
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 9c1a435d10e6..187ab61889e6 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -494,6 +494,8 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
                 break;
 
         case ACPI_STATE_S3:
+                if (!acpi_suspend_lowlevel)
+                        return -ENOSYS;
                 error = acpi_suspend_lowlevel();
                 if (error)
                         return error;