Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...

1 files changed, 44 insertions, 34 deletions

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 2d195f3a1998..d24dd614a0bd 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -84,7 +84,11 @@ struct dev_pm_opp {
  *
  * This is an internal data structure maintaining the link to opps attached to
  * a device. This structure is not meant to be shared to users as it is
- * meant for book keeping and private to OPP library
+ * meant for book keeping and private to OPP library.
+ *
+ * Because the opp structures can be used from both rcu and srcu readers, we
+ * need to wait for the grace period of both of them before freeing any
+ * resources. And so we have used kfree_rcu() from within call_srcu() handlers.
  */
 struct device_opp {
         struct list_head node;
@@ -382,12 +386,34 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
+static struct device_opp *add_device_opp(struct device *dev)
+{
+        struct device_opp *dev_opp;
+
+        /*
+         * Allocate a new device OPP table. In the infrequent case where a new
+         * device is needed to be added, we pay this penalty.
+         */
+        dev_opp = kzalloc(sizeof(*dev_opp), GFP_KERNEL);
+        if (!dev_opp)
+                return NULL;
+
+        dev_opp->dev = dev;
+        srcu_init_notifier_head(&dev_opp->srcu_head);
+        INIT_LIST_HEAD(&dev_opp->opp_list);
+
+        /* Secure the device list modification */
+        list_add_rcu(&dev_opp->node, &dev_opp_list);
+        return dev_opp;
+}
+
 static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq,
                                   unsigned long u_volt, bool dynamic)
 {
         struct device_opp *dev_opp = NULL;
         struct dev_pm_opp *opp, *new_opp;
         struct list_head *head;
+        int ret;
 
         /* allocate new OPP node */
         new_opp = kzalloc(sizeof(*new_opp), GFP_KERNEL);
@@ -400,7 +426,6 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq,
         mutex_lock(&dev_opp_list_lock);
 
         /* populate the opp table */
-        new_opp->dev_opp = dev_opp;
         new_opp->rate = freq;
         new_opp->u_volt = u_volt;
         new_opp->available = true;
@@ -409,27 +434,12 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq,
         /* Check for existing list for 'dev' */
         dev_opp = find_device_opp(dev);
         if (IS_ERR(dev_opp)) {
-                /*
-                 * Allocate a new device OPP table. In the infrequent case
-                 * where a new device is needed to be added, we pay this
-                 * penalty.
-                 */
-                dev_opp = kzalloc(sizeof(struct device_opp), GFP_KERNEL);
+                dev_opp = add_device_opp(dev);
                 if (!dev_opp) {
-                        mutex_unlock(&dev_opp_list_lock);
-                        kfree(new_opp);
-                        dev_warn(dev,
-                                "%s: Unable to create device OPP structure\n",
-                                __func__);
-                        return -ENOMEM;
+                        ret = -ENOMEM;
+                        goto free_opp;
                 }
 
-                dev_opp->dev = dev;
-                srcu_init_notifier_head(&dev_opp->srcu_head);
-                INIT_LIST_HEAD(&dev_opp->opp_list);
-
-                /* Secure the device list modification */
-                list_add_rcu(&dev_opp->node, &dev_opp_list);
                 head = &dev_opp->opp_list;
                 goto list_add;
         }
@@ -448,18 +458,17 @@ static int dev_pm_opp_add_dynamic(struct device *dev, unsigned long freq,
 
         /* Duplicate OPPs ? */
         if (new_opp->rate == opp->rate) {
-                int ret = opp->available && new_opp->u_volt == opp->u_volt ?
+                ret = opp->available && new_opp->u_volt == opp->u_volt ?
                         0 : -EEXIST;
 
                 dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
                          __func__, opp->rate, opp->u_volt, opp->available,
                          new_opp->rate, new_opp->u_volt, new_opp->available);
-                mutex_unlock(&dev_opp_list_lock);
-                kfree(new_opp);
-                return ret;
+                goto free_opp;
         }
 
 list_add:
+        new_opp->dev_opp = dev_opp;
         list_add_rcu(&new_opp->node, head);
         mutex_unlock(&dev_opp_list_lock);
 
@@ -469,6 +478,11 @@ list_add:
          */
         srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADD, new_opp);
         return 0;
+
+free_opp:
+        mutex_unlock(&dev_opp_list_lock);
+        kfree(new_opp);
+        return ret;
 }
 
 /**
@@ -511,10 +525,11 @@ static void kfree_device_rcu(struct rcu_head *head)
 {
         struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
 
-        kfree(device_opp);
+        kfree_rcu(device_opp, rcu_head);
 }
 
-void __dev_pm_opp_remove(struct device_opp *dev_opp, struct dev_pm_opp *opp)
+static void __dev_pm_opp_remove(struct device_opp *dev_opp,
+                                struct dev_pm_opp *opp)
 {
         /*
          * Notify the changes in the availability of the operable
@@ -592,7 +607,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 static int opp_set_availability(struct device *dev, unsigned long freq,
                 bool availability_req)
 {
-        struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV);
+        struct device_opp *dev_opp;
         struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV);
         int r = 0;
 
@@ -606,12 +621,7 @@ static int opp_set_availability(struct device *dev, unsigned long freq,
         mutex_lock(&dev_opp_list_lock);
 
         /* Find the device_opp */
-        list_for_each_entry(tmp_dev_opp, &dev_opp_list, node) {
-                if (dev == tmp_dev_opp->dev) {
-                        dev_opp = tmp_dev_opp;
-                        break;
-                }
-        }
+        dev_opp = find_device_opp(dev);
         if (IS_ERR(dev_opp)) {
                 r = PTR_ERR(dev_opp);
                 dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
@@ -768,7 +778,7 @@ EXPORT_SYMBOL_GPL(of_init_opp_table);
  */
 void of_free_opp_table(struct device *dev)
 {
-        struct device_opp *dev_opp = find_device_opp(dev);
+        struct device_opp *dev_opp;
         struct dev_pm_opp *opp, *tmp;
 
         /* Check for existing list for 'dev' */