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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-29 21:46:33 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-29 21:46:33 +0100
commit26ab93438fbacc653c60ea4d148b6ca16919ab1b (patch)
tree7f95470de4a37770b80f510b5fb4e807b494c0ab /drivers/base/power
parentMerge branch 'pm-cpuidle' (diff)
parentPM / OPP: using kfree_rcu() to simplify the code (diff)
downloadlinux-26ab93438fbacc653c60ea4d148b6ca16919ab1b.tar.xz
linux-26ab93438fbacc653c60ea4d148b6ca16919ab1b.zip
Merge branch 'pm-opp'
* pm-opp: PM / OPP: using kfree_rcu() to simplify the code PM / OPP: predictable fail results for opp_find* functions, v2 PM / OPP: Export symbols for module usage. PM / OPP: RCU reclaim
Diffstat (limited to 'drivers/base/power')
-rw-r--r--drivers/base/power/opp.c44
1 files changed, 31 insertions, 13 deletions
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index d9468642fc41..50b2831e027d 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -23,6 +23,7 @@
#include <linux/rcupdate.h>
#include <linux/opp.h>
#include <linux/of.h>
+#include <linux/export.h>
/*
* Internal data structure organization with the OPP layer library is as
@@ -65,6 +66,7 @@ struct opp {
unsigned long u_volt;
struct device_opp *dev_opp;
+ struct rcu_head head;
};
/**
@@ -160,6 +162,7 @@ unsigned long opp_get_voltage(struct opp *opp)
return v;
}
+EXPORT_SYMBOL(opp_get_voltage);
/**
* opp_get_freq() - Gets the frequency corresponding to an available opp
@@ -189,6 +192,7 @@ unsigned long opp_get_freq(struct opp *opp)
return f;
}
+EXPORT_SYMBOL(opp_get_freq);
/**
* opp_get_opp_count() - Get number of opps available in the opp list
@@ -221,6 +225,7 @@ int opp_get_opp_count(struct device *dev)
return count;
}
+EXPORT_SYMBOL(opp_get_opp_count);
/**
* opp_find_freq_exact() - search for an exact frequency
@@ -230,7 +235,10 @@ int opp_get_opp_count(struct device *dev)
*
* Searches for exact match in the opp list and returns pointer to the matching
* opp if found, else returns ERR_PTR in case of error and should be handled
- * using IS_ERR.
+ * using IS_ERR. Error return values can be:
+ * EINVAL: for bad pointer
+ * ERANGE: no match found for search
+ * ENODEV: if device not found in list of registered devices
*
* Note: available is a modifier for the search. if available=true, then the
* match is for exact matching frequency and is available in the stored OPP
@@ -249,7 +257,7 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq,
bool available)
{
struct device_opp *dev_opp;
- struct opp *temp_opp, *opp = ERR_PTR(-ENODEV);
+ struct opp *temp_opp, *opp = ERR_PTR(-ERANGE);
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
@@ -268,6 +276,7 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq,
return opp;
}
+EXPORT_SYMBOL(opp_find_freq_exact);
/**
* opp_find_freq_ceil() - Search for an rounded ceil freq
@@ -278,7 +287,11 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq,
* for a device.
*
* Returns matching *opp and refreshes *freq accordingly, else returns
- * ERR_PTR in case of error and should be handled using IS_ERR.
+ * ERR_PTR in case of error and should be handled using IS_ERR. Error return
+ * values can be:
+ * EINVAL: for bad pointer
+ * ERANGE: no match found for search
+ * ENODEV: if device not found in list of registered devices
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
@@ -289,7 +302,7 @@ struct opp *opp_find_freq_exact(struct device *dev, unsigned long freq,
struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq)
{
struct device_opp *dev_opp;
- struct opp *temp_opp, *opp = ERR_PTR(-ENODEV);
+ struct opp *temp_opp, *opp = ERR_PTR(-ERANGE);
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
@@ -298,7 +311,7 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq)
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp))
- return opp;
+ return ERR_CAST(dev_opp);
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
if (temp_opp->available && temp_opp->rate >= *freq) {
@@ -310,6 +323,7 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq)
return opp;
}
+EXPORT_SYMBOL(opp_find_freq_ceil);
/**
* opp_find_freq_floor() - Search for a rounded floor freq
@@ -320,7 +334,11 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq)
* for a device.
*
* Returns matching *opp and refreshes *freq accordingly, else returns
- * ERR_PTR in case of error and should be handled using IS_ERR.
+ * ERR_PTR in case of error and should be handled using IS_ERR. Error return
+ * values can be:
+ * EINVAL: for bad pointer
+ * ERANGE: no match found for search
+ * ENODEV: if device not found in list of registered devices
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
@@ -331,7 +349,7 @@ struct opp *opp_find_freq_ceil(struct device *dev, unsigned long *freq)
struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq)
{
struct device_opp *dev_opp;
- struct opp *temp_opp, *opp = ERR_PTR(-ENODEV);
+ struct opp *temp_opp, *opp = ERR_PTR(-ERANGE);
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
@@ -340,7 +358,7 @@ struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq)
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp))
- return opp;
+ return ERR_CAST(dev_opp);
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
if (temp_opp->available) {
@@ -356,6 +374,7 @@ struct opp *opp_find_freq_floor(struct device *dev, unsigned long *freq)
return opp;
}
+EXPORT_SYMBOL(opp_find_freq_floor);
/**
* opp_add() - Add an OPP table from a table definitions
@@ -512,7 +531,7 @@ static int opp_set_availability(struct device *dev, unsigned long freq,
list_replace_rcu(&opp->node, &new_opp->node);
mutex_unlock(&dev_opp_list_lock);
- synchronize_rcu();
+ kfree_rcu(opp, head);
/* Notify the change of the OPP availability */
if (availability_req)
@@ -522,13 +541,10 @@ static int opp_set_availability(struct device *dev, unsigned long freq,
srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE,
new_opp);
- /* clean up old opp */
- new_opp = opp;
- goto out;
+ return 0;
unlock:
mutex_unlock(&dev_opp_list_lock);
-out:
kfree(new_opp);
return r;
}
@@ -552,6 +568,7 @@ int opp_enable(struct device *dev, unsigned long freq)
{
return opp_set_availability(dev, freq, true);
}
+EXPORT_SYMBOL(opp_enable);
/**
* opp_disable() - Disable a specific OPP
@@ -573,6 +590,7 @@ int opp_disable(struct device *dev, unsigned long freq)
{
return opp_set_availability(dev, freq, false);
}
+EXPORT_SYMBOL(opp_disable);
#ifdef CONFIG_CPU_FREQ
/**