Skip to content

Commit

Permalink
Merge branch 'pm-opp'
Browse files Browse the repository at this point in the history 
* 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
  • Loading branch information
Rafael J. Wysocki committed Nov 29, 2012
2 parents 9ee71f5 + ea83f81 commit 26ab934
Show file tree
Hide file tree
Showing 2 changed files with 33 additions and 15 deletions.
44 changes: 31 additions & 13 deletions drivers/base/power/opp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -65,6 +66,7 @@ struct opp {
unsigned long u_volt;

struct device_opp *dev_opp;
struct rcu_head head;
};

/**
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand All @@ -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
Expand All @@ -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)) {
Expand All @@ -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
Expand All @@ -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
Expand All @@ -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);
Expand All @@ -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) {
Expand All @@ -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
Expand All @@ -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
Expand All @@ -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);
Expand All @@ -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) {
Expand All @@ -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
Expand Down Expand Up @@ -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)
Expand All @@ -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;
}
Expand All @@ -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
Expand All @@ -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
/**
Expand Down
4 changes: 2 additions & 2 deletions drivers/devfreq/devfreq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -656,14 +656,14 @@ struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
opp = opp_find_freq_floor(dev, freq);

/* If not available, use the closest opp */
if (opp == ERR_PTR(-ENODEV))
if (opp == ERR_PTR(-ERANGE))
opp = opp_find_freq_ceil(dev, freq);
} else {
/* The freq is an lower bound. opp should be higher */
opp = opp_find_freq_ceil(dev, freq);

/* If not available, use the closest opp */
if (opp == ERR_PTR(-ENODEV))
if (opp == ERR_PTR(-ERANGE))
opp = opp_find_freq_floor(dev, freq);
}

Expand Down

0 comments on commit 26ab934

Please sign in to comment.