![Quentin Lambert](/assets/img/avatar_default.png)
This patch reduces the kernel size by removing error messages that duplicate the normal OOM message. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr) @@ identifier f,print,l; expression e; constant char[] c; @@ e = \(kzalloc\|kmalloc\|devm_kzalloc\|devm_kmalloc\)(...); if (e == NULL) { <+... - print(...,c,...); ... when any ( goto l; | return ...; ) ...+> } Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com> Acked-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
928 lines
28 KiB
C
928 lines
28 KiB
C
/*
|
|
* Generic OPP Interface
|
|
*
|
|
* Copyright (C) 2009-2010 Texas Instruments Incorporated.
|
|
* Nishanth Menon
|
|
* Romit Dasgupta
|
|
* Kevin Hilman
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/device.h>
|
|
#include <linux/list.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/pm_opp.h>
|
|
#include <linux/of.h>
|
|
#include <linux/export.h>
|
|
|
|
/*
|
|
* Internal data structure organization with the OPP layer library is as
|
|
* follows:
|
|
* dev_opp_list (root)
|
|
* |- device 1 (represents voltage domain 1)
|
|
* | |- opp 1 (availability, freq, voltage)
|
|
* | |- opp 2 ..
|
|
* ... ...
|
|
* | `- opp n ..
|
|
* |- device 2 (represents the next voltage domain)
|
|
* ...
|
|
* `- device m (represents mth voltage domain)
|
|
* device 1, 2.. are represented by dev_opp structure while each opp
|
|
* is represented by the opp structure.
|
|
*/
|
|
|
|
/**
|
|
* struct dev_pm_opp - Generic OPP description structure
|
|
* @node: opp list node. The nodes are maintained throughout the lifetime
|
|
* of boot. It is expected only an optimal set of OPPs are
|
|
* added to the library by the SoC framework.
|
|
* RCU usage: opp list is traversed with RCU locks. node
|
|
* modification is possible realtime, hence the modifications
|
|
* are protected by the dev_opp_list_lock for integrity.
|
|
* IMPORTANT: the opp nodes should be maintained in increasing
|
|
* order.
|
|
* @dynamic: not-created from static DT entries.
|
|
* @available: true/false - marks if this OPP as available or not
|
|
* @rate: Frequency in hertz
|
|
* @u_volt: Nominal voltage in microvolts corresponding to this OPP
|
|
* @dev_opp: points back to the device_opp struct this opp belongs to
|
|
* @rcu_head: RCU callback head used for deferred freeing
|
|
*
|
|
* This structure stores the OPP information for a given device.
|
|
*/
|
|
struct dev_pm_opp {
|
|
struct list_head node;
|
|
|
|
bool available;
|
|
bool dynamic;
|
|
unsigned long rate;
|
|
unsigned long u_volt;
|
|
|
|
struct device_opp *dev_opp;
|
|
struct rcu_head rcu_head;
|
|
};
|
|
|
|
/**
|
|
* struct device_opp - Device opp structure
|
|
* @node: list node - contains the devices with OPPs that
|
|
* have been registered. Nodes once added are not modified in this
|
|
* list.
|
|
* RCU usage: nodes are not modified in the list of device_opp,
|
|
* however addition is possible and is secured by dev_opp_list_lock
|
|
* @dev: device pointer
|
|
* @srcu_head: notifier head to notify the OPP availability changes.
|
|
* @rcu_head: RCU callback head used for deferred freeing
|
|
* @opp_list: list of opps
|
|
*
|
|
* 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.
|
|
*
|
|
* 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;
|
|
|
|
struct device *dev;
|
|
struct srcu_notifier_head srcu_head;
|
|
struct rcu_head rcu_head;
|
|
struct list_head opp_list;
|
|
};
|
|
|
|
/*
|
|
* The root of the list of all devices. All device_opp structures branch off
|
|
* from here, with each device_opp containing the list of opp it supports in
|
|
* various states of availability.
|
|
*/
|
|
static LIST_HEAD(dev_opp_list);
|
|
/* Lock to allow exclusive modification to the device and opp lists */
|
|
static DEFINE_MUTEX(dev_opp_list_lock);
|
|
|
|
#define opp_rcu_lockdep_assert() \
|
|
do { \
|
|
rcu_lockdep_assert(rcu_read_lock_held() || \
|
|
lockdep_is_held(&dev_opp_list_lock), \
|
|
"Missing rcu_read_lock() or " \
|
|
"dev_opp_list_lock protection"); \
|
|
} while (0)
|
|
|
|
/**
|
|
* _find_device_opp() - find device_opp struct using device pointer
|
|
* @dev: device pointer used to lookup device OPPs
|
|
*
|
|
* Search list of device OPPs for one containing matching device. Does a RCU
|
|
* reader operation to grab the pointer needed.
|
|
*
|
|
* Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or
|
|
* -EINVAL based on type of error.
|
|
*
|
|
* Locking: This function must be called under rcu_read_lock(). device_opp
|
|
* is a RCU protected pointer. This means that device_opp is valid as long
|
|
* as we are under RCU lock.
|
|
*/
|
|
static struct device_opp *_find_device_opp(struct device *dev)
|
|
{
|
|
struct device_opp *tmp_dev_opp, *dev_opp = ERR_PTR(-ENODEV);
|
|
|
|
if (unlikely(IS_ERR_OR_NULL(dev))) {
|
|
pr_err("%s: Invalid parameters\n", __func__);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
list_for_each_entry_rcu(tmp_dev_opp, &dev_opp_list, node) {
|
|
if (tmp_dev_opp->dev == dev) {
|
|
dev_opp = tmp_dev_opp;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return dev_opp;
|
|
}
|
|
|
|
/**
|
|
* dev_pm_opp_get_voltage() - Gets the voltage corresponding to an available opp
|
|
* @opp: opp for which voltage has to be returned for
|
|
*
|
|
* Return: voltage in micro volt corresponding to the opp, else
|
|
* return 0
|
|
*
|
|
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
|
|
* protected pointer. This means that opp which could have been fetched by
|
|
* opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
|
|
* under RCU lock. The pointer returned by the opp_find_freq family must be
|
|
* used in the same section as the usage of this function with the pointer
|
|
* prior to unlocking with rcu_read_unlock() to maintain the integrity of the
|
|
* pointer.
|
|
*/
|
|
unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
|
|
{
|
|
struct dev_pm_opp *tmp_opp;
|
|
unsigned long v = 0;
|
|
|
|
opp_rcu_lockdep_assert();
|
|
|
|
tmp_opp = rcu_dereference(opp);
|
|
if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available)
|
|
pr_err("%s: Invalid parameters\n", __func__);
|
|
else
|
|
v = tmp_opp->u_volt;
|
|
|
|
return v;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
|
|
|
|
/**
|
|
* dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
|
|
* @opp: opp for which frequency has to be returned for
|
|
*
|
|
* Return: frequency in hertz corresponding to the opp, else
|
|
* return 0
|
|
*
|
|
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
|
|
* protected pointer. This means that opp which could have been fetched by
|
|
* opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
|
|
* under RCU lock. The pointer returned by the opp_find_freq family must be
|
|
* used in the same section as the usage of this function with the pointer
|
|
* prior to unlocking with rcu_read_unlock() to maintain the integrity of the
|
|
* pointer.
|
|
*/
|
|
unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
|
|
{
|
|
struct dev_pm_opp *tmp_opp;
|
|
unsigned long f = 0;
|
|
|
|
opp_rcu_lockdep_assert();
|
|
|
|
tmp_opp = rcu_dereference(opp);
|
|
if (unlikely(IS_ERR_OR_NULL(tmp_opp)) || !tmp_opp->available)
|
|
pr_err("%s: Invalid parameters\n", __func__);
|
|
else
|
|
f = tmp_opp->rate;
|
|
|
|
return f;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
|
|
|
|
/**
|
|
* dev_pm_opp_get_opp_count() - Get number of opps available in the opp list
|
|
* @dev: device for which we do this operation
|
|
*
|
|
* Return: This function returns the number of available opps if there are any,
|
|
* else returns 0 if none or the corresponding error value.
|
|
*
|
|
* Locking: This function takes rcu_read_lock().
|
|
*/
|
|
int dev_pm_opp_get_opp_count(struct device *dev)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *temp_opp;
|
|
int count = 0;
|
|
|
|
rcu_read_lock();
|
|
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp)) {
|
|
count = PTR_ERR(dev_opp);
|
|
dev_err(dev, "%s: device OPP not found (%d)\n",
|
|
__func__, count);
|
|
goto out_unlock;
|
|
}
|
|
|
|
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
|
|
if (temp_opp->available)
|
|
count++;
|
|
}
|
|
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
|
|
|
|
/**
|
|
* dev_pm_opp_find_freq_exact() - search for an exact frequency
|
|
* @dev: device for which we do this operation
|
|
* @freq: frequency to search for
|
|
* @available: true/false - match for available opp
|
|
*
|
|
* Return: 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. 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
|
|
* table. if false, the match is for exact frequency which is not available.
|
|
*
|
|
* This provides a mechanism to enable an opp which is not available currently
|
|
* or the opposite as well.
|
|
*
|
|
* 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
|
|
* returned will remain valid for use with opp_get_{voltage, freq} only while
|
|
* under the locked area. The pointer returned must be used prior to unlocking
|
|
* with rcu_read_unlock() to maintain the integrity of the pointer.
|
|
*/
|
|
struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
|
|
unsigned long freq,
|
|
bool available)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
|
|
|
|
opp_rcu_lockdep_assert();
|
|
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp)) {
|
|
int r = PTR_ERR(dev_opp);
|
|
dev_err(dev, "%s: device OPP not found (%d)\n", __func__, r);
|
|
return ERR_PTR(r);
|
|
}
|
|
|
|
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
|
|
if (temp_opp->available == available &&
|
|
temp_opp->rate == freq) {
|
|
opp = temp_opp;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return opp;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
|
|
|
|
/**
|
|
* dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
|
|
* @dev: device for which we do this operation
|
|
* @freq: Start frequency
|
|
*
|
|
* Search for the matching ceil *available* OPP from a starting freq
|
|
* for a device.
|
|
*
|
|
* Return: matching *opp and refreshes *freq accordingly, else returns
|
|
* 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
|
|
* returned will remain valid for use with opp_get_{voltage, freq} only while
|
|
* under the locked area. The pointer returned must be used prior to unlocking
|
|
* with rcu_read_unlock() to maintain the integrity of the pointer.
|
|
*/
|
|
struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
|
|
unsigned long *freq)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
|
|
|
|
opp_rcu_lockdep_assert();
|
|
|
|
if (!dev || !freq) {
|
|
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_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) {
|
|
opp = temp_opp;
|
|
*freq = opp->rate;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return opp;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
|
|
|
|
/**
|
|
* dev_pm_opp_find_freq_floor() - Search for a rounded floor freq
|
|
* @dev: device for which we do this operation
|
|
* @freq: Start frequency
|
|
*
|
|
* Search for the matching floor *available* OPP from a starting freq
|
|
* for a device.
|
|
*
|
|
* Return: matching *opp and refreshes *freq accordingly, else returns
|
|
* 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
|
|
* returned will remain valid for use with opp_get_{voltage, freq} only while
|
|
* under the locked area. The pointer returned must be used prior to unlocking
|
|
* with rcu_read_unlock() to maintain the integrity of the pointer.
|
|
*/
|
|
struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
|
|
unsigned long *freq)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
|
|
|
|
opp_rcu_lockdep_assert();
|
|
|
|
if (!dev || !freq) {
|
|
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp))
|
|
return ERR_CAST(dev_opp);
|
|
|
|
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
|
|
if (temp_opp->available) {
|
|
/* go to the next node, before choosing prev */
|
|
if (temp_opp->rate > *freq)
|
|
break;
|
|
else
|
|
opp = temp_opp;
|
|
}
|
|
}
|
|
if (!IS_ERR(opp))
|
|
*freq = opp->rate;
|
|
|
|
return opp;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
|
|
|
|
/**
|
|
* _add_device_opp() - Allocate a new device OPP table
|
|
* @dev: device for which we do this operation
|
|
*
|
|
* New device node which uses OPPs - used when multiple devices with OPP tables
|
|
* are maintained.
|
|
*
|
|
* Return: valid device_opp pointer if success, else NULL.
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* _opp_add_dynamic() - Allocate a dynamic OPP.
|
|
* @dev: device for which we do this operation
|
|
* @freq: Frequency in Hz for this OPP
|
|
* @u_volt: Voltage in uVolts for this OPP
|
|
* @dynamic: Dynamically added OPPs.
|
|
*
|
|
* This function adds an opp definition to the opp list and returns status.
|
|
* The opp is made available by default and it can be controlled using
|
|
* dev_pm_opp_enable/disable functions and may be removed by dev_pm_opp_remove.
|
|
*
|
|
* NOTE: "dynamic" parameter impacts OPPs added by the of_init_opp_table and
|
|
* freed by of_free_opp_table.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function internally uses RCU updater strategy with mutex locks
|
|
* to keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex cannot be locked.
|
|
*
|
|
* Return:
|
|
* 0 On success OR
|
|
* Duplicate OPPs (both freq and volt are same) and opp->available
|
|
* -EEXIST Freq are same and volt are different OR
|
|
* Duplicate OPPs (both freq and volt are same) and !opp->available
|
|
* -ENOMEM Memory allocation failure
|
|
*/
|
|
static int _opp_add_dynamic(struct device *dev, unsigned long freq,
|
|
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);
|
|
if (!new_opp)
|
|
return -ENOMEM;
|
|
|
|
/* Hold our list modification lock here */
|
|
mutex_lock(&dev_opp_list_lock);
|
|
|
|
/* populate the opp table */
|
|
new_opp->rate = freq;
|
|
new_opp->u_volt = u_volt;
|
|
new_opp->available = true;
|
|
new_opp->dynamic = dynamic;
|
|
|
|
/* Check for existing list for 'dev' */
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp)) {
|
|
dev_opp = _add_device_opp(dev);
|
|
if (!dev_opp) {
|
|
ret = -ENOMEM;
|
|
goto free_opp;
|
|
}
|
|
|
|
head = &dev_opp->opp_list;
|
|
goto list_add;
|
|
}
|
|
|
|
/*
|
|
* Insert new OPP in order of increasing frequency
|
|
* and discard if already present
|
|
*/
|
|
head = &dev_opp->opp_list;
|
|
list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
|
|
if (new_opp->rate <= opp->rate)
|
|
break;
|
|
else
|
|
head = &opp->node;
|
|
}
|
|
|
|
/* Duplicate OPPs ? */
|
|
if (new_opp->rate == opp->rate) {
|
|
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);
|
|
goto free_opp;
|
|
}
|
|
|
|
list_add:
|
|
new_opp->dev_opp = dev_opp;
|
|
list_add_rcu(&new_opp->node, head);
|
|
mutex_unlock(&dev_opp_list_lock);
|
|
|
|
/*
|
|
* Notify the changes in the availability of the operable
|
|
* frequency/voltage list.
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* dev_pm_opp_add() - Add an OPP table from a table definitions
|
|
* @dev: device for which we do this operation
|
|
* @freq: Frequency in Hz for this OPP
|
|
* @u_volt: Voltage in uVolts for this OPP
|
|
*
|
|
* This function adds an opp definition to the opp list and returns status.
|
|
* The opp is made available by default and it can be controlled using
|
|
* dev_pm_opp_enable/disable functions.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function internally uses RCU updater strategy with mutex locks
|
|
* to keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex cannot be locked.
|
|
*
|
|
* Return:
|
|
* 0 On success OR
|
|
* Duplicate OPPs (both freq and volt are same) and opp->available
|
|
* -EEXIST Freq are same and volt are different OR
|
|
* Duplicate OPPs (both freq and volt are same) and !opp->available
|
|
* -ENOMEM Memory allocation failure
|
|
*/
|
|
int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
|
|
{
|
|
return _opp_add_dynamic(dev, freq, u_volt, true);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_add);
|
|
|
|
/**
|
|
* _kfree_opp_rcu() - Free OPP RCU handler
|
|
* @head: RCU head
|
|
*/
|
|
static void _kfree_opp_rcu(struct rcu_head *head)
|
|
{
|
|
struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
|
|
|
|
kfree_rcu(opp, rcu_head);
|
|
}
|
|
|
|
/**
|
|
* _kfree_device_rcu() - Free device_opp RCU handler
|
|
* @head: RCU head
|
|
*/
|
|
static void _kfree_device_rcu(struct rcu_head *head)
|
|
{
|
|
struct device_opp *device_opp = container_of(head, struct device_opp, rcu_head);
|
|
|
|
kfree_rcu(device_opp, rcu_head);
|
|
}
|
|
|
|
/**
|
|
* _opp_remove() - Remove an OPP from a table definition
|
|
* @dev_opp: points back to the device_opp struct this opp belongs to
|
|
* @opp: pointer to the OPP to remove
|
|
*
|
|
* This function removes an opp definition from the opp list.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* It is assumed that the caller holds required mutex for an RCU updater
|
|
* strategy.
|
|
*/
|
|
static void _opp_remove(struct device_opp *dev_opp,
|
|
struct dev_pm_opp *opp)
|
|
{
|
|
/*
|
|
* Notify the changes in the availability of the operable
|
|
* frequency/voltage list.
|
|
*/
|
|
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
|
|
list_del_rcu(&opp->node);
|
|
call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
|
|
|
|
if (list_empty(&dev_opp->opp_list)) {
|
|
list_del_rcu(&dev_opp->node);
|
|
call_srcu(&dev_opp->srcu_head.srcu, &dev_opp->rcu_head,
|
|
_kfree_device_rcu);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* dev_pm_opp_remove() - Remove an OPP from OPP list
|
|
* @dev: device for which we do this operation
|
|
* @freq: OPP to remove with matching 'freq'
|
|
*
|
|
* This function removes an opp from the opp list.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function internally uses RCU updater strategy with mutex locks
|
|
* to keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex cannot be locked.
|
|
*/
|
|
void dev_pm_opp_remove(struct device *dev, unsigned long freq)
|
|
{
|
|
struct dev_pm_opp *opp;
|
|
struct device_opp *dev_opp;
|
|
bool found = false;
|
|
|
|
/* Hold our list modification lock here */
|
|
mutex_lock(&dev_opp_list_lock);
|
|
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp))
|
|
goto unlock;
|
|
|
|
list_for_each_entry(opp, &dev_opp->opp_list, node) {
|
|
if (opp->rate == freq) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
|
|
__func__, freq);
|
|
goto unlock;
|
|
}
|
|
|
|
_opp_remove(dev_opp, opp);
|
|
unlock:
|
|
mutex_unlock(&dev_opp_list_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
|
|
|
|
/**
|
|
* _opp_set_availability() - helper to set the availability of an opp
|
|
* @dev: device for which we do this operation
|
|
* @freq: OPP frequency to modify availability
|
|
* @availability_req: availability status requested for this opp
|
|
*
|
|
* Set the availability of an OPP with an RCU operation, opp_{enable,disable}
|
|
* share a common logic which is isolated here.
|
|
*
|
|
* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
|
|
* copy operation, returns 0 if no modifcation was done OR modification was
|
|
* successful.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function internally uses RCU updater strategy with mutex locks to
|
|
* keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex locking or synchronize_rcu() blocking calls cannot be used.
|
|
*/
|
|
static int _opp_set_availability(struct device *dev, unsigned long freq,
|
|
bool availability_req)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV);
|
|
int r = 0;
|
|
|
|
/* keep the node allocated */
|
|
new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL);
|
|
if (!new_opp)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&dev_opp_list_lock);
|
|
|
|
/* Find the device_opp */
|
|
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);
|
|
goto unlock;
|
|
}
|
|
|
|
/* Do we have the frequency? */
|
|
list_for_each_entry(tmp_opp, &dev_opp->opp_list, node) {
|
|
if (tmp_opp->rate == freq) {
|
|
opp = tmp_opp;
|
|
break;
|
|
}
|
|
}
|
|
if (IS_ERR(opp)) {
|
|
r = PTR_ERR(opp);
|
|
goto unlock;
|
|
}
|
|
|
|
/* Is update really needed? */
|
|
if (opp->available == availability_req)
|
|
goto unlock;
|
|
/* copy the old data over */
|
|
*new_opp = *opp;
|
|
|
|
/* plug in new node */
|
|
new_opp->available = availability_req;
|
|
|
|
list_replace_rcu(&opp->node, &new_opp->node);
|
|
mutex_unlock(&dev_opp_list_lock);
|
|
call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
|
|
|
|
/* Notify the change of the OPP availability */
|
|
if (availability_req)
|
|
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ENABLE,
|
|
new_opp);
|
|
else
|
|
srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_DISABLE,
|
|
new_opp);
|
|
|
|
return 0;
|
|
|
|
unlock:
|
|
mutex_unlock(&dev_opp_list_lock);
|
|
kfree(new_opp);
|
|
return r;
|
|
}
|
|
|
|
/**
|
|
* dev_pm_opp_enable() - Enable a specific OPP
|
|
* @dev: device for which we do this operation
|
|
* @freq: OPP frequency to enable
|
|
*
|
|
* Enables a provided opp. If the operation is valid, this returns 0, else the
|
|
* corresponding error value. It is meant to be used for users an OPP available
|
|
* after being temporarily made unavailable with dev_pm_opp_disable.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function indirectly uses RCU and mutex locks to keep the
|
|
* integrity of the internal data structures. Callers should ensure that
|
|
* this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex locking or synchronize_rcu() blocking calls cannot be used.
|
|
*
|
|
* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
|
|
* copy operation, returns 0 if no modifcation was done OR modification was
|
|
* successful.
|
|
*/
|
|
int dev_pm_opp_enable(struct device *dev, unsigned long freq)
|
|
{
|
|
return _opp_set_availability(dev, freq, true);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_enable);
|
|
|
|
/**
|
|
* dev_pm_opp_disable() - Disable a specific OPP
|
|
* @dev: device for which we do this operation
|
|
* @freq: OPP frequency to disable
|
|
*
|
|
* Disables a provided opp. If the operation is valid, this returns
|
|
* 0, else the corresponding error value. It is meant to be a temporary
|
|
* control by users to make this OPP not available until the circumstances are
|
|
* right to make it available again (with a call to dev_pm_opp_enable).
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function indirectly uses RCU and mutex locks to keep the
|
|
* integrity of the internal data structures. Callers should ensure that
|
|
* this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex locking or synchronize_rcu() blocking calls cannot be used.
|
|
*
|
|
* Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
|
|
* copy operation, returns 0 if no modifcation was done OR modification was
|
|
* successful.
|
|
*/
|
|
int dev_pm_opp_disable(struct device *dev, unsigned long freq)
|
|
{
|
|
return _opp_set_availability(dev, freq, false);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_disable);
|
|
|
|
/**
|
|
* dev_pm_opp_get_notifier() - find notifier_head of the device with opp
|
|
* @dev: device pointer used to lookup device OPPs.
|
|
*
|
|
* Return: pointer to notifier head if found, otherwise -ENODEV or
|
|
* -EINVAL based on type of error casted as pointer. value must be checked
|
|
* with IS_ERR to determine valid pointer or error result.
|
|
*
|
|
* Locking: This function must be called under rcu_read_lock(). dev_opp is a RCU
|
|
* protected pointer. The reason for the same is that the opp pointer which is
|
|
* returned will remain valid for use with opp_get_{voltage, freq} only while
|
|
* under the locked area. The pointer returned must be used prior to unlocking
|
|
* with rcu_read_unlock() to maintain the integrity of the pointer.
|
|
*/
|
|
struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)
|
|
{
|
|
struct device_opp *dev_opp = _find_device_opp(dev);
|
|
|
|
if (IS_ERR(dev_opp))
|
|
return ERR_CAST(dev_opp); /* matching type */
|
|
|
|
return &dev_opp->srcu_head;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);
|
|
|
|
#ifdef CONFIG_OF
|
|
/**
|
|
* of_init_opp_table() - Initialize opp table from device tree
|
|
* @dev: device pointer used to lookup device OPPs.
|
|
*
|
|
* Register the initial OPP table with the OPP library for given device.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function indirectly uses RCU updater strategy with mutex locks
|
|
* to keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex cannot be locked.
|
|
*
|
|
* Return:
|
|
* 0 On success OR
|
|
* Duplicate OPPs (both freq and volt are same) and opp->available
|
|
* -EEXIST Freq are same and volt are different OR
|
|
* Duplicate OPPs (both freq and volt are same) and !opp->available
|
|
* -ENOMEM Memory allocation failure
|
|
* -ENODEV when 'operating-points' property is not found or is invalid data
|
|
* in device node.
|
|
* -ENODATA when empty 'operating-points' property is found
|
|
*/
|
|
int of_init_opp_table(struct device *dev)
|
|
{
|
|
const struct property *prop;
|
|
const __be32 *val;
|
|
int nr;
|
|
|
|
prop = of_find_property(dev->of_node, "operating-points", NULL);
|
|
if (!prop)
|
|
return -ENODEV;
|
|
if (!prop->value)
|
|
return -ENODATA;
|
|
|
|
/*
|
|
* Each OPP is a set of tuples consisting of frequency and
|
|
* voltage like <freq-kHz vol-uV>.
|
|
*/
|
|
nr = prop->length / sizeof(u32);
|
|
if (nr % 2) {
|
|
dev_err(dev, "%s: Invalid OPP list\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
val = prop->value;
|
|
while (nr) {
|
|
unsigned long freq = be32_to_cpup(val++) * 1000;
|
|
unsigned long volt = be32_to_cpup(val++);
|
|
|
|
if (_opp_add_dynamic(dev, freq, volt, false))
|
|
dev_warn(dev, "%s: Failed to add OPP %ld\n",
|
|
__func__, freq);
|
|
nr -= 2;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_init_opp_table);
|
|
|
|
/**
|
|
* of_free_opp_table() - Free OPP table entries created from static DT entries
|
|
* @dev: device pointer used to lookup device OPPs.
|
|
*
|
|
* Free OPPs created using static entries present in DT.
|
|
*
|
|
* Locking: The internal device_opp and opp structures are RCU protected.
|
|
* Hence this function indirectly uses RCU updater strategy with mutex locks
|
|
* to keep the integrity of the internal data structures. Callers should ensure
|
|
* that this function is *NOT* called under RCU protection or in contexts where
|
|
* mutex cannot be locked.
|
|
*/
|
|
void of_free_opp_table(struct device *dev)
|
|
{
|
|
struct device_opp *dev_opp;
|
|
struct dev_pm_opp *opp, *tmp;
|
|
|
|
/* Check for existing list for 'dev' */
|
|
dev_opp = _find_device_opp(dev);
|
|
if (IS_ERR(dev_opp)) {
|
|
int error = PTR_ERR(dev_opp);
|
|
if (error != -ENODEV)
|
|
WARN(1, "%s: dev_opp: %d\n",
|
|
IS_ERR_OR_NULL(dev) ?
|
|
"Invalid device" : dev_name(dev),
|
|
error);
|
|
return;
|
|
}
|
|
|
|
/* Hold our list modification lock here */
|
|
mutex_lock(&dev_opp_list_lock);
|
|
|
|
/* Free static OPPs */
|
|
list_for_each_entry_safe(opp, tmp, &dev_opp->opp_list, node) {
|
|
if (!opp->dynamic)
|
|
_opp_remove(dev_opp, opp);
|
|
}
|
|
|
|
mutex_unlock(&dev_opp_list_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_free_opp_table);
|
|
#endif
|