https://github.com/torvalds/linux
Revision a4412fdd49dc011bcc2c0d81ac4cab7457092650 authored by Steven Rostedt (Google) on 21 November 2022, 15:44:03 UTC, committed by Linus Torvalds on 01 December 2022, 21:14:21 UTC
The config to be able to inject error codes into any function annotated
with ALLOW_ERROR_INJECTION() is enabled when FUNCTION_ERROR_INJECTION is
enabled.  But unfortunately, this is always enabled on x86 when KPROBES
is enabled, and there's no way to turn it off.

As kprobes is useful for observability of the kernel, it is useful to
have it enabled in production environments.  But error injection should
be avoided.  Add a prompt to the config to allow it to be disabled even
when kprobes is enabled, and get rid of the "def_bool y".

This is a kernel debug feature (it's in Kconfig.debug), and should have
never been something enabled by default.

Cc: stable@vger.kernel.org
Fixes: 540adea3809f6 ("error-injection: Separate error-injection from kprobe")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 355479c
Raw File
Tip revision: a4412fdd49dc011bcc2c0d81ac4cab7457092650 authored by Steven Rostedt (Google) on 21 November 2022, 15:44:03 UTC
error-injection: Add prompt for function error injection
Tip revision: a4412fd
core.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic OPP Interface
 *
 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
 *	Nishanth Menon
 *	Romit Dasgupta
 *	Kevin Hilman
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/pm_domain.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/xarray.h>

#include "opp.h"

/*
 * The root of the list of all opp-tables. All opp_table structures branch off
 * from here, with each opp_table containing the list of opps it supports in
 * various states of availability.
 */
LIST_HEAD(opp_tables);

/* OPP tables with uninitialized required OPPs */
LIST_HEAD(lazy_opp_tables);

/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_lock);
/* Flag indicating that opp_tables list is being updated at the moment */
static bool opp_tables_busy;

/* OPP ID allocator */
static DEFINE_XARRAY_ALLOC1(opp_configs);

static bool _find_opp_dev(const struct device *dev, struct opp_table *opp_table)
{
	struct opp_device *opp_dev;
	bool found = false;

	mutex_lock(&opp_table->lock);
	list_for_each_entry(opp_dev, &opp_table->dev_list, node)
		if (opp_dev->dev == dev) {
			found = true;
			break;
		}

	mutex_unlock(&opp_table->lock);
	return found;
}

static struct opp_table *_find_opp_table_unlocked(struct device *dev)
{
	struct opp_table *opp_table;

	list_for_each_entry(opp_table, &opp_tables, node) {
		if (_find_opp_dev(dev, opp_table)) {
			_get_opp_table_kref(opp_table);
			return opp_table;
		}
	}

	return ERR_PTR(-ENODEV);
}

/**
 * _find_opp_table() - find opp_table struct using device pointer
 * @dev:	device pointer used to lookup OPP table
 *
 * Search OPP table for one containing matching device.
 *
 * Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
 * -EINVAL based on type of error.
 *
 * The callers must call dev_pm_opp_put_opp_table() after the table is used.
 */
struct opp_table *_find_opp_table(struct device *dev)
{
	struct opp_table *opp_table;

	if (IS_ERR_OR_NULL(dev)) {
		pr_err("%s: Invalid parameters\n", __func__);
		return ERR_PTR(-EINVAL);
	}

	mutex_lock(&opp_table_lock);
	opp_table = _find_opp_table_unlocked(dev);
	mutex_unlock(&opp_table_lock);

	return opp_table;
}

/*
 * Returns true if multiple clocks aren't there, else returns false with WARN.
 *
 * We don't force clk_count == 1 here as there are users who don't have a clock
 * representation in the OPP table and manage the clock configuration themselves
 * in an platform specific way.
 */
static bool assert_single_clk(struct opp_table *opp_table)
{
	return !WARN_ON(opp_table->clk_count > 1);
}

/**
 * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
 * @opp:	opp for which voltage has to be returned for
 *
 * Return: voltage in micro volt corresponding to the opp, else
 * return 0
 *
 * This is useful only for devices with single power supply.
 */
unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
{
	if (IS_ERR_OR_NULL(opp)) {
		pr_err("%s: Invalid parameters\n", __func__);
		return 0;
	}

	return opp->supplies[0].u_volt;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);

/**
 * dev_pm_opp_get_supplies() - Gets the supply information corresponding to an opp
 * @opp:	opp for which voltage has to be returned for
 * @supplies:	Placeholder for copying the supply information.
 *
 * Return: negative error number on failure, 0 otherwise on success after
 * setting @supplies.
 *
 * This can be used for devices with any number of power supplies. The caller
 * must ensure the @supplies array must contain space for each regulator.
 */
int dev_pm_opp_get_supplies(struct dev_pm_opp *opp,
			    struct dev_pm_opp_supply *supplies)
{
	if (IS_ERR_OR_NULL(opp) || !supplies) {
		pr_err("%s: Invalid parameters\n", __func__);
		return -EINVAL;
	}

	memcpy(supplies, opp->supplies,
	       sizeof(*supplies) * opp->opp_table->regulator_count);
	return 0;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_supplies);

/**
 * dev_pm_opp_get_power() - Gets the power corresponding to an opp
 * @opp:	opp for which power has to be returned for
 *
 * Return: power in micro watt corresponding to the opp, else
 * return 0
 *
 * This is useful only for devices with single power supply.
 */
unsigned long dev_pm_opp_get_power(struct dev_pm_opp *opp)
{
	unsigned long opp_power = 0;
	int i;

	if (IS_ERR_OR_NULL(opp)) {
		pr_err("%s: Invalid parameters\n", __func__);
		return 0;
	}
	for (i = 0; i < opp->opp_table->regulator_count; i++)
		opp_power += opp->supplies[i].u_watt;

	return opp_power;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_power);

/**
 * 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
 */
unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
{
	if (IS_ERR_OR_NULL(opp)) {
		pr_err("%s: Invalid parameters\n", __func__);
		return 0;
	}

	if (!assert_single_clk(opp->opp_table))
		return 0;

	return opp->rates[0];
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);

/**
 * dev_pm_opp_get_level() - Gets the level corresponding to an available opp
 * @opp:	opp for which level value has to be returned for
 *
 * Return: level read from device tree corresponding to the opp, else
 * return 0.
 */
unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)
{
	if (IS_ERR_OR_NULL(opp) || !opp->available) {
		pr_err("%s: Invalid parameters\n", __func__);
		return 0;
	}

	return opp->level;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_level);

/**
 * dev_pm_opp_get_required_pstate() - Gets the required performance state
 *                                    corresponding to an available opp
 * @opp:	opp for which performance state has to be returned for
 * @index:	index of the required opp
 *
 * Return: performance state read from device tree corresponding to the
 * required opp, else return 0.
 */
unsigned int dev_pm_opp_get_required_pstate(struct dev_pm_opp *opp,
					    unsigned int index)
{
	if (IS_ERR_OR_NULL(opp) || !opp->available ||
	    index >= opp->opp_table->required_opp_count) {
		pr_err("%s: Invalid parameters\n", __func__);
		return 0;
	}

	/* required-opps not fully initialized yet */
	if (lazy_linking_pending(opp->opp_table))
		return 0;

	return opp->required_opps[index]->pstate;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_required_pstate);

/**
 * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
 * @opp: opp for which turbo mode is being verified
 *
 * Turbo OPPs are not for normal use, and can be enabled (under certain
 * conditions) for short duration of times to finish high throughput work
 * quickly. Running on them for longer times may overheat the chip.
 *
 * Return: true if opp is turbo opp, else false.
 */
bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
{
	if (IS_ERR_OR_NULL(opp) || !opp->available) {
		pr_err("%s: Invalid parameters\n", __func__);
		return false;
	}

	return opp->turbo;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo);

/**
 * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds
 * @dev:	device for which we do this operation
 *
 * Return: This function returns the max clock latency in nanoseconds.
 */
unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
{
	struct opp_table *opp_table;
	unsigned long clock_latency_ns;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return 0;

	clock_latency_ns = opp_table->clock_latency_ns_max;

	dev_pm_opp_put_opp_table(opp_table);

	return clock_latency_ns;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);

/**
 * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
 * @dev: device for which we do this operation
 *
 * Return: This function returns the max voltage latency in nanoseconds.
 */
unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
{
	struct opp_table *opp_table;
	struct dev_pm_opp *opp;
	struct regulator *reg;
	unsigned long latency_ns = 0;
	int ret, i, count;
	struct {
		unsigned long min;
		unsigned long max;
	} *uV;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return 0;

	/* Regulator may not be required for the device */
	if (!opp_table->regulators)
		goto put_opp_table;

	count = opp_table->regulator_count;

	uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
	if (!uV)
		goto put_opp_table;

	mutex_lock(&opp_table->lock);

	for (i = 0; i < count; i++) {
		uV[i].min = ~0;
		uV[i].max = 0;

		list_for_each_entry(opp, &opp_table->opp_list, node) {
			if (!opp->available)
				continue;

			if (opp->supplies[i].u_volt_min < uV[i].min)
				uV[i].min = opp->supplies[i].u_volt_min;
			if (opp->supplies[i].u_volt_max > uV[i].max)
				uV[i].max = opp->supplies[i].u_volt_max;
		}
	}

	mutex_unlock(&opp_table->lock);

	/*
	 * The caller needs to ensure that opp_table (and hence the regulator)
	 * isn't freed, while we are executing this routine.
	 */
	for (i = 0; i < count; i++) {
		reg = opp_table->regulators[i];
		ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
		if (ret > 0)
			latency_ns += ret * 1000;
	}

	kfree(uV);
put_opp_table:
	dev_pm_opp_put_opp_table(opp_table);

	return latency_ns;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);

/**
 * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
 *					     nanoseconds
 * @dev: device for which we do this operation
 *
 * Return: This function returns the max transition latency, in nanoseconds, to
 * switch from one OPP to other.
 */
unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
{
	return dev_pm_opp_get_max_volt_latency(dev) +
		dev_pm_opp_get_max_clock_latency(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);

/**
 * dev_pm_opp_get_suspend_opp_freq() - Get frequency of suspend opp in Hz
 * @dev:	device for which we do this operation
 *
 * Return: This function returns the frequency of the OPP marked as suspend_opp
 * if one is available, else returns 0;
 */
unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
{
	struct opp_table *opp_table;
	unsigned long freq = 0;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return 0;

	if (opp_table->suspend_opp && opp_table->suspend_opp->available)
		freq = dev_pm_opp_get_freq(opp_table->suspend_opp);

	dev_pm_opp_put_opp_table(opp_table);

	return freq;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);

int _get_opp_count(struct opp_table *opp_table)
{
	struct dev_pm_opp *opp;
	int count = 0;

	mutex_lock(&opp_table->lock);

	list_for_each_entry(opp, &opp_table->opp_list, node) {
		if (opp->available)
			count++;
	}

	mutex_unlock(&opp_table->lock);

	return count;
}

/**
 * dev_pm_opp_get_opp_count() - Get number of opps available in the opp table
 * @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.
 */
int dev_pm_opp_get_opp_count(struct device *dev)
{
	struct opp_table *opp_table;
	int count;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		count = PTR_ERR(opp_table);
		dev_dbg(dev, "%s: OPP table not found (%d)\n",
			__func__, count);
		return count;
	}

	count = _get_opp_count(opp_table);
	dev_pm_opp_put_opp_table(opp_table);

	return count;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);

/* Helpers to read keys */
static unsigned long _read_freq(struct dev_pm_opp *opp, int index)
{
	return opp->rates[0];
}

static unsigned long _read_level(struct dev_pm_opp *opp, int index)
{
	return opp->level;
}

static unsigned long _read_bw(struct dev_pm_opp *opp, int index)
{
	return opp->bandwidth[index].peak;
}

/* Generic comparison helpers */
static bool _compare_exact(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
			   unsigned long opp_key, unsigned long key)
{
	if (opp_key == key) {
		*opp = temp_opp;
		return true;
	}

	return false;
}

static bool _compare_ceil(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
			  unsigned long opp_key, unsigned long key)
{
	if (opp_key >= key) {
		*opp = temp_opp;
		return true;
	}

	return false;
}

static bool _compare_floor(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
			   unsigned long opp_key, unsigned long key)
{
	if (opp_key > key)
		return true;

	*opp = temp_opp;
	return false;
}

/* Generic key finding helpers */
static struct dev_pm_opp *_opp_table_find_key(struct opp_table *opp_table,
		unsigned long *key, int index, bool available,
		unsigned long (*read)(struct dev_pm_opp *opp, int index),
		bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
				unsigned long opp_key, unsigned long key),
		bool (*assert)(struct opp_table *opp_table))
{
	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);

	/* Assert that the requirement is met */
	if (assert && !assert(opp_table))
		return ERR_PTR(-EINVAL);

	mutex_lock(&opp_table->lock);

	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
		if (temp_opp->available == available) {
			if (compare(&opp, temp_opp, read(temp_opp, index), *key))
				break;
		}
	}

	/* Increment the reference count of OPP */
	if (!IS_ERR(opp)) {
		*key = read(opp, index);
		dev_pm_opp_get(opp);
	}

	mutex_unlock(&opp_table->lock);

	return opp;
}

static struct dev_pm_opp *
_find_key(struct device *dev, unsigned long *key, int index, bool available,
	  unsigned long (*read)(struct dev_pm_opp *opp, int index),
	  bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
			  unsigned long opp_key, unsigned long key),
	  bool (*assert)(struct opp_table *opp_table))
{
	struct opp_table *opp_table;
	struct dev_pm_opp *opp;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		dev_err(dev, "%s: OPP table not found (%ld)\n", __func__,
			PTR_ERR(opp_table));
		return ERR_CAST(opp_table);
	}

	opp = _opp_table_find_key(opp_table, key, index, available, read,
				  compare, assert);

	dev_pm_opp_put_opp_table(opp_table);

	return opp;
}

static struct dev_pm_opp *_find_key_exact(struct device *dev,
		unsigned long key, int index, bool available,
		unsigned long (*read)(struct dev_pm_opp *opp, int index),
		bool (*assert)(struct opp_table *opp_table))
{
	/*
	 * The value of key will be updated here, but will be ignored as the
	 * caller doesn't need it.
	 */
	return _find_key(dev, &key, index, available, read, _compare_exact,
			 assert);
}

static struct dev_pm_opp *_opp_table_find_key_ceil(struct opp_table *opp_table,
		unsigned long *key, int index, bool available,
		unsigned long (*read)(struct dev_pm_opp *opp, int index),
		bool (*assert)(struct opp_table *opp_table))
{
	return _opp_table_find_key(opp_table, key, index, available, read,
				   _compare_ceil, assert);
}

static struct dev_pm_opp *_find_key_ceil(struct device *dev, unsigned long *key,
		int index, bool available,
		unsigned long (*read)(struct dev_pm_opp *opp, int index),
		bool (*assert)(struct opp_table *opp_table))
{
	return _find_key(dev, key, index, available, read, _compare_ceil,
			 assert);
}

static struct dev_pm_opp *_find_key_floor(struct device *dev,
		unsigned long *key, int index, bool available,
		unsigned long (*read)(struct dev_pm_opp *opp, int index),
		bool (*assert)(struct opp_table *opp_table))
{
	return _find_key(dev, key, index, available, read, _compare_floor,
			 assert);
}

/**
 * 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 table 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.
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
		unsigned long freq, bool available)
{
	return _find_key_exact(dev, freq, 0, available, _read_freq,
			       assert_single_clk);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);

static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
						   unsigned long *freq)
{
	return _opp_table_find_key_ceil(opp_table, freq, 0, true, _read_freq,
					assert_single_clk);
}

/**
 * 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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
					     unsigned long *freq)
{
	return _find_key_ceil(dev, freq, 0, true, _read_freq, assert_single_clk);
}
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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
					      unsigned long *freq)
{
	return _find_key_floor(dev, freq, 0, true, _read_freq, assert_single_clk);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);

/**
 * dev_pm_opp_find_level_exact() - search for an exact level
 * @dev:		device for which we do this operation
 * @level:		level to search for
 *
 * Return: Searches for exact match in the opp table 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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
					       unsigned int level)
{
	return _find_key_exact(dev, level, 0, true, _read_level, NULL);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact);

/**
 * dev_pm_opp_find_level_ceil() - search for an rounded up level
 * @dev:		device for which we do this operation
 * @level:		level to search for
 *
 * Return: Searches for rounded up match in the opp table 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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev,
					      unsigned int *level)
{
	unsigned long temp = *level;
	struct dev_pm_opp *opp;

	opp = _find_key_ceil(dev, &temp, 0, true, _read_level, NULL);
	*level = temp;
	return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_ceil);

/**
 * dev_pm_opp_find_bw_ceil() - Search for a rounded ceil bandwidth
 * @dev:	device for which we do this operation
 * @bw:	start bandwidth
 * @index:	which bandwidth to compare, in case of OPPs with several values
 *
 * Search for the matching floor *available* OPP from a starting bandwidth
 * for a device.
 *
 * Return: matching *opp and refreshes *bw 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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_bw_ceil(struct device *dev, unsigned int *bw,
					   int index)
{
	unsigned long temp = *bw;
	struct dev_pm_opp *opp;

	opp = _find_key_ceil(dev, &temp, index, true, _read_bw, NULL);
	*bw = temp;
	return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_bw_ceil);

/**
 * dev_pm_opp_find_bw_floor() - Search for a rounded floor bandwidth
 * @dev:	device for which we do this operation
 * @bw:	start bandwidth
 * @index:	which bandwidth to compare, in case of OPPs with several values
 *
 * Search for the matching floor *available* OPP from a starting bandwidth
 * for a device.
 *
 * Return: matching *opp and refreshes *bw 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
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 */
struct dev_pm_opp *dev_pm_opp_find_bw_floor(struct device *dev,
					    unsigned int *bw, int index)
{
	unsigned long temp = *bw;
	struct dev_pm_opp *opp;

	opp = _find_key_floor(dev, &temp, index, true, _read_bw, NULL);
	*bw = temp;
	return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_bw_floor);

static int _set_opp_voltage(struct device *dev, struct regulator *reg,
			    struct dev_pm_opp_supply *supply)
{
	int ret;

	/* Regulator not available for device */
	if (IS_ERR(reg)) {
		dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
			PTR_ERR(reg));
		return 0;
	}

	dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__,
		supply->u_volt_min, supply->u_volt, supply->u_volt_max);

	ret = regulator_set_voltage_triplet(reg, supply->u_volt_min,
					    supply->u_volt, supply->u_volt_max);
	if (ret)
		dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
			__func__, supply->u_volt_min, supply->u_volt,
			supply->u_volt_max, ret);

	return ret;
}

static int
_opp_config_clk_single(struct device *dev, struct opp_table *opp_table,
		       struct dev_pm_opp *opp, void *data, bool scaling_down)
{
	unsigned long *target = data;
	unsigned long freq;
	int ret;

	/* One of target and opp must be available */
	if (target) {
		freq = *target;
	} else if (opp) {
		freq = opp->rates[0];
	} else {
		WARN_ON(1);
		return -EINVAL;
	}

	ret = clk_set_rate(opp_table->clk, freq);
	if (ret) {
		dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
			ret);
	} else {
		opp_table->rate_clk_single = freq;
	}

	return ret;
}

/*
 * Simple implementation for configuring multiple clocks. Configure clocks in
 * the order in which they are present in the array while scaling up.
 */
int dev_pm_opp_config_clks_simple(struct device *dev,
		struct opp_table *opp_table, struct dev_pm_opp *opp, void *data,
		bool scaling_down)
{
	int ret, i;

	if (scaling_down) {
		for (i = opp_table->clk_count - 1; i >= 0; i--) {
			ret = clk_set_rate(opp_table->clks[i], opp->rates[i]);
			if (ret) {
				dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
					ret);
				return ret;
			}
		}
	} else {
		for (i = 0; i < opp_table->clk_count; i++) {
			ret = clk_set_rate(opp_table->clks[i], opp->rates[i]);
			if (ret) {
				dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
					ret);
				return ret;
			}
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_config_clks_simple);

static int _opp_config_regulator_single(struct device *dev,
			struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
			struct regulator **regulators, unsigned int count)
{
	struct regulator *reg = regulators[0];
	int ret;

	/* This function only supports single regulator per device */
	if (WARN_ON(count > 1)) {
		dev_err(dev, "multiple regulators are not supported\n");
		return -EINVAL;
	}

	ret = _set_opp_voltage(dev, reg, new_opp->supplies);
	if (ret)
		return ret;

	/*
	 * Enable the regulator after setting its voltages, otherwise it breaks
	 * some boot-enabled regulators.
	 */
	if (unlikely(!new_opp->opp_table->enabled)) {
		ret = regulator_enable(reg);
		if (ret < 0)
			dev_warn(dev, "Failed to enable regulator: %d", ret);
	}

	return 0;
}

static int _set_opp_bw(const struct opp_table *opp_table,
		       struct dev_pm_opp *opp, struct device *dev)
{
	u32 avg, peak;
	int i, ret;

	if (!opp_table->paths)
		return 0;

	for (i = 0; i < opp_table->path_count; i++) {
		if (!opp) {
			avg = 0;
			peak = 0;
		} else {
			avg = opp->bandwidth[i].avg;
			peak = opp->bandwidth[i].peak;
		}
		ret = icc_set_bw(opp_table->paths[i], avg, peak);
		if (ret) {
			dev_err(dev, "Failed to %s bandwidth[%d]: %d\n",
				opp ? "set" : "remove", i, ret);
			return ret;
		}
	}

	return 0;
}

static int _set_required_opp(struct device *dev, struct device *pd_dev,
			     struct dev_pm_opp *opp, int i)
{
	unsigned int pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
	int ret;

	if (!pd_dev)
		return 0;

	ret = dev_pm_genpd_set_performance_state(pd_dev, pstate);
	if (ret) {
		dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
			dev_name(pd_dev), pstate, ret);
	}

	return ret;
}

/* This is only called for PM domain for now */
static int _set_required_opps(struct device *dev,
			      struct opp_table *opp_table,
			      struct dev_pm_opp *opp, bool up)
{
	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
	struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
	int i, ret = 0;

	if (!required_opp_tables)
		return 0;

	/* required-opps not fully initialized yet */
	if (lazy_linking_pending(opp_table))
		return -EBUSY;

	/*
	 * We only support genpd's OPPs in the "required-opps" for now, as we
	 * don't know much about other use cases. Error out if the required OPP
	 * doesn't belong to a genpd.
	 */
	if (unlikely(!required_opp_tables[0]->is_genpd)) {
		dev_err(dev, "required-opps don't belong to a genpd\n");
		return -ENOENT;
	}

	/* Single genpd case */
	if (!genpd_virt_devs)
		return _set_required_opp(dev, dev, opp, 0);

	/* Multiple genpd case */

	/*
	 * Acquire genpd_virt_dev_lock to make sure we don't use a genpd_dev
	 * after it is freed from another thread.
	 */
	mutex_lock(&opp_table->genpd_virt_dev_lock);

	/* Scaling up? Set required OPPs in normal order, else reverse */
	if (up) {
		for (i = 0; i < opp_table->required_opp_count; i++) {
			ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
			if (ret)
				break;
		}
	} else {
		for (i = opp_table->required_opp_count - 1; i >= 0; i--) {
			ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
			if (ret)
				break;
		}
	}

	mutex_unlock(&opp_table->genpd_virt_dev_lock);

	return ret;
}

static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
{
	struct dev_pm_opp *opp = ERR_PTR(-ENODEV);
	unsigned long freq;

	if (!IS_ERR(opp_table->clk)) {
		freq = clk_get_rate(opp_table->clk);
		opp = _find_freq_ceil(opp_table, &freq);
	}

	/*
	 * Unable to find the current OPP ? Pick the first from the list since
	 * it is in ascending order, otherwise rest of the code will need to
	 * make special checks to validate current_opp.
	 */
	if (IS_ERR(opp)) {
		mutex_lock(&opp_table->lock);
		opp = list_first_entry(&opp_table->opp_list, struct dev_pm_opp, node);
		dev_pm_opp_get(opp);
		mutex_unlock(&opp_table->lock);
	}

	opp_table->current_opp = opp;
}

static int _disable_opp_table(struct device *dev, struct opp_table *opp_table)
{
	int ret;

	if (!opp_table->enabled)
		return 0;

	/*
	 * Some drivers need to support cases where some platforms may
	 * have OPP table for the device, while others don't and
	 * opp_set_rate() just needs to behave like clk_set_rate().
	 */
	if (!_get_opp_count(opp_table))
		return 0;

	ret = _set_opp_bw(opp_table, NULL, dev);
	if (ret)
		return ret;

	if (opp_table->regulators)
		regulator_disable(opp_table->regulators[0]);

	ret = _set_required_opps(dev, opp_table, NULL, false);

	opp_table->enabled = false;
	return ret;
}

static int _set_opp(struct device *dev, struct opp_table *opp_table,
		    struct dev_pm_opp *opp, void *clk_data, bool forced)
{
	struct dev_pm_opp *old_opp;
	int scaling_down, ret;

	if (unlikely(!opp))
		return _disable_opp_table(dev, opp_table);

	/* Find the currently set OPP if we don't know already */
	if (unlikely(!opp_table->current_opp))
		_find_current_opp(dev, opp_table);

	old_opp = opp_table->current_opp;

	/* Return early if nothing to do */
	if (!forced && old_opp == opp && opp_table->enabled) {
		dev_dbg(dev, "%s: OPPs are same, nothing to do\n", __func__);
		return 0;
	}

	dev_dbg(dev, "%s: switching OPP: Freq %lu -> %lu Hz, Level %u -> %u, Bw %u -> %u\n",
		__func__, old_opp->rates[0], opp->rates[0], old_opp->level,
		opp->level, old_opp->bandwidth ? old_opp->bandwidth[0].peak : 0,
		opp->bandwidth ? opp->bandwidth[0].peak : 0);

	scaling_down = _opp_compare_key(opp_table, old_opp, opp);
	if (scaling_down == -1)
		scaling_down = 0;

	/* Scaling up? Configure required OPPs before frequency */
	if (!scaling_down) {
		ret = _set_required_opps(dev, opp_table, opp, true);
		if (ret) {
			dev_err(dev, "Failed to set required opps: %d\n", ret);
			return ret;
		}

		ret = _set_opp_bw(opp_table, opp, dev);
		if (ret) {
			dev_err(dev, "Failed to set bw: %d\n", ret);
			return ret;
		}

		if (opp_table->config_regulators) {
			ret = opp_table->config_regulators(dev, old_opp, opp,
							   opp_table->regulators,
							   opp_table->regulator_count);
			if (ret) {
				dev_err(dev, "Failed to set regulator voltages: %d\n",
					ret);
				return ret;
			}
		}
	}

	if (opp_table->config_clks) {
		ret = opp_table->config_clks(dev, opp_table, opp, clk_data, scaling_down);
		if (ret)
			return ret;
	}

	/* Scaling down? Configure required OPPs after frequency */
	if (scaling_down) {
		if (opp_table->config_regulators) {
			ret = opp_table->config_regulators(dev, old_opp, opp,
							   opp_table->regulators,
							   opp_table->regulator_count);
			if (ret) {
				dev_err(dev, "Failed to set regulator voltages: %d\n",
					ret);
				return ret;
			}
		}

		ret = _set_opp_bw(opp_table, opp, dev);
		if (ret) {
			dev_err(dev, "Failed to set bw: %d\n", ret);
			return ret;
		}

		ret = _set_required_opps(dev, opp_table, opp, false);
		if (ret) {
			dev_err(dev, "Failed to set required opps: %d\n", ret);
			return ret;
		}
	}

	opp_table->enabled = true;
	dev_pm_opp_put(old_opp);

	/* Make sure current_opp doesn't get freed */
	dev_pm_opp_get(opp);
	opp_table->current_opp = opp;

	return ret;
}

/**
 * dev_pm_opp_set_rate() - Configure new OPP based on frequency
 * @dev:	 device for which we do this operation
 * @target_freq: frequency to achieve
 *
 * This configures the power-supplies to the levels specified by the OPP
 * corresponding to the target_freq, and programs the clock to a value <=
 * target_freq, as rounded by clk_round_rate(). Device wanting to run at fmax
 * provided by the opp, should have already rounded to the target OPP's
 * frequency.
 */
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
{
	struct opp_table *opp_table;
	unsigned long freq = 0, temp_freq;
	struct dev_pm_opp *opp = NULL;
	bool forced = false;
	int ret;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		dev_err(dev, "%s: device's opp table doesn't exist\n", __func__);
		return PTR_ERR(opp_table);
	}

	if (target_freq) {
		/*
		 * For IO devices which require an OPP on some platforms/SoCs
		 * while just needing to scale the clock on some others
		 * we look for empty OPP tables with just a clock handle and
		 * scale only the clk. This makes dev_pm_opp_set_rate()
		 * equivalent to a clk_set_rate()
		 */
		if (!_get_opp_count(opp_table)) {
			ret = opp_table->config_clks(dev, opp_table, NULL,
						     &target_freq, false);
			goto put_opp_table;
		}

		freq = clk_round_rate(opp_table->clk, target_freq);
		if ((long)freq <= 0)
			freq = target_freq;

		/*
		 * The clock driver may support finer resolution of the
		 * frequencies than the OPP table, don't update the frequency we
		 * pass to clk_set_rate() here.
		 */
		temp_freq = freq;
		opp = _find_freq_ceil(opp_table, &temp_freq);
		if (IS_ERR(opp)) {
			ret = PTR_ERR(opp);
			dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
				__func__, freq, ret);
			goto put_opp_table;
		}

		/*
		 * An OPP entry specifies the highest frequency at which other
		 * properties of the OPP entry apply. Even if the new OPP is
		 * same as the old one, we may still reach here for a different
		 * value of the frequency. In such a case, do not abort but
		 * configure the hardware to the desired frequency forcefully.
		 */
		forced = opp_table->rate_clk_single != target_freq;
	}

	ret = _set_opp(dev, opp_table, opp, &target_freq, forced);

	if (target_freq)
		dev_pm_opp_put(opp);

put_opp_table:
	dev_pm_opp_put_opp_table(opp_table);
	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);

/**
 * dev_pm_opp_set_opp() - Configure device for OPP
 * @dev: device for which we do this operation
 * @opp: OPP to set to
 *
 * This configures the device based on the properties of the OPP passed to this
 * routine.
 *
 * Return: 0 on success, a negative error number otherwise.
 */
int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp)
{
	struct opp_table *opp_table;
	int ret;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		dev_err(dev, "%s: device opp doesn't exist\n", __func__);
		return PTR_ERR(opp_table);
	}

	ret = _set_opp(dev, opp_table, opp, NULL, false);
	dev_pm_opp_put_opp_table(opp_table);

	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_opp);

/* OPP-dev Helpers */
static void _remove_opp_dev(struct opp_device *opp_dev,
			    struct opp_table *opp_table)
{
	opp_debug_unregister(opp_dev, opp_table);
	list_del(&opp_dev->node);
	kfree(opp_dev);
}

struct opp_device *_add_opp_dev(const struct device *dev,
				struct opp_table *opp_table)
{
	struct opp_device *opp_dev;

	opp_dev = kzalloc(sizeof(*opp_dev), GFP_KERNEL);
	if (!opp_dev)
		return NULL;

	/* Initialize opp-dev */
	opp_dev->dev = dev;

	mutex_lock(&opp_table->lock);
	list_add(&opp_dev->node, &opp_table->dev_list);
	mutex_unlock(&opp_table->lock);

	/* Create debugfs entries for the opp_table */
	opp_debug_register(opp_dev, opp_table);

	return opp_dev;
}

static struct opp_table *_allocate_opp_table(struct device *dev, int index)
{
	struct opp_table *opp_table;
	struct opp_device *opp_dev;
	int ret;

	/*
	 * Allocate a new OPP table. In the infrequent case where a new
	 * device is needed to be added, we pay this penalty.
	 */
	opp_table = kzalloc(sizeof(*opp_table), GFP_KERNEL);
	if (!opp_table)
		return ERR_PTR(-ENOMEM);

	mutex_init(&opp_table->lock);
	mutex_init(&opp_table->genpd_virt_dev_lock);
	INIT_LIST_HEAD(&opp_table->dev_list);
	INIT_LIST_HEAD(&opp_table->lazy);

	opp_table->clk = ERR_PTR(-ENODEV);

	/* Mark regulator count uninitialized */
	opp_table->regulator_count = -1;

	opp_dev = _add_opp_dev(dev, opp_table);
	if (!opp_dev) {
		ret = -ENOMEM;
		goto err;
	}

	_of_init_opp_table(opp_table, dev, index);

	/* Find interconnect path(s) for the device */
	ret = dev_pm_opp_of_find_icc_paths(dev, opp_table);
	if (ret) {
		if (ret == -EPROBE_DEFER)
			goto remove_opp_dev;

		dev_warn(dev, "%s: Error finding interconnect paths: %d\n",
			 __func__, ret);
	}

	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
	INIT_LIST_HEAD(&opp_table->opp_list);
	kref_init(&opp_table->kref);

	return opp_table;

remove_opp_dev:
	_remove_opp_dev(opp_dev, opp_table);
err:
	kfree(opp_table);
	return ERR_PTR(ret);
}

void _get_opp_table_kref(struct opp_table *opp_table)
{
	kref_get(&opp_table->kref);
}

static struct opp_table *_update_opp_table_clk(struct device *dev,
					       struct opp_table *opp_table,
					       bool getclk)
{
	int ret;

	/*
	 * Return early if we don't need to get clk or we have already done it
	 * earlier.
	 */
	if (!getclk || IS_ERR(opp_table) || !IS_ERR(opp_table->clk) ||
	    opp_table->clks)
		return opp_table;

	/* Find clk for the device */
	opp_table->clk = clk_get(dev, NULL);

	ret = PTR_ERR_OR_ZERO(opp_table->clk);
	if (!ret) {
		opp_table->config_clks = _opp_config_clk_single;
		opp_table->clk_count = 1;
		return opp_table;
	}

	if (ret == -ENOENT) {
		/*
		 * There are few platforms which don't want the OPP core to
		 * manage device's clock settings. In such cases neither the
		 * platform provides the clks explicitly to us, nor the DT
		 * contains a valid clk entry. The OPP nodes in DT may still
		 * contain "opp-hz" property though, which we need to parse and
		 * allow the platform to find an OPP based on freq later on.
		 *
		 * This is a simple solution to take care of such corner cases,
		 * i.e. make the clk_count 1, which lets us allocate space for
		 * frequency in opp->rates and also parse the entries in DT.
		 */
		opp_table->clk_count = 1;

		dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
		return opp_table;
	}

	dev_pm_opp_put_opp_table(opp_table);
	dev_err_probe(dev, ret, "Couldn't find clock\n");

	return ERR_PTR(ret);
}

/*
 * We need to make sure that the OPP table for a device doesn't get added twice,
 * if this routine gets called in parallel with the same device pointer.
 *
 * The simplest way to enforce that is to perform everything (find existing
 * table and if not found, create a new one) under the opp_table_lock, so only
 * one creator gets access to the same. But that expands the critical section
 * under the lock and may end up causing circular dependencies with frameworks
 * like debugfs, interconnect or clock framework as they may be direct or
 * indirect users of OPP core.
 *
 * And for that reason we have to go for a bit tricky implementation here, which
 * uses the opp_tables_busy flag to indicate if another creator is in the middle
 * of adding an OPP table and others should wait for it to finish.
 */
struct opp_table *_add_opp_table_indexed(struct device *dev, int index,
					 bool getclk)
{
	struct opp_table *opp_table;

again:
	mutex_lock(&opp_table_lock);

	opp_table = _find_opp_table_unlocked(dev);
	if (!IS_ERR(opp_table))
		goto unlock;

	/*
	 * The opp_tables list or an OPP table's dev_list is getting updated by
	 * another user, wait for it to finish.
	 */
	if (unlikely(opp_tables_busy)) {
		mutex_unlock(&opp_table_lock);
		cpu_relax();
		goto again;
	}

	opp_tables_busy = true;
	opp_table = _managed_opp(dev, index);

	/* Drop the lock to reduce the size of critical section */
	mutex_unlock(&opp_table_lock);

	if (opp_table) {
		if (!_add_opp_dev(dev, opp_table)) {
			dev_pm_opp_put_opp_table(opp_table);
			opp_table = ERR_PTR(-ENOMEM);
		}

		mutex_lock(&opp_table_lock);
	} else {
		opp_table = _allocate_opp_table(dev, index);

		mutex_lock(&opp_table_lock);
		if (!IS_ERR(opp_table))
			list_add(&opp_table->node, &opp_tables);
	}

	opp_tables_busy = false;

unlock:
	mutex_unlock(&opp_table_lock);

	return _update_opp_table_clk(dev, opp_table, getclk);
}

static struct opp_table *_add_opp_table(struct device *dev, bool getclk)
{
	return _add_opp_table_indexed(dev, 0, getclk);
}

struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
{
	return _find_opp_table(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);

static void _opp_table_kref_release(struct kref *kref)
{
	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
	struct opp_device *opp_dev, *temp;
	int i;

	/* Drop the lock as soon as we can */
	list_del(&opp_table->node);
	mutex_unlock(&opp_table_lock);

	if (opp_table->current_opp)
		dev_pm_opp_put(opp_table->current_opp);

	_of_clear_opp_table(opp_table);

	/* Release automatically acquired single clk */
	if (!IS_ERR(opp_table->clk))
		clk_put(opp_table->clk);

	if (opp_table->paths) {
		for (i = 0; i < opp_table->path_count; i++)
			icc_put(opp_table->paths[i]);
		kfree(opp_table->paths);
	}

	WARN_ON(!list_empty(&opp_table->opp_list));

	list_for_each_entry_safe(opp_dev, temp, &opp_table->dev_list, node) {
		/*
		 * The OPP table is getting removed, drop the performance state
		 * constraints.
		 */
		if (opp_table->genpd_performance_state)
			dev_pm_genpd_set_performance_state((struct device *)(opp_dev->dev), 0);

		_remove_opp_dev(opp_dev, opp_table);
	}

	mutex_destroy(&opp_table->genpd_virt_dev_lock);
	mutex_destroy(&opp_table->lock);
	kfree(opp_table);
}

void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
{
	kref_put_mutex(&opp_table->kref, _opp_table_kref_release,
		       &opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table);

void _opp_free(struct dev_pm_opp *opp)
{
	kfree(opp);
}

static void _opp_kref_release(struct kref *kref)
{
	struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
	struct opp_table *opp_table = opp->opp_table;

	list_del(&opp->node);
	mutex_unlock(&opp_table->lock);

	/*
	 * Notify the changes in the availability of the operable
	 * frequency/voltage list.
	 */
	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
	_of_clear_opp(opp_table, opp);
	opp_debug_remove_one(opp);
	kfree(opp);
}

void dev_pm_opp_get(struct dev_pm_opp *opp)
{
	kref_get(&opp->kref);
}

void dev_pm_opp_put(struct dev_pm_opp *opp)
{
	kref_put_mutex(&opp->kref, _opp_kref_release, &opp->opp_table->lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put);

/**
 * dev_pm_opp_remove()  - Remove an OPP from OPP table
 * @dev:	device for which we do this operation
 * @freq:	OPP to remove with matching 'freq'
 *
 * This function removes an opp from the opp table.
 */
void dev_pm_opp_remove(struct device *dev, unsigned long freq)
{
	struct dev_pm_opp *opp = NULL, *iter;
	struct opp_table *opp_table;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return;

	if (!assert_single_clk(opp_table))
		goto put_table;

	mutex_lock(&opp_table->lock);

	list_for_each_entry(iter, &opp_table->opp_list, node) {
		if (iter->rates[0] == freq) {
			opp = iter;
			break;
		}
	}

	mutex_unlock(&opp_table->lock);

	if (opp) {
		dev_pm_opp_put(opp);

		/* Drop the reference taken by dev_pm_opp_add() */
		dev_pm_opp_put_opp_table(opp_table);
	} else {
		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
			 __func__, freq);
	}

put_table:
	/* Drop the reference taken by _find_opp_table() */
	dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);

static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
					bool dynamic)
{
	struct dev_pm_opp *opp = NULL, *temp;

	mutex_lock(&opp_table->lock);
	list_for_each_entry(temp, &opp_table->opp_list, node) {
		/*
		 * Refcount must be dropped only once for each OPP by OPP core,
		 * do that with help of "removed" flag.
		 */
		if (!temp->removed && dynamic == temp->dynamic) {
			opp = temp;
			break;
		}
	}

	mutex_unlock(&opp_table->lock);
	return opp;
}

/*
 * Can't call dev_pm_opp_put() from under the lock as debugfs removal needs to
 * happen lock less to avoid circular dependency issues. This routine must be
 * called without the opp_table->lock held.
 */
static void _opp_remove_all(struct opp_table *opp_table, bool dynamic)
{
	struct dev_pm_opp *opp;

	while ((opp = _opp_get_next(opp_table, dynamic))) {
		opp->removed = true;
		dev_pm_opp_put(opp);

		/* Drop the references taken by dev_pm_opp_add() */
		if (dynamic)
			dev_pm_opp_put_opp_table(opp_table);
	}
}

bool _opp_remove_all_static(struct opp_table *opp_table)
{
	mutex_lock(&opp_table->lock);

	if (!opp_table->parsed_static_opps) {
		mutex_unlock(&opp_table->lock);
		return false;
	}

	if (--opp_table->parsed_static_opps) {
		mutex_unlock(&opp_table->lock);
		return true;
	}

	mutex_unlock(&opp_table->lock);

	_opp_remove_all(opp_table, false);
	return true;
}

/**
 * dev_pm_opp_remove_all_dynamic() - Remove all dynamically created OPPs
 * @dev:	device for which we do this operation
 *
 * This function removes all dynamically created OPPs from the opp table.
 */
void dev_pm_opp_remove_all_dynamic(struct device *dev)
{
	struct opp_table *opp_table;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return;

	_opp_remove_all(opp_table, true);

	/* Drop the reference taken by _find_opp_table() */
	dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove_all_dynamic);

struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table)
{
	struct dev_pm_opp *opp;
	int supply_count, supply_size, icc_size, clk_size;

	/* Allocate space for at least one supply */
	supply_count = opp_table->regulator_count > 0 ?
			opp_table->regulator_count : 1;
	supply_size = sizeof(*opp->supplies) * supply_count;
	clk_size = sizeof(*opp->rates) * opp_table->clk_count;
	icc_size = sizeof(*opp->bandwidth) * opp_table->path_count;

	/* allocate new OPP node and supplies structures */
	opp = kzalloc(sizeof(*opp) + supply_size + clk_size + icc_size, GFP_KERNEL);
	if (!opp)
		return NULL;

	/* Put the supplies, bw and clock at the end of the OPP structure */
	opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);

	opp->rates = (unsigned long *)(opp->supplies + supply_count);

	if (icc_size)
		opp->bandwidth = (struct dev_pm_opp_icc_bw *)(opp->rates + opp_table->clk_count);

	INIT_LIST_HEAD(&opp->node);

	return opp;
}

static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
					 struct opp_table *opp_table)
{
	struct regulator *reg;
	int i;

	if (!opp_table->regulators)
		return true;

	for (i = 0; i < opp_table->regulator_count; i++) {
		reg = opp_table->regulators[i];

		if (!regulator_is_supported_voltage(reg,
					opp->supplies[i].u_volt_min,
					opp->supplies[i].u_volt_max)) {
			pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
				__func__, opp->supplies[i].u_volt_min,
				opp->supplies[i].u_volt_max);
			return false;
		}
	}

	return true;
}

static int _opp_compare_rate(struct opp_table *opp_table,
			     struct dev_pm_opp *opp1, struct dev_pm_opp *opp2)
{
	int i;

	for (i = 0; i < opp_table->clk_count; i++) {
		if (opp1->rates[i] != opp2->rates[i])
			return opp1->rates[i] < opp2->rates[i] ? -1 : 1;
	}

	/* Same rates for both OPPs */
	return 0;
}

static int _opp_compare_bw(struct opp_table *opp_table, struct dev_pm_opp *opp1,
			   struct dev_pm_opp *opp2)
{
	int i;

	for (i = 0; i < opp_table->path_count; i++) {
		if (opp1->bandwidth[i].peak != opp2->bandwidth[i].peak)
			return opp1->bandwidth[i].peak < opp2->bandwidth[i].peak ? -1 : 1;
	}

	/* Same bw for both OPPs */
	return 0;
}

/*
 * Returns
 * 0: opp1 == opp2
 * 1: opp1 > opp2
 * -1: opp1 < opp2
 */
int _opp_compare_key(struct opp_table *opp_table, struct dev_pm_opp *opp1,
		     struct dev_pm_opp *opp2)
{
	int ret;

	ret = _opp_compare_rate(opp_table, opp1, opp2);
	if (ret)
		return ret;

	ret = _opp_compare_bw(opp_table, opp1, opp2);
	if (ret)
		return ret;

	if (opp1->level != opp2->level)
		return opp1->level < opp2->level ? -1 : 1;

	/* Duplicate OPPs */
	return 0;
}

static int _opp_is_duplicate(struct device *dev, struct dev_pm_opp *new_opp,
			     struct opp_table *opp_table,
			     struct list_head **head)
{
	struct dev_pm_opp *opp;
	int opp_cmp;

	/*
	 * Insert new OPP in order of increasing frequency and discard if
	 * already present.
	 *
	 * Need to use &opp_table->opp_list in the condition part of the 'for'
	 * loop, don't replace it with head otherwise it will become an infinite
	 * loop.
	 */
	list_for_each_entry(opp, &opp_table->opp_list, node) {
		opp_cmp = _opp_compare_key(opp_table, new_opp, opp);
		if (opp_cmp > 0) {
			*head = &opp->node;
			continue;
		}

		if (opp_cmp < 0)
			return 0;

		/* Duplicate OPPs */
		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
			 __func__, opp->rates[0], opp->supplies[0].u_volt,
			 opp->available, new_opp->rates[0],
			 new_opp->supplies[0].u_volt, new_opp->available);

		/* Should we compare voltages for all regulators here ? */
		return opp->available &&
		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
	}

	return 0;
}

void _required_opps_available(struct dev_pm_opp *opp, int count)
{
	int i;

	for (i = 0; i < count; i++) {
		if (opp->required_opps[i]->available)
			continue;

		opp->available = false;
		pr_warn("%s: OPP not supported by required OPP %pOF (%lu)\n",
			 __func__, opp->required_opps[i]->np, opp->rates[0]);
		return;
	}
}

/*
 * Returns:
 * 0: On success. And appropriate error message for duplicate OPPs.
 * -EBUSY: For OPP with same freq/volt and is available. The callers of
 *  _opp_add() must return 0 if they receive -EBUSY from it. This is to make
 *  sure we don't print error messages unnecessarily if different parts of
 *  kernel try to initialize the OPP table.
 * -EEXIST: For OPP with same freq but different volt or is unavailable. This
 *  should be considered an error by the callers of _opp_add().
 */
int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
	     struct opp_table *opp_table)
{
	struct list_head *head;
	int ret;

	mutex_lock(&opp_table->lock);
	head = &opp_table->opp_list;

	ret = _opp_is_duplicate(dev, new_opp, opp_table, &head);
	if (ret) {
		mutex_unlock(&opp_table->lock);
		return ret;
	}

	list_add(&new_opp->node, head);
	mutex_unlock(&opp_table->lock);

	new_opp->opp_table = opp_table;
	kref_init(&new_opp->kref);

	opp_debug_create_one(new_opp, opp_table);

	if (!_opp_supported_by_regulators(new_opp, opp_table)) {
		new_opp->available = false;
		dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
			 __func__, new_opp->rates[0]);
	}

	/* required-opps not fully initialized yet */
	if (lazy_linking_pending(opp_table))
		return 0;

	_required_opps_available(new_opp, opp_table->required_opp_count);

	return 0;
}

/**
 * _opp_add_v1() - Allocate a OPP based on v1 bindings.
 * @opp_table:	OPP table
 * @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 table 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 dev_pm_opp_of_add_table
 * and freed by dev_pm_opp_of_remove_table.
 *
 * 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 _opp_add_v1(struct opp_table *opp_table, struct device *dev,
		unsigned long freq, long u_volt, bool dynamic)
{
	struct dev_pm_opp *new_opp;
	unsigned long tol;
	int ret;

	if (!assert_single_clk(opp_table))
		return -EINVAL;

	new_opp = _opp_allocate(opp_table);
	if (!new_opp)
		return -ENOMEM;

	/* populate the opp table */
	new_opp->rates[0] = freq;
	tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
	new_opp->supplies[0].u_volt = u_volt;
	new_opp->supplies[0].u_volt_min = u_volt - tol;
	new_opp->supplies[0].u_volt_max = u_volt + tol;
	new_opp->available = true;
	new_opp->dynamic = dynamic;

	ret = _opp_add(dev, new_opp, opp_table);
	if (ret) {
		/* Don't return error for duplicate OPPs */
		if (ret == -EBUSY)
			ret = 0;
		goto free_opp;
	}

	/*
	 * Notify the changes in the availability of the operable
	 * frequency/voltage list.
	 */
	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
	return 0;

free_opp:
	_opp_free(new_opp);

	return ret;
}

/**
 * _opp_set_supported_hw() - Set supported platforms
 * @dev: Device for which supported-hw has to be set.
 * @versions: Array of hierarchy of versions to match.
 * @count: Number of elements in the array.
 *
 * This is required only for the V2 bindings, and it enables a platform to
 * specify the hierarchy of versions it supports. OPP layer will then enable
 * OPPs, which are available for those versions, based on its 'opp-supported-hw'
 * property.
 */
static int _opp_set_supported_hw(struct opp_table *opp_table,
				 const u32 *versions, unsigned int count)
{
	/* Another CPU that shares the OPP table has set the property ? */
	if (opp_table->supported_hw)
		return 0;

	opp_table->supported_hw = kmemdup(versions, count * sizeof(*versions),
					GFP_KERNEL);
	if (!opp_table->supported_hw)
		return -ENOMEM;

	opp_table->supported_hw_count = count;

	return 0;
}

/**
 * _opp_put_supported_hw() - Releases resources blocked for supported hw
 * @opp_table: OPP table returned by _opp_set_supported_hw().
 *
 * This is required only for the V2 bindings, and is called for a matching
 * _opp_set_supported_hw(). Until this is called, the opp_table structure
 * will not be freed.
 */
static void _opp_put_supported_hw(struct opp_table *opp_table)
{
	if (opp_table->supported_hw) {
		kfree(opp_table->supported_hw);
		opp_table->supported_hw = NULL;
		opp_table->supported_hw_count = 0;
	}
}

/**
 * _opp_set_prop_name() - Set prop-extn name
 * @dev: Device for which the prop-name has to be set.
 * @name: name to postfix to properties.
 *
 * This is required only for the V2 bindings, and it enables a platform to
 * specify the extn to be used for certain property names. The properties to
 * which the extension will apply are opp-microvolt and opp-microamp. OPP core
 * should postfix the property name with -<name> while looking for them.
 */
static int _opp_set_prop_name(struct opp_table *opp_table, const char *name)
{
	/* Another CPU that shares the OPP table has set the property ? */
	if (!opp_table->prop_name) {
		opp_table->prop_name = kstrdup(name, GFP_KERNEL);
		if (!opp_table->prop_name)
			return -ENOMEM;
	}

	return 0;
}

/**
 * _opp_put_prop_name() - Releases resources blocked for prop-name
 * @opp_table: OPP table returned by _opp_set_prop_name().
 *
 * This is required only for the V2 bindings, and is called for a matching
 * _opp_set_prop_name(). Until this is called, the opp_table structure
 * will not be freed.
 */
static void _opp_put_prop_name(struct opp_table *opp_table)
{
	if (opp_table->prop_name) {
		kfree(opp_table->prop_name);
		opp_table->prop_name = NULL;
	}
}

/**
 * _opp_set_regulators() - Set regulator names for the device
 * @dev: Device for which regulator name is being set.
 * @names: Array of pointers to the names of the regulator.
 * @count: Number of regulators.
 *
 * In order to support OPP switching, OPP layer needs to know the name of the
 * device's regulators, as the core would be required to switch voltages as
 * well.
 *
 * This must be called before any OPPs are initialized for the device.
 */
static int _opp_set_regulators(struct opp_table *opp_table, struct device *dev,
			       const char * const names[])
{
	const char * const *temp = names;
	struct regulator *reg;
	int count = 0, ret, i;

	/* Count number of regulators */
	while (*temp++)
		count++;

	if (!count)
		return -EINVAL;

	/* Another CPU that shares the OPP table has set the regulators ? */
	if (opp_table->regulators)
		return 0;

	opp_table->regulators = kmalloc_array(count,
					      sizeof(*opp_table->regulators),
					      GFP_KERNEL);
	if (!opp_table->regulators)
		return -ENOMEM;

	for (i = 0; i < count; i++) {
		reg = regulator_get_optional(dev, names[i]);
		if (IS_ERR(reg)) {
			ret = dev_err_probe(dev, PTR_ERR(reg),
					    "%s: no regulator (%s) found\n",
					    __func__, names[i]);
			goto free_regulators;
		}

		opp_table->regulators[i] = reg;
	}

	opp_table->regulator_count = count;

	/* Set generic config_regulators() for single regulators here */
	if (count == 1)
		opp_table->config_regulators = _opp_config_regulator_single;

	return 0;

free_regulators:
	while (i != 0)
		regulator_put(opp_table->regulators[--i]);

	kfree(opp_table->regulators);
	opp_table->regulators = NULL;
	opp_table->regulator_count = -1;

	return ret;
}

/**
 * _opp_put_regulators() - Releases resources blocked for regulator
 * @opp_table: OPP table returned from _opp_set_regulators().
 */
static void _opp_put_regulators(struct opp_table *opp_table)
{
	int i;

	if (!opp_table->regulators)
		return;

	if (opp_table->enabled) {
		for (i = opp_table->regulator_count - 1; i >= 0; i--)
			regulator_disable(opp_table->regulators[i]);
	}

	for (i = opp_table->regulator_count - 1; i >= 0; i--)
		regulator_put(opp_table->regulators[i]);

	kfree(opp_table->regulators);
	opp_table->regulators = NULL;
	opp_table->regulator_count = -1;
}

static void _put_clks(struct opp_table *opp_table, int count)
{
	int i;

	for (i = count - 1; i >= 0; i--)
		clk_put(opp_table->clks[i]);

	kfree(opp_table->clks);
	opp_table->clks = NULL;
}

/**
 * _opp_set_clknames() - Set clk names for the device
 * @dev: Device for which clk names is being set.
 * @names: Clk names.
 *
 * In order to support OPP switching, OPP layer needs to get pointers to the
 * clocks for the device. Simple cases work fine without using this routine
 * (i.e. by passing connection-id as NULL), but for a device with multiple
 * clocks available, the OPP core needs to know the exact names of the clks to
 * use.
 *
 * This must be called before any OPPs are initialized for the device.
 */
static int _opp_set_clknames(struct opp_table *opp_table, struct device *dev,
			     const char * const names[],
			     config_clks_t config_clks)
{
	const char * const *temp = names;
	int count = 0, ret, i;
	struct clk *clk;

	/* Count number of clks */
	while (*temp++)
		count++;

	/*
	 * This is a special case where we have a single clock, whose connection
	 * id name is NULL, i.e. first two entries are NULL in the array.
	 */
	if (!count && !names[1])
		count = 1;

	/* Fail early for invalid configurations */
	if (!count || (!config_clks && count > 1))
		return -EINVAL;

	/* Another CPU that shares the OPP table has set the clkname ? */
	if (opp_table->clks)
		return 0;

	opp_table->clks = kmalloc_array(count, sizeof(*opp_table->clks),
					GFP_KERNEL);
	if (!opp_table->clks)
		return -ENOMEM;

	/* Find clks for the device */
	for (i = 0; i < count; i++) {
		clk = clk_get(dev, names[i]);
		if (IS_ERR(clk)) {
			ret = dev_err_probe(dev, PTR_ERR(clk),
					    "%s: Couldn't find clock with name: %s\n",
					    __func__, names[i]);
			goto free_clks;
		}

		opp_table->clks[i] = clk;
	}

	opp_table->clk_count = count;
	opp_table->config_clks = config_clks;

	/* Set generic single clk set here */
	if (count == 1) {
		if (!opp_table->config_clks)
			opp_table->config_clks = _opp_config_clk_single;

		/*
		 * We could have just dropped the "clk" field and used "clks"
		 * everywhere. Instead we kept the "clk" field around for
		 * following reasons:
		 *
		 * - avoiding clks[0] everywhere else.
		 * - not running single clk helpers for multiple clk usecase by
		 *   mistake.
		 *
		 * Since this is single-clk case, just update the clk pointer
		 * too.
		 */
		opp_table->clk = opp_table->clks[0];
	}

	return 0;

free_clks:
	_put_clks(opp_table, i);
	return ret;
}

/**
 * _opp_put_clknames() - Releases resources blocked for clks.
 * @opp_table: OPP table returned from _opp_set_clknames().
 */
static void _opp_put_clknames(struct opp_table *opp_table)
{
	if (!opp_table->clks)
		return;

	opp_table->config_clks = NULL;
	opp_table->clk = ERR_PTR(-ENODEV);

	_put_clks(opp_table, opp_table->clk_count);
}

/**
 * _opp_set_config_regulators_helper() - Register custom set regulator helper.
 * @dev: Device for which the helper is getting registered.
 * @config_regulators: Custom set regulator helper.
 *
 * This is useful to support platforms with multiple regulators per device.
 *
 * This must be called before any OPPs are initialized for the device.
 */
static int _opp_set_config_regulators_helper(struct opp_table *opp_table,
		struct device *dev, config_regulators_t config_regulators)
{
	/* Another CPU that shares the OPP table has set the helper ? */
	if (!opp_table->config_regulators)
		opp_table->config_regulators = config_regulators;

	return 0;
}

/**
 * _opp_put_config_regulators_helper() - Releases resources blocked for
 *					 config_regulators helper.
 * @opp_table: OPP table returned from _opp_set_config_regulators_helper().
 *
 * Release resources blocked for platform specific config_regulators helper.
 */
static void _opp_put_config_regulators_helper(struct opp_table *opp_table)
{
	if (opp_table->config_regulators)
		opp_table->config_regulators = NULL;
}

static void _detach_genpd(struct opp_table *opp_table)
{
	int index;

	if (!opp_table->genpd_virt_devs)
		return;

	for (index = 0; index < opp_table->required_opp_count; index++) {
		if (!opp_table->genpd_virt_devs[index])
			continue;

		dev_pm_domain_detach(opp_table->genpd_virt_devs[index], false);
		opp_table->genpd_virt_devs[index] = NULL;
	}

	kfree(opp_table->genpd_virt_devs);
	opp_table->genpd_virt_devs = NULL;
}

/**
 * _opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
 * @dev: Consumer device for which the genpd is getting attached.
 * @names: Null terminated array of pointers containing names of genpd to attach.
 * @virt_devs: Pointer to return the array of virtual devices.
 *
 * Multiple generic power domains for a device are supported with the help of
 * virtual genpd devices, which are created for each consumer device - genpd
 * pair. These are the device structures which are attached to the power domain
 * and are required by the OPP core to set the performance state of the genpd.
 * The same API also works for the case where single genpd is available and so
 * we don't need to support that separately.
 *
 * This helper will normally be called by the consumer driver of the device
 * "dev", as only that has details of the genpd names.
 *
 * This helper needs to be called once with a list of all genpd to attach.
 * Otherwise the original device structure will be used instead by the OPP core.
 *
 * The order of entries in the names array must match the order in which
 * "required-opps" are added in DT.
 */
static int _opp_attach_genpd(struct opp_table *opp_table, struct device *dev,
			const char * const *names, struct device ***virt_devs)
{
	struct device *virt_dev;
	int index = 0, ret = -EINVAL;
	const char * const *name = names;

	if (opp_table->genpd_virt_devs)
		return 0;

	/*
	 * If the genpd's OPP table isn't already initialized, parsing of the
	 * required-opps fail for dev. We should retry this after genpd's OPP
	 * table is added.
	 */
	if (!opp_table->required_opp_count)
		return -EPROBE_DEFER;

	mutex_lock(&opp_table->genpd_virt_dev_lock);

	opp_table->genpd_virt_devs = kcalloc(opp_table->required_opp_count,
					     sizeof(*opp_table->genpd_virt_devs),
					     GFP_KERNEL);
	if (!opp_table->genpd_virt_devs)
		goto unlock;

	while (*name) {
		if (index >= opp_table->required_opp_count) {
			dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
				*name, opp_table->required_opp_count, index);
			goto err;
		}

		virt_dev = dev_pm_domain_attach_by_name(dev, *name);
		if (IS_ERR_OR_NULL(virt_dev)) {
			ret = PTR_ERR(virt_dev) ? : -ENODEV;
			dev_err(dev, "Couldn't attach to pm_domain: %d\n", ret);
			goto err;
		}

		opp_table->genpd_virt_devs[index] = virt_dev;
		index++;
		name++;
	}

	if (virt_devs)
		*virt_devs = opp_table->genpd_virt_devs;
	mutex_unlock(&opp_table->genpd_virt_dev_lock);

	return 0;

err:
	_detach_genpd(opp_table);
unlock:
	mutex_unlock(&opp_table->genpd_virt_dev_lock);
	return ret;

}

/**
 * _opp_detach_genpd() - Detach genpd(s) from the device.
 * @opp_table: OPP table returned by _opp_attach_genpd().
 *
 * This detaches the genpd(s), resets the virtual device pointers, and puts the
 * OPP table.
 */
static void _opp_detach_genpd(struct opp_table *opp_table)
{
	/*
	 * Acquire genpd_virt_dev_lock to make sure virt_dev isn't getting
	 * used in parallel.
	 */
	mutex_lock(&opp_table->genpd_virt_dev_lock);
	_detach_genpd(opp_table);
	mutex_unlock(&opp_table->genpd_virt_dev_lock);
}

static void _opp_clear_config(struct opp_config_data *data)
{
	if (data->flags & OPP_CONFIG_GENPD)
		_opp_detach_genpd(data->opp_table);
	if (data->flags & OPP_CONFIG_REGULATOR)
		_opp_put_regulators(data->opp_table);
	if (data->flags & OPP_CONFIG_SUPPORTED_HW)
		_opp_put_supported_hw(data->opp_table);
	if (data->flags & OPP_CONFIG_REGULATOR_HELPER)
		_opp_put_config_regulators_helper(data->opp_table);
	if (data->flags & OPP_CONFIG_PROP_NAME)
		_opp_put_prop_name(data->opp_table);
	if (data->flags & OPP_CONFIG_CLK)
		_opp_put_clknames(data->opp_table);

	dev_pm_opp_put_opp_table(data->opp_table);
	kfree(data);
}

/**
 * dev_pm_opp_set_config() - Set OPP configuration for the device.
 * @dev: Device for which configuration is being set.
 * @config: OPP configuration.
 *
 * This allows all device OPP configurations to be performed at once.
 *
 * This must be called before any OPPs are initialized for the device. This may
 * be called multiple times for the same OPP table, for example once for each
 * CPU that share the same table. This must be balanced by the same number of
 * calls to dev_pm_opp_clear_config() in order to free the OPP table properly.
 *
 * This returns a token to the caller, which must be passed to
 * dev_pm_opp_clear_config() to free the resources later. The value of the
 * returned token will be >= 1 for success and negative for errors. The minimum
 * value of 1 is chosen here to make it easy for callers to manage the resource.
 */
int dev_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
{
	struct opp_table *opp_table;
	struct opp_config_data *data;
	unsigned int id;
	int ret;

	data = kmalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	opp_table = _add_opp_table(dev, false);
	if (IS_ERR(opp_table)) {
		kfree(data);
		return PTR_ERR(opp_table);
	}

	data->opp_table = opp_table;
	data->flags = 0;

	/* This should be called before OPPs are initialized */
	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
		ret = -EBUSY;
		goto err;
	}

	/* Configure clocks */
	if (config->clk_names) {
		ret = _opp_set_clknames(opp_table, dev, config->clk_names,
					config->config_clks);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_CLK;
	} else if (config->config_clks) {
		/* Don't allow config callback without clocks */
		ret = -EINVAL;
		goto err;
	}

	/* Configure property names */
	if (config->prop_name) {
		ret = _opp_set_prop_name(opp_table, config->prop_name);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_PROP_NAME;
	}

	/* Configure config_regulators helper */
	if (config->config_regulators) {
		ret = _opp_set_config_regulators_helper(opp_table, dev,
						config->config_regulators);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_REGULATOR_HELPER;
	}

	/* Configure supported hardware */
	if (config->supported_hw) {
		ret = _opp_set_supported_hw(opp_table, config->supported_hw,
					    config->supported_hw_count);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_SUPPORTED_HW;
	}

	/* Configure supplies */
	if (config->regulator_names) {
		ret = _opp_set_regulators(opp_table, dev,
					  config->regulator_names);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_REGULATOR;
	}

	/* Attach genpds */
	if (config->genpd_names) {
		ret = _opp_attach_genpd(opp_table, dev, config->genpd_names,
					config->virt_devs);
		if (ret)
			goto err;

		data->flags |= OPP_CONFIG_GENPD;
	}

	ret = xa_alloc(&opp_configs, &id, data, XA_LIMIT(1, INT_MAX),
		       GFP_KERNEL);
	if (ret)
		goto err;

	return id;

err:
	_opp_clear_config(data);
	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_config);

/**
 * dev_pm_opp_clear_config() - Releases resources blocked for OPP configuration.
 * @opp_table: OPP table returned from dev_pm_opp_set_config().
 *
 * This allows all device OPP configurations to be cleared at once. This must be
 * called once for each call made to dev_pm_opp_set_config(), in order to free
 * the OPPs properly.
 *
 * Currently the first call itself ends up freeing all the OPP configurations,
 * while the later ones only drop the OPP table reference. This works well for
 * now as we would never want to use an half initialized OPP table and want to
 * remove the configurations together.
 */
void dev_pm_opp_clear_config(int token)
{
	struct opp_config_data *data;

	/*
	 * This lets the callers call this unconditionally and keep their code
	 * simple.
	 */
	if (unlikely(token <= 0))
		return;

	data = xa_erase(&opp_configs, token);
	if (WARN_ON(!data))
		return;

	_opp_clear_config(data);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_clear_config);

static void devm_pm_opp_config_release(void *token)
{
	dev_pm_opp_clear_config((unsigned long)token);
}

/**
 * devm_pm_opp_set_config() - Set OPP configuration for the device.
 * @dev: Device for which configuration is being set.
 * @config: OPP configuration.
 *
 * This allows all device OPP configurations to be performed at once.
 * This is a resource-managed variant of dev_pm_opp_set_config().
 *
 * Return: 0 on success and errorno otherwise.
 */
int devm_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
{
	int token = dev_pm_opp_set_config(dev, config);

	if (token < 0)
		return token;

	return devm_add_action_or_reset(dev, devm_pm_opp_config_release,
					(void *) ((unsigned long) token));
}
EXPORT_SYMBOL_GPL(devm_pm_opp_set_config);

/**
 * dev_pm_opp_xlate_required_opp() - Find required OPP for @src_table OPP.
 * @src_table: OPP table which has @dst_table as one of its required OPP table.
 * @dst_table: Required OPP table of the @src_table.
 * @src_opp: OPP from the @src_table.
 *
 * This function returns the OPP (present in @dst_table) pointed out by the
 * "required-opps" property of the @src_opp (present in @src_table).
 *
 * The callers are required to call dev_pm_opp_put() for the returned OPP after
 * use.
 *
 * Return: pointer to 'struct dev_pm_opp' on success and errorno otherwise.
 */
struct dev_pm_opp *dev_pm_opp_xlate_required_opp(struct opp_table *src_table,
						 struct opp_table *dst_table,
						 struct dev_pm_opp *src_opp)
{
	struct dev_pm_opp *opp, *dest_opp = ERR_PTR(-ENODEV);
	int i;

	if (!src_table || !dst_table || !src_opp ||
	    !src_table->required_opp_tables)
		return ERR_PTR(-EINVAL);

	/* required-opps not fully initialized yet */
	if (lazy_linking_pending(src_table))
		return ERR_PTR(-EBUSY);

	for (i = 0; i < src_table->required_opp_count; i++) {
		if (src_table->required_opp_tables[i] == dst_table) {
			mutex_lock(&src_table->lock);

			list_for_each_entry(opp, &src_table->opp_list, node) {
				if (opp == src_opp) {
					dest_opp = opp->required_opps[i];
					dev_pm_opp_get(dest_opp);
					break;
				}
			}

			mutex_unlock(&src_table->lock);
			break;
		}
	}

	if (IS_ERR(dest_opp)) {
		pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__,
		       src_table, dst_table);
	}

	return dest_opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_xlate_required_opp);

/**
 * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table.
 * @src_table: OPP table which has dst_table as one of its required OPP table.
 * @dst_table: Required OPP table of the src_table.
 * @pstate: Current performance state of the src_table.
 *
 * This Returns pstate of the OPP (present in @dst_table) pointed out by the
 * "required-opps" property of the OPP (present in @src_table) which has
 * performance state set to @pstate.
 *
 * Return: Zero or positive performance state on success, otherwise negative
 * value on errors.
 */
int dev_pm_opp_xlate_performance_state(struct opp_table *src_table,
				       struct opp_table *dst_table,
				       unsigned int pstate)
{
	struct dev_pm_opp *opp;
	int dest_pstate = -EINVAL;
	int i;

	/*
	 * Normally the src_table will have the "required_opps" property set to
	 * point to one of the OPPs in the dst_table, but in some cases the
	 * genpd and its master have one to one mapping of performance states
	 * and so none of them have the "required-opps" property set. Return the
	 * pstate of the src_table as it is in such cases.
	 */
	if (!src_table || !src_table->required_opp_count)
		return pstate;

	/* required-opps not fully initialized yet */
	if (lazy_linking_pending(src_table))
		return -EBUSY;

	for (i = 0; i < src_table->required_opp_count; i++) {
		if (src_table->required_opp_tables[i]->np == dst_table->np)
			break;
	}

	if (unlikely(i == src_table->required_opp_count)) {
		pr_err("%s: Couldn't find matching OPP table (%p: %p)\n",
		       __func__, src_table, dst_table);
		return -EINVAL;
	}

	mutex_lock(&src_table->lock);

	list_for_each_entry(opp, &src_table->opp_list, node) {
		if (opp->pstate == pstate) {
			dest_pstate = opp->required_opps[i]->pstate;
			goto unlock;
		}
	}

	pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table,
	       dst_table);

unlock:
	mutex_unlock(&src_table->lock);

	return dest_pstate;
}

/**
 * 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 table and returns status.
 * The opp is made available by default and it can be controlled using
 * dev_pm_opp_enable/disable functions.
 *
 * 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)
{
	struct opp_table *opp_table;
	int ret;

	opp_table = _add_opp_table(dev, true);
	if (IS_ERR(opp_table))
		return PTR_ERR(opp_table);

	/* Fix regulator count for dynamic OPPs */
	opp_table->regulator_count = 1;

	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
	if (ret)
		dev_pm_opp_put_opp_table(opp_table);

	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_add);

/**
 * _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, 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 modification was done OR modification was
 * successful.
 */
static int _opp_set_availability(struct device *dev, unsigned long freq,
				 bool availability_req)
{
	struct opp_table *opp_table;
	struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
	int r = 0;

	/* Find the opp_table */
	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		r = PTR_ERR(opp_table);
		dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
		return r;
	}

	if (!assert_single_clk(opp_table)) {
		r = -EINVAL;
		goto put_table;
	}

	mutex_lock(&opp_table->lock);

	/* Do we have the frequency? */
	list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
		if (tmp_opp->rates[0] == 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;

	opp->available = availability_req;

	dev_pm_opp_get(opp);
	mutex_unlock(&opp_table->lock);

	/* Notify the change of the OPP availability */
	if (availability_req)
		blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ENABLE,
					     opp);
	else
		blocking_notifier_call_chain(&opp_table->head,
					     OPP_EVENT_DISABLE, opp);

	dev_pm_opp_put(opp);
	goto put_table;

unlock:
	mutex_unlock(&opp_table->lock);
put_table:
	dev_pm_opp_put_opp_table(opp_table);
	return r;
}

/**
 * dev_pm_opp_adjust_voltage() - helper to change the voltage of an OPP
 * @dev:		device for which we do this operation
 * @freq:		OPP frequency to adjust voltage of
 * @u_volt:		new OPP target voltage
 * @u_volt_min:		new OPP min voltage
 * @u_volt_max:		new OPP max voltage
 *
 * 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_adjust_voltage(struct device *dev, unsigned long freq,
			      unsigned long u_volt, unsigned long u_volt_min,
			      unsigned long u_volt_max)

{
	struct opp_table *opp_table;
	struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
	int r = 0;

	/* Find the opp_table */
	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		r = PTR_ERR(opp_table);
		dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
		return r;
	}

	if (!assert_single_clk(opp_table)) {
		r = -EINVAL;
		goto put_table;
	}

	mutex_lock(&opp_table->lock);

	/* Do we have the frequency? */
	list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
		if (tmp_opp->rates[0] == freq) {
			opp = tmp_opp;
			break;
		}
	}

	if (IS_ERR(opp)) {
		r = PTR_ERR(opp);
		goto adjust_unlock;
	}

	/* Is update really needed? */
	if (opp->supplies->u_volt == u_volt)
		goto adjust_unlock;

	opp->supplies->u_volt = u_volt;
	opp->supplies->u_volt_min = u_volt_min;
	opp->supplies->u_volt_max = u_volt_max;

	dev_pm_opp_get(opp);
	mutex_unlock(&opp_table->lock);

	/* Notify the voltage change of the OPP */
	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE,
				     opp);

	dev_pm_opp_put(opp);
	goto put_table;

adjust_unlock:
	mutex_unlock(&opp_table->lock);
put_table:
	dev_pm_opp_put_opp_table(opp_table);
	return r;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_adjust_voltage);

/**
 * 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.
 *
 * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
 * copy operation, returns 0 if no modification 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).
 *
 * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
 * copy operation, returns 0 if no modification 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_register_notifier() - Register OPP notifier for the device
 * @dev:	Device for which notifier needs to be registered
 * @nb:		Notifier block to be registered
 *
 * Return: 0 on success or a negative error value.
 */
int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)
{
	struct opp_table *opp_table;
	int ret;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return PTR_ERR(opp_table);

	ret = blocking_notifier_chain_register(&opp_table->head, nb);

	dev_pm_opp_put_opp_table(opp_table);

	return ret;
}
EXPORT_SYMBOL(dev_pm_opp_register_notifier);

/**
 * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device
 * @dev:	Device for which notifier needs to be unregistered
 * @nb:		Notifier block to be unregistered
 *
 * Return: 0 on success or a negative error value.
 */
int dev_pm_opp_unregister_notifier(struct device *dev,
				   struct notifier_block *nb)
{
	struct opp_table *opp_table;
	int ret;

	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return PTR_ERR(opp_table);

	ret = blocking_notifier_chain_unregister(&opp_table->head, nb);

	dev_pm_opp_put_opp_table(opp_table);

	return ret;
}
EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);

/**
 * dev_pm_opp_remove_table() - Free all OPPs associated with the device
 * @dev:	device pointer used to lookup OPP table.
 *
 * Free both OPPs created using static entries present in DT and the
 * dynamically added entries.
 */
void dev_pm_opp_remove_table(struct device *dev)
{
	struct opp_table *opp_table;

	/* Check for existing table for 'dev' */
	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table)) {
		int error = PTR_ERR(opp_table);

		if (error != -ENODEV)
			WARN(1, "%s: opp_table: %d\n",
			     IS_ERR_OR_NULL(dev) ?
					"Invalid device" : dev_name(dev),
			     error);
		return;
	}

	/*
	 * Drop the extra reference only if the OPP table was successfully added
	 * with dev_pm_opp_of_add_table() earlier.
	 **/
	if (_opp_remove_all_static(opp_table))
		dev_pm_opp_put_opp_table(opp_table);

	/* Drop reference taken by _find_opp_table() */
	dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);

/**
 * dev_pm_opp_sync_regulators() - Sync state of voltage regulators
 * @dev:	device for which we do this operation
 *
 * Sync voltage state of the OPP table regulators.
 *
 * Return: 0 on success or a negative error value.
 */
int dev_pm_opp_sync_regulators(struct device *dev)
{
	struct opp_table *opp_table;
	struct regulator *reg;
	int i, ret = 0;

	/* Device may not have OPP table */
	opp_table = _find_opp_table(dev);
	if (IS_ERR(opp_table))
		return 0;

	/* Regulator may not be required for the device */
	if (unlikely(!opp_table->regulators))
		goto put_table;

	/* Nothing to sync if voltage wasn't changed */
	if (!opp_table->enabled)
		goto put_table;

	for (i = 0; i < opp_table->regulator_count; i++) {
		reg = opp_table->regulators[i];
		ret = regulator_sync_voltage(reg);
		if (ret)
			break;
	}
put_table:
	/* Drop reference taken by _find_opp_table() */
	dev_pm_opp_put_opp_table(opp_table);

	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_sync_regulators);
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