linux/drivers/opp/opp.h
Viresh Kumar 922ff0759a opp: Don't drop reference for an OPP table that was never parsed
dev_pm_opp_remove_table() should drop a reference to the OPP table only
if the DT OPP table was parsed earlier with a call to
dev_pm_opp_of_add_table() earlier. Else it may end up dropping the
reference to the OPP table, which was added as a result of other calls
like dev_pm_opp_set_clkname(). And would hence result in undesirable
behavior later on when caller would try to free the resource again.

Fixes: 03758d6026 ("opp: Replace list_kref with a local counter")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-08-31 14:49:47 +05:30

264 lines
8.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Generic OPP Interface
*
* Copyright (C) 2009-2010 Texas Instruments Incorporated.
* Nishanth Menon
* Romit Dasgupta
* Kevin Hilman
*/
#ifndef __DRIVER_OPP_H__
#define __DRIVER_OPP_H__
#include <linux/device.h>
#include <linux/interconnect.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/limits.h>
#include <linux/pm_opp.h>
#include <linux/notifier.h>
struct clk;
struct regulator;
/* Lock to allow exclusive modification to the device and opp lists */
extern struct mutex opp_table_lock;
extern struct list_head opp_tables;
/*
* Internal data structure organization with the OPP layer library is as
* follows:
* opp_tables (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 opp_table structure while each opp
* is represented by the opp structure.
*/
/**
* struct dev_pm_opp - Generic OPP description structure
* @node: opp table 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.
* IMPORTANT: the opp nodes should be maintained in increasing
* order.
* @kref: for reference count of the OPP.
* @available: true/false - marks if this OPP as available or not
* @dynamic: not-created from static DT entries.
* @turbo: true if turbo (boost) OPP
* @suspend: true if suspend OPP
* @pstate: Device's power domain's performance state.
* @rate: Frequency in hertz
* @level: Performance level
* @supplies: Power supplies voltage/current values
* @bandwidth: Interconnect bandwidth values
* @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
* frequency from any other OPP's frequency.
* @required_opps: List of OPPs that are required by this OPP.
* @opp_table: points back to the opp_table struct this opp belongs to
* @np: OPP's device node.
* @dentry: debugfs dentry pointer (per opp)
*
* This structure stores the OPP information for a given device.
*/
struct dev_pm_opp {
struct list_head node;
struct kref kref;
bool available;
bool dynamic;
bool turbo;
bool suspend;
unsigned int pstate;
unsigned long rate;
unsigned int level;
struct dev_pm_opp_supply *supplies;
struct dev_pm_opp_icc_bw *bandwidth;
unsigned long clock_latency_ns;
struct dev_pm_opp **required_opps;
struct opp_table *opp_table;
struct device_node *np;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
#endif
};
/**
* struct opp_device - devices managed by 'struct opp_table'
* @node: list node
* @dev: device to which the struct object belongs
* @dentry: debugfs dentry pointer (per device)
*
* This is an internal data structure maintaining the devices that are managed
* by 'struct opp_table'.
*/
struct opp_device {
struct list_head node;
const struct device *dev;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
#endif
};
enum opp_table_access {
OPP_TABLE_ACCESS_UNKNOWN = 0,
OPP_TABLE_ACCESS_EXCLUSIVE = 1,
OPP_TABLE_ACCESS_SHARED = 2,
};
/**
* struct opp_table - Device opp structure
* @node: table node - contains the devices with OPPs that
* have been registered. Nodes once added are not modified in this
* table.
* @head: notifier head to notify the OPP availability changes.
* @dev_list: list of devices that share these OPPs
* @opp_list: table of opps
* @kref: for reference count of the table.
* @lock: mutex protecting the opp_list and dev_list.
* @np: struct device_node pointer for opp's DT node.
* @clock_latency_ns_max: Max clock latency in nanoseconds.
* @parsed_static_opps: Count of devices for which OPPs are initialized from DT.
* @shared_opp: OPP is shared between multiple devices.
* @suspend_opp: Pointer to OPP to be used during device suspend.
* @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
* @genpd_virt_devs: List of virtual devices for multiple genpd support.
* @required_opp_tables: List of device OPP tables that are required by OPPs in
* this table.
* @required_opp_count: Number of required devices.
* @supported_hw: Array of version number to support.
* @supported_hw_count: Number of elements in supported_hw array.
* @prop_name: A name to postfix to many DT properties, while parsing them.
* @clk: Device's clock handle
* @regulators: Supply regulators
* @regulator_count: Number of power supply regulators. Its value can be -1
* @regulator_enabled: Set to true if regulators were previously enabled.
* (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
* property).
* @paths: Interconnect path handles
* @path_count: Number of interconnect paths
* @genpd_performance_state: Device's power domain support performance state.
* @is_genpd: Marks if the OPP table belongs to a genpd.
* @set_opp: Platform specific set_opp callback
* @set_opp_data: Data to be passed to set_opp callback
* @dentry: debugfs dentry pointer of the real device directory (not links).
* @dentry_name: Name of the real dentry.
*
* @voltage_tolerance_v1: In percentage, for v1 bindings only.
*
* 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.
*/
struct opp_table {
struct list_head node;
struct blocking_notifier_head head;
struct list_head dev_list;
struct list_head opp_list;
struct kref kref;
struct mutex lock;
struct device_node *np;
unsigned long clock_latency_ns_max;
/* For backward compatibility with v1 bindings */
unsigned int voltage_tolerance_v1;
unsigned int parsed_static_opps;
enum opp_table_access shared_opp;
struct dev_pm_opp *suspend_opp;
struct mutex genpd_virt_dev_lock;
struct device **genpd_virt_devs;
struct opp_table **required_opp_tables;
unsigned int required_opp_count;
unsigned int *supported_hw;
unsigned int supported_hw_count;
const char *prop_name;
struct clk *clk;
struct regulator **regulators;
int regulator_count;
bool regulator_enabled;
struct icc_path **paths;
unsigned int path_count;
bool genpd_performance_state;
bool is_genpd;
int (*set_opp)(struct dev_pm_set_opp_data *data);
struct dev_pm_set_opp_data *set_opp_data;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
char dentry_name[NAME_MAX];
#endif
};
/* Routines internal to opp core */
void dev_pm_opp_get(struct dev_pm_opp *opp);
bool _opp_remove_all_static(struct opp_table *opp_table);
void _get_opp_table_kref(struct opp_table *opp_table);
int _get_opp_count(struct opp_table *opp_table);
struct opp_table *_find_opp_table(struct device *dev);
struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table);
void _dev_pm_opp_find_and_remove_table(struct device *dev);
struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table);
void _opp_free(struct dev_pm_opp *opp);
int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2);
int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, int last_cpu);
struct opp_table *_add_opp_table(struct device *dev);
void _put_opp_list_kref(struct opp_table *opp_table);
#ifdef CONFIG_OF
void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index);
void _of_clear_opp_table(struct opp_table *opp_table);
struct opp_table *_managed_opp(struct device *dev, int index);
void _of_opp_free_required_opps(struct opp_table *opp_table,
struct dev_pm_opp *opp);
#else
static inline void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index) {}
static inline void _of_clear_opp_table(struct opp_table *opp_table) {}
static inline struct opp_table *_managed_opp(struct device *dev, int index) { return NULL; }
static inline void _of_opp_free_required_opps(struct opp_table *opp_table,
struct dev_pm_opp *opp) {}
#endif
#ifdef CONFIG_DEBUG_FS
void opp_debug_remove_one(struct dev_pm_opp *opp);
void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table);
void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table);
void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table);
#else
static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
static inline void opp_debug_create_one(struct dev_pm_opp *opp,
struct opp_table *opp_table) { }
static inline void opp_debug_register(struct opp_device *opp_dev,
struct opp_table *opp_table) { }
static inline void opp_debug_unregister(struct opp_device *opp_dev,
struct opp_table *opp_table)
{ }
#endif /* DEBUG_FS */
#endif /* __DRIVER_OPP_H__ */