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linux-stable/include/linux/thermal.h
Rafael J. Wysocki fcecef9a84 thermal: core: Fix thermal zone suspend-resume synchronization 
[ Upstream commit 4e814173a8 ]

There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

 1. The resume code runs in a PM notifier which is invoked after user
    space has been thawed, so it can run concurrently with user space
    which can trigger a thermal zone device removal.  If that happens,
    the thermal zone resume code may use a stale pointer to the next
    list element and crash, because it does not hold thermal_list_lock
    while walking thermal_tz_list.

 2. The thermal zone resume code calls thermal_zone_device_init()
    outside the zone lock, so user space or an update triggered by
    the platform firmware may see an inconsistent state of a
    thermal zone leading to unexpected behavior.

 3. Clearing the in_suspend global variable in thermal_pm_notify()
    allows __thermal_zone_device_update() to continue for all thermal
    zones and it may as well run before the thermal_tz_list walk (or
    at any point during the list walk for that matter) and attempt to
    operate on a thermal zone that has not been resumed yet.  It may
    also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye <bo.ye@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:14:15 +00:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* thermal.h ($Revision: 0 $)
*
* Copyright (C) 2008 Intel Corp
* Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
* Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
*/
#ifndef __THERMAL_H__
#define __THERMAL_H__
#include <linux/of.h>
#include <linux/idr.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include <uapi/linux/thermal.h>
/* invalid cooling state */
#define THERMAL_CSTATE_INVALID -1UL
/* No upper/lower limit requirement */
#define THERMAL_NO_LIMIT ((u32)~0)
/* Default weight of a bound cooling device */
#define THERMAL_WEIGHT_DEFAULT 0
/* use value, which < 0K, to indicate an invalid/uninitialized temperature */
#define THERMAL_TEMP_INVALID -274000
struct thermal_zone_device;
struct thermal_cooling_device;
struct thermal_instance;
struct thermal_attr;
enum thermal_trend {
THERMAL_TREND_STABLE, /* temperature is stable */
THERMAL_TREND_RAISING, /* temperature is raising */
THERMAL_TREND_DROPPING, /* temperature is dropping */
};
/* Thermal notification reason */
enum thermal_notify_event {
THERMAL_EVENT_UNSPECIFIED, /* Unspecified event */
THERMAL_EVENT_TEMP_SAMPLE, /* New Temperature sample */
THERMAL_TRIP_VIOLATED, /* TRIP Point violation */
THERMAL_TRIP_CHANGED, /* TRIP Point temperature changed */
THERMAL_DEVICE_DOWN, /* Thermal device is down */
THERMAL_DEVICE_UP, /* Thermal device is up after a down event */
THERMAL_DEVICE_POWER_CAPABILITY_CHANGED, /* power capability changed */
THERMAL_TABLE_CHANGED, /* Thermal table(s) changed */
THERMAL_EVENT_KEEP_ALIVE, /* Request for user space handler to respond */
};
/**
* struct thermal_trip - representation of a point in temperature domain
* @temperature: temperature value in miliCelsius
* @hysteresis: relative hysteresis in miliCelsius
* @type: trip point type
* @priv: pointer to driver data associated with this trip
*/
struct thermal_trip {
int temperature;
int hysteresis;
enum thermal_trip_type type;
void *priv;
};
struct thermal_zone_device_ops {
int (*bind) (struct thermal_zone_device *,
struct thermal_cooling_device *);
int (*unbind) (struct thermal_zone_device *,
struct thermal_cooling_device *);
int (*get_temp) (struct thermal_zone_device *, int *);
int (*set_trips) (struct thermal_zone_device *, int, int);
int (*change_mode) (struct thermal_zone_device *,
enum thermal_device_mode);
int (*set_trip_temp) (struct thermal_zone_device *, int, int);
int (*set_trip_hyst) (struct thermal_zone_device *, int, int);
int (*get_crit_temp) (struct thermal_zone_device *, int *);
int (*set_emul_temp) (struct thermal_zone_device *, int);
int (*get_trend) (struct thermal_zone_device *,
const struct thermal_trip *, enum thermal_trend *);
void (*hot)(struct thermal_zone_device *);
void (*critical)(struct thermal_zone_device *);
};
struct thermal_cooling_device_ops {
int (*get_max_state) (struct thermal_cooling_device *, unsigned long *);
int (*get_cur_state) (struct thermal_cooling_device *, unsigned long *);
int (*set_cur_state) (struct thermal_cooling_device *, unsigned long);
int (*get_requested_power)(struct thermal_cooling_device *, u32 *);
int (*state2power)(struct thermal_cooling_device *, unsigned long, u32 *);
int (*power2state)(struct thermal_cooling_device *, u32, unsigned long *);
};
struct thermal_cooling_device {
int id;
char *type;
unsigned long max_state;
struct device device;
struct device_node *np;
void *devdata;
void *stats;
const struct thermal_cooling_device_ops *ops;
bool updated; /* true if the cooling device does not need update */
struct mutex lock; /* protect thermal_instances list */
struct list_head thermal_instances;
struct list_head node;
};
/**
* struct thermal_zone_device - structure for a thermal zone
* @id: unique id number for each thermal zone
* @type: the thermal zone device type
* @device: &struct device for this thermal zone
* @trip_temp_attrs: attributes for trip points for sysfs: trip temperature
* @trip_type_attrs: attributes for trip points for sysfs: trip type
* @trip_hyst_attrs: attributes for trip points for sysfs: trip hysteresis
* @mode: current mode of this thermal zone
* @devdata: private pointer for device private data
* @trips: an array of struct thermal_trip
* @num_trips: number of trip points the thermal zone supports
* @trips_disabled; bitmap for disabled trips
* @passive_delay_jiffies: number of jiffies to wait between polls when
* performing passive cooling.
* @polling_delay_jiffies: number of jiffies to wait between polls when
* checking whether trip points have been crossed (0 for
* interrupt driven systems)
* @temperature: current temperature. This is only for core code,
* drivers should use thermal_zone_get_temp() to get the
* current temperature
* @last_temperature: previous temperature read
* @emul_temperature: emulated temperature when using CONFIG_THERMAL_EMULATION
* @passive: 1 if you've crossed a passive trip point, 0 otherwise.
* @prev_low_trip: the low current temperature if you've crossed a passive
trip point.
* @prev_high_trip: the above current temperature if you've crossed a
passive trip point.
* @need_update: if equals 1, thermal_zone_device_update needs to be invoked.
* @ops: operations this &thermal_zone_device supports
* @tzp: thermal zone parameters
* @governor: pointer to the governor for this thermal zone
* @governor_data: private pointer for governor data
* @thermal_instances: list of &struct thermal_instance of this thermal zone
* @ida: &struct ida to generate unique id for this zone's cooling
* devices
* @lock: lock to protect thermal_instances list
* @node: node in thermal_tz_list (in thermal_core.c)
* @poll_queue: delayed work for polling
* @notify_event: Last notification event
* @suspended: thermal zone suspend indicator
*/
struct thermal_zone_device {
int id;
char type[THERMAL_NAME_LENGTH];
struct device device;
struct attribute_group trips_attribute_group;
struct thermal_attr *trip_temp_attrs;
struct thermal_attr *trip_type_attrs;
struct thermal_attr *trip_hyst_attrs;
enum thermal_device_mode mode;
void *devdata;
struct thermal_trip *trips;
int num_trips;
unsigned long trips_disabled; /* bitmap for disabled trips */
unsigned long passive_delay_jiffies;
unsigned long polling_delay_jiffies;
int temperature;
int last_temperature;
int emul_temperature;
int passive;
int prev_low_trip;
int prev_high_trip;
atomic_t need_update;
struct thermal_zone_device_ops *ops;
struct thermal_zone_params *tzp;
struct thermal_governor *governor;
void *governor_data;
struct list_head thermal_instances;
struct ida ida;
struct mutex lock;
struct list_head node;
struct delayed_work poll_queue;
enum thermal_notify_event notify_event;
bool suspended;
};
/**
* struct thermal_governor - structure that holds thermal governor information
* @name: name of the governor
* @bind_to_tz: callback called when binding to a thermal zone. If it
* returns 0, the governor is bound to the thermal zone,
* otherwise it fails.
* @unbind_from_tz: callback called when a governor is unbound from a
* thermal zone.
* @throttle: callback called for every trip point even if temperature is
* below the trip point temperature
* @governor_list: node in thermal_governor_list (in thermal_core.c)
*/
struct thermal_governor {
char name[THERMAL_NAME_LENGTH];
int (*bind_to_tz)(struct thermal_zone_device *tz);
void (*unbind_from_tz)(struct thermal_zone_device *tz);
int (*throttle)(struct thermal_zone_device *tz, int trip);
struct list_head governor_list;
};
/* Structure to define Thermal Zone parameters */
struct thermal_zone_params {
char governor_name[THERMAL_NAME_LENGTH];
/*
* a boolean to indicate if the thermal to hwmon sysfs interface
* is required. when no_hwmon == false, a hwmon sysfs interface
* will be created. when no_hwmon == true, nothing will be done
*/
bool no_hwmon;
/*
* Sustainable power (heat) that this thermal zone can dissipate in
* mW
*/
u32 sustainable_power;
/*
* Proportional parameter of the PID controller when
* overshooting (i.e., when temperature is below the target)
*/
s32 k_po;
/*
* Proportional parameter of the PID controller when
* undershooting
*/
s32 k_pu;
/* Integral parameter of the PID controller */
s32 k_i;
/* Derivative parameter of the PID controller */
s32 k_d;
/* threshold below which the error is no longer accumulated */
s32 integral_cutoff;
/*
* @slope: slope of a linear temperature adjustment curve.
* Used by thermal zone drivers.
*/
int slope;
/*
* @offset: offset of a linear temperature adjustment curve.
* Used by thermal zone drivers (default 0).
*/
int offset;
};
/* Function declarations */
#ifdef CONFIG_THERMAL_OF
struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int id, void *data,
const struct thermal_zone_device_ops *ops);
void devm_thermal_of_zone_unregister(struct device *dev, struct thermal_zone_device *tz);
#else
static inline
struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int id, void *data,
const struct thermal_zone_device_ops *ops)
{
return ERR_PTR(-ENOTSUPP);
}
static inline void devm_thermal_of_zone_unregister(struct device *dev,
struct thermal_zone_device *tz)
{
}
#endif
int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
struct thermal_trip *trip);
int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
struct thermal_trip *trip);
int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
const struct thermal_trip *trip);
int for_each_thermal_trip(struct thermal_zone_device *tz,
int (*cb)(struct thermal_trip *, void *),
void *data);
int thermal_zone_get_num_trips(struct thermal_zone_device *tz);
int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp);
#ifdef CONFIG_THERMAL_ACPI
int thermal_acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp);
int thermal_acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp);
int thermal_acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp);
int thermal_acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp);
#endif
#ifdef CONFIG_THERMAL
struct thermal_zone_device *thermal_zone_device_register_with_trips(
const char *type,
struct thermal_trip *trips,
int num_trips, int mask,
void *devdata,
struct thermal_zone_device_ops *ops,
const struct thermal_zone_params *tzp,
int passive_delay, int polling_delay);
struct thermal_zone_device *thermal_tripless_zone_device_register(
const char *type,
void *devdata,
struct thermal_zone_device_ops *ops,
const struct thermal_zone_params *tzp);
void thermal_zone_device_unregister(struct thermal_zone_device *tz);
void *thermal_zone_device_priv(struct thermal_zone_device *tzd);
const char *thermal_zone_device_type(struct thermal_zone_device *tzd);
int thermal_zone_device_id(struct thermal_zone_device *tzd);
struct device *thermal_zone_device(struct thermal_zone_device *tzd);
int thermal_zone_bind_cooling_device(struct thermal_zone_device *, int,
struct thermal_cooling_device *,
unsigned long, unsigned long,
unsigned int);
int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, int,
struct thermal_cooling_device *);
void thermal_zone_device_update(struct thermal_zone_device *,
enum thermal_notify_event);
void thermal_zone_device_exec(struct thermal_zone_device *tz,
void (*cb)(struct thermal_zone_device *,
unsigned long),
unsigned long data);
struct thermal_cooling_device *thermal_cooling_device_register(const char *,
void *, const struct thermal_cooling_device_ops *);
struct thermal_cooling_device *
thermal_of_cooling_device_register(struct device_node *np, const char *, void *,
const struct thermal_cooling_device_ops *);
struct thermal_cooling_device *
devm_thermal_of_cooling_device_register(struct device *dev,
struct device_node *np,
char *type, void *devdata,
const struct thermal_cooling_device_ops *ops);
void thermal_cooling_device_update(struct thermal_cooling_device *);
void thermal_cooling_device_unregister(struct thermal_cooling_device *);
struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name);
int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp);
int thermal_zone_get_slope(struct thermal_zone_device *tz);
int thermal_zone_get_offset(struct thermal_zone_device *tz);
int thermal_zone_device_enable(struct thermal_zone_device *tz);
int thermal_zone_device_disable(struct thermal_zone_device *tz);
void thermal_zone_device_critical(struct thermal_zone_device *tz);
#else
static inline struct thermal_zone_device *thermal_zone_device_register_with_trips(
const char *type,
struct thermal_trip *trips,
int num_trips, int mask,
void *devdata,
struct thermal_zone_device_ops *ops,
const struct thermal_zone_params *tzp,
int passive_delay, int polling_delay)
{ return ERR_PTR(-ENODEV); }
static inline struct thermal_zone_device *thermal_tripless_zone_device_register(
const char *type,
void *devdata,
struct thermal_zone_device_ops *ops,
const struct thermal_zone_params *tzp)
{ return ERR_PTR(-ENODEV); }
static inline void thermal_zone_device_unregister(struct thermal_zone_device *tz)
{ }
static inline struct thermal_cooling_device *
thermal_cooling_device_register(const char *type, void *devdata,
const struct thermal_cooling_device_ops *ops)
{ return ERR_PTR(-ENODEV); }
static inline struct thermal_cooling_device *
thermal_of_cooling_device_register(struct device_node *np,
const char *type, void *devdata,
const struct thermal_cooling_device_ops *ops)
{ return ERR_PTR(-ENODEV); }
static inline struct thermal_cooling_device *
devm_thermal_of_cooling_device_register(struct device *dev,
struct device_node *np,
char *type, void *devdata,
const struct thermal_cooling_device_ops *ops)
{
return ERR_PTR(-ENODEV);
}
static inline void thermal_cooling_device_unregister(
struct thermal_cooling_device *cdev)
{ }
static inline struct thermal_zone_device *thermal_zone_get_zone_by_name(
const char *name)
{ return ERR_PTR(-ENODEV); }
static inline int thermal_zone_get_temp(
struct thermal_zone_device *tz, int *temp)
{ return -ENODEV; }
static inline int thermal_zone_get_slope(
struct thermal_zone_device *tz)
{ return -ENODEV; }
static inline int thermal_zone_get_offset(
struct thermal_zone_device *tz)
{ return -ENODEV; }
static inline void *thermal_zone_device_priv(struct thermal_zone_device *tz)
{
return NULL;
}
static inline const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
{
return NULL;
}
static inline int thermal_zone_device_id(struct thermal_zone_device *tzd)
{
return -ENODEV;
}
static inline int thermal_zone_device_enable(struct thermal_zone_device *tz)
{ return -ENODEV; }
static inline int thermal_zone_device_disable(struct thermal_zone_device *tz)
{ return -ENODEV; }
#endif /* CONFIG_THERMAL */
#endif /* __THERMAL_H__ */
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