root/drivers/thermal/thermal_netlink.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2020 Linaro Limited
 *
 * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
 *
 * Generic netlink for thermal management framework
 */
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/kernel.h>
#include <net/sock.h>
#include <net/genetlink.h>
#include <uapi/linux/thermal.h>

#include "thermal_core.h"

static const struct genl_multicast_group thermal_genl_mcgrps[] = {
        [THERMAL_GENL_SAMPLING_GROUP] = { .name = THERMAL_GENL_SAMPLING_GROUP_NAME, },
        [THERMAL_GENL_EVENT_GROUP]  = { .name = THERMAL_GENL_EVENT_GROUP_NAME,  },
};

static const struct nla_policy thermal_genl_policy[THERMAL_GENL_ATTR_MAX + 1] = {
        /* Thermal zone */
        [THERMAL_GENL_ATTR_TZ]                  = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_TZ_ID]               = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_TEMP]             = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_TRIP]             = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_TZ_TRIP_ID]          = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_TRIP_TEMP]        = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_TRIP_TYPE]        = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_TRIP_HYST]        = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_MODE]             = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_CDEV_WEIGHT]      = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_TZ_NAME]             = { .type = NLA_STRING,
                                                    .len = THERMAL_NAME_LENGTH },
        /* Governor(s) */
        [THERMAL_GENL_ATTR_TZ_GOV]              = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_TZ_GOV_NAME]         = { .type = NLA_STRING,
                                                    .len = THERMAL_NAME_LENGTH },
        /* Cooling devices */
        [THERMAL_GENL_ATTR_CDEV]                = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_CDEV_ID]             = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_CDEV_CUR_STATE]      = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_CDEV_MAX_STATE]      = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_CDEV_NAME]           = { .type = NLA_STRING,
                                                    .len = THERMAL_NAME_LENGTH },
        /* CPU capabilities */
        [THERMAL_GENL_ATTR_CPU_CAPABILITY]              = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_CPU_CAPABILITY_ID]           = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_CPU_CAPABILITY_PERFORMANCE]  = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_CPU_CAPABILITY_EFFICIENCY]   = { .type = NLA_U32 },

        /* Thresholds */
        [THERMAL_GENL_ATTR_THRESHOLD]           = { .type = NLA_NESTED },
        [THERMAL_GENL_ATTR_THRESHOLD_TEMP]      = { .type = NLA_U32 },
        [THERMAL_GENL_ATTR_THRESHOLD_DIRECTION] = { .type = NLA_U32 },
};

struct param {
        struct nlattr **attrs;
        struct sk_buff *msg;
        const char *name;
        int tz_id;
        int cdev_id;
        int trip_id;
        int trip_temp;
        int trip_type;
        int trip_hyst;
        int temp;
        int prev_temp;
        int direction;
        int cdev_state;
        int cdev_max_state;
        struct thermal_genl_cpu_caps *cpu_capabilities;
        int cpu_capabilities_count;
};

typedef int (*cb_t)(struct param *);

static struct genl_family thermal_genl_family;
static BLOCKING_NOTIFIER_HEAD(thermal_genl_chain);

static int thermal_group_has_listeners(enum thermal_genl_multicast_groups group)
{
        return genl_has_listeners(&thermal_genl_family, &init_net, group);
}

/************************** Sampling encoding *******************************/

int thermal_genl_sampling_temp(int id, int temp)
{
        struct sk_buff *skb;
        void *hdr;

        if (!thermal_group_has_listeners(THERMAL_GENL_SAMPLING_GROUP))
                return 0;

        skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        hdr = genlmsg_put(skb, 0, 0, &thermal_genl_family, 0,
                          THERMAL_GENL_SAMPLING_TEMP);
        if (!hdr)
                goto out_free;

        if (nla_put_u32(skb, THERMAL_GENL_ATTR_TZ_ID, id))
                goto out_cancel;

        if (nla_put_u32(skb, THERMAL_GENL_ATTR_TZ_TEMP, temp))
                goto out_cancel;

        genlmsg_end(skb, hdr);

        genlmsg_multicast(&thermal_genl_family, skb, 0, THERMAL_GENL_SAMPLING_GROUP, GFP_KERNEL);

        return 0;
out_cancel:
        genlmsg_cancel(skb, hdr);
out_free:
        nlmsg_free(skb);

        return -EMSGSIZE;
}

/**************************** Event encoding *********************************/

static int thermal_genl_event_tz_create(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_string(p->msg, THERMAL_GENL_ATTR_TZ_NAME, p->name))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_tz(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_tz_trip_up(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TRIP_ID, p->trip_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TEMP, p->temp))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_tz_trip_change(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TRIP_ID, p->trip_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TRIP_TYPE, p->trip_type) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TRIP_TEMP, p->trip_temp) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TRIP_HYST, p->trip_hyst))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_cdev_add(struct param *p)
{
        if (nla_put_string(p->msg, THERMAL_GENL_ATTR_CDEV_NAME,
                           p->name) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_CDEV_ID,
                        p->cdev_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_CDEV_MAX_STATE,
                        p->cdev_max_state))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_cdev_delete(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_CDEV_ID, p->cdev_id))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_cdev_state_update(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_CDEV_ID,
                        p->cdev_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_CDEV_CUR_STATE,
                        p->cdev_state))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_gov_change(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_string(p->msg, THERMAL_GENL_ATTR_GOV_NAME, p->name))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_cpu_capability_change(struct param *p)
{
        struct thermal_genl_cpu_caps *cpu_cap = p->cpu_capabilities;
        struct sk_buff *msg = p->msg;
        struct nlattr *start_cap;
        int i;

        start_cap = nla_nest_start(msg, THERMAL_GENL_ATTR_CPU_CAPABILITY);
        if (!start_cap)
                return -EMSGSIZE;

        for (i = 0; i < p->cpu_capabilities_count; ++i) {
                if (nla_put_u32(msg, THERMAL_GENL_ATTR_CPU_CAPABILITY_ID,
                                cpu_cap->cpu))
                        goto out_cancel_nest;

                if (nla_put_u32(msg, THERMAL_GENL_ATTR_CPU_CAPABILITY_PERFORMANCE,
                                cpu_cap->performance))
                        goto out_cancel_nest;

                if (nla_put_u32(msg, THERMAL_GENL_ATTR_CPU_CAPABILITY_EFFICIENCY,
                                cpu_cap->efficiency))
                        goto out_cancel_nest;

                ++cpu_cap;
        }

        nla_nest_end(msg, start_cap);

        return 0;
out_cancel_nest:
        nla_nest_cancel(msg, start_cap);

        return -EMSGSIZE;
}

static int thermal_genl_event_threshold_add(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_THRESHOLD_TEMP, p->temp) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_THRESHOLD_DIRECTION, p->direction))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_threshold_flush(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_event_threshold_up(struct param *p)
{
        if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_PREV_TEMP, p->prev_temp) ||
            nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TEMP, p->temp))
                return -EMSGSIZE;

        return 0;
}

int thermal_genl_event_tz_delete(struct param *p)
        __attribute__((alias("thermal_genl_event_tz")));

int thermal_genl_event_tz_enable(struct param *p)
        __attribute__((alias("thermal_genl_event_tz")));

int thermal_genl_event_tz_disable(struct param *p)
        __attribute__((alias("thermal_genl_event_tz")));

int thermal_genl_event_tz_trip_down(struct param *p)
        __attribute__((alias("thermal_genl_event_tz_trip_up")));

int thermal_genl_event_threshold_delete(struct param *p)
        __attribute__((alias("thermal_genl_event_threshold_add")));

int thermal_genl_event_threshold_down(struct param *p)
        __attribute__((alias("thermal_genl_event_threshold_up")));

static cb_t event_cb[] = {
        [THERMAL_GENL_EVENT_TZ_CREATE]          = thermal_genl_event_tz_create,
        [THERMAL_GENL_EVENT_TZ_DELETE]          = thermal_genl_event_tz_delete,
        [THERMAL_GENL_EVENT_TZ_ENABLE]          = thermal_genl_event_tz_enable,
        [THERMAL_GENL_EVENT_TZ_DISABLE]         = thermal_genl_event_tz_disable,
        [THERMAL_GENL_EVENT_TZ_TRIP_UP]         = thermal_genl_event_tz_trip_up,
        [THERMAL_GENL_EVENT_TZ_TRIP_DOWN]       = thermal_genl_event_tz_trip_down,
        [THERMAL_GENL_EVENT_TZ_TRIP_CHANGE]     = thermal_genl_event_tz_trip_change,
        [THERMAL_GENL_EVENT_CDEV_ADD]           = thermal_genl_event_cdev_add,
        [THERMAL_GENL_EVENT_CDEV_DELETE]        = thermal_genl_event_cdev_delete,
        [THERMAL_GENL_EVENT_CDEV_STATE_UPDATE]  = thermal_genl_event_cdev_state_update,
        [THERMAL_GENL_EVENT_TZ_GOV_CHANGE]      = thermal_genl_event_gov_change,
        [THERMAL_GENL_EVENT_CPU_CAPABILITY_CHANGE] = thermal_genl_event_cpu_capability_change,
        [THERMAL_GENL_EVENT_THRESHOLD_ADD]      = thermal_genl_event_threshold_add,
        [THERMAL_GENL_EVENT_THRESHOLD_DELETE]   = thermal_genl_event_threshold_delete,
        [THERMAL_GENL_EVENT_THRESHOLD_FLUSH]    = thermal_genl_event_threshold_flush,
        [THERMAL_GENL_EVENT_THRESHOLD_DOWN]     = thermal_genl_event_threshold_down,
        [THERMAL_GENL_EVENT_THRESHOLD_UP]       = thermal_genl_event_threshold_up,
};

/*
 * Generic netlink event encoding
 */
static int thermal_genl_send_event(enum thermal_genl_event event,
                                   struct param *p)
{
        struct sk_buff *msg;
        int ret = -EMSGSIZE;
        void *hdr;

        if (!thermal_group_has_listeners(THERMAL_GENL_EVENT_GROUP))
                return 0;

        msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;
        p->msg = msg;

        hdr = genlmsg_put(msg, 0, 0, &thermal_genl_family, 0, event);
        if (!hdr)
                goto out_free_msg;

        ret = event_cb[event](p);
        if (ret)
                goto out_cancel_msg;

        genlmsg_end(msg, hdr);

        genlmsg_multicast(&thermal_genl_family, msg, 0, THERMAL_GENL_EVENT_GROUP, GFP_KERNEL);

        return 0;

out_cancel_msg:
        genlmsg_cancel(msg, hdr);
out_free_msg:
        nlmsg_free(msg);

        return ret;
}

int thermal_notify_tz_create(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id, .name = tz->type };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_CREATE, &p);
}

int thermal_notify_tz_delete(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_DELETE, &p);
}

int thermal_notify_tz_enable(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_ENABLE, &p);
}

int thermal_notify_tz_disable(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_DISABLE, &p);
}

int thermal_notify_tz_trip_down(const struct thermal_zone_device *tz,
                                const struct thermal_trip *trip)
{
        struct param p = { .tz_id = tz->id,
                           .trip_id = thermal_zone_trip_id(tz, trip),
                           .temp = tz->temperature };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_TRIP_DOWN, &p);
}

int thermal_notify_tz_trip_up(const struct thermal_zone_device *tz,
                              const struct thermal_trip *trip)
{
        struct param p = { .tz_id = tz->id,
                           .trip_id = thermal_zone_trip_id(tz, trip),
                           .temp = tz->temperature };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_TRIP_UP, &p);
}

int thermal_notify_tz_trip_change(const struct thermal_zone_device *tz,
                                  const struct thermal_trip *trip)
{
        struct param p = { .tz_id = tz->id,
                           .trip_id = thermal_zone_trip_id(tz, trip),
                           .trip_type = trip->type,
                           .trip_temp = trip->temperature,
                           .trip_hyst = trip->hysteresis };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_TRIP_CHANGE, &p);
}

int thermal_notify_cdev_state_update(const struct thermal_cooling_device *cdev,
                                     int state)
{
        struct param p = { .cdev_id = cdev->id, .cdev_state = state };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_CDEV_STATE_UPDATE, &p);
}

int thermal_notify_cdev_add(const struct thermal_cooling_device *cdev)
{
        struct param p = { .cdev_id = cdev->id, .name = cdev->type,
                           .cdev_max_state = cdev->max_state };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_CDEV_ADD, &p);
}

int thermal_notify_cdev_delete(const struct thermal_cooling_device *cdev)
{
        struct param p = { .cdev_id = cdev->id };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_CDEV_DELETE, &p);
}

int thermal_notify_tz_gov_change(const struct thermal_zone_device *tz,
                                 const char *name)
{
        struct param p = { .tz_id = tz->id, .name = name };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_TZ_GOV_CHANGE, &p);
}

int thermal_genl_cpu_capability_event(int count,
                                      struct thermal_genl_cpu_caps *caps)
{
        struct param p = { .cpu_capabilities_count = count, .cpu_capabilities = caps };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_CPU_CAPABILITY_CHANGE, &p);
}
EXPORT_SYMBOL_GPL(thermal_genl_cpu_capability_event);

int thermal_notify_threshold_add(const struct thermal_zone_device *tz,
                                 int temperature, int direction)
{
        struct param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_ADD, &p);
}

int thermal_notify_threshold_delete(const struct thermal_zone_device *tz,
                                    int temperature, int direction)
{
        struct param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_DELETE, &p);
}

int thermal_notify_threshold_flush(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_FLUSH, &p);
}

int thermal_notify_threshold_down(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id, .temp = tz->temperature, .prev_temp = tz->last_temperature };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_DOWN, &p);
}

int thermal_notify_threshold_up(const struct thermal_zone_device *tz)
{
        struct param p = { .tz_id = tz->id, .temp = tz->temperature, .prev_temp = tz->last_temperature };

        return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_UP, &p);
}

/*************************** Command encoding ********************************/

static int __thermal_genl_cmd_tz_get_id(struct thermal_zone_device *tz,
                                        void *data)
{
        struct sk_buff *msg = data;

        if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_ID, tz->id) ||
            nla_put_string(msg, THERMAL_GENL_ATTR_TZ_NAME, tz->type))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_cmd_tz_get_id(struct param *p)
{
        struct sk_buff *msg = p->msg;
        struct nlattr *start_tz;
        int ret;

        start_tz = nla_nest_start(msg, THERMAL_GENL_ATTR_TZ);
        if (!start_tz)
                return -EMSGSIZE;

        ret = for_each_thermal_zone(__thermal_genl_cmd_tz_get_id, msg);
        if (ret)
                goto out_cancel_nest;

        nla_nest_end(msg, start_tz);

        return 0;

out_cancel_nest:
        nla_nest_cancel(msg, start_tz);

        return ret;
}

static int thermal_genl_cmd_tz_get_trip(struct param *p)
{
        struct sk_buff *msg = p->msg;
        const struct thermal_trip_desc *td;
        struct nlattr *start_trip;
        int id;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        start_trip = nla_nest_start(msg, THERMAL_GENL_ATTR_TZ_TRIP);
        if (!start_trip)
                return -EMSGSIZE;

        guard(thermal_zone)(tz);

        for_each_trip_desc(tz, td) {
                const struct thermal_trip *trip = &td->trip;

                if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_ID,
                                thermal_zone_trip_id(tz, trip)) ||
                    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TYPE, trip->type) ||
                    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_TEMP, trip->temperature) ||
                    nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TRIP_HYST, trip->hysteresis))
                        return -EMSGSIZE;
        }

        nla_nest_end(msg, start_trip);

        return 0;
}

static int thermal_genl_cmd_tz_get_temp(struct param *p)
{
        struct sk_buff *msg = p->msg;
        int temp, ret, id;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        ret = thermal_zone_get_temp(tz, &temp);
        if (ret)
                return ret;

        if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_ID, id) ||
            nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_TEMP, temp))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_cmd_tz_get_gov(struct param *p)
{
        struct sk_buff *msg = p->msg;
        int id;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        guard(thermal_zone)(tz);

        if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_ID, id) ||
            nla_put_string(msg, THERMAL_GENL_ATTR_TZ_GOV_NAME,
                           tz->governor->name))
                return -EMSGSIZE;

        return 0;
}

static int __thermal_genl_cmd_cdev_get(struct thermal_cooling_device *cdev,
                                       void *data)
{
        struct sk_buff *msg = data;

        if (nla_put_u32(msg, THERMAL_GENL_ATTR_CDEV_ID, cdev->id))
                return -EMSGSIZE;

        if (nla_put_string(msg, THERMAL_GENL_ATTR_CDEV_NAME, cdev->type))
                return -EMSGSIZE;

        return 0;
}

static int thermal_genl_cmd_cdev_get(struct param *p)
{
        struct sk_buff *msg = p->msg;
        struct nlattr *start_cdev;
        int ret;

        start_cdev = nla_nest_start(msg, THERMAL_GENL_ATTR_CDEV);
        if (!start_cdev)
                return -EMSGSIZE;

        ret = for_each_thermal_cooling_device(__thermal_genl_cmd_cdev_get, msg);
        if (ret)
                goto out_cancel_nest;

        nla_nest_end(msg, start_cdev);

        return 0;
out_cancel_nest:
        nla_nest_cancel(msg, start_cdev);

        return ret;
}

static int __thermal_genl_cmd_threshold_get(struct user_threshold *threshold, void *arg)
{
        struct sk_buff *msg = arg;

        if (nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_TEMP, threshold->temperature) ||
            nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_DIRECTION, threshold->direction))
                return -1;

        return 0;
}

static int thermal_genl_cmd_threshold_get(struct param *p)
{
        struct sk_buff *msg = p->msg;
        struct nlattr *start_trip;
        int id, ret;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        start_trip = nla_nest_start(msg, THERMAL_GENL_ATTR_THRESHOLD);
        if (!start_trip)
                return -EMSGSIZE;

        ret = thermal_thresholds_for_each(tz, __thermal_genl_cmd_threshold_get, msg);
        if (ret)
                return -EMSGSIZE;

        nla_nest_end(msg, start_trip);

        return 0;
}

static int thermal_genl_cmd_threshold_add(struct param *p)
{
        int id, temp, direction;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID] ||
            !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP] ||
            !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
        temp = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]);
        direction = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        guard(thermal_zone)(tz);

        return thermal_thresholds_add(tz, temp, direction);
}

static int thermal_genl_cmd_threshold_delete(struct param *p)
{
        int id, temp, direction;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID] ||
            !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP] ||
            !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
        temp = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]);
        direction = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        guard(thermal_zone)(tz);

        return thermal_thresholds_delete(tz, temp, direction);
}

static int thermal_genl_cmd_threshold_flush(struct param *p)
{
        int id;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
                return -EINVAL;

        id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);

        CLASS(thermal_zone_get_by_id, tz)(id);
        if (!tz)
                return -EINVAL;

        guard(thermal_zone)(tz);

        thermal_thresholds_flush(tz);

        return 0;
}

static cb_t cmd_cb[] = {
        [THERMAL_GENL_CMD_TZ_GET_ID]            = thermal_genl_cmd_tz_get_id,
        [THERMAL_GENL_CMD_TZ_GET_TRIP]          = thermal_genl_cmd_tz_get_trip,
        [THERMAL_GENL_CMD_TZ_GET_TEMP]          = thermal_genl_cmd_tz_get_temp,
        [THERMAL_GENL_CMD_TZ_GET_GOV]           = thermal_genl_cmd_tz_get_gov,
        [THERMAL_GENL_CMD_CDEV_GET]             = thermal_genl_cmd_cdev_get,
        [THERMAL_GENL_CMD_THRESHOLD_GET]        = thermal_genl_cmd_threshold_get,
        [THERMAL_GENL_CMD_THRESHOLD_ADD]        = thermal_genl_cmd_threshold_add,
        [THERMAL_GENL_CMD_THRESHOLD_DELETE]     = thermal_genl_cmd_threshold_delete,
        [THERMAL_GENL_CMD_THRESHOLD_FLUSH]      = thermal_genl_cmd_threshold_flush,
};

static int thermal_genl_cmd_dumpit(struct sk_buff *skb,
                                   struct netlink_callback *cb)
{
        struct param p = { .msg = skb };
        const struct genl_dumpit_info *info = genl_dumpit_info(cb);
        int cmd = info->op.cmd;
        int ret;
        void *hdr;

        hdr = genlmsg_put(skb, 0, 0, &thermal_genl_family, 0, cmd);
        if (!hdr)
                return -EMSGSIZE;

        ret = cmd_cb[cmd](&p);
        if (ret)
                goto out_cancel_msg;

        genlmsg_end(skb, hdr);

        return 0;

out_cancel_msg:
        genlmsg_cancel(skb, hdr);

        return ret;
}

static int thermal_genl_cmd_doit(struct sk_buff *skb,
                                 struct genl_info *info)
{
        struct param p = { .attrs = info->attrs };
        struct sk_buff *msg;
        void *hdr;
        int cmd = info->genlhdr->cmd;
        int ret = -EMSGSIZE;

        msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;
        p.msg = msg;

        hdr = genlmsg_put_reply(msg, info, &thermal_genl_family, 0, cmd);
        if (!hdr)
                goto out_free_msg;

        ret = cmd_cb[cmd](&p);
        if (ret)
                goto out_cancel_msg;

        genlmsg_end(msg, hdr);

        return genlmsg_reply(msg, info);

out_cancel_msg:
        genlmsg_cancel(msg, hdr);
out_free_msg:
        nlmsg_free(msg);

        return ret;
}

static int thermal_genl_bind(int mcgrp)
{
        struct thermal_genl_notify n = { .mcgrp = mcgrp };

        if (WARN_ON_ONCE(mcgrp > THERMAL_GENL_MAX_GROUP))
                return -EINVAL;

        blocking_notifier_call_chain(&thermal_genl_chain, THERMAL_NOTIFY_BIND, &n);
        return 0;
}

static void thermal_genl_unbind(int mcgrp)
{
        struct thermal_genl_notify n = { .mcgrp = mcgrp };

        if (WARN_ON_ONCE(mcgrp > THERMAL_GENL_MAX_GROUP))
                return;

        blocking_notifier_call_chain(&thermal_genl_chain, THERMAL_NOTIFY_UNBIND, &n);
}

static const struct genl_small_ops thermal_genl_ops[] = {
        {
                .cmd = THERMAL_GENL_CMD_TZ_GET_ID,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .dumpit = thermal_genl_cmd_dumpit,
        },
        {
                .cmd = THERMAL_GENL_CMD_TZ_GET_TRIP,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_TZ_GET_TEMP,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_TZ_GET_GOV,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_CDEV_GET,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .dumpit = thermal_genl_cmd_dumpit,
        },
        {
                .cmd = THERMAL_GENL_CMD_THRESHOLD_GET,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_THRESHOLD_ADD,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_THRESHOLD_DELETE,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
        {
                .cmd = THERMAL_GENL_CMD_THRESHOLD_FLUSH,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = thermal_genl_cmd_doit,
        },
};

static struct genl_family thermal_genl_family __ro_after_init = {
        .hdrsize        = 0,
        .name           = THERMAL_GENL_FAMILY_NAME,
        .version        = THERMAL_GENL_VERSION,
        .maxattr        = THERMAL_GENL_ATTR_MAX,
        .policy         = thermal_genl_policy,
        .bind           = thermal_genl_bind,
        .unbind         = thermal_genl_unbind,
        .small_ops      = thermal_genl_ops,
        .n_small_ops    = ARRAY_SIZE(thermal_genl_ops),
        .resv_start_op  = __THERMAL_GENL_CMD_MAX,
        .mcgrps         = thermal_genl_mcgrps,
        .n_mcgrps       = ARRAY_SIZE(thermal_genl_mcgrps),
};

int thermal_genl_register_notifier(struct notifier_block *nb)
{
        return blocking_notifier_chain_register(&thermal_genl_chain, nb);
}

int thermal_genl_unregister_notifier(struct notifier_block *nb)
{
        return blocking_notifier_chain_unregister(&thermal_genl_chain, nb);
}

int __init thermal_netlink_init(void)
{
        return genl_register_family(&thermal_genl_family);
}

void __init thermal_netlink_exit(void)
{
        genl_unregister_family(&thermal_genl_family);
}