path: 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,