1 files changed, 308 insertions, 0 deletions
diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
new file mode 100644
index 000000000000..4b85da138a06
--- /dev/null
+++ b/kernel/power/em_netlink.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Generic netlink for energy model.
+ *
+ * Copyright (c) 2025 Valve Corporation.
+ * Author: Changwoo Min <changwoo@igalia.com>
+ */
+
+#define pr_fmt(fmt) "energy_model: " fmt
+
+#include <linux/energy_model.h>
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <uapi/linux/energy_model.h>
+
+#include "em_netlink.h"
+#include "em_netlink_autogen.h"
+
+#define EM_A_PD_CPUS_LEN		256
+
+/*************************** Command encoding ********************************/
+static int __em_nl_get_pd_size(struct em_perf_domain *pd, void *data)
+{
+	char cpus_buf[EM_A_PD_CPUS_LEN];
+	int *tot_msg_sz = data;
+	int msg_sz, cpus_sz;
+
+	cpus_sz = snprintf(cpus_buf, sizeof(cpus_buf), "%*pb",
+			   cpumask_pr_args(to_cpumask(pd->cpus)));
+
+	msg_sz = nla_total_size(0) +			/* EM_A_PDS_PD */
+		 nla_total_size(sizeof(u32)) +		/* EM_A_PD_PD_ID */
+		 nla_total_size_64bit(sizeof(u64)) +	/* EM_A_PD_FLAGS */
+		 nla_total_size(cpus_sz);		/* EM_A_PD_CPUS */
+
+	*tot_msg_sz += nlmsg_total_size(genlmsg_msg_size(msg_sz));
+	return 0;
+}
+
+static int __em_nl_get_pd(struct em_perf_domain *pd, void *data)
+{
+	char cpus_buf[EM_A_PD_CPUS_LEN];
+	struct sk_buff *msg = data;
+	struct nlattr *entry;
+
+	entry = nla_nest_start(msg, EM_A_PDS_PD);
+	if (!entry)
+		goto out_cancel_nest;
+
+	if (nla_put_u32(msg, EM_A_PD_PD_ID, pd->id))
+		goto out_cancel_nest;
+
+	if (nla_put_u64_64bit(msg, EM_A_PD_FLAGS, pd->flags, EM_A_PD_PAD))
+		goto out_cancel_nest;
+
+	snprintf(cpus_buf, sizeof(cpus_buf), "%*pb",
+		 cpumask_pr_args(to_cpumask(pd->cpus)));
+	if (nla_put_string(msg, EM_A_PD_CPUS, cpus_buf))
+		goto out_cancel_nest;
+
+	nla_nest_end(msg, entry);
+
+	return 0;
+
+out_cancel_nest:
+	nla_nest_cancel(msg, entry);
+
+	return -EMSGSIZE;
+}
+
+int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	void *hdr;
+	int cmd = info->genlhdr->cmd;
+	int ret = -EMSGSIZE, msg_sz = 0;
+
+	for_each_em_perf_domain(__em_nl_get_pd_size, &msg_sz);
+
+	msg = genlmsg_new(msg_sz, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put_reply(msg, info, &em_nl_family, 0, cmd);
+	if (!hdr)
+		goto out_free_msg;
+
+	ret = for_each_em_perf_domain(__em_nl_get_pd, msg);
+	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 struct em_perf_domain *__em_nl_get_pd_table_id(struct nlattr **attrs)
+{
+	struct em_perf_domain *pd;
+	int id;
+
+	if (!attrs[EM_A_PD_TABLE_PD_ID])
+		return NULL;
+
+	id = nla_get_u32(attrs[EM_A_PD_TABLE_PD_ID]);
+	pd = em_perf_domain_get_by_id(id);
+	return pd;
+}
+
+static int __em_nl_get_pd_table_size(const struct em_perf_domain *pd)
+{
+	int id_sz, ps_sz;
+
+	id_sz = nla_total_size(sizeof(u32));		/* EM_A_PD_TABLE_PD_ID */
+	ps_sz = nla_total_size(0) +			/* EM_A_PD_TABLE_PS */
+		nla_total_size_64bit(sizeof(u64)) +	/* EM_A_PS_PERFORMANCE */
+		nla_total_size_64bit(sizeof(u64)) +	/* EM_A_PS_FREQUENCY */
+		nla_total_size_64bit(sizeof(u64)) +	/* EM_A_PS_POWER */
+		nla_total_size_64bit(sizeof(u64)) +	/* EM_A_PS_COST */
+		nla_total_size_64bit(sizeof(u64));	/* EM_A_PS_FLAGS */
+	ps_sz *= pd->nr_perf_states;
+
+	return nlmsg_total_size(genlmsg_msg_size(id_sz + ps_sz));
+}
+
+static int __em_nl_get_pd_table(struct sk_buff *msg, const struct em_perf_domain *pd)
+{
+	struct em_perf_state *table, *ps;
+	struct nlattr *entry;
+	int i;
+
+	if (nla_put_u32(msg, EM_A_PD_TABLE_PD_ID, pd->id))
+		goto out_err;
+
+	rcu_read_lock();
+	table = em_perf_state_from_pd((struct em_perf_domain *)pd);
+
+	for (i = 0; i < pd->nr_perf_states; i++) {
+		ps = &table[i];
+
+		entry = nla_nest_start(msg, EM_A_PD_TABLE_PS);
+		if (!entry)
+			goto out_unlock_ps;
+
+		if (nla_put_u64_64bit(msg, EM_A_PS_PERFORMANCE,
+				      ps->performance, EM_A_PS_PAD))
+			goto out_cancel_ps_nest;
+		if (nla_put_u64_64bit(msg, EM_A_PS_FREQUENCY,
+				      ps->frequency, EM_A_PS_PAD))
+			goto out_cancel_ps_nest;
+		if (nla_put_u64_64bit(msg, EM_A_PS_POWER,
+				      ps->power, EM_A_PS_PAD))
+			goto out_cancel_ps_nest;
+		if (nla_put_u64_64bit(msg, EM_A_PS_COST,
+				      ps->cost, EM_A_PS_PAD))
+			goto out_cancel_ps_nest;
+		if (nla_put_u64_64bit(msg, EM_A_PS_FLAGS,
+				      ps->flags, EM_A_PS_PAD))
+			goto out_cancel_ps_nest;
+
+		nla_nest_end(msg, entry);
+	}
+	rcu_read_unlock();
+	return 0;
+
+out_cancel_ps_nest:
+	nla_nest_cancel(msg, entry);
+out_unlock_ps:
+	rcu_read_unlock();
+out_err:
+	return -EMSGSIZE;
+}
+
+int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	int cmd = info->genlhdr->cmd;
+	int msg_sz, ret = -EMSGSIZE;
+	struct em_perf_domain *pd;
+	struct sk_buff *msg;
+	void *hdr;
+
+	pd = __em_nl_get_pd_table_id(info->attrs);
+	if (!pd)
+		return -EINVAL;
+
+	msg_sz = __em_nl_get_pd_table_size(pd);
+
+	msg = genlmsg_new(msg_sz, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put_reply(msg, info, &em_nl_family, 0, cmd);
+	if (!hdr)
+		goto out_free_msg;
+
+	ret = __em_nl_get_pd_table(msg, pd);
+	if (ret)
+		goto out_free_msg;
+
+	genlmsg_end(msg, hdr);
+	return genlmsg_reply(msg, info);
+
+out_free_msg:
+	nlmsg_free(msg);
+	return ret;
+}
+
+
+/**************************** Event encoding *********************************/
+static void __em_notify_pd_table(const struct em_perf_domain *pd, int ntf_type)
+{
+	struct sk_buff *msg;
+	int msg_sz, ret = -EMSGSIZE;
+	void *hdr;
+
+	if (!genl_has_listeners(&em_nl_family, &init_net, EM_NLGRP_EVENT))
+		return;
+
+	msg_sz = __em_nl_get_pd_table_size(pd);
+
+	msg = genlmsg_new(msg_sz, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	hdr = genlmsg_put(msg, 0, 0, &em_nl_family, 0, ntf_type);
+	if (!hdr)
+		goto out_free_msg;
+
+	ret = __em_nl_get_pd_table(msg, pd);
+	if (ret)
+		goto out_free_msg;
+
+	genlmsg_end(msg, hdr);
+
+	genlmsg_multicast(&em_nl_family, msg, 0, EM_NLGRP_EVENT, GFP_KERNEL);
+
+	return;
+
+out_free_msg:
+	nlmsg_free(msg);
+	return;
+}
+
+void em_notify_pd_created(const struct em_perf_domain *pd)
+{
+	__em_notify_pd_table(pd, EM_CMD_PD_CREATED);
+}
+
+void em_notify_pd_updated(const struct em_perf_domain *pd)
+{
+	__em_notify_pd_table(pd, EM_CMD_PD_UPDATED);
+}
+
+static int __em_notify_pd_deleted_size(const struct em_perf_domain *pd)
+{
+	int id_sz = nla_total_size(sizeof(u32)); /* EM_A_PD_TABLE_PD_ID */
+
+	return nlmsg_total_size(genlmsg_msg_size(id_sz));
+}
+
+void em_notify_pd_deleted(const struct em_perf_domain *pd)
+{
+	struct sk_buff *msg;
+	void *hdr;
+	int msg_sz;
+
+	if (!genl_has_listeners(&em_nl_family, &init_net, EM_NLGRP_EVENT))
+		return;
+
+	msg_sz = __em_notify_pd_deleted_size(pd);
+
+	msg = genlmsg_new(msg_sz, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	hdr = genlmsg_put(msg, 0, 0, &em_nl_family, 0, EM_CMD_PD_DELETED);
+	if (!hdr)
+		goto out_free_msg;
+
+	if (nla_put_u32(msg, EM_A_PD_TABLE_PD_ID, pd->id)) {
+		goto out_free_msg;
+	}
+
+	genlmsg_end(msg, hdr);
+
+	genlmsg_multicast(&em_nl_family, msg, 0, EM_NLGRP_EVENT, GFP_KERNEL);
+
+	return;
+
+out_free_msg:
+	nlmsg_free(msg);
+	return;
+}
+
+/**************************** Initialization *********************************/
+static int __init em_netlink_init(void)
+{
+	return genl_register_family(&em_nl_family);
+}
+postcore_initcall(em_netlink_init);