Commit d8eef045 authored by Changwoo Min's avatar Changwoo Min Committed by Rafael J. Wysocki
Browse files

PM: EM: Implement em_nl_get_pds_doit() 



When a userspace requests EM_CMD_GET_PDS, the kernel responds with
information on all performance domains. The message format of the
response is as follows:

EM_A_PDS_PD (NLA_NESTED)*
    EM_A_PD_PD_ID (NLA_U32)
    EM_A_PD_FLAGS (NLA_U64)
    EM_A_PD_CPUS (NLA_STRING)

where EM_A_PDS_PD can be repeated as many times as there are performance
domains, and EM_A_PD_CPUS is a hexadecimal string representing a CPU
bitmask.

Signed-off-by: default avatarChangwoo Min <changwoo@igalia.com>
Reviewed-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-7-changwoo@igalia.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7928339c

kernel/power/em_netlink.c

+81 −1
Original line number Diff line number Diff line
@@ -17,9 +17,89 @@ 
#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)

{

	return -EOPNOTSUPP;

	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;

}



int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)