On 10/14/25 01:10, Changwoo Min wrote:
> Add the event notification infrastructure and implement the event
> notification for when a performance domain is deleted (EM_CMD_PD_DELETED).
>
> The event contains the ID of the performance domain (EM_A_PD_TABLE_PD_ID)
> so the userspace can identify the changed performance domain for further
> processing.
>
> Signed-off-by: Changwoo Min <changwoo@igalia.com>
> ---
> kernel/power/em_netlink.c | 46 +++++++++++++++++++++++++++++++++++++++
> kernel/power/em_netlink.h | 3 +++
> 2 files changed, 49 insertions(+)
>
> diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
> index 2addc143401b..90ae6f1c9c9a 100644
> --- a/kernel/power/em_netlink.c
> +++ b/kernel/power/em_netlink.c
> @@ -213,6 +213,52 @@ int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)
> return ret;
> }
>
> +
> +/**************************** Event encoding *********************************/
> +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;
> + int ret = -EMSGSIZE;
> + 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)) {
> + ret = -EMSGSIZE;
> + 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);
> diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
> index 8114b018c73b..d56e5865e1ed 100644
> --- a/kernel/power/em_netlink.h
> +++ b/kernel/power/em_netlink.h
> @@ -13,6 +13,7 @@
> int for_each_em_perf_domain(int (*cb)(struct em_perf_domain*, void *),
> void *data);
> struct em_perf_domain *em_perf_domain_get_by_id(int id);
> +void em_notify_pd_deleted(const struct em_perf_domain *pd);
> #else
> static inline
> int for_each_em_perf_domain(int (*cb)(struct em_perf_domain*, void *),
> @@ -25,6 +26,8 @@ struct em_perf_domain *em_perf_domain_get_by_id(int id)
> {
> return NULL;
> }
> +
> +static inline void em_notify_pd_deleted(const struct em_perf_domain *pd) {}
> #endif
>
> #endif /* _EM_NETLINK_H */
LGTM,
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>