From cf580ad490514cca4abbfef710fe4099738abfbd Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> Date: Fri, 23 Feb 2024 16:59:40 +0100 Subject: [PATCH] thermal: netlink: Add genetlink bind/unbind notifications Introduce a new feature to the thermal netlink framework, enabling the registration of sub drivers to receive events via a notifier mechanism. Specifically, implement genetlink family bind and unbind callbacks to send BIND and UNBIND events. The primary purpose of this enhancement is to facilitate the tracking of user-space consumers by the Intel HFI driver. By leveraging these notifications, the driver can determine when consumers are present or absent. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- drivers/thermal/thermal_netlink.c | 40 +++++++++++++++++++++++++++---- drivers/thermal/thermal_netlink.h | 26 ++++++++++++++++++++ 2 files changed, 61 insertions(+), 5 deletions(-) diff --git a/drivers/thermal/thermal_netlink.c b/drivers/thermal/thermal_netlink.c index 76a231a29654..d407130563e5 100644 --- a/drivers/thermal/thermal_netlink.c +++ b/drivers/thermal/thermal_netlink.c @@ -7,17 +7,13 @@ * Generic netlink for thermal management framework */ #include <linux/module.h> +#include <linux/notifier.h> #include <linux/kernel.h> #include <net/genetlink.h> #include <uapi/linux/thermal.h> #include "thermal_core.h" -enum thermal_genl_multicast_groups { - THERMAL_GENL_SAMPLING_GROUP = 0, - THERMAL_GENL_EVENT_GROUP = 1, -}; - 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, }, @@ -75,6 +71,7 @@ struct param { typedef int (*cb_t)(struct param *); static struct genl_family thermal_gnl_family; +static BLOCKING_NOTIFIER_HEAD(thermal_genl_chain); static int thermal_group_has_listeners(enum thermal_genl_multicast_groups group) { @@ -645,6 +642,27 @@ out_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, @@ -679,6 +697,8 @@ static struct genl_family thermal_gnl_family __ro_after_init = { .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_CDEV_GET + 1, @@ -686,6 +706,16 @@ static struct genl_family thermal_gnl_family __ro_after_init = { .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_gnl_family); diff --git a/drivers/thermal/thermal_netlink.h b/drivers/thermal/thermal_netlink.h index 93a927e144d5..e01221e8816b 100644 --- a/drivers/thermal/thermal_netlink.h +++ b/drivers/thermal/thermal_netlink.h @@ -10,6 +10,19 @@ struct thermal_genl_cpu_caps { int efficiency; }; +enum thermal_genl_multicast_groups { + THERMAL_GENL_SAMPLING_GROUP = 0, + THERMAL_GENL_EVENT_GROUP = 1, + THERMAL_GENL_MAX_GROUP = THERMAL_GENL_EVENT_GROUP, +}; + +#define THERMAL_NOTIFY_BIND 0 +#define THERMAL_NOTIFY_UNBIND 1 + +struct thermal_genl_notify { + int mcgrp; +}; + struct thermal_zone_device; struct thermal_trip; struct thermal_cooling_device; @@ -18,6 +31,9 @@ struct thermal_cooling_device; #ifdef CONFIG_THERMAL_NETLINK int __init thermal_netlink_init(void); void __init thermal_netlink_exit(void); +int thermal_genl_register_notifier(struct notifier_block *nb); +int thermal_genl_unregister_notifier(struct notifier_block *nb); + int thermal_notify_tz_create(const struct thermal_zone_device *tz); int thermal_notify_tz_delete(const struct thermal_zone_device *tz); int thermal_notify_tz_enable(const struct thermal_zone_device *tz); @@ -48,6 +64,16 @@ static inline int thermal_notify_tz_create(const struct thermal_zone_device *tz) return 0; } +static inline int thermal_genl_register_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline int thermal_genl_unregister_notifier(struct notifier_block *nb) +{ + return 0; +} + static inline int thermal_notify_tz_delete(const struct thermal_zone_device *tz) { return 0;