[v4] PM: EM: Add netlink support for the energy model

[PATCH RESEND v4 05/10] PM: EM: Add a skeleton code for netlink notification

Posted by Changwoo Min 4 months, 3 weeks ago

Add a boilerplate code for netlink notification to register the new
protocol family. Also, initialize and register the netlink during booting.
The initialization is called at the postcore level, which is late enough
after the generic netlink is initialized.

Finally, update MAINTAINERS to include new files.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
---
 MAINTAINERS               |  2 +-
 kernel/power/Makefile     |  5 ++++-
 kernel/power/em_netlink.c | 35 +++++++++++++++++++++++++++++++++++
 kernel/power/em_netlink.h | 16 ++++++++++++++++
 4 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 kernel/power/em_netlink.c
 create mode 100644 kernel/power/em_netlink.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 0992029d271d..ba528836eac1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9034,7 +9034,7 @@ F:	include/linux/energy_model.h
 F:	Documentation/power/energy-model.rst
 F:	Documentation/netlink/specs/em.yaml
 F:	include/uapi/linux/energy_model.h
-F:	kernel/power/em_netlink_autogen.*
+F:	kernel/power/em_netlink*.*
 
 EPAPR HYPERVISOR BYTE CHANNEL DEVICE DRIVER
 M:	Laurentiu Tudor <laurentiu.tudor@nxp.com>
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 874ad834dc8d..284a760aade7 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -21,4 +21,7 @@ obj-$(CONFIG_PM_WAKELOCKS)	+= wakelock.o
 
 obj-$(CONFIG_MAGIC_SYSRQ)	+= poweroff.o
 
-obj-$(CONFIG_ENERGY_MODEL)	+= energy_model.o
+obj-$(CONFIG_ENERGY_MODEL)	+= em.o
+em-y				:= energy_model.o
+em-$(CONFIG_NET)		+= em_netlink_autogen.o em_netlink.o
+
diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
new file mode 100644
index 000000000000..f3fbfeff29a4
--- /dev/null
+++ b/kernel/power/em_netlink.c
@@ -0,0 +1,35 @@
+// 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"
+
+int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return -EOPNOTSUPP;
+}
+
+int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return -EOPNOTSUPP;
+}
+
+static int __init em_netlink_init(void)
+{
+	return genl_register_family(&em_nl_family);
+}
+postcore_initcall(em_netlink_init);
+
diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
new file mode 100644
index 000000000000..acd186c92d6b
--- /dev/null
+++ b/kernel/power/em_netlink.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *
+ * Generic netlink for energy model.
+ *
+ * Copyright (c) 2025 Valve Corporation.
+ * Author: Changwoo Min <changwoo@igalia.com>
+ */
+#ifndef _EM_NETLINK_H
+#define _EM_NETLINK_H
+
+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET)
+#else
+#endif
+
+#endif /* _EM_NETLINK_H */
-- 
2.51.0

Re: [PATCH RESEND v4 05/10] PM: EM: Add a skeleton code for netlink notification

Posted by Lukasz Luba 4 months ago


On 9/21/25 04:19, Changwoo Min wrote:
> Add a boilerplate code for netlink notification to register the new
> protocol family. Also, initialize and register the netlink during booting.
> The initialization is called at the postcore level, which is late enough
> after the generic netlink is initialized.
> 
> Finally, update MAINTAINERS to include new files.
> 
> Signed-off-by: Changwoo Min <changwoo@igalia.com>
> ---
>   MAINTAINERS               |  2 +-
>   kernel/power/Makefile     |  5 ++++-
>   kernel/power/em_netlink.c | 35 +++++++++++++++++++++++++++++++++++
>   kernel/power/em_netlink.h | 16 ++++++++++++++++
>   4 files changed, 56 insertions(+), 2 deletions(-)
>   create mode 100644 kernel/power/em_netlink.c
>   create mode 100644 kernel/power/em_netlink.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0992029d271d..ba528836eac1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9034,7 +9034,7 @@ F:	include/linux/energy_model.h
>   F:	Documentation/power/energy-model.rst
>   F:	Documentation/netlink/specs/em.yaml
>   F:	include/uapi/linux/energy_model.h
> -F:	kernel/power/em_netlink_autogen.*
> +F:	kernel/power/em_netlink*.*
>   
>   EPAPR HYPERVISOR BYTE CHANNEL DEVICE DRIVER
>   M:	Laurentiu Tudor <laurentiu.tudor@nxp.com>
> diff --git a/kernel/power/Makefile b/kernel/power/Makefile
> index 874ad834dc8d..284a760aade7 100644
> --- a/kernel/power/Makefile
> +++ b/kernel/power/Makefile
> @@ -21,4 +21,7 @@ obj-$(CONFIG_PM_WAKELOCKS)	+= wakelock.o
>   
>   obj-$(CONFIG_MAGIC_SYSRQ)	+= poweroff.o
>   
> -obj-$(CONFIG_ENERGY_MODEL)	+= energy_model.o
> +obj-$(CONFIG_ENERGY_MODEL)	+= em.o
> +em-y				:= energy_model.o
> +em-$(CONFIG_NET)		+= em_netlink_autogen.o em_netlink.o
> +
> diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
> new file mode 100644
> index 000000000000..f3fbfeff29a4
> --- /dev/null
> +++ b/kernel/power/em_netlink.c
> @@ -0,0 +1,35 @@
> +// 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"
> +
> +int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static int __init em_netlink_init(void)
> +{
> +	return genl_register_family(&em_nl_family);
> +}
> +postcore_initcall(em_netlink_init);
> +
> diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
> new file mode 100644
> index 000000000000..acd186c92d6b
> --- /dev/null
> +++ b/kernel/power/em_netlink.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + *
> + * Generic netlink for energy model.
> + *
> + * Copyright (c) 2025 Valve Corporation.
> + * Author: Changwoo Min <changwoo@igalia.com>
> + */
> +#ifndef _EM_NETLINK_H
> +#define _EM_NETLINK_H
> +
> +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET)
> +#else
> +#endif
> +
> +#endif /* _EM_NETLINK_H */

Actually, those declarations of functions from patch 3/10 can
live in this header. We would avoid creating more local headers
in such case.

Then the patch 3/10 would have to go after this patch when
this header is introduced.

Please ignore the comment in the patch 3/10 and try to
use this header. It is also logically linked to the
notifications, so belongs to such header IMHO.

Re: [PATCH RESEND v4 05/10] PM: EM: Add a skeleton code for netlink notification

Posted by Changwoo Min 3 months, 4 weeks ago


On 10/7/25 00:44, Lukasz Luba wrote:
> 
> 
> On 9/21/25 04:19, Changwoo Min wrote:
>> Add a boilerplate code for netlink notification to register the new
>> protocol family. Also, initialize and register the netlink during 
>> booting.
>> The initialization is called at the postcore level, which is late enough
>> after the generic netlink is initialized.
>>
>> Finally, update MAINTAINERS to include new files.
>>
>> Signed-off-by: Changwoo Min <changwoo@igalia.com>
>> ---
>>   MAINTAINERS               |  2 +-
>>   kernel/power/Makefile     |  5 ++++-
>>   kernel/power/em_netlink.c | 35 +++++++++++++++++++++++++++++++++++
>>   kernel/power/em_netlink.h | 16 ++++++++++++++++
>>   4 files changed, 56 insertions(+), 2 deletions(-)
>>   create mode 100644 kernel/power/em_netlink.c
>>   create mode 100644 kernel/power/em_netlink.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 0992029d271d..ba528836eac1 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -9034,7 +9034,7 @@ F:    include/linux/energy_model.h
>>   F:    Documentation/power/energy-model.rst
>>   F:    Documentation/netlink/specs/em.yaml
>>   F:    include/uapi/linux/energy_model.h
>> -F:    kernel/power/em_netlink_autogen.*
>> +F:    kernel/power/em_netlink*.*
>>   EPAPR HYPERVISOR BYTE CHANNEL DEVICE DRIVER
>>   M:    Laurentiu Tudor <laurentiu.tudor@nxp.com>
>> diff --git a/kernel/power/Makefile b/kernel/power/Makefile
>> index 874ad834dc8d..284a760aade7 100644
>> --- a/kernel/power/Makefile
>> +++ b/kernel/power/Makefile
>> @@ -21,4 +21,7 @@ obj-$(CONFIG_PM_WAKELOCKS)    += wakelock.o
>>   obj-$(CONFIG_MAGIC_SYSRQ)    += poweroff.o
>> -obj-$(CONFIG_ENERGY_MODEL)    += energy_model.o
>> +obj-$(CONFIG_ENERGY_MODEL)    += em.o
>> +em-y                := energy_model.o
>> +em-$(CONFIG_NET)        += em_netlink_autogen.o em_netlink.o
>> +
>> diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
>> new file mode 100644
>> index 000000000000..f3fbfeff29a4
>> --- /dev/null
>> +++ b/kernel/power/em_netlink.c
>> @@ -0,0 +1,35 @@
>> +// 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"
>> +
>> +int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
>> +{
>> +    return -EOPNOTSUPP;
>> +}
>> +
>> +int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info *info)
>> +{
>> +    return -EOPNOTSUPP;
>> +}
>> +
>> +static int __init em_netlink_init(void)
>> +{
>> +    return genl_register_family(&em_nl_family);
>> +}
>> +postcore_initcall(em_netlink_init);
>> +
>> diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
>> new file mode 100644
>> index 000000000000..acd186c92d6b
>> --- /dev/null
>> +++ b/kernel/power/em_netlink.h
>> @@ -0,0 +1,16 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + *
>> + * Generic netlink for energy model.
>> + *
>> + * Copyright (c) 2025 Valve Corporation.
>> + * Author: Changwoo Min <changwoo@igalia.com>
>> + */
>> +#ifndef _EM_NETLINK_H
>> +#define _EM_NETLINK_H
>> +
>> +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET)
>> +#else
>> +#endif
>> +
>> +#endif /* _EM_NETLINK_H */
> 
> Actually, those declarations of functions from patch 3/10 can
> live in this header. We would avoid creating more local headers
> in such case.

  That makes sense to me.

> 
> Then the patch 3/10 would have to go after this patch when
> this header is introduced.
> 
> Please ignore the comment in the patch 3/10 and try to
> use this header. It is also logically linked to the
> notifications, so belongs to such header IMHO.
>

Sure, after moving 3/10 after this, I will move the changes made in 3/10
to em_netlink.h. I will keep the implementation of
for_each_em_perf_domain() and em_perf_domain_get_by_id() in
energy_model.c since it it not ideal to expose em_pd_list_mutex, etc.
outside of energy_mode.c. And, this requires to include "em_netlink.h"
from energy_model.c.

Regards,
Changwoo Min

Re: [PATCH RESEND v4 05/10] PM: EM: Add a skeleton code for netlink notification

Posted by Lukasz Luba 3 months, 4 weeks ago


On 10/13/25 14:46, Changwoo Min wrote:
> 
> 
> On 10/7/25 00:44, Lukasz Luba wrote:
>>
>>
>> On 9/21/25 04:19, Changwoo Min wrote:
>>> Add a boilerplate code for netlink notification to register the new
>>> protocol family. Also, initialize and register the netlink during 
>>> booting.
>>> The initialization is called at the postcore level, which is late enough
>>> after the generic netlink is initialized.
>>>
>>> Finally, update MAINTAINERS to include new files.
>>>
>>> Signed-off-by: Changwoo Min <changwoo@igalia.com>
>>> ---
>>>   MAINTAINERS               |  2 +-
>>>   kernel/power/Makefile     |  5 ++++-
>>>   kernel/power/em_netlink.c | 35 +++++++++++++++++++++++++++++++++++
>>>   kernel/power/em_netlink.h | 16 ++++++++++++++++
>>>   4 files changed, 56 insertions(+), 2 deletions(-)
>>>   create mode 100644 kernel/power/em_netlink.c
>>>   create mode 100644 kernel/power/em_netlink.h
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 0992029d271d..ba528836eac1 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -9034,7 +9034,7 @@ F:    include/linux/energy_model.h
>>>   F:    Documentation/power/energy-model.rst
>>>   F:    Documentation/netlink/specs/em.yaml
>>>   F:    include/uapi/linux/energy_model.h
>>> -F:    kernel/power/em_netlink_autogen.*
>>> +F:    kernel/power/em_netlink*.*
>>>   EPAPR HYPERVISOR BYTE CHANNEL DEVICE DRIVER
>>>   M:    Laurentiu Tudor <laurentiu.tudor@nxp.com>
>>> diff --git a/kernel/power/Makefile b/kernel/power/Makefile
>>> index 874ad834dc8d..284a760aade7 100644
>>> --- a/kernel/power/Makefile
>>> +++ b/kernel/power/Makefile
>>> @@ -21,4 +21,7 @@ obj-$(CONFIG_PM_WAKELOCKS)    += wakelock.o
>>>   obj-$(CONFIG_MAGIC_SYSRQ)    += poweroff.o
>>> -obj-$(CONFIG_ENERGY_MODEL)    += energy_model.o
>>> +obj-$(CONFIG_ENERGY_MODEL)    += em.o
>>> +em-y                := energy_model.o
>>> +em-$(CONFIG_NET)        += em_netlink_autogen.o em_netlink.o
>>> +
>>> diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
>>> new file mode 100644
>>> index 000000000000..f3fbfeff29a4
>>> --- /dev/null
>>> +++ b/kernel/power/em_netlink.c
>>> @@ -0,0 +1,35 @@
>>> +// 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"
>>> +
>>> +int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>> +
>>> +int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info 
>>> *info)
>>> +{
>>> +    return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static int __init em_netlink_init(void)
>>> +{
>>> +    return genl_register_family(&em_nl_family);
>>> +}
>>> +postcore_initcall(em_netlink_init);
>>> +
>>> diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
>>> new file mode 100644
>>> index 000000000000..acd186c92d6b
>>> --- /dev/null
>>> +++ b/kernel/power/em_netlink.h
>>> @@ -0,0 +1,16 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +/*
>>> + *
>>> + * Generic netlink for energy model.
>>> + *
>>> + * Copyright (c) 2025 Valve Corporation.
>>> + * Author: Changwoo Min <changwoo@igalia.com>
>>> + */
>>> +#ifndef _EM_NETLINK_H
>>> +#define _EM_NETLINK_H
>>> +
>>> +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET)
>>> +#else
>>> +#endif
>>> +
>>> +#endif /* _EM_NETLINK_H */
>>
>> Actually, those declarations of functions from patch 3/10 can
>> live in this header. We would avoid creating more local headers
>> in such case.
> 
>   That makes sense to me.
> 
>>
>> Then the patch 3/10 would have to go after this patch when
>> this header is introduced.
>>
>> Please ignore the comment in the patch 3/10 and try to
>> use this header. It is also logically linked to the
>> notifications, so belongs to such header IMHO.
>>
> 
> Sure, after moving 3/10 after this, I will move the changes made in 3/10
> to em_netlink.h. I will keep the implementation of
> for_each_em_perf_domain() and em_perf_domain_get_by_id() in
> energy_model.c since it it not ideal to expose em_pd_list_mutex, etc.
> outside of energy_mode.c. And, this requires to include "em_netlink.h"
> from energy_model.c.
> 

Sounds good. These are only minor changes because it has nice shape
already.

I was able to test it last weekend and it works on my setup now.
I can see the messages coming in the user-space, so it should
work as designed.

Thank you Changwoo! Looking forward for your v5.

Regards,
Lukasz

Re: [PATCH RESEND v4 05/10] PM: EM: Add a skeleton code for netlink notification

Posted by Changwoo Min 3 months, 4 weeks ago


On 10/13/25 22:53, Lukasz Luba wrote:
> 
> 
> On 10/13/25 14:46, Changwoo Min wrote:
>>
>>
>> On 10/7/25 00:44, Lukasz Luba wrote:
>>>
>>>
>>> On 9/21/25 04:19, Changwoo Min wrote:
>>>> Add a boilerplate code for netlink notification to register the new
>>>> protocol family. Also, initialize and register the netlink during 
>>>> booting.
>>>> The initialization is called at the postcore level, which is late 
>>>> enough
>>>> after the generic netlink is initialized.
>>>>
>>>> Finally, update MAINTAINERS to include new files.
>>>>
>>>> Signed-off-by: Changwoo Min <changwoo@igalia.com>
>>>> ---
>>>>   MAINTAINERS               |  2 +-
>>>>   kernel/power/Makefile     |  5 ++++-
>>>>   kernel/power/em_netlink.c | 35 +++++++++++++++++++++++++++++++++++
>>>>   kernel/power/em_netlink.h | 16 ++++++++++++++++
>>>>   4 files changed, 56 insertions(+), 2 deletions(-)
>>>>   create mode 100644 kernel/power/em_netlink.c
>>>>   create mode 100644 kernel/power/em_netlink.h
>>>>
>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>> index 0992029d271d..ba528836eac1 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -9034,7 +9034,7 @@ F:    include/linux/energy_model.h
>>>>   F:    Documentation/power/energy-model.rst
>>>>   F:    Documentation/netlink/specs/em.yaml
>>>>   F:    include/uapi/linux/energy_model.h
>>>> -F:    kernel/power/em_netlink_autogen.*
>>>> +F:    kernel/power/em_netlink*.*
>>>>   EPAPR HYPERVISOR BYTE CHANNEL DEVICE DRIVER
>>>>   M:    Laurentiu Tudor <laurentiu.tudor@nxp.com>
>>>> diff --git a/kernel/power/Makefile b/kernel/power/Makefile
>>>> index 874ad834dc8d..284a760aade7 100644
>>>> --- a/kernel/power/Makefile
>>>> +++ b/kernel/power/Makefile
>>>> @@ -21,4 +21,7 @@ obj-$(CONFIG_PM_WAKELOCKS)    += wakelock.o
>>>>   obj-$(CONFIG_MAGIC_SYSRQ)    += poweroff.o
>>>> -obj-$(CONFIG_ENERGY_MODEL)    += energy_model.o
>>>> +obj-$(CONFIG_ENERGY_MODEL)    += em.o
>>>> +em-y                := energy_model.o
>>>> +em-$(CONFIG_NET)        += em_netlink_autogen.o em_netlink.o
>>>> +
>>>> diff --git a/kernel/power/em_netlink.c b/kernel/power/em_netlink.c
>>>> new file mode 100644
>>>> index 000000000000..f3fbfeff29a4
>>>> --- /dev/null
>>>> +++ b/kernel/power/em_netlink.c
>>>> @@ -0,0 +1,35 @@
>>>> +// 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"
>>>> +
>>>> +int em_nl_get_pds_doit(struct sk_buff *skb, struct genl_info *info)
>>>> +{
>>>> +    return -EOPNOTSUPP;
>>>> +}
>>>> +
>>>> +int em_nl_get_pd_table_doit(struct sk_buff *skb, struct genl_info 
>>>> *info)
>>>> +{
>>>> +    return -EOPNOTSUPP;
>>>> +}
>>>> +
>>>> +static int __init em_netlink_init(void)
>>>> +{
>>>> +    return genl_register_family(&em_nl_family);
>>>> +}
>>>> +postcore_initcall(em_netlink_init);
>>>> +
>>>> diff --git a/kernel/power/em_netlink.h b/kernel/power/em_netlink.h
>>>> new file mode 100644
>>>> index 000000000000..acd186c92d6b
>>>> --- /dev/null
>>>> +++ b/kernel/power/em_netlink.h
>>>> @@ -0,0 +1,16 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/*
>>>> + *
>>>> + * Generic netlink for energy model.
>>>> + *
>>>> + * Copyright (c) 2025 Valve Corporation.
>>>> + * Author: Changwoo Min <changwoo@igalia.com>
>>>> + */
>>>> +#ifndef _EM_NETLINK_H
>>>> +#define _EM_NETLINK_H
>>>> +
>>>> +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_NET)
>>>> +#else
>>>> +#endif
>>>> +
>>>> +#endif /* _EM_NETLINK_H */
>>>
>>> Actually, those declarations of functions from patch 3/10 can
>>> live in this header. We would avoid creating more local headers
>>> in such case.
>>
>>   That makes sense to me.
>>
>>>
>>> Then the patch 3/10 would have to go after this patch when
>>> this header is introduced.
>>>
>>> Please ignore the comment in the patch 3/10 and try to
>>> use this header. It is also logically linked to the
>>> notifications, so belongs to such header IMHO.
>>>
>>
>> Sure, after moving 3/10 after this, I will move the changes made in 3/10
>> to em_netlink.h. I will keep the implementation of
>> for_each_em_perf_domain() and em_perf_domain_get_by_id() in
>> energy_model.c since it it not ideal to expose em_pd_list_mutex, etc.
>> outside of energy_mode.c. And, this requires to include "em_netlink.h"
>> from energy_model.c.
>>
> 
> Sounds good. These are only minor changes because it has nice shape
> already.
> 
> I was able to test it last weekend and it works on my setup now.
> I can see the messages coming in the user-space, so it should
> work as designed.
> 
> Thank you Changwoo! Looking forward for your v5.

Thank you Lukasz for testing. I will send v5 soon after final testing.

Regards,
Changwoo Min