PM: EM: Add em.yaml and autogen files

Add a generic netlink spec in YAML format and autogenerate boilerplate
code using ynl-regen.sh to introduce a generic netlink for the energy
model. It allows a userspace program to read the performance domain and
its energy model. It notifies the userspace program when a performance
domain is created or deleted or its energy model is updated through a
multicast interface.

Specifically, it supports two commands:
  - EM_CMD_GET_PDS: Get the list of information for all performance
    domains.
  - EM_CMD_GET_PD_TABLE: Get the energy model table of a performance
    domain.

Also, it supports three notification events:
  - EM_CMD_PD_CREATED: When a performance domain is created.
  - EM_CMD_PD_DELETED: When a performance domain is deleted.
  - EM_CMD_PD_UPDATED: When the energy model table of a performance domain
    is updated.

Finally, update MAINTAINERS to include new files.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20251020220914.320832-4-changwoo@igalia.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/Documentation/netlink/specs/em.yaml b/Documentation/netlink/specs/em.yaml
new file mode 100644
index 000000000000..9905ca482325
--- /dev/null
+++ b/Documentation/netlink/specs/em.yaml
@@ -0,0 +1,113 @@
+# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+
+name: em
+
+doc: |
+  Energy model netlink interface to notify its changes.
+
+protocol: genetlink
+
+uapi-header: linux/energy_model.h
+
+attribute-sets:
+  -
+    name: pds
+    attributes:
+      -
+        name: pd
+        type: nest
+        nested-attributes: pd
+        multi-attr: true
+  -
+    name: pd
+    attributes:
+      -
+        name: pad
+        type: pad
+      -
+        name: pd-id
+        type: u32
+      -
+        name: flags
+        type: u64
+      -
+        name: cpus
+        type: string
+  -
+    name: pd-table
+    attributes:
+      -
+        name: pd-id
+        type: u32
+      -
+        name: ps
+        type: nest
+        nested-attributes: ps
+        multi-attr: true
+  -
+    name: ps
+    attributes:
+      -
+        name: pad
+        type: pad
+      -
+        name: performance
+        type: u64
+      -
+        name: frequency
+        type: u64
+      -
+        name: power
+        type: u64
+      -
+        name: cost
+        type: u64
+      -
+        name: flags
+        type: u64
+
+operations:
+  list:
+    -
+      name: get-pds
+      attribute-set: pds
+      doc: Get the list of information for all performance domains.
+      do:
+        reply:
+          attributes:
+            - pd
+    -
+      name: get-pd-table
+      attribute-set: pd-table
+      doc: Get the energy model table of a performance domain.
+      do:
+        request:
+          attributes:
+            - pd-id
+        reply:
+          attributes:
+            - pd-id
+            - ps
+    -
+      name: pd-created
+      doc: A performance domain is created.
+      notify: get-pd-table
+      mcgrp: event
+    -
+      name: pd-updated
+      doc: A performance domain is updated.
+      notify: get-pd-table
+      mcgrp: event
+    -
+      name: pd-deleted
+      doc: A performance domain is deleted.
+      attribute-set: pd-table
+      event:
+        attributes:
+            - pd-id
+      mcgrp: event
+
+mcast-groups:
+  list:
+    -
+      name: event