Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
---
 .../networking/devlink/devlink-region.rst     |  9 +++-
 include/net/devlink.h                         |  7 +++
 include/uapi/linux/devlink.h                  |  2 +
 net/core/devlink.c                            | 46 +++++++++++++++++++
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/devlink/devlink-region.rst b/Documentation/networking/devlink/devlink-region.rst
index 1a7683e7acb2..262249e6c3fc 100644
--- a/Documentation/networking/devlink/devlink-region.rst
+++ b/Documentation/networking/devlink/devlink-region.rst

@@ -20,6 +20,11 @@ address regions that are otherwise inaccessible to the user.
 Regions may also be used to provide an additional way to debug complex error
 states, but see also :doc:`devlink-health`
 
+Regions may optionally support capturing a snapshot on demand via the
+``DEVLINK_CMD_REGION_TAKE_SNAPSHOT`` netlink message. A driver wishing to
+allow requested snapshots must implement the ``.snapshot`` callback for the
+region in its ``devlink_region_ops`` structure.
+
 example usage
 -------------
 

@@ -40,8 +45,8 @@ example usage
     # Delete a snapshot using:
     $ devlink region del pci/0000:00:05.0/cr-space snapshot 1
 
-    # Trigger (request) a snapshot be taken:
-    $ devlink region trigger pci/0000:00:05.0/cr-space
+    # Request an immediate snapshot, if supported by the region
+    $ devlink region snapshot pci/0000:00:05.0/cr-space
 
     # Dump a snapshot:
     $ devlink region dump pci/0000:00:05.0/fw-health snapshot 1

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 4a0baa6903cb..63e954241404 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h

@@ -498,9 +498,16 @@ typedef void devlink_snapshot_data_dest_t(const void *data);
 /**
  * struct devlink_region_ops - Region operations
  * @name: region name
+ * @snapshot: callback to request an immediate snapshot. On success,
+ *            the data and destructor variables must be updated. The function
+ *            will be called while the devlink instance lock is held.
  */
 struct devlink_region_ops {
 	const char *name;
+	int (*snapshot)(struct devlink *devlink,
+			struct netlink_ext_ack *extack,
+			u8 **data,
+			devlink_snapshot_data_dest_t **destructor);
 };
 
 struct devlink_fmsg;

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index ae37fd4d194a..46643c4320b9 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h

@@ -117,6 +117,8 @@ enum devlink_command {
 	DEVLINK_CMD_TRAP_GROUP_NEW,
 	DEVLINK_CMD_TRAP_GROUP_DEL,
 
+	DEVLINK_CMD_REGION_TAKE_SNAPSHOT,
+
 	/* add new commands above here */
 	__DEVLINK_CMD_MAX,
 	DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1

diff --git a/net/core/devlink.c b/net/core/devlink.c
index faf4f4c5c539..574008c536fa 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c

@@ -4109,6 +4109,45 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 	return err;
 }
 
+static int devlink_nl_cmd_region_take_snapshot(struct sk_buff *skb,
+					       struct genl_info *info)
+{
+	struct devlink *devlink = info->user_ptr[0];
+	devlink_snapshot_data_dest_t *destructor;
+	struct devlink_region *region;
+	const char *region_name;
+	u32 snapshot_id;
+	u8 *data;
+	int err;
+
+	if (!info->attrs[DEVLINK_ATTR_REGION_NAME]) {
+		NL_SET_ERR_MSG_MOD(info->extack, "No region name provided");
+		return -EINVAL;
+	}
+
+	region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
+	region = devlink_region_get_by_name(devlink, region_name);
+	if (!region) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "The requested region does not exist");
+		return -EINVAL;
+	}
+
+	if (!region->ops->snapshot) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "The requested region does not support taking an immediate snapshot");
+		return -EOPNOTSUPP;
+	}
+
+	err = region->ops->snapshot(devlink, info->extack, &data, &destructor);
+	if (err)
+		return err;
+
+	snapshot_id = devlink_region_snapshot_id_get_locked(devlink);
+	return devlink_region_snapshot_create_locked(region, data, snapshot_id,
+						     destructor);
+}
+
 struct devlink_info_req {
 	struct sk_buff *msg;
 };

@@ -6249,6 +6288,13 @@ static const struct genl_ops devlink_nl_ops[] = {
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
 	},
+	{
+		.cmd = DEVLINK_CMD_REGION_TAKE_SNAPSHOT,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = devlink_nl_cmd_region_take_snapshot,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+	},
 	{
 		.cmd = DEVLINK_CMD_INFO_GET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,