devlink: introduce line card device info infrastructure

Extend the line card info message with information (e.g., FW version)
about devices found on the line card.

Example:
$ devlink lc info pci/0000:01:00.0 lc 8
pci/0000:01:00.0:
  lc 8
    versions:
        fixed:
          hw.revision 0
        running:
          ini.version 4
    devices:
      device 0
        versions:
            running:
              fw 19.2010.1310
      device 1
        versions:
            running:
              fw 19.2010.1310
      device 2
        versions:
            running:
              fw 19.2010.1310
      device 3
        versions:
            running:
              fw 19.2010.1310
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/devlink-linecard.rst

@@ -14,7 +14,7 @@ system. Following operations are provided:
   * Get a list of supported line card types.
   * Provision of a slot with specific line card type.
   * Get and monitor of line card state and its change.
-  * Get information about line card versions.
+  * Get information about line card versions and devices.
 
 Line card according to the type may contain one or more gearboxes
 to mux the lanes with certain speed to multiple ports with lanes

include/net/devlink.h

@@ -151,6 +151,7 @@ struct devlink_port_new_attrs {
 };
 
 struct devlink_info_req;
+struct devlink_linecard_device;
 
 /**
  * struct devlink_linecard_ops - Linecard operations
@@ -171,6 +172,7 @@ struct devlink_info_req;
  * @types_count: callback to get number of supported types
  * @types_get: callback to get next type in list
  * @info_get: callback to get linecard info
+ * @device_info_get: callback to get linecard device info
  */
 struct devlink_linecard_ops {
 	int (*provision)(struct devlink_linecard *linecard, void *priv,
@@ -188,6 +190,9 @@ struct devlink_linecard_ops {
 	int (*info_get)(struct devlink_linecard *linecard, void *priv,
 			struct devlink_info_req *req,
 			struct netlink_ext_ack *extack);
+	int (*device_info_get)(struct devlink_linecard_device *device,
+			       void *priv, struct devlink_info_req *req,
+			       struct netlink_ext_ack *extack);
 };
 
 struct devlink_sb_pool_info {
@@ -1583,10 +1588,9 @@ struct devlink_linecard *
 devlink_linecard_create(struct devlink *devlink, unsigned int linecard_index,
 			const struct devlink_linecard_ops *ops, void *priv);
 void devlink_linecard_destroy(struct devlink_linecard *linecard);
-struct devlink_linecard_device;
 struct devlink_linecard_device *
 devlink_linecard_device_create(struct devlink_linecard *linecard,
-			       unsigned int device_index);
+			       unsigned int device_index, void *priv);
 void
 devlink_linecard_device_destroy(struct devlink_linecard *linecard,
 				struct devlink_linecard_device *linecard_device);

net/core/devlink.c

@@ -2062,6 +2062,7 @@ struct devlink_linecard_type {
 struct devlink_linecard_device {
 	struct list_head list;
 	unsigned int index;
+	void *priv;
 };
 
 static int
@@ -2428,6 +2429,68 @@ struct devlink_info_req {
 	struct sk_buff *msg;
 };
 
+static int
+devlink_nl_linecard_device_info_fill(struct sk_buff *msg,
+				     struct devlink_linecard *linecard,
+				     struct devlink_linecard_device *linecard_device,
+				     struct netlink_ext_ack *extack)
+{
+	struct nlattr *attr;
+
+	attr = nla_nest_start(msg, DEVLINK_ATTR_LINECARD_DEVICE);
+	if (!attr)
+		return -EMSGSIZE;
+	if (nla_put_u32(msg, DEVLINK_ATTR_LINECARD_DEVICE_INDEX,
+			linecard_device->index)) {
+		nla_nest_cancel(msg, attr);
+		return -EMSGSIZE;
+	}
+	if (linecard->ops->device_info_get) {
+		struct devlink_info_req req;
+		int err;
+
+		req.msg = msg;
+		err = linecard->ops->device_info_get(linecard_device,
+						     linecard_device->priv,
+						     &req, extack);
+		if (err) {
+			nla_nest_cancel(msg, attr);
+			return err;
+		}
+	}
+	nla_nest_end(msg, attr);
+
+	return 0;
+}
+
+static int devlink_nl_linecard_devices_info_fill(struct sk_buff *msg,
+						 struct devlink_linecard *linecard,
+						 struct netlink_ext_ack *extack)
+{
+	struct devlink_linecard_device *linecard_device;
+	struct nlattr *attr;
+	int err;
+
+	if (list_empty(&linecard->device_list))
+		return 0;
+
+	attr = nla_nest_start(msg, DEVLINK_ATTR_LINECARD_DEVICE_LIST);
+	if (!attr)
+		return -EMSGSIZE;
+	list_for_each_entry(linecard_device, &linecard->device_list, list) {
+		err = devlink_nl_linecard_device_info_fill(msg, linecard,
+							   linecard_device,
+							   extack);
+		if (err) {
+			nla_nest_cancel(msg, attr);
+			return err;
+		}
+	}
+	nla_nest_end(msg, attr);
+
+	return 0;
+}
+
 static int
 devlink_nl_linecard_info_fill(struct sk_buff *msg, struct devlink *devlink,
 			      struct devlink_linecard *linecard,
@@ -2453,6 +2516,10 @@ devlink_nl_linecard_info_fill(struct sk_buff *msg, struct devlink *devlink,
 	if (err)
 		goto nla_put_failure;
 
+	err = devlink_nl_linecard_devices_info_fill(msg, linecard, extack);
+	if (err)
+		goto nla_put_failure;
+
 	genlmsg_end(msg, hdr);
 	return 0;
 
@@ -10483,12 +10550,13 @@ EXPORT_SYMBOL_GPL(devlink_linecard_destroy);
  *
  *	@linecard: devlink linecard
  *	@device_index: index of the linecard device
+ *	@priv: user priv pointer
  *
  *	Return: Line card device structure or an ERR_PTR() encoded error code.
  */
 struct devlink_linecard_device *
 devlink_linecard_device_create(struct devlink_linecard *linecard,
-			       unsigned int device_index)
+			       unsigned int device_index, void *priv)
 {
 	struct devlink_linecard_device *linecard_device;
 
@@ -10496,6 +10564,7 @@ devlink_linecard_device_create(struct devlink_linecard *linecard,
 	if (!linecard_device)
 		return ERR_PTR(-ENOMEM);
 	linecard_device->index = device_index;
+	linecard_device->priv = priv;
 	mutex_lock(&linecard->state_lock);
 	list_add_tail(&linecard_device->list, &linecard->device_list);
 	devlink_linecard_notify(linecard, DEVLINK_CMD_LINECARD_NEW);