Merge branch 'devlink-add-device-driver-information-API'

Jakub Kicinski says:

====================
devlink: add device (driver) information API

fw_version field in ethtool -i does not suit modern needs with 31
characters being quite limiting on more complex systems.  There is
also no distinction between the running and flashed versions of
the firmware.

Since the driver information pertains to the entire device, rather
than a particular netdev, it seems wise to move it do devlink, at
the same time fixing the aforementioned issues.

The new API allows exposing the device serial number and versions
of the components of the card - both hardware, firmware (running
and flashed).  Driver authors can choose descriptive identifiers
for the version fields.  A few version identifiers which seemed
relevant for most devices have been added to the global devlink
header.

Example:
$ devlink dev info pci/0000:05:00.0
pci/0000:05:00.0:
  driver nfp
  serial_number 16240145
  versions:
    fixed:
      board.id AMDA0099-0001
      board.rev 07
      board.vendor SMA
      board.model carbon
    running:
      fw.mgmt: 010156.010156.010156
      fw.cpld: 0x44
      fw.app: sriov-2.1.16
    stored:
      fw.mgmt: 010158.010158.010158
      fw.cpld: 0x44
      fw.app: sriov-2.1.20

Last patch also includes a compat code for ethtool.  If driver
reports no fw_version via the traditional ethtool API, ethtool
can call into devlink and try to cram as many versions as possible
into the 31 characters.

v4:
 - use IS_REACHABLE instead of IS_ENABLED in last patch.

v3 (Jiri):
 - rename various functions and attributes;
 - break out the version helpers per-type;
 - make the compat code parse a dump instead of special casing
   in each helper;
 - move generic version defines to a separate patch.

v2:
 - rebase.

this non-RFC, v3 some would say:
 - add three more versions in the NFP patches;
 - add last patch (ethool compat) - Andrew & Michal.

RFCv2:
 - use one driver op;
 - allow longer serial number;
 - wrap the skb into an opaque request struct;
 - add some common identifier into the devlink header.
====================

Signed-off-by: David S. Miller <[email protected]>

1 files changed, 232 insertions, 0 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index e6f170caf449..eb839d74bcc0 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3714,6 +3714,167 @@ out:
 	return 0;
 }
 
+struct devlink_info_req {
+	struct sk_buff *msg;
+};
+
+int devlink_info_driver_name_put(struct devlink_info_req *req, const char *name)
+{
+	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_DRIVER_NAME, name);
+}
+EXPORT_SYMBOL_GPL(devlink_info_driver_name_put);
+
+int devlink_info_serial_number_put(struct devlink_info_req *req, const char *sn)
+{
+	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_SERIAL_NUMBER, sn);
+}
+EXPORT_SYMBOL_GPL(devlink_info_serial_number_put);
+
+static int devlink_info_version_put(struct devlink_info_req *req, int attr,
+				    const char *version_name,
+				    const char *version_value)
+{
+	struct nlattr *nest;
+	int err;
+
+	nest = nla_nest_start(req->msg, attr);
+	if (!nest)
+		return -EMSGSIZE;
+
+	err = nla_put_string(req->msg, DEVLINK_ATTR_INFO_VERSION_NAME,
+			     version_name);
+	if (err)
+		goto nla_put_failure;
+
+	err = nla_put_string(req->msg, DEVLINK_ATTR_INFO_VERSION_VALUE,
+			     version_value);
+	if (err)
+		goto nla_put_failure;
+
+	nla_nest_end(req->msg, nest);
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(req->msg, nest);
+	return err;
+}
+
+int devlink_info_version_fixed_put(struct devlink_info_req *req,
+				   const char *version_name,
+				   const char *version_value)
+{
+	return devlink_info_version_put(req, DEVLINK_ATTR_INFO_VERSION_FIXED,
+					version_name, version_value);
+}
+EXPORT_SYMBOL_GPL(devlink_info_version_fixed_put);
+
+int devlink_info_version_stored_put(struct devlink_info_req *req,
+				    const char *version_name,
+				    const char *version_value)
+{
+	return devlink_info_version_put(req, DEVLINK_ATTR_INFO_VERSION_STORED,
+					version_name, version_value);
+}
+EXPORT_SYMBOL_GPL(devlink_info_version_stored_put);
+
+int devlink_info_version_running_put(struct devlink_info_req *req,
+				     const char *version_name,
+				     const char *version_value)
+{
+	return devlink_info_version_put(req, DEVLINK_ATTR_INFO_VERSION_RUNNING,
+					version_name, version_value);
+}
+EXPORT_SYMBOL_GPL(devlink_info_version_running_put);
+
+static int
+devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
+		     enum devlink_command cmd, u32 portid,
+		     u32 seq, int flags, struct netlink_ext_ack *extack)
+{
+	struct devlink_info_req req;
+	void *hdr;
+	int err;
+
+	hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	err = -EMSGSIZE;
+	if (devlink_nl_put_handle(msg, devlink))
+		goto err_cancel_msg;
+
+	req.msg = msg;
+	err = devlink->ops->info_get(devlink, &req, extack);
+	if (err)
+		goto err_cancel_msg;
+
+	genlmsg_end(msg, hdr);
+	return 0;
+
+err_cancel_msg:
+	genlmsg_cancel(msg, hdr);
+	return err;
+}
+
+static int devlink_nl_cmd_info_get_doit(struct sk_buff *skb,
+					struct genl_info *info)
+{
+	struct devlink *devlink = info->user_ptr[0];
+	struct sk_buff *msg;
+	int err;
+
+	if (!devlink->ops || !devlink->ops->info_get)
+		return -EOPNOTSUPP;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	err = devlink_nl_info_fill(msg, devlink, DEVLINK_CMD_INFO_GET,
+				   info->snd_portid, info->snd_seq, 0,
+				   info->extack);
+	if (err) {
+		nlmsg_free(msg);
+		return err;
+	}
+
+	return genlmsg_reply(msg, info);
+}
+
+static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg,
+					  struct netlink_callback *cb)
+{
+	struct devlink *devlink;
+	int start = cb->args[0];
+	int idx = 0;
+	int err;
+
+	mutex_lock(&devlink_mutex);
+	list_for_each_entry(devlink, &devlink_list, list) {
+		if (!net_eq(devlink_net(devlink), sock_net(msg->sk)))
+			continue;
+		if (idx < start) {
+			idx++;
+			continue;
+		}
+
+		mutex_lock(&devlink->lock);
+		err = devlink_nl_info_fill(msg, devlink, DEVLINK_CMD_INFO_GET,
+					   NETLINK_CB(cb->skb).portid,
+					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					   cb->extack);
+		mutex_unlock(&devlink->lock);
+		if (err)
+			break;
+		idx++;
+	}
+	mutex_unlock(&devlink_mutex);
+
+	cb->args[0] = idx;
+	return msg->len;
+}
+
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING },
@@ -3974,6 +4135,14 @@ static const struct genl_ops devlink_nl_ops[] = {
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
 	},
+	{
+		.cmd = DEVLINK_CMD_INFO_GET,
+		.doit = devlink_nl_cmd_info_get_doit,
+		.dumpit = devlink_nl_cmd_info_get_dumpit,
+		.policy = devlink_nl_policy,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+		/* can be retrieved by unprivileged users */
+	},
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {
@@ -5109,6 +5278,69 @@ unlock:
 }
 EXPORT_SYMBOL_GPL(devlink_region_snapshot_create);
 
+static void __devlink_compat_running_version(struct devlink *devlink,
+					     char *buf, size_t len)
+{
+	const struct nlattr *nlattr;
+	struct devlink_info_req req;
+	struct sk_buff *msg;
+	int rem, err;
+
+	if (!devlink->ops->info_get)
+		return;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return;
+
+	req.msg = msg;
+	err = devlink->ops->info_get(devlink, &req, NULL);
+	if (err)
+		goto free_msg;
+
+	nla_for_each_attr(nlattr, (void *)msg->data, msg->len, rem) {
+		const struct nlattr *kv;
+		int rem_kv;
+
+		if (nla_type(nlattr) != DEVLINK_ATTR_INFO_VERSION_RUNNING)
+			continue;
+
+		nla_for_each_nested(kv, nlattr, rem_kv) {
+			if (nla_type(kv) != DEVLINK_ATTR_INFO_VERSION_VALUE)
+				continue;
+
+			strlcat(buf, nla_data(kv), len);
+			strlcat(buf, " ", len);
+		}
+	}
+free_msg:
+	nlmsg_free(msg);
+}
+
+void devlink_compat_running_version(struct net_device *dev,
+				    char *buf, size_t len)
+{
+	struct devlink_port *devlink_port;
+	struct devlink *devlink;
+
+	mutex_lock(&devlink_mutex);
+	list_for_each_entry(devlink, &devlink_list, list) {
+		mutex_lock(&devlink->lock);
+		list_for_each_entry(devlink_port, &devlink->port_list, list) {
+			if (devlink_port->type == DEVLINK_PORT_TYPE_ETH ||
+			    devlink_port->type_dev == dev) {
+				__devlink_compat_running_version(devlink,
+								 buf, len);
+				mutex_unlock(&devlink->lock);
+				goto out;
+			}
+		}
+		mutex_unlock(&devlink->lock);
+	}
+out:
+	mutex_unlock(&devlink_mutex);
+}
+
 static int __init devlink_module_init(void)
 {
 	return genl_register_family(&devlink_nl_family);