[patch net-next 03/10] devlink: Add support for reload

[Jiri Pirko <jiri@resnulli.us>]

From: Arkadi Sharshevsky <arkadis@mellanox.com>

Add support for performing driver hot reload.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/devlink.h        |  1 +
 include/uapi/linux/devlink.h |  5 ++++
 net/core/devlink.c           | 57 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index a94a155..340c2fc 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -265,6 +265,7 @@ struct devlink_resource {
 #define DEVLINK_RESOURCE_ID_PARENT_TOP 0
 
 struct devlink_ops {
+	int (*reload)(struct devlink *devlink);
 	int (*port_type_set)(struct devlink_port *devlink_port,
 			     enum devlink_port_type port_type);
 	int (*port_split)(struct devlink *devlink, unsigned int port_index,
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 382981e..bee827b 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -73,6 +73,11 @@ enum devlink_command {
 	DEVLINK_CMD_RESOURCE_SET,
 	DEVLINK_CMD_RESOURCE_DUMP,
 
+	/* Hot driver reload, makes configuration changes take place. The
+	 * devlink instance is not released during the process.
+	 */
+	DEVLINK_CMD_RELOAD,
+
 	/* 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 88d5dc0..3dedc3f 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2490,6 +2490,56 @@ static int devlink_nl_cmd_resource_dump(struct sk_buff *skb,
 	return devlink_resource_fill(info, DEVLINK_CMD_RESOURCE_DUMP, 0);
 }
 
+static int
+devlink_resources_validate(struct devlink *devlink,
+			   struct devlink_resource *resource,
+			   struct genl_info *info)
+{
+	struct list_head *resource_list;
+	int err = 0;
+
+	if (resource)
+		resource_list = &resource->resource_list;
+	else
+		resource_list = &devlink->resource_list;
+
+	list_for_each_entry(resource, resource_list, list) {
+		if (!resource->size_valid)
+			return -EINVAL;
+		err = devlink_resources_validate(devlink, resource, info);
+		if (err)
+			return err;
+	}
+	return err;
+}
+
+static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
+{
+	struct devlink *devlink = info->user_ptr[0];
+	int err;
+
+	if (!devlink->ops->reload)
+		return -EOPNOTSUPP;
+
+	err = devlink_resources_validate(devlink, NULL, info);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "resources size validation failed");
+		return err;
+	}
+
+	/* During the reload the driver performs sb/dpipe register/
+	 * unregister which requires pre release of the per instance
+	 * devlink lock. The global devlink lock is taken and protects
+	 * from disruption by user-calls.
+	 */
+	mutex_unlock(&devlink->lock);
+	err = devlink->ops->reload(devlink);
+	mutex_lock(&devlink->lock);
+
+	return err;
+}
+
 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 },
@@ -2682,6 +2732,13 @@ static const struct genl_ops devlink_nl_ops[] = {
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
 	},
+	{
+		.cmd = DEVLINK_CMD_RELOAD,
+		.doit = devlink_nl_cmd_reload,
+		.policy = devlink_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+	},
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {
-- 
2.9.5