[patch net-next RFC v2 03/11] devlink: Add support for reload

[Jiri Pirko]

From: Arkadi Sharshevsky <arka...@mellanox.com>

Add support for performing driver hot reload.

Signed-off-by: Arkadi Sharshevsky <arka...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 include/net/devlink.h        |  1 +
 include/uapi/linux/devlink.h |  5 ++++
 net/core/devlink.c           | 56 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 960e80a..a33bda4 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 1ee1c72..ea4fa25 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, used to query updated resources. 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 6ae644f..d93f176 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2468,6 +2468,55 @@ 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->resource_ops &&
+                   resource->resource_ops->size_validate) {
+                       err = resource->resource_ops->size_validate(devlink,
+                                                                   
resource->size,
+                                                                   
&resource->resource_list,
+                                                                   
info->extack);
+                       if (err)
+                               return err;
+               }
+               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)
+               return err;
+
+       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 },
@@ -2658,6 +2707,13 @@ 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