devlink: Add support for reload

Add support for performing driver hot reload.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 53 insertions, 0 deletions

diff --git a/include/net/devlink.h b/include/net/devlink.h
index ceb1895d119b..c698883fb0bb 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -281,6 +281,7 @@ 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 f89950443e17..555ddcaf0be2 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 89b3704fa450..4c3d85560436 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2515,6 +2515,45 @@ 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;
+        }
+        return devlink->ops->reload(devlink);
+}
+
 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 },
@@ -2709,6 +2748,14 @@ 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 |
+                                  DEVLINK_NL_FLAG_NO_LOCK,
+        },
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {