[PATCH net-next 2/9] devlink: Add callback to query for snapshot id before snapshot create

[Alex Vesker]

To restrict the driver with the snapshot ID selection a new callback
is introduced for the driver to get the snapshot ID before creating
a new snapshot. This will also allow giving the same ID for multiple
snapshots taken of different regions on the same time.

Signed-off-by: Alex Vesker <va...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 include/net/devlink.h |  8 ++++++++
 net/core/devlink.c    | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 784a33c..5697c55 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -29,6 +29,7 @@ struct devlink {
        struct list_head resource_list;
        struct devlink_dpipe_headers *dpipe_headers;
        struct list_head region_list;
+       u32 snapshot_id;
        const struct devlink_ops *ops;
        struct device *dev;
        possible_net_t _net;
@@ -427,6 +428,7 @@ struct devlink_region *devlink_region_create(struct devlink 
*devlink,
                                             u32 region_max_snapshots,
                                             u64 region_size);
 void devlink_region_destroy(struct devlink_region *region);
+u32 devlink_region_shapshot_id_get(struct devlink *devlink);
 
 #else
 
@@ -611,6 +613,12 @@ static inline bool 
devlink_dpipe_table_counter_enabled(struct devlink *devlink,
 {
 }
 
+static inline u32
+devlink_region_shapshot_id_get(struct devlink *devlink)
+{
+       return 0;
+}
+
 #endif
 
 #endif /* _NET_DEVLINK_H_ */
diff --git a/net/core/devlink.c b/net/core/devlink.c
index fd5b9f6..4822a08 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3399,6 +3399,27 @@ void devlink_region_destroy(struct devlink_region 
*region)
 }
 EXPORT_SYMBOL_GPL(devlink_region_destroy);
 
+/**
+ *     devlink_region_shapshot_id_get - get snapshot ID
+ *
+ *     This callback should be called when adding a new snapshot,
+ *     Driver should use the same id for multiple snapshots taken
+ *     on multiple regions at the same time/by the same trigger.
+ *
+ *     @devlink: devlink
+ */
+u32 devlink_region_shapshot_id_get(struct devlink *devlink)
+{
+       u32 id;
+
+       mutex_lock(&devlink->lock);
+       id = ++devlink->snapshot_id;
+       mutex_unlock(&devlink->lock);
+
+       return id;
+}
+EXPORT_SYMBOL_GPL(devlink_region_shapshot_id_get);
+
 static int __init devlink_module_init(void)
 {
        return genl_register_family(&devlink_nl_family);
-- 
1.8.3.1