From: Jacob Keller <jacob.e.keller@intel.com>
Date: Thu, 26 Mar 2020 11:37:09 -0700
Subject: devlink: convert snapshot destructor callback to region op
Patch-mainline: v5.7-rc1
Git-commit: a0a09f6bb2c1501e24246edf2a7d42558d263b2b
References: jsc#SLE-15171

It does not makes sense that two snapshots for a given region would use
different destructors. Simplify snapshot creation by adding
a .destructor op for regions.

This operation will replace the data_destructor for the snapshot
creation, and makes snapshot creation easier.

Noticed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx4/crdump.c |    6 ++++--
 drivers/net/netdevsim/dev.c                 |    3 ++-
 include/net/devlink.h                       |    7 +++----
 net/core/devlink.c                          |   11 +++++------
 4 files changed, 14 insertions(+), 13 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/crdump.c
+++ b/drivers/net/ethernet/mellanox/mlx4/crdump.c
@@ -43,10 +43,12 @@ static const char * const region_fw_heal
 
 static const struct devlink_region_ops region_cr_space_ops = {
 	.name = region_cr_space_str,
+	.destructor = &kvfree,
 };
 
 static const struct devlink_region_ops region_fw_health_ops = {
 	.name = region_fw_health_str,
+	.destructor = &kvfree,
 };
 
 /* Set to true in case cr enable bit was set to true before crdump */
@@ -107,7 +109,7 @@ static void mlx4_crdump_collect_crspace(
 					readl(cr_space + offset);
 
 		err = devlink_region_snapshot_create(crdump->region_crspace,
-						     crspace_data, id, &kvfree);
+						     crspace_data, id);
 		if (err) {
 			kvfree(crspace_data);
 			mlx4_warn(dev, "crdump: devlink create %s snapshot id %d err %d\n",
@@ -146,7 +148,7 @@ static void mlx4_crdump_collect_fw_healt
 					readl(health_buf_start + offset);
 
 		err = devlink_region_snapshot_create(crdump->region_fw_health,
-						     health_data, id, &kvfree);
+						     health_data, id);
 		if (err) {
 			kvfree(health_data);
 			mlx4_warn(dev, "crdump: devlink create %s snapshot id %d err %d\n",
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -55,7 +55,7 @@ static ssize_t nsim_dev_take_snapshot_wr
 
 	id = devlink_region_snapshot_id_get(priv_to_devlink(nsim_dev));
 	err = devlink_region_snapshot_create(nsim_dev->dummy_region,
-					     dummy_data, id, kfree);
+					     dummy_data, id);
 	if (err) {
 		pr_err("Failed to create region snapshot\n");
 		kfree(dummy_data);
@@ -247,6 +247,7 @@ static void nsim_devlink_param_load_driv
 
 static const struct devlink_region_ops dummy_region_ops = {
 	.name = "dummy",
+	.destructor = &kfree,
 };
 
 static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -495,14 +495,14 @@ enum devlink_param_generic_id {
 struct devlink_region;
 struct devlink_info_req;
 
-typedef void devlink_snapshot_data_dest_t(const void *data);
-
 /**
  * struct devlink_region_ops - Region operations
  * @name: region name
+ * @destructor: callback used to free snapshot memory when deleting
  */
 struct devlink_region_ops {
 	const char *name;
+	void (*destructor)(const void *data);
 };
 
 struct devlink_fmsg;
@@ -976,8 +976,7 @@ devlink_region_create(struct devlink *de
 void devlink_region_destroy(struct devlink_region *region);
 u32 devlink_region_snapshot_id_get(struct devlink *devlink);
 int devlink_region_snapshot_create(struct devlink_region *region,
-				   u8 *data, u32 snapshot_id,
-				   devlink_snapshot_data_dest_t *data_destructor);
+				   u8 *data, u32 snapshot_id);
 int devlink_info_serial_number_put(struct devlink_info_req *req,
 				   const char *sn);
 int devlink_info_driver_name_put(struct devlink_info_req *req,
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -354,7 +354,6 @@ struct devlink_region {
 struct devlink_snapshot {
 	struct list_head list;
 	struct devlink_region *region;
-	devlink_snapshot_data_dest_t *data_destructor;
 	u8 *data;
 	u32 id;
 };
@@ -3774,7 +3773,7 @@ static void devlink_region_snapshot_del(
 	devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_DEL);
 	region->cur_snapshots--;
 	list_del(&snapshot->list);
-	(*snapshot->data_destructor)(snapshot->data);
+	region->ops->destructor(snapshot->data);
 	kfree(snapshot);
 }
 
@@ -7638,6 +7637,9 @@ devlink_region_create(struct devlink *de
 	struct devlink_region *region;
 	int err = 0;
 
+	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
+		return ERR_PTR(-EINVAL);
+
 	mutex_lock(&devlink->lock);
 
 	if (devlink_region_get_by_name(devlink, ops->name)) {
@@ -7724,11 +7726,9 @@ EXPORT_SYMBOL_GPL(devlink_region_snapsho
  *	@region: devlink region of the snapshot
  *	@data: snapshot data
  *	@snapshot_id: snapshot id to be created
- *	@data_destructor: pointer to destructor function to free data
  */
 int devlink_region_snapshot_create(struct devlink_region *region,
-				   u8 *data, u32 snapshot_id,
-				   devlink_snapshot_data_dest_t *data_destructor)
+				   u8 *data, u32 snapshot_id)
 {
 	struct devlink *devlink = region->devlink;
 	struct devlink_snapshot *snapshot;
@@ -7756,7 +7756,6 @@ int devlink_region_snapshot_create(struc
 	snapshot->id = snapshot_id;
 	snapshot->region = region;
 	snapshot->data = data;
-	snapshot->data_destructor = data_destructor;
 
 	list_add_tail(&snapshot->list, &region->snapshot_list);