Merge branch 'mlxsw-refactor-reference-counting-code'

Petr Machata says:

====================
mlxsw: Refactor reference counting code

Amit Cohen writes:

This set converts all reference counters defined as 'unsigned int' to
refcount_t type. The reference counting of LAGs can be simplified, so first
refactor the related code and then change the type of the reference
counter.

Patch set overview:
Patches #1-#4 are preparations for LAG refactor
Patch #5 refactors LAG code and change the type of reference counter
Patch #6 converts the remaining reference counters in mlxsw driver
====================

Link: https://lore.kernel.org/r/cover.1706293430.git.petrm@nvidia.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c

@@ -95,7 +95,7 @@ struct mlxsw_afa_set {
 		      */
 	   has_trap:1,
 	   has_police:1;
-	unsigned int ref_count;
+	refcount_t ref_count;
 	struct mlxsw_afa_set *next; /* Pointer to the next set. */
 	struct mlxsw_afa_set *prev; /* Pointer to the previous set,
 				     * note that set may have multiple
@@ -120,7 +120,7 @@ struct mlxsw_afa_fwd_entry {
 	struct rhash_head ht_node;
 	struct mlxsw_afa_fwd_entry_ht_key ht_key;
 	u32 kvdl_index;
-	unsigned int ref_count;
+	refcount_t ref_count;
 };
 
 static const struct rhashtable_params mlxsw_afa_fwd_entry_ht_params = {
@@ -282,7 +282,7 @@ static struct mlxsw_afa_set *mlxsw_afa_set_create(bool is_first)
 	/* Need to initialize the set to pass by default */
 	mlxsw_afa_set_goto_set(set, MLXSW_AFA_SET_GOTO_BINDING_CMD_TERM, 0);
 	set->ht_key.is_first = is_first;
-	set->ref_count = 1;
+	refcount_set(&set->ref_count, 1);
 	return set;
 }
 
@@ -330,7 +330,7 @@ static void mlxsw_afa_set_unshare(struct mlxsw_afa *mlxsw_afa,
 static void mlxsw_afa_set_put(struct mlxsw_afa *mlxsw_afa,
 			      struct mlxsw_afa_set *set)
 {
-	if (--set->ref_count)
+	if (!refcount_dec_and_test(&set->ref_count))
 		return;
 	if (set->shared)
 		mlxsw_afa_set_unshare(mlxsw_afa, set);
@@ -350,7 +350,7 @@ static struct mlxsw_afa_set *mlxsw_afa_set_get(struct mlxsw_afa *mlxsw_afa,
 	set = rhashtable_lookup_fast(&mlxsw_afa->set_ht, &orig_set->ht_key,
 				     mlxsw_afa_set_ht_params);
 	if (set) {
-		set->ref_count++;
+		refcount_inc(&set->ref_count);
 		mlxsw_afa_set_put(mlxsw_afa, orig_set);
 	} else {
 		set = orig_set;
@@ -564,7 +564,7 @@ mlxsw_afa_fwd_entry_create(struct mlxsw_afa *mlxsw_afa, u16 local_port)
 	if (!fwd_entry)
 		return ERR_PTR(-ENOMEM);
 	fwd_entry->ht_key.local_port = local_port;
-	fwd_entry->ref_count = 1;
+	refcount_set(&fwd_entry->ref_count, 1);
 
 	err = rhashtable_insert_fast(&mlxsw_afa->fwd_entry_ht,
 				     &fwd_entry->ht_node,
@@ -607,7 +607,7 @@ mlxsw_afa_fwd_entry_get(struct mlxsw_afa *mlxsw_afa, u16 local_port)
 	fwd_entry = rhashtable_lookup_fast(&mlxsw_afa->fwd_entry_ht, &ht_key,
 					   mlxsw_afa_fwd_entry_ht_params);
 	if (fwd_entry) {
-		fwd_entry->ref_count++;
+		refcount_inc(&fwd_entry->ref_count);
 		return fwd_entry;
 	}
 	return mlxsw_afa_fwd_entry_create(mlxsw_afa, local_port);
@@ -616,7 +616,7 @@ mlxsw_afa_fwd_entry_get(struct mlxsw_afa *mlxsw_afa, u16 local_port)
 static void mlxsw_afa_fwd_entry_put(struct mlxsw_afa *mlxsw_afa,
 				    struct mlxsw_afa_fwd_entry *fwd_entry)
 {
-	if (--fwd_entry->ref_count)
+	if (!refcount_dec_and_test(&fwd_entry->ref_count))
 		return;
 	mlxsw_afa_fwd_entry_destroy(mlxsw_afa, fwd_entry);
 }

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c

@@ -5,6 +5,7 @@
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/errno.h>
+#include <linux/refcount.h>
 
 #include "item.h"
 #include "core_acl_flex_keys.h"
@@ -107,7 +108,7 @@ EXPORT_SYMBOL(mlxsw_afk_destroy);
 
 struct mlxsw_afk_key_info {
 	struct list_head list;
-	unsigned int ref_count;
+	refcount_t ref_count;
 	unsigned int blocks_count;
 	int element_to_block[MLXSW_AFK_ELEMENT_MAX]; /* index is element, value
 						      * is index inside "blocks"
@@ -334,7 +335,7 @@ mlxsw_afk_key_info_create(struct mlxsw_afk *mlxsw_afk,
 	if (err)
 		goto err_picker;
 	list_add(&key_info->list, &mlxsw_afk->key_info_list);
-	key_info->ref_count = 1;
+	refcount_set(&key_info->ref_count, 1);
 	return key_info;
 
 err_picker:
@@ -356,7 +357,7 @@ mlxsw_afk_key_info_get(struct mlxsw_afk *mlxsw_afk,
 
 	key_info = mlxsw_afk_key_info_find(mlxsw_afk, elusage);
 	if (key_info) {
-		key_info->ref_count++;
+		refcount_inc(&key_info->ref_count);
 		return key_info;
 	}
 	return mlxsw_afk_key_info_create(mlxsw_afk, elusage);
@@ -365,7 +366,7 @@ EXPORT_SYMBOL(mlxsw_afk_key_info_get);
 
 void mlxsw_afk_key_info_put(struct mlxsw_afk_key_info *key_info)
 {
-	if (--key_info->ref_count)
+	if (!refcount_dec_and_test(&key_info->ref_count))
 		return;
 	mlxsw_afk_key_info_destroy(key_info);
 }

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2695,23 +2695,18 @@ static void mlxsw_sp_traps_fini(struct mlxsw_sp *mlxsw_sp)
 static int mlxsw_sp_lag_pgt_init(struct mlxsw_sp *mlxsw_sp)
 {
 	char sgcr_pl[MLXSW_REG_SGCR_LEN];
-	u16 max_lag;
 	int err;
 
 	if (mlxsw_core_lag_mode(mlxsw_sp->core) !=
 	    MLXSW_CMD_MBOX_CONFIG_PROFILE_LAG_MODE_SW)
 		return 0;
 
-	err = mlxsw_core_max_lag(mlxsw_sp->core, &max_lag);
-	if (err)
-		return err;
-
 	/* In DDD mode, which we by default use, each LAG entry is 8 PGT
 	 * entries. The LAG table address needs to be 8-aligned, but that ought
 	 * to be the case, since the LAG table is allocated first.
 	 */
 	err = mlxsw_sp_pgt_mid_alloc_range(mlxsw_sp, &mlxsw_sp->lag_pgt_base,
-					   max_lag * 8);
+					   mlxsw_sp->max_lag * 8);
 	if (err)
 		return err;
 	if (WARN_ON_ONCE(mlxsw_sp->lag_pgt_base % 8)) {
@@ -2728,33 +2723,31 @@ static int mlxsw_sp_lag_pgt_init(struct mlxsw_sp *mlxsw_sp)
 
 err_mid_alloc_range:
 	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, mlxsw_sp->lag_pgt_base,
-				    max_lag * 8);
+				    mlxsw_sp->max_lag * 8);
 	return err;
 }
 
 static void mlxsw_sp_lag_pgt_fini(struct mlxsw_sp *mlxsw_sp)
 {
-	u16 max_lag;
-	int err;
-
 	if (mlxsw_core_lag_mode(mlxsw_sp->core) !=
 	    MLXSW_CMD_MBOX_CONFIG_PROFILE_LAG_MODE_SW)
 		return;
 
-	err = mlxsw_core_max_lag(mlxsw_sp->core, &max_lag);
-	if (err)
-		return;
-
 	mlxsw_sp_pgt_mid_free_range(mlxsw_sp, mlxsw_sp->lag_pgt_base,
-				    max_lag * 8);
+				    mlxsw_sp->max_lag * 8);
 }
 
 #define MLXSW_SP_LAG_SEED_INIT 0xcafecafe
 
+struct mlxsw_sp_lag {
+	struct net_device *dev;
+	refcount_t ref_count;
+	u16 lag_id;
+};
+
 static int mlxsw_sp_lag_init(struct mlxsw_sp *mlxsw_sp)
 {
 	char slcr_pl[MLXSW_REG_SLCR_LEN];
-	u16 max_lag;
 	u32 seed;
 	int err;
 
@@ -2773,7 +2766,7 @@ static int mlxsw_sp_lag_init(struct mlxsw_sp *mlxsw_sp)
 	if (err)
 		return err;
 
-	err = mlxsw_core_max_lag(mlxsw_sp->core, &max_lag);
+	err = mlxsw_core_max_lag(mlxsw_sp->core, &mlxsw_sp->max_lag);
 	if (err)
 		return err;
 
@@ -2784,7 +2777,7 @@ static int mlxsw_sp_lag_init(struct mlxsw_sp *mlxsw_sp)
 	if (err)
 		return err;
 
-	mlxsw_sp->lags = kcalloc(max_lag, sizeof(struct mlxsw_sp_upper),
+	mlxsw_sp->lags = kcalloc(mlxsw_sp->max_lag, sizeof(struct mlxsw_sp_lag),
 				 GFP_KERNEL);
 	if (!mlxsw_sp->lags) {
 		err = -ENOMEM;
@@ -4269,19 +4262,48 @@ mlxsw_sp_port_lag_uppers_cleanup(struct mlxsw_sp_port *mlxsw_sp_port,
 	}
 }
 
-static int mlxsw_sp_lag_create(struct mlxsw_sp *mlxsw_sp, u16 lag_id)
+static struct mlxsw_sp_lag *
+mlxsw_sp_lag_create(struct mlxsw_sp *mlxsw_sp, struct net_device *lag_dev,
+		    struct netlink_ext_ack *extack)
 {
 	char sldr_pl[MLXSW_REG_SLDR_LEN];
+	struct mlxsw_sp_lag *lag;
+	u16 lag_id;
+	int i, err;
 
+	for (i = 0; i < mlxsw_sp->max_lag; i++) {
+		if (!mlxsw_sp->lags[i].dev)
+			break;
+	}
+
+	if (i == mlxsw_sp->max_lag) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Exceeded number of supported LAG devices");
+		return ERR_PTR(-EBUSY);
+	}
+
+	lag_id = i;
 	mlxsw_reg_sldr_lag_create_pack(sldr_pl, lag_id);
-	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sldr), sldr_pl);
+	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sldr), sldr_pl);
+	if (err)
+		return ERR_PTR(err);
+
+	lag = &mlxsw_sp->lags[lag_id];
+	lag->lag_id = lag_id;
+	lag->dev = lag_dev;
+	refcount_set(&lag->ref_count, 1);
+
+	return lag;
 }
 
-static int mlxsw_sp_lag_destroy(struct mlxsw_sp *mlxsw_sp, u16 lag_id)
+static int
+mlxsw_sp_lag_destroy(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_lag *lag)
 {
 	char sldr_pl[MLXSW_REG_SLDR_LEN];
 
-	mlxsw_reg_sldr_lag_destroy_pack(sldr_pl, lag_id);
+	lag->dev = NULL;
+
+	mlxsw_reg_sldr_lag_destroy_pack(sldr_pl, lag->lag_id);
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sldr), sldr_pl);
 }
 
@@ -4329,34 +4351,44 @@ static int mlxsw_sp_lag_col_port_disable(struct mlxsw_sp_port *mlxsw_sp_port,
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(slcor), slcor_pl);
 }
 
-static int mlxsw_sp_lag_index_get(struct mlxsw_sp *mlxsw_sp,
-				  struct net_device *lag_dev,
-				  u16 *p_lag_id)
+static struct mlxsw_sp_lag *
+mlxsw_sp_lag_find(struct mlxsw_sp *mlxsw_sp, struct net_device *lag_dev)
 {
-	struct mlxsw_sp_upper *lag;
-	int free_lag_id = -1;
-	u16 max_lag;
-	int err, i;
+	int i;
 
-	err = mlxsw_core_max_lag(mlxsw_sp->core, &max_lag);
-	if (err)
-		return err;
+	for (i = 0; i < mlxsw_sp->max_lag; i++) {
+		if (!mlxsw_sp->lags[i].dev)
+			continue;
 
-	for (i = 0; i < max_lag; i++) {
-		lag = mlxsw_sp_lag_get(mlxsw_sp, i);
-		if (lag->ref_count) {
-			if (lag->dev == lag_dev) {
-				*p_lag_id = i;
-				return 0;
-			}
-		} else if (free_lag_id < 0) {
-			free_lag_id = i;
+		if (mlxsw_sp->lags[i].dev == lag_dev)
+			return &mlxsw_sp->lags[i];
 	}
+
+	return NULL;
+}
+
+static struct mlxsw_sp_lag *
+mlxsw_sp_lag_get(struct mlxsw_sp *mlxsw_sp, struct net_device *lag_dev,
+		 struct netlink_ext_ack *extack)
+{
+	struct mlxsw_sp_lag *lag;
+
+	lag = mlxsw_sp_lag_find(mlxsw_sp, lag_dev);
+	if (lag) {
+		refcount_inc(&lag->ref_count);
+		return lag;
 	}
-	if (free_lag_id < 0)
-		return -EBUSY;
-	*p_lag_id = free_lag_id;
-	return 0;
+
+	return mlxsw_sp_lag_create(mlxsw_sp, lag_dev, extack);
+}
+
+static void
+mlxsw_sp_lag_put(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_lag *lag)
+{
+	if (!refcount_dec_and_test(&lag->ref_count))
+		return;
+
+	mlxsw_sp_lag_destroy(mlxsw_sp, lag);
 }
 
 static bool
@@ -4365,12 +4397,6 @@ mlxsw_sp_master_lag_check(struct mlxsw_sp *mlxsw_sp,
 			  struct netdev_lag_upper_info *lag_upper_info,
 			  struct netlink_ext_ack *extack)
 {
-	u16 lag_id;
-
-	if (mlxsw_sp_lag_index_get(mlxsw_sp, lag_dev, &lag_id) != 0) {
-		NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported LAG devices");
-		return false;
-	}
 	if (lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH) {
 		NL_SET_ERR_MSG_MOD(extack, "LAG device using unsupported Tx type");
 		return false;
@@ -4482,22 +4508,16 @@ static int mlxsw_sp_port_lag_join(struct mlxsw_sp_port *mlxsw_sp_port,
 				  struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
-	struct mlxsw_sp_upper *lag;
+	struct mlxsw_sp_lag *lag;
 	u16 lag_id;
 	u8 port_index;
 	int err;
 
-	err = mlxsw_sp_lag_index_get(mlxsw_sp, lag_dev, &lag_id);
-	if (err)
-		return err;
-	lag = mlxsw_sp_lag_get(mlxsw_sp, lag_id);
-	if (!lag->ref_count) {
-		err = mlxsw_sp_lag_create(mlxsw_sp, lag_id);
-		if (err)
-			return err;
-		lag->dev = lag_dev;
-	}
+	lag = mlxsw_sp_lag_get(mlxsw_sp, lag_dev, extack);
+	if (IS_ERR(lag))
+		return PTR_ERR(lag);
 
+	lag_id = lag->lag_id;
 	err = mlxsw_sp_port_lag_index_get(mlxsw_sp, lag_id, &port_index);
 	if (err)
 		return err;
@@ -4515,7 +4535,6 @@ static int mlxsw_sp_port_lag_join(struct mlxsw_sp_port *mlxsw_sp_port,
 				   mlxsw_sp_port->local_port);
 	mlxsw_sp_port->lag_id = lag_id;
 	mlxsw_sp_port->lagged = 1;
-	lag->ref_count++;
 
 	err = mlxsw_sp_fid_port_join_lag(mlxsw_sp_port);
 	if (err)
@@ -4542,7 +4561,6 @@ static int mlxsw_sp_port_lag_join(struct mlxsw_sp_port *mlxsw_sp_port,
 err_router_join:
 	mlxsw_sp_fid_port_leave_lag(mlxsw_sp_port);
 err_fid_port_join_lag:
-	lag->ref_count--;
 	mlxsw_sp_port->lagged = 0;
 	mlxsw_core_lag_mapping_clear(mlxsw_sp->core, lag_id,
 				     mlxsw_sp_port->local_port);
@@ -4550,8 +4568,7 @@ static int mlxsw_sp_port_lag_join(struct mlxsw_sp_port *mlxsw_sp_port,
 err_col_port_add:
 	mlxsw_sp_lag_uppers_bridge_leave(mlxsw_sp_port, lag_dev);
 err_lag_uppers_bridge_join:
-	if (!lag->ref_count)
-		mlxsw_sp_lag_destroy(mlxsw_sp, lag_id);
+	mlxsw_sp_lag_put(mlxsw_sp, lag);
 	return err;
 }
 
@@ -4560,12 +4577,11 @@ static void mlxsw_sp_port_lag_leave(struct mlxsw_sp_port *mlxsw_sp_port,
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	u16 lag_id = mlxsw_sp_port->lag_id;
-	struct mlxsw_sp_upper *lag;
+	struct mlxsw_sp_lag *lag;
 
 	if (!mlxsw_sp_port->lagged)
 		return;
-	lag = mlxsw_sp_lag_get(mlxsw_sp, lag_id);
-	WARN_ON(lag->ref_count == 0);
+	lag = &mlxsw_sp->lags[lag_id];
 
 	mlxsw_sp_lag_col_port_remove(mlxsw_sp_port, lag_id);
 
@@ -4579,13 +4595,11 @@ static void mlxsw_sp_port_lag_leave(struct mlxsw_sp_port *mlxsw_sp_port,
 
 	mlxsw_sp_fid_port_leave_lag(mlxsw_sp_port);
 
-	if (lag->ref_count == 1)
-		mlxsw_sp_lag_destroy(mlxsw_sp, lag_id);
+	mlxsw_sp_lag_put(mlxsw_sp, lag);
 
 	mlxsw_core_lag_mapping_clear(mlxsw_sp->core, lag_id,
 				     mlxsw_sp_port->local_port);
 	mlxsw_sp_port->lagged = 0;
-	lag->ref_count--;
 
 	/* Make sure untagged frames are allowed to ingress */
 	mlxsw_sp_port_pvid_set(mlxsw_sp_port, MLXSW_SP_DEFAULT_VID,

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -78,11 +78,6 @@ struct mlxsw_sp_span_entry;
 enum mlxsw_sp_l3proto;
 union mlxsw_sp_l3addr;
 
-struct mlxsw_sp_upper {
-	struct net_device *dev;
-	unsigned int ref_count;
-};
-
 enum mlxsw_sp_rif_type {
 	MLXSW_SP_RIF_TYPE_SUBPORT,
 	MLXSW_SP_RIF_TYPE_VLAN,
@@ -136,6 +131,7 @@ struct mlxsw_sp_span_ops;
 struct mlxsw_sp_qdisc_state;
 struct mlxsw_sp_mall_entry;
 struct mlxsw_sp_pgt;
+struct mlxsw_sp_lag;
 
 struct mlxsw_sp_port_mapping {
 	u8 module;
@@ -164,7 +160,8 @@ struct mlxsw_sp {
 	const struct mlxsw_bus_info *bus_info;
 	unsigned char base_mac[ETH_ALEN];
 	const unsigned char *mac_mask;
-	struct mlxsw_sp_upper *lags;
+	struct mlxsw_sp_lag *lags;
+	u16 max_lag;
 	struct mlxsw_sp_port_mapping *port_mapping;
 	struct mlxsw_sp_port_mapping_events port_mapping_events;
 	struct rhashtable sample_trigger_ht;
@@ -257,12 +254,6 @@ struct mlxsw_sp_fid_core_ops {
 	void (*fini)(struct mlxsw_sp *mlxsw_sp);
 };
 
-static inline struct mlxsw_sp_upper *
-mlxsw_sp_lag_get(struct mlxsw_sp *mlxsw_sp, u16 lag_id)
-{
-	return &mlxsw_sp->lags[lag_id];
-}
-
 struct mlxsw_sp_port_pcpu_stats {
 	u64			rx_packets;
 	u64			rx_bytes;

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c

@@ -9,6 +9,7 @@
 #include <linux/rhashtable.h>
 #include <linux/netdevice.h>
 #include <linux/mutex.h>
+#include <linux/refcount.h>
 #include <net/net_namespace.h>
 #include <net/tc_act/tc_vlan.h>
 
@@ -55,7 +56,7 @@ struct mlxsw_sp_acl_ruleset {
 	struct rhash_head ht_node; /* Member of acl HT */
 	struct mlxsw_sp_acl_ruleset_ht_key ht_key;
 	struct rhashtable rule_ht;
-	unsigned int ref_count;
+	refcount_t ref_count;
 	unsigned int min_prio;
 	unsigned int max_prio;
 	unsigned long priv[];
@@ -99,7 +100,7 @@ static bool
 mlxsw_sp_acl_ruleset_is_singular(const struct mlxsw_sp_acl_ruleset *ruleset)
 {
 	/* We hold a reference on ruleset ourselves */
-	return ruleset->ref_count == 2;
+	return refcount_read(&ruleset->ref_count) == 2;
 }
 
 int mlxsw_sp_acl_ruleset_bind(struct mlxsw_sp *mlxsw_sp,
@@ -176,7 +177,7 @@ mlxsw_sp_acl_ruleset_create(struct mlxsw_sp *mlxsw_sp,
 	ruleset = kzalloc(alloc_size, GFP_KERNEL);
 	if (!ruleset)
 		return ERR_PTR(-ENOMEM);
-	ruleset->ref_count = 1;
+	refcount_set(&ruleset->ref_count, 1);
 	ruleset->ht_key.block = block;
 	ruleset->ht_key.chain_index = chain_index;
 	ruleset->ht_key.ops = ops;
@@ -222,13 +223,13 @@ static void mlxsw_sp_acl_ruleset_destroy(struct mlxsw_sp *mlxsw_sp,
 
 static void mlxsw_sp_acl_ruleset_ref_inc(struct mlxsw_sp_acl_ruleset *ruleset)
 {
-	ruleset->ref_count++;
+	refcount_inc(&ruleset->ref_count);
 }
 
 static void mlxsw_sp_acl_ruleset_ref_dec(struct mlxsw_sp *mlxsw_sp,
 					 struct mlxsw_sp_acl_ruleset *ruleset)
 {
-	if (--ruleset->ref_count)
+	if (!refcount_dec_and_test(&ruleset->ref_count))
 		return;
 	mlxsw_sp_acl_ruleset_destroy(mlxsw_sp, ruleset);
 }

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c

@@ -9,6 +9,7 @@
 #include <linux/rhashtable.h>
 #include <linux/netdevice.h>
 #include <linux/mutex.h>
+#include <linux/refcount.h>
 #include <net/devlink.h>
 #include <trace/events/mlxsw.h>
 
@@ -155,7 +156,7 @@ struct mlxsw_sp_acl_tcam_vregion {
 		struct mlxsw_sp_acl_tcam_rehash_ctx ctx;
 	} rehash;
 	struct mlxsw_sp *mlxsw_sp;
-	unsigned int ref_count;
+	refcount_t ref_count;
 };
 
 struct mlxsw_sp_acl_tcam_vchunk;
@@ -176,7 +177,7 @@ struct mlxsw_sp_acl_tcam_vchunk {
 	unsigned int priority; /* Priority within the vregion and group */
 	struct mlxsw_sp_acl_tcam_vgroup *vgroup;
 	struct mlxsw_sp_acl_tcam_vregion *vregion;
-	unsigned int ref_count;
+	refcount_t ref_count;
 };
 
 struct mlxsw_sp_acl_tcam_entry {
@@ -769,7 +770,7 @@ mlxsw_sp_acl_tcam_vregion_create(struct mlxsw_sp *mlxsw_sp,
 	vregion->tcam = tcam;
 	vregion->mlxsw_sp = mlxsw_sp;
 	vregion->vgroup = vgroup;
-	vregion->ref_count = 1;
+	refcount_set(&vregion->ref_count, 1);
 
 	vregion->key_info = mlxsw_afk_key_info_get(afk, elusage);
 	if (IS_ERR(vregion->key_info)) {
@@ -856,7 +857,7 @@ mlxsw_sp_acl_tcam_vregion_get(struct mlxsw_sp *mlxsw_sp,
 			 */
 			return ERR_PTR(-EOPNOTSUPP);
 		}
-		vregion->ref_count++;
+		refcount_inc(&vregion->ref_count);
 		return vregion;
 	}
 
@@ -871,7 +872,7 @@ static void
 mlxsw_sp_acl_tcam_vregion_put(struct mlxsw_sp *mlxsw_sp,
 			      struct mlxsw_sp_acl_tcam_vregion *vregion)
 {
-	if (--vregion->ref_count)
+	if (!refcount_dec_and_test(&vregion->ref_count))
 		return;
 	mlxsw_sp_acl_tcam_vregion_destroy(mlxsw_sp, vregion);
 }
@@ -924,7 +925,7 @@ mlxsw_sp_acl_tcam_vchunk_create(struct mlxsw_sp *mlxsw_sp,
 	INIT_LIST_HEAD(&vchunk->ventry_list);
 	vchunk->priority = priority;
 	vchunk->vgroup = vgroup;
-	vchunk->ref_count = 1;
+	refcount_set(&vchunk->ref_count, 1);
 
 	vregion = mlxsw_sp_acl_tcam_vregion_get(mlxsw_sp, vgroup,
 						priority, elusage);
@@ -1008,7 +1009,7 @@ mlxsw_sp_acl_tcam_vchunk_get(struct mlxsw_sp *mlxsw_sp,
 		if (WARN_ON(!mlxsw_afk_key_info_subset(vchunk->vregion->key_info,
 						       elusage)))
 			return ERR_PTR(-EINVAL);
-		vchunk->ref_count++;
+		refcount_inc(&vchunk->ref_count);
 		return vchunk;
 	}
 	return mlxsw_sp_acl_tcam_vchunk_create(mlxsw_sp, vgroup,
@@ -1019,7 +1020,7 @@ static void
 mlxsw_sp_acl_tcam_vchunk_put(struct mlxsw_sp *mlxsw_sp,
 			     struct mlxsw_sp_acl_tcam_vchunk *vchunk)
 {
-	if (--vchunk->ref_count)
+	if (!refcount_dec_and_test(&vchunk->ref_count))
 		return;
 	mlxsw_sp_acl_tcam_vchunk_destroy(mlxsw_sp, vchunk);
 }

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -501,7 +501,7 @@ struct mlxsw_sp_rt6 {
 
 struct mlxsw_sp_lpm_tree {
 	u8 id; /* tree ID */
-	unsigned int ref_count;
+	refcount_t ref_count;
 	enum mlxsw_sp_l3proto proto;
 	unsigned long prefix_ref_count[MLXSW_SP_PREFIX_COUNT];
 	struct mlxsw_sp_prefix_usage prefix_usage;
@@ -578,7 +578,7 @@ mlxsw_sp_lpm_tree_find_unused(struct mlxsw_sp *mlxsw_sp)
 
 	for (i = 0; i < mlxsw_sp->router->lpm.tree_count; i++) {
 		lpm_tree = &mlxsw_sp->router->lpm.trees[i];
-		if (lpm_tree->ref_count == 0)
+		if (refcount_read(&lpm_tree->ref_count) == 0)
 			return lpm_tree;
 	}
 	return NULL;
@@ -654,7 +654,7 @@ mlxsw_sp_lpm_tree_create(struct mlxsw_sp *mlxsw_sp,
 	       sizeof(lpm_tree->prefix_usage));
 	memset(&lpm_tree->prefix_ref_count, 0,
 	       sizeof(lpm_tree->prefix_ref_count));
-	lpm_tree->ref_count = 1;
+	refcount_set(&lpm_tree->ref_count, 1);
 	return lpm_tree;
 
 err_left_struct_set:
@@ -678,7 +678,7 @@ mlxsw_sp_lpm_tree_get(struct mlxsw_sp *mlxsw_sp,
 
 	for (i = 0; i < mlxsw_sp->router->lpm.tree_count; i++) {
 		lpm_tree = &mlxsw_sp->router->lpm.trees[i];
-		if (lpm_tree->ref_count != 0 &&
+		if (refcount_read(&lpm_tree->ref_count) &&
 		    lpm_tree->proto == proto &&
 		    mlxsw_sp_prefix_usage_eq(&lpm_tree->prefix_usage,
 					     prefix_usage)) {
@@ -691,13 +691,14 @@ mlxsw_sp_lpm_tree_get(struct mlxsw_sp *mlxsw_sp,
 
 static void mlxsw_sp_lpm_tree_hold(struct mlxsw_sp_lpm_tree *lpm_tree)
 {
-	lpm_tree->ref_count++;
+	refcount_inc(&lpm_tree->ref_count);
 }
 
 static void mlxsw_sp_lpm_tree_put(struct mlxsw_sp *mlxsw_sp,
 				  struct mlxsw_sp_lpm_tree *lpm_tree)
 {
-	if (--lpm_tree->ref_count == 0)
+	if (!refcount_dec_and_test(&lpm_tree->ref_count))
+		return;
 	mlxsw_sp_lpm_tree_destroy(mlxsw_sp, lpm_tree);
 }
 

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -61,7 +61,7 @@ struct mlxsw_sp_bridge_port {
 	struct mlxsw_sp_bridge_device *bridge_device;
 	struct list_head list;
 	struct list_head vlans_list;
-	unsigned int ref_count;
+	refcount_t ref_count;
 	u8 stp_state;
 	unsigned long flags;
 	bool mrouter;
@@ -495,7 +495,7 @@ mlxsw_sp_bridge_port_create(struct mlxsw_sp_bridge_device *bridge_device,
 			     BR_MCAST_FLOOD;
 	INIT_LIST_HEAD(&bridge_port->vlans_list);
 	list_add(&bridge_port->list, &bridge_device->ports_list);
-	bridge_port->ref_count = 1;
+	refcount_set(&bridge_port->ref_count, 1);
 
 	err = switchdev_bridge_port_offload(brport_dev, mlxsw_sp_port->dev,
 					    NULL, NULL, NULL, false, extack);
@@ -531,7 +531,7 @@ mlxsw_sp_bridge_port_get(struct mlxsw_sp_bridge *bridge,
 
 	bridge_port = mlxsw_sp_bridge_port_find(bridge, brport_dev);
 	if (bridge_port) {
-		bridge_port->ref_count++;
+		refcount_inc(&bridge_port->ref_count);
 		return bridge_port;
 	}
 
@@ -558,7 +558,7 @@ static void mlxsw_sp_bridge_port_put(struct mlxsw_sp_bridge *bridge,
 {
 	struct mlxsw_sp_bridge_device *bridge_device;
 
-	if (--bridge_port->ref_count != 0)
+	if (!refcount_dec_and_test(&bridge_port->ref_count))
 		return;
 	bridge_device = bridge_port->bridge_device;
 	mlxsw_sp_bridge_port_destroy(bridge_port);