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 torvalds#6 converts the remaining reference counters in mlxsw driver
====================

Link: https://lore.kernel.org/r/cover.1706293430.git.petrm@nvidia.com
Signed-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);
 }