mlxsw: spectrum_acl: Introduce mutex to guard Bloom Filter updates

Bloom filter is shared within multiple regions. For updates, it needs to
be guarded by a separate mutex. Do that in order to not rely on RTNL
mutex.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
index 9545b57..3a2de13 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_bloom_filter.c
@@ -5,11 +5,13 @@
 #include <linux/gfp.h>
 #include <linux/kernel.h>
 #include <linux/refcount.h>
+#include <linux/mutex.h>
 
 #include "spectrum.h"
 #include "spectrum_acl_tcam.h"
 
 struct mlxsw_sp_acl_bf {
+       struct mutex lock; /* Protects Bloom Filter updates. */
        unsigned int bank_size;
        refcount_t refcnt[0];
 };
@@ -172,26 +174,36 @@ mlxsw_sp_acl_bf_entry_add(struct mlxsw_sp *mlxsw_sp,
        u16 bf_index;
        int err;
 
+       mutex_lock(&bf->lock);
+
        bf_index = mlxsw_sp_acl_bf_index_get(bf, aregion, aentry);
        rule_index = mlxsw_sp_acl_bf_rule_count_index_get(bf, erp_bank,
                                                          bf_index);
 
-       if (refcount_inc_not_zero(&bf->refcnt[rule_index]))
-               return 0;
+       if (refcount_inc_not_zero(&bf->refcnt[rule_index])) {
+               err = 0;
+               goto unlock;
+       }
 
        peabfe_pl = kmalloc(MLXSW_REG_PEABFE_LEN, GFP_KERNEL);
-       if (!peabfe_pl)
-               return -ENOMEM;
+       if (!peabfe_pl) {
+               err = -ENOMEM;
+               goto unlock;
+       }
 
        mlxsw_reg_peabfe_pack(peabfe_pl);
        mlxsw_reg_peabfe_rec_pack(peabfe_pl, 0, 1, erp_bank, bf_index);
        err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(peabfe), peabfe_pl);
        kfree(peabfe_pl);
        if (err)
-               return err;
+               goto unlock;
 
        refcount_set(&bf->refcnt[rule_index], 1);
-       return 0;
+       err = 0;
+
+unlock:
+       mutex_unlock(&bf->lock);
+       return err;
 }
 
 void
@@ -205,6 +217,8 @@ mlxsw_sp_acl_bf_entry_del(struct mlxsw_sp *mlxsw_sp,
        char *peabfe_pl;
        u16 bf_index;
 
+       mutex_lock(&bf->lock);
+
        bf_index = mlxsw_sp_acl_bf_index_get(bf, aregion, aentry);
        rule_index = mlxsw_sp_acl_bf_rule_count_index_get(bf, erp_bank,
                                                          bf_index);
@@ -212,13 +226,16 @@ mlxsw_sp_acl_bf_entry_del(struct mlxsw_sp *mlxsw_sp,
        if (refcount_dec_and_test(&bf->refcnt[rule_index])) {
                peabfe_pl = kmalloc(MLXSW_REG_PEABFE_LEN, GFP_KERNEL);
                if (!peabfe_pl)
-                       return;
+                       goto unlock;
 
                mlxsw_reg_peabfe_pack(peabfe_pl);
                mlxsw_reg_peabfe_rec_pack(peabfe_pl, 0, 0, erp_bank, bf_index);
                mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(peabfe), peabfe_pl);
                kfree(peabfe_pl);
        }
+
+unlock:
+       mutex_unlock(&bf->lock);
 }
 
 struct mlxsw_sp_acl_bf *
@@ -240,10 +257,13 @@ mlxsw_sp_acl_bf_init(struct mlxsw_sp *mlxsw_sp, unsigned int num_erp_banks)
                return ERR_PTR(-ENOMEM);
 
        bf->bank_size = bf_bank_size;
+       mutex_init(&bf->lock);
+
        return bf;
 }
 
 void mlxsw_sp_acl_bf_fini(struct mlxsw_sp_acl_bf *bf)
 {
+       mutex_destroy(&bf->lock);
        kfree(bf);
 }