mlxsw: spectrum: Fix incorrect parsing depth after reload

[ Upstream commit 2cb8bcbaf7c7e10c5489d01766f06f27e7b728af ]

Spectrum ASICs have a configurable limit on how deep into the packet
they parse. By default, the limit is 96 bytes.

There are several cases where this parsing depth is not enough and there
is a need to increase it. For example, timestamping of PTP packets and a
FIB multipath hash policy that requires hashing on inner fields. The
driver therefore maintains a reference count that reflects the number of
consumers that require an increased parsing depth.

During reload_down() the parsing depth reference count does not
necessarily drop to zero, but the parsing depth itself is restored to
the default during reload_up() when the firmware is reset. It is
therefore possible to end up in situations where the driver thinks that
the parsing depth was increased (reference count is non-zero), when it
is not.

Fix by making sure that all the consumers that increase the parsing
depth reference count also decrease it during reload_down().
Specifically, make sure that when the routing code is de-initialized it
drops the reference count if it was increased because of a FIB multipath
hash policy that requires hashing on inner fields.

Add a warning if the reference count is not zero after the driver was
de-initialized and explicitly reset it to zero during initialization for
good measures.

Fixes: c0b97b4d40a1 ("mlxsw: spectrum: Add infrastructure for parsing configuration")
Reported-by: Maksym Yaremchuk <maksymy@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/9c35e1b3e6c1d8f319a2449d14e2b86373f3b3ba.1678727526.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 5bcf5bceff7107d0a1d714d65a6b5bf9c2b3b3ba..67ecdb9e708f90a13930970c6593445493e0ef74 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2931,6 +2931,7 @@ static int mlxsw_sp_netdevice_event(struct notifier_block *unused,
 
 static void mlxsw_sp_parsing_init(struct mlxsw_sp *mlxsw_sp)
 {
+       refcount_set(&mlxsw_sp->parsing.parsing_depth_ref, 0);
        mlxsw_sp->parsing.parsing_depth = MLXSW_SP_DEFAULT_PARSING_DEPTH;
        mlxsw_sp->parsing.vxlan_udp_dport = MLXSW_SP_DEFAULT_VXLAN_UDP_DPORT;
        mutex_init(&mlxsw_sp->parsing.lock);
@@ -2939,6 +2940,7 @@ static void mlxsw_sp_parsing_init(struct mlxsw_sp *mlxsw_sp)
 static void mlxsw_sp_parsing_fini(struct mlxsw_sp *mlxsw_sp)
 {
        mutex_destroy(&mlxsw_sp->parsing.lock);
+       WARN_ON_ONCE(refcount_read(&mlxsw_sp->parsing.parsing_depth_ref));
 }
 
 struct mlxsw_sp_ipv6_addr_node {

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 48f1fa62a4fd492e68018e918afc193181ce215b..ab0aa1a61d4aaea0a3c4078433fe290f8ae16ee3 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -10313,11 +10313,23 @@ err_reg_write:
                                              old_inc_parsing_depth);
        return err;
 }
+
+static void mlxsw_sp_mp_hash_fini(struct mlxsw_sp *mlxsw_sp)
+{
+       bool old_inc_parsing_depth = mlxsw_sp->router->inc_parsing_depth;
+
+       mlxsw_sp_mp_hash_parsing_depth_adjust(mlxsw_sp, old_inc_parsing_depth,
+                                             false);
+}
 #else
 static int mlxsw_sp_mp_hash_init(struct mlxsw_sp *mlxsw_sp)
 {
        return 0;
 }
+
+static void mlxsw_sp_mp_hash_fini(struct mlxsw_sp *mlxsw_sp)
+{
+}
 #endif
 
 static int mlxsw_sp_dscp_init(struct mlxsw_sp *mlxsw_sp)
@@ -10547,6 +10559,7 @@ err_register_inet6addr_notifier:
 err_register_inetaddr_notifier:
        mlxsw_core_flush_owq();
 err_dscp_init:
+       mlxsw_sp_mp_hash_fini(mlxsw_sp);
 err_mp_hash_init:
        mlxsw_sp_neigh_fini(mlxsw_sp);
 err_neigh_init:
@@ -10587,6 +10600,7 @@ void mlxsw_sp_router_fini(struct mlxsw_sp *mlxsw_sp)
        unregister_inet6addr_notifier(&mlxsw_sp->router->inet6addr_nb);
        unregister_inetaddr_notifier(&mlxsw_sp->router->inetaddr_nb);
        mlxsw_core_flush_owq();
+       mlxsw_sp_mp_hash_fini(mlxsw_sp);
        mlxsw_sp_neigh_fini(mlxsw_sp);
        mlxsw_sp_lb_rif_fini(mlxsw_sp);
        mlxsw_sp_vrs_fini(mlxsw_sp);