From: Ido Schimmel <idosch@nvidia.com>
Date: Mon, 13 Mar 2023 18:21:24 +0100
Subject: [PATCH] mlxsw: spectrum: Fix incorrect parsing depth after reload
References: bsc#1012628
Patch-mainline: 6.2.8
Git-commit: 35c356924fe3669dfbb1185607ce3b37f70bfa80

[ Upstream commit 35c356924fe3669dfbb1185607ce3b37f70bfa80 ]

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: 2d91f0803b84 ("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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c     |  2 ++
 .../net/ethernet/mellanox/mlxsw/spectrum_router.c  | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index f5b2d965..12540feb 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2937,6 +2937,7 @@ 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);
@@ -2945,6 +2946,7 @@ 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 09e32778..4a73e2fe 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -10381,11 +10381,23 @@ static int mlxsw_sp_mp_hash_init(struct mlxsw_sp *mlxsw_sp)
 					      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)
@@ -10615,6 +10627,7 @@ int mlxsw_sp_router_init(struct mlxsw_sp *mlxsw_sp,
 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:
@@ -10655,6 +10668,7 @@ 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);
-- 
2.35.3