On Mon, Nov 15, 2021 at 06:01:33PM +0100, Greg Kroah-Hartman wrote:
From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 49753a75b9a32de4c0393bb8d1e51ea223fda8e4 ]
Looking at the code, the GSWIP switch appears to hold bridging service structures (VLANs, FDBs, forwarding rules) in PCE table entries. Hardware access to the PCE table is non-atomic, and is comprised of several register reads and writes.
These accesses are currently serialized by the rtnl_lock, but DSA is changing its driver API and that lock will no longer be held when calling ->port_fdb_add() and ->port_fdb_del().
So this driver needs to serialize the access to the PCE table using its own locking scheme. This patch adds that.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Acked-by: Hauke Mehrtens hauke@hauke-m.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org
drivers/net/dsa/lantiq_gswip.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c index 60e36f46f8abe..d612ef8648baa 100644 --- a/drivers/net/dsa/lantiq_gswip.c +++ b/drivers/net/dsa/lantiq_gswip.c @@ -274,6 +274,7 @@ struct gswip_priv { int num_gphy_fw; struct gswip_gphy_fw *gphy_fw; u32 port_vlan_filter;
- struct mutex pce_table_lock;
}; struct gswip_pce_table_entry { @@ -521,10 +522,14 @@ static int gswip_pce_table_entry_read(struct gswip_priv *priv, u16 addr_mode = tbl->key_mode ? GSWIP_PCE_TBL_CTRL_OPMOD_KSRD : GSWIP_PCE_TBL_CTRL_OPMOD_ADRD;
- mutex_lock(&priv->pce_table_lock);
- err = gswip_switch_r_timeout(priv, GSWIP_PCE_TBL_CTRL, GSWIP_PCE_TBL_CTRL_BAS);
- if (err)
- if (err) {
mutex_unlock(&priv->pce_table_lock);- }
gswip_switch_w(priv, tbl->index, GSWIP_PCE_TBL_ADDR); gswip_switch_mask(priv, GSWIP_PCE_TBL_CTRL_ADDR_MASK | @@ -534,8 +539,10 @@ static int gswip_pce_table_entry_read(struct gswip_priv *priv, err = gswip_switch_r_timeout(priv, GSWIP_PCE_TBL_CTRL, GSWIP_PCE_TBL_CTRL_BAS);
- if (err)
- if (err) {
mutex_unlock(&priv->pce_table_lock);- }
for (i = 0; i < ARRAY_SIZE(tbl->key); i++) tbl->key[i] = gswip_switch_r(priv, GSWIP_PCE_TBL_KEY(i)); @@ -551,6 +558,8 @@ static int gswip_pce_table_entry_read(struct gswip_priv *priv, tbl->valid = !!(crtl & GSWIP_PCE_TBL_CTRL_VLD); tbl->gmap = (crtl & GSWIP_PCE_TBL_CTRL_GMAP_MASK) >> 7;
- mutex_unlock(&priv->pce_table_lock);
- return 0;
} @@ -563,10 +572,14 @@ static int gswip_pce_table_entry_write(struct gswip_priv *priv, u16 addr_mode = tbl->key_mode ? GSWIP_PCE_TBL_CTRL_OPMOD_KSWR : GSWIP_PCE_TBL_CTRL_OPMOD_ADWR;
- mutex_lock(&priv->pce_table_lock);
- err = gswip_switch_r_timeout(priv, GSWIP_PCE_TBL_CTRL, GSWIP_PCE_TBL_CTRL_BAS);
- if (err)
- if (err) {
mutex_unlock(&priv->pce_table_lock);- }
gswip_switch_w(priv, tbl->index, GSWIP_PCE_TBL_ADDR); gswip_switch_mask(priv, GSWIP_PCE_TBL_CTRL_ADDR_MASK | @@ -598,8 +611,12 @@ static int gswip_pce_table_entry_write(struct gswip_priv *priv, crtl |= GSWIP_PCE_TBL_CTRL_BAS; gswip_switch_w(priv, crtl, GSWIP_PCE_TBL_CTRL);
- return gswip_switch_r_timeout(priv, GSWIP_PCE_TBL_CTRL,
GSWIP_PCE_TBL_CTRL_BAS);
- err = gswip_switch_r_timeout(priv, GSWIP_PCE_TBL_CTRL,
GSWIP_PCE_TBL_CTRL_BAS);- mutex_unlock(&priv->pce_table_lock);
- return err;
} /* Add the LAN port into a bridge with the CPU port by @@ -2020,6 +2037,7 @@ static int gswip_probe(struct platform_device *pdev) priv->ds->priv = priv; priv->ds->ops = &gswip_switch_ops; priv->dev = dev;
- mutex_init(&priv->pce_table_lock); version = gswip_switch_r(priv, GSWIP_VERSION);
/* bring up the mdio bus */ -- 2.33.0
As discussed on the v5.14 backport, this patch can be dropped. Same thing for the 5.10 version of the backport.