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Message-Id: <20211024171757.3753288-7-vladimir.oltean@nxp.com>
Date: Sun, 24 Oct 2021 20:17:53 +0300
From: Vladimir Oltean <vladimir.oltean@....com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
Florian Fainelli <f.fainelli@...il.com>,
Andrew Lunn <andrew@...n.ch>,
Vivien Didelot <vivien.didelot@...il.com>,
Vladimir Oltean <olteanv@...il.com>,
UNGLinuxDriver@...rochip.com, DENG Qingfang <dqfext@...il.com>,
Kurt Kanzenbach <kurt@...utronix.de>,
Hauke Mehrtens <hauke@...ke-m.de>,
Woojung Huh <woojung.huh@...rochip.com>,
Sean Wang <sean.wang@...iatek.com>,
Landen Chao <Landen.Chao@...iatek.com>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
George McCollister <george.mccollister@...il.com>,
John Crispin <john@...ozen.org>,
Aleksander Jan Bajkowski <olek2@...pl>,
Egil Hjelmeland <privat@...l-hjelmeland.no>,
Oleksij Rempel <o.rempel@...gutronix.de>,
Prasanna Vengateshan <prasanna.vengateshan@...rochip.com>,
Ansuel Smith <ansuelsmth@...il.com>,
Alvin Šipraga <alsi@...g-olufsen.dk>,
Claudiu Manoil <claudiu.manoil@....com>
Subject: [PATCH v5 net-next 06/10] net: dsa: lantiq_gswip: serialize access to the PCE registers
The GSWIP switch accesses various bridging layer tables (VLANs, FDBs,
forwarding rules) indirectly through PCE registers. These hardware
accesses are non-atomic, being 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 registers using
its own locking scheme. This patch adds that.
Note that the driver also uses the gswip_pce_load_microcode() function
to load a static configuration for the packet classification engine into
a table using the same registers. It is currently not protected, but
since that configuration is only done from the dsa_switch_ops :: setup
method, there is no risk of it being concurrent with other operations.
Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
Acked-by: Hauke Mehrtens <hauke@...ke-m.de>
---
v3->v4: call mutex_init
v4->v5: slightly reword the commit message according to Hauke's indications
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 dbd4486a173f..1a96df70d1e8 100644
--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -276,6 +276,7 @@ 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 {
@@ -523,10 +524,14 @@ 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);
return err;
+ }
gswip_switch_w(priv, tbl->index, GSWIP_PCE_TBL_ADDR);
gswip_switch_mask(priv, GSWIP_PCE_TBL_CTRL_ADDR_MASK |
@@ -536,8 +541,10 @@ 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);
return err;
+ }
for (i = 0; i < ARRAY_SIZE(tbl->key); i++)
tbl->key[i] = gswip_switch_r(priv, GSWIP_PCE_TBL_KEY(i));
@@ -553,6 +560,8 @@ 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;
}
@@ -565,10 +574,14 @@ 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);
return err;
+ }
gswip_switch_w(priv, tbl->index, GSWIP_PCE_TBL_ADDR);
gswip_switch_mask(priv, GSWIP_PCE_TBL_CTRL_ADDR_MASK |
@@ -600,8 +613,12 @@ 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
@@ -2106,6 +2123,7 @@ static int gswip_probe(struct platform_device *pdev)
priv->ds->priv = priv;
priv->ds->ops = priv->hw_info->ops;
priv->dev = dev;
+ mutex_init(&priv->pce_table_lock);
version = gswip_switch_r(priv, GSWIP_VERSION);
np = dev->of_node;
--
2.25.1
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