Messages in this thread Patch in this message | | | Date | Mon, 15 Nov 2021 20:41:17 -0500 | From | Sasha Levin <> | Subject | Re: [PATCH 5.15 291/917] net: dsa: lantiq_gswip: serialize access to the PCE table |
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On Mon, Nov 15, 2021 at 11:35:47PM +0000, Vladimir Oltean wrote: >On Mon, Nov 15, 2021 at 05:56:26PM +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 dbd4486a173ff..1a96df70d1e85 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; >> -- >> 2.33.0 >> >> >> > >As discussed on the v5.14 backport, this patch can be dropped.
Dropped, thanks!
-- Thanks, Sasha
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