Re: [RFC PATCH net-next 1/6] net: dsa: make dp->bridge_num one-based
From: Alvin Šipraga <hidden>
Date: 2021-11-11 12:24:51
On 10/26/21 18:26, Vladimir Oltean wrote:
I have seen too many bugs already due to the fact that we must encode an
invalid dp->bridge_num as a negative value, because the natural tendency
is to check that invalid value using (!dp->bridge_num). Latest example
can be seen in commit 1bec0f05062c ("net: dsa: fix bridge_num not
getting cleared after ports leaving the bridge").
Convert the existing users to assume that dp->bridge_num == 0 is the
encoding for invalid, and valid bridge numbers start from 1.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---Reviewed-by: Alvin Šipraga <redacted> Small remark inline.
quoted hunk ↗ jump to hunk
drivers/net/dsa/mv88e6xxx/chip.c | 12 ++++++------ include/linux/dsa/8021q.h | 6 +++--- include/net/dsa.h | 6 +++--- net/dsa/dsa2.c | 24 ++++++++++++------------ net/dsa/dsa_priv.h | 5 +++-- net/dsa/port.c | 11 ++++++----- net/dsa/tag_8021q.c | 12 +++++++----- net/dsa/tag_dsa.c | 2 +- 8 files changed, 41 insertions(+), 37 deletions(-)diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 14c678a9e41b..0d0ccb7f8ccd 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c@@ -1247,10 +1247,10 @@ static u16 mv88e6xxx_port_vlan(struct mv88e6xxx_chip *chip, int dev, int port) /* dev is a virtual bridge */ } else { list_for_each_entry(dp, &dst->ports, list) { - if (dp->bridge_num < 0) + if (!dp->bridge_num) continue; - if (dp->bridge_num + 1 + dst->last_switch != dev) + if (dp->bridge_num + dst->last_switch != dev) continue; br = dp->bridge_dev;@@ -2524,9 +2524,9 @@ static void mv88e6xxx_crosschip_bridge_leave(struct dsa_switch *ds, * physical switches, so start from beyond that range. */ static int mv88e6xxx_map_virtual_bridge_to_pvt(struct dsa_switch *ds, - int bridge_num) + unsigned int bridge_num) { - u8 dev = bridge_num + ds->dst->last_switch + 1; + u8 dev = bridge_num + ds->dst->last_switch; struct mv88e6xxx_chip *chip = ds->priv; int err;@@ -2539,14 +2539,14 @@ static int mv88e6xxx_map_virtual_bridge_to_pvt(struct dsa_switch *ds, static int mv88e6xxx_bridge_tx_fwd_offload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num) + unsigned int bridge_num) { return mv88e6xxx_map_virtual_bridge_to_pvt(ds, bridge_num); } static void mv88e6xxx_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num) + unsigned int bridge_num) { int err;diff --git a/include/linux/dsa/8021q.h b/include/linux/dsa/8021q.h index 254b165f2b44..0af4371fbebb 100644 --- a/include/linux/dsa/8021q.h +++ b/include/linux/dsa/8021q.h@@ -38,13 +38,13 @@ void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id); int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num); + unsigned int bridge_num); void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num); + unsigned int bridge_num); -u16 dsa_8021q_bridge_tx_fwd_offload_vid(int bridge_num); +u16 dsa_8021q_bridge_tx_fwd_offload_vid(unsigned int bridge_num); u16 dsa_tag_8021q_tx_vid(const struct dsa_port *dp);diff --git a/include/net/dsa.h b/include/net/dsa.h index badd214f7470..56a90f05df49 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h@@ -257,7 +257,7 @@ struct dsa_port { bool learning; u8 stp_state; struct net_device *bridge_dev; - int bridge_num; + unsigned int bridge_num; struct devlink_port devlink_port; bool devlink_port_setup; struct phylink *pl;@@ -752,11 +752,11 @@ struct dsa_switch_ops { /* Called right after .port_bridge_join() */ int (*port_bridge_tx_fwd_offload)(struct dsa_switch *ds, int port, struct net_device *bridge, - int bridge_num); + unsigned int bridge_num); /* Called right before .port_bridge_leave() */ void (*port_bridge_tx_fwd_unoffload)(struct dsa_switch *ds, int port, struct net_device *bridge, - int bridge_num); + unsigned int bridge_num); void (*port_stp_state_set)(struct dsa_switch *ds, int port, u8 state); void (*port_fast_age)(struct dsa_switch *ds, int port);diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index 826957b6442b..9606e56710a5 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c@@ -141,23 +141,23 @@ static int dsa_bridge_num_find(const struct net_device *bridge_dev) */ list_for_each_entry(dst, &dsa_tree_list, list) list_for_each_entry(dp, &dst->ports, list) - if (dp->bridge_dev == bridge_dev && - dp->bridge_num != -1) + if (dp->bridge_dev == bridge_dev && dp->bridge_num) return dp->bridge_num; - return -1; + return 0; } -int dsa_bridge_num_get(const struct net_device *bridge_dev, int max) +unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max) { - int bridge_num = dsa_bridge_num_find(bridge_dev); + unsigned int bridge_num = dsa_bridge_num_find(bridge_dev); - if (bridge_num < 0) { + if (!bridge_num) { /* First port that offloads TX forwarding for this bridge */
Perhaps you want to update this comment in patch 2/6, since bridge_num is no longer just about TX forwarding offload.
quoted hunk ↗ jump to hunk
- bridge_num = find_first_zero_bit(&dsa_fwd_offloading_bridges, - DSA_MAX_NUM_OFFLOADING_BRIDGES); + bridge_num = find_next_zero_bit(&dsa_fwd_offloading_bridges, + DSA_MAX_NUM_OFFLOADING_BRIDGES, + 1); if (bridge_num >= max) - return -1; + return 0; set_bit(bridge_num, &dsa_fwd_offloading_bridges); }@@ -165,12 +165,13 @@ int dsa_bridge_num_get(const struct net_device *bridge_dev, int max) return bridge_num; } -void dsa_bridge_num_put(const struct net_device *bridge_dev, int bridge_num) +void dsa_bridge_num_put(const struct net_device *bridge_dev, + unsigned int bridge_num) { /* Check if the bridge is still in use, otherwise it is time * to clean it up so we can reuse this bridge_num later. */ - if (dsa_bridge_num_find(bridge_dev) < 0) + if (!dsa_bridge_num_find(bridge_dev)) clear_bit(bridge_num, &dsa_fwd_offloading_bridges); }@@ -1184,7 +1185,6 @@ static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index) dp->ds = ds; dp->index = index; - dp->bridge_num = -1; INIT_LIST_HEAD(&dp->list); list_add_tail(&dp->list, &dst->ports);diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index a5c9bc7b66c6..2a64c41813bf 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h@@ -546,8 +546,9 @@ int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst, struct net_device *master, const struct dsa_device_ops *tag_ops, const struct dsa_device_ops *old_tag_ops); -int dsa_bridge_num_get(const struct net_device *bridge_dev, int max); -void dsa_bridge_num_put(const struct net_device *bridge_dev, int bridge_num); +unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max); +void dsa_bridge_num_put(const struct net_device *bridge_dev, + unsigned int bridge_num); /* tag_8021q.c */ int dsa_tag_8021q_bridge_join(struct dsa_switch *ds,diff --git a/net/dsa/port.c b/net/dsa/port.c index c0e630f7f0bd..1772817a1214 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c@@ -273,14 +273,14 @@ static void dsa_port_switchdev_unsync_attrs(struct dsa_port *dp) static void dsa_port_bridge_tx_fwd_unoffload(struct dsa_port *dp, struct net_device *bridge_dev) { - int bridge_num = dp->bridge_num; + unsigned int bridge_num = dp->bridge_num; struct dsa_switch *ds = dp->ds; /* No bridge TX forwarding offload => do nothing */ - if (!ds->ops->port_bridge_tx_fwd_unoffload || dp->bridge_num == -1) + if (!ds->ops->port_bridge_tx_fwd_unoffload || !dp->bridge_num) return; - dp->bridge_num = -1; + dp->bridge_num = 0; dsa_bridge_num_put(bridge_dev, bridge_num);@@ -295,14 +295,15 @@ static bool dsa_port_bridge_tx_fwd_offload(struct dsa_port *dp, struct net_device *bridge_dev) { struct dsa_switch *ds = dp->ds; - int bridge_num, err; + unsigned int bridge_num; + int err; if (!ds->ops->port_bridge_tx_fwd_offload) return false; bridge_num = dsa_bridge_num_get(bridge_dev, ds->num_fwd_offloading_bridges); - if (bridge_num < 0) + if (!bridge_num) return false; dp->bridge_num = bridge_num;diff --git a/net/dsa/tag_8021q.c b/net/dsa/tag_8021q.c index 72cac2c0af7b..df59f16436a5 100644 --- a/net/dsa/tag_8021q.c +++ b/net/dsa/tag_8021q.c@@ -67,10 +67,12 @@ #define DSA_8021Q_PORT(x) (((x) << DSA_8021Q_PORT_SHIFT) & \ DSA_8021Q_PORT_MASK) -u16 dsa_8021q_bridge_tx_fwd_offload_vid(int bridge_num) +u16 dsa_8021q_bridge_tx_fwd_offload_vid(unsigned int bridge_num) { - /* The VBID value of 0 is reserved for precise TX */ - return DSA_8021Q_DIR_TX | DSA_8021Q_VBID(bridge_num + 1); + /* The VBID value of 0 is reserved for precise TX, but it is also + * reserved/invalid for the bridge_num, so all is well. + */ + return DSA_8021Q_DIR_TX | DSA_8021Q_VBID(bridge_num); } EXPORT_SYMBOL_GPL(dsa_8021q_bridge_tx_fwd_offload_vid);@@ -409,7 +411,7 @@ int dsa_tag_8021q_bridge_leave(struct dsa_switch *ds, int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num) + unsigned int bridge_num) { u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num);@@ -420,7 +422,7 @@ EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_tx_fwd_offload); void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port, struct net_device *br, - int bridge_num) + unsigned int bridge_num) { u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num);diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c index b3da4b2ea11c..a7d70ae7cc97 100644 --- a/net/dsa/tag_dsa.c +++ b/net/dsa/tag_dsa.c@@ -140,7 +140,7 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, * packets on behalf of a virtual switch device with an index * past the physical switches. */ - tag_dev = dst->last_switch + 1 + dp->bridge_num; + tag_dev = dst->last_switch + dp->bridge_num; tag_port = 0; } else { cmd = DSA_CMD_FROM_CPU;