kernel/linux.git/include/linux/dsa/8021q.h, branch v6.19.12

net: dsa: prepare 'dsa_tag_8021q_bridge_join' for standalone use

2024-07-15T13:55:16+00:00

The 'dsa_tag_8021q_bridge_join' could be used as a generic implementation of the 'ds->ops->port_bridge_join()' function. However, it is necessary to synchronize their arguments. This patch also moves the 'tx_fwd_offload' flag configuration line into 'dsa_tag_8021q_bridge_join' body. Currently, every (sja1105) driver sets it, and the future vsc73xx implementation will also need it for simplification. Suggested-by: Vladimir Oltean Signed-off-by: Pawel Dembicki Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20240713211620.1125910-11-paweldembicki@gmail.com Signed-off-by: Jakub Kicinski

net: dsa: Define max num of bridges in tag8021q implementation

2024-07-15T13:55:16+00:00

Max number of bridges in tag8021q implementation is strictly limited by VBID size: 3 bits. But zero is reserved and only 7 values can be used. This patch adds define which describe maximum possible value. Suggested-by: Vladimir Oltean Signed-off-by: Pawel Dembicki Reviewed-by: Florian Fainelli Reviewed-by: Linus Walleij Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20240713211620.1125910-10-paweldembicki@gmail.com Signed-off-by: Jakub Kicinski

net: dsa: move tag_8021q headers to their proper place

2022-11-23T04:41:53+00:00

tag_8021q definitions are all over the place. Some are exported to linux/dsa/8021q.h (visible by DSA core, taggers, switch drivers and everyone else), and some are in dsa_priv.h. Move the structures that don't need external visibility into tag_8021q.c, and the ones which don't need the world or switch drivers to see them into tag_8021q.h. We also have the tag_8021q.h inclusion from switch.c, which is basically the entire reason why tag_8021q.c was built into DSA in commit 8b6e638b4be2 ("net: dsa: build tag_8021q.c as part of DSA core"). I still don't know how to better deal with that, so leave it alone. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski

net: dsa: tag_8021q: rename dsa_8021q_bridge_tx_fwd_offload_vid

2022-02-27T11:06:14+00:00

The dsa_8021q_bridge_tx_fwd_offload_vid is no longer used just for bridge TX forwarding offload, it is the private VLAN reserved for VLAN-unaware bridging in a way that is compatible with FDB isolation. So just rename it dsa_tag_8021q_bridge_vid. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: tag_8021q: merge RX and TX VLANs

2022-02-27T11:06:14+00:00

In the old Shared VLAN Learning mode of operation that tag_8021q previously used for forwarding, we needed to have distinct concepts for an RX and a TX VLAN. An RX VLAN could be installed on all ports that were members of a given bridge, so that autonomous forwarding could still work, while a TX VLAN was dedicated for precise packet steering, so it just contained the CPU port and one egress port. Now that tag_8021q uses Independent VLAN Learning and imprecise RX/TX all over, those lines have been blurred and we no longer have the need to do precise TX towards a port that is in a bridge. As for standalone ports, it is fine to use the same VLAN ID for both RX and TX. This patch changes the tag_8021q format by shifting the VLAN range it reserves, and halving it. Previously, our DIR bits were encoding the VLAN direction (RX/TX) and were set to either 1 or 2. This meant that tag_8021q reserved 2K VLANs, or 50% of the available range. Change the DIR bits to a hardcoded value of 3 now, which makes tag_8021q reserve only 1K VLANs, and a different range now (the last 1K). This is done so that we leave the old format in place in case we need to return to it. In terms of code, the vid_is_dsa_8021q_rxvlan and vid_is_dsa_8021q_txvlan functions go away. Any vid_is_dsa_8021q is both a TX and an RX VLAN, and they are no longer distinct. For example, felix which did different things for different VLAN types, now needs to handle the RX and the TX logic for the same VLAN. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: tag_8021q: add support for imprecise RX based on the VBID

2022-02-27T11:06:13+00:00

The sja1105 switch can't populate the PORT field of the tag_8021q header when sending a frame to the CPU with a non-zero VBID. Similar to dsa_find_designated_bridge_port_by_vid() which performs imprecise RX for VLAN-aware bridges, let's introduce a helper in tag_8021q for performing imprecise RX based on the VLAN that it has allocated for a VLAN-unaware bridge. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: tag_8021q: replace the SVL bridging with VLAN-unaware IVL bridging

2022-02-27T11:06:13+00:00

For VLAN-unaware bridging, tag_8021q uses something perhaps a bit too tied with the sja1105 switch: each port uses the same pvid which is also used for standalone operation (a unique one from which the source port and device ID can be retrieved when packets from that port are forwarded to the CPU). Since each port has a unique pvid when performing autonomous forwarding, the switch must be configured for Shared VLAN Learning (SVL) such that the VLAN ID itself is ignored when performing FDB lookups. Without SVL, packets would always be flooded, since FDB lookup in the source port's VLAN would never find any entry. First of all, to make tag_8021q more palatable to switches which might not support Shared VLAN Learning, let's just use a common VLAN for all ports that are under the same bridge. Secondly, using Shared VLAN Learning means that FDB isolation can never be enforced. But if all ports under the same VLAN-unaware bridge share the same VLAN ID, it can. The disadvantage is that the CPU port can no longer perform precise source port identification for these packets. But at least we have a mechanism which has proven to be adequate for that situation: imprecise RX (dsa_find_designated_bridge_port_by_vid), which is what we use for termination on VLAN-aware bridges. The VLAN ID that VLAN-unaware bridges will use with tag_8021q is the same one as we were previously using for imprecise TX (bridge TX forwarding offload). It is already allocated, it is just a matter of using it. Note that because now all ports under the same bridge share the same VLAN, the complexity of performing a tag_8021q bridge join decreases dramatically. We no longer have to install the RX VLAN of a newly joining port into the port membership of the existing bridge ports. The newly joining port just becomes a member of the VLAN corresponding to that bridge, and the other ports are already members of it from when they joined the bridge themselves. So forwarding works properly. This means that we can unhook dsa_tag_8021q_bridge_{join,leave} from the cross-chip notifier level dsa_switch_bridge_{join,leave}. We can put these calls directly into the sja1105 driver. With this new mode of operation, a port controlled by tag_8021q can have two pvids whereas before it could only have one. The pvid for standalone operation is different from the pvid used for VLAN-unaware bridging. This is done, again, so that FDB isolation can be enforced. Let tag_8021q manage this by deleting the standalone pvid when a port joins a bridge, and restoring it when it leaves it. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: keep the bridge_dev and bridge_num as part of the same structure

2021-12-08T22:31:16+00:00

The main desire behind this is to provide coherent bridge information to the fast path without locking. For example, right now we set dp->bridge_dev and dp->bridge_num from separate code paths, it is theoretically possible for a packet transmission to read these two port properties consecutively and find a bridge number which does not correspond with the bridge device. Another desire is to start passing more complex bridge information to dsa_switch_ops functions. For example, with FDB isolation, it is expected that drivers will need to be passed the bridge which requested an FDB/MDB entry to be offloaded, and along with that bridge_dev, the associated bridge_num should be passed too, in case the driver might want to implement an isolation scheme based on that number. We already pass the {bridge_dev, bridge_num} pair to the TX forwarding offload switch API, however we'd like to remove that and squash it into the basic bridge join/leave API. So that means we need to pass this pair to the bridge join/leave API. During dsa_port_bridge_leave, first we unset dp->bridge_dev, then we call the driver's .port_bridge_leave with what used to be our dp->bridge_dev, but provided as an argument. When bridge_dev and bridge_num get folded into a single structure, we need to preserve this behavior in dsa_port_bridge_leave: we need a copy of what used to be in dp->bridge. Switch drivers check bridge membership by comparing dp->bridge_dev with the provided bridge_dev, but now, if we provide the struct dsa_bridge as a pointer, they cannot keep comparing dp->bridge to the provided pointer, since this only points to an on-stack copy. To make this obvious and prevent driver writers from forgetting and doing stupid things, in this new API, the struct dsa_bridge is provided as a full structure (not very large, contains an int and a pointer) instead of a pointer. An explicit comparison function needs to be used to determine bridge membership: dsa_port_offloads_bridge(). Signed-off-by: Vladimir Oltean Reviewed-by: Alvin Šipraga Signed-off-by: Jakub Kicinski

net: dsa: make dp->bridge_num one-based

2021-12-08T22:31:14+00:00

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 Reviewed-by: Alvin Šipraga Signed-off-by: Jakub Kicinski

net: dsa: tag_8021q: make dsa_8021q_{rx,tx}_vid take dp as argument

2021-10-21T11:44:07+00:00

Pass a single argument to dsa_8021q_rx_vid and dsa_8021q_tx_vid that contains the necessary information from the two arguments that are currently provided: the switch and the port number. Also rename those functions so that they have a dsa_port_* prefix, since they operate on a struct dsa_port *. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller