| Message ID | 20210703115705.1034112-7-vladimir.oltean@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Allow forwarding for the software bridge data path to be offloaded to capable devices | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | success | CCed 3 of 3 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 4897 this patch: 4897 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 13 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 4956 this patch: 4956 |
| netdev/header_inline | success | Link |
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 16c88e416693..d43f6ddd12a1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3697,10 +3697,10 @@ static inline void netdev_reset_queue(struct net_device *dev_queue) */ static inline u16 netdev_cap_txqueue(struct net_device *dev, u16 queue_index) { - if (unlikely(queue_index >= dev->real_num_tx_queues)) { - net_warn_ratelimited("%s selects TX queue %d, but real number of TX queues is %d\n", + if (unlikely(queue_index >= dev->num_tx_queues)) { + net_warn_ratelimited("%s selects TX queue %d, but number of TX queues is %d\n", dev->name, queue_index, - dev->real_num_tx_queues); + dev->num_tx_queues); return 0; }
When using a bridge upper as a subordinate device, switchdev interfaces must allocate a TX queue for it, in order to have the information needed in .ndo_start_xmit() whether the skb comes from the bridge or not. The dedicated TX queue has the ->sb_dev pointer pointing to the bridge device, and the only assumption that can be made is that any skb on that queue must be coming from the bridge. So no other skbs can be sent on that. The default netdev_pick_tx() -> skb_tx_hash() policy hashes between TX queues of the same priority. To make the scheme work, switchdev drivers offloading a bridge need to implement their own .ndo_select_queue() which selects the dedicated TX queue for packets coming from the sb_dev, and lets netdev_pick_tx() choose from the rest of the TX queues for the rest. The implication is that the dedicated TX queue for the sb_dev must be outside of the dev->num_real_tx_queues range, because otherwise, netdev_pick_tx() might choose that TX queue for packets which aren't actually coming from our sb_dev and therefore the assumption made in the driver's .ndo_start_xmit() would be wrong. This patch lifts the restriction in netdev_core_pick_tx() which says that the dedicated TX queue for the sb_dev cannot be larger than the num_real_tx_queues. With this, netdev_pick_tx() can safely pick between the non-dedicated TX queues. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- include/linux/netdevice.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)