linux.git/drivers/net/ntb_netdev.c, branch v7.1-rc2

net: ntb_netdev: add SPDX tag and remove boilerplate license text

2026-03-20T00:17:32+00:00

Add SPDX-License-Identifier tag to reflect the dual
GPL-2.0-only/BSD-3-Clause license, remove the redundant
boilerplate license text and contact information, keeping
only the driver description.

Signed-off-by: Oskar Ray-Frayssinet 
Acked-by: Dave Jiang 
Link: https://patch.msgid.link/20260318211153.9460-1-rayfraytech@gmail.com
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Support ethtool channels for multi-queue

2026-03-07T03:15:20+00:00

Support dynamic queue pair addition/removal via ethtool channels.
Use the combined channel count to control the number of netdev TX/RX
queues, each corresponding to a ntb_transport queue pair.

When the number of queues is reduced, tear down and free the removed
ntb_transport queue pairs (not just deactivate them) so other
ntb_transport clients can reuse the freed resources.

When the number of queues is increased, create additional queue pairs up
to NTB_NETDEV_MAX_QUEUES (=64). The effective limit is determined by the
underlying ntb_transport implementation and NTB hardware resources (the
number of MWs), so set_channels may return -ENOSPC if no more QPs can be
allocated.

Keep the default at one queue pair to preserve the previous behavior.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-5-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Factor out multi-queue helpers

2026-03-07T03:15:20+00:00

Implementing .set_channels will otherwise duplicate the same multi-queue
operations at multiple call sites. Factor out the following helpers:

  - ntb_netdev_update_carrier(): carrier is switched on when at least
                                 one QP link is up
  - ntb_netdev_queue_rx_drain(): drain and free all queued RX packets
                                 for one QP
  - ntb_netdev_queue_rx_fill():  prefill RX ring for one QP

No functional change.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-4-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Gate subqueue stop/wake by transport link

2026-03-07T03:15:20+00:00

When ntb_netdev is extended to multiple ntb_transport queue pairs, the
netdev carrier can be up as long as at least one QP link is up. In that
setup, a given QP may be link-down while the carrier remains on.

Make the link event handler start/stop the corresponding netdev TX
subqueue and drive carrier state based on whether any QP link is up.
Also guard subqueue wake/start points in the TX completion and timer
paths so a subqueue is not restarted while its QP link is down.

Stop all queues in ndo_open() and let the link event handler wake each
subqueue once ntb_transport link negotiation succeeds.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Introduce per-queue context

2026-03-07T03:15:20+00:00

Prepare ntb_netdev for multi-queue operation by moving queue-pair state
out of struct ntb_netdev.

Introduce struct ntb_netdev_queue to carry the ntb_transport_qp pointer,
the per-QP TX timer and queue id. Pass this object as the callback
context and convert the RX/TX handlers and link event path accordingly.

The probe path allocates a fixed upper bound for netdev queues while
instantiating only a single ntb_transport queue pair, preserving the
previous behavior. Also store client_dev for future queue pair
creation/removal via the ntb_transport API.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-2-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx()

2024-07-03T01:56:46+00:00

The following is emitted when using idxd (DSA) dmanegine as the data
mover for ntb_transport that ntb_netdev uses.

[74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526
[74412.556784] caller is netif_rx_internal+0x42/0x130
[74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5
[74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024
[74412.581699] Call Trace:
[74412.584514]  
[74412.586933]  dump_stack_lvl+0x55/0x70
[74412.591129]  check_preemption_disabled+0xc8/0xf0
[74412.596374]  netif_rx_internal+0x42/0x130
[74412.600957]  __netif_rx+0x20/0xd0
[74412.604743]  ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev]
[74412.610985]  ntb_complete_rxc+0xed/0x140 [ntb_transport]
[74412.617010]  ntb_rx_copy_callback+0x53/0x80 [ntb_transport]
[74412.623332]  idxd_dma_complete_txd+0xe3/0x160 [idxd]
[74412.628963]  idxd_wq_thread+0x1a6/0x2b0 [idxd]
[74412.634046]  irq_thread_fn+0x21/0x60
[74412.638134]  ? irq_thread+0xa8/0x290
[74412.642218]  irq_thread+0x1a0/0x290
[74412.646212]  ? __pfx_irq_thread_fn+0x10/0x10
[74412.651071]  ? __pfx_irq_thread_dtor+0x10/0x10
[74412.656117]  ? __pfx_irq_thread+0x10/0x10
[74412.660686]  kthread+0x100/0x130
[74412.664384]  ? __pfx_kthread+0x10/0x10
[74412.668639]  ret_from_fork+0x31/0x50
[74412.672716]  ? __pfx_kthread+0x10/0x10
[74412.676978]  ret_from_fork_asm+0x1a/0x30
[74412.681457]  

The cause is due to the idxd driver interrupt completion handler uses
threaded interrupt and the threaded handler is not hard or soft interrupt
context. However __netif_rx() can only be called from interrupt context.
Change the call to netif_rx() in order to allow completion via normal
context for dmaengine drivers that utilize threaded irq handling.

While the following commit changed from netif_rx() to __netif_rx(),
baebdf48c360 ("net: dev: Makes sure netif_rx() can be invoked in any context."),
the change should've been a noop instead. However, the code precedes this
fix should've been using netif_rx_ni() or netif_rx_any_context().

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Reported-by: Jerry Dai 
Tested-by: Jerry Dai 
Signed-off-by: Dave Jiang 
Link: https://patch.msgid.link/20240701181538.3799546-1-dave.jiang@intel.com
Signed-off-by: Jakub Kicinski

net: annotate writes on dev->mtu from ndo_change_mtu()

2024-05-07T23:19:14+00:00

Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet 
Reported-by: Simon Horman 
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller 
Reviewed-by: Sabrina Dubroca 
Reviewed-by: Simon Horman 
Acked-by: Shannon Nelson 
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

ntb_netdev: Fix module_init problem

2023-07-08T15:03:53+00:00

With both the ntb_transport_init and the ntb_netdev_init_module routines in the
module_init init group, the ntb_netdev_init_module routine can be called before
the ntb_transport_init routine that it depends on is called.  To assure the
proper initialization order put ntb_netdev_init_module in the late_initcall
group.

Fixes runtime errors where the ntb_netdev_init_module call fails with ENODEV.

Signed-off-by: Geoff Levand 
Reviewed-by: Dave Jiang 
Signed-off-by: Jon Mason