kernel/linux.git/drivers/net/ntb_netdev.c, branch v6.18.48

NTB: ntb_netdev: Preserve RX queue depth on allocation failure

2026-08-23T12:27:06+00:00

commit d2121faf133ac3bf9531b53a7e21273649a08517 upstream. ntb_netdev_rx_handler() hands the received skb to the network stack before allocating its replacement. If the allocation fails, nothing is reposted. Every failure therefore takes one buffer out of the RX queue while the interface remains up, and enough failures eventually stall reception. A retry path could refill the queue later, but ntb_netdev has none. Allocate the replacement first instead. If that fails, drop the packet and repost the same skb. This keeps the queue full and lets packet delivery resume as soon as memory is available again. Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device") Cc: stable@vger.kernel.org Signed-off-by: Koichiro Den Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20260806032537.3526498-1-den@valinux.co.jp Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: ntb_netdev: Introduce per-queue context

2026-08-23T12:27:06+00:00

commit ee970634c7773f248a0a27d8a645500371ae5249 upstream. 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 Stable-dep-of: d2121faf133a ("NTB: ntb_netdev: Preserve RX queue depth on allocation failure") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

ntb_netdev: Use dev_kfree_skb_any() in interrupt context

2022-12-12T20:56:37+00:00

TX/RX callback handlers (ntb_netdev_tx_handler(), ntb_netdev_rx_handler()) can be called in interrupt context via the DMA framework when the respective DMA operations have completed. As such, any calls by these routines to free skb's, should use the interrupt context safe dev_kfree_skb_any() function. Previously, these callback handlers would call the interrupt unsafe version of dev_kfree_skb(). This has not presented an issue on Intel IOAT DMA engines as that driver utilizes tasklets rather than a hard interrupt handler, like the AMD PTDMA DMA driver. On AMD systems, a kernel WARNING message is encountered, which is being issued from skb_release_head_state() due to in_hardirq() being true. Besides the user visible WARNING from the kernel, the other symptom of this bug was that TCP/IP performance across the ntb_netdev interface was very poor, i.e. approximately an order of magnitude below what was expected. With the repair to use dev_kfree_skb_any(), kernel WARNINGs from skb_release_head_state() ceased and TCP/IP performance, as measured by iperf, was on par with expected results, approximately 20 Gb/s on AMD Milan based server. Note that this performance is comparable with Intel based servers. Fixes: 765ccc7bc3d91 ("ntb_netdev: correct skb leak") Fixes: 548c237c0a997 ("net: Add support for NTB virtual ethernet device") Signed-off-by: Eric Pilmore Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20221209000659.8318-1-epilmore@gigaio.com Signed-off-by: Jakub Kicinski

net: net_netdev: Fix error handling in ntb_netdev_init_module()

2022-11-28T11:07:13+00:00

The ntb_netdev_init_module() returns the ntb_transport_register_client() directly without checking its return value, if ntb_transport_register_client() failed, the NTB client device is not unregistered. Fix by unregister NTB client device when ntb_transport_register_client() failed. Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device") Signed-off-by: Yuan Can Signed-off-by: David S. Miller

net: move from strlcpy with unused retval to strscpy

2022-08-31T21:11:07+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Acked-by: Marc Kleine-Budde # for CAN Link: https://lore.kernel.org/r/20220830201457.7984-1-wsa+renesas@sang-engineering.com Signed-off-by: Jakub Kicinski