• Dave Jiang's avatar
    net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx() · e15a5d82
    Dave Jiang authored
    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]  <TASK>
    [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]  </TASK>
    
    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(),
    baebdf48 ("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: 548c237c ("net: Add support for NTB virtual ethernet device")
    Reported-by: default avatarJerry Dai <jerry.dai@intel.com>
    Tested-by: default avatarJerry Dai <jerry.dai@intel.com>
    Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
    Link: https://patch.msgid.link/20240701181538.3799546-1-dave.jiang@intel.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    e15a5d82
ntb_netdev.c 12.3 KB