• Konstantin Khorenko's avatar
    qed: Fix scheduling in a tasklet while getting stats · e346e231
    Konstantin Khorenko authored
    Here we've got to a situation when tasklet called usleep_range() in PTT
    acquire logic, thus welcome to the "scheduling while atomic" BUG().
    
      BUG: scheduling while atomic: swapper/24/0/0x00000100
    
       [<ffffffffb41c6199>] schedule+0x29/0x70
       [<ffffffffb41c5512>] schedule_hrtimeout_range_clock+0xb2/0x150
       [<ffffffffb41c55c3>] schedule_hrtimeout_range+0x13/0x20
       [<ffffffffb41c3bcf>] usleep_range+0x4f/0x70
       [<ffffffffc08d3e58>] qed_ptt_acquire+0x38/0x100 [qed]
       [<ffffffffc08eac48>] _qed_get_vport_stats+0x458/0x580 [qed]
       [<ffffffffc08ead8c>] qed_get_vport_stats+0x1c/0xd0 [qed]
       [<ffffffffc08dffd3>] qed_get_protocol_stats+0x93/0x100 [qed]
                            qed_mcp_send_protocol_stats
                case MFW_DRV_MSG_GET_LAN_STATS:
                case MFW_DRV_MSG_GET_FCOE_STATS:
                case MFW_DRV_MSG_GET_ISCSI_STATS:
                case MFW_DRV_MSG_GET_RDMA_STATS:
       [<ffffffffc08e36d8>] qed_mcp_handle_events+0x2d8/0x890 [qed]
                            qed_int_assertion
                            qed_int_attentions
       [<ffffffffc08d9490>] qed_int_sp_dpc+0xa50/0xdc0 [qed]
       [<ffffffffb3aa7623>] tasklet_action+0x83/0x140
       [<ffffffffb41d9125>] __do_softirq+0x125/0x2bb
       [<ffffffffb41d560c>] call_softirq+0x1c/0x30
       [<ffffffffb3a30645>] do_softirq+0x65/0xa0
       [<ffffffffb3aa78d5>] irq_exit+0x105/0x110
       [<ffffffffb41d8996>] do_IRQ+0x56/0xf0
    
    Fix this by making caller to provide the context whether it could be in
    atomic context flow or not when getting stats from QED driver.
    QED driver based on the context provided decide to schedule out or not
    when acquiring the PTT BAR window.
    
    We faced the BUG_ON() while getting vport stats, but according to the
    code same issue could happen for fcoe and iscsi statistics as well, so
    fixing them too.
    
    Fixes: 6c754246 ("qed: Add support for NCSI statistics.")
    Fixes: 1e128c81 ("qed: Add support for hardware offloaded FCoE.")
    Fixes: 2f2b2614 ("qed: Provide iSCSI statistics to management")
    Cc: Sudarsana Kalluru <skalluru@marvell.com>
    Cc: David Miller <davem@davemloft.net>
    Cc: Manish Chopra <manishc@marvell.com>
    Signed-off-by: default avatarKonstantin Khorenko <khorenko@virtuozzo.com>
    Reviewed-by: default avatarSimon Horman <horms@kernel.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    e346e231
qed_dev_api.h 13 KB