crypto: hisilicon/qm - prevent soft lockup in receive loop
authorLongfang Liu <liulongfang@huawei.com>
Fri, 20 Oct 2023 09:35:58 +0000 (17:35 +0800)
committerHerbert Xu <herbert@gondor.apana.org.au>
Fri, 27 Oct 2023 10:04:27 +0000 (18:04 +0800)
commit33fc506d2ac514be1072499a263c3bff8c7c95a0
treefad7ce5bfb4e50c2b6ff2e8512773816b57f752d
parentbc456c7e24a2f3645117621926178c7ed20040e7
crypto: hisilicon/qm - prevent soft lockup in receive loop

In the scenario where the accelerator business is fully loaded.
When the workqueue receiving messages and performing callback
processing, there are a large number of messages that need to be
received, and there are continuously messages that have been
processed and need to be received.
This will cause the receive loop here to be locked for a long time.
This scenario will cause watchdog timeout problems on OS with kernel
preemption turned off.

The error logs:
watchdog: BUG: soft lockup - CPU#23 stuck for 23s! [kworker/u262:1:1407]
[ 1461.978428][   C23] Call trace:
[ 1461.981890][   C23]  complete+0x8c/0xf0
[ 1461.986031][   C23]  kcryptd_async_done+0x154/0x1f4 [dm_crypt]
[ 1461.992154][   C23]  sec_skcipher_callback+0x7c/0xf4 [hisi_sec2]
[ 1461.998446][   C23]  sec_req_cb+0x104/0x1f4 [hisi_sec2]
[ 1462.003950][   C23]  qm_poll_req_cb+0xcc/0x150 [hisi_qm]
[ 1462.009531][   C23]  qm_work_process+0x60/0xc0 [hisi_qm]
[ 1462.015101][   C23]  process_one_work+0x1c4/0x470
[ 1462.020052][   C23]  worker_thread+0x150/0x3c4
[ 1462.024735][   C23]  kthread+0x108/0x13c
[ 1462.028889][   C23]  ret_from_fork+0x10/0x18

Therefore, it is necessary to add an actively scheduled operation in the
while loop to prevent this problem.
After adding it, no matter whether the OS turns on or off the kernel
preemption function. Neither will cause watchdog timeout issues.

Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
drivers/crypto/hisilicon/qm.c