[PATCH 4.9 21/28] soc/fsl/qbman: fix issue in qman_delete_cgr_safe()

Greg Kroah-Hartman
2018-03-29T18:00:40Z

From: Madalin Bucur <madalin.bucur@nxp.com>

[ Upstream commit 96f413f47677366e0ae03797409bfcc4151dbf9e ]

The wait_for_completion() call in qman_delete_cgr_safe()
was triggering a scheduling while atomic bug, replacing the
kthread with a smp_call_function_single() call to fix it.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/soc/fsl/qbman/qman.c | 28 +++++-----------------------
1 file changed, 5 insertions(+), 23 deletions(-)

--- a/drivers/soc/fsl/qbman/qman.c
+++ b/drivers/soc/fsl/qbman/qman.c
@@ -2429,39 +2429,21 @@ struct cgr_comp {
struct completion completion;
};

-static int qman_delete_cgr_thread(void *p)
+static void qman_delete_cgr_smp_call(void *p)
{
- struct cgr_comp *cgr_comp = (struct cgr_comp *)p;
- int ret;
-
- ret = qman_delete_cgr(cgr_comp->cgr);
- complete(&cgr_comp->completion);
-
- return ret;
+ qman_delete_cgr((struct qman_cgr *)p);
}

void qman_delete_cgr_safe(struct qman_cgr *cgr)
{
- struct task_struct *thread;
- struct cgr_comp cgr_comp;
-
preempt_disable();
if (qman_cgr_cpus[cgr->cgrid] != smp_processor_id()) {
- init_completion(&cgr_comp.completion);
- cgr_comp.cgr = cgr;
- thread = kthread_create(qman_delete_cgr_thread, &cgr_comp,
- "cgr_del");
-
- if (IS_ERR(thread))
- goto out;
-
- kthread_bind(thread, qman_cgr_cpus[cgr->cgrid]);
- wake_up_process(thread);
- wait_for_completion(&cgr_comp.completion);
+ smp_call_function_single(qman_cgr_cpus[cgr->cgrid],
+ qman_delete_cgr_smp_call, cgr, true);
preempt_enable();
return;
}
-out:
+
qman_delete_cgr(cgr);
preempt_enable();
}