[PATCH v3 06/11] smp: use smp_call_csd() from irq_work.c and core.c

Donghai Qiao
2022-05-17T18:04:24Z

irq_work.c and core.c should use the cross interface rather than
using a unpublished internal function __smp_call_single_queue.

But this change also exposed unpublished types SMP_CALL_TYPE_TTWU and
SMP_CALL_TYPE_IRQ_WORK. However, this is a temporarily change so that
all kernel clients can call the interface as the first step. A
permanent solution should implement new cross call func() for both
and from there the TTWU and IRQ_WORK types of requests can be processed.
That way, the special TTWU and IRQ_WORK types will not be visible from
the cross call interface. Because this needs to change core.s and
irq_work.c, this should be done with a follow up patch set to reduce
the level of risk.

Signed-off-by: Donghai Qiao <dqiao@redhat.com>
---
v1 -> v2: Removed 'x' from the function names and change XCALL to
SMP_CALL from the new macros
v2 -> v3: Modifed the commit comments
kernel/irq_work.c | 4 ++--
kernel/sched/core.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 7afa40fe5cc4..aa67ea2ccb8f 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -159,8 +159,8 @@ bool irq_work_queue_on(struct irq_work *work, int cpu)
if (!irq_work_claim(work))
goto out;
}
-
- __smp_call_single_queue(cpu, &work->node.llist);
+ smp_call_csd(cpu, (call_single_data_t *)&work->node.llist,
+ SMP_CALL_TYPE_IRQ_WORK);
} else {
__irq_work_queue_local(work);
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 51efaabac3e4..6d1d30bd6220 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3780,7 +3780,7 @@ static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags
p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);

WRITE_ONCE(rq->ttwu_pending, 1);
- __smp_call_single_queue(cpu, &p->wake_entry.llist);
+ smp_call_csd(cpu, (call_single_data_t *)&p->wake_entry.llist, SMP_CALL_TYPE_TTWU);
}

void wake_up_if_idle(int cpu)
--
2.27.0