[PATCH 03/12] powerpc: qspinlock: Enforce qnode writes prior to publishing to queue
From: Rohan McLure <hidden>
Date: 2023-05-08 02:04:27
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Use a compiler barrier to enforce that all fields of a new struct qnode be written to (especially the lock value) before publishing the qnode to the waitqueue. Signed-off-by: Rohan McLure <redacted> --- arch/powerpc/lib/qspinlock.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c
index 579290d55abf..d548001a86be 100644
--- a/arch/powerpc/lib/qspinlock.c
+++ b/arch/powerpc/lib/qspinlock.c@@ -567,6 +567,10 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b node->cpu = smp_processor_id(); node->yield_cpu = -1; node->locked = 1; + /* + * Assign all attributes of a node before it can be published. + */ + barrier(); tail = encode_tail_cpu(node->cpu);
--
2.37.2