ARC: remove redundant READ_ONCE() in cmpxchg loop

This patch reverts commit 7082a29c22 ("ARC: use ACCESS_ONCE in cmpxchg
loop").

It is not necessary to use READ_ONCE() because cmpxchg contains barrier. We
can get it from commit d57f727264 ("ARC: add compiler barrier to LLSC
based cmpxchg").

Signed-off-by: Bang Li <libang.linuxer@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
This commit is contained in:
Bang Li 2022-03-19 10:03:16 +08:00 committed by Vineet Gupta
parent ac411e41ec
commit c6ed4d84a2

View File

@ -274,7 +274,7 @@ static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg)
* and read back old value
*/
do {
new = old = READ_ONCE(*ipi_data_ptr);
new = old = *ipi_data_ptr;
new |= 1U << msg;
} while (cmpxchg(ipi_data_ptr, old, new) != old);