From: Rohan McLure <rmclure@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Rohan McLure <rmclure@linux.ibm.com>, npiggin@gmail.com, arnd@arndb.de
Subject: [PATCH 02/12] powerpc: qspinlock: Mark accesses to qnode lock checks
Date: Mon, 8 May 2023 12:01:10 +1000 [thread overview]
Message-ID: <20230508020120.218494-3-rmclure@linux.ibm.com> (raw)
In-Reply-To: <20230508020120.218494-1-rmclure@linux.ibm.com>
The powerpc implemenation of qspinlocks will both poll and spin on the
bitlock guarding a qnode. Mark these accesses with READ_ONCE to convey
to KCSAN that polling is intentional here.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
---
arch/powerpc/lib/qspinlock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c
index 9cf93963772b..579290d55abf 100644
--- a/arch/powerpc/lib/qspinlock.c
+++ b/arch/powerpc/lib/qspinlock.c
@@ -435,7 +435,7 @@ static __always_inline bool yield_to_prev(struct qspinlock *lock, struct qnode *
smp_rmb(); /* See __yield_to_locked_owner comment */
- if (node->locked) {
+ if (READ_ONCE(node->locked)) {
yield_to_preempted(prev_cpu, yield_count);
spin_begin();
return preempted;
@@ -584,7 +584,7 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b
/* Wait for mcs node lock to be released */
spin_begin();
- while (node->locked) {
+ while (READ_ONCE(node->locked)) {
spec_barrier();
if (yield_to_prev(lock, node, old, paravirt))
--
2.37.2
next prev parent reply other threads:[~2023-05-08 2:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-08 2:01 [PATCH 00/12] powerpc: KCSAN fix warnings and mark accesses Rohan McLure
2023-05-08 2:01 ` [PATCH 01/12] powerpc: qspinlock: Fix qnode->locked value interpretation Rohan McLure
2023-05-09 2:01 ` Nicholas Piggin
2023-05-09 4:26 ` Rohan McLure
2023-05-08 2:01 ` Rohan McLure [this message]
2023-05-09 2:02 ` [PATCH 02/12] powerpc: qspinlock: Mark accesses to qnode lock checks Nicholas Piggin
2023-05-08 2:01 ` [PATCH 03/12] powerpc: qspinlock: Enforce qnode writes prior to publishing to queue Rohan McLure
2023-05-09 2:04 ` Nicholas Piggin
2023-05-09 5:26 ` Rohan McLure
2023-05-09 6:45 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 04/12] asm-generic/mmiowb: Mark accesses to fix KCSAN warnings Rohan McLure
2023-05-08 6:30 ` Arnd Bergmann
2023-05-08 15:44 ` [PATCH 4/12] " Gautam Menghani
2023-05-09 2:16 ` [PATCH 04/12] " Nicholas Piggin
2023-05-08 2:01 ` [PATCH 05/12] powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid Rohan McLure
2023-05-09 2:17 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 06/12] powerpc: Mark accesses to power_save callback in arch_cpu_idle Rohan McLure
2023-05-09 2:21 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 07/12] powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention Rohan McLure
2023-05-09 2:26 ` Nicholas Piggin
2023-05-10 2:00 ` Rohan McLure
2023-05-08 2:01 ` [PATCH 08/12] powerpc: Annotate accesses to ipi message flags Rohan McLure
2023-05-09 2:28 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 09/12] powerpc: Mark writes registering ipi to host cpu through kvm Rohan McLure
2023-05-09 2:30 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 10/12] powerpc: powernv: Annotate data races in opal events Rohan McLure
2023-05-09 2:31 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 11/12] powerpc: powernv: Annotate asynchronous access to opal tokens Rohan McLure
2023-05-08 2:01 ` [PATCH 12/12] powerpc: Mark asynchronous accesses to irq_data Rohan McLure
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