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 01/12] powerpc: qspinlock: Fix qnode->locked value interpretation
Date: Mon, 8 May 2023 12:01:09 +1000 [thread overview]
Message-ID: <20230508020120.218494-2-rmclure@linux.ibm.com> (raw)
In-Reply-To: <20230508020120.218494-1-rmclure@linux.ibm.com>
A comment accompanying the locked attribute of a qnode assigns a value
of 1 to mean that the lock has been acquired. The usages of this
variable however assume opposite semantics. Update usages so that the
assertions of this comment are reflected in this file.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
---
arch/powerpc/lib/qspinlock.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c
index e4bd145255d0..9cf93963772b 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 (node->locked) {
yield_to_preempted(prev_cpu, yield_count);
spin_begin();
return preempted;
@@ -566,7 +566,7 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b
node->lock = lock;
node->cpu = smp_processor_id();
node->yield_cpu = -1;
- node->locked = 0;
+ node->locked = 1;
tail = encode_tail_cpu(node->cpu);
@@ -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 (node->locked) {
spec_barrier();
if (yield_to_prev(lock, node, old, paravirt))
@@ -693,13 +693,13 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b
*/
if (paravirt && pv_prod_head) {
int next_cpu = next->cpu;
- WRITE_ONCE(next->locked, 1);
+ WRITE_ONCE(next->locked, 0);
if (_Q_SPIN_MISO)
asm volatile("miso" ::: "memory");
if (vcpu_is_preempted(next_cpu))
prod_cpu(next_cpu);
} else {
- WRITE_ONCE(next->locked, 1);
+ WRITE_ONCE(next->locked, 0);
if (_Q_SPIN_MISO)
asm volatile("miso" ::: "memory");
}
--
2.37.2
next prev parent reply other threads:[~2023-05-08 2:02 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 ` Rohan McLure [this message]
2023-05-09 2:01 ` [PATCH 01/12] powerpc: qspinlock: Fix qnode->locked value interpretation Nicholas Piggin
2023-05-09 4:26 ` Rohan McLure
2023-05-08 2:01 ` [PATCH 02/12] powerpc: qspinlock: Mark accesses to qnode lock checks Rohan McLure
2023-05-09 2:02 ` 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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