[PATCH v4 1/5] locking/qspinlock: Rename arch_mcs_spin_unlock_contended to arch_mcs_pass_lock and make it more generic

From: Alex Kogan
Date: Fri Sep 06 2019 - 10:35:17 EST


The new macro should accept the value to be stored into the lock argument
as another argument. This allows using the same macro in cases where the
value to be stored when passing the lock is different from 1.

Signed-off-by: Alex Kogan <alex.kogan@xxxxxxxxxx>
Reviewed-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
---
arch/arm/include/asm/mcs_spinlock.h | 4 ++--
kernel/locking/mcs_spinlock.h | 6 +++---
kernel/locking/qspinlock.c | 2 +-
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/mcs_spinlock.h b/arch/arm/include/asm/mcs_spinlock.h
index 529d2cf4d06f..f3f9efdcd2ca 100644
--- a/arch/arm/include/asm/mcs_spinlock.h
+++ b/arch/arm/include/asm/mcs_spinlock.h
@@ -14,9 +14,9 @@ do { \
wfe(); \
} while (0) \

-#define arch_mcs_spin_unlock_contended(lock) \
+#define arch_mcs_pass_lock(lock, val) \
do { \
- smp_store_release(lock, 1); \
+ smp_store_release((lock), (val)); \
dsb_sev(); \
} while (0)

diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index 5e10153b4d3c..84327ca21650 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/kernel/locking/mcs_spinlock.h
@@ -41,8 +41,8 @@ do { \
* operations in the critical section has been completed before
* unlocking.
*/
-#define arch_mcs_spin_unlock_contended(l) \
- smp_store_release((l), 1)
+#define arch_mcs_pass_lock(l, val) \
+ smp_store_release((l), (val))
#endif

/*
@@ -115,7 +115,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
}

/* Pass lock to next waiter. */
- arch_mcs_spin_unlock_contended(&next->locked);
+ arch_mcs_pass_lock(&next->locked, 1);
}

#endif /* __LINUX_MCS_SPINLOCK_H */
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 2473f10c6956..c3dfcb689400 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -549,7 +549,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
if (!next)
next = smp_cond_load_relaxed(&node->next, (VAL));

- arch_mcs_spin_unlock_contended(&next->locked);
+ arch_mcs_pass_lock(&next->locked, 1);
pv_kick_node(lock, next);

release:
--
2.11.0 (Apple Git-81)