From: Alexei Starovoitov <ast@xxxxxxxxxx>
Similar to local_lock_irqsave() introduce local_trylock_irqsave().
It uses spin_trylock in PREEMPT_RT and always succeeds when !RT.
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
---
include/linux/local_lock.h | 9 +++++++++
include/linux/local_lock_internal.h | 23 +++++++++++++++++++++++
2 files changed, 32 insertions(+)
diff --git a/include/linux/local_lock.h b/include/linux/local_lock.h
index 091dc0b6bdfb..6880c29b8b98 100644
--- a/include/linux/local_lock.h
+++ b/include/linux/local_lock.h
@@ -30,6 +30,15 @@
#define local_lock_irqsave(lock, flags) \
__local_lock_irqsave(lock, flags)
+/**
+ * local_trylock_irqsave - Try to acquire a per CPU local lock, save and disable
+ * interrupts. Always succeeds in !PREEMPT_RT.
+ * @lock: The lock variable
+ * @flags: Storage for interrupt flags
+ */
+#define local_trylock_irqsave(lock, flags) \
+ __local_trylock_irqsave(lock, flags)
+
/**
* local_unlock - Release a per CPU local lock
* @lock: The lock variable
diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h
index 8dd71fbbb6d2..2c0f8a49c2d0 100644
--- a/include/linux/local_lock_internal.h
+++ b/include/linux/local_lock_internal.h
@@ -31,6 +31,13 @@ static inline void local_lock_acquire(local_lock_t *l)
l->owner = current;
}
+static inline void local_trylock_acquire(local_lock_t *l)
+{
+ lock_map_acquire_try(&l->dep_map);
+ DEBUG_LOCKS_WARN_ON(l->owner);
+ l->owner = current;
+}
+
static inline void local_lock_release(local_lock_t *l)
{
DEBUG_LOCKS_WARN_ON(l->owner != current);
@@ -45,6 +52,7 @@ static inline void local_lock_debug_init(local_lock_t *l)
#else /* CONFIG_DEBUG_LOCK_ALLOC */
# define LOCAL_LOCK_DEBUG_INIT(lockname)
static inline void local_lock_acquire(local_lock_t *l) { }
+static inline void local_trylock_acquire(local_lock_t *l) { }
static inline void local_lock_release(local_lock_t *l) { }
static inline void local_lock_debug_init(local_lock_t *l) { }
#endif /* !CONFIG_DEBUG_LOCK_ALLOC */
@@ -91,6 +99,13 @@ do { \
local_lock_acquire(this_cpu_ptr(lock)); \
} while (0)
+#define __local_trylock_irqsave(lock, flags) \
+ ({ \
+ local_irq_save(flags); \
+ local_trylock_acquire(this_cpu_ptr(lock)); \
+ 1; \
+ })
+
#define __local_unlock(lock) \
do { \
local_lock_release(this_cpu_ptr(lock)); \
@@ -148,6 +163,14 @@ typedef spinlock_t local_lock_t;
__local_lock(lock); \
} while (0)
+#define __local_trylock_irqsave(lock, flags) \
+ ({ \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ migrate_disable(); \
+ spin_trylock(this_cpu_ptr((__lock))); \
+ })
+
#define __local_unlock(__lock) \
do { \
spin_unlock(this_cpu_ptr((__lock))); \
--
2.43.5
