The following commit has been merged into the locking/core branch of tip:
Commit-ID: 051790eecc03aff6978763791d38c1daea94c2f8
Gitweb: https://git.kernel.org/tip/051790eecc03aff6978763791d38c1daea94c2f8
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sun, 15 Aug 2021 23:28:22 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 17 Aug 2021 17:41:24 +02:00
locking/spinlock: Provide RT specific spinlock_t
RT replaces spinlocks with a simple wrapper around an rtmutex, which turns
spinlocks on RT into 'sleeping' spinlocks. The actual implementation of the
spinlock API differs from a regular rtmutex, as it does neither handle
timeouts nor signals and it is state preserving across the lock operation.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210815211303.654230709@xxxxxxxxxxxxx
---
include/linux/spinlock_types.h | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 42be111..8a9aadb 100644
--- a/include/linux/spinlock_types.h
+++ b/include/linux/spinlock_types.h
@@ -11,6 +11,9 @@
#include <linux/spinlock_types_raw.h>
+#ifndef CONFIG_PREEMPT_RT
+
+/* Non PREEMPT_RT kernels map spinlock to raw_spinlock */
typedef struct spinlock {
union {
struct raw_spinlock rlock;
@@ -39,6 +42,29 @@ typedef struct spinlock {
#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+#else /* !CONFIG_PREEMPT_RT */
+
+/* PREEMPT_RT kernels map spinlock to rt_mutex */
+#include <linux/rtmutex.h>
+
+typedef struct spinlock {
+ struct rt_mutex_base lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} spinlock_t;
+
+#define __SPIN_LOCK_UNLOCKED(name) \
+ { \
+ .lock = __RT_MUTEX_BASE_INITIALIZER(name.lock), \
+ SPIN_DEP_MAP_INIT(name) \
+ }
+
+#define DEFINE_SPINLOCK(name) \
+ spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#endif /* CONFIG_PREEMPT_RT */
+
#include <linux/rwlock_types.h>
#endif /* __LINUX_SPINLOCK_TYPES_H */
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