From 051790eecc03aff6978763791d38c1daea94c2f8 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 15 Aug 2021 23:28:22 +0200 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210815211303.654230709@linutronix.de --- 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 42be1116e051..8a9aadbaf293 100644 --- a/include/linux/spinlock_types.h +++ b/include/linux/spinlock_types.h @@ -11,6 +11,9 @@ #include +#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 + +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 #endif /* __LINUX_SPINLOCK_TYPES_H */