locking: Implement new raw_spinlock

Now that the raw_spin name space is freed up, we can implement
raw_spinlock and the related functions which are used to annotate the
locks which are not converted to sleeping spinlocks in preempt-rt.

A side effect is that only such locks can be used with the low level
lock fsunctions which circumvent lockdep.

For !rt spin_* functions are mapped to the raw_spin* implementations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 194 insertions, 64 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 53bc2213b414..ef5a55d96b9b 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -80,7 +80,7 @@
 #include <linux/spinlock_types.h>
 
 /*
- * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
+ * Pull the arch_spin*() functions/declarations (UP-nondebug doesnt need them):
  */
 #ifdef CONFIG_SMP
 # include <asm/spinlock.h>
@@ -89,30 +89,30 @@
 #endif
 
 #ifdef CONFIG_DEBUG_SPINLOCK
-  extern void __spin_lock_init(spinlock_t *lock, const char *name,
-                               struct lock_class_key *key);
-# define spin_lock_init(lock)                                   \
+  extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
+                                   struct lock_class_key *key);
+# define raw_spin_lock_init(lock)                               \
 do {                                                            \
         static struct lock_class_key __key;                     \
                                                                 \
-        __spin_lock_init((lock), #lock, &__key);                \
+        __raw_spin_lock_init((lock), #lock, &__key);            \
 } while (0)
 
 #else
-# define spin_lock_init(lock)                                   \
-        do { *(lock) = __SPIN_LOCK_UNLOCKED(lock); } while (0)
+# define raw_spin_lock_init(lock)                               \
+        do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
 #endif
 
-#define spin_is_locked(lock)    arch_spin_is_locked(&(lock)->raw_lock)
+#define raw_spin_is_locked(lock)        arch_spin_is_locked(&(lock)->raw_lock)
 
 #ifdef CONFIG_GENERIC_LOCKBREAK
-#define spin_is_contended(lock) ((lock)->break_lock)
+#define raw_spin_is_contended(lock) ((lock)->break_lock)
 #else
 
 #ifdef arch_spin_is_contended
-#define spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
+#define raw_spin_is_contended(lock)     arch_spin_is_contended(&(lock)->raw_lock)
 #else
-#define spin_is_contended(lock) (((void)(lock), 0))
+#define raw_spin_is_contended(lock)     (((void)(lock), 0))
 #endif /*arch_spin_is_contended*/
 #endif
 
@@ -122,22 +122,37 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
 #endif
 
 /**
- * spin_unlock_wait - wait until the spinlock gets unlocked
+ * raw_spin_unlock_wait - wait until the spinlock gets unlocked
  * @lock: the spinlock in question.
  */
-#define spin_unlock_wait(lock)  arch_spin_unlock_wait(&(lock)->raw_lock)
+#define raw_spin_unlock_wait(lock)      arch_spin_unlock_wait(&(lock)->raw_lock)
 
 #ifdef CONFIG_DEBUG_SPINLOCK
- extern void _raw_spin_lock(spinlock_t *lock);
+ extern void _raw_spin_lock(raw_spinlock_t *lock);
 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
- extern int _raw_spin_trylock(spinlock_t *lock);
- extern void _raw_spin_unlock(spinlock_t *lock);
+ extern int _raw_spin_trylock(raw_spinlock_t *lock);
+ extern void _raw_spin_unlock(raw_spinlock_t *lock);
 #else
-# define _raw_spin_lock(lock)           arch_spin_lock(&(lock)->raw_lock)
-# define _raw_spin_lock_flags(lock, flags) \
-                arch_spin_lock_flags(&(lock)->raw_lock, *(flags))
-# define _raw_spin_trylock(lock)        arch_spin_trylock(&(lock)->raw_lock)
-# define _raw_spin_unlock(lock)         arch_spin_unlock(&(lock)->raw_lock)
+static inline void _raw_spin_lock(raw_spinlock_t *lock)
+{
+        arch_spin_lock(&lock->raw_lock);
+}
+
+static inline void
+_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags)
+{
+        arch_spin_lock_flags(&lock->raw_lock, *flags);
+}
+
+static inline int _raw_spin_trylock(raw_spinlock_t *lock)
+{
+        return arch_spin_trylock(&(lock)->raw_lock);
+}
+
+static inline void _raw_spin_unlock(raw_spinlock_t *lock)
+{
+        arch_spin_unlock(&lock->raw_lock);
+}
 #endif
 
 /*
@@ -146,38 +161,38 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
  * various methods are defined as nops in the case they are not
  * required.
  */
-#define spin_trylock(lock)              __cond_lock(lock, _spin_trylock(lock))
+#define raw_spin_trylock(lock)          __cond_lock(lock, _spin_trylock(lock))
 
-#define spin_lock(lock)                 _spin_lock(lock)
+#define raw_spin_lock(lock)             _spin_lock(lock)
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
-# define spin_lock_nest_lock(lock, nest_lock)                           \
+# define raw_spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
+# define raw_spin_lock_nest_lock(lock, nest_lock)                       \
          do {                                                           \
                  typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
                  _spin_lock_nest_lock(lock, &(nest_lock)->dep_map);     \
          } while (0)
 #else
-# define spin_lock_nested(lock, subclass) _spin_lock(lock)
-# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
+# define raw_spin_lock_nested(lock, subclass)           _spin_lock(lock)
+# define raw_spin_lock_nest_lock(lock, nest_lock)       _spin_lock(lock)
 #endif
 
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 
-#define spin_lock_irqsave(lock, flags)                  \
+#define raw_spin_lock_irqsave(lock, flags)                      \
         do {                                            \
                 typecheck(unsigned long, flags);        \
                 flags = _spin_lock_irqsave(lock);       \
         } while (0)
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-#define spin_lock_irqsave_nested(lock, flags, subclass)                 \
+#define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
         do {                                                            \
                 typecheck(unsigned long, flags);                        \
                 flags = _spin_lock_irqsave_nested(lock, subclass);      \
         } while (0)
 #else
-#define spin_lock_irqsave_nested(lock, flags, subclass)                 \
+#define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
         do {                                                            \
                 typecheck(unsigned long, flags);                        \
                 flags = _spin_lock_irqsave(lock);                       \
@@ -186,45 +201,178 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
 
 #else
 
-#define spin_lock_irqsave(lock, flags)                  \
+#define raw_spin_lock_irqsave(lock, flags)              \
         do {                                            \
                 typecheck(unsigned long, flags);        \
                 _spin_lock_irqsave(lock, flags);        \
         } while (0)
 
-#define spin_lock_irqsave_nested(lock, flags, subclass) \
-        spin_lock_irqsave(lock, flags)
+#define raw_spin_lock_irqsave_nested(lock, flags, subclass)     \
+        raw_spin_lock_irqsave(lock, flags)
 
 #endif
 
-#define spin_lock_irq(lock)             _spin_lock_irq(lock)
-#define spin_lock_bh(lock)              _spin_lock_bh(lock)
-#define spin_unlock(lock)               _spin_unlock(lock)
-#define spin_unlock_irq(lock)           _spin_unlock_irq(lock)
+#define raw_spin_lock_irq(lock) _spin_lock_irq(lock)
+#define raw_spin_lock_bh(lock)          _spin_lock_bh(lock)
+#define raw_spin_unlock(lock)           _spin_unlock(lock)
+#define raw_spin_unlock_irq(lock)       _spin_unlock_irq(lock)
 
-#define spin_unlock_irqrestore(lock, flags)             \
-        do {                                            \
-                typecheck(unsigned long, flags);        \
+#define raw_spin_unlock_irqrestore(lock, flags)         \
+        do {                                                    \
+                typecheck(unsigned long, flags);                \
                 _spin_unlock_irqrestore(lock, flags);   \
         } while (0)
-#define spin_unlock_bh(lock)            _spin_unlock_bh(lock)
+#define raw_spin_unlock_bh(lock)        _spin_unlock_bh(lock)
 
-#define spin_trylock_bh(lock)   __cond_lock(lock, _spin_trylock_bh(lock))
+#define raw_spin_trylock_bh(lock)       __cond_lock(lock, _spin_trylock_bh(lock))
 
-#define spin_trylock_irq(lock) \
+#define raw_spin_trylock_irq(lock) \
 ({ \
         local_irq_disable(); \
-        spin_trylock(lock) ? \
+        raw_spin_trylock(lock) ? \
         1 : ({ local_irq_enable(); 0;  }); \
 })
 
-#define spin_trylock_irqsave(lock, flags) \
+#define raw_spin_trylock_irqsave(lock, flags) \
 ({ \
         local_irq_save(flags); \
-        spin_trylock(lock) ? \
+        raw_spin_trylock(lock) ? \
         1 : ({ local_irq_restore(flags); 0; }); \
 })
 
+/**
+ * raw_spin_can_lock - would raw_spin_trylock() succeed?
+ * @lock: the spinlock in question.
+ */
+#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
+
+/* Include rwlock functions */
+#include <linux/rwlock.h>
+
+/*
+ * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+# include <linux/spinlock_api_smp.h>
+#else
+# include <linux/spinlock_api_up.h>
+#endif
+
+/*
+ * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
+ */
+
+static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
+{
+        return &lock->rlock;
+}
+
+#define spin_lock_init(_lock)                           \
+do {                                                    \
+        spinlock_check(_lock);                          \
+        raw_spin_lock_init(&(_lock)->rlock);            \
+} while (0)
+
+static inline void spin_lock(spinlock_t *lock)
+{
+        raw_spin_lock(&lock->rlock);
+}
+
+static inline void spin_lock_bh(spinlock_t *lock)
+{
+        raw_spin_lock_bh(&lock->rlock);
+}
+
+static inline int spin_trylock(spinlock_t *lock)
+{
+        return raw_spin_trylock(&lock->rlock);
+}
+
+#define spin_lock_nested(lock, subclass)                        \
+do {                                                            \
+        raw_spin_lock_nested(spinlock_check(lock), subclass);   \
+} while (0)
+
+#define spin_lock_nest_lock(lock, nest_lock)                            \
+do {                                                                    \
+        raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);       \
+} while (0)
+
+static inline void spin_lock_irq(spinlock_t *lock)
+{
+        raw_spin_lock_irq(&lock->rlock);
+}
+
+#define spin_lock_irqsave(lock, flags)                          \
+do {                                                            \
+        raw_spin_lock_irqsave(spinlock_check(lock), flags);     \
+} while (0)
+
+#define spin_lock_irqsave_nested(lock, flags, subclass)                 \
+do {                                                                    \
+        raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
+} while (0)
+
+static inline void spin_unlock(spinlock_t *lock)
+{
+        raw_spin_unlock(&lock->rlock);
+}
+
+static inline void spin_unlock_bh(spinlock_t *lock)
+{
+        raw_spin_unlock_bh(&lock->rlock);
+}
+
+static inline void spin_unlock_irq(spinlock_t *lock)
+{
+        raw_spin_unlock_irq(&lock->rlock);
+}
+
+static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
+{
+        raw_spin_unlock_irqrestore(&lock->rlock, flags);
+}
+
+static inline int spin_trylock_bh(spinlock_t *lock)
+{
+        return raw_spin_trylock_bh(&lock->rlock);
+}
+
+static inline int spin_trylock_irq(spinlock_t *lock)
+{
+        return raw_spin_trylock_irq(&lock->rlock);
+}
+
+#define spin_trylock_irqsave(lock, flags)                       \
+({                                                              \
+        raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
+})
+
+static inline void spin_unlock_wait(spinlock_t *lock)
+{
+        raw_spin_unlock_wait(&lock->rlock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+        return raw_spin_is_locked(&lock->rlock);
+}
+
+static inline int spin_is_contended(spinlock_t *lock)
+{
+        return raw_spin_is_contended(&lock->rlock);
+}
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+        return raw_spin_can_lock(&lock->rlock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+        assert_raw_spin_locked(&lock->rlock);
+}
+
 /*
  * Pull the atomic_t declaration:
  * (asm-mips/atomic.h needs above definitions)
@@ -242,22 +390,4 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
 #define atomic_dec_and_lock(atomic, lock) \
                 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
 
-/**
- * spin_can_lock - would spin_trylock() succeed?
- * @lock: the spinlock in question.
- */
-#define spin_can_lock(lock)     (!spin_is_locked(lock))
-
-/* Include rwlock functions */
-#include <linux/rwlock.h>
-
-/*
- * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-# include <linux/spinlock_api_smp.h>
-#else
-# include <linux/spinlock_api_up.h>
-#endif
-
 #endif /* __LINUX_SPINLOCK_H */