locking: Reduce ifdefs in kernel/spinlock.c
authorThomas Gleixner <tglx@linutronix.de>
Mon, 9 Nov 2009 15:21:41 +0000 (15:21 +0000)
committerThomas Gleixner <tglx@linutronix.de>
Fri, 13 Nov 2009 19:53:28 +0000 (20:53 +0100)
With the Kconfig based inline decisions we can remove extra ifdefs in
kernel/spinlock.c by creating the complex lockbreak functions as
inlines which are inserted into the non inlined lock functions.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091109151428.548614772@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
kernel/spinlock.c

index 235a957..41e0422 100644 (file)
 #include <linux/debug_locks.h>
 #include <linux/module.h>
 
+/*
+ * If lockdep is enabled then we use the non-preemption spin-ops
+ * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
+ * not re-enabled during lock-acquire (which the preempt-spin-ops do):
+ */
+#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
+/*
+ * The __lock_function inlines are taken from
+ * include/linux/spinlock_api_smp.h
+ */
+#else
+/*
+ * We build the __lock_function inlines here. They are too large for
+ * inlining all over the place, but here is only one user per function
+ * which embedds them into the calling _lock_function below.
+ *
+ * This could be a long-held lock. We both prepare to spin for a long
+ * time (making _this_ CPU preemptable if possible), and we also signal
+ * towards that other CPU that it should break the lock ASAP.
+ */
+#define BUILD_LOCK_OPS(op, locktype)                                   \
+void __lockfunc __##op##_lock(locktype##_t *lock)                      \
+{                                                                      \
+       for (;;) {                                                      \
+               preempt_disable();                                      \
+               if (likely(_raw_##op##_trylock(lock)))                  \
+                       break;                                          \
+               preempt_enable();                                       \
+                                                                       \
+               if (!(lock)->break_lock)                                \
+                       (lock)->break_lock = 1;                         \
+               while (!op##_can_lock(lock) && (lock)->break_lock)      \
+                       _raw_##op##_relax(&lock->raw_lock);             \
+       }                                                               \
+       (lock)->break_lock = 0;                                         \
+}                                                                      \
+                                                                       \
+unsigned long __lockfunc __##op##_lock_irqsave(locktype##_t *lock)     \
+{                                                                      \
+       unsigned long flags;                                            \
+                                                                       \
+       for (;;) {                                                      \
+               preempt_disable();                                      \
+               local_irq_save(flags);                                  \
+               if (likely(_raw_##op##_trylock(lock)))                  \
+                       break;                                          \
+               local_irq_restore(flags);                               \
+               preempt_enable();                                       \
+                                                                       \
+               if (!(lock)->break_lock)                                \
+                       (lock)->break_lock = 1;                         \
+               while (!op##_can_lock(lock) && (lock)->break_lock)      \
+                       _raw_##op##_relax(&lock->raw_lock);             \
+       }                                                               \
+       (lock)->break_lock = 0;                                         \
+       return flags;                                                   \
+}                                                                      \
+                                                                       \
+void __lockfunc __##op##_lock_irq(locktype##_t *lock)                  \
+{                                                                      \
+       _##op##_lock_irqsave(lock);                                     \
+}                                                                      \
+                                                                       \
+void __lockfunc __##op##_lock_bh(locktype##_t *lock)                   \
+{                                                                      \
+       unsigned long flags;                                            \
+                                                                       \
+       /*                                                      */      \
+       /* Careful: we must exclude softirqs too, hence the     */      \
+       /* irq-disabling. We use the generic preemption-aware   */      \
+       /* function:                                            */      \
+       /**/                                                            \
+       flags = _##op##_lock_irqsave(lock);                             \
+       local_bh_disable();                                             \
+       local_irq_restore(flags);                                       \
+}                                                                      \
+
+/*
+ * Build preemption-friendly versions of the following
+ * lock-spinning functions:
+ *
+ *         __[spin|read|write]_lock()
+ *         __[spin|read|write]_lock_irq()
+ *         __[spin|read|write]_lock_irqsave()
+ *         __[spin|read|write]_lock_bh()
+ */
+BUILD_LOCK_OPS(spin, spinlock);
+BUILD_LOCK_OPS(read, rwlock);
+BUILD_LOCK_OPS(write, rwlock);
+
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
+{
+       preempt_disable();
+       spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+       LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+EXPORT_SYMBOL(_spin_lock_nested);
+
+unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock,
+                                                  int subclass)
+{
+       unsigned long flags;
+
+       local_irq_save(flags);
+       preempt_disable();
+       spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+       LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
+                               _raw_spin_lock_flags, &flags);
+       return flags;
+}
+EXPORT_SYMBOL(_spin_lock_irqsave_nested);
+
+void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
+                                    struct lockdep_map *nest_lock)
+{
+       preempt_disable();
+       spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
+       LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+EXPORT_SYMBOL(_spin_lock_nest_lock);
+
+#endif
+
 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
 int __lockfunc _spin_trylock(spinlock_t *lock)
 {
@@ -45,13 +172,6 @@ int __lockfunc _write_trylock(rwlock_t *lock)
 EXPORT_SYMBOL(_write_trylock);
 #endif
 
-/*
- * If lockdep is enabled then we use the non-preemption spin-ops
- * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
- * not re-enabled during lock-acquire (which the preempt-spin-ops do):
- */
-#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
-
 #ifndef CONFIG_INLINE_READ_LOCK
 void __lockfunc _read_lock(rwlock_t *lock)
 {
@@ -148,130 +268,6 @@ void __lockfunc _write_lock(rwlock_t *lock)
 EXPORT_SYMBOL(_write_lock);
 #endif
 
-#else /* CONFIG_PREEMPT: */
-
-/*
- * This could be a long-held lock. We both prepare to spin for a long
- * time (making _this_ CPU preemptable if possible), and we also signal
- * towards that other CPU that it should break the lock ASAP.
- *
- * (We do this in a function because inlining it would be excessive.)
- */
-
-#define BUILD_LOCK_OPS(op, locktype)                                   \
-void __lockfunc _##op##_lock(locktype##_t *lock)                       \
-{                                                                      \
-       for (;;) {                                                      \
-               preempt_disable();                                      \
-               if (likely(_raw_##op##_trylock(lock)))                  \
-                       break;                                          \
-               preempt_enable();                                       \
-                                                                       \
-               if (!(lock)->break_lock)                                \
-                       (lock)->break_lock = 1;                         \
-               while (!op##_can_lock(lock) && (lock)->break_lock)      \
-                       _raw_##op##_relax(&lock->raw_lock);             \
-       }                                                               \
-       (lock)->break_lock = 0;                                         \
-}                                                                      \
-                                                                       \
-EXPORT_SYMBOL(_##op##_lock);                                           \
-                                                                       \
-unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock)      \
-{                                                                      \
-       unsigned long flags;                                            \
-                                                                       \
-       for (;;) {                                                      \
-               preempt_disable();                                      \
-               local_irq_save(flags);                                  \
-               if (likely(_raw_##op##_trylock(lock)))                  \
-                       break;                                          \
-               local_irq_restore(flags);                               \
-               preempt_enable();                                       \
-                                                                       \
-               if (!(lock)->break_lock)                                \
-                       (lock)->break_lock = 1;                         \
-               while (!op##_can_lock(lock) && (lock)->break_lock)      \
-                       _raw_##op##_relax(&lock->raw_lock);             \
-       }                                                               \
-       (lock)->break_lock = 0;                                         \
-       return flags;                                                   \
-}                                                                      \
-                                                                       \
-EXPORT_SYMBOL(_##op##_lock_irqsave);                                   \
-                                                                       \
-void __lockfunc _##op##_lock_irq(locktype##_t *lock)                   \
-{                                                                      \
-       _##op##_lock_irqsave(lock);                                     \
-}                                                                      \
-                                                                       \
-EXPORT_SYMBOL(_##op##_lock_irq);                                       \
-                                                                       \
-void __lockfunc _##op##_lock_bh(locktype##_t *lock)                    \
-{                                                                      \
-       unsigned long flags;                                            \
-                                                                       \
-       /*                                                      */      \
-       /* Careful: we must exclude softirqs too, hence the     */      \
-       /* irq-disabling. We use the generic preemption-aware   */      \
-       /* function:                                            */      \
-       /**/                                                            \
-       flags = _##op##_lock_irqsave(lock);                             \
-       local_bh_disable();                                             \
-       local_irq_restore(flags);                                       \
-}                                                                      \
-                                                                       \
-EXPORT_SYMBOL(_##op##_lock_bh)
-
-/*
- * Build preemption-friendly versions of the following
- * lock-spinning functions:
- *
- *         _[spin|read|write]_lock()
- *         _[spin|read|write]_lock_irq()
- *         _[spin|read|write]_lock_irqsave()
- *         _[spin|read|write]_lock_bh()
- */
-BUILD_LOCK_OPS(spin, spinlock);
-BUILD_LOCK_OPS(read, rwlock);
-BUILD_LOCK_OPS(write, rwlock);
-
-#endif /* CONFIG_PREEMPT */
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-
-void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
-{
-       preempt_disable();
-       spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
-       LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
-}
-EXPORT_SYMBOL(_spin_lock_nested);
-
-unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
-{
-       unsigned long flags;
-
-       local_irq_save(flags);
-       preempt_disable();
-       spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
-       LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
-                               _raw_spin_lock_flags, &flags);
-       return flags;
-}
-EXPORT_SYMBOL(_spin_lock_irqsave_nested);
-
-void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
-                                    struct lockdep_map *nest_lock)
-{
-       preempt_disable();
-       spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
-       LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
-}
-EXPORT_SYMBOL(_spin_lock_nest_lock);
-
-#endif
-
 #ifndef CONFIG_INLINE_SPIN_UNLOCK
 void __lockfunc _spin_unlock(spinlock_t *lock)
 {