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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/spinlock.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'kernel/spinlock.c')
-rw-r--r--kernel/spinlock.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
new file mode 100644
index 000000000000..e15ed17863f1
--- /dev/null
+++ b/kernel/spinlock.c
@@ -0,0 +1,371 @@
+/*
+ * Copyright (2004) Linus Torvalds
+ *
+ * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
+ *
+ * Copyright (2004) Ingo Molnar
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/preempt.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+
+/*
+ * Generic declaration of the raw read_trylock() function,
+ * architectures are supposed to optimize this:
+ */
+int __lockfunc generic_raw_read_trylock(rwlock_t *lock)
+{
+ _raw_read_lock(lock);
+ return 1;
+}
+EXPORT_SYMBOL(generic_raw_read_trylock);
+
+int __lockfunc _spin_trylock(spinlock_t *lock)
+{
+ preempt_disable();
+ if (_raw_spin_trylock(lock))
+ return 1;
+
+ preempt_enable();
+ return 0;
+}
+EXPORT_SYMBOL(_spin_trylock);
+
+int __lockfunc _read_trylock(rwlock_t *lock)
+{
+ preempt_disable();
+ if (_raw_read_trylock(lock))
+ return 1;
+
+ preempt_enable();
+ return 0;
+}
+EXPORT_SYMBOL(_read_trylock);
+
+int __lockfunc _write_trylock(rwlock_t *lock)
+{
+ preempt_disable();
+ if (_raw_write_trylock(lock))
+ return 1;
+
+ preempt_enable();
+ return 0;
+}
+EXPORT_SYMBOL(_write_trylock);
+
+#ifndef CONFIG_PREEMPT
+
+void __lockfunc _read_lock(rwlock_t *lock)
+{
+ preempt_disable();
+ _raw_read_lock(lock);
+}
+EXPORT_SYMBOL(_read_lock);
+
+unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ preempt_disable();
+ _raw_spin_lock_flags(lock, flags);
+ return flags;
+}
+EXPORT_SYMBOL(_spin_lock_irqsave);
+
+void __lockfunc _spin_lock_irq(spinlock_t *lock)
+{
+ local_irq_disable();
+ preempt_disable();
+ _raw_spin_lock(lock);
+}
+EXPORT_SYMBOL(_spin_lock_irq);
+
+void __lockfunc _spin_lock_bh(spinlock_t *lock)
+{
+ local_bh_disable();
+ preempt_disable();
+ _raw_spin_lock(lock);
+}
+EXPORT_SYMBOL(_spin_lock_bh);
+
+unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ preempt_disable();
+ _raw_read_lock(lock);
+ return flags;
+}
+EXPORT_SYMBOL(_read_lock_irqsave);
+
+void __lockfunc _read_lock_irq(rwlock_t *lock)
+{
+ local_irq_disable();
+ preempt_disable();
+ _raw_read_lock(lock);
+}
+EXPORT_SYMBOL(_read_lock_irq);
+
+void __lockfunc _read_lock_bh(rwlock_t *lock)
+{
+ local_bh_disable();
+ preempt_disable();
+ _raw_read_lock(lock);
+}
+EXPORT_SYMBOL(_read_lock_bh);
+
+unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ preempt_disable();
+ _raw_write_lock(lock);
+ return flags;
+}
+EXPORT_SYMBOL(_write_lock_irqsave);
+
+void __lockfunc _write_lock_irq(rwlock_t *lock)
+{
+ local_irq_disable();
+ preempt_disable();
+ _raw_write_lock(lock);
+}
+EXPORT_SYMBOL(_write_lock_irq);
+
+void __lockfunc _write_lock_bh(rwlock_t *lock)
+{
+ local_bh_disable();
+ preempt_disable();
+ _raw_write_lock(lock);
+}
+EXPORT_SYMBOL(_write_lock_bh);
+
+void __lockfunc _spin_lock(spinlock_t *lock)
+{
+ preempt_disable();
+ _raw_spin_lock(lock);
+}
+
+EXPORT_SYMBOL(_spin_lock);
+
+void __lockfunc _write_lock(rwlock_t *lock)
+{
+ preempt_disable();
+ _raw_write_lock(lock);
+}
+
+EXPORT_SYMBOL(_write_lock);
+
+#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) \
+{ \
+ preempt_disable(); \
+ for (;;) { \
+ 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) \
+ cpu_relax(); \
+ preempt_disable(); \
+ } \
+ (lock)->break_lock = 0; \
+} \
+ \
+EXPORT_SYMBOL(_##op##_lock); \
+ \
+unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
+{ \
+ unsigned long flags; \
+ \
+ preempt_disable(); \
+ for (;;) { \
+ 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) \
+ cpu_relax(); \
+ preempt_disable(); \
+ } \
+ (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 */
+
+void __lockfunc _spin_unlock(spinlock_t *lock)
+{
+ _raw_spin_unlock(lock);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_spin_unlock);
+
+void __lockfunc _write_unlock(rwlock_t *lock)
+{
+ _raw_write_unlock(lock);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_write_unlock);
+
+void __lockfunc _read_unlock(rwlock_t *lock)
+{
+ _raw_read_unlock(lock);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_read_unlock);
+
+void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
+{
+ _raw_spin_unlock(lock);
+ local_irq_restore(flags);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_spin_unlock_irqrestore);
+
+void __lockfunc _spin_unlock_irq(spinlock_t *lock)
+{
+ _raw_spin_unlock(lock);
+ local_irq_enable();
+ preempt_enable();
+}
+EXPORT_SYMBOL(_spin_unlock_irq);
+
+void __lockfunc _spin_unlock_bh(spinlock_t *lock)
+{
+ _raw_spin_unlock(lock);
+ preempt_enable();
+ local_bh_enable();
+}
+EXPORT_SYMBOL(_spin_unlock_bh);
+
+void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
+{
+ _raw_read_unlock(lock);
+ local_irq_restore(flags);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_read_unlock_irqrestore);
+
+void __lockfunc _read_unlock_irq(rwlock_t *lock)
+{
+ _raw_read_unlock(lock);
+ local_irq_enable();
+ preempt_enable();
+}
+EXPORT_SYMBOL(_read_unlock_irq);
+
+void __lockfunc _read_unlock_bh(rwlock_t *lock)
+{
+ _raw_read_unlock(lock);
+ preempt_enable();
+ local_bh_enable();
+}
+EXPORT_SYMBOL(_read_unlock_bh);
+
+void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
+{
+ _raw_write_unlock(lock);
+ local_irq_restore(flags);
+ preempt_enable();
+}
+EXPORT_SYMBOL(_write_unlock_irqrestore);
+
+void __lockfunc _write_unlock_irq(rwlock_t *lock)
+{
+ _raw_write_unlock(lock);
+ local_irq_enable();
+ preempt_enable();
+}
+EXPORT_SYMBOL(_write_unlock_irq);
+
+void __lockfunc _write_unlock_bh(rwlock_t *lock)
+{
+ _raw_write_unlock(lock);
+ preempt_enable();
+ local_bh_enable();
+}
+EXPORT_SYMBOL(_write_unlock_bh);
+
+int __lockfunc _spin_trylock_bh(spinlock_t *lock)
+{
+ local_bh_disable();
+ preempt_disable();
+ if (_raw_spin_trylock(lock))
+ return 1;
+
+ preempt_enable();
+ local_bh_enable();
+ return 0;
+}
+EXPORT_SYMBOL(_spin_trylock_bh);
+
+int in_lock_functions(unsigned long addr)
+{
+ /* Linker adds these: start and end of __lockfunc functions */
+ extern char __lock_text_start[], __lock_text_end[];
+
+ return addr >= (unsigned long)__lock_text_start
+ && addr < (unsigned long)__lock_text_end;
+}
+EXPORT_SYMBOL(in_lock_functions);

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