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linux/kernel/spinlock.c
Thomas Gleixner 6beb000923 locking: Make inlining decision Kconfig based 
commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the
selection of which lock functions are inlined based on defines in
arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION

Despite of the name __always_inline__* the lock functions can be built
out of line depending on config options. Also if the arch does not set
some inline defines the generic code might set them; again depending on
config options.

This makes it unnecessary hard to figure out when and which lock
functions are inlined. Aside of that it makes it way harder and
messier for -rt to manipulate the lock functions.

Convert the inlining decision to CONFIG switches. Each lock function
is inlined depending on CONFIG_INLINE_*. The configs implement the
existing dependencies. The architecture code can select ARCH_INLINE_*
to signal that it wants the corresponding lock function inlined.
ARCH_INLINE_* is necessary as Kconfig ignores "depends on"
restrictions when a config element is selected.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091109151428.504477141@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>
2009-11-13 20:53:28 +01:00

388 lines
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/*
* Copyright (2004) Linus Torvalds
*
* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
*
* Copyright (2004, 2005) Ingo Molnar
*
* This file contains the spinlock/rwlock implementations for the
* SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
*
* Note that some architectures have special knowledge about the
* stack frames of these functions in their profile_pc. If you
* change anything significant here that could change the stack
* frame contact the architecture maintainers.
*/
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/module.h>
#ifndef CONFIG_INLINE_SPIN_TRYLOCK
int __lockfunc _spin_trylock(spinlock_t *lock)
{
return __spin_trylock(lock);
}
EXPORT_SYMBOL(_spin_trylock);
#endif
#ifndef CONFIG_INLINE_READ_TRYLOCK
int __lockfunc _read_trylock(rwlock_t *lock)
{
return __read_trylock(lock);
}
EXPORT_SYMBOL(_read_trylock);
#endif
#ifndef CONFIG_INLINE_WRITE_TRYLOCK
int __lockfunc _write_trylock(rwlock_t *lock)
{
return __write_trylock(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)
{
__read_lock(lock);
}
EXPORT_SYMBOL(_read_lock);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
return __spin_lock_irqsave(lock);
}
EXPORT_SYMBOL(_spin_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
__spin_lock_irq(lock);
}
EXPORT_SYMBOL(_spin_lock_irq);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_BH
void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
__spin_lock_bh(lock);
}
EXPORT_SYMBOL(_spin_lock_bh);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
return __read_lock_irqsave(lock);
}
EXPORT_SYMBOL(_read_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_IRQ
void __lockfunc _read_lock_irq(rwlock_t *lock)
{
__read_lock_irq(lock);
}
EXPORT_SYMBOL(_read_lock_irq);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_BH
void __lockfunc _read_lock_bh(rwlock_t *lock)
{
__read_lock_bh(lock);
}
EXPORT_SYMBOL(_read_lock_bh);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
return __write_lock_irqsave(lock);
}
EXPORT_SYMBOL(_write_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
void __lockfunc _write_lock_irq(rwlock_t *lock)
{
__write_lock_irq(lock);
}
EXPORT_SYMBOL(_write_lock_irq);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_BH
void __lockfunc _write_lock_bh(rwlock_t *lock)
{
__write_lock_bh(lock);
}
EXPORT_SYMBOL(_write_lock_bh);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK
void __lockfunc _spin_lock(spinlock_t *lock)
{
__spin_lock(lock);
}
EXPORT_SYMBOL(_spin_lock);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK
void __lockfunc _write_lock(rwlock_t *lock)
{
__write_lock(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)
{
__spin_unlock(lock);
}
EXPORT_SYMBOL(_spin_unlock);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK
void __lockfunc _write_unlock(rwlock_t *lock)
{
__write_unlock(lock);
}
EXPORT_SYMBOL(_write_unlock);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK
void __lockfunc _read_unlock(rwlock_t *lock)
{
__read_unlock(lock);
}
EXPORT_SYMBOL(_read_unlock);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
__spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
__spin_unlock_irq(lock);
}
EXPORT_SYMBOL(_spin_unlock_irq);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
__spin_unlock_bh(lock);
}
EXPORT_SYMBOL(_spin_unlock_bh);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__read_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_read_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
__read_unlock_irq(lock);
}
EXPORT_SYMBOL(_read_unlock_irq);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_BH
void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
__read_unlock_bh(lock);
}
EXPORT_SYMBOL(_read_unlock_bh);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__write_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_write_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
__write_unlock_irq(lock);
}
EXPORT_SYMBOL(_write_unlock_irq);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
__write_unlock_bh(lock);
}
EXPORT_SYMBOL(_write_unlock_bh);
#endif
#ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
return __spin_trylock_bh(lock);
}
EXPORT_SYMBOL(_spin_trylock_bh);
#endif
notrace 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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