![Linus Torvalds](/assets/img/avatar_default.png)
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!
372 lines
7.6 KiB
C
372 lines
7.6 KiB
C
/*
|
|
* 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);
|