linux/kernel/locking/spinlock.c
Minchan Kim 4a57d6bbae locking/rwlocks: introduce write_lock_nested
In preparation for converting bit_spin_lock to rwlock in zsmalloc so
that multiple writers of zspages can run at the same time but those
zspages are supposed to be different zspage instance.  Thus, it's not
deadlock.  This patch adds write_lock_nested to support the case for
LOCKDEP.

[minchan@kernel.org: fix write_lock_nested for RT]
  Link: https://lkml.kernel.org/r/YZfrMTAXV56HFWJY@google.com
[bigeasy@linutronix.de: fixup write_lock_nested() implementation]
  Link: https://lkml.kernel.org/r/20211123170134.y6xb7pmpgdn4m3bn@linutronix.de

Link: https://lkml.kernel.org/r/20211115185909.3949505-8-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-22 08:33:37 +02:00

416 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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/export.h>
#ifdef CONFIG_MMIOWB
#ifndef arch_mmiowb_state
DEFINE_PER_CPU(struct mmiowb_state, __mmiowb_state);
EXPORT_PER_CPU_SYMBOL(__mmiowb_state);
#endif
#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)
/*
* The __lock_function inlines are taken from
* spinlock : include/linux/spinlock_api_smp.h
* rwlock : include/linux/rwlock_api_smp.h
*/
#else
/*
* Some architectures can relax in favour of the CPU owning the lock.
*/
#ifndef arch_read_relax
# define arch_read_relax(l) cpu_relax()
#endif
#ifndef arch_write_relax
# define arch_write_relax(l) cpu_relax()
#endif
#ifndef arch_spin_relax
# define arch_spin_relax(l) cpu_relax()
#endif
/*
* 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 embeds 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 preemptible 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 __raw_##op##_lock(locktype##_t *lock) \
{ \
for (;;) { \
preempt_disable(); \
if (likely(do_raw_##op##_trylock(lock))) \
break; \
preempt_enable(); \
\
arch_##op##_relax(&lock->raw_lock); \
} \
} \
\
unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
{ \
unsigned long flags; \
\
for (;;) { \
preempt_disable(); \
local_irq_save(flags); \
if (likely(do_raw_##op##_trylock(lock))) \
break; \
local_irq_restore(flags); \
preempt_enable(); \
\
arch_##op##_relax(&lock->raw_lock); \
} \
\
return flags; \
} \
\
void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
{ \
_raw_##op##_lock_irqsave(lock); \
} \
\
void __lockfunc __raw_##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 = _raw_##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, raw_spinlock);
#ifndef CONFIG_PREEMPT_RT
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
#endif
#endif
#ifndef CONFIG_INLINE_SPIN_TRYLOCK
int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
{
return __raw_spin_trylock(lock);
}
EXPORT_SYMBOL(_raw_spin_trylock);
#endif
#ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)
{
return __raw_spin_trylock_bh(lock);
}
EXPORT_SYMBOL(_raw_spin_trylock_bh);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK
void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)
{
__raw_spin_lock(lock);
}
EXPORT_SYMBOL(_raw_spin_lock);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)
{
return __raw_spin_lock_irqsave(lock);
}
EXPORT_SYMBOL(_raw_spin_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)
{
__raw_spin_lock_irq(lock);
}
EXPORT_SYMBOL(_raw_spin_lock_irq);
#endif
#ifndef CONFIG_INLINE_SPIN_LOCK_BH
void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)
{
__raw_spin_lock_bh(lock);
}
EXPORT_SYMBOL(_raw_spin_lock_bh);
#endif
#ifdef CONFIG_UNINLINE_SPIN_UNLOCK
void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)
{
__raw_spin_unlock(lock);
}
EXPORT_SYMBOL(_raw_spin_unlock);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
{
__raw_spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)
{
__raw_spin_unlock_irq(lock);
}
EXPORT_SYMBOL(_raw_spin_unlock_irq);
#endif
#ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
{
__raw_spin_unlock_bh(lock);
}
EXPORT_SYMBOL(_raw_spin_unlock_bh);
#endif
#ifndef CONFIG_PREEMPT_RT
#ifndef CONFIG_INLINE_READ_TRYLOCK
int __lockfunc _raw_read_trylock(rwlock_t *lock)
{
return __raw_read_trylock(lock);
}
EXPORT_SYMBOL(_raw_read_trylock);
#endif
#ifndef CONFIG_INLINE_READ_LOCK
void __lockfunc _raw_read_lock(rwlock_t *lock)
{
__raw_read_lock(lock);
}
EXPORT_SYMBOL(_raw_read_lock);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)
{
return __raw_read_lock_irqsave(lock);
}
EXPORT_SYMBOL(_raw_read_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_IRQ
void __lockfunc _raw_read_lock_irq(rwlock_t *lock)
{
__raw_read_lock_irq(lock);
}
EXPORT_SYMBOL(_raw_read_lock_irq);
#endif
#ifndef CONFIG_INLINE_READ_LOCK_BH
void __lockfunc _raw_read_lock_bh(rwlock_t *lock)
{
__raw_read_lock_bh(lock);
}
EXPORT_SYMBOL(_raw_read_lock_bh);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK
void __lockfunc _raw_read_unlock(rwlock_t *lock)
{
__raw_read_unlock(lock);
}
EXPORT_SYMBOL(_raw_read_unlock);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__raw_read_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_raw_read_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)
{
__raw_read_unlock_irq(lock);
}
EXPORT_SYMBOL(_raw_read_unlock_irq);
#endif
#ifndef CONFIG_INLINE_READ_UNLOCK_BH
void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)
{
__raw_read_unlock_bh(lock);
}
EXPORT_SYMBOL(_raw_read_unlock_bh);
#endif
#ifndef CONFIG_INLINE_WRITE_TRYLOCK
int __lockfunc _raw_write_trylock(rwlock_t *lock)
{
return __raw_write_trylock(lock);
}
EXPORT_SYMBOL(_raw_write_trylock);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK
void __lockfunc _raw_write_lock(rwlock_t *lock)
{
__raw_write_lock(lock);
}
EXPORT_SYMBOL(_raw_write_lock);
#ifndef CONFIG_DEBUG_LOCK_ALLOC
#define __raw_write_lock_nested(lock, subclass) __raw_write_lock(((void)(subclass), (lock)))
#endif
void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)
{
__raw_write_lock_nested(lock, subclass);
}
EXPORT_SYMBOL(_raw_write_lock_nested);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)
{
return __raw_write_lock_irqsave(lock);
}
EXPORT_SYMBOL(_raw_write_lock_irqsave);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
void __lockfunc _raw_write_lock_irq(rwlock_t *lock)
{
__raw_write_lock_irq(lock);
}
EXPORT_SYMBOL(_raw_write_lock_irq);
#endif
#ifndef CONFIG_INLINE_WRITE_LOCK_BH
void __lockfunc _raw_write_lock_bh(rwlock_t *lock)
{
__raw_write_lock_bh(lock);
}
EXPORT_SYMBOL(_raw_write_lock_bh);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK
void __lockfunc _raw_write_unlock(rwlock_t *lock)
{
__raw_write_unlock(lock);
}
EXPORT_SYMBOL(_raw_write_unlock);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__raw_write_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_raw_write_unlock_irqrestore);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)
{
__raw_write_unlock_irq(lock);
}
EXPORT_SYMBOL(_raw_write_unlock_irq);
#endif
#ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
{
__raw_write_unlock_bh(lock);
}
EXPORT_SYMBOL(_raw_write_unlock_bh);
#endif
#endif /* !CONFIG_PREEMPT_RT */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
{
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
}
EXPORT_SYMBOL(_raw_spin_lock_nested);
unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_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(lock, do_raw_spin_trylock, do_raw_spin_lock);
return flags;
}
EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);
void __lockfunc _raw_spin_lock_nest_lock(raw_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, do_raw_spin_trylock, do_raw_spin_lock);
}
EXPORT_SYMBOL(_raw_spin_lock_nest_lock);
#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);