linux-stable/include/linux/spinlock_api_up.h
Sebastian Andrzej Siewior 2747b93ebb locking: Detect includes rwlock.h outside of spinlock.h
From: Michael S. Tsirkin <mst@redhat.com>

The check for __LINUX_SPINLOCK_H within rwlock.h (and other files)
detects the direct include of the header file if it is at the very
beginning of the include section.
If it is listed later then chances are high that spinlock.h was already
included (including rwlock.h) and the additional listing of rwlock.h
will not cause any failure.

On PREEMPT_RT this additional rwlock.h will lead to compile failures
since it uses a different rwlock implementation.

Add __LINUX_INSIDE_SPINLOCK_H to spinlock.h and check for this instead
of __LINUX_SPINLOCK_H to detect wrong includes. This will help detect
direct includes of rwlock.h with without PREEMPT_RT enabled.

[ bigeasy: add remaining __LINUX_SPINLOCK_H user and rewrite
  commit description. ]

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YweemHxJx7O8rjBx@linutronix.de
2022-09-15 16:14:02 +02:00

92 lines
3.4 KiB
C

#ifndef __LINUX_SPINLOCK_API_UP_H
#define __LINUX_SPINLOCK_API_UP_H
#ifndef __LINUX_INSIDE_SPINLOCK_H
# error "please don't include this file directly"
#endif
/*
* include/linux/spinlock_api_up.h
*
* spinlock API implementation on UP-nondebug (inlined implementation)
*
* portions Copyright 2005, Red Hat, Inc., Ingo Molnar
* Released under the General Public License (GPL).
*/
#define in_lock_functions(ADDR) 0
#define assert_raw_spin_locked(lock) do { (void)(lock); } while (0)
/*
* In the UP-nondebug case there's no real locking going on, so the
* only thing we have to do is to keep the preempt counts and irq
* flags straight, to suppress compiler warnings of unused lock
* variables, and to add the proper checker annotations:
*/
#define ___LOCK(lock) \
do { __acquire(lock); (void)(lock); } while (0)
#define __LOCK(lock) \
do { preempt_disable(); ___LOCK(lock); } while (0)
#define __LOCK_BH(lock) \
do { __local_bh_disable_ip(_THIS_IP_, SOFTIRQ_LOCK_OFFSET); ___LOCK(lock); } while (0)
#define __LOCK_IRQ(lock) \
do { local_irq_disable(); __LOCK(lock); } while (0)
#define __LOCK_IRQSAVE(lock, flags) \
do { local_irq_save(flags); __LOCK(lock); } while (0)
#define ___UNLOCK(lock) \
do { __release(lock); (void)(lock); } while (0)
#define __UNLOCK(lock) \
do { preempt_enable(); ___UNLOCK(lock); } while (0)
#define __UNLOCK_BH(lock) \
do { __local_bh_enable_ip(_THIS_IP_, SOFTIRQ_LOCK_OFFSET); \
___UNLOCK(lock); } while (0)
#define __UNLOCK_IRQ(lock) \
do { local_irq_enable(); __UNLOCK(lock); } while (0)
#define __UNLOCK_IRQRESTORE(lock, flags) \
do { local_irq_restore(flags); __UNLOCK(lock); } while (0)
#define _raw_spin_lock(lock) __LOCK(lock)
#define _raw_spin_lock_nested(lock, subclass) __LOCK(lock)
#define _raw_read_lock(lock) __LOCK(lock)
#define _raw_write_lock(lock) __LOCK(lock)
#define _raw_write_lock_nested(lock, subclass) __LOCK(lock)
#define _raw_spin_lock_bh(lock) __LOCK_BH(lock)
#define _raw_read_lock_bh(lock) __LOCK_BH(lock)
#define _raw_write_lock_bh(lock) __LOCK_BH(lock)
#define _raw_spin_lock_irq(lock) __LOCK_IRQ(lock)
#define _raw_read_lock_irq(lock) __LOCK_IRQ(lock)
#define _raw_write_lock_irq(lock) __LOCK_IRQ(lock)
#define _raw_spin_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags)
#define _raw_read_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags)
#define _raw_write_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags)
#define _raw_spin_trylock(lock) ({ __LOCK(lock); 1; })
#define _raw_read_trylock(lock) ({ __LOCK(lock); 1; })
#define _raw_write_trylock(lock) ({ __LOCK(lock); 1; })
#define _raw_spin_trylock_bh(lock) ({ __LOCK_BH(lock); 1; })
#define _raw_spin_unlock(lock) __UNLOCK(lock)
#define _raw_read_unlock(lock) __UNLOCK(lock)
#define _raw_write_unlock(lock) __UNLOCK(lock)
#define _raw_spin_unlock_bh(lock) __UNLOCK_BH(lock)
#define _raw_write_unlock_bh(lock) __UNLOCK_BH(lock)
#define _raw_read_unlock_bh(lock) __UNLOCK_BH(lock)
#define _raw_spin_unlock_irq(lock) __UNLOCK_IRQ(lock)
#define _raw_read_unlock_irq(lock) __UNLOCK_IRQ(lock)
#define _raw_write_unlock_irq(lock) __UNLOCK_IRQ(lock)
#define _raw_spin_unlock_irqrestore(lock, flags) \
__UNLOCK_IRQRESTORE(lock, flags)
#define _raw_read_unlock_irqrestore(lock, flags) \
__UNLOCK_IRQRESTORE(lock, flags)
#define _raw_write_unlock_irqrestore(lock, flags) \
__UNLOCK_IRQRESTORE(lock, flags)
#endif /* __LINUX_SPINLOCK_API_UP_H */