linux_dsm_epyc7002/include/linux/spinlock_up.h
Paul E. McKenney d3a024abbc locking: Remove spin_unlock_wait() generic definitions
There is no agreed-upon definition of spin_unlock_wait()'s semantics,
and it appears that all callers could do just as well with a lock/unlock
pair.  This commit therefore removes spin_unlock_wait() and related
definitions from core code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-17 08:08:58 -07:00

84 lines
2.4 KiB
C

#ifndef __LINUX_SPINLOCK_UP_H
#define __LINUX_SPINLOCK_UP_H
#ifndef __LINUX_SPINLOCK_H
# error "please don't include this file directly"
#endif
#include <asm/processor.h> /* for cpu_relax() */
#include <asm/barrier.h>
/*
* include/linux/spinlock_up.h - UP-debug version of spinlocks.
*
* portions Copyright 2005, Red Hat, Inc., Ingo Molnar
* Released under the General Public License (GPL).
*
* In the debug case, 1 means unlocked, 0 means locked. (the values
* are inverted, to catch initialization bugs)
*
* No atomicity anywhere, we are on UP. However, we still need
* the compiler barriers, because we do not want the compiler to
* move potentially faulting instructions (notably user accesses)
* into the locked sequence, resulting in non-atomic execution.
*/
#ifdef CONFIG_DEBUG_SPINLOCK
#define arch_spin_is_locked(x) ((x)->slock == 0)
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
lock->slock = 0;
barrier();
}
static inline void
arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
{
local_irq_save(flags);
lock->slock = 0;
barrier();
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
char oldval = lock->slock;
lock->slock = 0;
barrier();
return oldval > 0;
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
barrier();
lock->slock = 1;
}
/*
* Read-write spinlocks. No debug version.
*/
#define arch_read_lock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_write_lock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_read_trylock(lock) ({ barrier(); (void)(lock); 1; })
#define arch_write_trylock(lock) ({ barrier(); (void)(lock); 1; })
#define arch_read_unlock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_write_unlock(lock) do { barrier(); (void)(lock); } while (0)
#else /* DEBUG_SPINLOCK */
#define arch_spin_is_locked(lock) ((void)(lock), 0)
/* for sched/core.c and kernel_lock.c: */
# define arch_spin_lock(lock) do { barrier(); (void)(lock); } while (0)
# define arch_spin_lock_flags(lock, flags) do { barrier(); (void)(lock); } while (0)
# define arch_spin_unlock(lock) do { barrier(); (void)(lock); } while (0)
# define arch_spin_trylock(lock) ({ barrier(); (void)(lock); 1; })
#endif /* DEBUG_SPINLOCK */
#define arch_spin_is_contended(lock) (((void)(lock), 0))
#define arch_read_can_lock(lock) (((void)(lock), 1))
#define arch_write_can_lock(lock) (((void)(lock), 1))
#endif /* __LINUX_SPINLOCK_UP_H */