#ifndef __M68K_SPINLOCK_H
#define __M68K_SPINLOCK_H

/*
 * We don't do SMP on the m68k .... at least not yet.
 */

/*
 * Gcc-2.7.x has a nasty bug with empty initializers.
 */
#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
typedef struct { } spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { }
#else
typedef struct { int gcc_is_buggy; } spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
#endif

#define spin_lock_init(lock)	do { } while(0)
#define spin_lock(lock)		(void)(lock) /* Not "unused variable". */
#define spin_trylock(lock)	(1)
#define spin_unlock_wait(lock)	do { } while(0)
#define spin_unlock(lock)	do { } while(0)
#define spin_lock_irq(lock)	cli()
#define spin_unlock_irq(lock)	sti()
#define spin_lock_bh(lock)	local_bh_disable()
#define spin_unlock_bh(lock)	local_bh_enable()

#define spin_lock_irqsave(lock, flags) \
	do { save_flags(flags); cli(); } while (0)
#define spin_unlock_irqrestore(lock, flags) \
	restore_flags(flags)

/*
 * Read-write spinlocks, allowing multiple readers
 * but only one writer.
 *
 * NOTE! it is quite common to have readers in interrupts
 * but no interrupt writers. For those circumstances we
 * can "mix" irq-safe locks - any writer needs to get a
 * irq-safe write-lock, but readers can get non-irqsafe
 * read-locks.
 *
 * Gcc-2.7.x has a nasty bug with empty initializers.
 */
#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
typedef struct { } rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { }
#else
typedef struct { int gcc_is_buggy; } rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
#endif

#define read_lock(lock)		(void)(lock) /* Not "unused variable". */
#define read_unlock(lock)	do { } while(0)
#define write_lock(lock)	(void)(lock) /* Not "unused variable". */
#define write_unlock(lock)	do { } while(0)
#define read_lock_irq(lock)	cli()
#define read_unlock_irq(lock)	sti()
#define write_lock_irq(lock)	cli()
#define write_unlock_irq(lock)	sti()
#define read_lock_bh(lock)	local_bh_disable()
#define read_unlock_bh(lock)	local_bh_enable()
#define write_lock_bh(lock)	local_bh_disable()
#define write_unlock_bh(lock)	local_bh_enable()

#define read_lock_irqsave(lock, flags)		save_and_cli(flags)
#define read_unlock_irqrestore(lock, flags)	restore_flags(flags)
#define write_lock_irqsave(lock, flags)		save_and_cli(flags)
#define write_unlock_irqrestore(lock, flags)	restore_flags(flags)

#endif
