include/asm-m68knommu/tlbflush.h


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#ifndef _M68KNOMMU_TLBFLUSH_H
#define _M68KNOMMU_TLBFLUSH_H

/*
 * Copyright (C) 2000 Lineo, David McCullough <davidm@uclinux.org>
 * Copyright (C) 2000-2002, Greg Ungerer <gerg@snapgear.com>
 */

#include <asm/setup.h>

/*
 * flush all user-space atc entries.
 */
static inline void __flush_tlb(void)
{
	BUG();
}

static inline void __flush_tlb_one(unsigned long addr)
{
	BUG();
}

#define flush_tlb() __flush_tlb()

/*
 * flush all atc entries (both kernel and user-space entries).
 */
static inline void flush_tlb_all(void)
{
	BUG();
}

static inline void flush_tlb_mm(struct mm_struct *mm)
{
	BUG();
}

static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
{
	BUG();
}

static inline void flush_tlb_range(struct mm_struct *mm,
				   unsigned long start, unsigned long end)
{
	BUG();
}

static inline void flush_tlb_kernel_page(unsigned long addr)
{
	BUG();
}

static inline void flush_tlb_pgtables(struct mm_struct *mm,
				      unsigned long start, unsigned long end)
{
	BUG();
}

#endif /* _M68KNOMMU_TLBFLUSH_H */
/* kernel/rwsem.c: R/W semaphores, public implementation
 *
 * Written by David Howells (dhowells@redhat.com).
 * Derived from asm-i386/semaphore.h
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/export.h>
#include <linux/rwsem.h>

#include <linux/atomic.h>

/*
 * lock for reading
 */
void __sched down_read(struct rw_semaphore *sem)
{
	might_sleep();
	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);

	LOCK_CONTENDED(sem, __down_read_trylock, __down_read);
}

EXPORT_SYMBOL(down_read);

/*
 * trylock for reading -- returns 1 if successful, 0 if contention
 */
int down_read_trylock(struct rw_semaphore *sem)
{
	int ret = __down_read_trylock(sem);

	if (ret == 1)
		rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
	return ret;
}

EXPORT_SYMBOL(down_read_trylock);

/*
 * lock for writing
 */
void __sched down_write(struct rw_semaphore *sem)
{
	might_sleep();
	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);

	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
}

EXPORT_SYMBOL(down_write);

/*
 * trylock for writing -- returns 1 if successful, 0 if contention
 */
int down_write_trylock(struct rw_semaphore *sem)
{
	int ret = __down_write_trylock(sem);

	if (ret == 1)
		rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
	return ret;
}

EXPORT_SYMBOL(down_write_trylock);

/*
 * release a read lock
 */
void up_read(struct rw_semaphore *sem)
{
	rwsem_release(&sem->dep_map, 1, _RET_IP_);

	__up_read(sem);
}

EXPORT_SYMBOL(up_read);

/*
 * release a write lock
 */
void up_write(struct rw_semaphore *sem)
{
	rwsem_release(&sem->dep_map, 1, _RET_IP_);

	__up_write(sem);
}

EXPORT_SYMBOL(up_write);

/*
 * downgrade write lock to read lock
 */
void downgrade_write(struct rw_semaphore *sem)
{
	/*
	 * lockdep: a downgraded write will live on as a write
	 * dependency.
	 */
	__downgrade_write(sem);
}

EXPORT_SYMBOL(downgrade_write);

#ifdef CONFIG_DEBUG_LOCK_ALLOC

void down_read_nested(struct rw_semaphore *sem, int subclass)
{
	might_sleep();
	rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_);

	LOCK_CONTENDED(sem, __down_read_trylock, __down_read);
}

EXPORT_SYMBOL(down_read_nested);

void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest)
{
	might_sleep();
	rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_);

	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
}

EXPORT_SYMBOL(_down_write_nest_lock);

void down_write_nested(struct rw_semaphore *sem, int subclass)
{
	might_sleep();
	rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_);

	LOCK_CONTENDED(sem, __down_write_trylock, __down_write);
}

EXPORT_SYMBOL(down_write_nested);

#endif