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/*
* arch/s390/lib/spinlock.c
* Out of line spinlock code.
*
* Copyright (C) IBM Corp. 2004, 2006
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <asm/io.h>
int spin_retry = 1000;
/**
* spin_retry= parameter
*/
static int __init spin_retry_setup(char *str)
{
spin_retry = simple_strtoul(str, &str, 0);
return 1;
}
__setup("spin_retry=", spin_retry_setup);
static inline void
_diag44(void)
{
#ifdef CONFIG_64BIT
if (MACHINE_HAS_DIAG44)
#endif
asm volatile("diag 0,0,0x44");
}
void
_raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc)
{
int count = spin_retry;
while (1) {
if (count-- <= 0) {
_diag44();
count = spin_retry;
}
if (__raw_spin_is_locked(lp))
continue;
if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0)
return;
}
}
EXPORT_SYMBOL(_raw_spin_lock_wait);
int
_raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc)
{
int count = spin_retry;
while (count-- > 0) {
if (__raw_spin_is_locked(lp))
continue;
if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0)
return 1;
}
return 0;
}
EXPORT_SYMBOL(_raw_spin_trylock_retry);
void
_raw_read_lock_wait(raw_rwlock_t *rw)
{
unsigned int old;
int count = spin_retry;
while (1) {
if (count-- <= 0) {
_diag44();
count = spin_retry;
}
if (!__raw_read_can_lock(rw))
continue;
old = rw->lock & 0x7fffffffU;
if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
return;
}
}
EXPORT_SYMBOL(_raw_read_lock_wait);
int
_raw_read_trylock_retry(raw_rwlock_t *rw)
{
unsigned int old;
int count = spin_retry;
while (count-- > 0) {
if (!__raw_read_can_lock(rw))
continue;
old = rw->lock & 0x7fffffffU;
if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
return 1;
}
return 0;
}
EXPORT_SYMBOL(_raw_read_trylock_retry);
void
_raw_write_lock_wait(raw_rwlock_t *rw)
{
int count = spin_retry;
while (1) {
if (count-- <= 0) {
_diag44();
count = spin_retry;
}
if (!__raw_write_can_lock(rw))
continue;
if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
return;
}
}
EXPORT_SYMBOL(_raw_write_lock_wait);
int
_raw_write_trylock_retry(raw_rwlock_t *rw)
{
int count = spin_retry;
while (count-- > 0) {
if (!__raw_write_can_lock(rw))
continue;
if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
return 1;
}
return 0;
}
EXPORT_SYMBOL(_raw_write_trylock_retry);
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