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/* MN10300 Atomic counter operations
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H
#include <asm/irqflags.h>
#include <asm/cmpxchg.h>
#ifndef CONFIG_SMP
#include <asm-generic/atomic.h>
#else
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
#define ATOMIC_INIT(i) { (i) }
#ifdef __KERNEL__
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
#define atomic_read(v) (ACCESS_ONCE((v)->counter))
/**
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
#define atomic_set(v, i) (((v)->counter) = (i))
/**
* atomic_add_return - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v and returns the result
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
*/
static inline int atomic_add_return(int i, atomic_t *v)
{
int retval;
#ifdef CONFIG_SMP
int status;
asm volatile(
"1: mov %4,(_AAR,%3) \n"
" mov (_ADR,%3),%1 \n"
" add %5,%1 \n"
" mov %1,(_ADR,%3) \n"
" mov (_ADR,%3),%0 \n" /* flush */
" mov (_ASR,%3),%0 \n"
" or %0,%0 \n"
" bne 1b \n"
: "=&r"(status), "=&r"(retval), "=m"(v->counter)
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
: "memory", "cc");
#else
unsigned long flags;
flags = arch_local_cli_save();
retval = v->counter;
retval += i;
v->counter = retval;
arch_local_irq_restore(flags);
#endif
return retval;
}
/**
* atomic_sub_return - subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns the result
* Note that the guaranteed useful range of an atomic_t is only 24 bits.
*/
static inline int atomic_sub_return(int i, atomic_t *v)
{
int retval;
#ifdef CONFIG_SMP
int status;
asm volatile(
"1: mov %4,(_AAR,%3) \n"
" mov (_ADR,%3),%1 \n"
" sub %5,%1 \n"
" mov %1,(_ADR,%3) \n"
" mov (_ADR,%3),%0 \n" /* flush */
" mov (_ASR,%3),%0 \n"
" or %0,%0 \n"
" bne 1b \n"
: "=&r"(status), "=&r"(retval), "=m"(v->counter)
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
: "memory", "cc");
#else
unsigned long flags;
flags = arch_local_cli_save();
retval = v->counter;
retval -= i;
v->counter = retval;
arch_local_irq_restore(flags);
#endif
return retval;
}
static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}
static inline void atomic_add(int i, atomic_t *v)
{
atomic_add_return(i, v);
}
static inline void atomic_sub(int i, atomic_t *v)
{
atomic_sub_return(i, v);
}
static inline void atomic_inc(atomic_t *v)
{
atomic_add_return(1, v);
}
static inline void atomic_dec(atomic_t *v)
{
atomic_sub_return(1, v);
}
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
#define __atomic_add_unless(v, a, u) \
({ \
int c, old; \
c = atomic_read(v); \
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
c = old; \
c; \
})
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
/**
* atomic_clear_mask - Atomically clear bits in memory
* @mask: Mask of the bits to be cleared
* @v: pointer to word in memory
*
* Atomically clears the bits set in mask from the memory word specified.
*/
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
{
#ifdef CONFIG_SMP
int status;
asm volatile(
"1: mov %3,(_AAR,%2) \n"
" mov (_ADR,%2),%0 \n"
" and %4,%0 \n"
" mov %0,(_ADR,%2) \n"
" mov (_ADR,%2),%0 \n" /* flush */
" mov (_ASR,%2),%0 \n"
" or %0,%0 \n"
" bne 1b \n"
: "=&r"(status), "=m"(*addr)
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(~mask)
: "memory", "cc");
#else
unsigned long flags;
mask = ~mask;
flags = arch_local_cli_save();
*addr &= mask;
arch_local_irq_restore(flags);
#endif
}
/**
* atomic_set_mask - Atomically set bits in memory
* @mask: Mask of the bits to be set
* @v: pointer to word in memory
*
* Atomically sets the bits set in mask from the memory word specified.
*/
static inline void atomic_set_mask(unsigned long mask, unsigned long *addr)
{
#ifdef CONFIG_SMP
int status;
asm volatile(
"1: mov %3,(_AAR,%2) \n"
" mov (_ADR,%2),%0 \n"
" or %4,%0 \n"
" mov %0,(_ADR,%2) \n"
" mov (_ADR,%2),%0 \n" /* flush */
" mov (_ASR,%2),%0 \n"
" or %0,%0 \n"
" bne 1b \n"
: "=&r"(status), "=m"(*addr)
: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(mask)
: "memory", "cc");
#else
unsigned long flags;
flags = arch_local_cli_save();
*addr |= mask;
arch_local_irq_restore(flags);
#endif
}
/* Atomic operations are already serializing on MN10300??? */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
#endif /* __KERNEL__ */
#endif /* CONFIG_SMP */
#endif /* _ASM_ATOMIC_H */
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