linux/include/asm-mips/atomic.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

653 lines
15 KiB
C

/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* But use these as seldom as possible since they are much more slower
* than regular operations.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 97, 99, 2000, 03, 04 by Ralf Baechle
*/
/*
* As workaround for the ATOMIC_DEC_AND_LOCK / atomic_dec_and_lock mess in
* <linux/spinlock.h> we have to include <linux/spinlock.h> outside the
* main big wrapper ...
*/
#include <linux/config.h>
#include <linux/spinlock.h>
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H
#include <asm/cpu-features.h>
#include <asm/war.h>
extern spinlock_t atomic_lock;
typedef struct { volatile int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
/*
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define atomic_read(v) ((v)->counter)
/*
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
#define atomic_set(v,i) ((v)->counter = (i))
/*
* atomic_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v.
*/
static __inline__ void atomic_add(int i, atomic_t * v)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %0, %1 # atomic_add \n"
" addu %0, %2 \n"
" sc %0, %1 \n"
" beqzl %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %0, %1 # atomic_add \n"
" addu %0, %2 \n"
" sc %0, %1 \n"
" beqz %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
v->counter += i;
spin_unlock_irqrestore(&atomic_lock, flags);
}
}
/*
* atomic_sub - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
static __inline__ void atomic_sub(int i, atomic_t * v)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %0, %1 # atomic_sub \n"
" subu %0, %2 \n"
" sc %0, %1 \n"
" beqzl %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %0, %1 # atomic_sub \n"
" subu %0, %2 \n"
" sc %0, %1 \n"
" beqz %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
v->counter -= i;
spin_unlock_irqrestore(&atomic_lock, flags);
}
}
/*
* Same as above, but return the result value
*/
static __inline__ int atomic_add_return(int i, atomic_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_add_return \n"
" addu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqzl %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_add_return \n"
" addu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqz %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result += i;
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
static __inline__ int atomic_sub_return(int i, atomic_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_return \n"
" subu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_return \n"
" subu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result -= i;
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
/*
* atomic_sub_if_positive - add integer to atomic variable
* @v: pointer of type atomic_t
*
* Atomically test @v and decrement if it is greater than 0.
* The function returns the old value of @v minus 1.
*/
static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_if_positive\n"
" subu %0, %1, %3 \n"
" bltz %0, 1f \n"
" sc %0, %2 \n"
" beqzl %0, 1b \n"
" sync \n"
"1: \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_if_positive\n"
" subu %0, %1, %3 \n"
" bltz %0, 1f \n"
" sc %0, %2 \n"
" beqz %0, 1b \n"
" sync \n"
"1: \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result -= i;
if (result >= 0)
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
#define atomic_dec_return(v) atomic_sub_return(1,(v))
#define atomic_inc_return(v) atomic_add_return(1,(v))
/*
* atomic_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
/*
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
/*
* atomic_dec_and_test - decrement by 1 and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
/*
* atomic_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
*/
#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
/*
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
#define atomic_inc(v) atomic_add(1,(v))
/*
* atomic_dec - decrement and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
#define atomic_dec(v) atomic_sub(1,(v))
/*
* atomic_add_negative - add and test if negative
* @v: pointer of type atomic_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define atomic_add_negative(i,v) (atomic_add_return(i, (v)) < 0)
#ifdef CONFIG_MIPS64
typedef struct { volatile __s64 counter; } atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
/*
* atomic64_read - read atomic variable
* @v: pointer of type atomic64_t
*
*/
#define atomic64_read(v) ((v)->counter)
/*
* atomic64_set - set atomic variable
* @v: pointer of type atomic64_t
* @i: required value
*/
#define atomic64_set(v,i) ((v)->counter = (i))
/*
* atomic64_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic64_t
*
* Atomically adds @i to @v.
*/
static __inline__ void atomic64_add(long i, atomic64_t * v)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %0, %1 # atomic64_add \n"
" addu %0, %2 \n"
" scd %0, %1 \n"
" beqzl %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %0, %1 # atomic64_add \n"
" addu %0, %2 \n"
" scd %0, %1 \n"
" beqz %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
v->counter += i;
spin_unlock_irqrestore(&atomic_lock, flags);
}
}
/*
* atomic64_sub - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic64_t
*
* Atomically subtracts @i from @v.
*/
static __inline__ void atomic64_sub(long i, atomic64_t * v)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %0, %1 # atomic64_sub \n"
" subu %0, %2 \n"
" scd %0, %1 \n"
" beqzl %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %0, %1 # atomic64_sub \n"
" subu %0, %2 \n"
" scd %0, %1 \n"
" beqz %0, 1b \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
v->counter -= i;
spin_unlock_irqrestore(&atomic_lock, flags);
}
}
/*
* Same as above, but return the result value
*/
static __inline__ long atomic64_add_return(long i, atomic64_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_add_return \n"
" addu %0, %1, %3 \n"
" scd %0, %2 \n"
" beqzl %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_add_return \n"
" addu %0, %1, %3 \n"
" scd %0, %2 \n"
" beqz %0, 1b \n"
" addu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result += i;
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_sub_return \n"
" subu %0, %1, %3 \n"
" scd %0, %2 \n"
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_sub_return \n"
" subu %0, %1, %3 \n"
" scd %0, %2 \n"
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" sync \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result -= i;
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
/*
* atomic64_sub_if_positive - add integer to atomic variable
* @v: pointer of type atomic64_t
*
* Atomically test @v and decrement if it is greater than 0.
* The function returns the old value of @v minus 1.
*/
static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
{
unsigned long result;
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
" scd %0, %2 \n"
" beqzl %0, 1b \n"
" sync \n"
"1: \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;
__asm__ __volatile__(
"1: lld %1, %2 # atomic64_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
" scd %0, %2 \n"
" beqz %0, 1b \n"
" sync \n"
"1: \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
} else {
unsigned long flags;
spin_lock_irqsave(&atomic_lock, flags);
result = v->counter;
result -= i;
if (result >= 0)
v->counter = result;
spin_unlock_irqrestore(&atomic_lock, flags);
}
return result;
}
#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
#define atomic64_inc_return(v) atomic64_add_return(1,(v))
/*
* atomic64_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic64_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
/*
* atomic64_inc_and_test - increment and test
* @v: pointer of type atomic64_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
/*
* atomic64_dec_and_test - decrement by 1 and test
* @v: pointer of type atomic64_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic64_t
*/
#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
/*
* atomic64_inc - increment atomic variable
* @v: pointer of type atomic64_t
*
* Atomically increments @v by 1.
*/
#define atomic64_inc(v) atomic64_add(1,(v))
/*
* atomic64_dec - decrement and test
* @v: pointer of type atomic64_t
*
* Atomically decrements @v by 1.
*/
#define atomic64_dec(v) atomic64_sub(1,(v))
/*
* atomic64_add_negative - add and test if negative
* @v: pointer of type atomic64_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define atomic64_add_negative(i,v) (atomic64_add_return(i, (v)) < 0)
#endif /* CONFIG_MIPS64 */
/*
* atomic*_return operations are serializing but not the non-*_return
* versions.
*/
#define smp_mb__before_atomic_dec() smp_mb()
#define smp_mb__after_atomic_dec() smp_mb()
#define smp_mb__before_atomic_inc() smp_mb()
#define smp_mb__after_atomic_inc() smp_mb()
#endif /* _ASM_ATOMIC_H */