forked from Minki/linux
4ec45856b6
Generic code will construct {,_acquire,_release} versions by adding the
required smp_mb__{before,after}_atomic() calls.
XXX if/when MIPS will start using their new SYNCxx instructions they
can provide custom __atomic_op_{acquire,release}() macros as per the
powerpc example.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
719 lines
20 KiB
C
719 lines
20 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, 06 by Ralf Baechle
|
|
*/
|
|
#ifndef _ASM_ATOMIC_H
|
|
#define _ASM_ATOMIC_H
|
|
|
|
#include <linux/irqflags.h>
|
|
#include <linux/types.h>
|
|
#include <asm/barrier.h>
|
|
#include <asm/compiler.h>
|
|
#include <asm/cpu-features.h>
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/war.h>
|
|
|
|
#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) READ_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.
|
|
*/
|
|
#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i))
|
|
|
|
#define ATOMIC_OP(op, c_op, asm_op) \
|
|
static __inline__ void atomic_##op(int i, atomic_t * v) \
|
|
{ \
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
int temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: ll %0, %1 # atomic_" #op " \n" \
|
|
" " #asm_op " %0, %2 \n" \
|
|
" sc %0, %1 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
int temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" ll %0, %1 # atomic_" #op "\n" \
|
|
" " #asm_op " %0, %2 \n" \
|
|
" sc %0, %1 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} while (unlikely(!temp)); \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
v->counter c_op i; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
}
|
|
|
|
#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
|
|
static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
|
|
{ \
|
|
int result; \
|
|
\
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
int temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: ll %1, %2 # atomic_" #op "_return \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" sc %0, %2 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
int temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" ll %1, %2 # atomic_" #op "_return \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" sc %0, %2 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} while (unlikely(!result)); \
|
|
\
|
|
result = temp; result c_op i; \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
result = v->counter; \
|
|
result c_op i; \
|
|
v->counter = result; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
\
|
|
return result; \
|
|
}
|
|
|
|
#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
|
|
static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \
|
|
{ \
|
|
int result; \
|
|
\
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
int temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: ll %1, %2 # atomic_fetch_" #op " \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" sc %0, %2 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" move %0, %1 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
int temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" ll %1, %2 # atomic_fetch_" #op " \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" sc %0, %2 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} while (unlikely(!result)); \
|
|
\
|
|
result = temp; \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
result = v->counter; \
|
|
v->counter c_op i; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
\
|
|
return result; \
|
|
}
|
|
|
|
#define ATOMIC_OPS(op, c_op, asm_op) \
|
|
ATOMIC_OP(op, c_op, asm_op) \
|
|
ATOMIC_OP_RETURN(op, c_op, asm_op) \
|
|
ATOMIC_FETCH_OP(op, c_op, asm_op)
|
|
|
|
ATOMIC_OPS(add, +=, addu)
|
|
ATOMIC_OPS(sub, -=, subu)
|
|
|
|
#define atomic_add_return_relaxed atomic_add_return_relaxed
|
|
#define atomic_sub_return_relaxed atomic_sub_return_relaxed
|
|
#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
|
|
#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
|
|
|
|
#undef ATOMIC_OPS
|
|
#define ATOMIC_OPS(op, c_op, asm_op) \
|
|
ATOMIC_OP(op, c_op, asm_op) \
|
|
ATOMIC_FETCH_OP(op, c_op, asm_op)
|
|
|
|
ATOMIC_OPS(and, &=, and)
|
|
ATOMIC_OPS(or, |=, or)
|
|
ATOMIC_OPS(xor, ^=, xor)
|
|
|
|
#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
|
|
#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
|
|
#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
|
|
|
|
#undef ATOMIC_OPS
|
|
#undef ATOMIC_FETCH_OP
|
|
#undef ATOMIC_OP_RETURN
|
|
#undef ATOMIC_OP
|
|
|
|
/*
|
|
* atomic_sub_if_positive - conditionally subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically test @v and subtract @i if @v is greater or equal than @i.
|
|
* The function returns the old value of @v minus @i.
|
|
*/
|
|
static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
|
|
{
|
|
int result;
|
|
|
|
smp_mb__before_llsc();
|
|
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
int temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: ll %1, %2 # atomic_sub_if_positive\n"
|
|
" subu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" sc %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqzl %0, 1b \n"
|
|
" subu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp),
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "memory");
|
|
} else if (kernel_uses_llsc) {
|
|
int temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set "MIPS_ISA_LEVEL" \n"
|
|
"1: ll %1, %2 # atomic_sub_if_positive\n"
|
|
" subu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" sc %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqz %0, 1b \n"
|
|
" subu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp),
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "Ir" (i));
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
result = v->counter;
|
|
result -= i;
|
|
if (result >= 0)
|
|
v->counter = result;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
|
|
smp_llsc_mb();
|
|
|
|
return result;
|
|
}
|
|
|
|
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
|
|
#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
|
|
|
|
/**
|
|
* __atomic_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as it was not @u.
|
|
* Returns the old value of @v.
|
|
*/
|
|
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
|
|
{
|
|
int c, old;
|
|
c = atomic_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c;
|
|
}
|
|
|
|
#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_64BIT
|
|
|
|
#define ATOMIC64_INIT(i) { (i) }
|
|
|
|
/*
|
|
* atomic64_read - read atomic variable
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
*/
|
|
#define atomic64_read(v) READ_ONCE((v)->counter)
|
|
|
|
/*
|
|
* atomic64_set - set atomic variable
|
|
* @v: pointer of type atomic64_t
|
|
* @i: required value
|
|
*/
|
|
#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
|
|
|
|
#define ATOMIC64_OP(op, c_op, asm_op) \
|
|
static __inline__ void atomic64_##op(long i, atomic64_t * v) \
|
|
{ \
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
long temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: lld %0, %1 # atomic64_" #op " \n" \
|
|
" " #asm_op " %0, %2 \n" \
|
|
" scd %0, %1 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
long temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" lld %0, %1 # atomic64_" #op "\n" \
|
|
" " #asm_op " %0, %2 \n" \
|
|
" scd %0, %1 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} while (unlikely(!temp)); \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
v->counter c_op i; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
}
|
|
|
|
#define ATOMIC64_OP_RETURN(op, c_op, asm_op) \
|
|
static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \
|
|
{ \
|
|
long result; \
|
|
\
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
long temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: lld %1, %2 # atomic64_" #op "_return\n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" scd %0, %2 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
long temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" lld %1, %2 # atomic64_" #op "_return\n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" scd %0, %2 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"=" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "memory"); \
|
|
} while (unlikely(!result)); \
|
|
\
|
|
result = temp; result c_op i; \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
result = v->counter; \
|
|
result c_op i; \
|
|
v->counter = result; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
\
|
|
return result; \
|
|
}
|
|
|
|
#define ATOMIC64_FETCH_OP(op, c_op, asm_op) \
|
|
static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \
|
|
{ \
|
|
long result; \
|
|
\
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) { \
|
|
long temp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
" .set arch=r4000 \n" \
|
|
"1: lld %1, %2 # atomic64_fetch_" #op "\n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" scd %0, %2 \n" \
|
|
" beqzl %0, 1b \n" \
|
|
" move %0, %1 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i)); \
|
|
} else if (kernel_uses_llsc) { \
|
|
long temp; \
|
|
\
|
|
do { \
|
|
__asm__ __volatile__( \
|
|
" .set "MIPS_ISA_LEVEL" \n" \
|
|
" lld %1, %2 # atomic64_fetch_" #op "\n" \
|
|
" " #asm_op " %0, %1, %3 \n" \
|
|
" scd %0, %2 \n" \
|
|
" .set mips0 \n" \
|
|
: "=&r" (result), "=&r" (temp), \
|
|
"=" GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
|
|
: "memory"); \
|
|
} while (unlikely(!result)); \
|
|
\
|
|
result = temp; \
|
|
} else { \
|
|
unsigned long flags; \
|
|
\
|
|
raw_local_irq_save(flags); \
|
|
result = v->counter; \
|
|
v->counter c_op i; \
|
|
raw_local_irq_restore(flags); \
|
|
} \
|
|
\
|
|
return result; \
|
|
}
|
|
|
|
#define ATOMIC64_OPS(op, c_op, asm_op) \
|
|
ATOMIC64_OP(op, c_op, asm_op) \
|
|
ATOMIC64_OP_RETURN(op, c_op, asm_op) \
|
|
ATOMIC64_FETCH_OP(op, c_op, asm_op)
|
|
|
|
ATOMIC64_OPS(add, +=, daddu)
|
|
ATOMIC64_OPS(sub, -=, dsubu)
|
|
|
|
#define atomic64_add_return_relaxed atomic64_add_return_relaxed
|
|
#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
|
|
#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
|
|
#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
|
|
|
|
#undef ATOMIC64_OPS
|
|
#define ATOMIC64_OPS(op, c_op, asm_op) \
|
|
ATOMIC64_OP(op, c_op, asm_op) \
|
|
ATOMIC64_FETCH_OP(op, c_op, asm_op)
|
|
|
|
ATOMIC64_OPS(and, &=, and)
|
|
ATOMIC64_OPS(or, |=, or)
|
|
ATOMIC64_OPS(xor, ^=, xor)
|
|
|
|
#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
|
|
#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
|
|
#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
|
|
|
|
#undef ATOMIC64_OPS
|
|
#undef ATOMIC64_FETCH_OP
|
|
#undef ATOMIC64_OP_RETURN
|
|
#undef ATOMIC64_OP
|
|
|
|
/*
|
|
* atomic64_sub_if_positive - conditionally subtract integer from atomic
|
|
* variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically test @v and subtract @i if @v is greater or equal than @i.
|
|
* The function returns the old value of @v minus @i.
|
|
*/
|
|
static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
|
|
{
|
|
long result;
|
|
|
|
smp_mb__before_llsc();
|
|
|
|
if (kernel_uses_llsc && R10000_LLSC_WAR) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set arch=r4000 \n"
|
|
"1: lld %1, %2 # atomic64_sub_if_positive\n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" scd %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqzl %0, 1b \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp),
|
|
"=" GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "memory");
|
|
} else if (kernel_uses_llsc) {
|
|
long temp;
|
|
|
|
__asm__ __volatile__(
|
|
" .set "MIPS_ISA_LEVEL" \n"
|
|
"1: lld %1, %2 # atomic64_sub_if_positive\n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" bltz %0, 1f \n"
|
|
" scd %0, %2 \n"
|
|
" .set noreorder \n"
|
|
" beqz %0, 1b \n"
|
|
" dsubu %0, %1, %3 \n"
|
|
" .set reorder \n"
|
|
"1: \n"
|
|
" .set mips0 \n"
|
|
: "=&r" (result), "=&r" (temp),
|
|
"+" GCC_OFF_SMALL_ASM() (v->counter)
|
|
: "Ir" (i));
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
result = v->counter;
|
|
result -= i;
|
|
if (result >= 0)
|
|
v->counter = result;
|
|
raw_local_irq_restore(flags);
|
|
}
|
|
|
|
smp_llsc_mb();
|
|
|
|
return result;
|
|
}
|
|
|
|
#define atomic64_cmpxchg(v, o, n) \
|
|
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
|
|
#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
|
|
|
|
/**
|
|
* atomic64_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic64_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as it was not @u.
|
|
* Returns true iff @v was not @u.
|
|
*/
|
|
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
|
|
{
|
|
long c, old;
|
|
c = atomic64_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic64_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
|
|
|
|
#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_64BIT */
|
|
|
|
#endif /* _ASM_ATOMIC_H */
|