linux/arch/x86/include/asm/atomic64_64.h
Mark Rutland b3a2a05f91 atomics/treewide: Make conditional inc/dec ops optional
The conditional inc/dec ops differ for atomic_t and atomic64_t:

- atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t.

Let's make these consistently optional for both. At the same time, let's
clean up the existing fallbacks to use atomic_try_cmpxchg().

The instrumented atomics are updated accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-18-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 14:25:24 +02:00

246 lines
5.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_ATOMIC64_64_H
#define _ASM_X86_ATOMIC64_64_H
#include <linux/types.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
/* The 64-bit atomic type */
#define ATOMIC64_INIT(i) { (i) }
/**
* arch_atomic64_read - read atomic64 variable
* @v: pointer of type atomic64_t
*
* Atomically reads the value of @v.
* Doesn't imply a read memory barrier.
*/
static inline long arch_atomic64_read(const atomic64_t *v)
{
return READ_ONCE((v)->counter);
}
/**
* arch_atomic64_set - set atomic64 variable
* @v: pointer to type atomic64_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static inline void arch_atomic64_set(atomic64_t *v, long i)
{
WRITE_ONCE(v->counter, i);
}
/**
* arch_atomic64_add - add integer to atomic64 variable
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v.
*/
static __always_inline void arch_atomic64_add(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "addq %1,%0"
: "=m" (v->counter)
: "er" (i), "m" (v->counter));
}
/**
* arch_atomic64_sub - subtract the atomic64 variable
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @i from @v.
*/
static inline void arch_atomic64_sub(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "subq %1,%0"
: "=m" (v->counter)
: "er" (i), "m" (v->counter));
}
/**
* arch_atomic64_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define arch_atomic64_sub_and_test arch_atomic64_sub_and_test
static inline bool arch_atomic64_sub_and_test(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", e);
}
/**
* arch_atomic64_inc - increment atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically increments @v by 1.
*/
#define arch_atomic64_inc arch_atomic64_inc
static __always_inline void arch_atomic64_inc(atomic64_t *v)
{
asm volatile(LOCK_PREFIX "incq %0"
: "=m" (v->counter)
: "m" (v->counter));
}
/**
* arch_atomic64_dec - decrement atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically decrements @v by 1.
*/
#define arch_atomic64_dec arch_atomic64_dec
static __always_inline void arch_atomic64_dec(atomic64_t *v)
{
asm volatile(LOCK_PREFIX "decq %0"
: "=m" (v->counter)
: "m" (v->counter));
}
/**
* arch_atomic64_dec_and_test - decrement and test
* @v: pointer to type atomic64_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define arch_atomic64_dec_and_test arch_atomic64_dec_and_test
static inline bool arch_atomic64_dec_and_test(atomic64_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", e);
}
/**
* arch_atomic64_inc_and_test - increment and test
* @v: pointer to type atomic64_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define arch_atomic64_inc_and_test arch_atomic64_inc_and_test
static inline bool arch_atomic64_inc_and_test(atomic64_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", e);
}
/**
* arch_atomic64_add_negative - add and test if negative
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* 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 arch_atomic64_add_negative arch_atomic64_add_negative
static inline bool arch_atomic64_add_negative(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", s);
}
/**
* arch_atomic64_add_return - add and return
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v and returns @i + @v
*/
static __always_inline long arch_atomic64_add_return(long i, atomic64_t *v)
{
return i + xadd(&v->counter, i);
}
static inline long arch_atomic64_sub_return(long i, atomic64_t *v)
{
return arch_atomic64_add_return(-i, v);
}
static inline long arch_atomic64_fetch_add(long i, atomic64_t *v)
{
return xadd(&v->counter, i);
}
static inline long arch_atomic64_fetch_sub(long i, atomic64_t *v)
{
return xadd(&v->counter, -i);
}
static inline long arch_atomic64_cmpxchg(atomic64_t *v, long old, long new)
{
return arch_cmpxchg(&v->counter, old, new);
}
#define arch_atomic64_try_cmpxchg arch_atomic64_try_cmpxchg
static __always_inline bool arch_atomic64_try_cmpxchg(atomic64_t *v, s64 *old, long new)
{
return try_cmpxchg(&v->counter, old, new);
}
static inline long arch_atomic64_xchg(atomic64_t *v, long new)
{
return xchg(&v->counter, new);
}
static inline void arch_atomic64_and(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "andq %1,%0"
: "+m" (v->counter)
: "er" (i)
: "memory");
}
static inline long arch_atomic64_fetch_and(long i, atomic64_t *v)
{
s64 val = arch_atomic64_read(v);
do {
} while (!arch_atomic64_try_cmpxchg(v, &val, val & i));
return val;
}
static inline void arch_atomic64_or(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "orq %1,%0"
: "+m" (v->counter)
: "er" (i)
: "memory");
}
static inline long arch_atomic64_fetch_or(long i, atomic64_t *v)
{
s64 val = arch_atomic64_read(v);
do {
} while (!arch_atomic64_try_cmpxchg(v, &val, val | i));
return val;
}
static inline void arch_atomic64_xor(long i, atomic64_t *v)
{
asm volatile(LOCK_PREFIX "xorq %1,%0"
: "+m" (v->counter)
: "er" (i)
: "memory");
}
static inline long arch_atomic64_fetch_xor(long i, atomic64_t *v)
{
s64 val = arch_atomic64_read(v);
do {
} while (!arch_atomic64_try_cmpxchg(v, &val, val ^ i));
return val;
}
#endif /* _ASM_X86_ATOMIC64_64_H */