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linux/arch/alpha/include/asm/atomic.h
Mark Rutland ef558b4b7b locking/atomic: treewide: delete arch_atomic_*() kerneldoc 
Currently several architectures have kerneldoc comments for
arch_atomic_*(), which is unhelpful as these live in a shared namespace
where they clash, and the arch_atomic_*() ops are now an implementation
detail of the raw_atomic_*() ops, which no-one should use those
directly.

Delete the kerneldoc comments for arch_atomic_*(), along with
pseudo-kerneldoc comments which are in the correct style but are missing
the leading '/**' necessary to be true kerneldoc comments.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230605070124.3741859-28-mark.rutland@arm.com
2023-06-05 09:57:24 +02:00

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ALPHA_ATOMIC_H
#define _ALPHA_ATOMIC_H
#include <linux/types.h>
#include <asm/barrier.h>
#include <asm/cmpxchg.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc...
*
* But use these as seldom as possible since they are much slower
* than regular operations.
*/
/*
* To ensure dependency ordering is preserved for the _relaxed and
* _release atomics, an smp_mb() is unconditionally inserted into the
* _relaxed variants, which are used to build the barriered versions.
* Avoid redundant back-to-back fences in the _acquire and _fence
* versions.
*/
#define __atomic_acquire_fence()
#define __atomic_post_full_fence()
#define ATOMIC64_INIT(i) { (i) }
#define arch_atomic_read(v) READ_ONCE((v)->counter)
#define arch_atomic64_read(v) READ_ONCE((v)->counter)
#define arch_atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
#define arch_atomic64_set(v,i) WRITE_ONCE((v)->counter, (i))
/*
* To get proper branch prediction for the main line, we must branch
* forward to code at the end of this object's .text section, then
* branch back to restart the operation.
*/
#define ATOMIC_OP(op, asm_op) \
static __inline__ void arch_atomic_##op(int i, atomic_t * v) \
{ \
unsigned long temp; \
__asm__ __volatile__( \
"1: ldl_l %0,%1\n" \
" " #asm_op " %0,%2,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter) \
:"Ir" (i), "m" (v->counter)); \
} \
#define ATOMIC_OP_RETURN(op, asm_op) \
static inline int arch_atomic_##op##_return_relaxed(int i, atomic_t *v) \
{ \
long temp, result; \
__asm__ __volatile__( \
"1: ldl_l %0,%1\n" \
" " #asm_op " %0,%3,%2\n" \
" " #asm_op " %0,%3,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_mb(); \
return result; \
}
#define ATOMIC_FETCH_OP(op, asm_op) \
static inline int arch_atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
{ \
long temp, result; \
__asm__ __volatile__( \
"1: ldl_l %2,%1\n" \
" " #asm_op " %2,%3,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_mb(); \
return result; \
}
#define ATOMIC64_OP(op, asm_op) \
static __inline__ void arch_atomic64_##op(s64 i, atomic64_t * v) \
{ \
s64 temp; \
__asm__ __volatile__( \
"1: ldq_l %0,%1\n" \
" " #asm_op " %0,%2,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter) \
:"Ir" (i), "m" (v->counter)); \
} \
#define ATOMIC64_OP_RETURN(op, asm_op) \
static __inline__ s64 \
arch_atomic64_##op##_return_relaxed(s64 i, atomic64_t * v) \
{ \
s64 temp, result; \
__asm__ __volatile__( \
"1: ldq_l %0,%1\n" \
" " #asm_op " %0,%3,%2\n" \
" " #asm_op " %0,%3,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_mb(); \
return result; \
}
#define ATOMIC64_FETCH_OP(op, asm_op) \
static __inline__ s64 \
arch_atomic64_fetch_##op##_relaxed(s64 i, atomic64_t * v) \
{ \
s64 temp, result; \
__asm__ __volatile__( \
"1: ldq_l %2,%1\n" \
" " #asm_op " %2,%3,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_mb(); \
return result; \
}
#define ATOMIC_OPS(op) \
ATOMIC_OP(op, op##l) \
ATOMIC_OP_RETURN(op, op##l) \
ATOMIC_FETCH_OP(op, op##l) \
ATOMIC64_OP(op, op##q) \
ATOMIC64_OP_RETURN(op, op##q) \
ATOMIC64_FETCH_OP(op, op##q)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed
#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed
#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed
#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed
#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed
#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed
#define arch_atomic64_fetch_add_relaxed arch_atomic64_fetch_add_relaxed
#define arch_atomic64_fetch_sub_relaxed arch_atomic64_fetch_sub_relaxed
#define arch_atomic_andnot arch_atomic_andnot
#define arch_atomic64_andnot arch_atomic64_andnot
#undef ATOMIC_OPS
#define ATOMIC_OPS(op, asm) \
ATOMIC_OP(op, asm) \
ATOMIC_FETCH_OP(op, asm) \
ATOMIC64_OP(op, asm) \
ATOMIC64_FETCH_OP(op, asm)
ATOMIC_OPS(and, and)
ATOMIC_OPS(andnot, bic)
ATOMIC_OPS(or, bis)
ATOMIC_OPS(xor, xor)
#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed
#define arch_atomic_fetch_andnot_relaxed arch_atomic_fetch_andnot_relaxed
#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed
#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed
#define arch_atomic64_fetch_and_relaxed arch_atomic64_fetch_and_relaxed
#define arch_atomic64_fetch_andnot_relaxed arch_atomic64_fetch_andnot_relaxed
#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed
#define arch_atomic64_fetch_xor_relaxed arch_atomic64_fetch_xor_relaxed
#undef ATOMIC_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
static __inline__ int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
{
int c, new, old;
smp_mb();
__asm__ __volatile__(
"1: ldl_l %[old],%[mem]\n"
" cmpeq %[old],%[u],%[c]\n"
" addl %[old],%[a],%[new]\n"
" bne %[c],2f\n"
" stl_c %[new],%[mem]\n"
" beq %[new],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
: [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
: "memory");
smp_mb();
return old;
}
#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
static __inline__ s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
s64 c, new, old;
smp_mb();
__asm__ __volatile__(
"1: ldq_l %[old],%[mem]\n"
" cmpeq %[old],%[u],%[c]\n"
" addq %[old],%[a],%[new]\n"
" bne %[c],2f\n"
" stq_c %[new],%[mem]\n"
" beq %[new],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
: [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
: "memory");
smp_mb();
return old;
}
#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
{
s64 old, tmp;
smp_mb();
__asm__ __volatile__(
"1: ldq_l %[old],%[mem]\n"
" subq %[old],1,%[tmp]\n"
" ble %[old],2f\n"
" stq_c %[tmp],%[mem]\n"
" beq %[tmp],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [tmp] "=&r"(tmp)
: [mem] "m"(*v)
: "memory");
smp_mb();
return old - 1;
}
#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
#endif /* _ALPHA_ATOMIC_H */
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