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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
- #define arch_atomic64_cmpxchg(v, old, new) \
- (arch_cmpxchg(&((v)->counter), old, new))
- #define arch_atomic64_xchg(v, new) \
- (arch_xchg(&((v)->counter), new))
- #define arch_atomic_cmpxchg(v, old, new) \
- (arch_cmpxchg(&((v)->counter), old, new))
- #define arch_atomic_xchg(v, new) \
- (arch_xchg(&((v)->counter), new))
- /**
- * arch_atomic_fetch_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 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
- /**
- * arch_atomic64_fetch_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 the old value of @v.
- */
- 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
- /*
- * arch_atomic64_dec_if_positive - decrement by 1 if old value positive
- * @v: pointer of type atomic_t
- *
- * The function returns the old value of *v minus 1, even if
- * the atomic variable, v, was not decremented.
- */
- 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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