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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/atomic.h
*
* Copyright (C) 1996 Russell King.
* Copyright (C) 2002 Deep Blue Solutions Ltd.
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_ATOMIC_LL_SC_H
#define __ASM_ATOMIC_LL_SC_H
#ifndef __ARM64_IN_ATOMIC_IMPL
#error "please don't include this file directly"
#endif
/*
* AArch64 UP and SMP safe atomic ops. We use load exclusive and
* store exclusive to ensure that these are atomic. We may loop
* to ensure that the update happens.
*
* NOTE: these functions do *not* follow the PCS and must explicitly
* save any clobbered registers other than x0 (regardless of return
* value). This is achieved through -fcall-saved-* compiler flags for
* this file, which unfortunately don't work on a per-function basis
* (the optimize attribute silently ignores these options).
*/
#define ATOMIC_OP(op, asm_op) \
__LL_SC_INLINE void \
__LL_SC_PREFIX(arch_atomic_##op(int i, atomic_t *v)) \
{ \
unsigned long tmp; \
int result; \
\
asm volatile("// atomic_" #op "\n" \
" prfm pstl1strm, %2\n" \
"1: ldxr %w0, %2\n" \
" " #asm_op " %w0, %w0, %w3\n" \
" stxr %w1, %w0, %2\n" \
" cbnz %w1, 1b" \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i)); \
} \
__LL_SC_EXPORT(arch_atomic_##op);
#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
__LL_SC_INLINE int \
__LL_SC_PREFIX(arch_atomic_##op##_return##name(int i, atomic_t *v)) \
{ \
unsigned long tmp; \
int result; \
\
asm volatile("// atomic_" #op "_return" #name "\n" \
" prfm pstl1strm, %2\n" \
"1: ld" #acq "xr %w0, %2\n" \
" " #asm_op " %w0, %w0, %w3\n" \
" st" #rel "xr %w1, %w0, %2\n" \
" cbnz %w1, 1b\n" \
" " #mb \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i) \
: cl); \
\
return result; \
} \
__LL_SC_EXPORT(arch_atomic_##op##_return##name);
#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
__LL_SC_INLINE int \
__LL_SC_PREFIX(arch_atomic_fetch_##op##name(int i, atomic_t *v)) \
{ \
unsigned long tmp; \
int val, result; \
\
asm volatile("// atomic_fetch_" #op #name "\n" \
" prfm pstl1strm, %3\n" \
"1: ld" #acq "xr %w0, %3\n" \
" " #asm_op " %w1, %w0, %w4\n" \
" st" #rel "xr %w2, %w1, %3\n" \
" cbnz %w2, 1b\n" \
" " #mb \
: "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i) \
: cl); \
\
return result; \
} \
__LL_SC_EXPORT(arch_atomic_fetch_##op##name);
#define ATOMIC_OPS(...) \
ATOMIC_OP(__VA_ARGS__) \
ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)\
ATOMIC_OP_RETURN(_relaxed, , , , , __VA_ARGS__)\
ATOMIC_OP_RETURN(_acquire, , a, , "memory", __VA_ARGS__)\
ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
ATOMIC_OPS(add, add)
ATOMIC_OPS(sub, sub)
#undef ATOMIC_OPS
#define ATOMIC_OPS(...) \
ATOMIC_OP(__VA_ARGS__) \
ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
ATOMIC_OPS(and, and)
ATOMIC_OPS(andnot, bic)
ATOMIC_OPS(or, orr)
ATOMIC_OPS(xor, eor)
#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#define ATOMIC64_OP(op, asm_op) \
__LL_SC_INLINE void \
__LL_SC_PREFIX(arch_atomic64_##op(s64 i, atomic64_t *v)) \
{ \
s64 result; \
unsigned long tmp; \
\
asm volatile("// atomic64_" #op "\n" \
" prfm pstl1strm, %2\n" \
"1: ldxr %0, %2\n" \
" " #asm_op " %0, %0, %3\n" \
" stxr %w1, %0, %2\n" \
" cbnz %w1, 1b" \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i)); \
} \
__LL_SC_EXPORT(arch_atomic64_##op);
#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
__LL_SC_INLINE s64 \
__LL_SC_PREFIX(arch_atomic64_##op##_return##name(s64 i, atomic64_t *v))\
{ \
s64 result; \
unsigned long tmp; \
\
asm volatile("// atomic64_" #op "_return" #name "\n" \
" prfm pstl1strm, %2\n" \
"1: ld" #acq "xr %0, %2\n" \
" " #asm_op " %0, %0, %3\n" \
" st" #rel "xr %w1, %0, %2\n" \
" cbnz %w1, 1b\n" \
" " #mb \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i) \
: cl); \
\
return result; \
} \
__LL_SC_EXPORT(arch_atomic64_##op##_return##name);
#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
__LL_SC_INLINE s64 \
__LL_SC_PREFIX(arch_atomic64_fetch_##op##name(s64 i, atomic64_t *v)) \
{ \
s64 result, val; \
unsigned long tmp; \
\
asm volatile("// atomic64_fetch_" #op #name "\n" \
" prfm pstl1strm, %3\n" \
"1: ld" #acq "xr %0, %3\n" \
" " #asm_op " %1, %0, %4\n" \
" st" #rel "xr %w2, %1, %3\n" \
" cbnz %w2, 1b\n" \
" " #mb \
: "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
: "Ir" (i) \
: cl); \
\
return result; \
} \
__LL_SC_EXPORT(arch_atomic64_fetch_##op##name);
#define ATOMIC64_OPS(...) \
ATOMIC64_OP(__VA_ARGS__) \
ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__) \
ATOMIC64_OP_RETURN(_relaxed,, , , , __VA_ARGS__) \
ATOMIC64_OP_RETURN(_acquire,, a, , "memory", __VA_ARGS__) \
ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
ATOMIC64_OPS(add, add)
ATOMIC64_OPS(sub, sub)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(...) \
ATOMIC64_OP(__VA_ARGS__) \
ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
ATOMIC64_OPS(and, and)
ATOMIC64_OPS(andnot, bic)
ATOMIC64_OPS(or, orr)
ATOMIC64_OPS(xor, eor)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
__LL_SC_INLINE s64
__LL_SC_PREFIX(arch_atomic64_dec_if_positive(atomic64_t *v))
{
s64 result;
unsigned long tmp;
asm volatile("// atomic64_dec_if_positive\n"
" prfm pstl1strm, %2\n"
"1: ldxr %0, %2\n"
" subs %0, %0, #1\n"
" b.lt 2f\n"
" stlxr %w1, %0, %2\n"
" cbnz %w1, 1b\n"
" dmb ish\n"
"2:"
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
:
: "cc", "memory");
return result;
}
__LL_SC_EXPORT(arch_atomic64_dec_if_positive);
#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl) \
__LL_SC_INLINE u##sz \
__LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \
unsigned long old, \
u##sz new)) \
{ \
unsigned long tmp; \
u##sz oldval; \
\
/* \
* Sub-word sizes require explicit casting so that the compare \
* part of the cmpxchg doesn't end up interpreting non-zero \
* upper bits of the register containing "old". \
*/ \
if (sz < 32) \
old = (u##sz)old; \
\
asm volatile( \
" prfm pstl1strm, %[v]\n" \
"1: ld" #acq "xr" #sfx "\t%" #w "[oldval], %[v]\n" \
" eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \
" cbnz %" #w "[tmp], 2f\n" \
" st" #rel "xr" #sfx "\t%w[tmp], %" #w "[new], %[v]\n" \
" cbnz %w[tmp], 1b\n" \
" " #mb "\n" \
"2:" \
: [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \
[v] "+Q" (*(u##sz *)ptr) \
: [old] "Kr" (old), [new] "r" (new) \
: cl); \
\
return oldval; \
} \
__LL_SC_EXPORT(__cmpxchg_case_##name##sz);
__CMPXCHG_CASE(w, b, , 8, , , , )
__CMPXCHG_CASE(w, h, , 16, , , , )
__CMPXCHG_CASE(w, , , 32, , , , )
__CMPXCHG_CASE( , , , 64, , , , )
__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory")
__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory")
__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory")
__CMPXCHG_CASE( , , acq_, 64, , a, , "memory")
__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory")
__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory")
__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory")
__CMPXCHG_CASE( , , rel_, 64, , , l, "memory")
__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory")
__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory")
__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory")
__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory")
#undef __CMPXCHG_CASE
#define __CMPXCHG_DBL(name, mb, rel, cl) \
__LL_SC_INLINE long \
__LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \
unsigned long old2, \
unsigned long new1, \
unsigned long new2, \
volatile void *ptr)) \
{ \
unsigned long tmp, ret; \
\
asm volatile("// __cmpxchg_double" #name "\n" \
" prfm pstl1strm, %2\n" \
"1: ldxp %0, %1, %2\n" \
" eor %0, %0, %3\n" \
" eor %1, %1, %4\n" \
" orr %1, %0, %1\n" \
" cbnz %1, 2f\n" \
" st" #rel "xp %w0, %5, %6, %2\n" \
" cbnz %w0, 1b\n" \
" " #mb "\n" \
"2:" \
: "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \
: "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
: cl); \
\
return ret; \
} \
__LL_SC_EXPORT(__cmpxchg_double##name);
__CMPXCHG_DBL( , , , )
__CMPXCHG_DBL(_mb, dmb ish, l, "memory")
#undef __CMPXCHG_DBL
#endif /* __ASM_ATOMIC_LL_SC_H */
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