linux/arch/arm64/include/asm/atomic_lse.h
Will Deacon b4f9209bfc arm64: Avoid masking "old" for LSE cmpxchg() implementation
The CAS instructions implicitly access only the relevant bits of the "old"
argument, so there is no need for explicit masking via type-casting as
there is in the LL/SC implementation.

Move the casting into the LL/SC code and remove it altogether for the LSE
implementation.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-07 17:28:01 +00:00

535 lines
15 KiB
C

/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_ATOMIC_LSE_H
#define __ASM_ATOMIC_LSE_H
#ifndef __ARM64_IN_ATOMIC_IMPL
#error "please don't include this file directly"
#endif
#define __LL_SC_ATOMIC(op) __LL_SC_CALL(atomic_##op)
#define ATOMIC_OP(op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(op), \
" " #asm_op " %w[i], %[v]\n") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS); \
}
ATOMIC_OP(andnot, stclr)
ATOMIC_OP(or, stset)
ATOMIC_OP(xor, steor)
ATOMIC_OP(add, stadd)
#undef ATOMIC_OP
#define ATOMIC_FETCH_OP(name, mb, op, asm_op, cl...) \
static inline int atomic_fetch_##op##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_##op##name), \
/* LSE atomics */ \
" " #asm_op #mb " %w[i], %w[i], %[v]") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
#define ATOMIC_FETCH_OPS(op, asm_op) \
ATOMIC_FETCH_OP(_relaxed, , op, asm_op) \
ATOMIC_FETCH_OP(_acquire, a, op, asm_op, "memory") \
ATOMIC_FETCH_OP(_release, l, op, asm_op, "memory") \
ATOMIC_FETCH_OP( , al, op, asm_op, "memory")
ATOMIC_FETCH_OPS(andnot, ldclr)
ATOMIC_FETCH_OPS(or, ldset)
ATOMIC_FETCH_OPS(xor, ldeor)
ATOMIC_FETCH_OPS(add, ldadd)
#undef ATOMIC_FETCH_OP
#undef ATOMIC_FETCH_OPS
#define ATOMIC_OP_ADD_RETURN(name, mb, cl...) \
static inline int atomic_add_return##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(add_return##name) \
__nops(1), \
/* LSE atomics */ \
" ldadd" #mb " %w[i], w30, %[v]\n" \
" add %w[i], %w[i], w30") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
ATOMIC_OP_ADD_RETURN(_relaxed, )
ATOMIC_OP_ADD_RETURN(_acquire, a, "memory")
ATOMIC_OP_ADD_RETURN(_release, l, "memory")
ATOMIC_OP_ADD_RETURN( , al, "memory")
#undef ATOMIC_OP_ADD_RETURN
static inline void atomic_and(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC(and)
__nops(1),
/* LSE atomics */
" mvn %w[i], %w[i]\n"
" stclr %w[i], %[v]")
: [i] "+&r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: __LL_SC_CLOBBERS);
}
#define ATOMIC_FETCH_OP_AND(name, mb, cl...) \
static inline int atomic_fetch_and##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_and##name) \
__nops(1), \
/* LSE atomics */ \
" mvn %w[i], %w[i]\n" \
" ldclr" #mb " %w[i], %w[i], %[v]") \
: [i] "+&r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
ATOMIC_FETCH_OP_AND(_relaxed, )
ATOMIC_FETCH_OP_AND(_acquire, a, "memory")
ATOMIC_FETCH_OP_AND(_release, l, "memory")
ATOMIC_FETCH_OP_AND( , al, "memory")
#undef ATOMIC_FETCH_OP_AND
static inline void atomic_sub(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC(sub)
__nops(1),
/* LSE atomics */
" neg %w[i], %w[i]\n"
" stadd %w[i], %[v]")
: [i] "+&r" (w0), [v] "+Q" (v->counter)
: "r" (x1)
: __LL_SC_CLOBBERS);
}
#define ATOMIC_OP_SUB_RETURN(name, mb, cl...) \
static inline int atomic_sub_return##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(sub_return##name) \
__nops(2), \
/* LSE atomics */ \
" neg %w[i], %w[i]\n" \
" ldadd" #mb " %w[i], w30, %[v]\n" \
" add %w[i], %w[i], w30") \
: [i] "+&r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS , ##cl); \
\
return w0; \
}
ATOMIC_OP_SUB_RETURN(_relaxed, )
ATOMIC_OP_SUB_RETURN(_acquire, a, "memory")
ATOMIC_OP_SUB_RETURN(_release, l, "memory")
ATOMIC_OP_SUB_RETURN( , al, "memory")
#undef ATOMIC_OP_SUB_RETURN
#define ATOMIC_FETCH_OP_SUB(name, mb, cl...) \
static inline int atomic_fetch_sub##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_sub##name) \
__nops(1), \
/* LSE atomics */ \
" neg %w[i], %w[i]\n" \
" ldadd" #mb " %w[i], %w[i], %[v]") \
: [i] "+&r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
ATOMIC_FETCH_OP_SUB(_relaxed, )
ATOMIC_FETCH_OP_SUB(_acquire, a, "memory")
ATOMIC_FETCH_OP_SUB(_release, l, "memory")
ATOMIC_FETCH_OP_SUB( , al, "memory")
#undef ATOMIC_FETCH_OP_SUB
#undef __LL_SC_ATOMIC
#define __LL_SC_ATOMIC64(op) __LL_SC_CALL(atomic64_##op)
#define ATOMIC64_OP(op, asm_op) \
static inline void atomic64_##op(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(op), \
" " #asm_op " %[i], %[v]\n") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS); \
}
ATOMIC64_OP(andnot, stclr)
ATOMIC64_OP(or, stset)
ATOMIC64_OP(xor, steor)
ATOMIC64_OP(add, stadd)
#undef ATOMIC64_OP
#define ATOMIC64_FETCH_OP(name, mb, op, asm_op, cl...) \
static inline long atomic64_fetch_##op##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_##op##name), \
/* LSE atomics */ \
" " #asm_op #mb " %[i], %[i], %[v]") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
#define ATOMIC64_FETCH_OPS(op, asm_op) \
ATOMIC64_FETCH_OP(_relaxed, , op, asm_op) \
ATOMIC64_FETCH_OP(_acquire, a, op, asm_op, "memory") \
ATOMIC64_FETCH_OP(_release, l, op, asm_op, "memory") \
ATOMIC64_FETCH_OP( , al, op, asm_op, "memory")
ATOMIC64_FETCH_OPS(andnot, ldclr)
ATOMIC64_FETCH_OPS(or, ldset)
ATOMIC64_FETCH_OPS(xor, ldeor)
ATOMIC64_FETCH_OPS(add, ldadd)
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_FETCH_OPS
#define ATOMIC64_OP_ADD_RETURN(name, mb, cl...) \
static inline long atomic64_add_return##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(add_return##name) \
__nops(1), \
/* LSE atomics */ \
" ldadd" #mb " %[i], x30, %[v]\n" \
" add %[i], %[i], x30") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_OP_ADD_RETURN(_relaxed, )
ATOMIC64_OP_ADD_RETURN(_acquire, a, "memory")
ATOMIC64_OP_ADD_RETURN(_release, l, "memory")
ATOMIC64_OP_ADD_RETURN( , al, "memory")
#undef ATOMIC64_OP_ADD_RETURN
static inline void atomic64_and(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(and)
__nops(1),
/* LSE atomics */
" mvn %[i], %[i]\n"
" stclr %[i], %[v]")
: [i] "+&r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: __LL_SC_CLOBBERS);
}
#define ATOMIC64_FETCH_OP_AND(name, mb, cl...) \
static inline long atomic64_fetch_and##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_and##name) \
__nops(1), \
/* LSE atomics */ \
" mvn %[i], %[i]\n" \
" ldclr" #mb " %[i], %[i], %[v]") \
: [i] "+&r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_FETCH_OP_AND(_relaxed, )
ATOMIC64_FETCH_OP_AND(_acquire, a, "memory")
ATOMIC64_FETCH_OP_AND(_release, l, "memory")
ATOMIC64_FETCH_OP_AND( , al, "memory")
#undef ATOMIC64_FETCH_OP_AND
static inline void atomic64_sub(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(sub)
__nops(1),
/* LSE atomics */
" neg %[i], %[i]\n"
" stadd %[i], %[v]")
: [i] "+&r" (x0), [v] "+Q" (v->counter)
: "r" (x1)
: __LL_SC_CLOBBERS);
}
#define ATOMIC64_OP_SUB_RETURN(name, mb, cl...) \
static inline long atomic64_sub_return##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(sub_return##name) \
__nops(2), \
/* LSE atomics */ \
" neg %[i], %[i]\n" \
" ldadd" #mb " %[i], x30, %[v]\n" \
" add %[i], %[i], x30") \
: [i] "+&r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_OP_SUB_RETURN(_relaxed, )
ATOMIC64_OP_SUB_RETURN(_acquire, a, "memory")
ATOMIC64_OP_SUB_RETURN(_release, l, "memory")
ATOMIC64_OP_SUB_RETURN( , al, "memory")
#undef ATOMIC64_OP_SUB_RETURN
#define ATOMIC64_FETCH_OP_SUB(name, mb, cl...) \
static inline long atomic64_fetch_sub##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_sub##name) \
__nops(1), \
/* LSE atomics */ \
" neg %[i], %[i]\n" \
" ldadd" #mb " %[i], %[i], %[v]") \
: [i] "+&r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_FETCH_OP_SUB(_relaxed, )
ATOMIC64_FETCH_OP_SUB(_acquire, a, "memory")
ATOMIC64_FETCH_OP_SUB(_release, l, "memory")
ATOMIC64_FETCH_OP_SUB( , al, "memory")
#undef ATOMIC64_FETCH_OP_SUB
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
register long x0 asm ("x0") = (long)v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(dec_if_positive)
__nops(6),
/* LSE atomics */
"1: ldr x30, %[v]\n"
" subs %[ret], x30, #1\n"
" b.lt 2f\n"
" casal x30, %[ret], %[v]\n"
" sub x30, x30, #1\n"
" sub x30, x30, %[ret]\n"
" cbnz x30, 1b\n"
"2:")
: [ret] "+&r" (x0), [v] "+Q" (v->counter)
:
: __LL_SC_CLOBBERS, "cc", "memory");
return x0;
}
#undef __LL_SC_ATOMIC64
#define __LL_SC_CMPXCHG(op) __LL_SC_CALL(__cmpxchg_case_##op)
#define __CMPXCHG_CASE(w, sfx, name, sz, mb, cl...) \
static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr, \
u##sz old, \
u##sz new) \
{ \
register unsigned long x0 asm ("x0") = (unsigned long)ptr; \
register u##sz x1 asm ("x1") = old; \
register u##sz x2 asm ("x2") = new; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_CMPXCHG(name##sz) \
__nops(2), \
/* LSE atomics */ \
" mov " #w "30, %" #w "[old]\n" \
" cas" #mb #sfx "\t" #w "30, %" #w "[new], %[v]\n" \
" mov %" #w "[ret], " #w "30") \
: [ret] "+r" (x0), [v] "+Q" (*(unsigned long *)ptr) \
: [old] "r" (x1), [new] "r" (x2) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
__CMPXCHG_CASE(w, b, , 8, )
__CMPXCHG_CASE(w, h, , 16, )
__CMPXCHG_CASE(w, , , 32, )
__CMPXCHG_CASE(x, , , 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(x, , 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(x, , rel_, 64, l, "memory")
__CMPXCHG_CASE(w, b, mb_, 8, al, "memory")
__CMPXCHG_CASE(w, h, mb_, 16, al, "memory")
__CMPXCHG_CASE(w, , mb_, 32, al, "memory")
__CMPXCHG_CASE(x, , mb_, 64, al, "memory")
#undef __LL_SC_CMPXCHG
#undef __CMPXCHG_CASE
#define __LL_SC_CMPXCHG_DBL(op) __LL_SC_CALL(__cmpxchg_double##op)
#define __CMPXCHG_DBL(name, mb, cl...) \
static inline long __cmpxchg_double##name(unsigned long old1, \
unsigned long old2, \
unsigned long new1, \
unsigned long new2, \
volatile void *ptr) \
{ \
unsigned long oldval1 = old1; \
unsigned long oldval2 = old2; \
register unsigned long x0 asm ("x0") = old1; \
register unsigned long x1 asm ("x1") = old2; \
register unsigned long x2 asm ("x2") = new1; \
register unsigned long x3 asm ("x3") = new2; \
register unsigned long x4 asm ("x4") = (unsigned long)ptr; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_CMPXCHG_DBL(name) \
__nops(3), \
/* LSE atomics */ \
" casp" #mb "\t%[old1], %[old2], %[new1], %[new2], %[v]\n"\
" eor %[old1], %[old1], %[oldval1]\n" \
" eor %[old2], %[old2], %[oldval2]\n" \
" orr %[old1], %[old1], %[old2]") \
: [old1] "+&r" (x0), [old2] "+&r" (x1), \
[v] "+Q" (*(unsigned long *)ptr) \
: [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \
[oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
__CMPXCHG_DBL( , )
__CMPXCHG_DBL(_mb, al, "memory")
#undef __LL_SC_CMPXCHG_DBL
#undef __CMPXCHG_DBL
#endif /* __ASM_ATOMIC_LSE_H */