/* $NetBSD: atomic.S,v 1.29 2022/07/30 14:11:00 riastradh Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe, and by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/param.h>
#include <machine/asm.h>
#ifdef _KERNEL
#define ALIAS(f, t) STRONG_ALIAS(f,t)
#else
#define ALIAS(f, t) WEAK_ALIAS(f,t)
#endif
.text
/* 32-bit */
ENTRY(_atomic_add_32)
LOCK
addl %esi, (%rdi)
ret
END(_atomic_add_32)
ENTRY(_atomic_add_32_nv)
movl %esi, %eax
LOCK
xaddl %eax, (%rdi)
addl %esi, %eax
ret
END(_atomic_add_32_nv)
ENTRY(_atomic_and_32)
LOCK
andl %esi, (%rdi)
ret
END(_atomic_and_32)
ENTRY(_atomic_and_32_nv)
movl (%rdi), %eax
1:
movl %eax, %ecx
andl %esi, %ecx
LOCK
cmpxchgl %ecx, (%rdi)
jnz 1b
movl %ecx, %eax
ret
END(_atomic_and_32_nv)
ENTRY(_atomic_dec_32)
LOCK
decl (%rdi)
ret
END(_atomic_dec_32)
ENTRY(_atomic_dec_32_nv)
movl $-1, %eax
LOCK
xaddl %eax, (%rdi)
decl %eax
ret
END(_atomic_dec_32_nv)
ENTRY(_atomic_inc_32)
LOCK
incl (%rdi)
ret
END(_atomic_inc_32)
ENTRY(_atomic_inc_32_nv)
movl $1, %eax
LOCK
xaddl %eax, (%rdi)
incl %eax
ret
END(_atomic_inc_32_nv)
ENTRY(_atomic_or_32)
LOCK
orl %esi, (%rdi)
ret
END(_atomic_or_32)
ENTRY(_atomic_or_32_nv)
movl (%rdi), %eax
1:
movl %eax, %ecx
orl %esi, %ecx
LOCK
cmpxchgl %ecx, (%rdi)
jnz 1b
movl %ecx, %eax
ret
END(_atomic_or_32_nv)
ENTRY(_atomic_swap_32)
movl %esi, %eax
xchgl %eax, (%rdi)
ret
END(_atomic_swap_32)
ENTRY(_atomic_cas_32)
movl %esi, %eax
LOCK
cmpxchgl %edx, (%rdi)
/* %eax now contains the old value */
ret
END(_atomic_cas_32)
ENTRY(_atomic_cas_32_ni)
movl %esi, %eax
cmpxchgl %edx, (%rdi)
/* %eax now contains the old value */
ret
END(_atomic_cas_32_ni)
/* 64-bit */
ENTRY(_atomic_add_64)
LOCK
addq %rsi, (%rdi)
ret
END(_atomic_add_64)
ENTRY(_atomic_add_64_nv)
movq %rsi, %rax
LOCK
xaddq %rax, (%rdi)
addq %rsi, %rax
ret
END(_atomic_add_64_nv)
ENTRY(_atomic_and_64)
LOCK
andq %rsi, (%rdi)
ret
END(_atomic_and_64)
ENTRY(_atomic_and_64_nv)
movq (%rdi), %rax
1:
movq %rax, %rcx
andq %rsi, %rcx
LOCK
cmpxchgq %rcx, (%rdi)
jnz 1b
movq %rcx, %rax
ret
END(_atomic_and_64_nv)
ENTRY(_atomic_dec_64)
LOCK
decq (%rdi)
ret
END(_atomic_dec_64)
ENTRY(_atomic_dec_64_nv)
movq $-1, %rax
LOCK
xaddq %rax, (%rdi)
decq %rax
ret
END(_atomic_dec_64_nv)
ENTRY(_atomic_inc_64)
LOCK
incq (%rdi)
ret
END(_atomic_inc_64)
ENTRY(_atomic_inc_64_nv)
movq $1, %rax
LOCK
xaddq %rax, (%rdi)
incq %rax
ret
END(_atomic_inc_64_nv)
ENTRY(_atomic_or_64)
LOCK
orq %rsi, (%rdi)
ret
END(_atomic_or_64)
ENTRY(_atomic_or_64_nv)
movq (%rdi), %rax
1:
movq %rax, %rcx
orq %rsi, %rcx
LOCK
cmpxchgq %rcx, (%rdi)
jnz 1b
movq %rcx, %rax
ret
END(_atomic_or_64_nv)
ENTRY(_atomic_swap_64)
movq %rsi, %rax
xchgq %rax, (%rdi)
ret
END(_atomic_swap_64)
ENTRY(_atomic_cas_64)
movq %rsi, %rax
LOCK
cmpxchgq %rdx, (%rdi)
/* %eax now contains the old value */
ret
END(_atomic_cas_64)
ENTRY(_atomic_cas_64_ni)
movq %rsi, %rax
cmpxchgq %rdx, (%rdi)
/* %eax now contains the old value */
ret
END(_atomic_cas_64_ni)
/* memory barriers */
ENTRY(_membar_acquire)
/*
* Every load from normal memory is a load-acquire on x86, so
* there is never any need for explicit barriers to order
* load-before-anything.
*/
ret
END(_membar_acquire)
ENTRY(_membar_release)
/*
* Every store to normal memory is a store-release on x86, so
* there is never any need for explicit barriers to order
* anything-before-store.
*/
ret
END(_membar_release)
ENTRY(_membar_sync)
/*
* MFENCE, or a serializing instruction like a locked ADDQ,
* is necessary to order store-before-load. Every other
* ordering -- load-before-anything, anything-before-store --
* is already guaranteed without explicit barriers.
*
* Empirically it turns out locked ADDQ is cheaper than MFENCE,
* so we use that, with an offset below the return address on
* the stack to avoid a false dependency with RET. (It might
* even be better to use a much lower offset, say -128, to
* avoid false dependencies for subsequent callees of the
* caller.)
*
* https://pvk.ca/Blog/2014/10/19/performance-optimisation-~-writing-an-essay/
* https://shipilev.net/blog/2014/on-the-fence-with-dependencies/
* https://www.agner.org/optimize/instruction_tables.pdf
*/
LOCK
addq $0, -8(%rsp)
ret
END(_membar_sync)
ALIAS(atomic_add_32,_atomic_add_32)
ALIAS(atomic_add_64,_atomic_add_64)
ALIAS(atomic_add_int,_atomic_add_32)
ALIAS(atomic_add_long,_atomic_add_64)
ALIAS(atomic_add_ptr,_atomic_add_64)
ALIAS(atomic_add_32_nv,_atomic_add_32_nv)
ALIAS(atomic_add_64_nv,_atomic_add_64_nv)
ALIAS(atomic_add_int_nv,_atomic_add_32_nv)
ALIAS(atomic_add_long_nv,_atomic_add_64_nv)
ALIAS(atomic_add_ptr_nv,_atomic_add_64_nv)
ALIAS(atomic_and_32,_atomic_and_32)
ALIAS(atomic_and_64,_atomic_and_64)
ALIAS(atomic_and_uint,_atomic_and_32)
ALIAS(atomic_and_ulong,_atomic_and_64)
ALIAS(atomic_and_ptr,_atomic_and_64)
ALIAS(atomic_and_32_nv,_atomic_and_32_nv)
ALIAS(atomic_and_64_nv,_atomic_and_64_nv)
ALIAS(atomic_and_uint_nv,_atomic_and_32_nv)
ALIAS(atomic_and_ulong_nv,_atomic_and_64_nv)
ALIAS(atomic_and_ptr_nv,_atomic_and_64_nv)
ALIAS(atomic_dec_32,_atomic_dec_32)
ALIAS(atomic_dec_64,_atomic_dec_64)
ALIAS(atomic_dec_uint,_atomic_dec_32)
ALIAS(atomic_dec_ulong,_atomic_dec_64)
ALIAS(atomic_dec_ptr,_atomic_dec_64)
ALIAS(atomic_dec_32_nv,_atomic_dec_32_nv)
ALIAS(atomic_dec_64_nv,_atomic_dec_64_nv)
ALIAS(atomic_dec_uint_nv,_atomic_dec_32_nv)
ALIAS(atomic_dec_ulong_nv,_atomic_dec_64_nv)
ALIAS(atomic_dec_ptr_nv,_atomic_dec_64_nv)
ALIAS(atomic_inc_32,_atomic_inc_32)
ALIAS(atomic_inc_64,_atomic_inc_64)
ALIAS(atomic_inc_uint,_atomic_inc_32)
ALIAS(atomic_inc_ulong,_atomic_inc_64)
ALIAS(atomic_inc_ptr,_atomic_inc_64)
ALIAS(atomic_inc_32_nv,_atomic_inc_32_nv)
ALIAS(atomic_inc_64_nv,_atomic_inc_64_nv)
ALIAS(atomic_inc_uint_nv,_atomic_inc_32_nv)
ALIAS(atomic_inc_ulong_nv,_atomic_inc_64_nv)
ALIAS(atomic_inc_ptr_nv,_atomic_inc_64_nv)
ALIAS(atomic_or_32,_atomic_or_32)
ALIAS(atomic_or_64,_atomic_or_64)
ALIAS(atomic_or_uint,_atomic_or_32)
ALIAS(atomic_or_ulong,_atomic_or_64)
ALIAS(atomic_or_ptr,_atomic_or_64)
ALIAS(atomic_or_32_nv,_atomic_or_32_nv)
ALIAS(atomic_or_64_nv,_atomic_or_64_nv)
ALIAS(atomic_or_uint_nv,_atomic_or_32_nv)
ALIAS(atomic_or_ulong_nv,_atomic_or_64_nv)
ALIAS(atomic_or_ptr_nv,_atomic_or_64_nv)
ALIAS(atomic_swap_32,_atomic_swap_32)
ALIAS(atomic_swap_64,_atomic_swap_64)
ALIAS(atomic_swap_uint,_atomic_swap_32)
ALIAS(atomic_swap_ulong,_atomic_swap_64)
ALIAS(atomic_swap_ptr,_atomic_swap_64)
ALIAS(atomic_cas_32,_atomic_cas_32)
ALIAS(atomic_cas_64,_atomic_cas_64)
ALIAS(atomic_cas_uint,_atomic_cas_32)
ALIAS(atomic_cas_ulong,_atomic_cas_64)
ALIAS(atomic_cas_ptr,_atomic_cas_64)
ALIAS(atomic_cas_32_ni,_atomic_cas_32_ni)
ALIAS(atomic_cas_64_ni,_atomic_cas_64_ni)
ALIAS(atomic_cas_uint_ni,_atomic_cas_32_ni)
ALIAS(atomic_cas_ulong_ni,_atomic_cas_64_ni)
ALIAS(atomic_cas_ptr_ni,_atomic_cas_64_ni)
ALIAS(membar_acquire,_membar_acquire)
ALIAS(membar_release,_membar_release)
ALIAS(membar_sync,_membar_sync)
ALIAS(membar_consumer,_membar_acquire)
ALIAS(membar_producer,_membar_release)
ALIAS(membar_enter,_membar_sync)
ALIAS(membar_exit,_membar_release)
ALIAS(membar_sync,_membar_sync)
STRONG_ALIAS(_atomic_add_int,_atomic_add_32)
STRONG_ALIAS(_atomic_add_long,_atomic_add_64)
STRONG_ALIAS(_atomic_add_ptr,_atomic_add_64)
STRONG_ALIAS(_atomic_add_int_nv,_atomic_add_32_nv)
STRONG_ALIAS(_atomic_add_long_nv,_atomic_add_64_nv)
STRONG_ALIAS(_atomic_add_ptr_nv,_atomic_add_64_nv)
STRONG_ALIAS(_atomic_and_uint,_atomic_and_32)
STRONG_ALIAS(_atomic_and_ulong,_atomic_and_64)
STRONG_ALIAS(_atomic_and_ptr,_atomic_and_64)
STRONG_ALIAS(_atomic_and_uint_nv,_atomic_and_32_nv)
STRONG_ALIAS(_atomic_and_ulong_nv,_atomic_and_64_nv)
STRONG_ALIAS(_atomic_and_ptr_nv,_atomic_and_64_nv)
STRONG_ALIAS(_atomic_dec_uint,_atomic_dec_32)
STRONG_ALIAS(_atomic_dec_ulong,_atomic_dec_64)
STRONG_ALIAS(_atomic_dec_ptr,_atomic_dec_64)
STRONG_ALIAS(_atomic_dec_uint_nv,_atomic_dec_32_nv)
STRONG_ALIAS(_atomic_dec_ulong_nv,_atomic_dec_64_nv)
STRONG_ALIAS(_atomic_dec_ptr_nv,_atomic_dec_64_nv)
STRONG_ALIAS(_atomic_inc_uint,_atomic_inc_32)
STRONG_ALIAS(_atomic_inc_ulong,_atomic_inc_64)
STRONG_ALIAS(_atomic_inc_ptr,_atomic_inc_64)
STRONG_ALIAS(_atomic_inc_uint_nv,_atomic_inc_32_nv)
STRONG_ALIAS(_atomic_inc_ulong_nv,_atomic_inc_64_nv)
STRONG_ALIAS(_atomic_inc_ptr_nv,_atomic_inc_64_nv)
STRONG_ALIAS(_atomic_or_uint,_atomic_or_32)
STRONG_ALIAS(_atomic_or_ulong,_atomic_or_64)
STRONG_ALIAS(_atomic_or_ptr,_atomic_or_64)
STRONG_ALIAS(_atomic_or_uint_nv,_atomic_or_32_nv)
STRONG_ALIAS(_atomic_or_ulong_nv,_atomic_or_64_nv)
STRONG_ALIAS(_atomic_or_ptr_nv,_atomic_or_64_nv)
STRONG_ALIAS(_atomic_swap_uint,_atomic_swap_32)
STRONG_ALIAS(_atomic_swap_ulong,_atomic_swap_64)
STRONG_ALIAS(_atomic_swap_ptr,_atomic_swap_64)
STRONG_ALIAS(_atomic_cas_uint,_atomic_cas_32)
STRONG_ALIAS(_atomic_cas_ulong,_atomic_cas_64)
STRONG_ALIAS(_atomic_cas_ptr,_atomic_cas_64)
STRONG_ALIAS(_atomic_cas_uint_ni,_atomic_cas_32_ni)
STRONG_ALIAS(_atomic_cas_ulong_ni,_atomic_cas_64_ni)
STRONG_ALIAS(_atomic_cas_ptr_ni,_atomic_cas_64_ni)
STRONG_ALIAS(_membar_consumer,_membar_acquire)
STRONG_ALIAS(_membar_producer,_membar_release)
STRONG_ALIAS(_membar_enter,_membar_sync)
STRONG_ALIAS(_membar_exit,_membar_release)