/* $NetBSD: atomic.S,v 1.29.2.1 2024/07/20 16:11:27 martin 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 #include #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 * * Sync with xen_mb in sys/arch/amd64/amd64/cpufunc.S. */ 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)