/* $NetBSD: atomic.S,v 1.36.2.1 2024/07/20 16:11:26 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 /* * __HAVE_ constants should not be in * because we can't use them from assembly. OTOH we * only need __HAVE_ATOMIC64_OPS here, and we don't. */ #ifdef _KERNEL #define ALIAS(f, t) STRONG_ALIAS(f,t) #else #define ALIAS(f, t) WEAK_ALIAS(f,t) #endif #ifdef _HARDKERNEL #include "opt_xen.h" #include #define LOCK HOTPATCH(HP_NAME_NOLOCK, 1); lock #define HOTPATCH_CAS_64 HOTPATCH(HP_NAME_CAS_64, 49); #else #define LOCK lock #define HOTPATCH_CAS_64 /* nothing */ #endif .text ENTRY(_atomic_add_32) movl 4(%esp), %edx movl 8(%esp), %eax LOCK addl %eax, (%edx) ret END(_atomic_add_32) ENTRY(_atomic_add_32_nv) movl 4(%esp), %edx movl 8(%esp), %eax movl %eax, %ecx LOCK xaddl %eax, (%edx) addl %ecx, %eax ret END(_atomic_add_32_nv) ENTRY(_atomic_and_32) movl 4(%esp), %edx movl 8(%esp), %eax LOCK andl %eax, (%edx) ret END(_atomic_and_32) ENTRY(_atomic_and_32_nv) movl 4(%esp), %edx movl (%edx), %eax 0: movl %eax, %ecx andl 8(%esp), %ecx LOCK cmpxchgl %ecx, (%edx) jnz 1f movl %ecx, %eax ret 1: jmp 0b END(_atomic_and_32_nv) ENTRY(_atomic_dec_32) movl 4(%esp), %edx LOCK decl (%edx) ret END(_atomic_dec_32) ENTRY(_atomic_dec_32_nv) movl 4(%esp), %edx movl $-1, %eax LOCK xaddl %eax, (%edx) decl %eax ret END(_atomic_dec_32_nv) ENTRY(_atomic_inc_32) movl 4(%esp), %edx LOCK incl (%edx) ret END(_atomic_inc_32) ENTRY(_atomic_inc_32_nv) movl 4(%esp), %edx movl $1, %eax LOCK xaddl %eax, (%edx) incl %eax ret END(_atomic_inc_32_nv) ENTRY(_atomic_or_32) movl 4(%esp), %edx movl 8(%esp), %eax LOCK orl %eax, (%edx) ret END(_atomic_or_32) ENTRY(_atomic_or_32_nv) movl 4(%esp), %edx movl (%edx), %eax 0: movl %eax, %ecx orl 8(%esp), %ecx LOCK cmpxchgl %ecx, (%edx) jnz 1f movl %ecx, %eax ret 1: jmp 0b END(_atomic_or_32_nv) ENTRY(_atomic_swap_32) movl 4(%esp), %edx movl 8(%esp), %eax xchgl %eax, (%edx) ret END(_atomic_swap_32) ENTRY(_atomic_cas_32) movl 4(%esp), %edx movl 8(%esp), %eax movl 12(%esp), %ecx LOCK cmpxchgl %ecx, (%edx) /* %eax now contains the old value */ ret END(_atomic_cas_32) ENTRY(_atomic_cas_32_ni) movl 4(%esp), %edx movl 8(%esp), %eax movl 12(%esp), %ecx cmpxchgl %ecx, (%edx) /* %eax now contains the old value */ ret END(_atomic_cas_32_ni) 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 ADDL, * 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 ADDL 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/i386/i386/cpufunc.S. */ LOCK addl $0, -4(%esp) ret END(_membar_sync) #if defined(__HAVE_ATOMIC64_OPS) || defined(_KERNEL) #ifdef XENPV STRONG_ALIAS(_atomic_cas_64,_atomic_cas_cx8) #else ENTRY(_atomic_cas_64) HOTPATCH_CAS_64 /* 49 bytes of instructions */ #ifdef _HARDKERNEL pushf cli #endif pushl %edi pushl %ebx movl 12(%esp), %edi movl 16(%esp), %eax movl 20(%esp), %edx movl 24(%esp), %ebx movl 28(%esp), %ecx cmpl 0(%edi), %eax jne 2f cmpl 4(%edi), %edx jne 2f movl %ebx, 0(%edi) movl %ecx, 4(%edi) 1: popl %ebx popl %edi #ifdef _HARDKERNEL popf #endif ret 2: movl 0(%edi), %eax movl 4(%edi), %edx jmp 1b END(_atomic_cas_64) #endif /* !XENPV */ ENTRY(_atomic_cas_cx8) /* 49 bytes of instructions */ pushl %edi pushl %ebx movl 12(%esp), %edi movl 16(%esp), %eax movl 20(%esp), %edx movl 24(%esp), %ebx movl 28(%esp), %ecx LOCK cmpxchg8b (%edi) popl %ebx popl %edi ret #ifdef _HARDKERNEL .space 20, 0xCC #endif END(_atomic_cas_cx8) LABEL(_atomic_cas_cx8_end) #endif /* __HAVE_ATOMIC64_OPS || _KERNEL */ ALIAS(atomic_add_32,_atomic_add_32) ALIAS(atomic_add_int,_atomic_add_32) ALIAS(atomic_add_long,_atomic_add_32) ALIAS(atomic_add_ptr,_atomic_add_32) ALIAS(atomic_add_32_nv,_atomic_add_32_nv) ALIAS(atomic_add_int_nv,_atomic_add_32_nv) ALIAS(atomic_add_long_nv,_atomic_add_32_nv) ALIAS(atomic_add_ptr_nv,_atomic_add_32_nv) ALIAS(atomic_and_32,_atomic_and_32) ALIAS(atomic_and_uint,_atomic_and_32) ALIAS(atomic_and_ulong,_atomic_and_32) ALIAS(atomic_and_ptr,_atomic_and_32) ALIAS(atomic_and_32_nv,_atomic_and_32_nv) ALIAS(atomic_and_uint_nv,_atomic_and_32_nv) ALIAS(atomic_and_ulong_nv,_atomic_and_32_nv) ALIAS(atomic_and_ptr_nv,_atomic_and_32_nv) ALIAS(atomic_dec_32,_atomic_dec_32) ALIAS(atomic_dec_uint,_atomic_dec_32) ALIAS(atomic_dec_ulong,_atomic_dec_32) ALIAS(atomic_dec_ptr,_atomic_dec_32) ALIAS(atomic_dec_32_nv,_atomic_dec_32_nv) ALIAS(atomic_dec_uint_nv,_atomic_dec_32_nv) ALIAS(atomic_dec_ulong_nv,_atomic_dec_32_nv) ALIAS(atomic_dec_ptr_nv,_atomic_dec_32_nv) ALIAS(atomic_inc_32,_atomic_inc_32) ALIAS(atomic_inc_uint,_atomic_inc_32) ALIAS(atomic_inc_ulong,_atomic_inc_32) ALIAS(atomic_inc_ptr,_atomic_inc_32) ALIAS(atomic_inc_32_nv,_atomic_inc_32_nv) ALIAS(atomic_inc_uint_nv,_atomic_inc_32_nv) ALIAS(atomic_inc_ulong_nv,_atomic_inc_32_nv) ALIAS(atomic_inc_ptr_nv,_atomic_inc_32_nv) ALIAS(atomic_or_32,_atomic_or_32) ALIAS(atomic_or_uint,_atomic_or_32) ALIAS(atomic_or_ulong,_atomic_or_32) ALIAS(atomic_or_ptr,_atomic_or_32) ALIAS(atomic_or_32_nv,_atomic_or_32_nv) ALIAS(atomic_or_uint_nv,_atomic_or_32_nv) ALIAS(atomic_or_ulong_nv,_atomic_or_32_nv) ALIAS(atomic_or_ptr_nv,_atomic_or_32_nv) ALIAS(atomic_swap_32,_atomic_swap_32) ALIAS(atomic_swap_uint,_atomic_swap_32) ALIAS(atomic_swap_ulong,_atomic_swap_32) ALIAS(atomic_swap_ptr,_atomic_swap_32) ALIAS(atomic_cas_32,_atomic_cas_32) ALIAS(atomic_cas_uint,_atomic_cas_32) ALIAS(atomic_cas_ulong,_atomic_cas_32) ALIAS(atomic_cas_ptr,_atomic_cas_32) ALIAS(atomic_cas_32_ni,_atomic_cas_32_ni) ALIAS(atomic_cas_uint_ni,_atomic_cas_32_ni) ALIAS(atomic_cas_ulong_ni,_atomic_cas_32_ni) ALIAS(atomic_cas_ptr_ni,_atomic_cas_32_ni) #if defined(__HAVE_ATOMIC64_OPS) || defined(_KERNEL) ALIAS(atomic_cas_64,_atomic_cas_64) ALIAS(atomic_cas_64_ni,_atomic_cas_64) ALIAS(__sync_val_compare_and_swap_8,_atomic_cas_64) #endif /* __HAVE_ATOMIC64_OPS || _KERNEL */ 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_32) STRONG_ALIAS(_atomic_add_ptr,_atomic_add_32) STRONG_ALIAS(_atomic_add_int_nv,_atomic_add_32_nv) STRONG_ALIAS(_atomic_add_long_nv,_atomic_add_32_nv) STRONG_ALIAS(_atomic_add_ptr_nv,_atomic_add_32_nv) STRONG_ALIAS(_atomic_and_uint,_atomic_and_32) STRONG_ALIAS(_atomic_and_ulong,_atomic_and_32) STRONG_ALIAS(_atomic_and_ptr,_atomic_and_32) STRONG_ALIAS(_atomic_and_uint_nv,_atomic_and_32_nv) STRONG_ALIAS(_atomic_and_ulong_nv,_atomic_and_32_nv) STRONG_ALIAS(_atomic_and_ptr_nv,_atomic_and_32_nv) STRONG_ALIAS(_atomic_dec_uint,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_ulong,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_ptr,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_uint_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_dec_ulong_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_dec_ptr_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_inc_uint,_atomic_inc_32) STRONG_ALIAS(_atomic_inc_ulong,_atomic_inc_32) STRONG_ALIAS(_atomic_inc_ptr,_atomic_inc_32) STRONG_ALIAS(_atomic_inc_uint_nv,_atomic_inc_32_nv) STRONG_ALIAS(_atomic_inc_ulong_nv,_atomic_inc_32_nv) STRONG_ALIAS(_atomic_inc_ptr_nv,_atomic_inc_32_nv) STRONG_ALIAS(_atomic_or_uint,_atomic_or_32) STRONG_ALIAS(_atomic_or_ulong,_atomic_or_32) STRONG_ALIAS(_atomic_or_ptr,_atomic_or_32) STRONG_ALIAS(_atomic_or_uint_nv,_atomic_or_32_nv) STRONG_ALIAS(_atomic_or_ulong_nv,_atomic_or_32_nv) STRONG_ALIAS(_atomic_or_ptr_nv,_atomic_or_32_nv) STRONG_ALIAS(_atomic_swap_uint,_atomic_swap_32) STRONG_ALIAS(_atomic_swap_ulong,_atomic_swap_32) STRONG_ALIAS(_atomic_swap_ptr,_atomic_swap_32) STRONG_ALIAS(_atomic_cas_uint,_atomic_cas_32) STRONG_ALIAS(_atomic_cas_ulong,_atomic_cas_32) STRONG_ALIAS(_atomic_cas_ptr,_atomic_cas_32) STRONG_ALIAS(_atomic_cas_uint_ni,_atomic_cas_32_ni) STRONG_ALIAS(_atomic_cas_ulong_ni,_atomic_cas_32_ni) STRONG_ALIAS(_atomic_cas_ptr_ni,_atomic_cas_32_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)