diff options
Diffstat (limited to 'lib/isc/x86_64/include/isc/atomic.h')
-rw-r--r-- | lib/isc/x86_64/include/isc/atomic.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/lib/isc/x86_64/include/isc/atomic.h b/lib/isc/x86_64/include/isc/atomic.h new file mode 100644 index 0000000000000..0752d8f9a0d9a --- /dev/null +++ b/lib/isc/x86_64/include/isc/atomic.h @@ -0,0 +1,103 @@ +/* + * Copyright (C) 2005 Internet Systems Consortium, Inc. ("ISC") + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: atomic.h,v 1.2.20.1 2005/09/02 13:27:12 marka Exp $ */ + +#ifndef ISC_ATOMIC_H +#define ISC_ATOMIC_H 1 + +#include <isc/platform.h> +#include <isc/types.h> + +#ifdef ISC_PLATFORM_USEGCCASM + +/* We share the gcc-version with x86_32 */ +#error "impossible case. check build configuration" + +#elif defined(ISC_PLATFORM_USESTDASM) +/* + * The followings are "generic" assembly code which implements the same + * functionality in case the gcc extension cannot be used. It should be + * better to avoid inlining below, since we directly refer to specific + * registers for arguments, which would not actually correspond to the + * intended address or value in the embedded mnemonic. + */ +#include <isc/util.h> /* for 'UNUSED' macro */ + +static isc_int32_t +isc_atomic_xadd(isc_int32_t *p, isc_int32_t val) { + UNUSED(p); + UNUSED(val); + + __asm ( + "movq %rdi, %rdx\n" + "movl %esi, %eax\n" +#ifdef ISC_PLATFORM_USETHREADS + "lock;" +#endif + "xadd %eax, (%rdx)\n" + + /* + * set the return value directly in the register so that we + * can avoid guessing the correct position in the stack for a + * local variable. + */ + ); +} + +static void +isc_atomic_store(isc_int32_t *p, isc_int32_t val) { + UNUSED(p); + UNUSED(val); + + __asm ( + "movq %rdi, %rax\n" + "movl %esi, %edx\n" +#ifdef ISC_PLATFORM_USETHREADS + "lock;" +#endif + "xchgl (%rax), %edx\n" + ); +} + +static isc_int32_t +isc_atomic_cmpxchg(isc_int32_t *p, isc_int32_t cmpval, isc_int32_t val) { + UNUSED(p); + UNUSED(cmpval); + UNUSED(val); + + __asm ( + "movl %edx, %ecx\n" + "movl %esi, %eax\n" + "movq %rdi, %rdx\n" + +#ifdef ISC_PLATFORM_USETHREADS + "lock;" +#endif + /* + * If (%rdi) == %eax then (%rdi) := %edx. + % %eax is set to old (%ecx), which will be the return value. + */ + "cmpxchgl %ecx, (%rdx)" + ); +} + +#else /* !ISC_PLATFORM_USEGCCASM && !ISC_PLATFORM_USESTDASM */ + +#error "unsupported compiler. disable atomic ops by --disable-atomic" + +#endif +#endif /* ISC_ATOMIC_H */ |