/* * Copyright (c) 2010 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ /* * @APPLE_FREE_COPYRIGHT@ */ /* * File: rtclock_asm_native.h * Purpose: Native routines for reading nanotime */ #ifndef _PAL_RTCLOCK_ASM_NATIVE_H_ #define _PAL_RTCLOCK_ASM_NATIVE_H_ #if defined(__i386__) /* * Assembly snippet included in exception handlers and rtc_nanotime_read() * %edi points to nanotime info struct * %edx:%eax returns nanotime */ #define PAL_RTC_NANOTIME_READ_FAST() \ 0: movl RNT_GENERATION(%edi),%esi /* being updated? */ ; \ testl %esi,%esi ; \ jz 0b /* wait until done */ ; \ lfence ; \ rdtsc ; \ lfence ; \ subl RNT_TSC_BASE(%edi),%eax ; \ sbbl RNT_TSC_BASE+4(%edi),%edx /* tsc - tsc_base */ ; \ movl RNT_SCALE(%edi),%ecx /* * scale factor */ ; \ movl %edx,%ebx ; \ mull %ecx ; \ movl %ebx,%eax ; \ movl %edx,%ebx ; \ mull %ecx ; \ addl %ebx,%eax ; \ adcl $0,%edx ; \ addl RNT_NS_BASE(%edi),%eax /* + ns_base */ ; \ adcl RNT_NS_BASE+4(%edi),%edx ; \ cmpl RNT_GENERATION(%edi),%esi /* check for update */ ; \ jne 0b /* do it all again */ #elif defined(__x86_64__) /* * Assembly snippet included in exception handlers and rtc_nanotime_read() * %rdi points to nanotime info struct. * %rax returns nanotime */ #define PAL_RTC_NANOTIME_READ_FAST() \ 0: movl RNT_GENERATION(%rdi),%esi ; \ test %esi,%esi /* info updating? */ ; \ jz 0b /* - wait if so */ ; \ lfence ; \ rdtsc ; \ lfence ; \ shlq $32,%rdx ; \ orq %rdx,%rax /* %rax := tsc */ ; \ subq RNT_TSC_BASE(%rdi),%rax /* tsc - tsc_base */ ; \ xorq %rcx,%rcx ; \ movl RNT_SCALE(%rdi),%ecx ; \ mulq %rcx /* delta * scale */ ; \ shrdq $32,%rdx,%rax /* %rdx:%rax >>= 32 */ ; \ addq RNT_NS_BASE(%rdi),%rax /* add ns_base */ ; \ cmpl RNT_GENERATION(%rdi),%esi /* repeat if changed */ ; \ jne 0b #endif /* !defined(x86_64) */ #endif /* _PAL_RTCLOCK_ASM_NATIVE_H_ */