+++ /dev/null
-/*
- * Copyright (c) 2004-2010 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.h
- * Purpose: Routines for handling the machine dependent
- * real-time clock.
- */
-
-#ifndef _I386_RTCLOCK_H_
-#define _I386_RTCLOCK_H_
-
-#ifndef ASSEMBLER
-typedef struct rtc_nanotime {
- volatile uint64_t tsc_base; /* timestamp */
- volatile uint64_t ns_base; /* nanoseconds */
- uint32_t scale; /* tsc -> nanosec multiplier */
- uint32_t shift; /* tsc -> nanosec shift/div */
- /* shift is overloaded with
- * lower 32bits of tsc_freq
- * on slower machines (SLOW_TSC_THRESHOLD) */
- volatile uint32_t generation; /* 0 == being updated */
- uint32_t spare1;
-} rtc_nanotime_t;
-
-#if 0
-#include <kern/etimer.h>
-#endif
-
-struct cpu_data;
-
-extern uint64_t tsc_rebase_abs_time;
-
-extern void _rtc_nanotime_store(
- uint64_t tsc,
- uint64_t nsec,
- uint32_t scale,
- uint32_t shift,
- rtc_nanotime_t *dst);
-
-extern void _rtc_nanotime_adjust(
- uint64_t tsc_base_delta,
- rtc_nanotime_t *dst);
-
-extern uint64_t _rtc_nanotime_read(
- rtc_nanotime_t *rntp,
- int slow);
-
-extern rtc_nanotime_t rtc_nanotime_info;
-#endif
-
-#define SLOW_TSC_THRESHOLD 1000067800 /* TSC is too slow for regular nanotime() algorithm */
-
-#if defined(__i386__)
-/*
- * Assembly snippet included in exception handlers and rtc_nanotime_read()
- * %edi points to nanotime info struct
- * %edx:%eax returns nanotime
- */
-#define 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 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
-
-#endif /* _I386_RTCLOCK_H_ */
projects / apple / xnu.git / blobdiff