projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 1c79356b | 1 | /* |
| 39236c6e | 2 | * Copyright (c) 2008 Apple Inc. All rights reserved. |
| 1c79356b | 3 | * |
| 6d2010ae | 4 | * @APPLE_LICENSE_HEADER_START@ |
| 1c79356b | 5 | * |
| 2d21ac55 A |
6 | * This file contains Original Code and/or Modifications of Original Code |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 6d2010ae A |
9 | * compliance with the License. Please obtain a copy of the License at |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 2d21ac55 A |
12 | * |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 8f6c56a5 A |
15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 2d21ac55 A |
17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| 8f6c56a5 | 20 | * |
| 6d2010ae A |
21 | * @APPLE_LICENSE_HEADER_END@ |
| 22 | */ | |
| 23 | ||
| 39037602 A |
24 | #include <sys/time.h> |
| 25 | #include <mach/mach_time.h> | |
| 26 | #include <machine/cpu_capabilities.h> | |
| 27 | ||
| 28 | int __commpage_gettimeofday(struct timeval *); | |
| 29 | ||
| 30 | __attribute__((visibility("hidden"))) | |
| 31 | int __commpage_gettimeofday_internal(struct timeval *tp, uint64_t *tbr_out); | |
| 32 | ||
| 33 | #if defined(__x86_64__) || defined(__i386__) | |
| 34 | ||
| 35 | // XXX: must be kept in sync with __commpage_gettimeofday.s | |
| 36 | int | |
| 37 | __commpage_gettimeofday_internal(struct timeval *tp, uint64_t *tbr_out) | |
| 38 | { | |
| 39 | volatile uint32_t *gtod_generation_p = _COMM_PAGE_GTOD_GENERATION; | |
| 40 | volatile uint64_t *gtod_sec_base_p = _COMM_PAGE_GTOD_SEC_BASE; | |
| 41 | volatile uint64_t *gtod_ns_base_p = _COMM_PAGE_GTOD_NS_BASE; | |
| 42 | ||
| 43 | uint64_t tbr, gen, tod_secs, tod_nsecs, elapsed; | |
| 44 | while(1) { | |
| 45 | gen = *gtod_generation_p; | |
| 46 | tbr = mach_absolute_time(); | |
| 47 | tod_secs = *gtod_sec_base_p; | |
| 48 | tod_nsecs = *gtod_ns_base_p; | |
| 49 | uint64_t gen2 = *gtod_generation_p; | |
| 50 | if(__builtin_expect(gen, gen2) == gen2) | |
| 51 | break; | |
| 52 | } | |
| 53 | if (gen == 0) return KERN_FAILURE; | |
| 54 | elapsed = tbr - tod_nsecs; | |
| 55 | ||
| 56 | unsigned long secs; | |
| 57 | uint32_t nsec; | |
| 58 | #if defined(__x86_64__) | |
| 59 | secs = elapsed/NSEC_PER_SEC; | |
| 60 | nsec = elapsed % NSEC_PER_SEC; | |
| 61 | #elif defined(__i386__) | |
| 62 | uint32_t secs1, secs2; | |
| 63 | secs1 = elapsed >> 32; | |
| 64 | secs2 = elapsed; | |
| 65 | __asm__ ( | |
| 66 | "divl %4" | |
| 67 | : "=a" (secs), "=d" (nsec) | |
| 68 | : "0" (secs2), "1" (secs1), "rm" (NSEC_PER_SEC) | |
| 69 | ); | |
| 70 | #endif /* __i386 or __x86_64__ */ | |
| 71 | tp->tv_sec = tod_secs + secs; | |
| 72 | tp->tv_usec = nsec / NSEC_PER_USEC; | |
| 73 | ||
| 74 | if (tbr_out) *tbr_out = tbr; | |
| 75 | ||
| 76 | return KERN_SUCCESS; | |
| 77 | } | |
| 78 | ||
| 79 | #endif |