X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/e5568f75972dfc723778653c11cb6b4dc825716a..c910b4d9d2451126ae3917b931cd4390c11e1d52:/osfmk/i386/commpage/commpage_mach_absolute_time.s diff --git a/osfmk/i386/commpage/commpage_mach_absolute_time.s b/osfmk/i386/commpage/commpage_mach_absolute_time.s index 20e65ce00..f10baef8b 100644 --- a/osfmk/i386/commpage/commpage_mach_absolute_time.s +++ b/osfmk/i386/commpage/commpage_mach_absolute_time.s @@ -1,28 +1,37 @@ /* - * Copyright (c) 2003 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2003-2007 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * 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. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * 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 OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * 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_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include #include #include +#include + +#include .text .align 2, 0x90 @@ -32,3 +41,143 @@ Lmach_absolute_time: ret COMMPAGE_DESCRIPTOR(mach_absolute_time,_COMM_PAGE_ABSOLUTE_TIME,0,0) + + +/* return nanotime in %edx:%eax */ + +Lnanotime: + pushl %ebp + movl %esp,%ebp + pushl %esi + pushl %ebx + +0: + movl _COMM_PAGE_NT_GENERATION,%esi /* get generation (0 if being changed) */ + testl %esi,%esi /* if being updated, loop until stable */ + jz 0b + + lfence + rdtsc /* get TSC in %edx:%eax */ + lfence + + subl _COMM_PAGE_NT_TSC_BASE,%eax + sbbl _COMM_PAGE_NT_TSC_BASE+4,%edx + + movl _COMM_PAGE_NT_SCALE,%ecx + + movl %edx,%ebx + mull %ecx + movl %ebx,%eax + movl %edx,%ebx + mull %ecx + addl %ebx,%eax + adcl $0,%edx + + addl _COMM_PAGE_NT_NS_BASE,%eax + adcl _COMM_PAGE_NT_NS_BASE+4,%edx + + cmpl _COMM_PAGE_NT_GENERATION,%esi /* have the parameters changed? */ + jne 0b /* yes, loop until stable */ + + popl %ebx + popl %esi + popl %ebp + ret + + COMMPAGE_DESCRIPTOR(nanotime,_COMM_PAGE_NANOTIME,0,kSlow) + + +/* nanotime routine for machines slower than ~1Gz (SLOW_TSC_THRESHOLD) */ +Lnanotime_slow: + push %ebp + mov %esp,%ebp + push %esi + push %edi + push %ebx + +0: + movl _COMM_PAGE_NT_GENERATION,%esi + testl %esi,%esi /* if generation is 0, data being changed */ + jz 0b /* so loop until stable */ + + lfence + rdtsc /* get TSC in %edx:%eax */ + lfence + subl _COMM_PAGE_NT_TSC_BASE,%eax + sbbl _COMM_PAGE_NT_TSC_BASE+4,%edx + + pushl %esi /* save generation */ + /* + * Do the math to convert tsc ticks to nanoseconds. We first + * do long multiply of 1 billion times the tsc. Then we do + * long division by the tsc frequency + */ + mov $1000000000, %ecx /* number of nanoseconds in a second */ + mov %edx, %ebx + mul %ecx + mov %edx, %edi + mov %eax, %esi + mov %ebx, %eax + mul %ecx + add %edi, %eax + adc $0, %edx /* result in edx:eax:esi */ + mov %eax, %edi + mov _COMM_PAGE_NT_SHIFT,%ecx /* overloaded as the low 32 tscFreq */ + xor %eax, %eax + xchg %edx, %eax + div %ecx + xor %eax, %eax + mov %edi, %eax + div %ecx + mov %eax, %ebx + mov %esi, %eax + div %ecx + mov %ebx, %edx /* result in edx:eax */ + popl %esi /* recover generation */ + + add _COMM_PAGE_NT_NS_BASE,%eax + adc _COMM_PAGE_NT_NS_BASE+4,%edx + + cmpl _COMM_PAGE_NT_GENERATION,%esi /* have the parameters changed? */ + jne 0b /* yes, loop until stable */ + + pop %ebx + pop %edi + pop %esi + pop %ebp + ret /* result in edx:eax */ + + COMMPAGE_DESCRIPTOR(nanotime_slow,_COMM_PAGE_NANOTIME,kSlow,0) + + +/* The 64-bit version. We return the 64-bit nanotime in %rax, + * and by convention we must preserve %r9, %r10, and %r11. + */ + .text + .align 2 + .code64 +Lnanotime_64: // NB: must preserve r9, r10, and r11 + pushq %rbp // set up a frame for backtraces + movq %rsp,%rbp + movq $_COMM_PAGE_32_TO_64(_COMM_PAGE_TIME_DATA_START),%rsi +1: + movl _NT_GENERATION(%rsi),%r8d // get generation + testl %r8d,%r8d // if 0, data is being changed... + jz 1b // ...so loop until stable + lfence + rdtsc // edx:eax := tsc + lfence + shlq $32,%rdx // rax := ((edx << 32) | eax), ie 64-bit tsc + orq %rdx,%rax + subq _NT_TSC_BASE(%rsi), %rax // rax := (tsc - base_tsc) + movl _NT_SCALE(%rsi),%ecx + mulq %rcx // rdx:rax := (tsc - base_tsc) * scale + shrdq $32,%rdx,%rax // _COMM_PAGE_NT_SHIFT is always 32 + addq _NT_NS_BASE(%rsi),%rax // (((tsc - base_tsc) * scale) >> 32) + ns_base + + cmpl _NT_GENERATION(%rsi),%r8d // did the data change during computation? + jne 1b + popq %rbp + ret + + COMMPAGE_DESCRIPTOR(nanotime_64,_COMM_PAGE_NANOTIME,0,kSlow)