/*
- * 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 <sys/appleapiopts.h>
#include <machine/cpu_capabilities.h>
#include <machine/commpage.h>
+#include <i386/asm.h>
+
+#include <assym.s>
.text
.align 2, 0x90
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)
projects / apple / xnu.git / blobdiff