/*
* Copyright (c) 2003 Apple Computer, 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@
*/
#define __NO_UNDERSCORES__
#include <i386/asm.h>
#include <assym.s>
Entry(mcount)
pushq %rbp // setup mcount's frame
movq %rsp,%rbp
pushq %rax // save %eax
pushf // save interrupt state
cli // disable interrupts
//
// Check that this cpu is ready.
// This delays the start of mcounting until a cpu is really prepared.
//
mov %gs,%ax
test %ax,%ax
jz 1f
movl %gs:CPU_RUNNING,%eax
testl %eax,%eax
jz 1f
//
// Test for recursion as indicated by a per-cpu flag.
// Skip if nested, otherwise set the flag and call the C mount().
//
movl %gs:CPU_MCOUNT_OFF,%eax
testl %eax,%eax // test for recursion
jnz 1f
incl %gs:CPU_MCOUNT_OFF // set recursion flag
movq (%rbp),%rax // frame pointer of mcount's caller
pushq %rdi
pushq %rsi
pushq %rdx
pushq %rcx
pushq %r8
pushq %r9
movq 8(%rax),%rdi // mcount's caller's return address
movq 8(%rbp),%rsi // push selfpc parameter for mcount()
call _mcount // call the C mcount
popq %r9
popq %r8
popq %rcx
popq %rdx
popq %rsi
popq %rdi
decl %gs:CPU_MCOUNT_OFF // turn off recursion flag
1:
popf // restore interrupt state
popq %rax
movq %rbp,%rsp // tear down mcount's frame
popq %rbp
ret