projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| b0d623f7 A |
1 | /* |
| 2 | * Copyright (c) 2003 Apple Computer, Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 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 | |
| 9 | * compliance with the License. The rights granted to you under the License | |
| 10 | * may not be used to create, or enable the creation or redistribution of, | |
| 11 | * unlawful or unlicensed copies of an Apple operating system, or to | |
| 12 | * circumvent, violate, or enable the circumvention or violation of, any | |
| 13 | * terms of an Apple operating system software license agreement. | |
| 14 | * | |
| 15 | * Please obtain a copy of the License at | |
| 16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. | |
| 17 | * | |
| 18 | * The Original Code and all software distributed under the License are | |
| 19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
| 21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
| 23 | * Please see the License for the specific language governing rights and | |
| 24 | * limitations under the License. | |
| 25 | * | |
| 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ | |
| 27 | */ | |
| 28 | ||
| 29 | #define __NO_UNDERSCORES__ | |
| 30 | #include <i386/asm.h> | |
| 31 | #include <assym.s> | |
| 32 | ||
| 33 | Entry(mcount) | |
| 34 | pushq %rbp // setup mcount's frame | |
| 35 | movq %rsp,%rbp | |
| 36 | pushq %rax // save %eax | |
| 37 | pushf // save interrupt state | |
| 38 | cli // disable interrupts | |
| 39 | ||
| 40 | // | |
| 41 | // Check that this cpu is ready. | |
| 42 | // This delays the start of mcounting until a cpu is really prepared. | |
| 43 | // | |
| 44 | mov %gs,%ax | |
| 45 | test %ax,%ax | |
| 46 | jz 1f | |
| 47 | ||
| 48 | movl %gs:CPU_RUNNING,%eax | |
| 49 | testl %eax,%eax | |
| 50 | jz 1f | |
| 51 | ||
| 52 | // | |
| 53 | // Test for recursion as indicated by a per-cpu flag. | |
| 54 | // Skip if nested, otherwise set the flag and call the C mount(). | |
| 55 | // | |
| 56 | movl %gs:CPU_MCOUNT_OFF,%eax | |
| 57 | testl %eax,%eax // test for recursion | |
| 58 | jnz 1f | |
| 59 | ||
| 60 | incl %gs:CPU_MCOUNT_OFF // set recursion flag | |
| 61 | ||
| 62 | movq (%rbp),%rax // frame pointer of mcount's caller | |
| 63 | pushq %rdi | |
| 64 | pushq %rsi | |
| 65 | pushq %rdx | |
| 66 | pushq %rcx | |
| 67 | pushq %r8 | |
| 68 | pushq %r9 | |
| 69 | movq 8(%rax),%rdi // mcount's caller's return address | |
| 70 | movq 8(%rbp),%rsi // push selfpc parameter for mcount() | |
| 71 | ||
| 72 | call _mcount // call the C mcount | |
| 73 | ||
| 74 | popq %r9 | |
| 75 | popq %r8 | |
| 76 | popq %rcx | |
| 77 | popq %rdx | |
| 78 | popq %rsi | |
| 79 | popq %rdi | |
| 80 | ||
| 81 | decl %gs:CPU_MCOUNT_OFF // turn off recursion flag | |
| 82 | 1: | |
| 83 | popf // restore interrupt state | |
| 84 | popq %rax | |
| 85 | movq %rbp,%rsp // tear down mcount's frame | |
| 86 | popq %rbp | |
| 87 | ret |