projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 55e303ae A |
1 | /* |
| 2 | * Copyright (c) 2003 Apple Computer, Inc. All rights reserved. | |
| 3 | * | |
| 8f6c56a5 | 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
| 55e303ae | 5 | * |
| 8f6c56a5 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 | |
| 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 | |
| 8ad349bb | 24 | * limitations under the License. |
| 8f6c56a5 A |
25 | * |
| 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ | |
| 55e303ae A |
27 | */ |
| 28 | ||
| 29 | #define __NO_UNDERSCORES__ | |
| 30 | #include <i386/asm.h> | |
| 31 | #include <assym.s> | |
| 32 | ||
| 33 | Entry(mcount) | |
| 34 | pushl %ebp // setup mcount's frame | |
| 35 | movl %esp,%ebp | |
| 91447636 | 36 | pushl %eax // save %eax |
| 55e303ae A |
37 | pushf // save interrupt state |
| 38 | cli // disable interrupts | |
| 39 | ||
| 55e303ae A |
40 | // |
| 41 | // Check that this cpu is ready. | |
| 42 | // This delays the start of mcounting until a cpu is really prepared. | |
| 43 | // | |
| 91447636 | 44 | movl %gs:CPU_RUNNING,%eax |
| 55e303ae A |
45 | testl %eax,%eax |
| 46 | jz 1f | |
| 47 | ||
| 48 | // | |
| 49 | // Test for recursion as indicated by a per-cpu flag. | |
| 50 | // Skip if nested, otherwise set the flag and call the C mount(). | |
| 51 | // | |
| 91447636 | 52 | movl %gs:CPU_MCOUNT_OFF,%eax |
| 55e303ae A |
53 | testl %eax,%eax // test for recursion |
| 54 | jnz 1f | |
| 91447636 A |
55 | |
| 56 | incl %gs:CPU_MCOUNT_OFF // set recursion flag | |
| 55e303ae A |
57 | |
| 58 | movl (%ebp),%eax // frame pointer of mcount's caller | |
| 59 | movl 4(%eax),%eax // mcount's caller's return address | |
| 60 | pushl 4(%ebp) // push selfpc parameter for mcount() | |
| 61 | pushl %eax // push frompc parameter for mcount() | |
| 62 | call _mcount // call the C mcount | |
| 63 | addl $8,%esp // pop args | |
| 64 | ||
| 91447636 | 65 | decl %gs:CPU_MCOUNT_OFF // turn off recursion flag |
| 55e303ae A |
66 | 1: |
| 67 | popf // restore interrupt state | |
| 91447636 | 68 | popl %eax |
| 55e303ae A |
69 | movl %ebp,%esp // tear down mcount's frame |
| 70 | popl %ebp | |
| 71 | ret |