| Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This program is free software; you can redistribute it and/or |
| 3 | * modify it under the terms of the GNU General Public License |
| 4 | * as published by the Free Software Foundation; version 2 |
| 5 | * of the License. |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #include <linux/linkage.h> |
| 10 | #include <asm/alternative-asm.h> |
| 11 | #include <asm/frame.h> |
| 12 | #include <asm/dwarf2.h> |
| 13 | |
| 14 | |
| 15 | .text |
| 16 | |
| 17 | /* |
| 18 | * Inputs: |
| 19 | * %esi : memory location to compare |
| 20 | * %eax : low 32 bits of old value |
| 21 | * %edx : high 32 bits of old value |
| 22 | * %ebx : low 32 bits of new value |
| 23 | * %ecx : high 32 bits of new value |
| 24 | */ |
| 25 | ENTRY(cmpxchg8b_emu) |
| 26 | CFI_STARTPROC |
| 27 | |
| 28 | # |
| 29 | # Emulate 'cmpxchg8b (%esi)' on UP except we don't |
| 30 | # set the whole ZF thing (caller will just compare |
| 31 | # eax:edx with the expected value) |
| 32 | # |
| 33 | cmpxchg8b_emu: |
| 34 | pushfl |
| 35 | cli |
| 36 | |
| 37 | cmpl (%esi), %eax |
| 38 | jne not_same |
| 39 | cmpl 4(%esi), %edx |
| 40 | jne half_same |
| 41 | |
| 42 | movl %ebx, (%esi) |
| 43 | movl %ecx, 4(%esi) |
| 44 | |
| 45 | popfl |
| 46 | ret |
| 47 | |
| 48 | not_same: |
| 49 | movl (%esi), %eax |
| 50 | half_same: |
| 51 | movl 4(%esi), %edx |
| 52 | |
| 53 | popfl |
| 54 | ret |
| 55 | |
| 56 | CFI_ENDPROC |
| 57 | ENDPROC(cmpxchg8b_emu) |