Thomas Gleixner | b886d83c | 2019-06-01 10:08:55 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 2 | |
| 3 | #include <linux/linkage.h> |
Al Viro | 784d569 | 2016-01-11 11:04:34 -0500 | [diff] [blame] | 4 | #include <asm/export.h> |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 5 | |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 6 | .text |
| 7 | |
| 8 | /* |
| 9 | * Inputs: |
| 10 | * %esi : memory location to compare |
| 11 | * %eax : low 32 bits of old value |
| 12 | * %edx : high 32 bits of old value |
| 13 | * %ebx : low 32 bits of new value |
| 14 | * %ecx : high 32 bits of new value |
| 15 | */ |
Jiri Slaby | 6dcc562 | 2019-10-11 13:51:04 +0200 | [diff] [blame] | 16 | SYM_FUNC_START(cmpxchg8b_emu) |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 17 | |
| 18 | # |
| 19 | # Emulate 'cmpxchg8b (%esi)' on UP except we don't |
| 20 | # set the whole ZF thing (caller will just compare |
| 21 | # eax:edx with the expected value) |
| 22 | # |
Ingo Molnar | 131484c | 2015-05-28 12:21:47 +0200 | [diff] [blame] | 23 | pushfl |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 24 | cli |
| 25 | |
| 26 | cmpl (%esi), %eax |
Jan Beulich | 5f1d919 | 2014-09-24 08:40:14 +0100 | [diff] [blame] | 27 | jne .Lnot_same |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 28 | cmpl 4(%esi), %edx |
Jan Beulich | 5f1d919 | 2014-09-24 08:40:14 +0100 | [diff] [blame] | 29 | jne .Lhalf_same |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 30 | |
| 31 | movl %ebx, (%esi) |
| 32 | movl %ecx, 4(%esi) |
| 33 | |
Ingo Molnar | 131484c | 2015-05-28 12:21:47 +0200 | [diff] [blame] | 34 | popfl |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 35 | ret |
| 36 | |
Jan Beulich | 5f1d919 | 2014-09-24 08:40:14 +0100 | [diff] [blame] | 37 | .Lnot_same: |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 38 | movl (%esi), %eax |
Jan Beulich | 5f1d919 | 2014-09-24 08:40:14 +0100 | [diff] [blame] | 39 | .Lhalf_same: |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 40 | movl 4(%esi), %edx |
| 41 | |
Ingo Molnar | 131484c | 2015-05-28 12:21:47 +0200 | [diff] [blame] | 42 | popfl |
Arjan van de Ven | 79e1dd0 | 2009-09-30 17:07:54 +0200 | [diff] [blame] | 43 | ret |
| 44 | |
Jiri Slaby | 6dcc562 | 2019-10-11 13:51:04 +0200 | [diff] [blame] | 45 | SYM_FUNC_END(cmpxchg8b_emu) |
Al Viro | 784d569 | 2016-01-11 11:04:34 -0500 | [diff] [blame] | 46 | EXPORT_SYMBOL(cmpxchg8b_emu) |