| /* |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; version 2 |
| * of the License. |
| * |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/alternative-asm.h> |
| #include <asm/frame.h> |
| #include <asm/dwarf2.h> |
| |
| |
| .text |
| |
| /* |
| * Inputs: |
| * %esi : memory location to compare |
| * %eax : low 32 bits of old value |
| * %edx : high 32 bits of old value |
| * %ebx : low 32 bits of new value |
| * %ecx : high 32 bits of new value |
| */ |
| ENTRY(cmpxchg8b_emu) |
| CFI_STARTPROC |
| |
| # |
| # Emulate 'cmpxchg8b (%esi)' on UP except we don't |
| # set the whole ZF thing (caller will just compare |
| # eax:edx with the expected value) |
| # |
| cmpxchg8b_emu: |
| pushfl |
| cli |
| |
| cmpl (%esi), %eax |
| jne not_same |
| cmpl 4(%esi), %edx |
| jne half_same |
| |
| movl %ebx, (%esi) |
| movl %ecx, 4(%esi) |
| |
| popfl |
| ret |
| |
| not_same: |
| movl (%esi), %eax |
| half_same: |
| movl 4(%esi), %edx |
| |
| popfl |
| ret |
| |
| CFI_ENDPROC |
| ENDPROC(cmpxchg8b_emu) |