From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- arch/x86/lib/cmpxchg8b_emu.S | 57 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 arch/x86/lib/cmpxchg8b_emu.S (limited to 'arch/x86/lib/cmpxchg8b_emu.S') diff --git a/arch/x86/lib/cmpxchg8b_emu.S b/arch/x86/lib/cmpxchg8b_emu.S new file mode 100644 index 00000000..828cb710 --- /dev/null +++ b/arch/x86/lib/cmpxchg8b_emu.S @@ -0,0 +1,57 @@ +/* + * 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 +#include +#include +#include + + +.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) -- cgit