diff options
| author |   Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
|---|---|---|
| committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
| commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
| tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/lib/cmpxchg16b_emu.S | |
| parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) | |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/lib/cmpxchg16b_emu.S')
| -rw-r--r-- | kernel/arch/x86/lib/cmpxchg16b_emu.S | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/kernel/arch/x86/lib/cmpxchg16b_emu.S b/kernel/arch/x86/lib/cmpxchg16b_emu.S new file mode 100644 index 000000000..40a172541 --- /dev/null +++ b/kernel/arch/x86/lib/cmpxchg16b_emu.S @@ -0,0 +1,59 @@ +/* + * 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/dwarf2.h> +#include <asm/percpu.h> + +.text + +/* + * Inputs: + * %rsi : memory location to compare + * %rax : low 64 bits of old value + * %rdx : high 64 bits of old value + * %rbx : low 64 bits of new value + * %rcx : high 64 bits of new value + * %al : Operation successful + */ +ENTRY(this_cpu_cmpxchg16b_emu) +CFI_STARTPROC + +# +# Emulate 'cmpxchg16b %gs:(%rsi)' except we return the result in %al not +# via the ZF. Caller will access %al to get result. +# +# Note that this is only useful for a cpuops operation. Meaning that we +# do *not* have a fully atomic operation but just an operation that is +# *atomic* on a single cpu (as provided by the this_cpu_xx class of +# macros). +# + pushfq_cfi + cli + + cmpq PER_CPU_VAR((%rsi)), %rax + jne .Lnot_same + cmpq PER_CPU_VAR(8(%rsi)), %rdx + jne .Lnot_same + + movq %rbx, PER_CPU_VAR((%rsi)) + movq %rcx, PER_CPU_VAR(8(%rsi)) + + CFI_REMEMBER_STATE + popfq_cfi + mov $1, %al + ret + + CFI_RESTORE_STATE +.Lnot_same: + popfq_cfi + xor %al,%al + ret + +CFI_ENDPROC + +ENDPROC(this_cpu_cmpxchg16b_emu) |