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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/lib/cmpxchg8b_emu.S
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/x86/lib/cmpxchg8b_emu.S')
-rw-r--r--arch/x86/lib/cmpxchg8b_emu.S57
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/x86/lib/cmpxchg8b_emu.S b/arch/x86/lib/cmpxchg8b_emu.S
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+++ 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 <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)