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authorChris Metcalf <cmetcalf@tilera.com>2011-05-26 19:52:04 +0400
committerChris Metcalf <cmetcalf@tilera.com>2011-05-26 19:52:04 +0400
commit7a0287df3e83a0012dfc496d4a8af9c1c5b126ef (patch)
tree27cc2f768de7e9014ffa899117bf219d0f20fb5e /arch/um/sys-i386/atomic64_cx8_32.S
parent6738d3210aabe3016a1b03cd98a7fc479c229197 (diff)
parent61c4f2c81c61f73549928dfd9f3e8f26aa36a8cf (diff)
downloadlinux-7a0287df3e83a0012dfc496d4a8af9c1c5b126ef.tar.xz
Merge tag 'v2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus
Diffstat (limited to 'arch/um/sys-i386/atomic64_cx8_32.S')
-rw-r--r--arch/um/sys-i386/atomic64_cx8_32.S225
1 files changed, 225 insertions, 0 deletions
diff --git a/arch/um/sys-i386/atomic64_cx8_32.S b/arch/um/sys-i386/atomic64_cx8_32.S
new file mode 100644
index 000000000000..1e901d3d4a95
--- /dev/null
+++ b/arch/um/sys-i386/atomic64_cx8_32.S
@@ -0,0 +1,225 @@
+/*
+ * atomic64_t for 586+
+ *
+ * Copied from arch/x86/lib/atomic64_cx8_32.S
+ *
+ * Copyright © 2010 Luca Barbieri
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/alternative-asm.h>
+#include <asm/dwarf2.h>
+
+.macro SAVE reg
+ pushl_cfi %\reg
+ CFI_REL_OFFSET \reg, 0
+.endm
+
+.macro RESTORE reg
+ popl_cfi %\reg
+ CFI_RESTORE \reg
+.endm
+
+.macro read64 reg
+ movl %ebx, %eax
+ movl %ecx, %edx
+/* we need LOCK_PREFIX since otherwise cmpxchg8b always does the write */
+ LOCK_PREFIX
+ cmpxchg8b (\reg)
+.endm
+
+ENTRY(atomic64_read_cx8)
+ CFI_STARTPROC
+
+ read64 %ecx
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_read_cx8)
+
+ENTRY(atomic64_set_cx8)
+ CFI_STARTPROC
+
+1:
+/* we don't need LOCK_PREFIX since aligned 64-bit writes
+ * are atomic on 586 and newer */
+ cmpxchg8b (%esi)
+ jne 1b
+
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_set_cx8)
+
+ENTRY(atomic64_xchg_cx8)
+ CFI_STARTPROC
+
+ movl %ebx, %eax
+ movl %ecx, %edx
+1:
+ LOCK_PREFIX
+ cmpxchg8b (%esi)
+ jne 1b
+
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_xchg_cx8)
+
+.macro addsub_return func ins insc
+ENTRY(atomic64_\func\()_return_cx8)
+ CFI_STARTPROC
+ SAVE ebp
+ SAVE ebx
+ SAVE esi
+ SAVE edi
+
+ movl %eax, %esi
+ movl %edx, %edi
+ movl %ecx, %ebp
+
+ read64 %ebp
+1:
+ movl %eax, %ebx
+ movl %edx, %ecx
+ \ins\()l %esi, %ebx
+ \insc\()l %edi, %ecx
+ LOCK_PREFIX
+ cmpxchg8b (%ebp)
+ jne 1b
+
+10:
+ movl %ebx, %eax
+ movl %ecx, %edx
+ RESTORE edi
+ RESTORE esi
+ RESTORE ebx
+ RESTORE ebp
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_\func\()_return_cx8)
+.endm
+
+addsub_return add add adc
+addsub_return sub sub sbb
+
+.macro incdec_return func ins insc
+ENTRY(atomic64_\func\()_return_cx8)
+ CFI_STARTPROC
+ SAVE ebx
+
+ read64 %esi
+1:
+ movl %eax, %ebx
+ movl %edx, %ecx
+ \ins\()l $1, %ebx
+ \insc\()l $0, %ecx
+ LOCK_PREFIX
+ cmpxchg8b (%esi)
+ jne 1b
+
+10:
+ movl %ebx, %eax
+ movl %ecx, %edx
+ RESTORE ebx
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_\func\()_return_cx8)
+.endm
+
+incdec_return inc add adc
+incdec_return dec sub sbb
+
+ENTRY(atomic64_dec_if_positive_cx8)
+ CFI_STARTPROC
+ SAVE ebx
+
+ read64 %esi
+1:
+ movl %eax, %ebx
+ movl %edx, %ecx
+ subl $1, %ebx
+ sbb $0, %ecx
+ js 2f
+ LOCK_PREFIX
+ cmpxchg8b (%esi)
+ jne 1b
+
+2:
+ movl %ebx, %eax
+ movl %ecx, %edx
+ RESTORE ebx
+ ret
+ CFI_ENDPROC
+ENDPROC(atomic64_dec_if_positive_cx8)
+
+ENTRY(atomic64_add_unless_cx8)
+ CFI_STARTPROC
+ SAVE ebp
+ SAVE ebx
+/* these just push these two parameters on the stack */
+ SAVE edi
+ SAVE esi
+
+ movl %ecx, %ebp
+ movl %eax, %esi
+ movl %edx, %edi
+
+ read64 %ebp
+1:
+ cmpl %eax, 0(%esp)
+ je 4f
+2:
+ movl %eax, %ebx
+ movl %edx, %ecx
+ addl %esi, %ebx
+ adcl %edi, %ecx
+ LOCK_PREFIX
+ cmpxchg8b (%ebp)
+ jne 1b
+
+ movl $1, %eax
+3:
+ addl $8, %esp
+ CFI_ADJUST_CFA_OFFSET -8
+ RESTORE ebx
+ RESTORE ebp
+ ret
+4:
+ cmpl %edx, 4(%esp)
+ jne 2b
+ xorl %eax, %eax
+ jmp 3b
+ CFI_ENDPROC
+ENDPROC(atomic64_add_unless_cx8)
+
+ENTRY(atomic64_inc_not_zero_cx8)
+ CFI_STARTPROC
+ SAVE ebx
+
+ read64 %esi
+1:
+ testl %eax, %eax
+ je 4f
+2:
+ movl %eax, %ebx
+ movl %edx, %ecx
+ addl $1, %ebx
+ adcl $0, %ecx
+ LOCK_PREFIX
+ cmpxchg8b (%esi)
+ jne 1b
+
+ movl $1, %eax
+3:
+ RESTORE ebx
+ ret
+4:
+ testl %edx, %edx
+ jne 2b
+ jmp 3b
+ CFI_ENDPROC
+ENDPROC(atomic64_inc_not_zero_cx8)