x86, asm: Refactor atomic64_386_32.S to support old binutils and be cleaner

The old code didn't work on binutils 2.12 because setting a symbol to
a register apparently requires a fairly recent version.

This commit refactors the code to use the C preprocessor instead, and
in the process makes the whole code a bit easier to understand.

The object code produced is unchanged as expected.

This fixes kernel bugzilla 16506.

Reported-by: Dieter Stussy <kd6lvw+software@kd6lvw.ampr.org>
Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org> 2.6.35
LKML-Reference: <tip-*@git.kernel.org>
This commit is contained in:
Luca Barbieri 2010-08-06 04:04:38 +02:00 committed by H. Peter Anvin
parent 8fd49936a8
commit 30246557a0

View File

@ -25,150 +25,170 @@
CFI_ADJUST_CFA_OFFSET -4
.endm
.macro BEGIN func reg
$v = \reg
#define BEGIN(op) \
.macro END; \
CFI_ENDPROC; \
ENDPROC(atomic64_##op##_386); \
.purgem END; \
.endm; \
ENTRY(atomic64_##op##_386); \
CFI_STARTPROC; \
LOCK v;
ENTRY(atomic64_\func\()_386)
CFI_STARTPROC
LOCK $v
.macro RETURN
UNLOCK $v
#define RET \
UNLOCK v; \
ret
.endm
.macro END_
CFI_ENDPROC
ENDPROC(atomic64_\func\()_386)
.purgem RETURN
.purgem END_
.purgem END
.endm
#define RET_END \
RET; \
END
.macro END
RETURN
END_
.endm
.endm
#define v %ecx
BEGIN(read)
movl (v), %eax
movl 4(v), %edx
RET_END
#undef v
BEGIN read %ecx
movl ($v), %eax
movl 4($v), %edx
END
#define v %esi
BEGIN(set)
movl %ebx, (v)
movl %ecx, 4(v)
RET_END
#undef v
BEGIN set %esi
movl %ebx, ($v)
movl %ecx, 4($v)
END
#define v %esi
BEGIN(xchg)
movl (v), %eax
movl 4(v), %edx
movl %ebx, (v)
movl %ecx, 4(v)
RET_END
#undef v
BEGIN xchg %esi
movl ($v), %eax
movl 4($v), %edx
movl %ebx, ($v)
movl %ecx, 4($v)
END
#define v %ecx
BEGIN(add)
addl %eax, (v)
adcl %edx, 4(v)
RET_END
#undef v
BEGIN add %ecx
addl %eax, ($v)
adcl %edx, 4($v)
END
#define v %ecx
BEGIN(add_return)
addl (v), %eax
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
RET_END
#undef v
BEGIN add_return %ecx
addl ($v), %eax
adcl 4($v), %edx
movl %eax, ($v)
movl %edx, 4($v)
END
#define v %ecx
BEGIN(sub)
subl %eax, (v)
sbbl %edx, 4(v)
RET_END
#undef v
BEGIN sub %ecx
subl %eax, ($v)
sbbl %edx, 4($v)
END
BEGIN sub_return %ecx
#define v %ecx
BEGIN(sub_return)
negl %edx
negl %eax
sbbl $0, %edx
addl ($v), %eax
adcl 4($v), %edx
movl %eax, ($v)
movl %edx, 4($v)
END
addl (v), %eax
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
RET_END
#undef v
BEGIN inc %esi
addl $1, ($v)
adcl $0, 4($v)
END
#define v %esi
BEGIN(inc)
addl $1, (v)
adcl $0, 4(v)
RET_END
#undef v
BEGIN inc_return %esi
movl ($v), %eax
movl 4($v), %edx
#define v %esi
BEGIN(inc_return)
movl (v), %eax
movl 4(v), %edx
addl $1, %eax
adcl $0, %edx
movl %eax, ($v)
movl %edx, 4($v)
END
movl %eax, (v)
movl %edx, 4(v)
RET_END
#undef v
BEGIN dec %esi
subl $1, ($v)
sbbl $0, 4($v)
END
#define v %esi
BEGIN(dec)
subl $1, (v)
sbbl $0, 4(v)
RET_END
#undef v
BEGIN dec_return %esi
movl ($v), %eax
movl 4($v), %edx
#define v %esi
BEGIN(dec_return)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
sbbl $0, %edx
movl %eax, ($v)
movl %edx, 4($v)
END
movl %eax, (v)
movl %edx, 4(v)
RET_END
#undef v
BEGIN add_unless %ecx
#define v %ecx
BEGIN(add_unless)
addl %eax, %esi
adcl %edx, %edi
addl ($v), %eax
adcl 4($v), %edx
addl (v), %eax
adcl 4(v), %edx
cmpl %eax, %esi
je 3f
1:
movl %eax, ($v)
movl %edx, 4($v)
movl %eax, (v)
movl %edx, 4(v)
movl $1, %eax
2:
RETURN
RET
3:
cmpl %edx, %edi
jne 1b
xorl %eax, %eax
jmp 2b
END_
END
#undef v
BEGIN inc_not_zero %esi
movl ($v), %eax
movl 4($v), %edx
#define v %esi
BEGIN(inc_not_zero)
movl (v), %eax
movl 4(v), %edx
testl %eax, %eax
je 3f
1:
addl $1, %eax
adcl $0, %edx
movl %eax, ($v)
movl %edx, 4($v)
movl %eax, (v)
movl %edx, 4(v)
movl $1, %eax
2:
RETURN
RET
3:
testl %edx, %edx
jne 1b
jmp 2b
END_
END
#undef v
BEGIN dec_if_positive %esi
movl ($v), %eax
movl 4($v), %edx
#define v %esi
BEGIN(dec_if_positive)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
sbbl $0, %edx
js 1f
movl %eax, ($v)
movl %edx, 4($v)
movl %eax, (v)
movl %edx, 4(v)
1:
END
RET_END
#undef v