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Commit 30246557 authored by Luca Barbieri's avatar Luca Barbieri Committed by H. Peter Anvin
Browse files

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: default avatarDieter Stussy <kd6lvw+software@kd6lvw.ampr.org>
Signed-off-by: default avatarLuca Barbieri <luca@luca-barbieri.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org> 2.6.35
LKML-Reference: <tip-*@git.kernel.org>
parent 8fd49936

arch/x86/lib/atomic64_386_32.S

+128 −108
Original line number Diff line number Diff line
@@ -25,150 +25,170 @@ 
	CFI_ADJUST_CFA_OFFSET -4

.endm



.macro BEGIN func reg

$v = \reg



ENTRY(atomic64_\func\()_386)

	CFI_STARTPROC

	LOCK $v



.macro RETURN

	UNLOCK $v

#define BEGIN(op) \

.macro END; \

	CFI_ENDPROC; \

ENDPROC(atomic64_##op##_386); \

.purgem END; \

.endm; \

ENTRY(atomic64_##op##_386); \

	CFI_STARTPROC; \

	LOCK v;



#define RET \

	UNLOCK v; \

	ret

.endm



.macro END_

	CFI_ENDPROC

ENDPROC(atomic64_\func\()_386)

.purgem RETURN

.purgem END_

.purgem END

.endm



.macro END

RETURN

END_

.endm

.endm



BEGIN read %ecx

	movl  ($v), %eax

	movl 4($v), %edx

END



BEGIN set %esi

	movl %ebx,  ($v)

	movl %ecx, 4($v)

END



BEGIN xchg %esi

	movl  ($v), %eax

	movl 4($v), %edx

	movl %ebx,  ($v)

	movl %ecx, 4($v)

END



BEGIN add %ecx

	addl %eax,  ($v)

	adcl %edx, 4($v)

END



BEGIN add_return %ecx

	addl  ($v), %eax

	adcl 4($v), %edx

	movl %eax,  ($v)

	movl %edx, 4($v)

END



BEGIN sub %ecx

	subl %eax,  ($v)

	sbbl %edx, 4($v)

#define RET_END \

	RET; \

	END



BEGIN sub_return %ecx

#define v %ecx

BEGIN(read)

	movl  (v), %eax

	movl 4(v), %edx

RET_END

#undef v



#define v %esi

BEGIN(set)

	movl %ebx,  (v)

	movl %ecx, 4(v)

RET_END

#undef v



#define v  %esi

BEGIN(xchg)

	movl  (v), %eax

	movl 4(v), %edx

	movl %ebx,  (v)

	movl %ecx, 4(v)

RET_END

#undef v



#define v %ecx

BEGIN(add)

	addl %eax,  (v)

	adcl %edx, 4(v)

RET_END

#undef v



#define v %ecx

BEGIN(add_return)

	addl  (v), %eax

	adcl 4(v), %edx

	movl %eax,  (v)

	movl %edx, 4(v)

RET_END

#undef v



#define v %ecx

BEGIN(sub)

	subl %eax,  (v)

	sbbl %edx, 4(v)

RET_END

#undef v



#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



BEGIN inc %esi

	addl $1,  ($v)

	adcl $0, 4($v)

END



BEGIN inc_return %esi

	movl  ($v), %eax

	movl 4($v), %edx

	addl  (v), %eax

	adcl 4(v), %edx

	movl %eax,  (v)

	movl %edx, 4(v)

RET_END

#undef v



#define v %esi

BEGIN(inc)

	addl $1,  (v)

	adcl $0, 4(v)

RET_END

#undef v



#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



BEGIN dec %esi

	subl $1,  ($v)

	sbbl $0, 4($v)

END



BEGIN dec_return %esi

	movl  ($v), %eax

	movl 4($v), %edx

	movl %eax,  (v)

	movl %edx, 4(v)

RET_END

#undef v



#define v %esi

BEGIN(dec)

	subl $1,  (v)

	sbbl $0, 4(v)

RET_END

#undef v



#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