[v2,2/2] x86: paravirt: make native_save_fl extern inline
diff mbox

Message ID 0dd024cd-e05a-0d67-c1bf-1a532714bb1a@zytor.com
State New
Headers show

Commit Message

H. Peter Anvin June 5, 2018, 5:31 p.m. UTC
On 06/05/18 10:28, H. Peter Anvin wrote:
> On 06/05/18 10:05, Nick Desaulniers wrote:
>> +
>> +/*
>> + * void native_restore_fl(unsigned long flags)
>> + * %rdi: flags
>> + */
>> +ENTRY(native_restore_fl)
>> +	push %_ASM_DI
>> +	popf
>> +	ret
>> +ENDPROC(native_restore_fl)
>> +EXPORT_SYMBOL(native_restore_fl)
>>
> 
> To work on i386, this would have to be %_ASM_AX in that case.
> 
> Something like this added to <asm/asm.h> might be useful; then you can
> simply:
> 
> 	push %_ASM_ARG1
> 

Version with fixed typo...

	-hpa

Comments

Sedat Dilek June 5, 2018, 5:46 p.m. UTC | #1
On Tue, Jun 5, 2018 at 7:31 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 06/05/18 10:28, H. Peter Anvin wrote:
>> On 06/05/18 10:05, Nick Desaulniers wrote:
>>> +
>>> +/*
>>> + * void native_restore_fl(unsigned long flags)
>>> + * %rdi: flags
>>> + */
>>> +ENTRY(native_restore_fl)
>>> +    push %_ASM_DI
>>> +    popf
>>> +    ret
>>> +ENDPROC(native_restore_fl)
>>> +EXPORT_SYMBOL(native_restore_fl)
>>>
>>
>> To work on i386, this would have to be %_ASM_AX in that case.
>>
>> Something like this added to <asm/asm.h> might be useful; then you can
>> simply:
>>
>>       push %_ASM_ARG1
>>
>
> Version with fixed typo...

Small typo in the commit-subject... s/argument registes/argument registers

- sed@ -
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Nick Desaulniers June 5, 2018, 5:52 p.m. UTC | #2
On 06/05/18 10:28, H. Peter Anvin wrote:
> On 06/05/18 10:05, Nick Desaulniers wrote:
>> +
>> +/*
>> + * void native_restore_fl(unsigned long flags)
>> + * %rdi: flags
>> + */
>> +ENTRY(native_restore_fl)
>> +    push %_ASM_DI
>> +    popf
>> +    ret
>> +ENDPROC(native_restore_fl)
>> +EXPORT_SYMBOL(native_restore_fl)
>>
>
> To work on i386, this would have to be %_ASM_AX in that case.

?

Does the kernel have a different calling convention for 32b x86? How
does that work? regparm=3? Does that need to be added to the
declaration?

> Something like this added to <asm/asm.h> might be useful; then you can
> simply:
>
>       push %_ASM_ARG1
>
> Version with fixed typo...

Oh, nice, thanks! I'll pick this up and add it to my patch set for v3
(or did you want me to review/sign-off now?) I can pick up Sedat's
suggestion.
H. Peter Anvin June 5, 2018, 6:06 p.m. UTC | #3
On 06/05/18 10:52, Nick Desaulniers wrote:
> 
> Does the kernel have a different calling convention for 32b x86? How
> does that work? regparm=3? Does that need to be added to the
> declaration?
> 

Yes, -mregparm=3.  No, doesn't need to be added to the declaration.


>> Something like this added to <asm/asm.h> might be useful; then you can
>> simply:
>>
>>       push %_ASM_ARG1
>>
>> Version with fixed typo...
> 
> Oh, nice, thanks! I'll pick this up and add it to my patch set for v3
> (or did you want me to review/sign-off now?) I can pick up Sedat's
> suggestion.
> 

Add it to your patchset and add your own signoff underneath mine.

	-hpa

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Patch
diff mbox

From 9946c03bc6648ea65e6f8e2576c390dca9555288 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@linux.intel.com>
Date: Tue, 5 Jun 2018 10:21:35 -0700
Subject: [PATCH] x86/asm: add _ASM_ARG* constants for argument registes to
 <asm/asm.h>

i386 and x86-64 uses different registers for arguments; make them
available so we don't have to #ifdef in the actual code.

Native size and specified size (q, l, w, b) versions are provided.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/include/asm/asm.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 219faaec51df..990770f9e76b 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -46,6 +46,65 @@ 
 #define _ASM_SI		__ASM_REG(si)
 #define _ASM_DI		__ASM_REG(di)
 
+#ifndef __x86_64__
+/* 32 bit */
+
+#define _ASM_ARG1	_ASM_AX
+#define _ASM_ARG2	_ASM_DX
+#define _ASM_ARG3	_ASM_CX
+
+#define _ASM_ARG1L	eax
+#define _ASM_ARG2L	edx
+#define _ASM_ARG3L	ecx
+
+#define _ASM_ARG1W	ax
+#define _ASM_ARG2W	dx
+#define _ASM_ARG3W	cx
+
+#define _ASM_ARG1B	al
+#define _ASM_ARG2B	dl
+#define _ASM_ARG3B	cl
+
+#else
+/* 64 bit */
+
+#define _ASM_ARG1	_ASM_DI
+#define _ASM_ARG2	_ASM_SI
+#define _ASM_ARG3	_ASM_DX
+#define _ASM_ARG4	_ASM_CX
+#define _ASM_ARG5	r8
+#define _ASM_ARG6	r9
+
+#define _ASM_ARG1Q	rdi
+#define _ASM_ARG2Q	rsi
+#define _ASM_ARG3Q	rdx
+#define _ASM_ARG4Q	rcx
+#define _ASM_ARG5Q	r8
+#define _ASM_ARG6Q	r9
+
+#define _ASM_ARG1L	edi
+#define _ASM_ARG2L	esi
+#define _ASM_ARG3L	edx
+#define _ASM_ARG4L	ecx
+#define _ASM_ARG5L	r8d
+#define _ASM_ARG6L	r9d
+
+#define _ASM_ARG1W	di
+#define _ASM_ARG2W	si
+#define _ASM_ARG3W	dx
+#define _ASM_ARG4W	cx
+#define _ASM_ARG5W	r8w
+#define _ASM_ARG6W	r9w
+
+#define _ASM_ARG1B	dil
+#define _ASM_ARG2B	sil
+#define _ASM_ARG3B	dl
+#define _ASM_ARG4B	cl
+#define _ASM_ARG5B	r8b
+#define _ASM_ARG6B	r9b
+
+#endif
+
 /*
  * Macros to generate condition code outputs from inline assembly,
  * The output operand must be type "bool".
-- 
2.14.4