linux-kernel - Re: [tip:x86/fpu] x86/fpu: Rename XSAVE macros

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Date:	Wed, 23 Sep 2015 12:49:01 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Dave Hansen <dave.hansen@...ux.intel.com>
Cc:	linux-tip-commits@...r.kernel.org, torvalds@...ux-foundation.org,
	hpa@...or.com, dave.hansen@...ux.intel.com,
	linux-kernel@...r.kernel.org, mingo@...nel.org,
	peterz@...radead.org, fenghua.yu@...el.com, brgerst@...il.com,
	dvlasenk@...hat.com, tglx@...utronix.de,
	tim.c.chen@...ux.intel.com, luto@...capital.net
Subject: Re: [tip:x86/fpu] x86/fpu: Rename XSAVE macros

On Mon, Sep 14, 2015 at 05:21:07AM -0700, tip-bot for Dave Hansen wrote:
> Commit-ID:  d91cab78133d33b1dfd3d3fa7167fcbf74fb5f99
> Gitweb:     http://git.kernel.org/tip/d91cab78133d33b1dfd3d3fa7167fcbf74fb5f99
> Author:     Dave Hansen <dave.hansen@...ux.intel.com>
> AuthorDate: Wed, 2 Sep 2015 16:31:26 -0700
> Committer:  Ingo Molnar <mingo@...nel.org>
> CommitDate: Mon, 14 Sep 2015 12:21:46 +0200
> 
> x86/fpu: Rename XSAVE macros
> 
> There are two concepts that have some confusing naming:
>  1. Extended State Component numbers (currently called
>     XFEATURE_BIT_*)
>  2. Extended State Component masks (currently called XSTATE_*)
> 
> The numbers are (currently) from 0-9.  State component 3 is the
> bounds registers for MPX, for instance.
> 
> But when we want to enable "state component 3", we go set a bit
> in XCR0.  The bit we set is 1<<3.  We can check to see if a
> state component feature is enabled by looking at its bit.
> 
> The current 'xfeature_bit's are at best xfeature bit _numbers_.
> Calling them bits is at best inconsistent with ending the enum
> list with 'XFEATURES_NR_MAX'.
> 
> This patch renames the enum to be 'xfeature'.  These also
> happen to be what the Intel documentation calls a "state
> component".
> 
> We also want to differentiate these from the "XSTATE_*" macros.
> The "XSTATE_*" macros are a mask, and we rename them to match.
> 
> These macros are reasonably widely used so this patch is a
> wee bit big, but this really is just a rename.
> 
> The only non-mechanical part of this is the
> 
> 	s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/
> 
> We need a better name for it, but that's another patch.
> 
> Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
> Cc: Andy Lutomirski <luto@...capital.net>
> Cc: Borislav Petkov <bp@...en8.de>
> Cc: Brian Gerst <brgerst@...il.com>
> Cc: Denys Vlasenko <dvlasenk@...hat.com>
> Cc: Fenghua Yu <fenghua.yu@...el.com>
> Cc: H. Peter Anvin <hpa@...or.com>
> Cc: Linus Torvalds <torvalds@...ux-foundation.org>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Tim Chen <tim.c.chen@...ux.intel.com>
> Cc: dave@...1.net
> Cc: linux-kernel@...r.kernel.org
> Link: http://lkml.kernel.org/r/20150902233126.38653250@viggo.jf.intel.com
> [ Ported to v4.3-rc1. ]
> Signed-off-by: Ingo Molnar <mingo@...nel.org>
> ---

...

> @@ -558,7 +558,7 @@ static int __init twofish_init(void)
>  {
>  	const char *feature_name;
>  
> -	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
> +	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
>  		pr_info("CPU feature '%s' is not supported.\n", feature_name);
>  		return -ENODEV;
>  	}

---
From: Borislav Petkov <bp@...e.de>
Date: Wed, 23 Sep 2015 12:44:59 +0200
Subject: [PATCH] x86/crypto: Fixup uninitialized feature_name warning

Hand in &feature_name to cpu_has_xfeatures() as it is supposed to. Fixes
an uninitialized warning.

Fixes: d91cab78133d ("x86/fpu: Rename XSAVE macros")
Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/crypto/twofish_avx_glue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/crypto/twofish_avx_glue.c b/arch/x86/crypto/twofish_avx_glue.c
index 6f3738ced95e..b7a3904b953c 100644
--- a/arch/x86/crypto/twofish_avx_glue.c
+++ b/arch/x86/crypto/twofish_avx_glue.c
@@ -558,7 +558,7 @@ static int __init twofish_init(void)
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, &feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
-- 
2.3.5

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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