From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Borislav Petkov <bp@suse.de>
Subject: [PATCH 3/4] x86, head_32: Remove second CPUID detection from default_entry
Date: Mon, 11 Feb 2013 15:22:17 +0100 [thread overview]
Message-ID: <1360592538-10643-4-git-send-email-bp@alien8.de> (raw)
In-Reply-To: <1360592538-10643-1-git-send-email-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
We do that once earlier now and cache it into new_cpu_data.cpuid_level
so no need for the EFLAGS.ID toggling dance anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/head_32.S | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 73e084a6d2c5..e893ac09ca03 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -410,18 +410,7 @@ default_entry:
/*
* Check if it is 486
*/
- movl $-1,X86_CPUID # -1 for no CPUID initially
- movb $4,X86 # at least 486
- pushfl # push EFLAGS
- popl %eax # get EFLAGS
- movl %eax,%ecx # save original EFLAGS
- xorl $0x200000,%eax # flip ID bit in EFLAGS
- pushl %eax # copy to EFLAGS
- popfl # set EFLAGS
- pushfl # get new EFLAGS
- popl %eax # put it in eax
- xorl %ecx,%eax # change in flags
- testl $0x200000,%eax # check if ID bit changed
+ cmpl $-1,X86_CPUID
je is486
/* get vendor info */
@@ -447,7 +436,9 @@ default_entry:
movb %cl,X86_MASK
movl %edx,X86_CAPABILITY
-is486: movl $0x50022,%ecx # set AM, WP, NE and MP
+is486:
+ movb $4,X86
+ movl $0x50022,%ecx # set AM, WP, NE and MP
movl %cr0,%eax
andl $0x80000011,%eax # Save PG,PE,ET
orl %ecx,%eax
--
1.8.1.3.535.ga923c31
next prev parent reply other threads:[~2013-02-11 14:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-11 14:22 [PATCH 0/4 -v3] x86, head_32: Some cleanups Borislav Petkov
2013-02-11 14:22 ` [PATCH 1/4] x86, head_32: Remove i386 pieces Borislav Petkov
2013-02-13 0:07 ` [tip:x86/asm] " tip-bot for Borislav Petkov
2013-02-11 14:22 ` [PATCH 2/4] x86: Detect CPUID support early at boot Borislav Petkov
2013-02-13 0:09 ` [tip:x86/asm] " tip-bot for Borislav Petkov
2013-02-11 14:22 ` Borislav Petkov [this message]
2013-02-11 15:49 ` [PATCH 3/4] x86, head_32: Remove second CPUID detection from default_entry H. Peter Anvin
2013-02-11 17:15 ` Borislav Petkov
2013-02-11 17:21 ` H. Peter Anvin
2013-02-13 0:10 ` [tip:x86/asm] " tip-bot for Borislav Petkov
2013-02-11 14:22 ` [PATCH 4/4] x86, head_32: Give the 6 label a real name Borislav Petkov
2013-02-13 0:11 ` [tip:x86/asm] " tip-bot for Borislav Petkov
2013-02-11 16:56 ` [PATCH 0/4 -v3] x86, head_32: Some cleanups H. Peter Anvin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1360592538-10643-4-git-send-email-bp@alien8.de \
--to=bp@alien8.de \
--cc=bp@suse.de \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).