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From: ebiederm@xmission.com (Eric W. Biederman)
To: Andi Kleen <ak@suse.de>
Cc: virtualization <virtualization@lists.linux-foundation.org>,
	<linux-kernel@vger.kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
	Dave Jones <davej@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jeremy Fitzhardinge <jeremy@goop.org>
Subject: [PATCH 02/12] i386 head.S: Remove unnecessary use of %ebx as the boot cpu flag
Date: Mon, 30 Apr 2007 09:49:31 -0600	[thread overview]
Message-ID: <m14pmx6ewk.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <m18xc96eyq.fsf@ebiederm.dsl.xmission.com> (Eric W. Biederman's message of "Mon, 30 Apr 2007 09:48:13 -0600")


Currently in head.S there are two ways we test to see if we
are the boot cpu.  By looking at %ebx and by looking at the
static variable ready.  When changing things around I have
found that it gets tricky to preserve %ebx.  So this
patch just switches head.S over to the more reliable
test of always using ready.

Hopefully later we can kill these tests entirely.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/i386/kernel/head.S |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)

diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index 9b10af6..aa9e28e 100644
--- a/arch/i386/kernel/head.S
+++ b/arch/i386/kernel/head.S
@@ -157,7 +157,6 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
 	jb 10b
 	movl %edi,(init_pg_tables_end - __PAGE_OFFSET)
 
-	xorl %ebx,%ebx				/* This is the boot CPU (BSP) */
 	jmp 3f
 /*
  * Non-boot CPU entry point; entered from trampoline.S
@@ -228,10 +227,6 @@ ENTRY(startup_32_smp)
 	wrmsr
 
 6:
-	/* This is a secondary processor (AP) */
-	xorl %ebx,%ebx
-	incl %ebx
-
 #endif /* CONFIG_SMP */
 3:
 
@@ -257,7 +252,7 @@ ENTRY(startup_32_smp)
 	popfl
 
 #ifdef CONFIG_SMP
-	andl %ebx,%ebx
+	cmpb $0, ready
 	jz  1f				/* Initial CPU cleans BSS */
 	jmp checkCPUtype
 1:
-- 
1.5.1.1.181.g2de0


  reply	other threads:[~2007-04-30 15:51 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-30 15:46 [PATCH 0/12] Early USB debug port and i386 boot cleanups Eric W. Biederman
2007-04-30 15:48 ` [PATCH 01/12] x86_64: Allow fixmaps to be used with the initial page table Eric W. Biederman
2007-04-30 15:49   ` Eric W. Biederman [this message]
2007-04-30 15:51     ` [PATCH 03/12] i386 head.S: Always run the full set of paging state Eric W. Biederman
2007-04-30 15:57       ` [PATCH 04/12] i386 voyager: Use modern techniques to setup and teardown low identiy mappings Eric W. Biederman
2007-04-30 16:03         ` [PATCH 05/12] i386: During page table initialization always set the leaf page table entries Eric W. Biederman
2007-04-30 16:09           ` [PATCH 06/12] i386: Minimum cpu detection cleanups Eric W. Biederman
2007-04-30 16:10             ` [PATCH 07/12] i386: Add missing !X86_PAE dependincy to the 2G/2G split Eric W. Biederman
2007-04-30 16:15               ` [PATCH 08/12] i386: Convert the boot time page tables to the kernels native format Eric W. Biederman
2007-04-30 16:26                 ` Andi Kleen
2007-04-30 16:42                   ` Eric W. Biederman
2007-04-30 16:32                 ` [PATCH 09/12] i386/x86_64: EHCI usb debug port early printk support Eric W. Biederman
2007-04-30 16:32                   ` [PATCH 10/12] i386: Introduce head32.c Eric W. Biederman
2007-04-30 16:33                     ` [PATCH 11/12] i386: Move setup_idt from head.S to head32.c Eric W. Biederman
2007-04-30 16:35                       ` [PATCH 12/12] i386: remove cpuid checking in head.S Eric W. Biederman
2007-04-30 17:56                   ` [PATCH 09/12] i386/x86_64: EHCI usb debug port early printk support Andi Kleen
2007-04-30 20:54                     ` Eric W. Biederman
2007-04-30 16:16               ` [PATCH 07/12] i386: Add missing !X86_PAE dependincy to the 2G/2G split H. Peter Anvin
2007-04-30 16:39                 ` Eric W. Biederman
2007-04-30 16:13             ` [PATCH 06/12] i386: Minimum cpu detection cleanups H. Peter Anvin
2007-04-30 16:19             ` Andi Kleen
2007-04-30 16:21           ` [PATCH 05/12] i386: During page table initialization always set the leaf page table entries Andi Kleen
2007-04-30 16:34           ` Jeremy Fitzhardinge
2007-04-30 17:06         ` [PATCH 04/12] i386 voyager: Use modern techniques to setup and teardown low identiy mappings James Bottomley
2007-04-30 16:23   ` [PATCH 01/12] x86_64: Allow fixmaps to be used with the initial page table Andi Kleen

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