Commit 50359501 authored Jan 30, 2008 by Ian Campbell Committed by Ingo Molnar Jan 30, 2008

x86_32: remove unnecessary use of %ebx as the boot cpu flag



Currently in head_32.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>
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Mika Penttilä <mika.penttila@kolumbus.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 43238382

arch/x86/kernel/head_32.S

+1 −6

Original line number	Diff line number	Diff line
		@@ -199,7 +199,6 @@ default_entry:
		addl $0x67, %eax /* 0x67 == _PAGE_TABLE */
		movl %eax, 4092(%edx)

		xorl %ebx,%ebx /* This is the boot CPU (BSP) */
		jmp 3f
		/*
		* Non-boot CPU entry point; entered from trampoline.S
		@@ -268,10 +267,6 @@ ENTRY(startup_32_smp)
		wrmsr

		6:
		/* This is a secondary processor (AP) */
		xorl %ebx,%ebx
		incl %ebx

		#endif /* CONFIG_SMP */
		3:

		@@ -297,7 +292,7 @@ ENTRY(startup_32_smp)
		popfl

		#ifdef CONFIG_SMP
		andl %ebx,%ebx
		cmpb $0, ready
		jz 1f /* Initial CPU cleans BSS */
		jmp checkCPUtype
		1:

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