Commit 69732102 authored by Pingfan Liu's avatar Pingfan Liu Committed by Thomas Gleixner
Browse files

x86/realmode: Remove trampoline_status 



There is no reader of trampoline_status, it's only written.

It turns out that after commit ce4b1b16 ("x86/smpboot: Initialize
secondary CPU only if master CPU will wait for it"), trampoline_status is
not needed any more.

Signed-off-by: default avatarPingfan Liu <kernelfans@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1563266424-3472-1-git-send-email-kernelfans@gmail.com
parent 5f9e832c

arch/x86/include/asm/realmode.h

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ struct real_mode_header { 
	u32	ro_end;

	/* SMP trampoline */

	u32	trampoline_start;

	u32	trampoline_status;

	u32	trampoline_header;

#ifdef CONFIG_X86_64

	u32	trampoline_pgd;

arch/x86/kernel/smpboot.c

+0 −5
Original line number Diff line number Diff line
@@ -1023,8 +1023,6 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) 
static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,

		       int *cpu0_nmi_registered)

{

	volatile u32 *trampoline_status =

		(volatile u32 *) __va(real_mode_header->trampoline_status);

	/* start_ip had better be page-aligned! */

	unsigned long start_ip = real_mode_header->trampoline_start;
@@ -1116,9 +1114,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, 
		}

	}



	/* mark "stuck" area as not stuck */

	*trampoline_status = 0;



	if (x86_platform.legacy.warm_reset) {

		/*

		 * Cleanup possible dangling ends...

arch/x86/realmode/rm/header.S

+0 −1
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ GLOBAL(real_mode_header) 
	.long	pa_ro_end

	/* SMP trampoline */

	.long	pa_trampoline_start

	.long	pa_trampoline_status

	.long	pa_trampoline_header

#ifdef CONFIG_X86_64

	.long	pa_trampoline_pgd;

arch/x86/realmode/rm/trampoline_32.S

+0 −3
Original line number Diff line number Diff line
@@ -41,9 +41,6 @@ ENTRY(trampoline_start) 


	movl	tr_start, %eax	# where we need to go



	movl	$0xA5A5A5A5, trampoline_status

				# write marker for master knows we're running



	/*

	 * GDT tables in non default location kernel can be beyond 16MB and

	 * lgdt will not be able to load the address as in real mode default

arch/x86/realmode/rm/trampoline_64.S

+0 −3
Original line number Diff line number Diff line
@@ -49,9 +49,6 @@ ENTRY(trampoline_start) 
	mov	%ax, %es

	mov	%ax, %ss



	movl	$0xA5A5A5A5, trampoline_status

	# write marker for master knows we're running



	# Setup stack

	movl	$rm_stack_end, %esp

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