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Commit 8c7e58e6 authored by Brian Gerst's avatar Brian Gerst Committed by Tejun Heo
Browse files

x86: rework __per_cpu_load adjustments 



Impact: cleanup

Use cpu_number to determine if the adjustment is necessary.

Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 0bd74fa8

arch/x86/kernel/head_64.S

+8 −16
Original line number Diff line number Diff line
@@ -207,19 +207,15 @@ ENTRY(secondary_startup_64) 


#ifdef CONFIG_SMP

	/*

	 * early_gdt_base should point to the gdt_page in static percpu init

	 * data area.  Computing this requires two symbols - __per_cpu_load

	 * and per_cpu__gdt_page.  As linker can't do no such relocation, do

	 * it by hand.  As early_gdt_descr is manipulated by C code for

	 * secondary CPUs, this should be done only once for the boot CPU

	 * when early_gdt_descr_base contains zero.

	 * Fix up static pointers that need __per_cpu_load added.  The assembler

	 * is unable to do this directly.  This is only needed for the boot cpu.

	 * These values are set up with the correct base addresses by C code for

	 * secondary cpus.

	 */

	movq	early_gdt_descr_base(%rip), %rax

	testq	%rax, %rax

	jnz	1f

	movq	$__per_cpu_load, %rax

	addq	$per_cpu__gdt_page, %rax

	movq	%rax, early_gdt_descr_base(%rip)

	movq	initial_gs(%rip), %rax

	cmpl	$0, per_cpu__cpu_number(%rax)

	jne	1f

	addq	%rax, early_gdt_descr_base(%rip)

1:

#endif

	/*
@@ -431,12 +427,8 @@ NEXT_PAGE(level2_spare_pgt) 
	.globl early_gdt_descr

early_gdt_descr:

	.word	GDT_ENTRIES*8-1

#ifdef CONFIG_SMP

early_gdt_descr_base:

	.quad   0x0000000000000000

#else

	.quad	per_cpu__gdt_page

#endif



ENTRY(phys_base)

	/* This must match the first entry in level2_kernel_pgt */