Commit a44ef517 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
Browse files

arm64: remove processor_id 



The global processor_id is assigned the MIDR_EL1 value of the boot
CPU in the early init code, but is never referenced afterwards.

As the relevance of the MIDR_EL1 value of the boot CPU is debatable
anyway, especially under big.LITTLE, let's remove it before anyone
starts using it.

Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent b784a5d9

arch/arm64/kernel/head.S

+1 −6
Original line number Diff line number Diff line
@@ -244,7 +244,6 @@ ENTRY(stext) 
	bl	el2_setup			// Drop to EL1, w20=cpu_boot_mode

	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET

	bl	set_cpu_boot_mode_flag

	mrs	x22, midr_el1			// x22=cpuid



	bl	__vet_fdt

	bl	__create_page_tables		// x25=TTBR0, x26=TTBR1
@@ -427,7 +426,6 @@ __switch_data: 
	.quad	__mmap_switched

	.quad	__bss_start			// x6

	.quad	__bss_stop			// x7

	.quad	processor_id			// x4

	.quad	__fdt_pointer			// x5

	.quad	memstart_addr			// x6

	.quad	init_thread_union + THREAD_START_SP // sp
@@ -445,11 +443,10 @@ __mmap_switched: 
	str	xzr, [x6], #8			// Clear BSS

	b	1b

2:

	ldp	x4, x5, [x3], #16

	ldr	x5, [x3], #8

	ldr	x6, [x3], #8

	ldr	x16, [x3]

	mov	sp, x16

	str	x22, [x4]			// Save processor ID

	str	x21, [x5]			// Save FDT pointer

	str	x24, [x6]			// Save PHYS_OFFSET

	mov	x29, #0
@@ -621,8 +618,6 @@ ENTRY(secondary_startup) 
	/*

	 * Common entry point for secondary CPUs.

	 */

	mrs	x22, midr_el1			// x22=cpuid



	pgtbl	x25, x26, x28			// x25=TTBR0, x26=TTBR1

	bl	__cpu_setup			// initialise processor

arch/arm64/kernel/setup.c

+0 −3
Original line number Diff line number Diff line
@@ -63,9 +63,6 @@ 
#include <asm/efi.h>

#include <asm/virt.h>



unsigned int processor_id;

EXPORT_SYMBOL(processor_id);



unsigned long elf_hwcap __read_mostly;

EXPORT_SYMBOL_GPL(elf_hwcap);

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