[PATCH v4 2/5] arm64: remove processor_id

[Ard Biesheuvel]

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.

Reviewed-by: Mark Rutland <mark.rutland at arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
---
 arch/arm64/kernel/head.S  | 10 +++-------
 arch/arm64/kernel/setup.c |  3 ---
 2 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 8ce88e08c030..003db2eadd7a 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -244,8 +244,7 @@ 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
-	mov	x0, x22
+	mrs	x0, midr_el1
 	bl	lookup_processor_type
 	mov	x23, x0				// x23=current cpu_table
 	/*
@@ -439,7 +438,6 @@ __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
@@ -457,11 +455,10 @@ __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
@@ -633,8 +630,7 @@ ENTRY(secondary_startup)
 	/*
 	 * Common entry point for secondary CPUs.
 	 */
-	mrs	x22, midr_el1			// x22=cpuid
-	mov	x0, x22
+	mrs	x0, midr_el1
 	bl	lookup_processor_type
 	mov	x23, x0				// x23=current cpu_table
 	cbz	x23, __error_p			// invalid processor (x23=0)?
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index e8420f635bd4..8b82ef19b81b 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -63,9 +63,6 @@
 #include <asm/psci.h>
 #include <asm/efi.h>
 
-unsigned int processor_id;
-EXPORT_SYMBOL(processor_id);
-
 unsigned long elf_hwcap __read_mostly;
 EXPORT_SYMBOL_GPL(elf_hwcap);
 
-- 
1.8.3.2