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: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index ebb9e63..88f14a7 100644 (file)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -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
 

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 3852405..1783b38 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -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);