[PATCH] arm64: Get rid of struct cpu_table
Mark Rutland
mark.rutland at arm.com
Tue Mar 17 09:14:04 PDT 2015
On Fri, Mar 13, 2015 at 12:02:13PM +0000, Marc Zyngier wrote:
> struct cpu_table is an artifact left from the (very) early days of
> the arm64 port, and its only real use is to allow the most beautiful
> "AArch64 Processor" string to be displayed at boot time.
>
> Really? Yes, really.
>
> Let's get rid of it. In order to avoid another BogoMips-gate, the
> aforementioned string is preserved.
Nice!
> Acked-by: Catalin Marinas <catalin.marinas at arm.com>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Acked-by: Mark Rutland <mark.rutland at arm.com>
> ---
> arch/arm64/include/asm/cputable.h | 30 -------------------
> arch/arm64/kernel/Makefile | 2 +-
> arch/arm64/kernel/asm-offsets.c | 4 ---
> arch/arm64/kernel/cputable.c | 33 ---------------------
> arch/arm64/kernel/head.S | 61 ++++-----------------------------------
> arch/arm64/kernel/setup.c | 16 ++--------
> 6 files changed, 9 insertions(+), 137 deletions(-)
> delete mode 100644 arch/arm64/include/asm/cputable.h
> delete mode 100644 arch/arm64/kernel/cputable.c
>
> diff --git a/arch/arm64/include/asm/cputable.h b/arch/arm64/include/asm/cputable.h
> deleted file mode 100644
> index e3bd983..0000000
> --- a/arch/arm64/include/asm/cputable.h
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -/*
> - * arch/arm64/include/asm/cputable.h
> - *
> - * Copyright (C) 2012 ARM Ltd.
> - *
> - * This program is free software: you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License version 2 as
> - * published by the Free Software Foundation.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> - * GNU General Public License for more details.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program. If not, see <http://www.gnu.org/licenses/>.
> - */
> -#ifndef __ASM_CPUTABLE_H
> -#define __ASM_CPUTABLE_H
> -
> -struct cpu_info {
> - unsigned int cpu_id_val;
> - unsigned int cpu_id_mask;
> - const char *cpu_name;
> - unsigned long (*cpu_setup)(void);
> -};
> -
> -extern struct cpu_info *lookup_processor_type(unsigned int);
> -
> -#endif
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 5ee07ee..d5e7074 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -12,7 +12,7 @@ CFLAGS_REMOVE_insn.o = -pg
> CFLAGS_REMOVE_return_address.o = -pg
>
> # Object file lists.
> -arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
> +arm64-obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
> entry-fpsimd.o process.o ptrace.o setup.o signal.o \
> sys.o stacktrace.o time.o traps.o io.o vdso.o \
> hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o \
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index f7fa65d..14dd3d1 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -24,7 +24,6 @@
> #include <linux/kvm_host.h>
> #include <asm/thread_info.h>
> #include <asm/memory.h>
> -#include <asm/cputable.h>
> #include <asm/smp_plat.h>
> #include <asm/suspend.h>
> #include <asm/vdso_datapage.h>
> @@ -71,9 +70,6 @@ int main(void)
> BLANK();
> DEFINE(PAGE_SZ, PAGE_SIZE);
> BLANK();
> - DEFINE(CPU_INFO_SZ, sizeof(struct cpu_info));
> - DEFINE(CPU_INFO_SETUP, offsetof(struct cpu_info, cpu_setup));
> - BLANK();
> DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL);
> DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE);
> DEFINE(DMA_FROM_DEVICE, DMA_FROM_DEVICE);
> diff --git a/arch/arm64/kernel/cputable.c b/arch/arm64/kernel/cputable.c
> deleted file mode 100644
> index fd3993c..0000000
> --- a/arch/arm64/kernel/cputable.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -/*
> - * arch/arm64/kernel/cputable.c
> - *
> - * Copyright (C) 2012 ARM Ltd.
> - *
> - * This program is free software: you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License version 2 as
> - * published by the Free Software Foundation.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> - * GNU General Public License for more details.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program. If not, see <http://www.gnu.org/licenses/>.
> - */
> -
> -#include <linux/init.h>
> -
> -#include <asm/cputable.h>
> -
> -extern unsigned long __cpu_setup(void);
> -
> -struct cpu_info cpu_table[] = {
> - {
> - .cpu_id_val = 0x000f0000,
> - .cpu_id_mask = 0x000f0000,
> - .cpu_name = "AArch64 Processor",
> - .cpu_setup = __cpu_setup,
> - },
> - { /* Empty */ },
> -};
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index 8ce88e0..3ef9cbc 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -245,22 +245,12 @@ ENTRY(stext)
> 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
> - bl lookup_processor_type
> - mov x23, x0 // x23=current cpu_table
> - /*
> - * __error_p may end up out of range for cbz if text areas are
> - * aligned up to section sizes.
> - */
> - cbnz x23, 1f // invalid processor (x23=0)?
> - b __error_p
> -1:
> +
> bl __vet_fdt
> bl __create_page_tables // x25=TTBR0, x26=TTBR1
> /*
> * The following calls CPU specific code in a position independent
> - * manner. See arch/arm64/mm/proc.S for details. x23 = base of
> - * cpu_info structure selected by lookup_processor_type above.
> + * manner. See arch/arm64/mm/proc.S for details.
> * On return, the CPU will be ready for the MMU to be turned on and
> * the TCR will have been set.
> */
> @@ -268,8 +258,8 @@ ENTRY(stext)
> // MMU has been enabled
> adrp lr, __enable_mmu // return (PIC) address
> add lr, lr, #:lo12:__enable_mmu
> - ldr x12, [x23, #CPU_INFO_SETUP]
> - add x12, x12, x28 // __virt_to_phys
> + adrp x12, __cpu_setup
> + add x12, x12, #:lo12:__cpu_setup
> br x12 // initialise processor
> ENDPROC(stext)
>
> @@ -634,14 +624,10 @@ ENTRY(secondary_startup)
> * Common entry point for secondary CPUs.
> */
> mrs x22, midr_el1 // x22=cpuid
> - mov x0, x22
> - bl lookup_processor_type
> - mov x23, x0 // x23=current cpu_table
> - cbz x23, __error_p // invalid processor (x23=0)?
>
> pgtbl x25, x26, x28 // x25=TTBR0, x26=TTBR1
> - ldr x12, [x23, #CPU_INFO_SETUP]
> - add x12, x12, x28 // __virt_to_phys
> + adrp x12, __cpu_setup
> + add x12, x12, #:lo12:__cpu_setup
> blr x12 // initialise processor
>
> ldr x21, =secondary_data
> @@ -721,38 +707,3 @@ __error:
> 1: nop
> b 1b
> ENDPROC(__error)
> -
> -/*
> - * This function gets the processor ID in w0 and searches the cpu_table[] for
> - * a match. It returns a pointer to the struct cpu_info it found. The
> - * cpu_table[] must end with an empty (all zeros) structure.
> - *
> - * This routine can be called via C code and it needs to work with the MMU
> - * both disabled and enabled (the offset is calculated automatically).
> - */
> -ENTRY(lookup_processor_type)
> - adr x1, __lookup_processor_type_data
> - ldp x2, x3, [x1]
> - sub x1, x1, x2 // get offset between VA and PA
> - add x3, x3, x1 // convert VA to PA
> -1:
> - ldp w5, w6, [x3] // load cpu_id_val and cpu_id_mask
> - cbz w5, 2f // end of list?
> - and w6, w6, w0
> - cmp w5, w6
> - b.eq 3f
> - add x3, x3, #CPU_INFO_SZ
> - b 1b
> -2:
> - mov x3, #0 // unknown processor
> -3:
> - mov x0, x3
> - ret
> -ENDPROC(lookup_processor_type)
> -
> - .align 3
> - .type __lookup_processor_type_data, %object
> -__lookup_processor_type_data:
> - .quad .
> - .quad cpu_table
> - .size __lookup_processor_type_data, . - __lookup_processor_type_data
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index e8420f6..a19eae2 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -50,7 +50,6 @@
> #include <asm/cpu.h>
> #include <asm/cputype.h>
> #include <asm/elf.h>
> -#include <asm/cputable.h>
> #include <asm/cpufeature.h>
> #include <asm/cpu_ops.h>
> #include <asm/sections.h>
> @@ -83,7 +82,6 @@ unsigned int compat_elf_hwcap2 __read_mostly;
>
> DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
>
> -static const char *cpu_name;
> phys_addr_t __fdt_pointer __initdata;
>
> /*
> @@ -209,22 +207,12 @@ static void __init smp_build_mpidr_hash(void)
>
> static void __init setup_processor(void)
> {
> - struct cpu_info *cpu_info;
> u64 features, block;
> u32 cwg;
> int cls;
>
> - cpu_info = lookup_processor_type(read_cpuid_id());
> - if (!cpu_info) {
> - printk("CPU configuration botched (ID %08x), unable to continue.\n",
> - read_cpuid_id());
> - while (1);
> - }
> -
> - cpu_name = cpu_info->cpu_name;
> -
> - printk("CPU: %s [%08x] revision %d\n",
> - cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
> + printk("CPU: AArch64 Processor [%08x] revision %d\n",
> + read_cpuid_id(), read_cpuid_id() & 15);
>
> sprintf(init_utsname()->machine, ELF_PLATFORM);
> elf_hwcap = 0;
> --
> 2.1.4
>
>
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