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arm64: Get rid of struct cpu_table

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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.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Marc Zyngier 2015-03-18 14:55:20 +00:00 committed by Will Deacon
parent 62aa9655b8
commit a591ede4cd
6 changed files with 8 additions and 153 deletions
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30
arch/arm64/include/asm/cputable.h
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@ -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

2
arch/arm64/kernel/Makefile
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@ -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 \

4
arch/arm64/kernel/asm-offsets.c
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@ -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);

33
arch/arm64/kernel/cputable.c
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@ -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 */ },
};

76
arch/arm64/kernel/head.S
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@ -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.
* The following calls CPU setup code, 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.
*/
@ -268,9 +258,7 @@ 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
br x12 // initialise processor
b __cpu_setup // initialise processor
ENDPROC(stext)
/*
@ -634,15 +622,9 @@ 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
blr x12 // initialise processor
bl __cpu_setup // initialise processor
ldr x21, =secondary_data
ldr x27, =__secondary_switched // address to jump to after enabling the MMU
@ -708,51 +690,3 @@ ENDPROC(__calc_phys_offset)
.align 3
1: .quad .
.quad PAGE_OFFSET
/*
* Exception handling. Something went wrong and we can't proceed. We ought to
* tell the user, but since we don't have any guarantee that we're even
* running on the right architecture, we do virtually nothing.
*/
__error_p:
ENDPROC(__error_p)
__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

16
arch/arm64/kernel/setup.c
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@ -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>
@ -84,7 +83,6 @@ unsigned int compat_elf_hwcap2 __read_mostly;
DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
static const char *cpu_name;
phys_addr_t __fdt_pointer __initdata;
/*
@ -234,22 +232,12 @@ void __init up_late_init(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;