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arm64: cpuinfo: record cpu system register values

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Several kernel subsystems need to know details about CPU system register
values, sometimes for CPUs other than that they are executing on. Rather
than hard-coding system register accesses and cross-calls for these
cases, this patch adds logic to record various system register values at
boot-time. This may be used for feature reporting, firmware bug
detection, etc.

Separate hooks are added for the boot and hotplug paths to enable
one-time intialisation and cold/warm boot value mismatch detection in
later patches.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Rutland 2014-07-16 16:32:44 +01:00 committed by Catalin Marinas
parent 89c4a306e7
commit df857416a1
5 changed files with 144 additions and 4 deletions
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59
arch/arm64/include/asm/cpu.h Normal file
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@ -0,0 +1,59 @@
/*
* Copyright (C) 2014 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_CPU_H
#define __ASM_CPU_H
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/percpu.h>
/*
* Records attributes of an individual CPU.
*/
struct cpuinfo_arm64 {
struct cpu cpu;
u32 reg_ctr;
u32 reg_cntfrq;
u32 reg_dczid;
u32 reg_midr;
u64 reg_id_aa64isar0;
u64 reg_id_aa64isar1;
u64 reg_id_aa64mmfr0;
u64 reg_id_aa64mmfr1;
u64 reg_id_aa64pfr0;
u64 reg_id_aa64pfr1;
u32 reg_id_isar0;
u32 reg_id_isar1;
u32 reg_id_isar2;
u32 reg_id_isar3;
u32 reg_id_isar4;
u32 reg_id_isar5;
u32 reg_id_mmfr0;
u32 reg_id_mmfr1;
u32 reg_id_mmfr2;
u32 reg_id_mmfr3;
u32 reg_id_pfr0;
u32 reg_id_pfr1;
};
DECLARE_PER_CPU(struct cpuinfo_arm64, cpu_data);
void cpuinfo_store_cpu(void);
void __init cpuinfo_store_boot_cpu(void);
#endif /* __ASM_CPU_H */

3
arch/arm64/kernel/Makefile
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@ -15,7 +15,8 @@ CFLAGS_REMOVE_return_address.o = -pg
arm64-obj-y := cputable.o 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 cpu_ops.o insn.o return_address.o
hyp-stub.o psci.o cpu_ops.o insn.o return_address.o \
cpuinfo.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o

73
arch/arm64/kernel/cpuinfo.c Normal file
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@ -0,0 +1,73 @@
/*
* Record and handle CPU attributes.
*
* Copyright (C) 2014 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 <asm/arch_timer.h>
#include <asm/cachetype.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <linux/init.h>
#include <linux/smp.h>
/*
* In case the boot CPU is hotpluggable, we record its initial state and
* current state separately. Certain system registers may contain different
* values depending on configuration at or after reset.
*/
DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
static struct cpuinfo_arm64 boot_cpu_data;
static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
{
info->reg_cntfrq = arch_timer_get_cntfrq();
info->reg_ctr = read_cpuid_cachetype();
info->reg_dczid = read_cpuid(DCZID_EL0);
info->reg_midr = read_cpuid_id();
info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
}
void cpuinfo_store_cpu(void)
{
struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
__cpuinfo_store_cpu(info);
}
void __init cpuinfo_store_boot_cpu(void)
{
struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
__cpuinfo_store_cpu(info);
boot_cpu_data = *info;
}

7
arch/arm64/kernel/setup.c
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@ -45,6 +45,7 @@
#include <linux/efi.h>
#include <asm/fixmap.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/elf.h>
#include <asm/cputable.h>
@ -219,6 +220,8 @@ static void __init setup_processor(void)
sprintf(init_utsname()->machine, ELF_PLATFORM);
elf_hwcap = 0;
cpuinfo_store_boot_cpu();
/*
* Check for sane CTR_EL0.CWG value.
*/
@ -417,14 +420,12 @@ static int __init arm64_device_init(void)
}
arch_initcall_sync(arm64_device_init);
static DEFINE_PER_CPU(struct cpu, cpu_data);
static int __init topology_init(void)
{
int i;
for_each_possible_cpu(i) {
struct cpu *cpu = &per_cpu(cpu_data, i);
struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
cpu->hotpluggable = 1;
register_cpu(cpu, i);
}

6
arch/arm64/kernel/smp.c
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@ -39,6 +39,7 @@
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpu_ops.h>
#include <asm/mmu_context.h>
@ -154,6 +155,11 @@ asmlinkage void secondary_start_kernel(void)
if (cpu_ops[cpu]->cpu_postboot)
cpu_ops[cpu]->cpu_postboot();
/*
* Log the CPU info before it is marked online and might get read.
*/
cpuinfo_store_cpu();
/*
* Enable GIC and timers.
*/