[PATCHv4 2/5] arm64: cpuinfo: record cpu system register values
Mark Rutland
mark.rutland at arm.com
Wed Jul 16 08:32:44 PDT 2014
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 at arm.com>
Cc: Will Deacon <will.deacon at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
---
arch/arm64/include/asm/cpu.h | 59 +++++++++++++++++++++++++++++++++++
arch/arm64/kernel/Makefile | 3 +-
arch/arm64/kernel/cpuinfo.c | 73 ++++++++++++++++++++++++++++++++++++++++++++
arch/arm64/kernel/setup.c | 7 +++--
arch/arm64/kernel/smp.c | 6 ++++
5 files changed, 144 insertions(+), 4 deletions(-)
create mode 100644 arch/arm64/include/asm/cpu.h
create mode 100644 arch/arm64/kernel/cpuinfo.c
diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
new file mode 100644
index 0000000..0564430
--- /dev/null
+++ b/arch/arm64/include/asm/cpu.h
@@ -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 */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index cdaedad..27c72ef 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -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
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
new file mode 100644
index 0000000..1f350fe
--- /dev/null
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -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;
+}
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 46d1125..edb146d 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -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);
}
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 40f38f4..3e2f5eb 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -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>
@@ -155,6 +156,11 @@ asmlinkage void secondary_start_kernel(void)
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.
*/
notify_cpu_starting(cpu);
--
1.9.1
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