arm64: cpuinfo: record cpu system register values

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>

diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
new file mode 100644 (file)
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 cdaedad3afe51645fc4f4b79e44ccb1728d6fdf2..27c72ef4fd7a1725432ae9c18f35096beb14065d 100644 (file)
--- 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 (file)
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 46d1125571f6ca0e0ebaad6e9e2966bdabe3df7b..edb146d0185740b18de7d7cd365ae5d01ea1cbdc 100644 (file)
--- 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 40f38f46c8e0ad6ca8fb375fb35554ebd7a1a0f1..3e2f5ebbf63eb7cfe57834f63d5d0ffb47598818 100644 (file)
--- 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>
@@ -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.
         */