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>

1 files changed, 59 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
new file mode 100644
index 000000000000..056443086019
--- /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 */