Files
linux/arch/arm64/include/asm/cpu.h
James Morse 09e6b306f3 arm64: cpufeature: discover CPU support for MPAM
ARMv8.4 adds support for 'Memory Partitioning And Monitoring' (MPAM)
which describes an interface to cache and bandwidth controls wherever
they appear in the system.

Add support to detect MPAM. Like SVE, MPAM has an extra id register that
describes some more properties, including the virtualisation support,
which is optional. Detect this separately so we can detect
mismatched/insane systems, but still use MPAM on the host even if the
virtualisation support is missing.

MPAM needs enabling at the highest implemented exception level, otherwise
the register accesses trap. The 'enabled' flag is accessible to lower
exception levels, but its in a register that traps when MPAM isn't enabled.
The cpufeature 'matches' hook is extended to test this on one of the
CPUs, so that firmware can emulate MPAM as disabled if it is reserved
for use by secure world.

Secondary CPUs that appear late could trip cpufeature's 'lower safe'
behaviour after the MPAM properties have been advertised to user-space.
Add a verify call to ensure late secondaries match the existing CPUs.

(If you have a boot failure that bisects here its likely your CPUs
advertise MPAM in the id registers, but firmware failed to either enable
or MPAM, or emulate the trap as if it were disabled)

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241030160317.2528209-4-joey.gouly@arm.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 18:09:38 +00:00

82 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014 ARM Ltd.
*/
#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_32bit {
u32 reg_id_dfr0;
u32 reg_id_dfr1;
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_isar6;
u32 reg_id_mmfr0;
u32 reg_id_mmfr1;
u32 reg_id_mmfr2;
u32 reg_id_mmfr3;
u32 reg_id_mmfr4;
u32 reg_id_mmfr5;
u32 reg_id_pfr0;
u32 reg_id_pfr1;
u32 reg_id_pfr2;
u32 reg_mvfr0;
u32 reg_mvfr1;
u32 reg_mvfr2;
};
struct cpuinfo_arm64 {
struct kobject kobj;
u64 reg_ctr;
u64 reg_cntfrq;
u64 reg_dczid;
u64 reg_midr;
u64 reg_revidr;
u64 reg_gmid;
u64 reg_smidr;
u64 reg_mpamidr;
u64 reg_id_aa64dfr0;
u64 reg_id_aa64dfr1;
u64 reg_id_aa64isar0;
u64 reg_id_aa64isar1;
u64 reg_id_aa64isar2;
u64 reg_id_aa64isar3;
u64 reg_id_aa64mmfr0;
u64 reg_id_aa64mmfr1;
u64 reg_id_aa64mmfr2;
u64 reg_id_aa64mmfr3;
u64 reg_id_aa64mmfr4;
u64 reg_id_aa64pfr0;
u64 reg_id_aa64pfr1;
u64 reg_id_aa64pfr2;
u64 reg_id_aa64zfr0;
u64 reg_id_aa64smfr0;
u64 reg_id_aa64fpfr0;
struct cpuinfo_32bit aarch32;
};
DECLARE_PER_CPU(struct cpuinfo_arm64, cpu_data);
void cpuinfo_store_cpu(void);
void __init cpuinfo_store_boot_cpu(void);
void __init init_cpu_features(struct cpuinfo_arm64 *info);
void update_cpu_features(int cpu, struct cpuinfo_arm64 *info,
struct cpuinfo_arm64 *boot);
#endif /* __ASM_CPU_H */