From: James Morse james.morse@arm.com
mainline inclusion from mainline-v6.8-rc1 commit d127db1a23c94a876557b5bf8ca8bea49e8debb6 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
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To allow ACPI's _STA value to hide CPUs that are present, but not available to online right now due to VMM or firmware policy, the register_cpu() call needs to be made by the ACPI machinery when ACPI is in use. This allows it to hide CPUs that are unavailable from sysfs.
Switching to GENERIC_CPU_DEVICES is an intermediate step to allow all five ACPI architectures to be modified at once.
Switch over to GENERIC_CPU_DEVICES, and provide an arch_register_cpu() that populates the hotpluggable flag. arch_register_cpu() is also the interface the ACPI machinery expects.
The struct cpu in struct cpuinfo_arm64 is never used directly, remove it to use the one GENERIC_CPU_DEVICES provides.
This changes the CPUs visible in sysfs from possible to present, but on arm64 smp_prepare_cpus() ensures these are the same.
This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse james.morse@arm.com Reviewed-by: "Russell King (Oracle)" rmk+kernel@armlinux.org.uk Reviewed-by: Shaoqin Huang shahuang@redhat.com Reviewed-by: Gavin Shan gshan@redhat.com Signed-off-by: "Russell King (Oracle)" rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/E1r5R3b-00Csza-Ku@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: liwei liwei728@huawei.com --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/cpu.h | 1 - arch/arm64/kernel/setup.c | 13 ++++--------- 3 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9568049f36e3..604a63437751 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -133,6 +133,7 @@ config ARM64 select GENERIC_ARCH_TOPOLOGY select GENERIC_CLOCKEVENTS_BROADCAST select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_DEVICES select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_IDLE_POLL_SETUP diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h index e749838b9c5d..887bd0d992bb 100644 --- a/arch/arm64/include/asm/cpu.h +++ b/arch/arm64/include/asm/cpu.h @@ -38,7 +38,6 @@ struct cpuinfo_32bit { };
struct cpuinfo_arm64 { - struct cpu cpu; struct kobject kobj; u64 reg_ctr; u64 reg_cntfrq; diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 645034e52496..7f661a89a51d 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -451,19 +451,14 @@ static inline bool cpu_can_disable(unsigned int cpu) return false; }
-static int __init topology_init(void) +int arch_register_cpu(int num) { - int i; + struct cpu *cpu = &per_cpu(cpu_devices, num);
- for_each_possible_cpu(i) { - struct cpu *cpu = &per_cpu(cpu_data.cpu, i); - cpu->hotpluggable = cpu_can_disable(i); - register_cpu(cpu, i); - } + cpu->hotpluggable = cpu_can_disable(num);
- return 0; + return register_cpu(cpu, num); } -subsys_initcall(topology_init);
static void dump_kernel_offset(void) {