| Message ID | E1r5R3b-00Csza-Ku@rmk-PC.armlinux.org.uk |
|---|---|
| State | New |
| Headers | show |
| Series | Initial cleanups for vCPU hotplug | expand |
On Tue, 21 Nov 2023 13:44:51 +0000 Russell King <rmk+kernel@armlinux.org.uk> wrote: > From: James Morse <james.morse@arm.com> > > 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>
On Tue, Nov 21, 2023 at 01:44:51PM +0000, Russell King wrote: > From: James Morse <james.morse@arm.com> > > 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> > --- > Changes since RFC v2: > * Add note about initialisation order change. > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/cpu.h | 1 - > arch/arm64/kernel/setup.c | 13 ++++--------- > 3 files changed, 5 insertions(+), 10 deletions(-) Acked-by: Will Deacon <will@kernel.org> Will
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b071a00425d..84bce830e365 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -132,6 +132,7 @@ 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 f3034099fd95..b1e43f56ee46 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 417a8a86b2db..165bd2c0dd5a 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -402,19 +402,14 @@ 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) {