| Message ID | E1r0JLl-00CTxk-7O@rmk-PC.armlinux.org.uk (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | Initial cleanups for vCPU hotplug | expand |
On 11/7/23 18:30, Russell King (Oracle) 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> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > --- > 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(-) > > 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) > {
On 11/7/23 20:30, Russell King (Oracle) 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> > 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(-) > Reviewed-by: Gavin Shan <gshan@redhat.com>
On Tue, 07 Nov 2023 10:30:25 +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> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Given this series adds an arch_cpu_is_hotpluggable() callback we probably want something in this patch description to say why this isn't using that, but instead overriding arch_register_cpu() Jonathan > --- > 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(-) > > 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) > {
On Tue, 28 Nov 2023 15:08:54 +0000 Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote: > On Tue, 07 Nov 2023 10:30:25 +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> > > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> > > Given this series adds an arch_cpu_is_hotpluggable() callback we probably > want something in this patch description to say why this > isn't using that, but instead overriding arch_register_cpu() > As per comment on next patch I'm fine with this slight dance. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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) {