| Message ID | E1r0JLG-00CTx8-CG@rmk-PC.armlinux.org.uk (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
| Series | Initial cleanups for vCPU hotplug | expand |
On 11/7/23 18:29, Russell King (Oracle) wrote: > From: James Morse <james.morse@arm.com> > > Architectures often have extra per-cpu work that needs doing > before a CPU is registered, often to determine if a CPU is > hotpluggable. > > To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move > the cpu_register() call into arch_register_cpu(), which is made __weak > so architectures with extra work can override it. > This aligns with the way x86, ia64 and loongarch register hotplug CPUs > when they become present. > > Signed-off-by: James Morse <james.morse@arm.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > --- > Changes since RFC: > * Dropped __init from x86/ia64 arch_register_cpu() > Changes since RFC v2: > * Dropped unnecessary Loongarch asm/cpu.h changes > --- > drivers/base/cpu.c | 14 ++++++++++---- > include/linux/cpu.h | 4 ++++ > 2 files changed, 14 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c > index 34b48f660b6b..579064fda97b 100644 > --- a/drivers/base/cpu.c > +++ b/drivers/base/cpu.c > @@ -525,19 +525,25 @@ bool cpu_is_hotpluggable(unsigned int cpu) > EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); > > #ifdef CONFIG_GENERIC_CPU_DEVICES > -static DEFINE_PER_CPU(struct cpu, cpu_devices); > +DEFINE_PER_CPU(struct cpu, cpu_devices); > + > +int __weak arch_register_cpu(int cpu) > +{ > + return register_cpu(&per_cpu(cpu_devices, cpu), cpu); > +} > #endif > > static void __init cpu_dev_register_generic(void) > { > -#ifdef CONFIG_GENERIC_CPU_DEVICES > int i; > > + if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES)) > + return; > + > for_each_present_cpu(i) { > - if (register_cpu(&per_cpu(cpu_devices, i), i)) > + if (arch_register_cpu(i)) > panic("Failed to register CPU device"); > } > -#endif > } > > #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES > diff --git a/include/linux/cpu.h b/include/linux/cpu.h > index fc8094419084..1e982d63eae8 100644 > --- a/include/linux/cpu.h > +++ b/include/linux/cpu.h > @@ -88,6 +88,10 @@ extern ssize_t arch_cpu_probe(const char *, size_t); > extern ssize_t arch_cpu_release(const char *, size_t); > #endif > > +#ifdef CONFIG_GENERIC_CPU_DEVICES > +DECLARE_PER_CPU(struct cpu, cpu_devices); > +#endif > + > /* > * These states are not related to the core CPU hotplug mechanism. They are > * used by various (sub)architectures to track internal state
On 11/7/23 20:29, Russell King (Oracle) wrote: > From: James Morse <james.morse@arm.com> > > Architectures often have extra per-cpu work that needs doing > before a CPU is registered, often to determine if a CPU is > hotpluggable. > > To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move > the cpu_register() call into arch_register_cpu(), which is made __weak > so architectures with extra work can override it. > This aligns with the way x86, ia64 and loongarch register hotplug CPUs > when they become present. > > Signed-off-by: James Morse <james.morse@arm.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> > --- > Changes since RFC: > * Dropped __init from x86/ia64 arch_register_cpu() > Changes since RFC v2: > * Dropped unnecessary Loongarch asm/cpu.h changes > --- > drivers/base/cpu.c | 14 ++++++++++---- > include/linux/cpu.h | 4 ++++ > 2 files changed, 14 insertions(+), 4 deletions(-) > Reviewed-by: Gavin Shan <gshan@redhat.com>
On Tue, 07 Nov 2023 10:29:54 +0000 Russell King <rmk+kernel@armlinux.org.uk> wrote: > From: James Morse <james.morse@arm.com> > > Architectures often have extra per-cpu work that needs doing > before a CPU is registered, often to determine if a CPU is > hotpluggable. > > To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move > the cpu_register() call into arch_register_cpu(), which is made __weak > so architectures with extra work can override it. > This aligns with the way x86, ia64 and loongarch register hotplug CPUs > when they become present. > > Signed-off-by: James Morse <james.morse@arm.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 34b48f660b6b..579064fda97b 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -525,19 +525,25 @@ bool cpu_is_hotpluggable(unsigned int cpu) EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); #ifdef CONFIG_GENERIC_CPU_DEVICES -static DEFINE_PER_CPU(struct cpu, cpu_devices); +DEFINE_PER_CPU(struct cpu, cpu_devices); + +int __weak arch_register_cpu(int cpu) +{ + return register_cpu(&per_cpu(cpu_devices, cpu), cpu); +} #endif static void __init cpu_dev_register_generic(void) { -#ifdef CONFIG_GENERIC_CPU_DEVICES int i; + if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES)) + return; + for_each_present_cpu(i) { - if (register_cpu(&per_cpu(cpu_devices, i), i)) + if (arch_register_cpu(i)) panic("Failed to register CPU device"); } -#endif } #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES diff --git a/include/linux/cpu.h b/include/linux/cpu.h index fc8094419084..1e982d63eae8 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -88,6 +88,10 @@ extern ssize_t arch_cpu_probe(const char *, size_t); extern ssize_t arch_cpu_release(const char *, size_t); #endif +#ifdef CONFIG_GENERIC_CPU_DEVICES +DECLARE_PER_CPU(struct cpu, cpu_devices); +#endif + /* * These states are not related to the core CPU hotplug mechanism. They are * used by various (sub)architectures to track internal state