Commit 0949dd96 authored by James Morse's avatar James Morse Committed by Greg Kroah-Hartman
Browse files

drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden 



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: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarShaoqin Huang <shahuang@redhat.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Signed-off-by: default avatar"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1r5R3B-00Csz6-Uh@rmk-PC.armlinux.org.uk


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b0c69e12

drivers/base/cpu.c

+10 −4
Original line number Diff line number Diff line
@@ -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

include/linux/cpu.h

+4 −0
Original line number Diff line number Diff line
@@ -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