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Commit 9327e2c6 authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
Browse files

arm64: add CPU_HOTPLUG infrastructure 



This patch adds the basic infrastructure necessary to support
CPU_HOTPLUG on arm64, based on the arm implementation. Actual hotplug
support will depend on an implementation's cpu_operations (e.g. PSCI).

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent e8765b26

arch/arm64/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -161,6 +161,13 @@ config NR_CPUS 
	default "8" if ARCH_XGENE

	default "4"



config HOTPLUG_CPU

	bool "Support for hot-pluggable CPUs"

	depends on SMP

	help

	  Say Y here to experiment with turning CPUs off and on.  CPUs

	  can be controlled through /sys/devices/system/cpu.



source kernel/Kconfig.preempt



config HZ

arch/arm64/include/asm/cpu_ops.h

+9 −0
Original line number Diff line number Diff line
@@ -34,6 +34,11 @@ struct device_node; 
 * @cpu_boot:	Boots a cpu into the kernel.

 * @cpu_postboot: Optionally, perform any post-boot cleanup or necesary

 *		synchronisation. Called from the cpu being booted.

 * @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific

 * 		reason, which will cause the hot unplug to be aborted. Called

 * 		from the cpu to be killed.

 * @cpu_die:	Makes a cpu leave the kernel. Must not fail. Called from the

 *		cpu being killed.

 */

struct cpu_operations {

	const char	*name;
@@ -41,6 +46,10 @@ struct cpu_operations { 
	int		(*cpu_prepare)(unsigned int);

	int		(*cpu_boot)(unsigned int);

	void		(*cpu_postboot)(void);

#ifdef CONFIG_HOTPLUG_CPU

	int		(*cpu_disable)(unsigned int cpu);

	void		(*cpu_die)(unsigned int cpu);

#endif

};



extern const struct cpu_operations *cpu_ops[NR_CPUS];

arch/arm64/include/asm/irq.h

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <asm-generic/irq.h>



extern void (*handle_arch_irq)(struct pt_regs *);

extern void migrate_irqs(void);

extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));



#endif

arch/arm64/include/asm/smp.h

+5 −0
Original line number Diff line number Diff line
@@ -65,4 +65,9 @@ extern void secondary_entry(void); 
extern void arch_send_call_function_single_ipi(int cpu);

extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);



extern int __cpu_disable(void);



extern void __cpu_die(unsigned int cpu);

extern void cpu_die(void);



#endif /* ifndef __ASM_SMP_H */

arch/arm64/kernel/cputable.c

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 


extern unsigned long __cpu_setup(void);



struct cpu_info __initdata cpu_table[] = {

struct cpu_info cpu_table[] = {

	{

		.cpu_id_val	= 0x000f0000,

		.cpu_id_mask	= 0x000f0000,