arch/arm64/include/asm/cpu_ops.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2013 ARM Ltd.
   4  */
   5 #ifndef __ASM_CPU_OPS_H
   6 #define __ASM_CPU_OPS_H
   7
   8 #include <linux/init.h>
   9 #include <linux/threads.h>
  10
  11 /**
  12  * struct cpu_operations - Callback operations for hotplugging CPUs.
  13  *
  14  * @name:       Name of the property as appears in a devicetree cpu node's
  15  *              enable-method property. On systems booting with ACPI, @name
  16  *              identifies the struct cpu_operations entry corresponding to
  17  *              the boot protocol specified in the ACPI MADT table.
  18  * @cpu_init:   Reads any data necessary for a specific enable-method for a
  19  *              proposed logical id.
  20  * @cpu_prepare: Early one-time preparation step for a cpu. If there is a
  21  *              mechanism for doing so, tests whether it is possible to boot
  22  *              the given CPU.
  23  * @cpu_boot:   Boots a cpu into the kernel.
  24  * @cpu_postboot: Optionally, perform any post-boot cleanup or necesary
  25  *              synchronisation. Called from the cpu being booted.
  26  * @cpu_can_disable: Determines whether a CPU can be disabled based on
  27  *              mechanism-specific information.
  28  * @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific
  29  *              reason, which will cause the hot unplug to be aborted. Called
  30  *              from the cpu to be killed.
  31  * @cpu_die:    Makes a cpu leave the kernel. Must not fail. Called from the
  32  *              cpu being killed.
  33  * @cpu_kill:  Ensures a cpu has left the kernel. Called from another cpu.
  34  * @cpu_init_idle: Reads any data necessary to initialize CPU idle states for
  35  *                 a proposed logical id.
  36  * @cpu_suspend: Suspends a cpu and saves the required context. May fail owing
  37  *               to wrong parameters or error conditions. Called from the
  38  *               CPU being suspended. Must be called with IRQs disabled.
  39  */
  40 struct cpu_operations {
  41         const char      *name;
  42         int             (*cpu_init)(unsigned int);
  43         int             (*cpu_prepare)(unsigned int);
  44         int             (*cpu_boot)(unsigned int);
  45         void            (*cpu_postboot)(void);
  46 #ifdef CONFIG_HOTPLUG_CPU
  47         bool            (*cpu_can_disable)(unsigned int cpu);
  48         int             (*cpu_disable)(unsigned int cpu);
  49         void            (*cpu_die)(unsigned int cpu);
  50         int             (*cpu_kill)(unsigned int cpu);
  51 #endif
  52 #ifdef CONFIG_CPU_IDLE
  53         int             (*cpu_init_idle)(unsigned int);
  54         int             (*cpu_suspend)(unsigned long);
  55 #endif
  56 };
  57
  58 extern const struct cpu_operations *cpu_ops[NR_CPUS];
  59 int __init cpu_read_ops(int cpu);
  60
  61 static inline void __init cpu_read_bootcpu_ops(void)
  62 {
  63         cpu_read_ops(0);
  64 }
  65
  66 #endif /* ifndef __ASM_CPU_OPS_H */