xref: /openbmc/linux/arch/arm64/include/asm/cpu_ops.h (revision 58f7553fa424fd0fd74e8b796d50c66014cebebe)
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 necessary
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  int __init init_cpu_ops(int cpu);
59  extern const struct cpu_operations *get_cpu_ops(int cpu);
60  
61  static inline void __init init_bootcpu_ops(void)
62  {
63  	init_cpu_ops(0);
64  }
65  
66  #endif /* ifndef __ASM_CPU_OPS_H */
67