xref: /openbmc/linux/arch/arm64/include/asm/cpu_ops.h (revision b593bce5)
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_disable: Prepares a cpu to die. May fail for some mechanism-specific
27  * 		reason, which will cause the hot unplug to be aborted. Called
28  * 		from the cpu to be killed.
29  * @cpu_die:	Makes a cpu leave the kernel. Must not fail. Called from the
30  *		cpu being killed.
31  * @cpu_kill:  Ensures a cpu has left the kernel. Called from another cpu.
32  * @cpu_init_idle: Reads any data necessary to initialize CPU idle states for
33  *		   a proposed logical id.
34  * @cpu_suspend: Suspends a cpu and saves the required context. May fail owing
35  *               to wrong parameters or error conditions. Called from the
36  *               CPU being suspended. Must be called with IRQs disabled.
37  */
38 struct cpu_operations {
39 	const char	*name;
40 	int		(*cpu_init)(unsigned int);
41 	int		(*cpu_prepare)(unsigned int);
42 	int		(*cpu_boot)(unsigned int);
43 	void		(*cpu_postboot)(void);
44 #ifdef CONFIG_HOTPLUG_CPU
45 	int		(*cpu_disable)(unsigned int cpu);
46 	void		(*cpu_die)(unsigned int cpu);
47 	int		(*cpu_kill)(unsigned int cpu);
48 #endif
49 #ifdef CONFIG_CPU_IDLE
50 	int		(*cpu_init_idle)(unsigned int);
51 	int		(*cpu_suspend)(unsigned long);
52 #endif
53 };
54 
55 extern const struct cpu_operations *cpu_ops[NR_CPUS];
56 int __init cpu_read_ops(int cpu);
57 
58 static inline void __init cpu_read_bootcpu_ops(void)
59 {
60 	cpu_read_ops(0);
61 }
62 
63 #endif /* ifndef __ASM_CPU_OPS_H */
64