xref: /openbmc/linux/arch/arm64/include/asm/cpu_ops.h (revision 6d99a79c)
1 /*
2  * Copyright (C) 2013 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_CPU_OPS_H
17 #define __ASM_CPU_OPS_H
18 
19 #include <linux/init.h>
20 #include <linux/threads.h>
21 
22 /**
23  * struct cpu_operations - Callback operations for hotplugging CPUs.
24  *
25  * @name:	Name of the property as appears in a devicetree cpu node's
26  *		enable-method property. On systems booting with ACPI, @name
27  *		identifies the struct cpu_operations entry corresponding to
28  *		the boot protocol specified in the ACPI MADT table.
29  * @cpu_init:	Reads any data necessary for a specific enable-method for a
30  *		proposed logical id.
31  * @cpu_prepare: Early one-time preparation step for a cpu. If there is a
32  *		mechanism for doing so, tests whether it is possible to boot
33  *		the given CPU.
34  * @cpu_boot:	Boots a cpu into the kernel.
35  * @cpu_postboot: Optionally, perform any post-boot cleanup or necesary
36  *		synchronisation. Called from the cpu being booted.
37  * @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific
38  * 		reason, which will cause the hot unplug to be aborted. Called
39  * 		from the cpu to be killed.
40  * @cpu_die:	Makes a cpu leave the kernel. Must not fail. Called from the
41  *		cpu being killed.
42  * @cpu_kill:  Ensures a cpu has left the kernel. Called from another cpu.
43  * @cpu_init_idle: Reads any data necessary to initialize CPU idle states for
44  *		   a proposed logical id.
45  * @cpu_suspend: Suspends a cpu and saves the required context. May fail owing
46  *               to wrong parameters or error conditions. Called from the
47  *               CPU being suspended. Must be called with IRQs disabled.
48  */
49 struct cpu_operations {
50 	const char	*name;
51 	int		(*cpu_init)(unsigned int);
52 	int		(*cpu_prepare)(unsigned int);
53 	int		(*cpu_boot)(unsigned int);
54 	void		(*cpu_postboot)(void);
55 #ifdef CONFIG_HOTPLUG_CPU
56 	int		(*cpu_disable)(unsigned int cpu);
57 	void		(*cpu_die)(unsigned int cpu);
58 	int		(*cpu_kill)(unsigned int cpu);
59 #endif
60 #ifdef CONFIG_CPU_IDLE
61 	int		(*cpu_init_idle)(unsigned int);
62 	int		(*cpu_suspend)(unsigned long);
63 #endif
64 };
65 
66 extern const struct cpu_operations *cpu_ops[NR_CPUS];
67 int __init cpu_read_ops(int cpu);
68 
69 static inline void __init cpu_read_bootcpu_ops(void)
70 {
71 	cpu_read_ops(0);
72 }
73 
74 #endif /* ifndef __ASM_CPU_OPS_H */
75