arch/arm64/include/asm/cpu_ops.h

   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 */