linux_dsm_epyc7002/arch/arm64/include/asm/cpu_ops.h
Ashwin Chaugule c814ca029e ARM: Check if a CPU has gone offline
PSCIv0.2 adds a new function called AFFINITY_INFO, which
can be used to query if a specified CPU has actually gone
offline. Calling this function via cpu_kill ensures that
a CPU has quiesced after a call to cpu_die. This helps
prevent the CPU from doing arbitrary bad things when data
or instructions are clobbered (as happens with kexec)
in the window between a CPU announcing that it is dead
and said CPU leaving the kernel.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-15 10:16:30 -04:00

68 lines
2.5 KiB
C

/*
* Copyright (C) 2013 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CPU_OPS_H
#define __ASM_CPU_OPS_H
#include <linux/init.h>
#include <linux/threads.h>
struct device_node;
/**
* struct cpu_operations - Callback operations for hotplugging CPUs.
*
* @name: Name of the property as appears in a devicetree cpu node's
* enable-method property.
* @cpu_init: Reads any data necessary for a specific enable-method from the
* devicetree, for a given cpu node and proposed logical id.
* @cpu_prepare: Early one-time preparation step for a cpu. If there is a
* mechanism for doing so, tests whether it is possible to boot
* the given CPU.
* @cpu_boot: Boots a cpu into the kernel.
* @cpu_postboot: Optionally, perform any post-boot cleanup or necesary
* synchronisation. Called from the cpu being booted.
* @cpu_disable: Prepares a cpu to die. May fail for some mechanism-specific
* reason, which will cause the hot unplug to be aborted. Called
* from the cpu to be killed.
* @cpu_die: Makes a cpu leave the kernel. Must not fail. Called from the
* cpu being killed.
* @cpu_kill: Ensures a cpu has left the kernel. Called from another cpu.
* @cpu_suspend: Suspends a cpu and saves the required context. May fail owing
* to wrong parameters or error conditions. Called from the
* CPU being suspended. Must be called with IRQs disabled.
*/
struct cpu_operations {
const char *name;
int (*cpu_init)(struct device_node *, unsigned int);
int (*cpu_prepare)(unsigned int);
int (*cpu_boot)(unsigned int);
void (*cpu_postboot)(void);
#ifdef CONFIG_HOTPLUG_CPU
int (*cpu_disable)(unsigned int cpu);
void (*cpu_die)(unsigned int cpu);
int (*cpu_kill)(unsigned int cpu);
#endif
#ifdef CONFIG_ARM64_CPU_SUSPEND
int (*cpu_suspend)(unsigned long);
#endif
};
extern const struct cpu_operations *cpu_ops[NR_CPUS];
extern int __init cpu_read_ops(struct device_node *dn, int cpu);
extern void __init cpu_read_bootcpu_ops(void);
#endif /* ifndef __ASM_CPU_OPS_H */