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