linux/arch/arm64/include/asm/cpu_ops.h
Lorenzo Pieralisi af3cfdbf56 arm64: kernel: remove ARM64_CPU_SUSPEND config option
ARM64_CPU_SUSPEND config option was introduced to make code providing
context save/restore selectable only on platforms requiring power
management capabilities.

Currently ARM64_CPU_SUSPEND depends on the PM_SLEEP config option which
in turn is set by the SUSPEND config option.

The introduction of CPU_IDLE for arm64 requires that code configured
by ARM64_CPU_SUSPEND (context save/restore) should be compiled in
in order to enable the CPU idle driver to rely on CPU operations
carrying out context save/restore.

The ARM64_CPUIDLE config option (ARM64 generic idle driver) is therefore
forced to select ARM64_CPU_SUSPEND, even if there may be (ie PM_SLEEP)
failed dependencies, which is not a clean way of handling the kernel
configuration option.

For these reasons, this patch removes the ARM64_CPU_SUSPEND config option
and makes the context save/restore dependent on CPU_PM, which is selected
whenever either SUSPEND or CPU_IDLE are configured, cleaning up dependencies
in the process.

This way, code previously configured through ARM64_CPU_SUSPEND is
compiled in whenever a power management subsystem requires it to be
present in the kernel (SUSPEND || CPU_IDLE), which is the behaviour
expected on ARM64 kernels.

The cpu_suspend and cpu_init_idle CPU operations are added only if
CPU_IDLE is selected, since they are CPU_IDLE specific methods and
should be grouped and defined accordingly.

PSCI CPU operations are updated to reflect the introduced changes.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-27 11:35:33 +00:00

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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_init_idle: Reads any data necessary to initialize CPU idle states from
* devicetree, for a given cpu node and proposed logical id.
* @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_CPU_IDLE
int (*cpu_init_idle)(struct device_node *, unsigned int);
int (*cpu_suspend)(unsigned long);
#endif
};
extern const struct cpu_operations *cpu_ops[NR_CPUS];
int __init cpu_read_ops(struct device_node *dn, int cpu);
void __init cpu_read_bootcpu_ops(void);
#endif /* ifndef __ASM_CPU_OPS_H */