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linux-sg2042/arch/arm64/kernel/cpuidle.c

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arm64: kernel: introduce cpu_init_idle CPU operation The CPUidle subsystem on ARM64 machines requires the idle states implementation back-end to initialize idle states parameter upon boot. This patch adds a hook in the CPU operations structure that should be initialized by the CPU operations back-end in order to provide a function that initializes cpu idle states. This patch also adds the infrastructure to arm64 kernel required to export the CPU operations based initialization interface, so that drivers (ie CPUidle) can use it when they are initialized at probe time. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-17 17:30:07 +08:00
/*
* ARM64 CPU idle arch support
*
* Copyright (C) 2014 ARM Ltd.
* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
*
* 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.
*/
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/cpuidle.h>
#include <asm/cpu_ops.h>
ARM64: cpuidle: Rename cpu_init_idle to a common function name With this change the cpuidle-arm64.c file calls the same function name for both ARM and ARM64. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Rob Herring <robherring2@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2015-02-02 23:32:46 +08:00
int arm_cpuidle_init(unsigned int cpu)
arm64: kernel: introduce cpu_init_idle CPU operation The CPUidle subsystem on ARM64 machines requires the idle states implementation back-end to initialize idle states parameter upon boot. This patch adds a hook in the CPU operations structure that should be initialized by the CPU operations back-end in order to provide a function that initializes cpu idle states. This patch also adds the infrastructure to arm64 kernel required to export the CPU operations based initialization interface, so that drivers (ie CPUidle) can use it when they are initialized at probe time. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-17 17:30:07 +08:00
{
int ret = -EOPNOTSUPP;
if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle)
ARM64: kernel: make cpu_ops hooks DT agnostic ARM64 CPU operations such as cpu_init and cpu_init_idle take a struct device_node pointer as a parameter, which corresponds to the device tree node of the logical cpu on which the operation has to be applied. With the advent of ACPI on arm64, where MADT static table entries are used to initialize cpus, the device tree node parameter in cpu_ops hooks become useless when booting with ACPI, since in that case cpu device tree nodes are not present and can not be used for cpu initialization. The current cpu_init hook requires a struct device_node pointer parameter because it is called while parsing the device tree to initialize CPUs, when the cpu_logical_map (that is used to match a cpu node reg property to a device tree node) for a given logical cpu id is not set up yet. This means that the cpu_init hook cannot rely on the of_get_cpu_node function to retrieve the device tree node corresponding to the logical cpu id passed in as parameter, so the cpu device tree node must be passed in as a parameter to fix this catch-22 dependency cycle. This patch reshuffles the cpu_logical_map initialization code so that the cpu_init cpu_ops hook can safely use the of_get_cpu_node function to retrieve the cpu device tree node, removing the need for the device tree node pointer parameter. In the process, the patch removes device tree node parameters from all cpu_ops hooks, in preparation for SMP DT/ACPI cpus initialization consolidation. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Hanjun Guo <hanjun.guo@linaro.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Mark Rutland <mark.rutland@arm.com> [DT] Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-05-13 21:12:46 +08:00
ret = cpu_ops[cpu]->cpu_init_idle(cpu);
arm64: kernel: introduce cpu_init_idle CPU operation The CPUidle subsystem on ARM64 machines requires the idle states implementation back-end to initialize idle states parameter upon boot. This patch adds a hook in the CPU operations structure that should be initialized by the CPU operations back-end in order to provide a function that initializes cpu idle states. This patch also adds the infrastructure to arm64 kernel required to export the CPU operations based initialization interface, so that drivers (ie CPUidle) can use it when they are initialized at probe time. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-17 17:30:07 +08:00
return ret;
}
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 02:33:44 +08:00
/**
* cpu_suspend() - function to enter a low-power idle state
* @arg: argument to pass to CPU suspend operations
*
* Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
* operations back-end error code otherwise.
*/
int cpu_suspend(unsigned long arg)
{
int cpu = smp_processor_id();
/*
* If cpu_ops have not been registered or suspend
* has not been initialized, cpu_suspend call fails early.
*/
if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
return -EOPNOTSUPP;
return cpu_ops[cpu]->cpu_suspend(arg);
}