The suspend() hook in the cpuidle_ops struct is always called on the cpu entering idle, which means that the cpu parameter passed to the suspend hook always corresponds to the local cpu, making it somewhat redundant. This patch removes the logical cpu parameter from the ARM cpuidle_ops.suspend hook and updates all the existing kernel implementations to reflect this change. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Lina Iyer <lina.iyer@linaro.org> Tested-by: Lina Iyer <lina.iyer@linaro.org> Tested-by: Jisheng Zhang <jszhang@marvell.com> [psci] Cc: Lina Iyer <lina.iyer@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
152 lines
4.1 KiB
C
152 lines
4.1 KiB
C
/*
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* Copyright 2012 Linaro Ltd.
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*
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* The code contained herein is licensed under the GNU General Public
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* License. You may obtain a copy of the GNU General Public License
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* Version 2 or later at the following locations:
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*
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* http://www.opensource.org/licenses/gpl-license.html
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* http://www.gnu.org/copyleft/gpl.html
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*/
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#include <linux/cpuidle.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <asm/cpuidle.h>
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extern struct of_cpuidle_method __cpuidle_method_of_table[];
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static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
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__used __section(__cpuidle_method_of_table_end);
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static struct cpuidle_ops cpuidle_ops[NR_CPUS];
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/**
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* arm_cpuidle_simple_enter() - a wrapper to cpu_do_idle()
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* @dev: not used
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* @drv: not used
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* @index: not used
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*
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* A trivial wrapper to allow the cpu_do_idle function to be assigned as a
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* cpuidle callback by matching the function signature.
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*
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* Returns the index passed as parameter
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*/
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int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
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struct cpuidle_driver *drv, int index)
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{
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cpu_do_idle();
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return index;
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}
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/**
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* arm_cpuidle_suspend() - function to enter low power idle states
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* @index: an integer used as an identifier for the low level PM callbacks
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*
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* This function calls the underlying arch specific low level PM code as
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* registered at the init time.
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*
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* Returns -EOPNOTSUPP if no suspend callback is defined, the result of the
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* callback otherwise.
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*/
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int arm_cpuidle_suspend(int index)
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{
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int ret = -EOPNOTSUPP;
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int cpu = smp_processor_id();
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if (cpuidle_ops[cpu].suspend)
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ret = cpuidle_ops[cpu].suspend(index);
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return ret;
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}
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/**
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* arm_cpuidle_get_ops() - find a registered cpuidle_ops by name
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* @method: the method name
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*
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* Search in the __cpuidle_method_of_table array the cpuidle ops matching the
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* method name.
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*
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* Returns a struct cpuidle_ops pointer, NULL if not found.
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*/
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static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
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{
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struct of_cpuidle_method *m = __cpuidle_method_of_table;
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for (; m->method; m++)
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if (!strcmp(m->method, method))
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return m->ops;
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return NULL;
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}
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/**
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* arm_cpuidle_read_ops() - Initialize the cpuidle ops with the device tree
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* @dn: a pointer to a struct device node corresponding to a cpu node
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* @cpu: the cpu identifier
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*
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* Get the method name defined in the 'enable-method' property, retrieve the
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* associated cpuidle_ops and do a struct copy. This copy is needed because all
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* cpuidle_ops are tagged __initdata and will be unloaded after the init
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* process.
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*
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* Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
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* no cpuidle_ops is registered for the 'enable-method'.
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*/
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static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
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{
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const char *enable_method;
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struct cpuidle_ops *ops;
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enable_method = of_get_property(dn, "enable-method", NULL);
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if (!enable_method)
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return -ENOENT;
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ops = arm_cpuidle_get_ops(enable_method);
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if (!ops) {
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pr_warn("%s: unsupported enable-method property: %s\n",
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dn->full_name, enable_method);
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return -EOPNOTSUPP;
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}
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cpuidle_ops[cpu] = *ops; /* structure copy */
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pr_notice("cpuidle: enable-method property '%s'"
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" found operations\n", enable_method);
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return 0;
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}
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/**
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* arm_cpuidle_init() - Initialize cpuidle_ops for a specific cpu
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* @cpu: the cpu to be initialized
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*
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* Initialize the cpuidle ops with the device for the cpu and then call
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* the cpu's idle initialization callback. This may fail if the underlying HW
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* is not operational.
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*
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* Returns:
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* 0 on success,
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* -ENODEV if it fails to find the cpu node in the device tree,
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* -EOPNOTSUPP if it does not find a registered cpuidle_ops for this cpu,
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* -ENOENT if it fails to find an 'enable-method' property,
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* -ENXIO if the HW reports a failure or a misconfiguration,
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* -ENOMEM if the HW report an memory allocation failure
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*/
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int __init arm_cpuidle_init(int cpu)
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{
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struct device_node *cpu_node = of_cpu_device_node_get(cpu);
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int ret;
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if (!cpu_node)
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return -ENODEV;
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ret = arm_cpuidle_read_ops(cpu_node, cpu);
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if (!ret && cpuidle_ops[cpu].init)
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ret = cpuidle_ops[cpu].init(cpu_node, cpu);
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of_node_put(cpu_node);
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return ret;
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}
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