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feb70af0e3
The syscore device PM flag used to mark the devices (belonging to PM domains) that should never be turned off, except for the system core (syscore) suspend/hibernation and resume stages, need not be accessed by the runtime PM core functions, because all of the devices it is set for need to be marked as "irq safe" anyway and are protected from being turned off by runtime PM by ensuring that their usage counters are always set. For this reason, make the syscore flag system-wide PM-specific and simplify the code used for manipulating it, because it need not acquire the device's power.lock any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
86 lines
1.8 KiB
C
86 lines
1.8 KiB
C
/*
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* drivers/base/power/common.c - Common device power management code.
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*
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* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/pm_clock.h>
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/**
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* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
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* @dev: Device to handle.
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*
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* If power.subsys_data is NULL, point it to a new object, otherwise increment
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* its reference counter. Return 1 if a new object has been created, otherwise
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* return 0 or error code.
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*/
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int dev_pm_get_subsys_data(struct device *dev)
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{
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struct pm_subsys_data *psd;
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psd = kzalloc(sizeof(*psd), GFP_KERNEL);
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if (!psd)
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return -ENOMEM;
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spin_lock_irq(&dev->power.lock);
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if (dev->power.subsys_data) {
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dev->power.subsys_data->refcount++;
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} else {
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spin_lock_init(&psd->lock);
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psd->refcount = 1;
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dev->power.subsys_data = psd;
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pm_clk_init(dev);
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psd = NULL;
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}
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spin_unlock_irq(&dev->power.lock);
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/* kfree() verifies that its argument is nonzero. */
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kfree(psd);
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return 0;
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}
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EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
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/**
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* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
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* @dev: Device to handle.
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*
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* If the reference counter of power.subsys_data is zero after dropping the
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* reference, power.subsys_data is removed. Return 1 if that happens or 0
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* otherwise.
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*/
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int dev_pm_put_subsys_data(struct device *dev)
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{
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struct pm_subsys_data *psd;
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int ret = 0;
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spin_lock_irq(&dev->power.lock);
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psd = dev_to_psd(dev);
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if (!psd) {
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ret = -EINVAL;
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goto out;
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}
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if (--psd->refcount == 0) {
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dev->power.subsys_data = NULL;
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kfree(psd);
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ret = 1;
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}
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out:
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spin_unlock_irq(&dev->power.lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
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