mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 22:06:49 +07:00
778935778c
Further testing with false negatives suppressed by commit 293e2421fe
("rcu: Remove superfluous versions of rcu_read_lock_sched_held()")
identified a few more unprotected uses of RCU from the idle loop.
Because RCU actively ignores idle-loop code (for energy-efficiency
reasons, among other things), using RCU from the idle loop can result
in too-short grace periods, in turn resulting in arbitrary misbehavior.
The affected function is rpm_suspend().
The resulting lockdep-RCU splat is as follows:
------------------------------------------------------------------------
Warning from omap3
===============================
[ INFO: suspicious RCU usage. ]
4.6.0-rc5-next-20160426+ #1112 Not tainted
-------------------------------
include/trace/events/rpm.h:63 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
1 lock held by swapper/0/0:
#0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052ee24>] __pm_runtime_suspend+0x54/0x84
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112
Hardware name: Generic OMAP36xx (Flattened Device Tree)
[<c0110308>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14)
[<c010c3a8>] (show_stack) from [<c047fec8>] (dump_stack+0xb0/0xe4)
[<c047fec8>] (dump_stack) from [<c052d7b4>] (rpm_suspend+0x604/0x7e4)
[<c052d7b4>] (rpm_suspend) from [<c052ee34>] (__pm_runtime_suspend+0x64/0x84)
[<c052ee34>] (__pm_runtime_suspend) from [<c04bf3bc>] (omap2_gpio_prepare_for_idle+0x5c/0x70)
[<c04bf3bc>] (omap2_gpio_prepare_for_idle) from [<c01255e8>] (omap_sram_idle+0x140/0x244)
[<c01255e8>] (omap_sram_idle) from [<c0126b48>] (omap3_enter_idle_bm+0xfc/0x1ec)
[<c0126b48>] (omap3_enter_idle_bm) from [<c0601db8>] (cpuidle_enter_state+0x80/0x3d4)
[<c0601db8>] (cpuidle_enter_state) from [<c0183c74>] (cpu_startup_entry+0x198/0x3a0)
[<c0183c74>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8)
[<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c)
------------------------------------------------------------------------
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1532 lines
42 KiB
C
1532 lines
42 KiB
C
/*
|
|
* drivers/base/power/runtime.c - Helper functions for device runtime PM
|
|
*
|
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* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
|
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* Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
|
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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/sched.h>
|
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#include <linux/export.h>
|
|
#include <linux/pm_runtime.h>
|
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#include <linux/pm_wakeirq.h>
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#include <trace/events/rpm.h>
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#include "power.h"
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|
|
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typedef int (*pm_callback_t)(struct device *);
|
|
|
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static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset)
|
|
{
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pm_callback_t cb;
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const struct dev_pm_ops *ops;
|
|
|
|
if (dev->pm_domain)
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ops = &dev->pm_domain->ops;
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else if (dev->type && dev->type->pm)
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ops = dev->type->pm;
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else if (dev->class && dev->class->pm)
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ops = dev->class->pm;
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else if (dev->bus && dev->bus->pm)
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ops = dev->bus->pm;
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else
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ops = NULL;
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if (ops)
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cb = *(pm_callback_t *)((void *)ops + cb_offset);
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else
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cb = NULL;
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if (!cb && dev->driver && dev->driver->pm)
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cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset);
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return cb;
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}
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#define RPM_GET_CALLBACK(dev, callback) \
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__rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback))
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static int rpm_resume(struct device *dev, int rpmflags);
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static int rpm_suspend(struct device *dev, int rpmflags);
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/**
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* update_pm_runtime_accounting - Update the time accounting of power states
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* @dev: Device to update the accounting for
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*
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* In order to be able to have time accounting of the various power states
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* (as used by programs such as PowerTOP to show the effectiveness of runtime
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* PM), we need to track the time spent in each state.
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* update_pm_runtime_accounting must be called each time before the
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* runtime_status field is updated, to account the time in the old state
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* correctly.
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*/
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void update_pm_runtime_accounting(struct device *dev)
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{
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unsigned long now = jiffies;
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unsigned long delta;
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delta = now - dev->power.accounting_timestamp;
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dev->power.accounting_timestamp = now;
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if (dev->power.disable_depth > 0)
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return;
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if (dev->power.runtime_status == RPM_SUSPENDED)
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dev->power.suspended_jiffies += delta;
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else
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dev->power.active_jiffies += delta;
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}
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static void __update_runtime_status(struct device *dev, enum rpm_status status)
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{
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update_pm_runtime_accounting(dev);
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dev->power.runtime_status = status;
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}
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/**
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* pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
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* @dev: Device to handle.
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*/
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static void pm_runtime_deactivate_timer(struct device *dev)
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{
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if (dev->power.timer_expires > 0) {
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del_timer(&dev->power.suspend_timer);
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dev->power.timer_expires = 0;
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}
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}
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/**
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* pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
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* @dev: Device to handle.
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*/
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static void pm_runtime_cancel_pending(struct device *dev)
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|
{
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pm_runtime_deactivate_timer(dev);
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/*
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* In case there's a request pending, make sure its work function will
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* return without doing anything.
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*/
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dev->power.request = RPM_REQ_NONE;
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}
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/*
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* pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
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* @dev: Device to handle.
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*
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* Compute the autosuspend-delay expiration time based on the device's
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* power.last_busy time. If the delay has already expired or is disabled
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* (negative) or the power.use_autosuspend flag isn't set, return 0.
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* Otherwise return the expiration time in jiffies (adjusted to be nonzero).
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*
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* This function may be called either with or without dev->power.lock held.
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* Either way it can be racy, since power.last_busy may be updated at any time.
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*/
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unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
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{
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int autosuspend_delay;
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long elapsed;
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unsigned long last_busy;
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unsigned long expires = 0;
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if (!dev->power.use_autosuspend)
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goto out;
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autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
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if (autosuspend_delay < 0)
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goto out;
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last_busy = ACCESS_ONCE(dev->power.last_busy);
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elapsed = jiffies - last_busy;
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if (elapsed < 0)
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goto out; /* jiffies has wrapped around. */
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/*
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* If the autosuspend_delay is >= 1 second, align the timer by rounding
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* up to the nearest second.
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*/
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expires = last_busy + msecs_to_jiffies(autosuspend_delay);
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if (autosuspend_delay >= 1000)
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expires = round_jiffies(expires);
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expires += !expires;
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if (elapsed >= expires - last_busy)
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expires = 0; /* Already expired. */
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out:
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return expires;
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}
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EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
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static int dev_memalloc_noio(struct device *dev, void *data)
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{
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return dev->power.memalloc_noio;
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}
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/*
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* pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
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* @dev: Device to handle.
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* @enable: True for setting the flag and False for clearing the flag.
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*
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* Set the flag for all devices in the path from the device to the
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* root device in the device tree if @enable is true, otherwise clear
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* the flag for devices in the path whose siblings don't set the flag.
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*
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* The function should only be called by block device, or network
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* device driver for solving the deadlock problem during runtime
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* resume/suspend:
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*
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* If memory allocation with GFP_KERNEL is called inside runtime
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* resume/suspend callback of any one of its ancestors(or the
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* block device itself), the deadlock may be triggered inside the
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* memory allocation since it might not complete until the block
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* device becomes active and the involed page I/O finishes. The
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* situation is pointed out first by Alan Stern. Network device
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* are involved in iSCSI kind of situation.
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*
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* The lock of dev_hotplug_mutex is held in the function for handling
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* hotplug race because pm_runtime_set_memalloc_noio() may be called
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* in async probe().
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*
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* The function should be called between device_add() and device_del()
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* on the affected device(block/network device).
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*/
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void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
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{
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static DEFINE_MUTEX(dev_hotplug_mutex);
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mutex_lock(&dev_hotplug_mutex);
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for (;;) {
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bool enabled;
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/* hold power lock since bitfield is not SMP-safe. */
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spin_lock_irq(&dev->power.lock);
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enabled = dev->power.memalloc_noio;
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dev->power.memalloc_noio = enable;
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spin_unlock_irq(&dev->power.lock);
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/*
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* not need to enable ancestors any more if the device
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* has been enabled.
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*/
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if (enabled && enable)
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break;
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dev = dev->parent;
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/*
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* clear flag of the parent device only if all the
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* children don't set the flag because ancestor's
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* flag was set by any one of the descendants.
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*/
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if (!dev || (!enable &&
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device_for_each_child(dev, NULL,
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dev_memalloc_noio)))
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break;
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}
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mutex_unlock(&dev_hotplug_mutex);
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}
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EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
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/**
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* rpm_check_suspend_allowed - Test whether a device may be suspended.
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* @dev: Device to test.
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*/
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static int rpm_check_suspend_allowed(struct device *dev)
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{
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int retval = 0;
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if (dev->power.runtime_error)
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retval = -EINVAL;
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else if (dev->power.disable_depth > 0)
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retval = -EACCES;
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else if (atomic_read(&dev->power.usage_count) > 0)
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retval = -EAGAIN;
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else if (!pm_children_suspended(dev))
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retval = -EBUSY;
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/* Pending resume requests take precedence over suspends. */
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else if ((dev->power.deferred_resume
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&& dev->power.runtime_status == RPM_SUSPENDING)
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|| (dev->power.request_pending
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&& dev->power.request == RPM_REQ_RESUME))
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retval = -EAGAIN;
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else if (__dev_pm_qos_read_value(dev) < 0)
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retval = -EPERM;
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else if (dev->power.runtime_status == RPM_SUSPENDED)
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retval = 1;
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return retval;
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}
|
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/**
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* __rpm_callback - Run a given runtime PM callback for a given device.
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|
* @cb: Runtime PM callback to run.
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|
* @dev: Device to run the callback for.
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*/
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static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
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__releases(&dev->power.lock) __acquires(&dev->power.lock)
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{
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int retval;
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|
|
|
if (dev->power.irq_safe)
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|
spin_unlock(&dev->power.lock);
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else
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spin_unlock_irq(&dev->power.lock);
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|
retval = cb(dev);
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|
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if (dev->power.irq_safe)
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spin_lock(&dev->power.lock);
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|
else
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spin_lock_irq(&dev->power.lock);
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return retval;
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}
|
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|
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/**
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* rpm_idle - Notify device bus type if the device can be suspended.
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* @dev: Device to notify the bus type about.
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* @rpmflags: Flag bits.
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*
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* Check if the device's runtime PM status allows it to be suspended. If
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* another idle notification has been started earlier, return immediately. If
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* the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
|
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* run the ->runtime_idle() callback directly. If the ->runtime_idle callback
|
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* doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
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*
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|
* This function must be called under dev->power.lock with interrupts disabled.
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*/
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static int rpm_idle(struct device *dev, int rpmflags)
|
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{
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int (*callback)(struct device *);
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int retval;
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|
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trace_rpm_idle_rcuidle(dev, rpmflags);
|
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retval = rpm_check_suspend_allowed(dev);
|
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if (retval < 0)
|
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; /* Conditions are wrong. */
|
|
|
|
/* Idle notifications are allowed only in the RPM_ACTIVE state. */
|
|
else if (dev->power.runtime_status != RPM_ACTIVE)
|
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retval = -EAGAIN;
|
|
|
|
/*
|
|
* Any pending request other than an idle notification takes
|
|
* precedence over us, except that the timer may be running.
|
|
*/
|
|
else if (dev->power.request_pending &&
|
|
dev->power.request > RPM_REQ_IDLE)
|
|
retval = -EAGAIN;
|
|
|
|
/* Act as though RPM_NOWAIT is always set. */
|
|
else if (dev->power.idle_notification)
|
|
retval = -EINPROGRESS;
|
|
if (retval)
|
|
goto out;
|
|
|
|
/* Pending requests need to be canceled. */
|
|
dev->power.request = RPM_REQ_NONE;
|
|
|
|
if (dev->power.no_callbacks)
|
|
goto out;
|
|
|
|
/* Carry out an asynchronous or a synchronous idle notification. */
|
|
if (rpmflags & RPM_ASYNC) {
|
|
dev->power.request = RPM_REQ_IDLE;
|
|
if (!dev->power.request_pending) {
|
|
dev->power.request_pending = true;
|
|
queue_work(pm_wq, &dev->power.work);
|
|
}
|
|
trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
|
|
return 0;
|
|
}
|
|
|
|
dev->power.idle_notification = true;
|
|
|
|
callback = RPM_GET_CALLBACK(dev, runtime_idle);
|
|
|
|
if (callback)
|
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retval = __rpm_callback(callback, dev);
|
|
|
|
dev->power.idle_notification = false;
|
|
wake_up_all(&dev->power.wait_queue);
|
|
|
|
out:
|
|
trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
|
|
return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
|
|
}
|
|
|
|
/**
|
|
* rpm_callback - Run a given runtime PM callback for a given device.
|
|
* @cb: Runtime PM callback to run.
|
|
* @dev: Device to run the callback for.
|
|
*/
|
|
static int rpm_callback(int (*cb)(struct device *), struct device *dev)
|
|
{
|
|
int retval;
|
|
|
|
if (!cb)
|
|
return -ENOSYS;
|
|
|
|
if (dev->power.memalloc_noio) {
|
|
unsigned int noio_flag;
|
|
|
|
/*
|
|
* Deadlock might be caused if memory allocation with
|
|
* GFP_KERNEL happens inside runtime_suspend and
|
|
* runtime_resume callbacks of one block device's
|
|
* ancestor or the block device itself. Network
|
|
* device might be thought as part of iSCSI block
|
|
* device, so network device and its ancestor should
|
|
* be marked as memalloc_noio too.
|
|
*/
|
|
noio_flag = memalloc_noio_save();
|
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retval = __rpm_callback(cb, dev);
|
|
memalloc_noio_restore(noio_flag);
|
|
} else {
|
|
retval = __rpm_callback(cb, dev);
|
|
}
|
|
|
|
dev->power.runtime_error = retval;
|
|
return retval != -EACCES ? retval : -EIO;
|
|
}
|
|
|
|
/**
|
|
* rpm_suspend - Carry out runtime suspend of given device.
|
|
* @dev: Device to suspend.
|
|
* @rpmflags: Flag bits.
|
|
*
|
|
* Check if the device's runtime PM status allows it to be suspended.
|
|
* Cancel a pending idle notification, autosuspend or suspend. If
|
|
* another suspend has been started earlier, either return immediately
|
|
* or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
|
|
* flags. If the RPM_ASYNC flag is set then queue a suspend request;
|
|
* otherwise run the ->runtime_suspend() callback directly. When
|
|
* ->runtime_suspend succeeded, if a deferred resume was requested while
|
|
* the callback was running then carry it out, otherwise send an idle
|
|
* notification for its parent (if the suspend succeeded and both
|
|
* ignore_children of parent->power and irq_safe of dev->power are not set).
|
|
* If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
|
|
* flag is set and the next autosuspend-delay expiration time is in the
|
|
* future, schedule another autosuspend attempt.
|
|
*
|
|
* This function must be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static int rpm_suspend(struct device *dev, int rpmflags)
|
|
__releases(&dev->power.lock) __acquires(&dev->power.lock)
|
|
{
|
|
int (*callback)(struct device *);
|
|
struct device *parent = NULL;
|
|
int retval;
|
|
|
|
trace_rpm_suspend_rcuidle(dev, rpmflags);
|
|
|
|
repeat:
|
|
retval = rpm_check_suspend_allowed(dev);
|
|
|
|
if (retval < 0)
|
|
; /* Conditions are wrong. */
|
|
|
|
/* Synchronous suspends are not allowed in the RPM_RESUMING state. */
|
|
else if (dev->power.runtime_status == RPM_RESUMING &&
|
|
!(rpmflags & RPM_ASYNC))
|
|
retval = -EAGAIN;
|
|
if (retval)
|
|
goto out;
|
|
|
|
/* If the autosuspend_delay time hasn't expired yet, reschedule. */
|
|
if ((rpmflags & RPM_AUTO)
|
|
&& dev->power.runtime_status != RPM_SUSPENDING) {
|
|
unsigned long expires = pm_runtime_autosuspend_expiration(dev);
|
|
|
|
if (expires != 0) {
|
|
/* Pending requests need to be canceled. */
|
|
dev->power.request = RPM_REQ_NONE;
|
|
|
|
/*
|
|
* Optimization: If the timer is already running and is
|
|
* set to expire at or before the autosuspend delay,
|
|
* avoid the overhead of resetting it. Just let it
|
|
* expire; pm_suspend_timer_fn() will take care of the
|
|
* rest.
|
|
*/
|
|
if (!(dev->power.timer_expires && time_before_eq(
|
|
dev->power.timer_expires, expires))) {
|
|
dev->power.timer_expires = expires;
|
|
mod_timer(&dev->power.suspend_timer, expires);
|
|
}
|
|
dev->power.timer_autosuspends = 1;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Other scheduled or pending requests need to be canceled. */
|
|
pm_runtime_cancel_pending(dev);
|
|
|
|
if (dev->power.runtime_status == RPM_SUSPENDING) {
|
|
DEFINE_WAIT(wait);
|
|
|
|
if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
|
|
retval = -EINPROGRESS;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->power.irq_safe) {
|
|
spin_unlock(&dev->power.lock);
|
|
|
|
cpu_relax();
|
|
|
|
spin_lock(&dev->power.lock);
|
|
goto repeat;
|
|
}
|
|
|
|
/* Wait for the other suspend running in parallel with us. */
|
|
for (;;) {
|
|
prepare_to_wait(&dev->power.wait_queue, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
if (dev->power.runtime_status != RPM_SUSPENDING)
|
|
break;
|
|
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
}
|
|
finish_wait(&dev->power.wait_queue, &wait);
|
|
goto repeat;
|
|
}
|
|
|
|
if (dev->power.no_callbacks)
|
|
goto no_callback; /* Assume success. */
|
|
|
|
/* Carry out an asynchronous or a synchronous suspend. */
|
|
if (rpmflags & RPM_ASYNC) {
|
|
dev->power.request = (rpmflags & RPM_AUTO) ?
|
|
RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
|
|
if (!dev->power.request_pending) {
|
|
dev->power.request_pending = true;
|
|
queue_work(pm_wq, &dev->power.work);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
__update_runtime_status(dev, RPM_SUSPENDING);
|
|
|
|
callback = RPM_GET_CALLBACK(dev, runtime_suspend);
|
|
|
|
dev_pm_enable_wake_irq(dev);
|
|
retval = rpm_callback(callback, dev);
|
|
if (retval)
|
|
goto fail;
|
|
|
|
no_callback:
|
|
__update_runtime_status(dev, RPM_SUSPENDED);
|
|
pm_runtime_deactivate_timer(dev);
|
|
|
|
if (dev->parent) {
|
|
parent = dev->parent;
|
|
atomic_add_unless(&parent->power.child_count, -1, 0);
|
|
}
|
|
wake_up_all(&dev->power.wait_queue);
|
|
|
|
if (dev->power.deferred_resume) {
|
|
dev->power.deferred_resume = false;
|
|
rpm_resume(dev, 0);
|
|
retval = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
/* Maybe the parent is now able to suspend. */
|
|
if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
|
|
spin_unlock(&dev->power.lock);
|
|
|
|
spin_lock(&parent->power.lock);
|
|
rpm_idle(parent, RPM_ASYNC);
|
|
spin_unlock(&parent->power.lock);
|
|
|
|
spin_lock(&dev->power.lock);
|
|
}
|
|
|
|
out:
|
|
trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
|
|
|
|
return retval;
|
|
|
|
fail:
|
|
dev_pm_disable_wake_irq(dev);
|
|
__update_runtime_status(dev, RPM_ACTIVE);
|
|
dev->power.deferred_resume = false;
|
|
wake_up_all(&dev->power.wait_queue);
|
|
|
|
if (retval == -EAGAIN || retval == -EBUSY) {
|
|
dev->power.runtime_error = 0;
|
|
|
|
/*
|
|
* If the callback routine failed an autosuspend, and
|
|
* if the last_busy time has been updated so that there
|
|
* is a new autosuspend expiration time, automatically
|
|
* reschedule another autosuspend.
|
|
*/
|
|
if ((rpmflags & RPM_AUTO) &&
|
|
pm_runtime_autosuspend_expiration(dev) != 0)
|
|
goto repeat;
|
|
} else {
|
|
pm_runtime_cancel_pending(dev);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
/**
|
|
* rpm_resume - Carry out runtime resume of given device.
|
|
* @dev: Device to resume.
|
|
* @rpmflags: Flag bits.
|
|
*
|
|
* Check if the device's runtime PM status allows it to be resumed. Cancel
|
|
* any scheduled or pending requests. If another resume has been started
|
|
* earlier, either return immediately or wait for it to finish, depending on the
|
|
* RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
|
|
* parallel with this function, either tell the other process to resume after
|
|
* suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
|
|
* flag is set then queue a resume request; otherwise run the
|
|
* ->runtime_resume() callback directly. Queue an idle notification for the
|
|
* device if the resume succeeded.
|
|
*
|
|
* This function must be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static int rpm_resume(struct device *dev, int rpmflags)
|
|
__releases(&dev->power.lock) __acquires(&dev->power.lock)
|
|
{
|
|
int (*callback)(struct device *);
|
|
struct device *parent = NULL;
|
|
int retval = 0;
|
|
|
|
trace_rpm_resume_rcuidle(dev, rpmflags);
|
|
|
|
repeat:
|
|
if (dev->power.runtime_error)
|
|
retval = -EINVAL;
|
|
else if (dev->power.disable_depth == 1 && dev->power.is_suspended
|
|
&& dev->power.runtime_status == RPM_ACTIVE)
|
|
retval = 1;
|
|
else if (dev->power.disable_depth > 0)
|
|
retval = -EACCES;
|
|
if (retval)
|
|
goto out;
|
|
|
|
/*
|
|
* Other scheduled or pending requests need to be canceled. Small
|
|
* optimization: If an autosuspend timer is running, leave it running
|
|
* rather than cancelling it now only to restart it again in the near
|
|
* future.
|
|
*/
|
|
dev->power.request = RPM_REQ_NONE;
|
|
if (!dev->power.timer_autosuspends)
|
|
pm_runtime_deactivate_timer(dev);
|
|
|
|
if (dev->power.runtime_status == RPM_ACTIVE) {
|
|
retval = 1;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->power.runtime_status == RPM_RESUMING
|
|
|| dev->power.runtime_status == RPM_SUSPENDING) {
|
|
DEFINE_WAIT(wait);
|
|
|
|
if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
|
|
if (dev->power.runtime_status == RPM_SUSPENDING)
|
|
dev->power.deferred_resume = true;
|
|
else
|
|
retval = -EINPROGRESS;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->power.irq_safe) {
|
|
spin_unlock(&dev->power.lock);
|
|
|
|
cpu_relax();
|
|
|
|
spin_lock(&dev->power.lock);
|
|
goto repeat;
|
|
}
|
|
|
|
/* Wait for the operation carried out in parallel with us. */
|
|
for (;;) {
|
|
prepare_to_wait(&dev->power.wait_queue, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
if (dev->power.runtime_status != RPM_RESUMING
|
|
&& dev->power.runtime_status != RPM_SUSPENDING)
|
|
break;
|
|
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
}
|
|
finish_wait(&dev->power.wait_queue, &wait);
|
|
goto repeat;
|
|
}
|
|
|
|
/*
|
|
* See if we can skip waking up the parent. This is safe only if
|
|
* power.no_callbacks is set, because otherwise we don't know whether
|
|
* the resume will actually succeed.
|
|
*/
|
|
if (dev->power.no_callbacks && !parent && dev->parent) {
|
|
spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
|
|
if (dev->parent->power.disable_depth > 0
|
|
|| dev->parent->power.ignore_children
|
|
|| dev->parent->power.runtime_status == RPM_ACTIVE) {
|
|
atomic_inc(&dev->parent->power.child_count);
|
|
spin_unlock(&dev->parent->power.lock);
|
|
retval = 1;
|
|
goto no_callback; /* Assume success. */
|
|
}
|
|
spin_unlock(&dev->parent->power.lock);
|
|
}
|
|
|
|
/* Carry out an asynchronous or a synchronous resume. */
|
|
if (rpmflags & RPM_ASYNC) {
|
|
dev->power.request = RPM_REQ_RESUME;
|
|
if (!dev->power.request_pending) {
|
|
dev->power.request_pending = true;
|
|
queue_work(pm_wq, &dev->power.work);
|
|
}
|
|
retval = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (!parent && dev->parent) {
|
|
/*
|
|
* Increment the parent's usage counter and resume it if
|
|
* necessary. Not needed if dev is irq-safe; then the
|
|
* parent is permanently resumed.
|
|
*/
|
|
parent = dev->parent;
|
|
if (dev->power.irq_safe)
|
|
goto skip_parent;
|
|
spin_unlock(&dev->power.lock);
|
|
|
|
pm_runtime_get_noresume(parent);
|
|
|
|
spin_lock(&parent->power.lock);
|
|
/*
|
|
* We can resume if the parent's runtime PM is disabled or it
|
|
* is set to ignore children.
|
|
*/
|
|
if (!parent->power.disable_depth
|
|
&& !parent->power.ignore_children) {
|
|
rpm_resume(parent, 0);
|
|
if (parent->power.runtime_status != RPM_ACTIVE)
|
|
retval = -EBUSY;
|
|
}
|
|
spin_unlock(&parent->power.lock);
|
|
|
|
spin_lock(&dev->power.lock);
|
|
if (retval)
|
|
goto out;
|
|
goto repeat;
|
|
}
|
|
skip_parent:
|
|
|
|
if (dev->power.no_callbacks)
|
|
goto no_callback; /* Assume success. */
|
|
|
|
__update_runtime_status(dev, RPM_RESUMING);
|
|
|
|
callback = RPM_GET_CALLBACK(dev, runtime_resume);
|
|
|
|
dev_pm_disable_wake_irq(dev);
|
|
retval = rpm_callback(callback, dev);
|
|
if (retval) {
|
|
__update_runtime_status(dev, RPM_SUSPENDED);
|
|
pm_runtime_cancel_pending(dev);
|
|
dev_pm_enable_wake_irq(dev);
|
|
} else {
|
|
no_callback:
|
|
__update_runtime_status(dev, RPM_ACTIVE);
|
|
pm_runtime_mark_last_busy(dev);
|
|
if (parent)
|
|
atomic_inc(&parent->power.child_count);
|
|
}
|
|
wake_up_all(&dev->power.wait_queue);
|
|
|
|
if (retval >= 0)
|
|
rpm_idle(dev, RPM_ASYNC);
|
|
|
|
out:
|
|
if (parent && !dev->power.irq_safe) {
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
pm_runtime_put(parent);
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
}
|
|
|
|
trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_work - Universal runtime PM work function.
|
|
* @work: Work structure used for scheduling the execution of this function.
|
|
*
|
|
* Use @work to get the device object the work is to be done for, determine what
|
|
* is to be done and execute the appropriate runtime PM function.
|
|
*/
|
|
static void pm_runtime_work(struct work_struct *work)
|
|
{
|
|
struct device *dev = container_of(work, struct device, power.work);
|
|
enum rpm_request req;
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (!dev->power.request_pending)
|
|
goto out;
|
|
|
|
req = dev->power.request;
|
|
dev->power.request = RPM_REQ_NONE;
|
|
dev->power.request_pending = false;
|
|
|
|
switch (req) {
|
|
case RPM_REQ_NONE:
|
|
break;
|
|
case RPM_REQ_IDLE:
|
|
rpm_idle(dev, RPM_NOWAIT);
|
|
break;
|
|
case RPM_REQ_SUSPEND:
|
|
rpm_suspend(dev, RPM_NOWAIT);
|
|
break;
|
|
case RPM_REQ_AUTOSUSPEND:
|
|
rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
|
|
break;
|
|
case RPM_REQ_RESUME:
|
|
rpm_resume(dev, RPM_NOWAIT);
|
|
break;
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
|
|
/**
|
|
* pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
|
|
* @data: Device pointer passed by pm_schedule_suspend().
|
|
*
|
|
* Check if the time is right and queue a suspend request.
|
|
*/
|
|
static void pm_suspend_timer_fn(unsigned long data)
|
|
{
|
|
struct device *dev = (struct device *)data;
|
|
unsigned long flags;
|
|
unsigned long expires;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
expires = dev->power.timer_expires;
|
|
/* If 'expire' is after 'jiffies' we've been called too early. */
|
|
if (expires > 0 && !time_after(expires, jiffies)) {
|
|
dev->power.timer_expires = 0;
|
|
rpm_suspend(dev, dev->power.timer_autosuspends ?
|
|
(RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
}
|
|
|
|
/**
|
|
* pm_schedule_suspend - Set up a timer to submit a suspend request in future.
|
|
* @dev: Device to suspend.
|
|
* @delay: Time to wait before submitting a suspend request, in milliseconds.
|
|
*/
|
|
int pm_schedule_suspend(struct device *dev, unsigned int delay)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (!delay) {
|
|
retval = rpm_suspend(dev, RPM_ASYNC);
|
|
goto out;
|
|
}
|
|
|
|
retval = rpm_check_suspend_allowed(dev);
|
|
if (retval)
|
|
goto out;
|
|
|
|
/* Other scheduled or pending requests need to be canceled. */
|
|
pm_runtime_cancel_pending(dev);
|
|
|
|
dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
|
|
dev->power.timer_expires += !dev->power.timer_expires;
|
|
dev->power.timer_autosuspends = 0;
|
|
mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_schedule_suspend);
|
|
|
|
/**
|
|
* __pm_runtime_idle - Entry point for runtime idle operations.
|
|
* @dev: Device to send idle notification for.
|
|
* @rpmflags: Flag bits.
|
|
*
|
|
* If the RPM_GET_PUT flag is set, decrement the device's usage count and
|
|
* return immediately if it is larger than zero. Then carry out an idle
|
|
* notification, either synchronous or asynchronous.
|
|
*
|
|
* This routine may be called in atomic context if the RPM_ASYNC flag is set,
|
|
* or if pm_runtime_irq_safe() has been called.
|
|
*/
|
|
int __pm_runtime_idle(struct device *dev, int rpmflags)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
|
|
|
|
if (rpmflags & RPM_GET_PUT) {
|
|
if (!atomic_dec_and_test(&dev->power.usage_count))
|
|
return 0;
|
|
}
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
retval = rpm_idle(dev, rpmflags);
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_idle);
|
|
|
|
/**
|
|
* __pm_runtime_suspend - Entry point for runtime put/suspend operations.
|
|
* @dev: Device to suspend.
|
|
* @rpmflags: Flag bits.
|
|
*
|
|
* If the RPM_GET_PUT flag is set, decrement the device's usage count and
|
|
* return immediately if it is larger than zero. Then carry out a suspend,
|
|
* either synchronous or asynchronous.
|
|
*
|
|
* This routine may be called in atomic context if the RPM_ASYNC flag is set,
|
|
* or if pm_runtime_irq_safe() has been called.
|
|
*/
|
|
int __pm_runtime_suspend(struct device *dev, int rpmflags)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
|
|
|
|
if (rpmflags & RPM_GET_PUT) {
|
|
if (!atomic_dec_and_test(&dev->power.usage_count))
|
|
return 0;
|
|
}
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
retval = rpm_suspend(dev, rpmflags);
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
|
|
|
|
/**
|
|
* __pm_runtime_resume - Entry point for runtime resume operations.
|
|
* @dev: Device to resume.
|
|
* @rpmflags: Flag bits.
|
|
*
|
|
* If the RPM_GET_PUT flag is set, increment the device's usage count. Then
|
|
* carry out a resume, either synchronous or asynchronous.
|
|
*
|
|
* This routine may be called in atomic context if the RPM_ASYNC flag is set,
|
|
* or if pm_runtime_irq_safe() has been called.
|
|
*/
|
|
int __pm_runtime_resume(struct device *dev, int rpmflags)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
|
|
|
|
if (rpmflags & RPM_GET_PUT)
|
|
atomic_inc(&dev->power.usage_count);
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
retval = rpm_resume(dev, rpmflags);
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_resume);
|
|
|
|
/**
|
|
* pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Return -EINVAL if runtime PM is disabled for the device.
|
|
*
|
|
* If that's not the case and if the device's runtime PM status is RPM_ACTIVE
|
|
* and the runtime PM usage counter is nonzero, increment the counter and
|
|
* return 1. Otherwise return 0 without changing the counter.
|
|
*/
|
|
int pm_runtime_get_if_in_use(struct device *dev)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
retval = dev->power.disable_depth > 0 ? -EINVAL :
|
|
dev->power.runtime_status == RPM_ACTIVE
|
|
&& atomic_inc_not_zero(&dev->power.usage_count);
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
|
|
|
|
/**
|
|
* __pm_runtime_set_status - Set runtime PM status of a device.
|
|
* @dev: Device to handle.
|
|
* @status: New runtime PM status of the device.
|
|
*
|
|
* If runtime PM of the device is disabled or its power.runtime_error field is
|
|
* different from zero, the status may be changed either to RPM_ACTIVE, or to
|
|
* RPM_SUSPENDED, as long as that reflects the actual state of the device.
|
|
* However, if the device has a parent and the parent is not active, and the
|
|
* parent's power.ignore_children flag is unset, the device's status cannot be
|
|
* set to RPM_ACTIVE, so -EBUSY is returned in that case.
|
|
*
|
|
* If successful, __pm_runtime_set_status() clears the power.runtime_error field
|
|
* and the device parent's counter of unsuspended children is modified to
|
|
* reflect the new status. If the new status is RPM_SUSPENDED, an idle
|
|
* notification request for the parent is submitted.
|
|
*/
|
|
int __pm_runtime_set_status(struct device *dev, unsigned int status)
|
|
{
|
|
struct device *parent = dev->parent;
|
|
unsigned long flags;
|
|
bool notify_parent = false;
|
|
int error = 0;
|
|
|
|
if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (!dev->power.runtime_error && !dev->power.disable_depth) {
|
|
error = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->power.runtime_status == status)
|
|
goto out_set;
|
|
|
|
if (status == RPM_SUSPENDED) {
|
|
/* It always is possible to set the status to 'suspended'. */
|
|
if (parent) {
|
|
atomic_add_unless(&parent->power.child_count, -1, 0);
|
|
notify_parent = !parent->power.ignore_children;
|
|
}
|
|
goto out_set;
|
|
}
|
|
|
|
if (parent) {
|
|
spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
|
|
|
|
/*
|
|
* It is invalid to put an active child under a parent that is
|
|
* not active, has runtime PM enabled and the
|
|
* 'power.ignore_children' flag unset.
|
|
*/
|
|
if (!parent->power.disable_depth
|
|
&& !parent->power.ignore_children
|
|
&& parent->power.runtime_status != RPM_ACTIVE) {
|
|
dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
|
|
dev_name(dev),
|
|
dev_name(parent));
|
|
error = -EBUSY;
|
|
} else if (dev->power.runtime_status == RPM_SUSPENDED) {
|
|
atomic_inc(&parent->power.child_count);
|
|
}
|
|
|
|
spin_unlock(&parent->power.lock);
|
|
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
out_set:
|
|
__update_runtime_status(dev, status);
|
|
dev->power.runtime_error = 0;
|
|
out:
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
if (notify_parent)
|
|
pm_request_idle(parent);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
|
|
|
|
/**
|
|
* __pm_runtime_barrier - Cancel pending requests and wait for completions.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Flush all pending requests for the device from pm_wq and wait for all
|
|
* runtime PM operations involving the device in progress to complete.
|
|
*
|
|
* Should be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static void __pm_runtime_barrier(struct device *dev)
|
|
{
|
|
pm_runtime_deactivate_timer(dev);
|
|
|
|
if (dev->power.request_pending) {
|
|
dev->power.request = RPM_REQ_NONE;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
cancel_work_sync(&dev->power.work);
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
dev->power.request_pending = false;
|
|
}
|
|
|
|
if (dev->power.runtime_status == RPM_SUSPENDING
|
|
|| dev->power.runtime_status == RPM_RESUMING
|
|
|| dev->power.idle_notification) {
|
|
DEFINE_WAIT(wait);
|
|
|
|
/* Suspend, wake-up or idle notification in progress. */
|
|
for (;;) {
|
|
prepare_to_wait(&dev->power.wait_queue, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
if (dev->power.runtime_status != RPM_SUSPENDING
|
|
&& dev->power.runtime_status != RPM_RESUMING
|
|
&& !dev->power.idle_notification)
|
|
break;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
}
|
|
finish_wait(&dev->power.wait_queue, &wait);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_barrier - Flush pending requests and wait for completions.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Prevent the device from being suspended by incrementing its usage counter and
|
|
* if there's a pending resume request for the device, wake the device up.
|
|
* Next, make sure that all pending requests for the device have been flushed
|
|
* from pm_wq and wait for all runtime PM operations involving the device in
|
|
* progress to complete.
|
|
*
|
|
* Return value:
|
|
* 1, if there was a resume request pending and the device had to be woken up,
|
|
* 0, otherwise
|
|
*/
|
|
int pm_runtime_barrier(struct device *dev)
|
|
{
|
|
int retval = 0;
|
|
|
|
pm_runtime_get_noresume(dev);
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (dev->power.request_pending
|
|
&& dev->power.request == RPM_REQ_RESUME) {
|
|
rpm_resume(dev, 0);
|
|
retval = 1;
|
|
}
|
|
|
|
__pm_runtime_barrier(dev);
|
|
|
|
spin_unlock_irq(&dev->power.lock);
|
|
pm_runtime_put_noidle(dev);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_barrier);
|
|
|
|
/**
|
|
* __pm_runtime_disable - Disable runtime PM of a device.
|
|
* @dev: Device to handle.
|
|
* @check_resume: If set, check if there's a resume request for the device.
|
|
*
|
|
* Increment power.disable_depth for the device and if it was zero previously,
|
|
* cancel all pending runtime PM requests for the device and wait for all
|
|
* operations in progress to complete. The device can be either active or
|
|
* suspended after its runtime PM has been disabled.
|
|
*
|
|
* If @check_resume is set and there's a resume request pending when
|
|
* __pm_runtime_disable() is called and power.disable_depth is zero, the
|
|
* function will wake up the device before disabling its runtime PM.
|
|
*/
|
|
void __pm_runtime_disable(struct device *dev, bool check_resume)
|
|
{
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (dev->power.disable_depth > 0) {
|
|
dev->power.disable_depth++;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Wake up the device if there's a resume request pending, because that
|
|
* means there probably is some I/O to process and disabling runtime PM
|
|
* shouldn't prevent the device from processing the I/O.
|
|
*/
|
|
if (check_resume && dev->power.request_pending
|
|
&& dev->power.request == RPM_REQ_RESUME) {
|
|
/*
|
|
* Prevent suspends and idle notifications from being carried
|
|
* out after we have woken up the device.
|
|
*/
|
|
pm_runtime_get_noresume(dev);
|
|
|
|
rpm_resume(dev, 0);
|
|
|
|
pm_runtime_put_noidle(dev);
|
|
}
|
|
|
|
if (!dev->power.disable_depth++)
|
|
__pm_runtime_barrier(dev);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_disable);
|
|
|
|
/**
|
|
* pm_runtime_enable - Enable runtime PM of a device.
|
|
* @dev: Device to handle.
|
|
*/
|
|
void pm_runtime_enable(struct device *dev)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (dev->power.disable_depth > 0)
|
|
dev->power.disable_depth--;
|
|
else
|
|
dev_warn(dev, "Unbalanced %s!\n", __func__);
|
|
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_enable);
|
|
|
|
/**
|
|
* pm_runtime_forbid - Block runtime PM of a device.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Increase the device's usage count and clear its power.runtime_auto flag,
|
|
* so that it cannot be suspended at run time until pm_runtime_allow() is called
|
|
* for it.
|
|
*/
|
|
void pm_runtime_forbid(struct device *dev)
|
|
{
|
|
spin_lock_irq(&dev->power.lock);
|
|
if (!dev->power.runtime_auto)
|
|
goto out;
|
|
|
|
dev->power.runtime_auto = false;
|
|
atomic_inc(&dev->power.usage_count);
|
|
rpm_resume(dev, 0);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_forbid);
|
|
|
|
/**
|
|
* pm_runtime_allow - Unblock runtime PM of a device.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Decrease the device's usage count and set its power.runtime_auto flag.
|
|
*/
|
|
void pm_runtime_allow(struct device *dev)
|
|
{
|
|
spin_lock_irq(&dev->power.lock);
|
|
if (dev->power.runtime_auto)
|
|
goto out;
|
|
|
|
dev->power.runtime_auto = true;
|
|
if (atomic_dec_and_test(&dev->power.usage_count))
|
|
rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_allow);
|
|
|
|
/**
|
|
* pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
|
|
* @dev: Device to handle.
|
|
*
|
|
* Set the power.no_callbacks flag, which tells the PM core that this
|
|
* device is power-managed through its parent and has no runtime PM
|
|
* callbacks of its own. The runtime sysfs attributes will be removed.
|
|
*/
|
|
void pm_runtime_no_callbacks(struct device *dev)
|
|
{
|
|
spin_lock_irq(&dev->power.lock);
|
|
dev->power.no_callbacks = 1;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
if (device_is_registered(dev))
|
|
rpm_sysfs_remove(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
|
|
|
|
/**
|
|
* pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
|
|
* @dev: Device to handle
|
|
*
|
|
* Set the power.irq_safe flag, which tells the PM core that the
|
|
* ->runtime_suspend() and ->runtime_resume() callbacks for this device should
|
|
* always be invoked with the spinlock held and interrupts disabled. It also
|
|
* causes the parent's usage counter to be permanently incremented, preventing
|
|
* the parent from runtime suspending -- otherwise an irq-safe child might have
|
|
* to wait for a non-irq-safe parent.
|
|
*/
|
|
void pm_runtime_irq_safe(struct device *dev)
|
|
{
|
|
if (dev->parent)
|
|
pm_runtime_get_sync(dev->parent);
|
|
spin_lock_irq(&dev->power.lock);
|
|
dev->power.irq_safe = 1;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
|
|
|
|
/**
|
|
* update_autosuspend - Handle a change to a device's autosuspend settings.
|
|
* @dev: Device to handle.
|
|
* @old_delay: The former autosuspend_delay value.
|
|
* @old_use: The former use_autosuspend value.
|
|
*
|
|
* Prevent runtime suspend if the new delay is negative and use_autosuspend is
|
|
* set; otherwise allow it. Send an idle notification if suspends are allowed.
|
|
*
|
|
* This function must be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static void update_autosuspend(struct device *dev, int old_delay, int old_use)
|
|
{
|
|
int delay = dev->power.autosuspend_delay;
|
|
|
|
/* Should runtime suspend be prevented now? */
|
|
if (dev->power.use_autosuspend && delay < 0) {
|
|
|
|
/* If it used to be allowed then prevent it. */
|
|
if (!old_use || old_delay >= 0) {
|
|
atomic_inc(&dev->power.usage_count);
|
|
rpm_resume(dev, 0);
|
|
}
|
|
}
|
|
|
|
/* Runtime suspend should be allowed now. */
|
|
else {
|
|
|
|
/* If it used to be prevented then allow it. */
|
|
if (old_use && old_delay < 0)
|
|
atomic_dec(&dev->power.usage_count);
|
|
|
|
/* Maybe we can autosuspend now. */
|
|
rpm_idle(dev, RPM_AUTO);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
|
|
* @dev: Device to handle.
|
|
* @delay: Value of the new delay in milliseconds.
|
|
*
|
|
* Set the device's power.autosuspend_delay value. If it changes to negative
|
|
* and the power.use_autosuspend flag is set, prevent runtime suspends. If it
|
|
* changes the other way, allow runtime suspends.
|
|
*/
|
|
void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
|
|
{
|
|
int old_delay, old_use;
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
old_delay = dev->power.autosuspend_delay;
|
|
old_use = dev->power.use_autosuspend;
|
|
dev->power.autosuspend_delay = delay;
|
|
update_autosuspend(dev, old_delay, old_use);
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
|
|
|
|
/**
|
|
* __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
|
|
* @dev: Device to handle.
|
|
* @use: New value for use_autosuspend.
|
|
*
|
|
* Set the device's power.use_autosuspend flag, and allow or prevent runtime
|
|
* suspends as needed.
|
|
*/
|
|
void __pm_runtime_use_autosuspend(struct device *dev, bool use)
|
|
{
|
|
int old_delay, old_use;
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
old_delay = dev->power.autosuspend_delay;
|
|
old_use = dev->power.use_autosuspend;
|
|
dev->power.use_autosuspend = use;
|
|
update_autosuspend(dev, old_delay, old_use);
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
|
|
|
|
/**
|
|
* pm_runtime_init - Initialize runtime PM fields in given device object.
|
|
* @dev: Device object to initialize.
|
|
*/
|
|
void pm_runtime_init(struct device *dev)
|
|
{
|
|
dev->power.runtime_status = RPM_SUSPENDED;
|
|
dev->power.idle_notification = false;
|
|
|
|
dev->power.disable_depth = 1;
|
|
atomic_set(&dev->power.usage_count, 0);
|
|
|
|
dev->power.runtime_error = 0;
|
|
|
|
atomic_set(&dev->power.child_count, 0);
|
|
pm_suspend_ignore_children(dev, false);
|
|
dev->power.runtime_auto = true;
|
|
|
|
dev->power.request_pending = false;
|
|
dev->power.request = RPM_REQ_NONE;
|
|
dev->power.deferred_resume = false;
|
|
dev->power.accounting_timestamp = jiffies;
|
|
INIT_WORK(&dev->power.work, pm_runtime_work);
|
|
|
|
dev->power.timer_expires = 0;
|
|
setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
|
|
(unsigned long)dev);
|
|
|
|
init_waitqueue_head(&dev->power.wait_queue);
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
|
|
* @dev: Device object to re-initialize.
|
|
*/
|
|
void pm_runtime_reinit(struct device *dev)
|
|
{
|
|
if (!pm_runtime_enabled(dev)) {
|
|
if (dev->power.runtime_status == RPM_ACTIVE)
|
|
pm_runtime_set_suspended(dev);
|
|
if (dev->power.irq_safe) {
|
|
spin_lock_irq(&dev->power.lock);
|
|
dev->power.irq_safe = 0;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
if (dev->parent)
|
|
pm_runtime_put(dev->parent);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_remove - Prepare for removing a device from device hierarchy.
|
|
* @dev: Device object being removed from device hierarchy.
|
|
*/
|
|
void pm_runtime_remove(struct device *dev)
|
|
{
|
|
__pm_runtime_disable(dev, false);
|
|
pm_runtime_reinit(dev);
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_force_suspend - Force a device into suspend state if needed.
|
|
* @dev: Device to suspend.
|
|
*
|
|
* Disable runtime PM so we safely can check the device's runtime PM status and
|
|
* if it is active, invoke it's .runtime_suspend callback to bring it into
|
|
* suspend state. Keep runtime PM disabled to preserve the state unless we
|
|
* encounter errors.
|
|
*
|
|
* Typically this function may be invoked from a system suspend callback to make
|
|
* sure the device is put into low power state.
|
|
*/
|
|
int pm_runtime_force_suspend(struct device *dev)
|
|
{
|
|
int (*callback)(struct device *);
|
|
int ret = 0;
|
|
|
|
pm_runtime_disable(dev);
|
|
if (pm_runtime_status_suspended(dev))
|
|
return 0;
|
|
|
|
callback = RPM_GET_CALLBACK(dev, runtime_suspend);
|
|
|
|
if (!callback) {
|
|
ret = -ENOSYS;
|
|
goto err;
|
|
}
|
|
|
|
ret = callback(dev);
|
|
if (ret)
|
|
goto err;
|
|
|
|
pm_runtime_set_suspended(dev);
|
|
return 0;
|
|
err:
|
|
pm_runtime_enable(dev);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
|
|
|
|
/**
|
|
* pm_runtime_force_resume - Force a device into resume state.
|
|
* @dev: Device to resume.
|
|
*
|
|
* Prior invoking this function we expect the user to have brought the device
|
|
* into low power state by a call to pm_runtime_force_suspend(). Here we reverse
|
|
* those actions and brings the device into full power. We update the runtime PM
|
|
* status and re-enables runtime PM.
|
|
*
|
|
* Typically this function may be invoked from a system resume callback to make
|
|
* sure the device is put into full power state.
|
|
*/
|
|
int pm_runtime_force_resume(struct device *dev)
|
|
{
|
|
int (*callback)(struct device *);
|
|
int ret = 0;
|
|
|
|
callback = RPM_GET_CALLBACK(dev, runtime_resume);
|
|
|
|
if (!callback) {
|
|
ret = -ENOSYS;
|
|
goto out;
|
|
}
|
|
|
|
if (!pm_runtime_status_suspended(dev))
|
|
goto out;
|
|
|
|
ret = pm_runtime_set_active(dev);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = callback(dev);
|
|
if (ret) {
|
|
pm_runtime_set_suspended(dev);
|
|
goto out;
|
|
}
|
|
|
|
pm_runtime_mark_last_busy(dev);
|
|
out:
|
|
pm_runtime_enable(dev);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_force_resume);
|