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![Venkatesh Pallipadi](/assets/img/avatar_default.png)
cpuidle and acpi driver interaction bug with the way cpuidle_register_driver() is called. Due to this bug, there will be oops on AC<->DC on some systems, where they support C-states in one DC and not in AC. The current code does ON BOOT: Look at CST and other C-state info to see whether more than C1 is supported. If it is, then acpi processor_idle does a cpuidle_register_driver() call, which internally enables the device. ON CST change notification (AC<->DC) and on suspend-resume: acpi driver temporarily disables device, updates the device with any new C-states, and reenables the device. The problem is is on boot, there are no C2, C3 states supported and we skip the register. Later on AC<->DC, we may get a CST notification and we try to reevaluate CST and enabled the device, without actually registering it. This causes breakage as we try to create /sys fs sub directory, without the parent directory which is created at register time. Thanks to Sanjeev for reporting the problem here. http://bugzilla.kernel.org/show_bug.cgi?id=10394 Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
191 lines
5 KiB
C
191 lines
5 KiB
C
/*
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* cpuidle.h - a generic framework for CPU idle power management
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*
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* (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* Shaohua Li <shaohua.li@intel.com>
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* Adam Belay <abelay@novell.com>
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*
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* This code is licenced under the GPL.
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*/
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#ifndef _LINUX_CPUIDLE_H
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#define _LINUX_CPUIDLE_H
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#include <linux/percpu.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/kobject.h>
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#include <linux/completion.h>
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#define CPUIDLE_STATE_MAX 8
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#define CPUIDLE_NAME_LEN 16
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#define CPUIDLE_DESC_LEN 32
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struct cpuidle_device;
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/****************************
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* CPUIDLE DEVICE INTERFACE *
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****************************/
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struct cpuidle_state {
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char name[CPUIDLE_NAME_LEN];
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char desc[CPUIDLE_DESC_LEN];
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void *driver_data;
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unsigned int flags;
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unsigned int exit_latency; /* in US */
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unsigned int power_usage; /* in mW */
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unsigned int target_residency; /* in US */
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unsigned long long usage;
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unsigned long long time; /* in US */
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int (*enter) (struct cpuidle_device *dev,
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struct cpuidle_state *state);
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};
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/* Idle State Flags */
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#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
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#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
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#define CPUIDLE_FLAG_POLL (0x10) /* no latency, no savings */
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#define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */
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#define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */
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#define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */
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#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
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/**
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* cpuidle_get_statedata - retrieves private driver state data
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* @state: the state
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*/
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static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
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{
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return state->driver_data;
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}
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/**
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* cpuidle_set_statedata - stores private driver state data
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* @state: the state
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* @data: the private data
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*/
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static inline void
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cpuidle_set_statedata(struct cpuidle_state *state, void *data)
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{
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state->driver_data = data;
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}
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struct cpuidle_state_kobj {
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struct cpuidle_state *state;
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struct completion kobj_unregister;
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struct kobject kobj;
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};
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struct cpuidle_device {
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unsigned int registered:1;
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unsigned int enabled:1;
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unsigned int cpu;
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int last_residency;
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int state_count;
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struct cpuidle_state states[CPUIDLE_STATE_MAX];
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struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
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struct cpuidle_state *last_state;
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struct list_head device_list;
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struct kobject kobj;
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struct completion kobj_unregister;
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void *governor_data;
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struct cpuidle_state *safe_state;
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};
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DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
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/**
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* cpuidle_get_last_residency - retrieves the last state's residency time
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* @dev: the target CPU
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*
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* NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
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*/
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static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
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{
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return dev->last_residency;
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}
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/****************************
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* CPUIDLE DRIVER INTERFACE *
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****************************/
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struct cpuidle_driver {
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char name[CPUIDLE_NAME_LEN];
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struct module *owner;
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};
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#ifdef CONFIG_CPU_IDLE
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extern int cpuidle_register_driver(struct cpuidle_driver *drv);
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extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
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extern int cpuidle_register_device(struct cpuidle_device *dev);
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extern void cpuidle_unregister_device(struct cpuidle_device *dev);
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extern void cpuidle_pause_and_lock(void);
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extern void cpuidle_resume_and_unlock(void);
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extern int cpuidle_enable_device(struct cpuidle_device *dev);
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extern void cpuidle_disable_device(struct cpuidle_device *dev);
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#else
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static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
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{return 0;}
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static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
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static inline int cpuidle_register_device(struct cpuidle_device *dev)
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{return 0;}
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static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
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static inline void cpuidle_pause_and_lock(void) { }
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static inline void cpuidle_resume_and_unlock(void) { }
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static inline int cpuidle_enable_device(struct cpuidle_device *dev)
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{return 0;}
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static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
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#endif
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/******************************
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* CPUIDLE GOVERNOR INTERFACE *
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******************************/
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struct cpuidle_governor {
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char name[CPUIDLE_NAME_LEN];
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struct list_head governor_list;
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unsigned int rating;
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int (*enable) (struct cpuidle_device *dev);
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void (*disable) (struct cpuidle_device *dev);
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int (*select) (struct cpuidle_device *dev);
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void (*reflect) (struct cpuidle_device *dev);
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struct module *owner;
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};
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#ifdef CONFIG_CPU_IDLE
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extern int cpuidle_register_governor(struct cpuidle_governor *gov);
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extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
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#else
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static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
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{return 0;}
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static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
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#endif
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#ifdef CONFIG_ARCH_HAS_CPU_RELAX
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#define CPUIDLE_DRIVER_STATE_START 1
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#else
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#define CPUIDLE_DRIVER_STATE_START 0
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#endif
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#endif /* _LINUX_CPUIDLE_H */
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