1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 27dfb7103SNigel Cunningham /* Freezer declarations */ 37dfb7103SNigel Cunningham 483144186SRafael J. Wysocki #ifndef FREEZER_H_INCLUDED 583144186SRafael J. Wysocki #define FREEZER_H_INCLUDED 683144186SRafael J. Wysocki 70f9548caSMandeep Singh Baines #include <linux/debug_locks.h> 85c543effSRandy Dunlap #include <linux/sched.h> 9e42837bcSRafael J. Wysocki #include <linux/wait.h> 10a3201227STejun Heo #include <linux/atomic.h> 11*f5d39b02SPeter Zijlstra #include <linux/jump_label.h> 125c543effSRandy Dunlap 138174f150SMatt Helsley #ifdef CONFIG_FREEZER 14*f5d39b02SPeter Zijlstra DECLARE_STATIC_KEY_FALSE(freezer_active); 15*f5d39b02SPeter Zijlstra 16a3201227STejun Heo extern bool pm_freezing; /* PM freezing in effect */ 17a3201227STejun Heo extern bool pm_nosig_freezing; /* PM nosig freezing in effect */ 18a3201227STejun Heo 197dfb7103SNigel Cunningham /* 20957d1282SLi Fei * Timeout for stopping processes 21957d1282SLi Fei */ 22957d1282SLi Fei extern unsigned int freeze_timeout_msecs; 23957d1282SLi Fei 24957d1282SLi Fei /* 257dfb7103SNigel Cunningham * Check if a process has been frozen 267dfb7103SNigel Cunningham */ 27*f5d39b02SPeter Zijlstra extern bool frozen(struct task_struct *p); 287dfb7103SNigel Cunningham 29a3201227STejun Heo extern bool freezing_slow_path(struct task_struct *p); 30a3201227STejun Heo 317dfb7103SNigel Cunningham /* 327dfb7103SNigel Cunningham * Check if there is a request to freeze a process 337dfb7103SNigel Cunningham */ freezing(struct task_struct * p)34a3201227STejun Heostatic inline bool freezing(struct task_struct *p) 357dfb7103SNigel Cunningham { 36*f5d39b02SPeter Zijlstra if (static_branch_unlikely(&freezer_active)) 37a3201227STejun Heo return freezing_slow_path(p); 38*f5d39b02SPeter Zijlstra 39*f5d39b02SPeter Zijlstra return false; 407dfb7103SNigel Cunningham } 417dfb7103SNigel Cunningham 42dc52ddc0SMatt Helsley /* Takes and releases task alloc lock using task_lock() */ 43a5be2d0dSTejun Heo extern void __thaw_task(struct task_struct *t); 447dfb7103SNigel Cunningham 458a32c441STejun Heo extern bool __refrigerator(bool check_kthr_stop); 467dfb7103SNigel Cunningham extern int freeze_processes(void); 472aede851SRafael J. Wysocki extern int freeze_kernel_threads(void); 48a9b6f562SRafael J. Wysocki extern void thaw_processes(void); 49181e9bdeSRafael J. Wysocki extern void thaw_kernel_threads(void); 507dfb7103SNigel Cunningham try_to_freeze(void)51*f5d39b02SPeter Zijlstrastatic inline bool try_to_freeze(void) 527dfb7103SNigel Cunningham { 53a0acae0eSTejun Heo might_sleep(); 54a0acae0eSTejun Heo if (likely(!freezing(current))) 55a0acae0eSTejun Heo return false; 560f9548caSMandeep Singh Baines if (!(current->flags & PF_NOFREEZE)) 570f9548caSMandeep Singh Baines debug_check_no_locks_held(); 58*f5d39b02SPeter Zijlstra return __refrigerator(false); 59416ad3c9SColin Cross } 60416ad3c9SColin Cross 61839e3407STejun Heo extern bool freeze_task(struct task_struct *p); 6234b087e4STejun Heo extern bool set_freezable(void); 638174f150SMatt Helsley 64dc52ddc0SMatt Helsley #ifdef CONFIG_CGROUP_FREEZER 6522b4e111STejun Heo extern bool cgroup_freezing(struct task_struct *task); 66dc52ddc0SMatt Helsley #else /* !CONFIG_CGROUP_FREEZER */ cgroup_freezing(struct task_struct * task)6722b4e111STejun Heostatic inline bool cgroup_freezing(struct task_struct *task) 685a7aadfeSMatt Helsley { 6922b4e111STejun Heo return false; 705a7aadfeSMatt Helsley } 71dc52ddc0SMatt Helsley #endif /* !CONFIG_CGROUP_FREEZER */ 72dc52ddc0SMatt Helsley 738174f150SMatt Helsley #else /* !CONFIG_FREEZER */ frozen(struct task_struct * p)74948246f7STejun Heostatic inline bool frozen(struct task_struct *p) { return false; } freezing(struct task_struct * p)75a3201227STejun Heostatic inline bool freezing(struct task_struct *p) { return false; } __thaw_task(struct task_struct * t)7662c9ea6bSStephen Rothwellstatic inline void __thaw_task(struct task_struct *t) {} 777dfb7103SNigel Cunningham __refrigerator(bool check_kthr_stop)788a32c441STejun Heostatic inline bool __refrigerator(bool check_kthr_stop) { return false; } freeze_processes(void)792aede851SRafael J. Wysockistatic inline int freeze_processes(void) { return -ENOSYS; } freeze_kernel_threads(void)802aede851SRafael J. Wysockistatic inline int freeze_kernel_threads(void) { return -ENOSYS; } thaw_processes(void)817dfb7103SNigel Cunninghamstatic inline void thaw_processes(void) {} thaw_kernel_threads(void)82181e9bdeSRafael J. Wysockistatic inline void thaw_kernel_threads(void) {} 837dfb7103SNigel Cunningham try_to_freeze(void)84a0acae0eSTejun Heostatic inline bool try_to_freeze(void) { return false; } 857dfb7103SNigel Cunningham set_freezable(void)8683144186SRafael J. Wysockistatic inline void set_freezable(void) {} 87e42837bcSRafael J. Wysocki 888174f150SMatt Helsley #endif /* !CONFIG_FREEZER */ 8983144186SRafael J. Wysocki 9083144186SRafael J. Wysocki #endif /* FREEZER_H_INCLUDED */ 91