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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_STOP_MACHINE#define _LINUX_STOP_MACHINE
#include <linux/bug.h>#include <linux/cpu.h>#include <linux/cpumask_types.h>#include <linux/smp.h>#include <linux/list.h>
/* * stop_cpu[s]() is simplistic per-cpu maximum priority cpu * monopolization mechanism. The caller can specify a non-sleeping * function to be executed on a single or multiple cpus preempting all * other processes and monopolizing those cpus until it finishes. * * Resources for this mechanism are preallocated when a cpu is brought * up and requests are guaranteed to be served as long as the target * cpus are online. */typedef int (*cpu_stop_fn_t)(void *arg);
#ifdef CONFIG_SMP
struct cpu_stop_work { struct list_head list; /* cpu_stopper->works */ cpu_stop_fn_t fn; unsigned long caller; void *arg; struct cpu_stop_done *done;};
int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg);int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg);void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf);void stop_machine_park(int cpu);void stop_machine_unpark(int cpu);void stop_machine_yield(const struct cpumask *cpumask);
extern void print_stop_info(const char *log_lvl, struct task_struct *task);
#else /* CONFIG_SMP */
#include <linux/workqueue.h>
struct cpu_stop_work { struct work_struct work; cpu_stop_fn_t fn; void *arg;};
static inline int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg){ int ret = -ENOENT; preempt_disable(); if (cpu == smp_processor_id()) ret = fn(arg); preempt_enable(); return ret;}
static void stop_one_cpu_nowait_workfn(struct work_struct *work){ struct cpu_stop_work *stwork = container_of(work, struct cpu_stop_work, work); preempt_disable(); stwork->fn(stwork->arg); preempt_enable();}
static inline void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf){ if (WARN_ON_ONCE(cpu != smp_processor_id())) return;
INIT_WORK(&work_buf->work, stop_one_cpu_nowait_workfn); work_buf->fn = fn; work_buf->arg = arg; schedule_work(&work_buf->work);}
static inline void print_stop_info(const char *log_lvl, struct task_struct *task) { }
#endif /* CONFIG_SMP */
/* * stop_machine "Bogolock": stop the entire machine, disable interrupts. * This is a very heavy lock, which is equivalent to grabbing every raw * spinlock (and more). So the "read" side to such a lock is anything * which disables preemption. */#if defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU)
/** * stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr to pass to @fn() * @cpus: the cpus to run @fn() on (NULL = one unspecified online CPU) * * Description: This causes a thread to be scheduled on every CPU, which * will run with interrupts disabled. Each CPU specified by @cpus will * run @fn. While @fn is executing, there will no other CPUs holding * a raw spinlock or running within any other type of preempt-disabled * region of code. * * When @cpus specifies only a single CPU, this can be thought of as * a reader-writer lock where readers disable preemption (for example, * by holding a raw spinlock) and where the insanely heavy writers run * @fn while also preventing any other CPU from doing any useful work. * These writers can also be thought of as having implicitly grabbed every * raw spinlock in the kernel. * * When @fn is a no-op, this can be thought of as an RCU implementation * where readers again disable preemption and writers use stop_machine() * in place of synchronize_rcu(), albeit with orders of magnitude more * disruption than even that of synchronize_rcu_expedited(). * * Although only one stop_machine() operation can proceed at a time, * the possibility of blocking in cpus_read_lock() means that the caller * cannot usefully rely on this serialization. * * Return: 0 if all invocations of @fn return zero. Otherwise, the * value returned by an arbitrarily chosen member of the set of calls to * @fn that returned non-zero. */int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
/** * stop_machine_cpuslocked: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr to pass to @fn() * @cpus: the cpus to run @fn() on (NULL = one unspecified online CPU) * * Same as above. Avoids nested calls to cpus_read_lock(). * * Context: Must be called from within a cpus_read_lock() protected region. */int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
/** * stop_core_cpuslocked: - stop all threads on just one core * @cpu: any cpu in the targeted core * @fn: the function to run on each CPU in the core containing @cpu * @data: the data ptr to pass to @fn() * * Same as above, but instead of every CPU, only the logical CPUs of the * single core containing @cpu are affected. * * Context: Must be called from within a cpus_read_lock() protected region. * * Return: 0 if all invocations of @fn return zero. Otherwise, the * value returned by an arbitrarily chosen member of the set of calls to * @fn that returned non-zero. */int stop_core_cpuslocked(unsigned int cpu, cpu_stop_fn_t fn, void *data);
int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);#else /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
static __always_inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus){ unsigned long flags; int ret; local_irq_save(flags); ret = fn(data); local_irq_restore(flags); return ret;}
static __always_inline intstop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus){ return stop_machine_cpuslocked(fn, data, cpus);}
static __always_inline intstop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus){ return stop_machine(fn, data, cpus);}
#endif /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */#endif /* _LINUX_STOP_MACHINE */