diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/stop_machine.h | 69 |
1 files changed, 63 insertions, 6 deletions
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 0e552e72a4c4..6b524a0d02e4 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -6,8 +6,6 @@ #include <linux/list.h> #include <asm/system.h> -#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) - /* * stop_cpu[s]() is simplistic per-cpu maximum priority cpu * monopolization mechanism. The caller can specify a non-sleeping @@ -18,9 +16,10 @@ * 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; @@ -34,12 +33,70 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); +#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 (cpu == smp_processor_id()) { + 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 int stop_cpus(const struct cpumask *cpumask, + cpu_stop_fn_t fn, void *arg) +{ + if (cpumask_test_cpu(raw_smp_processor_id(), cpumask)) + return stop_one_cpu(raw_smp_processor_id(), fn, arg); + return -ENOENT; +} + +static inline int try_stop_cpus(const struct cpumask *cpumask, + cpu_stop_fn_t fn, void *arg) +{ + return stop_cpus(cpumask, fn, arg); +} + +#endif /* CONFIG_SMP */ + /* * stop_machine "Bogolock": stop the entire machine, disable * interrupts. This is a very heavy lock, which is equivalent to * grabbing every spinlock (and more). So the "read" side to such a * lock is anything which disables preeempt. */ +#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) /** * stop_machine: freeze the machine on all CPUs and run this function @@ -67,7 +124,7 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); */ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus); -#else +#else /* CONFIG_STOP_MACHINE && CONFIG_SMP */ static inline int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus) @@ -79,5 +136,5 @@ static inline int stop_machine(int (*fn)(void *), void *data, return ret; } -#endif /* CONFIG_SMP */ -#endif /* _LINUX_STOP_MACHINE */ +#endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */ +#endif /* _LINUX_STOP_MACHINE */ |