diff --git a/include/linux/sched.h b/include/linux/sched.h index 4b83cb230006..ed3bb19d1337 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -904,6 +904,8 @@ extern int task_curr(const task_t *p); extern int idle_cpu(int cpu); extern int sched_setscheduler(struct task_struct *, int, struct sched_param *); extern task_t *idle_task(int cpu); +extern task_t *curr_task(int cpu); +extern void set_curr_task(int cpu, task_t *p); void yield(void); diff --git a/kernel/sched.c b/kernel/sched.c index dbd4490afec1..e9ff04a9b56d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3576,6 +3576,32 @@ task_t *idle_task(int cpu) return cpu_rq(cpu)->idle; } +/** + * curr_task - return the current task for a given cpu. + * @cpu: the processor in question. + */ +task_t *curr_task(int cpu) +{ + return cpu_curr(cpu); +} + +/** + * set_curr_task - set the current task for a given cpu. + * @cpu: the processor in question. + * @p: the task pointer to set. + * + * Description: This function must only be used when non-maskable interrupts + * are serviced on a separate stack. It allows the architecture to switch the + * notion of the current task on a cpu in a non-blocking manner. This function + * must be called with interrupts disabled, the caller must save the original + * value of the current task (see curr_task() above) and restore that value + * before reenabling interrupts. + */ +void set_curr_task(int cpu, task_t *p) +{ + cpu_curr(cpu) = p; +} + /** * find_process_by_pid - find a process with a matching PID value. * @pid: the pid in question.