sched/headers: Move task lifetime APIs from <linux/sched.h> to <linux/sched/task.h>

There's a fair amount of task lifetime management (a.k.a fork()/exit())
related APIs in <linux/sched.h>, but only a small fraction of
the users of the generic sched.h header make use of them.

Move these functions to the <linux/sched/task.h> header.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 0023c91ff821..e93638a03515 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -1,6 +1,103 @@
 #ifndef _LINUX_SCHED_TASK_H
 #define _LINUX_SCHED_TASK_H
 
+/*
+ * Interface between the scheduler and various task lifetime (fork()/exit())
+ * functionality:
+ */
+
 #include <linux/sched.h>
 
+/*
+ * This serializes "schedule()" and also protects
+ * the run-queue from deletions/modifications (but
+ * _adding_ to the beginning of the run-queue has
+ * a separate lock).
+ */
+extern rwlock_t tasklist_lock;
+extern spinlock_t mmlist_lock;
+
+#ifdef CONFIG_PROVE_RCU
+extern int lockdep_tasklist_lock_is_held(void);
+#endif /* #ifdef CONFIG_PROVE_RCU */
+
+extern asmlinkage void schedule_tail(struct task_struct *prev);
+extern void init_idle(struct task_struct *idle, int cpu);
+extern void init_idle_bootup_task(struct task_struct *idle);
+
+static inline void rcu_copy_process(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RCU
+        p->rcu_read_lock_nesting = 0;
+        p->rcu_read_unlock_special.s = 0;
+        p->rcu_blocked_node = NULL;
+        INIT_LIST_HEAD(&p->rcu_node_entry);
+#endif /* #ifdef CONFIG_PREEMPT_RCU */
+#ifdef CONFIG_TASKS_RCU
+        p->rcu_tasks_holdout = false;
+        INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
+        p->rcu_tasks_idle_cpu = -1;
+#endif /* #ifdef CONFIG_TASKS_RCU */
+}
+
+extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
+extern void sched_dead(struct task_struct *p);
+
+void __noreturn do_task_dead(void);
+
+extern void proc_caches_init(void);
+
+extern void release_task(struct task_struct * p);
+
+#ifdef CONFIG_HAVE_COPY_THREAD_TLS
+extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
+                        struct task_struct *, unsigned long);
+#else
+extern int copy_thread(unsigned long, unsigned long, unsigned long,
+                        struct task_struct *);
+
+/* Architectures that haven't opted into copy_thread_tls get the tls argument
+ * via pt_regs, so ignore the tls argument passed via C. */
+static inline int copy_thread_tls(
+                unsigned long clone_flags, unsigned long sp, unsigned long arg,
+                struct task_struct *p, unsigned long tls)
+{
+        return copy_thread(clone_flags, sp, arg, p);
+}
+#endif
+extern void flush_thread(void);
+
+#ifdef CONFIG_HAVE_EXIT_THREAD
+extern void exit_thread(struct task_struct *tsk);
+#else
+static inline void exit_thread(struct task_struct *tsk)
+{
+}
+#endif
+extern void do_group_exit(int);
+
+extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
+extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
+struct task_struct *fork_idle(int);
+extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
+
+
+#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
+extern int arch_task_struct_size __read_mostly;
+#else
+# define arch_task_struct_size (sizeof(struct task_struct))
+#endif
+
+#ifdef CONFIG_VMAP_STACK
+static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
+{
+        return t->stack_vm_area;
+}
+#else
+static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
+{
+        return NULL;
+}
+#endif
+
 #endif /* _LINUX_SCHED_TASK_H */