1 files changed, 257 insertions, 0 deletions
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
new file mode 100644
index 000000000..8e284161b
--- /dev/null
+++ b/include/linux/posix-timers.h
@@ -0,0 +1,257 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _linux_POSIX_TIMERS_H
+#define _linux_POSIX_TIMERS_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/alarmtimer.h>
+#include <linux/timerqueue.h>
+#include <linux/task_work.h>
+
+struct kernel_siginfo;
+struct task_struct;
+
+/*
+ * Bit fields within a clockid:
+ *
+ * The most significant 29 bits hold either a pid or a file descriptor.
+ *
+ * Bit 2 indicates whether a cpu clock refers to a thread or a process.
+ *
+ * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
+ *
+ * A clockid is invalid if bits 2, 1, and 0 are all set.
+ */
+#define CPUCLOCK_PID(clock)		((pid_t) ~((clock) >> 3))
+#define CPUCLOCK_PERTHREAD(clock) \
+	(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
+
+#define CPUCLOCK_PERTHREAD_MASK	4
+#define CPUCLOCK_WHICH(clock)	((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
+#define CPUCLOCK_CLOCK_MASK	3
+#define CPUCLOCK_PROF		0
+#define CPUCLOCK_VIRT		1
+#define CPUCLOCK_SCHED		2
+#define CPUCLOCK_MAX		3
+#define CLOCKFD			CPUCLOCK_MAX
+#define CLOCKFD_MASK		(CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
+
+static inline clockid_t make_process_cpuclock(const unsigned int pid,
+		const clockid_t clock)
+{
+	return ((~pid) << 3) | clock;
+}
+static inline clockid_t make_thread_cpuclock(const unsigned int tid,
+		const clockid_t clock)
+{
+	return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
+}
+
+static inline clockid_t fd_to_clockid(const int fd)
+{
+	return make_process_cpuclock((unsigned int) fd, CLOCKFD);
+}
+
+static inline int clockid_to_fd(const clockid_t clk)
+{
+	return ~(clk >> 3);
+}
+
+#ifdef CONFIG_POSIX_TIMERS
+
+/**
+ * cpu_timer - Posix CPU timer representation for k_itimer
+ * @node:	timerqueue node to queue in the task/sig
+ * @head:	timerqueue head on which this timer is queued
+ * @pid:	Pointer to target task PID
+ * @elist:	List head for the expiry list
+ * @firing:	Timer is currently firing
+ * @handling:	Pointer to the task which handles expiry
+ */
+struct cpu_timer {
+	struct timerqueue_node		node;
+	struct timerqueue_head		*head;
+	struct pid			*pid;
+	struct list_head		elist;
+	int				firing;
+	struct task_struct __rcu	*handling;
+};
+
+static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
+				     struct cpu_timer *ctmr)
+{
+	ctmr->head = head;
+	return timerqueue_add(head, &ctmr->node);
+}
+
+static inline void cpu_timer_dequeue(struct cpu_timer *ctmr)
+{
+	if (ctmr->head) {
+		timerqueue_del(ctmr->head, &ctmr->node);
+		ctmr->head = NULL;
+	}
+}
+
+static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
+{
+	return ctmr->node.expires;
+}
+
+static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
+{
+	ctmr->node.expires = exp;
+}
+
+/**
+ * posix_cputimer_base - Container per posix CPU clock
+ * @nextevt:		Earliest-expiration cache
+ * @tqhead:		timerqueue head for cpu_timers
+ */
+struct posix_cputimer_base {
+	u64			nextevt;
+	struct timerqueue_head	tqhead;
+};
+
+/**
+ * posix_cputimers - Container for posix CPU timer related data
+ * @bases:		Base container for posix CPU clocks
+ * @timers_active:	Timers are queued.
+ * @expiry_active:	Timer expiry is active. Used for
+ *			process wide timers to avoid multiple
+ *			task trying to handle expiry concurrently
+ *
+ * Used in task_struct and signal_struct
+ */
+struct posix_cputimers {
+	struct posix_cputimer_base	bases[CPUCLOCK_MAX];
+	unsigned int			timers_active;
+	unsigned int			expiry_active;
+};
+
+/**
+ * posix_cputimers_work - Container for task work based posix CPU timer expiry
+ * @work:	The task work to be scheduled
+ * @mutex:	Mutex held around expiry in context of this task work
+ * @scheduled:  @work has been scheduled already, no further processing
+ */
+struct posix_cputimers_work {
+	struct callback_head	work;
+	struct mutex		mutex;
+	unsigned int		scheduled;
+};
+
+static inline void posix_cputimers_init(struct posix_cputimers *pct)
+{
+	memset(pct, 0, sizeof(*pct));
+	pct->bases[0].nextevt = U64_MAX;
+	pct->bases[1].nextevt = U64_MAX;
+	pct->bases[2].nextevt = U64_MAX;
+}
+
+void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
+
+static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
+					       u64 runtime)
+{
+	pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
+}
+
+/* Init task static initializer */
+#define INIT_CPU_TIMERBASE(b) {						\
+	.nextevt	= U64_MAX,					\
+}
+
+#define INIT_CPU_TIMERBASES(b) {					\
+	INIT_CPU_TIMERBASE(b[0]),					\
+	INIT_CPU_TIMERBASE(b[1]),					\
+	INIT_CPU_TIMERBASE(b[2]),					\
+}
+
+#define INIT_CPU_TIMERS(s)						\
+	.posix_cputimers = {						\
+		.bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases),	\
+	},
+#else
+struct posix_cputimers { };
+struct cpu_timer { };
+#define INIT_CPU_TIMERS(s)
+static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
+static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
+					      u64 cpu_limit) { }
+#endif
+
+#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
+void clear_posix_cputimers_work(struct task_struct *p);
+void posix_cputimers_init_work(void);
+#else
+static inline void clear_posix_cputimers_work(struct task_struct *p) { }
+static inline void posix_cputimers_init_work(void) { }
+#endif
+
+#define REQUEUE_PENDING 1
+
+/**
+ * struct k_itimer - POSIX.1b interval timer structure.
+ * @list:		List head for binding the timer to signals->posix_timers
+ * @t_hash:		Entry in the posix timer hash table
+ * @it_lock:		Lock protecting the timer
+ * @kclock:		Pointer to the k_clock struct handling this timer
+ * @it_clock:		The posix timer clock id
+ * @it_id:		The posix timer id for identifying the timer
+ * @it_active:		Marker that timer is active
+ * @it_overrun:		The overrun counter for pending signals
+ * @it_overrun_last:	The overrun at the time of the last delivered signal
+ * @it_requeue_pending:	Indicator that timer waits for being requeued on
+ *			signal delivery
+ * @it_sigev_notify:	The notify word of sigevent struct for signal delivery
+ * @it_interval:	The interval for periodic timers
+ * @it_signal:		Pointer to the creators signal struct
+ * @it_pid:		The pid of the process/task targeted by the signal
+ * @it_process:		The task to wakeup on clock_nanosleep (CPU timers)
+ * @sigq:		Pointer to preallocated sigqueue
+ * @it:			Union representing the various posix timer type
+ *			internals.
+ * @rcu:		RCU head for freeing the timer.
+ */
+struct k_itimer {
+	struct list_head	list;
+	struct hlist_node	t_hash;
+	spinlock_t		it_lock;
+	const struct k_clock	*kclock;
+	clockid_t		it_clock;
+	timer_t			it_id;
+	int			it_active;
+	s64			it_overrun;
+	s64			it_overrun_last;
+	int			it_requeue_pending;
+	int			it_sigev_notify;
+	ktime_t			it_interval;
+	struct signal_struct	*it_signal;
+	union {
+		struct pid		*it_pid;
+		struct task_struct	*it_process;
+	};
+	struct sigqueue		*sigq;
+	union {
+		struct {
+			struct hrtimer	timer;
+		} real;
+		struct cpu_timer	cpu;
+		struct {
+			struct alarm	alarmtimer;
+		} alarm;
+	} it;
+	struct rcu_head		rcu;
+};
+
+void run_posix_cpu_timers(void);
+void posix_cpu_timers_exit(struct task_struct *task);
+void posix_cpu_timers_exit_group(struct task_struct *task);
+void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
+			   u64 *newval, u64 *oldval);
+
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
+
+void posixtimer_rearm(struct kernel_siginfo *info);
+#endif