1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2018 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 #ifndef	_LINUXKPI_LINUX_SCHED_H_
30 #define	_LINUXKPI_LINUX_SCHED_H_
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/proc.h>
35 #include <sys/rtprio.h>
36 #include <sys/sched.h>
37 #include <sys/sleepqueue.h>
38 #include <sys/time.h>
39 
40 #include <linux/bitmap.h>
41 #include <linux/compat.h>
42 #include <linux/completion.h>
43 #include <linux/hrtimer.h>
44 #include <linux/mm_types.h>
45 #include <linux/pid.h>
46 #include <linux/slab.h>
47 #include <linux/string.h>
48 #include <linux/spinlock.h>
49 #include <linux/time.h>
50 
51 #include <linux/sched/mm.h>
52 
53 #include <asm/atomic.h>
54 
55 #define	MAX_SCHEDULE_TIMEOUT	INT_MAX
56 
57 #define	TASK_RUNNING		0x0000
58 #define	TASK_INTERRUPTIBLE	0x0001
59 #define	TASK_UNINTERRUPTIBLE	0x0002
60 #define	TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
61 #define	TASK_WAKING		0x0100
62 #define	TASK_PARKED		0x0200
63 
64 #define	TASK_COMM_LEN		(MAXCOMLEN + 1)
65 
66 struct seq_file;
67 struct fpu_kern_ctx;
68 
69 struct work_struct;
70 struct task_struct {
71 	struct thread *task_thread;
72 	struct mm_struct *mm;
73 	linux_task_fn_t *task_fn;
74 	void   *task_data;
75 	int	task_ret;
76 	atomic_t usage;
77 	atomic_t state;
78 	atomic_t kthread_flags;
79 	pid_t	pid;	/* BSD thread ID */
80 	const char    *comm;
81 	void   *bsd_ioctl_data;
82 	unsigned bsd_ioctl_len;
83 	struct completion parked;
84 	struct completion exited;
85 #define	TS_RCU_TYPE_MAX 2
86 	TAILQ_ENTRY(task_struct) rcu_entry[TS_RCU_TYPE_MAX];
87 	int rcu_recurse[TS_RCU_TYPE_MAX];
88 	int bsd_interrupt_value;
89 	struct work_struct *work;	/* current work struct, if set */
90 	struct task_struct *group_leader;
91 	unsigned rcu_section[TS_RCU_TYPE_MAX];
92 	unsigned int fpu_ctx_level;
93 	struct fpu_kern_ctx *fpu_ctx;
94 };
95 
96 #define	current	({ \
97 	struct thread *__td = curthread; \
98 	linux_set_current(__td); \
99 	((struct task_struct *)__td->td_lkpi_task); \
100 })
101 
102 #define	task_pid_group_leader(task) (task)->task_thread->td_proc->p_pid
103 #define	task_pid(task)		((task)->pid)
104 #define	task_pid_nr(task)	((task)->pid)
105 #define	task_pid_vnr(task)	((task)->pid)
106 #define	get_pid(x)		(x)
107 #define	put_pid(x)		do { } while (0)
108 #define	current_euid()	(curthread->td_ucred->cr_uid)
109 #define	task_euid(task)	((task)->task_thread->td_ucred->cr_uid)
110 
111 #define	get_task_state(task)		atomic_read(&(task)->state)
112 #define	set_task_state(task, x)		atomic_set(&(task)->state, (x))
113 #define	__set_task_state(task, x)	((task)->state.counter = (x))
114 #define	set_current_state(x)		set_task_state(current, x)
115 #define	__set_current_state(x)		__set_task_state(current, x)
116 
117 static inline void
118 get_task_struct(struct task_struct *task)
119 {
120 	atomic_inc(&task->usage);
121 }
122 
123 static inline void
124 put_task_struct(struct task_struct *task)
125 {
126 	if (atomic_dec_and_test(&task->usage))
127 		linux_free_current(task);
128 }
129 
130 #define	cond_resched()	do { if (!cold) sched_relinquish(curthread); } while (0)
131 
132 #define	yield()		kern_yield(PRI_UNCHANGED)
133 #define	sched_yield()	sched_relinquish(curthread)
134 
135 #define	need_resched()	(curthread->td_owepreempt || \
136     td_ast_pending(curthread, TDA_SCHED))
137 
138 static inline int
139 cond_resched_lock(spinlock_t *lock)
140 {
141 
142 	if (need_resched() == 0)
143 		return (0);
144 	spin_unlock(lock);
145 	cond_resched();
146 	spin_lock(lock);
147 	return (1);
148 }
149 
150 bool linux_signal_pending(struct task_struct *task);
151 bool linux_fatal_signal_pending(struct task_struct *task);
152 bool linux_signal_pending_state(long state, struct task_struct *task);
153 void linux_send_sig(int signo, struct task_struct *task);
154 
155 #define	signal_pending(task)		linux_signal_pending(task)
156 #define	fatal_signal_pending(task)	linux_fatal_signal_pending(task)
157 #define	signal_pending_state(state, task)		\
158 	linux_signal_pending_state(state, task)
159 #define	send_sig(signo, task, priv) do {		\
160 	CTASSERT((priv) == 0);				\
161 	linux_send_sig(signo, task);			\
162 } while (0)
163 
164 int linux_schedule_timeout(int timeout);
165 
166 static inline void
167 linux_schedule_save_interrupt_value(struct task_struct *task, int value)
168 {
169 	task->bsd_interrupt_value = value;
170 }
171 
172 bool linux_task_exiting(struct task_struct *task);
173 
174 #define	current_exiting() \
175 	linux_task_exiting(current)
176 
177 static inline int
178 linux_schedule_get_interrupt_value(struct task_struct *task)
179 {
180 	int value = task->bsd_interrupt_value;
181 	task->bsd_interrupt_value = 0;
182 	return (value);
183 }
184 
185 static inline void
186 schedule(void)
187 {
188 	(void)linux_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
189 }
190 
191 #define	schedule_timeout(timeout)			\
192 	linux_schedule_timeout(timeout)
193 #define	schedule_timeout_killable(timeout)		\
194 	schedule_timeout_interruptible(timeout)
195 #define	schedule_timeout_interruptible(timeout) ({	\
196 	set_current_state(TASK_INTERRUPTIBLE);		\
197 	schedule_timeout(timeout);			\
198 })
199 #define	schedule_timeout_uninterruptible(timeout) ({	\
200 	set_current_state(TASK_UNINTERRUPTIBLE);	\
201 	schedule_timeout(timeout);			\
202 })
203 
204 #define	io_schedule()			schedule()
205 #define	io_schedule_timeout(timeout)	schedule_timeout(timeout)
206 
207 static inline uint64_t
208 local_clock(void)
209 {
210 	struct timespec ts;
211 
212 	nanotime(&ts);
213 	return ((uint64_t)ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec);
214 }
215 
216 static inline const char *
217 get_task_comm(char *buf, struct task_struct *task)
218 {
219 
220 	buf[0] = 0; /* buffer is too small */
221 	return (task->comm);
222 }
223 
224 static inline void
225 sched_set_fifo(struct task_struct *t)
226 {
227 	struct rtprio rtp;
228 
229 	rtp.prio = (RTP_PRIO_MIN + RTP_PRIO_MAX) / 2;
230 	rtp.type = RTP_PRIO_FIFO;
231 	rtp_to_pri(&rtp, t->task_thread);
232 }
233 
234 static inline void
235 sched_set_fifo_low(struct task_struct *t)
236 {
237 	struct rtprio rtp;
238 
239 	rtp.prio = RTP_PRIO_MAX;	/* lowest priority */
240 	rtp.type = RTP_PRIO_FIFO;
241 	rtp_to_pri(&rtp, t->task_thread);
242 }
243 
244 #endif	/* _LINUXKPI_LINUX_SCHED_H_ */
245