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  * $FreeBSD$
30  */
31 #ifndef	_LINUXKPI_LINUX_SCHED_H_
32 #define	_LINUXKPI_LINUX_SCHED_H_
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/proc.h>
37 #include <sys/sched.h>
38 #include <sys/sleepqueue.h>
39 #include <sys/time.h>
40 
41 #include <linux/bitmap.h>
42 #include <linux/compat.h>
43 #include <linux/completion.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 <asm/atomic.h>
52 
53 #define	MAX_SCHEDULE_TIMEOUT	INT_MAX
54 
55 #define	TASK_RUNNING		0x0000
56 #define	TASK_INTERRUPTIBLE	0x0001
57 #define	TASK_UNINTERRUPTIBLE	0x0002
58 #define	TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
59 #define	TASK_WAKING		0x0100
60 #define	TASK_PARKED		0x0200
61 
62 #define	TASK_COMM_LEN		(MAXCOMLEN + 1)
63 
64 struct work_struct;
65 struct task_struct {
66 	struct thread *task_thread;
67 	struct mm_struct *mm;
68 	linux_task_fn_t *task_fn;
69 	void   *task_data;
70 	int	task_ret;
71 	atomic_t usage;
72 	atomic_t state;
73 	atomic_t kthread_flags;
74 	pid_t	pid;	/* BSD thread ID */
75 	const char    *comm;
76 	void   *bsd_ioctl_data;
77 	unsigned bsd_ioctl_len;
78 	struct completion parked;
79 	struct completion exited;
80 #define	TS_RCU_TYPE_MAX 2
81 	TAILQ_ENTRY(task_struct) rcu_entry[TS_RCU_TYPE_MAX];
82 	int rcu_recurse[TS_RCU_TYPE_MAX];
83 	int bsd_interrupt_value;
84 	struct work_struct *work;	/* current work struct, if set */
85 	struct task_struct *group_leader;
86 	unsigned rcu_section[TS_RCU_TYPE_MAX];
87 	unsigned int fpu_ctx_level;
88 };
89 
90 #define	current	({ \
91 	struct thread *__td = curthread; \
92 	linux_set_current(__td); \
93 	((struct task_struct *)__td->td_lkpi_task); \
94 })
95 
96 #define	task_pid_group_leader(task) (task)->task_thread->td_proc->p_pid
97 #define	task_pid(task)		((task)->pid)
98 #define	task_pid_nr(task)	((task)->pid)
99 #define	task_pid_vnr(task)	((task)->pid)
100 #define	get_pid(x)		(x)
101 #define	put_pid(x)		do { } while (0)
102 #define	current_euid()	(curthread->td_ucred->cr_uid)
103 #define	task_euid(task)	((task)->task_thread->td_ucred->cr_uid)
104 
105 #define	get_task_state(task)		atomic_read(&(task)->state)
106 #define	set_task_state(task, x)		atomic_set(&(task)->state, (x))
107 #define	__set_task_state(task, x)	((task)->state.counter = (x))
108 #define	set_current_state(x)		set_task_state(current, x)
109 #define	__set_current_state(x)		__set_task_state(current, x)
110 
111 static inline void
112 get_task_struct(struct task_struct *task)
113 {
114 	atomic_inc(&task->usage);
115 }
116 
117 static inline void
118 put_task_struct(struct task_struct *task)
119 {
120 	if (atomic_dec_and_test(&task->usage))
121 		linux_free_current(task);
122 }
123 
124 #define	cond_resched()	do { if (!cold) sched_relinquish(curthread); } while (0)
125 
126 #define	yield()		kern_yield(PRI_UNCHANGED)
127 #define	sched_yield()	sched_relinquish(curthread)
128 
129 #define	need_resched() (curthread->td_flags & TDF_NEEDRESCHED)
130 
131 static inline int
132 cond_resched_lock(spinlock_t *lock)
133 {
134 
135 	if (need_resched() == 0)
136 		return (0);
137 	spin_lock(lock);
138 	cond_resched();
139 	spin_unlock(lock);
140 	return (1);
141 }
142 
143 bool linux_signal_pending(struct task_struct *task);
144 bool linux_fatal_signal_pending(struct task_struct *task);
145 bool linux_signal_pending_state(long state, struct task_struct *task);
146 void linux_send_sig(int signo, struct task_struct *task);
147 
148 #define	signal_pending(task)		linux_signal_pending(task)
149 #define	fatal_signal_pending(task)	linux_fatal_signal_pending(task)
150 #define	signal_pending_state(state, task)		\
151 	linux_signal_pending_state(state, task)
152 #define	send_sig(signo, task, priv) do {		\
153 	CTASSERT((priv) == 0);				\
154 	linux_send_sig(signo, task);			\
155 } while (0)
156 
157 int linux_schedule_timeout(int timeout);
158 
159 static inline void
160 linux_schedule_save_interrupt_value(struct task_struct *task, int value)
161 {
162 	task->bsd_interrupt_value = value;
163 }
164 
165 bool linux_task_exiting(struct task_struct *task);
166 
167 #define	current_exiting() \
168 	linux_task_exiting(current)
169 
170 static inline int
171 linux_schedule_get_interrupt_value(struct task_struct *task)
172 {
173 	int value = task->bsd_interrupt_value;
174 	task->bsd_interrupt_value = 0;
175 	return (value);
176 }
177 
178 static inline void
179 schedule(void)
180 {
181 	(void)linux_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
182 }
183 
184 #define	schedule_timeout(timeout)			\
185 	linux_schedule_timeout(timeout)
186 #define	schedule_timeout_killable(timeout)		\
187 	schedule_timeout_interruptible(timeout)
188 #define	schedule_timeout_interruptible(timeout) ({	\
189 	set_current_state(TASK_INTERRUPTIBLE);		\
190 	schedule_timeout(timeout);			\
191 })
192 #define	schedule_timeout_uninterruptible(timeout) ({	\
193 	set_current_state(TASK_UNINTERRUPTIBLE);	\
194 	schedule_timeout(timeout);			\
195 })
196 
197 #define	io_schedule()			schedule()
198 #define	io_schedule_timeout(timeout)	schedule_timeout(timeout)
199 
200 static inline uint64_t
201 local_clock(void)
202 {
203 	struct timespec ts;
204 
205 	nanotime(&ts);
206 	return ((uint64_t)ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec);
207 }
208 
209 static inline const char *
210 get_task_comm(char *buf, struct task_struct *task)
211 {
212 
213 	buf[0] = 0; /* buffer is too small */
214 	return (task->comm);
215 }
216 
217 #endif	/* _LINUXKPI_LINUX_SCHED_H_ */
218