1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2015  Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Some portions of this software is derived from the
36  * https://github.com/halayli/lthread which carrys the following license.
37  *
38  * Copyright (C) 2012, Hasan Alayli <[email protected]>
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  *
49  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 #ifndef LTHREAD_SCHED_H_
63 #define LTHREAD_SCHED_H_
64 
65 #include "lthread_int.h"
66 #include "lthread_queue.h"
67 #include "lthread_objcache.h"
68 #include "lthread_diag.h"
69 #include "ctx.h"
70 
71 /*
72  * insert an lthread into a queue
73  */
74 static inline void
75 _ready_queue_insert(struct lthread_sched *sched, struct lthread *lt)
76 {
77 	if (sched == THIS_SCHED)
78 		_lthread_queue_insert_sp((THIS_SCHED)->ready, lt);
79 	else
80 		_lthread_queue_insert_mp(sched->pready, lt);
81 }
82 
83 /*
84  * remove an lthread from a queue
85  */
86 static inline struct lthread *_ready_queue_remove(struct lthread_queue *q)
87 {
88 	return _lthread_queue_remove(q);
89 }
90 
91 /**
92  * Return true if the ready queue is empty
93  */
94 static inline int _ready_queue_empty(struct lthread_queue *q)
95 {
96 	return _lthread_queue_empty(q);
97 }
98 
99 static inline uint64_t _sched_now(void)
100 {
101 	uint64_t now = rte_rdtsc();
102 
103 	if (now > (THIS_SCHED)->birth)
104 		return now - (THIS_SCHED)->birth;
105 	if (now < (THIS_SCHED)->birth)
106 		return (THIS_SCHED)->birth - now;
107 	/* never return 0 because this means sleep forever */
108 	return 1;
109 }
110 
111 static inline void
112 _affinitize(void) __attribute__ ((always_inline));
113 static inline void
114 _affinitize(void)
115 {
116 	struct lthread *lt = THIS_LTHREAD;
117 
118 	DIAG_EVENT(lt, LT_DIAG_LTHREAD_SUSPENDED, 0, 0);
119 	ctx_switch(&(THIS_SCHED)->ctx, &lt->ctx);
120 }
121 
122 static inline void
123 _suspend(void) __attribute__ ((always_inline));
124 static inline void
125 _suspend(void)
126 {
127 	struct lthread *lt = THIS_LTHREAD;
128 
129 	(THIS_SCHED)->nb_blocked_threads++;
130 	DIAG_EVENT(lt, LT_DIAG_LTHREAD_SUSPENDED, 0, 0);
131 	ctx_switch(&(THIS_SCHED)->ctx, &lt->ctx);
132 	(THIS_SCHED)->nb_blocked_threads--;
133 }
134 
135 static inline void
136 _reschedule(void) __attribute__ ((always_inline));
137 static inline void
138 _reschedule(void)
139 {
140 	struct lthread *lt = THIS_LTHREAD;
141 
142 	DIAG_EVENT(lt, LT_DIAG_LTHREAD_RESCHEDULED, 0, 0);
143 	_ready_queue_insert(THIS_SCHED, lt);
144 	ctx_switch(&(THIS_SCHED)->ctx, &lt->ctx);
145 }
146 
147 extern struct lthread_sched *schedcore[];
148 void _sched_timer_cb(struct rte_timer *tim, void *arg);
149 void _sched_shutdown(__rte_unused void *arg);
150 
151 
152 #endif				/* LTHREAD_SCHED_H_ */
153