1/*
2 * Copyright (c) 2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#ifndef _SKYWALK_PACKET_PACKETQUEUE_H_
30#define _SKYWALK_PACKET_PACKETQUEUE_H_
31
32#ifdef BSD_KERNEL_PRIVATE
33
34/*
35 * Simple __kern_packet queueing system
36 * This is basically a SIMPLEQ adapted to skywalk __kern_packet use.
37 */
38#define KPKTQ_HEAD(name) \
39struct name { \
40 struct __kern_packet *kq_first; /* first packet */ \
41 struct __kern_packet **kq_last; /* addr of last next packet */ \
42 uint32_t kq_len; /* number of packets in queue */ \
43}
44
45#define KPKTQ_INIT(q) do { \
46 KPKTQ_FIRST(q) = NULL; \
47 (q)->kq_last = &KPKTQ_FIRST(q); \
48 (q)->kq_len = 0; \
49} while (0)
50
51#define KPKTQ_FINI(q) do { \
52 ASSERT(KPKTQ_EMPTY(q)); \
53 ASSERT(KPKTQ_LEN(q) == 0); \
54 KPKTQ_INIT(q); \
55} while (0)
56
57#define KPKTQ_DISPOSE(q) KPKTQ_INIT(q)
58
59#define KPKTQ_CONCAT(q1, q2) do { \
60 if (!KPKTQ_EMPTY(q2)) { \
61 *(q1)->kq_last = KPKTQ_FIRST(q2); \
62 (q1)->kq_last = (q2)->kq_last; \
63 (q1)->kq_len += (q2)->kq_len; \
64 KPKTQ_DISPOSE((q2)); \
65 } \
66} while (0)
67
68#define KPKTQ_PREPEND(q, p) do { \
69 if ((KPKTQ_NEXT(p) = KPKTQ_FIRST(q)) == NULL) { \
70 ASSERT((q)->kq_len == 0); \
71 (q)->kq_last = &KPKTQ_NEXT(p); \
72 } \
73 KPKTQ_FIRST(q) = (p); \
74 (q)->kq_len++; \
75} while (0)
76
77#define KPKTQ_ENQUEUE(q, p) do { \
78 ASSERT(KPKTQ_NEXT(p) == NULL); \
79 *(q)->kq_last = (p); \
80 (q)->kq_last = &KPKTQ_NEXT(p); \
81 (q)->kq_len++; \
82} while (0)
83
84#define KPKTQ_ENQUEUE_MULTI(q, p, n, c) do { \
85 KPKTQ_NEXT(n) = NULL; \
86 *(q)->kq_last = (p); \
87 (q)->kq_last = &KPKTQ_NEXT(n); \
88 (q)->kq_len += c; \
89} while (0)
90
91#define KPKTQ_ENQUEUE_LIST(q, p) do { \
92 uint32_t _c = 1; \
93 struct __kern_packet *_n = (p); \
94 while (__improbable(KPKTQ_NEXT(_n) != NULL)) { \
95 _c++; \
96 _n = KPKTQ_NEXT(_n); \
97 } \
98 KPKTQ_ENQUEUE_MULTI(q, p, _n, _c); \
99} while (0)
100
101#define KPKTQ_DEQUEUE(q, p) do { \
102 if (((p) = KPKTQ_FIRST(q)) != NULL) { \
103 (q)->kq_len--; \
104 if ((KPKTQ_FIRST(q) = KPKTQ_NEXT(p)) == NULL) { \
105 ASSERT((q)->kq_len == 0); \
106 (q)->kq_last = &KPKTQ_FIRST(q); \
107 } else { \
108 KPKTQ_NEXT(p) = NULL; \
109 } \
110 } \
111} while (0)
112
113#define KPKTQ_REMOVE(q, p) do { \
114 if (KPKTQ_FIRST(q) == (p)) { \
115 KPKTQ_DEQUEUE(q, p); \
116 } else { \
117 struct __kern_packet *_p = KPKTQ_FIRST(q); \
118 while (KPKTQ_NEXT(_p) != (p)) \
119 _p = KPKTQ_NEXT(_p); \
120 if ((KPKTQ_NEXT(_p) = \
121 KPKTQ_NEXT(KPKTQ_NEXT(_p))) == NULL) { \
122 (q)->kq_last = &KPKTQ_NEXT(_p); \
123 } \
124 (q)->kq_len--; \
125 KPKTQ_NEXT(p) = NULL; \
126 } \
127} while (0)
128
129#define KPKTQ_FOREACH(p, q) \
130 for ((p) = KPKTQ_FIRST(q); \
131 (p); \
132 (p) = KPKTQ_NEXT(p))
133
134#define KPKTQ_FOREACH_SAFE(p, q, tvar) \
135 for ((p) = KPKTQ_FIRST(q); \
136 (p) && ((tvar) = KPKTQ_NEXT(p), 1); \
137 (p) = (tvar))
138
139#define KPKTQ_EMPTY(q) ((q)->kq_first == NULL)
140#define KPKTQ_FIRST(q) ((q)->kq_first)
141#define KPKTQ_NEXT(p) ((p)->pkt_nextpkt)
142#define KPKTQ_LEN(q) ((q)->kq_len)
143
144/*
145 * kq_last is initialized to point to kq_first, so check if they're
146 * equal and return NULL when the list is empty. Otherwise, we need
147 * to subtract the offset of KPKTQ_NEXT (i.e. pkt_nextpkt field) to get
148 * to the base packet address to return to caller.
149 */
150#define KPKTQ_LAST(head) \
151 (((head)->kq_last == &KPKTQ_FIRST(head)) ? NULL : \
152 ((struct __kern_packet *)(void *)((char *)(head)->kq_last - \
153 (size_t)(&KPKTQ_NEXT((struct __kern_packet *)0)))))
154
155/*
156 * struct pktq serves as basic common batching data structure using KPKTQ.
157 * Elementary types of batch data structure, e.g. packet array, should be named
158 * as pkts.
159 * For instance:
160 * rx_dequeue_pktq(struct pktq *pktq);
161 * rx_dequeue_pkts(struct __kern_packet *pkts[], uint32_t n_pkts);
162 */
163KPKTQ_HEAD(pktq);
164
165#endif /* BSD_KERNEL_PRIVATE */
166#endif /* !_SKYWALK_PACKET_PACKETQUEUE_H_ */
167