1 /* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
4 * We are making the OpenFlow specification and associated documentation
5 * (Software) available for public use and benefit with the expectation
6 * that others will use, modify and enhance the Software and contribute
7 * those enhancements back to the community. However, since we would
8 * like to make the Software available for broadest use, with as few
9 * restrictions as possible permission is hereby granted, free of
10 * charge, to any person obtaining a copy of this Software to deal in
11 * the Software under the copyrights without restriction, including
12 * without limitation the rights to use, copy, modify, merge, publish,
13 * distribute, sublicense, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
25 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
26 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
29 * The name and trademarks of copyright holder(s) may NOT be used in
30 * advertising or publicity pertaining to the Software or any
31 * derivatives without specific, written prior permission.
35 #define PORT_ARRAY_H 1
41 static inline uint16_t
42 port_array_extract_bits__(uint16_t data, int start, int count)
44 return (data >> start) & ((1u << count) - 1);
47 /* Level 1: most-significant bits. */
48 #define PORT_ARRAY_L1_BITS 5
49 #define PORT_ARRAY_L1_SHIFT (PORT_ARRAY_L3_BITS + PORT_ARRAY_L2_BITS)
50 #define PORT_ARRAY_L1_SIZE (1u << PORT_ARRAY_L1_BITS)
51 #define PORT_ARRAY_L1(IDX) \
52 port_array_extract_bits__(IDX, PORT_ARRAY_L1_SHIFT, PORT_ARRAY_L1_BITS)
54 /* Level 2: middle bits. */
55 #define PORT_ARRAY_L2_BITS 5
56 #define PORT_ARRAY_L2_SHIFT PORT_ARRAY_L3_BITS
57 #define PORT_ARRAY_L2_SIZE (1u << PORT_ARRAY_L2_BITS)
58 #define PORT_ARRAY_L2(IDX) \
59 port_array_extract_bits__(IDX, PORT_ARRAY_L2_SHIFT, PORT_ARRAY_L2_BITS)
61 /* Level 3: least-significant bits. */
62 #define PORT_ARRAY_L3_BITS 6
63 #define PORT_ARRAY_L3_SHIFT 0
64 #define PORT_ARRAY_L3_SIZE (1u << PORT_ARRAY_L3_BITS)
65 #define PORT_ARRAY_L3(IDX) \
66 port_array_extract_bits__(IDX, PORT_ARRAY_L3_SHIFT, PORT_ARRAY_L3_BITS)
68 #define PORT_ARRAY_SIZE (1u << (PORT_ARRAY_L1_BITS \
69 + PORT_ARRAY_L2_BITS \
70 + PORT_ARRAY_L3_BITS))
72 BUILD_ASSERT_DECL(PORT_ARRAY_SIZE > 0xffff);
74 /* A "sparse array" of up to 65536 elements (numbered 0...65535), implemented
75 * as a 3-level trie. Most efficient when the elements are clustered
78 struct port_array_l2 *l1[1u << PORT_ARRAY_L1_BITS];
81 struct port_array_l2 {
82 struct port_array_l3 *l2[1u << PORT_ARRAY_L2_BITS];
85 struct port_array_l3 {
86 void *l3[1u << PORT_ARRAY_L3_BITS];
89 /* Returns the value of the element numbered 'idx' in 'pa', or a null pointer
90 * if no element numbered 'idx' has been set. */
92 port_array_get(const struct port_array *pa, uint16_t idx)
94 unsigned int l1_idx = PORT_ARRAY_L1(idx);
95 unsigned int l2_idx = PORT_ARRAY_L2(idx);
96 unsigned int l3_idx = PORT_ARRAY_L3(idx);
97 return pa->l1[l1_idx]->l2[l2_idx]->l3[l3_idx];
100 void port_array_init(struct port_array *);
101 void port_array_destroy(struct port_array *);
102 void port_array_set(struct port_array *, uint16_t idx, void *);
103 void *port_array_first(const struct port_array *, unsigned int *);
104 void *port_array_next(const struct port_array *, unsigned int *);
106 #endif /* port-array.h */