doc: move FAQ
[dpdk.git] / lib / librte_acl / acl_run_scalar.c
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
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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
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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 #include "acl_run.h"
35
36 /*
37  * Resolve priority for multiple results (scalar version).
38  * This consists comparing the priority of the current traversal with the
39  * running set of results for the packet.
40  * For each result, keep a running array of the result (rule number) and
41  * its priority for each category.
42  */
43 static inline void
44 resolve_priority_scalar(uint64_t transition, int n,
45         const struct rte_acl_ctx *ctx, struct parms *parms,
46         const struct rte_acl_match_results *p, uint32_t categories)
47 {
48         uint32_t i;
49         int32_t *saved_priority;
50         uint32_t *saved_results;
51         const int32_t *priority;
52         const uint32_t *results;
53
54         saved_results = parms[n].cmplt->results;
55         saved_priority = parms[n].cmplt->priority;
56
57         /* results and priorities for completed trie */
58         results = p[transition].results;
59         priority = p[transition].priority;
60
61         /* if this is not the first completed trie */
62         if (parms[n].cmplt->count != ctx->num_tries) {
63                 for (i = 0; i < categories; i += RTE_ACL_RESULTS_MULTIPLIER) {
64
65                         if (saved_priority[i] <= priority[i]) {
66                                 saved_priority[i] = priority[i];
67                                 saved_results[i] = results[i];
68                         }
69                         if (saved_priority[i + 1] <= priority[i + 1]) {
70                                 saved_priority[i + 1] = priority[i + 1];
71                                 saved_results[i + 1] = results[i + 1];
72                         }
73                         if (saved_priority[i + 2] <= priority[i + 2]) {
74                                 saved_priority[i + 2] = priority[i + 2];
75                                 saved_results[i + 2] = results[i + 2];
76                         }
77                         if (saved_priority[i + 3] <= priority[i + 3]) {
78                                 saved_priority[i + 3] = priority[i + 3];
79                                 saved_results[i + 3] = results[i + 3];
80                         }
81                 }
82         } else {
83                 for (i = 0; i < categories; i += RTE_ACL_RESULTS_MULTIPLIER) {
84                         saved_priority[i] = priority[i];
85                         saved_priority[i + 1] = priority[i + 1];
86                         saved_priority[i + 2] = priority[i + 2];
87                         saved_priority[i + 3] = priority[i + 3];
88
89                         saved_results[i] = results[i];
90                         saved_results[i + 1] = results[i + 1];
91                         saved_results[i + 2] = results[i + 2];
92                         saved_results[i + 3] = results[i + 3];
93                 }
94         }
95 }
96
97 static inline uint32_t
98 scan_forward(uint32_t input, uint32_t max)
99 {
100         return (input == 0) ? max : rte_bsf32(input);
101 }
102
103 static inline uint64_t
104 scalar_transition(const uint64_t *trans_table, uint64_t transition,
105         uint8_t input)
106 {
107         uint32_t addr, index, ranges, x, a, b, c;
108
109         /* break transition into component parts */
110         ranges = transition >> (sizeof(index) * CHAR_BIT);
111         index = transition & ~RTE_ACL_NODE_INDEX;
112         addr = transition ^ index;
113
114         if (index != RTE_ACL_NODE_DFA) {
115                 /* calc address for a QRANGE/SINGLE node */
116                 c = (uint32_t)input * SCALAR_QRANGE_MULT;
117                 a = ranges | SCALAR_QRANGE_MIN;
118                 a -= (c & SCALAR_QRANGE_MASK);
119                 b = c & SCALAR_QRANGE_MIN;
120                 a &= SCALAR_QRANGE_MIN;
121                 a ^= (ranges ^ b) & (a ^ b);
122                 x = scan_forward(a, 32) >> 3;
123         } else {
124                 /* calc address for a DFA node */
125                 x = ranges >> (input /
126                         RTE_ACL_DFA_GR64_SIZE * RTE_ACL_DFA_GR64_BIT);
127                 x &= UINT8_MAX;
128                 x = input - x;
129         }
130
131         addr += x;
132
133         /* pickup next transition */
134         transition = *(trans_table + addr);
135         return transition;
136 }
137
138 int
139 rte_acl_classify_scalar(const struct rte_acl_ctx *ctx, const uint8_t **data,
140         uint32_t *results, uint32_t num, uint32_t categories)
141 {
142         int n;
143         uint64_t transition0, transition1;
144         uint32_t input0, input1;
145         struct acl_flow_data flows;
146         uint64_t index_array[MAX_SEARCHES_SCALAR];
147         struct completion cmplt[MAX_SEARCHES_SCALAR];
148         struct parms parms[MAX_SEARCHES_SCALAR];
149
150         acl_set_flow(&flows, cmplt, RTE_DIM(cmplt), data, results, num,
151                 categories, ctx->trans_table);
152
153         for (n = 0; n < MAX_SEARCHES_SCALAR; n++) {
154                 cmplt[n].count = 0;
155                 index_array[n] = acl_start_next_trie(&flows, parms, n, ctx);
156         }
157
158         transition0 = index_array[0];
159         transition1 = index_array[1];
160
161         while ((transition0 | transition1) & RTE_ACL_NODE_MATCH) {
162                 transition0 = acl_match_check(transition0,
163                         0, ctx, parms, &flows, resolve_priority_scalar);
164                 transition1 = acl_match_check(transition1,
165                         1, ctx, parms, &flows, resolve_priority_scalar);
166         }
167
168         while (flows.started > 0) {
169
170                 input0 = GET_NEXT_4BYTES(parms, 0);
171                 input1 = GET_NEXT_4BYTES(parms, 1);
172
173                 for (n = 0; n < 4; n++) {
174
175                         transition0 = scalar_transition(flows.trans,
176                                 transition0, (uint8_t)input0);
177                         input0 >>= CHAR_BIT;
178
179                         transition1 = scalar_transition(flows.trans,
180                                 transition1, (uint8_t)input1);
181                         input1 >>= CHAR_BIT;
182                 }
183
184                 while ((transition0 | transition1) & RTE_ACL_NODE_MATCH) {
185                         transition0 = acl_match_check(transition0,
186                                 0, ctx, parms, &flows, resolve_priority_scalar);
187                         transition1 = acl_match_check(transition1,
188                                 1, ctx, parms, &flows, resolve_priority_scalar);
189                 }
190         }
191         return 0;
192 }