xref: /openbmc/qemu/hw/net/rocker/rocker_tlv.h (revision b91a0fa7) 
1 /*
2  * QEMU rocker switch emulation - TLV parsing and composing
3  *
4  * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  */
16 
17 #ifndef ROCKER_TLV_H
18 #define ROCKER_TLV_H
19 
20 #define ROCKER_TLV_ALIGNTO 8U
21 #define ROCKER_TLV_ALIGN(len) \
22     (((len) + ROCKER_TLV_ALIGNTO - 1) & ~(ROCKER_TLV_ALIGNTO - 1))
23 #define ROCKER_TLV_HDRLEN ROCKER_TLV_ALIGN(sizeof(RockerTlv))
24 
25 /*
26  *  <------- ROCKER_TLV_HDRLEN -------> <--- ROCKER_TLV_ALIGN(payload) --->
27  * +-----------------------------+- - -+- - - - - - - - - - - - - - -+- - -+
28  * |             Header          | Pad |           Payload           | Pad |
29  * |          (RockerTlv)        | ing |                             | ing |
30  * +-----------------------------+- - -+- - - - - - - - - - - - - - -+- - -+
31  *  <--------------------------- tlv->len -------------------------->
32  */
33 
34 static inline RockerTlv *rocker_tlv_next(const RockerTlv *tlv, int *remaining)
35 {
36     int totlen = ROCKER_TLV_ALIGN(le16_to_cpu(tlv->len));
37 
38     *remaining -= totlen;
39     return (RockerTlv *) ((char *) tlv + totlen);
40 }
41 
42 static inline int rocker_tlv_ok(const RockerTlv *tlv, int remaining)
43 {
44     return remaining >= (int) ROCKER_TLV_HDRLEN &&
45            le16_to_cpu(tlv->len) >= ROCKER_TLV_HDRLEN &&
46            le16_to_cpu(tlv->len) <= remaining;
47 }
48 
49 #define rocker_tlv_for_each(pos, head, len, rem) \
50     for (pos = head, rem = len; \
51          rocker_tlv_ok(pos, rem); \
52          pos = rocker_tlv_next(pos, &(rem)))
53 
54 #define rocker_tlv_for_each_nested(pos, tlv, rem) \
55         rocker_tlv_for_each(pos, rocker_tlv_data(tlv), rocker_tlv_len(tlv), rem)
56 
57 static inline int rocker_tlv_size(int payload)
58 {
59     return ROCKER_TLV_HDRLEN + payload;
60 }
61 
62 static inline int rocker_tlv_total_size(int payload)
63 {
64     return ROCKER_TLV_ALIGN(rocker_tlv_size(payload));
65 }
66 
67 static inline int rocker_tlv_padlen(int payload)
68 {
69     return rocker_tlv_total_size(payload) - rocker_tlv_size(payload);
70 }
71 
72 static inline int rocker_tlv_type(const RockerTlv *tlv)
73 {
74     return le32_to_cpu(tlv->type);
75 }
76 
77 static inline void *rocker_tlv_data(const RockerTlv *tlv)
78 {
79     return (char *) tlv + ROCKER_TLV_HDRLEN;
80 }
81 
82 static inline int rocker_tlv_len(const RockerTlv *tlv)
83 {
84     return le16_to_cpu(tlv->len) - ROCKER_TLV_HDRLEN;
85 }
86 
87 static inline uint8_t rocker_tlv_get_u8(const RockerTlv *tlv)
88 {
89     return *(uint8_t *) rocker_tlv_data(tlv);
90 }
91 
92 static inline uint16_t rocker_tlv_get_u16(const RockerTlv *tlv)
93 {
94     return *(uint16_t *) rocker_tlv_data(tlv);
95 }
96 
97 static inline uint32_t rocker_tlv_get_u32(const RockerTlv *tlv)
98 {
99     return *(uint32_t *) rocker_tlv_data(tlv);
100 }
101 
102 static inline uint64_t rocker_tlv_get_u64(const RockerTlv *tlv)
103 {
104     return *(uint64_t *) rocker_tlv_data(tlv);
105 }
106 
107 static inline uint16_t rocker_tlv_get_le16(const RockerTlv *tlv)
108 {
109     return lduw_le_p(rocker_tlv_data(tlv));
110 }
111 
112 static inline uint32_t rocker_tlv_get_le32(const RockerTlv *tlv)
113 {
114     return ldl_le_p(rocker_tlv_data(tlv));
115 }
116 
117 static inline uint64_t rocker_tlv_get_le64(const RockerTlv *tlv)
118 {
119     return ldq_le_p(rocker_tlv_data(tlv));
120 }
121 
122 static inline void rocker_tlv_parse(RockerTlv **tb, int maxtype,
123                                     const char *buf, int buf_len)
124 {
125     const RockerTlv *tlv;
126     const RockerTlv *head = (const RockerTlv *) buf;
127     int rem;
128 
129     memset(tb, 0, sizeof(RockerTlv *) * (maxtype + 1));
130 
131     rocker_tlv_for_each(tlv, head, buf_len, rem) {
132         uint32_t type = rocker_tlv_type(tlv);
133 
134         if (type > 0 && type <= maxtype) {
135             tb[type] = (RockerTlv *) tlv;
136         }
137     }
138 }
139 
140 static inline void rocker_tlv_parse_nested(RockerTlv **tb, int maxtype,
141                                            const RockerTlv *tlv)
142 {
143     rocker_tlv_parse(tb, maxtype, rocker_tlv_data(tlv), rocker_tlv_len(tlv));
144 }
145 
146 static inline RockerTlv *rocker_tlv_start(char *buf, int buf_pos)
147 {
148     return (RockerTlv *) (buf + buf_pos);
149 }
150 
151 static inline void rocker_tlv_put_iov(char *buf, int *buf_pos,
152                                       int type, const struct iovec *iov,
153                                       const unsigned int iovcnt)
154 {
155     size_t len = iov_size(iov, iovcnt);
156     int total_size = rocker_tlv_total_size(len);
157     RockerTlv *tlv;
158 
159     tlv = rocker_tlv_start(buf, *buf_pos);
160     *buf_pos += total_size;
161     tlv->type = cpu_to_le32(type);
162     tlv->len = cpu_to_le16(rocker_tlv_size(len));
163     iov_to_buf(iov, iovcnt, 0, rocker_tlv_data(tlv), len);
164     memset((char *) tlv + le16_to_cpu(tlv->len), 0, rocker_tlv_padlen(len));
165 }
166 
167 static inline void rocker_tlv_put(char *buf, int *buf_pos,
168                                   int type, int len, void *data)
169 {
170     struct iovec iov = {
171         .iov_base = data,
172         .iov_len = len,
173     };
174 
175     rocker_tlv_put_iov(buf, buf_pos, type, &iov, 1);
176 }
177 
178 static inline void rocker_tlv_put_u8(char *buf, int *buf_pos,
179                                      int type, uint8_t value)
180 {
181     rocker_tlv_put(buf, buf_pos, type, sizeof(uint8_t), &value);
182 }
183 
184 static inline void rocker_tlv_put_u16(char *buf, int *buf_pos,
185                                       int type, uint16_t value)
186 {
187     rocker_tlv_put(buf, buf_pos, type, sizeof(uint16_t), &value);
188 }
189 
190 static inline void rocker_tlv_put_u32(char *buf, int *buf_pos,
191                                       int type, uint32_t value)
192 {
193     rocker_tlv_put(buf, buf_pos, type, sizeof(uint32_t), &value);
194 }
195 
196 static inline void rocker_tlv_put_u64(char *buf, int *buf_pos,
197                                       int type, uint64_t value)
198 {
199     rocker_tlv_put(buf, buf_pos, type, sizeof(uint64_t), &value);
200 }
201 
202 static inline void rocker_tlv_put_le16(char *buf, int *buf_pos,
203                                        int type, uint16_t value)
204 {
205     value = cpu_to_le16(value);
206     rocker_tlv_put(buf, buf_pos, type, sizeof(uint16_t), &value);
207 }
208 
209 static inline void rocker_tlv_put_le32(char *buf, int *buf_pos,
210                                        int type, uint32_t value)
211 {
212     value = cpu_to_le32(value);
213     rocker_tlv_put(buf, buf_pos, type, sizeof(uint32_t), &value);
214 }
215 
216 static inline void rocker_tlv_put_le64(char *buf, int *buf_pos,
217                                        int type, uint64_t value)
218 {
219     value = cpu_to_le64(value);
220     rocker_tlv_put(buf, buf_pos, type, sizeof(uint64_t), &value);
221 }
222 
223 static inline RockerTlv *rocker_tlv_nest_start(char *buf, int *buf_pos,
224                                                int type)
225 {
226     RockerTlv *start = rocker_tlv_start(buf, *buf_pos);
227 
228     rocker_tlv_put(buf, buf_pos, type, 0, NULL);
229     return start;
230 }
231 
232 static inline void rocker_tlv_nest_end(char *buf, int *buf_pos,
233                                        RockerTlv *start)
234 {
235     start->len = (char *) rocker_tlv_start(buf, *buf_pos) - (char *) start;
236 }
237 
238 static inline void rocker_tlv_nest_cancel(char *buf, int *buf_pos,
239                                           RockerTlv *start)
240 {
241     *buf_pos = (char *) start - buf;
242 }
243 
244 #endif
245