xref: /freebsd/sys/dev/ocs_fc/ocs_vpd.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2017 Broadcom. All rights reserved.
3  * The term "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice,
9  *    this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  *    this list of conditions and the following disclaimer in the documentation
13  *    and/or other materials provided with the distribution.
14  *
15  * 3. Neither the name of the copyright holder nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
23  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 /**
35  * @file
36  * OCS VPD parser
37  */
38 
39 #if !defined(__OCS_VPD_H__)
40 #define __OCS_VPD_H__
41 
42 /**
43  * @brief VPD buffer structure
44  */
45 
46 typedef struct {
47 	uint8_t *buffer;
48 	uint32_t length;
49 	uint32_t offset;
50 	uint8_t checksum;
51 	} vpdbuf_t;
52 
53 /**
54  * @brief return next VPD byte
55  *
56  * Returns next VPD byte and updates accumulated checksum
57  *
58  * @param vpd pointer to vpd buffer
59  *
60  * @return returns next byte for success, or a negative error code value for failure.
61  *
62  */
63 
64 static inline int
65 vpdnext(vpdbuf_t *vpd)
66 {
67 	int rc = -1;
68 	if (vpd->offset < vpd->length) {
69 		rc = vpd->buffer[vpd->offset++];
70 		vpd->checksum += rc;
71 	}
72 	return rc;
73 }
74 
75 /**
76  * @brief return true if no more vpd buffer data
77  *
78  * return true if the vpd buffer data has been completely consumed
79  *
80  * @param vpd pointer to vpd buffer
81  *
82  * @return returns true if no more data
83  *
84  */
85 static inline int
86 vpddone(vpdbuf_t *vpd)
87 {
88 	return vpd->offset >= vpd->length;
89 }
90 /**
91  * @brief return pointer to current VPD data location
92  *
93  * Returns a pointer to the current location in the VPD data
94  *
95  * @param vpd pointer to vpd buffer
96  *
97  * @return pointer to current VPD data location
98  */
99 
100 static inline uint8_t *
101 vpdref(vpdbuf_t *vpd)
102 {
103 	return &vpd->buffer[vpd->offset];
104 }
105 
106 #define VPD_LARGE_RESOURCE_TYPE_ID_STRING_TAG	0x82
107 #define VPD_LARGE_RESOURCE_TYPE_R_TAG		0x90
108 #define VPD_LARGE_RESOURCE_TYPE_W_TAG		0x91
109 #define VPD_SMALL_RESOURCE_TYPE_END_TAG		0x78
110 
111 /**
112  * @brief find a VPD entry
113  *
114  * Finds a VPD entry given the two character code
115  *
116  * @param vpddata pointer to raw vpd data buffer
117  * @param vpddata_length length of vpddata buffer in bytes
118  * @param key key to look up
119 
120  * @return returns a pointer to the key location or NULL if not found or checksum error
121  */
122 
123 static inline uint8_t *
124 ocs_find_vpd(uint8_t *vpddata, uint32_t vpddata_length, const char *key)
125 {
126 	vpdbuf_t vpdbuf;
127 	uint8_t *pret = NULL;
128 	uint8_t c0 = key[0];
129 	uint8_t c1 = key[1];
130 
131 	vpdbuf.buffer = (uint8_t*) vpddata;
132 	vpdbuf.length = vpddata_length;
133 	vpdbuf.offset = 0;
134 	vpdbuf.checksum = 0;
135 
136 	while (!vpddone(&vpdbuf)) {
137 		int type = vpdnext(&vpdbuf);
138 		int len_lo;
139 		int len_hi;
140 		int len;
141 		int i;
142 
143 		if (type == VPD_SMALL_RESOURCE_TYPE_END_TAG) {
144 			break;
145 		}
146 
147 		len_lo = vpdnext(&vpdbuf);
148 		len_hi = vpdnext(&vpdbuf);
149 		len = len_lo + (len_hi << 8);
150 
151 		if ((type == VPD_LARGE_RESOURCE_TYPE_R_TAG) || (type == VPD_LARGE_RESOURCE_TYPE_W_TAG)) {
152 			while (len > 0) {
153 				int rc0;
154 				int rc1;
155 				int sublen;
156 				uint8_t *pstart;
157 
158 				rc0 = vpdnext(&vpdbuf);
159 				rc1 = vpdnext(&vpdbuf);
160 
161 				/* Mark this location */
162 				pstart = vpdref(&vpdbuf);
163 
164 				sublen = vpdnext(&vpdbuf);
165 
166 				/* Adjust remaining len */
167 				len -= (sublen + 3);
168 
169 				/* check for match with request */
170 				if ((c0 == rc0) && (c1 == rc1)) {
171 					pret = pstart;
172 					for (i = 0; i < sublen; i++) {
173 						vpdnext(&vpdbuf);
174 					}
175 				/* check for "RV" end */
176 				} else if ('R' == rc0 && 'V' == rc1) {
177 					/* Read the checksum */
178 					for (i = 0; i < sublen; i++) {
179 						vpdnext(&vpdbuf);
180 					}
181 
182 					/* The accumulated checksum should be zero here */
183 					if (vpdbuf.checksum != 0) {
184 						ocs_log_test(NULL, "checksum error\n");
185 						return NULL;
186 					}
187 				}
188 				else
189 					for (i = 0; i < sublen; i++) {
190 						vpdnext(&vpdbuf);
191 					}
192 			}
193 		}
194 
195 		for (i = 0; i < len; i++) {
196 			vpdnext(&vpdbuf);
197 		}
198 	}
199 
200 	return pret;
201 }
202 #endif
203