1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ONIE tlv NVMEM cells provider
4 *
5 * Copyright (C) 2022 Open Compute Group ONIE
6 * Author: Miquel Raynal <miquel.raynal@bootlin.com>
7 * Based on the nvmem driver written by: Vadym Kochan <vadym.kochan@plvision.eu>
8 * Inspired by the first layout written by: Rafał Miłecki <rafal@milecki.pl>
9 */
10
11 #include <linux/crc32.h>
12 #include <linux/etherdevice.h>
13 #include <linux/nvmem-consumer.h>
14 #include <linux/nvmem-provider.h>
15 #include <linux/of.h>
16
17 #define ONIE_TLV_MAX_LEN 2048
18 #define ONIE_TLV_CRC_FIELD_SZ 6
19 #define ONIE_TLV_CRC_SZ 4
20 #define ONIE_TLV_HDR_ID "TlvInfo"
21
22 struct onie_tlv_hdr {
23 u8 id[8];
24 u8 version;
25 __be16 data_len;
26 } __packed;
27
28 struct onie_tlv {
29 u8 type;
30 u8 len;
31 } __packed;
32
onie_tlv_cell_name(u8 type)33 static const char *onie_tlv_cell_name(u8 type)
34 {
35 switch (type) {
36 case 0x21:
37 return "product-name";
38 case 0x22:
39 return "part-number";
40 case 0x23:
41 return "serial-number";
42 case 0x24:
43 return "mac-address";
44 case 0x25:
45 return "manufacture-date";
46 case 0x26:
47 return "device-version";
48 case 0x27:
49 return "label-revision";
50 case 0x28:
51 return "platform-name";
52 case 0x29:
53 return "onie-version";
54 case 0x2A:
55 return "num-macs";
56 case 0x2B:
57 return "manufacturer";
58 case 0x2C:
59 return "country-code";
60 case 0x2D:
61 return "vendor";
62 case 0x2E:
63 return "diag-version";
64 case 0x2F:
65 return "service-tag";
66 case 0xFD:
67 return "vendor-extension";
68 case 0xFE:
69 return "crc32";
70 default:
71 break;
72 }
73
74 return NULL;
75 }
76
onie_tlv_mac_read_cb(void * priv,const char * id,int index,unsigned int offset,void * buf,size_t bytes)77 static int onie_tlv_mac_read_cb(void *priv, const char *id, int index,
78 unsigned int offset, void *buf,
79 size_t bytes)
80 {
81 eth_addr_add(buf, index);
82
83 return 0;
84 }
85
onie_tlv_read_cb(u8 type,u8 * buf)86 static nvmem_cell_post_process_t onie_tlv_read_cb(u8 type, u8 *buf)
87 {
88 switch (type) {
89 case 0x24:
90 return &onie_tlv_mac_read_cb;
91 default:
92 break;
93 }
94
95 return NULL;
96 }
97
onie_tlv_add_cells(struct device * dev,struct nvmem_device * nvmem,size_t data_len,u8 * data)98 static int onie_tlv_add_cells(struct device *dev, struct nvmem_device *nvmem,
99 size_t data_len, u8 *data)
100 {
101 struct nvmem_cell_info cell = {};
102 struct device_node *layout;
103 struct onie_tlv tlv;
104 unsigned int hdr_len = sizeof(struct onie_tlv_hdr);
105 unsigned int offset = 0;
106 int ret;
107
108 layout = of_nvmem_layout_get_container(nvmem);
109 if (!layout)
110 return -ENOENT;
111
112 while (offset < data_len) {
113 memcpy(&tlv, data + offset, sizeof(tlv));
114 if (offset + tlv.len >= data_len) {
115 dev_err(dev, "Out of bounds field (0x%x bytes at 0x%x)\n",
116 tlv.len, hdr_len + offset);
117 break;
118 }
119
120 cell.name = onie_tlv_cell_name(tlv.type);
121 if (!cell.name)
122 continue;
123
124 cell.offset = hdr_len + offset + sizeof(tlv.type) + sizeof(tlv.len);
125 cell.bytes = tlv.len;
126 cell.np = of_get_child_by_name(layout, cell.name);
127 cell.read_post_process = onie_tlv_read_cb(tlv.type, data + offset + sizeof(tlv));
128
129 ret = nvmem_add_one_cell(nvmem, &cell);
130 if (ret) {
131 of_node_put(layout);
132 return ret;
133 }
134
135 offset += sizeof(tlv) + tlv.len;
136 }
137
138 of_node_put(layout);
139
140 return 0;
141 }
142
onie_tlv_hdr_is_valid(struct device * dev,struct onie_tlv_hdr * hdr)143 static bool onie_tlv_hdr_is_valid(struct device *dev, struct onie_tlv_hdr *hdr)
144 {
145 if (memcmp(hdr->id, ONIE_TLV_HDR_ID, sizeof(hdr->id))) {
146 dev_err(dev, "Invalid header\n");
147 return false;
148 }
149
150 if (hdr->version != 0x1) {
151 dev_err(dev, "Invalid version number\n");
152 return false;
153 }
154
155 return true;
156 }
157
onie_tlv_crc_is_valid(struct device * dev,size_t table_len,u8 * table)158 static bool onie_tlv_crc_is_valid(struct device *dev, size_t table_len, u8 *table)
159 {
160 struct onie_tlv crc_hdr;
161 u32 read_crc, calc_crc;
162 __be32 crc_be;
163
164 memcpy(&crc_hdr, table + table_len - ONIE_TLV_CRC_FIELD_SZ, sizeof(crc_hdr));
165 if (crc_hdr.type != 0xfe || crc_hdr.len != ONIE_TLV_CRC_SZ) {
166 dev_err(dev, "Invalid CRC field\n");
167 return false;
168 }
169
170 /* The table contains a JAMCRC, which is XOR'ed compared to the original
171 * CRC32 implementation as known in the Ethernet world.
172 */
173 memcpy(&crc_be, table + table_len - ONIE_TLV_CRC_SZ, ONIE_TLV_CRC_SZ);
174 read_crc = be32_to_cpu(crc_be);
175 calc_crc = crc32(~0, table, table_len - ONIE_TLV_CRC_SZ) ^ 0xFFFFFFFF;
176 if (read_crc != calc_crc) {
177 dev_err(dev, "Invalid CRC read: 0x%08x, expected: 0x%08x\n",
178 read_crc, calc_crc);
179 return false;
180 }
181
182 return true;
183 }
184
onie_tlv_parse_table(struct device * dev,struct nvmem_device * nvmem,struct nvmem_layout * layout)185 static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem,
186 struct nvmem_layout *layout)
187 {
188 struct onie_tlv_hdr hdr;
189 size_t table_len, data_len, hdr_len;
190 u8 *table, *data;
191 int ret;
192
193 ret = nvmem_device_read(nvmem, 0, sizeof(hdr), &hdr);
194 if (ret < 0)
195 return ret;
196
197 if (!onie_tlv_hdr_is_valid(dev, &hdr)) {
198 dev_err(dev, "Invalid ONIE TLV header\n");
199 return -EINVAL;
200 }
201
202 hdr_len = sizeof(hdr.id) + sizeof(hdr.version) + sizeof(hdr.data_len);
203 data_len = be16_to_cpu(hdr.data_len);
204 table_len = hdr_len + data_len;
205 if (table_len > ONIE_TLV_MAX_LEN) {
206 dev_err(dev, "Invalid ONIE TLV data length\n");
207 return -EINVAL;
208 }
209
210 table = devm_kmalloc(dev, table_len, GFP_KERNEL);
211 if (!table)
212 return -ENOMEM;
213
214 ret = nvmem_device_read(nvmem, 0, table_len, table);
215 if (ret != table_len)
216 return ret;
217
218 if (!onie_tlv_crc_is_valid(dev, table_len, table))
219 return -EINVAL;
220
221 data = table + hdr_len;
222 ret = onie_tlv_add_cells(dev, nvmem, data_len, data);
223 if (ret)
224 return ret;
225
226 return 0;
227 }
228
229 static const struct of_device_id onie_tlv_of_match_table[] = {
230 { .compatible = "onie,tlv-layout", },
231 {},
232 };
233 MODULE_DEVICE_TABLE(of, onie_tlv_of_match_table);
234
235 static struct nvmem_layout onie_tlv_layout = {
236 .name = "ONIE tlv layout",
237 .of_match_table = onie_tlv_of_match_table,
238 .add_cells = onie_tlv_parse_table,
239 };
240 module_nvmem_layout_driver(onie_tlv_layout);
241
242 MODULE_LICENSE("GPL");
243 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
244 MODULE_DESCRIPTION("NVMEM layout driver for Onie TLV table parsing");
245
