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 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 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 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 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 } 142 143 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 } 157 158 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 } 184 185 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