Evan Lojewski | f1e547c | 2019-03-14 14:34:33 +1030 | [diff] [blame] | 1 | // SPDX-License-Identifier: Apache-2.0 |
| 2 | // Copyright (C) 2018 IBM Corp. |
| 3 | |
| 4 | #include <fcntl.h> |
| 5 | #include <stdint.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <sys/ioctl.h> |
| 8 | #include <sys/mman.h> |
| 9 | #include <syslog.h> |
| 10 | #include <unistd.h> |
| 11 | |
| 12 | #include <algorithm> |
| 13 | |
| 14 | extern "C" { |
| 15 | #include "common.h" |
| 16 | #include "lpc.h" |
| 17 | #include "mboxd.h" |
| 18 | #include "protocol.h" |
| 19 | } |
| 20 | |
| 21 | #include "config.h" |
| 22 | |
| 23 | #include "pnor_partition.hpp" |
| 24 | #include "pnor_partition_table.hpp" |
| 25 | #include "xyz/openbmc_project/Common/error.hpp" |
| 26 | |
| 27 | #include <exception> |
| 28 | #include <memory> |
| 29 | #include <phosphor-logging/elog-errors.hpp> |
| 30 | #include <phosphor-logging/log.hpp> |
| 31 | #include <stdexcept> |
| 32 | #include <string> |
| 33 | |
Andrew Jeffery | f4bc335 | 2019-03-18 12:09:48 +1030 | [diff] [blame^] | 34 | #include "vpnor/backend.h" |
Evan Lojewski | f1e547c | 2019-03-14 14:34:33 +1030 | [diff] [blame] | 35 | |
| 36 | namespace err = sdbusplus::xyz::openbmc_project::Common::Error; |
| 37 | namespace fs = std::experimental::filesystem; |
| 38 | namespace vpnor = openpower::virtual_pnor; |
| 39 | |
| 40 | static constexpr uint32_t VPNOR_ERASE_SIZE = 4 * 1024; |
| 41 | |
| 42 | int vpnor_dev_init(struct backend* backend, void* data) |
| 43 | { |
| 44 | vpnor_partition_paths* paths = (vpnor_partition_paths*)data; |
| 45 | struct mtd_info_user mtd_info; |
| 46 | const char* filename = NULL; |
| 47 | int fd; |
| 48 | int rc = 0; |
| 49 | |
| 50 | if (!(fs::is_directory(fs::status(paths->ro_loc)) && |
| 51 | fs::is_directory(fs::status(paths->rw_loc)) && |
| 52 | fs::is_directory(fs::status(paths->prsv_loc)))) |
| 53 | { |
| 54 | return -EINVAL; |
| 55 | } |
| 56 | |
| 57 | if (backend->flash_size == 0) |
| 58 | { |
| 59 | filename = get_dev_mtd(); |
| 60 | |
| 61 | MSG_INFO("No flash size provided, using PNOR MTD size\n"); |
| 62 | |
| 63 | if (!filename) |
| 64 | { |
| 65 | MSG_ERR("Couldn't find the flash /dev/mtd partition\n"); |
| 66 | return -errno; |
| 67 | } |
| 68 | |
| 69 | MSG_DBG("Opening %s\n", filename); |
| 70 | |
| 71 | fd = open(filename, O_RDWR); |
| 72 | if (fd < 0) |
| 73 | { |
| 74 | MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n", filename, |
| 75 | strerror(errno)); |
| 76 | rc = -errno; |
| 77 | goto cleanup_filename; |
| 78 | } |
| 79 | |
| 80 | // Read the Flash Info |
| 81 | if (ioctl(fd, MEMGETINFO, &mtd_info) == -1) |
| 82 | { |
| 83 | MSG_ERR("Couldn't get information about MTD: %s\n", |
| 84 | strerror(errno)); |
| 85 | rc = -errno; |
| 86 | goto cleanup_fd; |
| 87 | } |
| 88 | |
| 89 | close(fd); |
| 90 | free((void*)filename); |
| 91 | |
| 92 | // See comment in flash.c on why |
| 93 | // this is needed. |
| 94 | backend->flash_size = mtd_info.size; |
| 95 | } |
| 96 | |
| 97 | // Hostboot requires a 4K block-size to be used in the FFS flash structure |
| 98 | backend->erase_size_shift = log_2(VPNOR_ERASE_SIZE); |
| 99 | backend->block_size_shift = backend->erase_size_shift; |
| 100 | |
| 101 | return vpnor_init(backend, paths); |
| 102 | |
| 103 | cleanup_fd: |
| 104 | close(fd); |
| 105 | |
| 106 | cleanup_filename: |
| 107 | free((void*)filename); |
| 108 | |
| 109 | return rc; |
| 110 | } |
| 111 | |
| 112 | static void vpnor_free(struct backend* backend) |
| 113 | { |
| 114 | vpnor_destroy(backend); |
| 115 | } |
| 116 | |
| 117 | /* |
| 118 | * vpnor_copy() - Copy data from the virtual pnor into a provided buffer |
| 119 | * @context: The backend context pointer |
| 120 | * @offset: The pnor offset to copy from (bytes) |
| 121 | * @mem: The buffer to copy into (must be of atleast 'size' bytes) |
| 122 | * @size: The number of bytes to copy |
| 123 | * Return: Number of bytes copied on success, otherwise negative error |
| 124 | * code. vpnor_copy will copy at most 'size' bytes, but it may |
| 125 | * copy less. |
| 126 | */ |
| 127 | static int64_t vpnor_copy(struct backend* backend, uint32_t offset, void* mem, |
| 128 | uint32_t size) |
| 129 | { |
| 130 | struct vpnor_data* priv = (struct vpnor_data*)backend->priv; |
| 131 | vpnor::partition::Table* table; |
| 132 | int rc = size; |
| 133 | |
| 134 | if (!(priv->vpnor && priv->vpnor->table)) |
| 135 | { |
| 136 | MSG_ERR("Trying to copy data with uninitialised context!\n"); |
| 137 | return -EINVAL; |
| 138 | } |
| 139 | |
| 140 | table = priv->vpnor->table; |
| 141 | |
| 142 | MSG_DBG("Copy virtual pnor to %p for size 0x%.8x from offset 0x%.8x\n", mem, |
| 143 | size, offset); |
| 144 | |
| 145 | /* The virtual PNOR partition table starts at offset 0 in the virtual |
| 146 | * pnor image. Check if host asked for an offset that lies within the |
| 147 | * partition table. |
| 148 | */ |
| 149 | size_t sz = table->size(); |
| 150 | if (offset < sz) |
| 151 | { |
| 152 | const pnor_partition_table& toc = table->getHostTable(); |
| 153 | rc = std::min(sz - offset, static_cast<size_t>(size)); |
| 154 | memcpy(mem, ((uint8_t*)&toc) + offset, rc); |
| 155 | return rc; |
| 156 | } |
| 157 | |
| 158 | try |
| 159 | { |
| 160 | vpnor::Request req(backend, offset); |
| 161 | rc = req.read(mem, size); |
| 162 | } |
| 163 | catch (vpnor::UnmappedOffset& e) |
| 164 | { |
| 165 | /* |
| 166 | * Hooo boy. Pretend that this is valid flash so we don't have |
| 167 | * discontiguous regions presented to the host. Instead, fill a window |
| 168 | * with 0xff so the 'flash' looks erased. Writes to such regions are |
| 169 | * dropped on the floor, see the implementation of vpnor_write() below. |
| 170 | */ |
| 171 | MSG_INFO("Host requested unmapped region of %" PRId32 |
| 172 | " bytes at offset 0x%" PRIx32 "\n", |
| 173 | size, offset); |
| 174 | uint32_t span = e.next - e.base; |
| 175 | rc = std::min(size, span); |
| 176 | memset(mem, 0xff, rc); |
| 177 | } |
| 178 | catch (std::exception& e) |
| 179 | { |
| 180 | MSG_ERR("%s\n", e.what()); |
| 181 | phosphor::logging::commit<err::InternalFailure>(); |
| 182 | rc = -EIO; |
| 183 | } |
| 184 | return rc; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * vpnor_write() - Write to the virtual pnor from a provided buffer |
| 189 | * @context: The backend context pointer |
| 190 | * @offset: The flash offset to write to (bytes) |
| 191 | * @buf: The buffer to write from (must be of atleast size) |
| 192 | * @size: The number of bytes to write |
| 193 | * |
| 194 | * Return: 0 on success otherwise negative error code |
| 195 | */ |
| 196 | |
| 197 | static int vpnor_write(struct backend* backend, uint32_t offset, void* buf, |
| 198 | uint32_t count) |
| 199 | { |
| 200 | assert(backend); |
| 201 | |
| 202 | struct vpnor_data* priv = (struct vpnor_data*)backend->priv; |
| 203 | |
| 204 | if (!(priv && priv->vpnor && priv->vpnor->table)) |
| 205 | { |
| 206 | MSG_ERR("Trying to write data with uninitialised context!\n"); |
| 207 | return -EINVAL; |
| 208 | } |
| 209 | |
| 210 | vpnor::partition::Table* table = priv->vpnor->table; |
| 211 | |
| 212 | try |
| 213 | { |
| 214 | const struct pnor_partition& part = table->partition(offset); |
| 215 | if (part.data.user.data[1] & PARTITION_READONLY) |
| 216 | { |
| 217 | MSG_ERR("Unreachable: Host attempted to write to read-only " |
| 218 | "partition %s\n", |
| 219 | part.data.name); |
| 220 | return -EPERM; |
| 221 | } |
| 222 | |
| 223 | MSG_DBG("Write flash @ 0x%.8x for 0x%.8x from %p\n", offset, count, |
| 224 | buf); |
| 225 | vpnor::Request req(backend, offset); |
| 226 | req.write(buf, count); |
| 227 | } |
| 228 | catch (vpnor::UnmappedOffset& e) |
| 229 | { |
| 230 | MSG_ERR("Unreachable: Host attempted to write %" PRIu32 |
| 231 | " bytes to unmapped offset 0x%" PRIx32 "\n", |
| 232 | count, offset); |
| 233 | return -EACCES; |
| 234 | } |
| 235 | catch (const vpnor::OutOfBoundsOffset& e) |
| 236 | { |
| 237 | MSG_ERR("%s\n", e.what()); |
| 238 | return -EINVAL; |
| 239 | } |
| 240 | catch (const std::exception& e) |
| 241 | { |
| 242 | MSG_ERR("%s\n", e.what()); |
| 243 | phosphor::logging::commit<err::InternalFailure>(); |
| 244 | return -EIO; |
| 245 | } |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | static bool vpnor_partition_is_readonly(const pnor_partition& part) |
| 250 | { |
| 251 | return part.data.user.data[1] & PARTITION_READONLY; |
| 252 | } |
| 253 | |
| 254 | static int vpnor_validate(struct backend* backend, uint32_t offset, |
| 255 | uint32_t size __attribute__((unused)), bool ro) |
| 256 | { |
| 257 | struct vpnor_data* priv = (struct vpnor_data*)backend->priv; |
| 258 | |
| 259 | /* All reads are allowed */ |
| 260 | if (ro) |
| 261 | { |
| 262 | return 0; |
| 263 | } |
| 264 | |
| 265 | /* Only allow write windows on regions mapped by the ToC as writeable */ |
| 266 | try |
| 267 | { |
| 268 | const pnor_partition& part = priv->vpnor->table->partition(offset); |
| 269 | if (vpnor_partition_is_readonly(part)) |
| 270 | { |
| 271 | return -EPERM; |
| 272 | } |
| 273 | } |
| 274 | catch (const openpower::virtual_pnor::UnmappedOffset& e) |
| 275 | { |
| 276 | /* |
| 277 | * Writes to unmapped areas are not meaningful, so deny the request. |
| 278 | * This removes the ability for a compromised host to abuse unused |
| 279 | * space if any data was to be persisted (which it isn't). |
| 280 | */ |
| 281 | return -EACCES; |
| 282 | } |
| 283 | |
| 284 | // Allowed. |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | /* |
| 289 | * vpnor_reset() - Reset the lpc bus mapping |
| 290 | * @context: The mbox context pointer |
| 291 | * |
| 292 | * Return 0 on success otherwise negative error code |
| 293 | */ |
| 294 | static int vpnor_reset(struct backend* backend, void* buf, uint32_t count) |
| 295 | { |
| 296 | const struct vpnor_data* priv = (const struct vpnor_data*)backend->priv; |
| 297 | int rc; |
| 298 | |
| 299 | vpnor_partition_paths paths = priv->paths; |
| 300 | |
| 301 | vpnor_destroy(backend); |
| 302 | |
| 303 | rc = vpnor_init(backend, &paths); |
| 304 | if (rc < 0) |
| 305 | return rc; |
| 306 | |
| 307 | rc = vpnor_copy_bootloader_partition(backend, buf, count); |
| 308 | if (rc < 0) |
| 309 | return rc; |
| 310 | |
| 311 | return reset_lpc_memory; |
| 312 | } |
| 313 | |
| 314 | static const struct backend_ops vpnor_ops = { |
| 315 | .init = vpnor_dev_init, |
| 316 | .free = vpnor_free, |
| 317 | .copy = vpnor_copy, |
| 318 | .set_bytemap = NULL, |
| 319 | .erase = NULL, |
| 320 | .write = vpnor_write, |
| 321 | .validate = vpnor_validate, |
| 322 | .reset = vpnor_reset, |
| 323 | }; |
| 324 | |
| 325 | struct backend backend_get_vpnor(void) |
| 326 | { |
| 327 | struct backend be = {0}; |
| 328 | |
| 329 | be.ops = &vpnor_ops; |
| 330 | |
| 331 | return be; |
| 332 | } |
| 333 | |
| 334 | int backend_probe_vpnor(struct backend* master, |
| 335 | const struct vpnor_partition_paths* paths) |
| 336 | { |
| 337 | struct backend with; |
| 338 | |
| 339 | assert(master); |
| 340 | with = backend_get_vpnor(); |
| 341 | |
| 342 | return backend_init(master, &with, (void*)paths); |
| 343 | } |