1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) IBM Corporation 2017 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/device.h> 16 #include <linux/errno.h> 17 #include <linux/fs.h> 18 #include <linux/fsi.h> 19 #include <linux/fsi-sbefifo.h> 20 #include <linux/kernel.h> 21 #include <linux/cdev.h> 22 #include <linux/module.h> 23 #include <linux/mutex.h> 24 #include <linux/of.h> 25 #include <linux/of_device.h> 26 #include <linux/of_platform.h> 27 #include <linux/sched.h> 28 #include <linux/slab.h> 29 #include <linux/uaccess.h> 30 #include <linux/delay.h> 31 #include <linux/uio.h> 32 #include <linux/vmalloc.h> 33 #include <linux/mm.h> 34 35 /* 36 * The SBEFIFO is a pipe-like FSI device for communicating with 37 * the self boot engine on POWER processors. 38 */ 39 40 #define DEVICE_NAME "sbefifo" 41 #define FSI_ENGID_SBE 0x22 42 43 /* 44 * Register layout 45 */ 46 47 /* Register banks */ 48 #define SBEFIFO_UP 0x00 /* FSI -> Host */ 49 #define SBEFIFO_DOWN 0x40 /* Host -> FSI */ 50 51 /* Per-bank registers */ 52 #define SBEFIFO_FIFO 0x00 /* The FIFO itself */ 53 #define SBEFIFO_STS 0x04 /* Status register */ 54 #define SBEFIFO_STS_PARITY_ERR 0x20000000 55 #define SBEFIFO_STS_RESET_REQ 0x02000000 56 #define SBEFIFO_STS_GOT_EOT 0x00800000 57 #define SBEFIFO_STS_MAX_XFER_LIMIT 0x00400000 58 #define SBEFIFO_STS_FULL 0x00200000 59 #define SBEFIFO_STS_EMPTY 0x00100000 60 #define SBEFIFO_STS_ECNT_MASK 0x000f0000 61 #define SBEFIFO_STS_ECNT_SHIFT 16 62 #define SBEFIFO_STS_VALID_MASK 0x0000ff00 63 #define SBEFIFO_STS_VALID_SHIFT 8 64 #define SBEFIFO_STS_EOT_MASK 0x000000ff 65 #define SBEFIFO_STS_EOT_SHIFT 0 66 #define SBEFIFO_EOT_RAISE 0x08 /* (Up only) Set End Of Transfer */ 67 #define SBEFIFO_REQ_RESET 0x0C /* (Up only) Reset Request */ 68 #define SBEFIFO_PERFORM_RESET 0x10 /* (Down only) Perform Reset */ 69 #define SBEFIFO_EOT_ACK 0x14 /* (Down only) Acknowledge EOT */ 70 #define SBEFIFO_DOWN_MAX 0x18 /* (Down only) Max transfer */ 71 72 /* CFAM GP Mailbox SelfBoot Message register */ 73 #define CFAM_GP_MBOX_SBM_ADDR 0x2824 /* Converted 0x2809 */ 74 75 #define CFAM_SBM_SBE_BOOTED 0x80000000 76 #define CFAM_SBM_SBE_ASYNC_FFDC 0x40000000 77 #define CFAM_SBM_SBE_STATE_MASK 0x00f00000 78 #define CFAM_SBM_SBE_STATE_SHIFT 20 79 80 enum sbe_state 81 { 82 SBE_STATE_UNKNOWN = 0x0, // Unkown, initial state 83 SBE_STATE_IPLING = 0x1, // IPL'ing - autonomous mode (transient) 84 SBE_STATE_ISTEP = 0x2, // ISTEP - Running IPL by steps (transient) 85 SBE_STATE_MPIPL = 0x3, // MPIPL 86 SBE_STATE_RUNTIME = 0x4, // SBE Runtime 87 SBE_STATE_DMT = 0x5, // Dead Man Timer State (transient) 88 SBE_STATE_DUMP = 0x6, // Dumping 89 SBE_STATE_FAILURE = 0x7, // Internal SBE failure 90 SBE_STATE_QUIESCE = 0x8, // Final state - needs SBE reset to get out 91 }; 92 93 /* FIFO depth */ 94 #define SBEFIFO_FIFO_DEPTH 8 95 96 /* Helpers */ 97 #define sbefifo_empty(sts) ((sts) & SBEFIFO_STS_EMPTY) 98 #define sbefifo_full(sts) ((sts) & SBEFIFO_STS_FULL) 99 #define sbefifo_parity_err(sts) ((sts) & SBEFIFO_STS_PARITY_ERR) 100 #define sbefifo_populated(sts) (((sts) & SBEFIFO_STS_ECNT_MASK) >> SBEFIFO_STS_ECNT_SHIFT) 101 #define sbefifo_vacant(sts) (SBEFIFO_FIFO_DEPTH - sbefifo_populated(sts)) 102 #define sbefifo_eot_set(sts) (((sts) & SBEFIFO_STS_EOT_MASK) >> SBEFIFO_STS_EOT_SHIFT) 103 104 /* Reset request timeout in ms */ 105 #define SBEFIFO_RESET_TIMEOUT 10000 106 107 /* Timeouts for commands in ms */ 108 #define SBEFIFO_TIMEOUT_START_CMD 10000 109 #define SBEFIFO_TIMEOUT_IN_CMD 1000 110 #define SBEFIFO_TIMEOUT_START_RSP 10000 111 #define SBEFIFO_TIMEOUT_IN_RSP 1000 112 113 /* Other constants */ 114 #define SBEFIFO_MAX_USER_CMD_LEN (0x100000 + PAGE_SIZE) 115 #define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */ 116 117 struct sbefifo { 118 uint32_t magic; 119 #define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */ 120 struct fsi_device *fsi_dev; 121 struct device dev; 122 struct cdev cdev; 123 struct mutex lock; 124 bool broken; 125 bool dead; 126 bool async_ffdc; 127 }; 128 129 struct sbefifo_user { 130 struct sbefifo *sbefifo; 131 struct mutex file_lock; 132 void *cmd_page; 133 void *pending_cmd; 134 size_t pending_len; 135 }; 136 137 static DEFINE_MUTEX(sbefifo_ffdc_mutex); 138 139 140 static void __sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc, 141 size_t ffdc_sz, bool internal) 142 { 143 int pack = 0; 144 #define FFDC_LSIZE 60 145 static char ffdc_line[FFDC_LSIZE]; 146 char *p = ffdc_line; 147 148 while (ffdc_sz) { 149 u32 w0, w1, w2, i; 150 if (ffdc_sz < 3) { 151 dev_err(dev, "SBE invalid FFDC package size %zd\n", ffdc_sz); 152 return; 153 } 154 w0 = be32_to_cpu(*(ffdc++)); 155 w1 = be32_to_cpu(*(ffdc++)); 156 w2 = be32_to_cpu(*(ffdc++)); 157 ffdc_sz -= 3; 158 if ((w0 >> 16) != 0xFFDC) { 159 dev_err(dev, "SBE invalid FFDC package signature %08x %08x %08x\n", 160 w0, w1, w2); 161 break; 162 } 163 w0 &= 0xffff; 164 if (w0 > ffdc_sz) { 165 dev_err(dev, "SBE FFDC package len %d words but only %zd remaining\n", 166 w0, ffdc_sz); 167 w0 = ffdc_sz; 168 break; 169 } 170 if (internal) { 171 dev_warn(dev, "+---- SBE FFDC package %d for async err -----+\n", 172 pack++); 173 } else { 174 dev_warn(dev, "+---- SBE FFDC package %d for cmd %02x:%02x -----+\n", 175 pack++, (w1 >> 8) & 0xff, w1 & 0xff); 176 } 177 dev_warn(dev, "| Response code: %08x |\n", w2); 178 dev_warn(dev, "|-------------------------------------------|\n"); 179 for (i = 0; i < w0; i++) { 180 if ((i & 3) == 0) { 181 p = ffdc_line; 182 p += sprintf(p, "| %04x:", i << 4); 183 } 184 p += sprintf(p, " %08x", be32_to_cpu(*(ffdc++))); 185 ffdc_sz--; 186 if ((i & 3) == 3 || i == (w0 - 1)) { 187 while ((i & 3) < 3) { 188 p += sprintf(p, " "); 189 i++; 190 } 191 dev_warn(dev, "%s |\n", ffdc_line); 192 } 193 } 194 dev_warn(dev, "+-------------------------------------------+\n"); 195 } 196 } 197 198 static void sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc, 199 size_t ffdc_sz, bool internal) 200 { 201 mutex_lock(&sbefifo_ffdc_mutex); 202 __sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, internal); 203 mutex_unlock(&sbefifo_ffdc_mutex); 204 } 205 206 int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response, 207 size_t resp_len, size_t *data_len) 208 { 209 u32 dh, s0, s1; 210 size_t ffdc_sz; 211 212 if (resp_len < 3) { 213 pr_debug("sbefifo: cmd %04x, response too small: %zd\n", 214 cmd, resp_len); 215 return -ENXIO; 216 } 217 dh = be32_to_cpu(response[resp_len - 1]); 218 if (dh > resp_len || dh < 3) { 219 dev_err(dev, "SBE cmd %02x:%02x status offset out of range: %d/%zd\n", 220 cmd >> 8, cmd & 0xff, dh, resp_len); 221 return -ENXIO; 222 } 223 s0 = be32_to_cpu(response[resp_len - dh]); 224 s1 = be32_to_cpu(response[resp_len - dh + 1]); 225 if (((s0 >> 16) != 0xC0DE) || ((s0 & 0xffff) != cmd)) { 226 dev_err(dev, "SBE cmd %02x:%02x, status signature invalid: 0x%08x 0x%08x\n", 227 cmd >> 8, cmd & 0xff, s0, s1); 228 return -ENXIO; 229 } 230 if (s1 != 0) { 231 ffdc_sz = dh - 3; 232 dev_warn(dev, "SBE error cmd %02x:%02x status=%04x:%04x\n", 233 cmd >> 8, cmd & 0xff, s1 >> 16, s1 & 0xffff); 234 if (ffdc_sz) 235 sbefifo_dump_ffdc(dev, &response[resp_len - dh + 2], 236 ffdc_sz, false); 237 } 238 if (data_len) 239 *data_len = resp_len - dh; 240 241 /* 242 * Primary status don't have the top bit set, so can't be confused with 243 * Linux negative error codes, so return the status word whole. 244 */ 245 return s1; 246 } 247 EXPORT_SYMBOL_GPL(sbefifo_parse_status); 248 249 static int sbefifo_regr(struct sbefifo *sbefifo, int reg, u32 *word) 250 { 251 __be32 raw_word; 252 int rc; 253 254 rc = fsi_device_read(sbefifo->fsi_dev, reg, &raw_word, 255 sizeof(raw_word)); 256 if (rc) 257 return rc; 258 259 *word = be32_to_cpu(raw_word); 260 261 return 0; 262 } 263 264 static int sbefifo_regw(struct sbefifo *sbefifo, int reg, u32 word) 265 { 266 __be32 raw_word = cpu_to_be32(word); 267 268 return fsi_device_write(sbefifo->fsi_dev, reg, &raw_word, 269 sizeof(raw_word)); 270 } 271 272 static int sbefifo_check_sbe_state(struct sbefifo *sbefifo) 273 { 274 __be32 raw_word; 275 u32 sbm; 276 int rc; 277 278 rc = fsi_slave_read(sbefifo->fsi_dev->slave, CFAM_GP_MBOX_SBM_ADDR, 279 &raw_word, sizeof(raw_word)); 280 if (rc) 281 return rc; 282 sbm = be32_to_cpu(raw_word); 283 284 /* SBE booted at all ? */ 285 if (!(sbm & CFAM_SBM_SBE_BOOTED)) 286 return -ESHUTDOWN; 287 288 /* Check its state */ 289 switch ((sbm & CFAM_SBM_SBE_STATE_MASK) >> CFAM_SBM_SBE_STATE_SHIFT) { 290 case SBE_STATE_UNKNOWN: 291 return -ESHUTDOWN; 292 case SBE_STATE_DMT: 293 return -EBUSY; 294 case SBE_STATE_IPLING: 295 case SBE_STATE_ISTEP: 296 case SBE_STATE_MPIPL: 297 case SBE_STATE_RUNTIME: 298 case SBE_STATE_DUMP: /* Not sure about that one */ 299 break; 300 case SBE_STATE_FAILURE: 301 case SBE_STATE_QUIESCE: 302 return -ESHUTDOWN; 303 } 304 305 /* Is there async FFDC available ? Remember it */ 306 if (sbm & CFAM_SBM_SBE_ASYNC_FFDC) 307 sbefifo->async_ffdc = true; 308 309 return 0; 310 } 311 312 /* Don't flip endianness of data to/from FIFO, just pass through. */ 313 static int sbefifo_down_read(struct sbefifo *sbefifo, __be32 *word) 314 { 315 return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word, 316 sizeof(*word)); 317 } 318 319 static int sbefifo_up_write(struct sbefifo *sbefifo, __be32 word) 320 { 321 return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word, 322 sizeof(word)); 323 } 324 325 static int sbefifo_request_reset(struct sbefifo *sbefifo) 326 { 327 struct device *dev = &sbefifo->fsi_dev->dev; 328 u32 status, timeout; 329 int rc; 330 331 dev_dbg(dev, "Requesting FIFO reset\n"); 332 333 /* Mark broken first, will be cleared if reset succeeds */ 334 sbefifo->broken = true; 335 336 /* Send reset request */ 337 rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1); 338 if (rc) { 339 dev_err(dev, "Sending reset request failed, rc=%d\n", rc); 340 return rc; 341 } 342 343 /* Wait for it to complete */ 344 for (timeout = 0; timeout < SBEFIFO_RESET_TIMEOUT; timeout++) { 345 rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status); 346 if (rc) { 347 dev_err(dev, "Failed to read UP fifo status during reset" 348 " , rc=%d\n", rc); 349 return rc; 350 } 351 352 if (!(status & SBEFIFO_STS_RESET_REQ)) { 353 dev_dbg(dev, "FIFO reset done\n"); 354 sbefifo->broken = false; 355 return 0; 356 } 357 358 msleep(1); 359 } 360 dev_err(dev, "FIFO reset timed out\n"); 361 362 return -ETIMEDOUT; 363 } 364 365 static int sbefifo_cleanup_hw(struct sbefifo *sbefifo) 366 { 367 struct device *dev = &sbefifo->fsi_dev->dev; 368 u32 up_status, down_status; 369 bool need_reset = false; 370 int rc; 371 372 rc = sbefifo_check_sbe_state(sbefifo); 373 if (rc) { 374 dev_dbg(dev, "SBE state=%d\n", rc); 375 return rc; 376 } 377 378 /* If broken, we don't need to look at status, go straight to reset */ 379 if (sbefifo->broken) 380 goto do_reset; 381 382 rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up_status); 383 if (rc) { 384 dev_err(dev, "Cleanup: Reading UP status failed, rc=%d\n", rc); 385 386 /* Will try reset again on next attempt at using it */ 387 sbefifo->broken = true; 388 return rc; 389 } 390 391 rc = sbefifo_regr(sbefifo, SBEFIFO_DOWN | SBEFIFO_STS, &down_status); 392 if (rc) { 393 dev_err(dev, "Cleanup: Reading DOWN status failed, rc=%d\n", rc); 394 395 /* Will try reset again on next attempt at using it */ 396 sbefifo->broken = true; 397 return rc; 398 } 399 400 /* The FIFO already contains a reset request from the SBE ? */ 401 if (down_status & SBEFIFO_STS_RESET_REQ) { 402 dev_info(dev, "Cleanup: FIFO reset request set, resetting\n"); 403 rc = sbefifo_regw(sbefifo, SBEFIFO_UP, SBEFIFO_PERFORM_RESET); 404 if (rc) { 405 sbefifo->broken = true; 406 dev_err(dev, "Cleanup: Reset reg write failed, rc=%d\n", rc); 407 return rc; 408 } 409 sbefifo->broken = false; 410 return 0; 411 } 412 413 /* Parity error on either FIFO ? */ 414 if ((up_status | down_status) & SBEFIFO_STS_PARITY_ERR) 415 need_reset = true; 416 417 /* Either FIFO not empty ? */ 418 if (!((up_status & down_status) & SBEFIFO_STS_EMPTY)) 419 need_reset = true; 420 421 if (!need_reset) 422 return 0; 423 424 dev_info(dev, "Cleanup: FIFO not clean (up=0x%08x down=0x%08x)\n", 425 up_status, down_status); 426 427 do_reset: 428 429 /* Mark broken, will be cleared if/when reset succeeds */ 430 return sbefifo_request_reset(sbefifo); 431 } 432 433 static int sbefifo_wait(struct sbefifo *sbefifo, bool up, 434 u32 *status, unsigned long timeout) 435 { 436 struct device *dev = &sbefifo->fsi_dev->dev; 437 unsigned long end_time; 438 bool ready = false; 439 u32 addr, sts = 0; 440 int rc; 441 442 dev_vdbg(dev, "Wait on %s fifo...\n", up ? "up" : "down"); 443 444 addr = (up ? SBEFIFO_UP : SBEFIFO_DOWN) | SBEFIFO_STS; 445 446 end_time = jiffies + timeout; 447 while (!time_after(jiffies, end_time)) { 448 cond_resched(); 449 rc = sbefifo_regr(sbefifo, addr, &sts); 450 if (rc < 0) { 451 dev_err(dev, "FSI error %d reading status register\n", rc); 452 return rc; 453 } 454 if (!up && sbefifo_parity_err(sts)) { 455 dev_err(dev, "Parity error in DOWN FIFO\n"); 456 return -ENXIO; 457 } 458 ready = !(up ? sbefifo_full(sts) : sbefifo_empty(sts)); 459 if (ready) 460 break; 461 } 462 if (!ready) { 463 dev_err(dev, "%s FIFO Timeout ! status=%08x\n", up ? "UP" : "DOWN", sts); 464 return -ETIMEDOUT; 465 } 466 dev_vdbg(dev, "End of wait status: %08x\n", sts); 467 468 *status = sts; 469 470 return 0; 471 } 472 473 static int sbefifo_send_command(struct sbefifo *sbefifo, 474 const __be32 *command, size_t cmd_len) 475 { 476 struct device *dev = &sbefifo->fsi_dev->dev; 477 size_t len, chunk, vacant = 0, remaining = cmd_len; 478 unsigned long timeout; 479 u32 status; 480 int rc; 481 482 dev_vdbg(dev, "sending command (%zd words, cmd=%04x)\n", 483 cmd_len, be32_to_cpu(command[1])); 484 485 /* As long as there's something to send */ 486 timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_CMD); 487 while (remaining) { 488 /* Wait for room in the FIFO */ 489 rc = sbefifo_wait(sbefifo, true, &status, timeout); 490 if (rc < 0) 491 return rc; 492 timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_CMD); 493 494 vacant = sbefifo_vacant(status); 495 len = chunk = min(vacant, remaining); 496 497 dev_vdbg(dev, " status=%08x vacant=%zd chunk=%zd\n", 498 status, vacant, chunk); 499 500 /* Write as much as we can */ 501 while (len--) { 502 rc = sbefifo_up_write(sbefifo, *(command++)); 503 if (rc) { 504 dev_err(dev, "FSI error %d writing UP FIFO\n", rc); 505 return rc; 506 } 507 } 508 remaining -= chunk; 509 vacant -= chunk; 510 } 511 512 /* If there's no room left, wait for some to write EOT */ 513 if (!vacant) { 514 rc = sbefifo_wait(sbefifo, true, &status, timeout); 515 if (rc) 516 return rc; 517 } 518 519 /* Send an EOT */ 520 rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE, 0); 521 if (rc) 522 dev_err(dev, "FSI error %d writing EOT\n", rc); 523 return rc; 524 } 525 526 static int sbefifo_read_response(struct sbefifo *sbefifo, struct iov_iter *response) 527 { 528 struct device *dev = &sbefifo->fsi_dev->dev; 529 u32 status, eot_set; 530 unsigned long timeout; 531 bool overflow = false; 532 __be32 data; 533 size_t len; 534 int rc; 535 536 dev_vdbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response)); 537 538 timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_RSP); 539 for (;;) { 540 /* Grab FIFO status (this will handle parity errors) */ 541 rc = sbefifo_wait(sbefifo, false, &status, timeout); 542 if (rc < 0) 543 return rc; 544 timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP); 545 546 /* Decode status */ 547 len = sbefifo_populated(status); 548 eot_set = sbefifo_eot_set(status); 549 550 dev_vdbg(dev, " chunk size %zd eot_set=0x%x\n", len, eot_set); 551 552 /* Go through the chunk */ 553 while(len--) { 554 /* Read the data */ 555 rc = sbefifo_down_read(sbefifo, &data); 556 if (rc < 0) 557 return rc; 558 559 /* Was it an EOT ? */ 560 if (eot_set & 0x80) { 561 /* 562 * There should be nothing else in the FIFO, 563 * if there is, mark broken, this will force 564 * a reset on next use, but don't fail the 565 * command. 566 */ 567 if (len) { 568 dev_warn(dev, "FIFO read hit" 569 " EOT with still %zd data\n", 570 len); 571 sbefifo->broken = true; 572 } 573 574 /* We are done */ 575 rc = sbefifo_regw(sbefifo, 576 SBEFIFO_DOWN | SBEFIFO_EOT_ACK, 0); 577 578 /* 579 * If that write fail, still complete the request but mark 580 * the fifo as broken for subsequent reset (not much else 581 * we can do here). 582 */ 583 if (rc) { 584 dev_err(dev, "FSI error %d ack'ing EOT\n", rc); 585 sbefifo->broken = true; 586 } 587 588 /* Tell whether we overflowed */ 589 return overflow ? -EOVERFLOW : 0; 590 } 591 592 /* Store it if there is room */ 593 if (iov_iter_count(response) >= sizeof(__be32)) { 594 if (copy_to_iter(&data, sizeof(__be32), response) < sizeof(__be32)) 595 return -EFAULT; 596 } else { 597 dev_vdbg(dev, "Response overflowed !\n"); 598 599 overflow = true; 600 } 601 602 /* Next EOT bit */ 603 eot_set <<= 1; 604 } 605 } 606 /* Shouldn't happen */ 607 return -EIO; 608 } 609 610 static int sbefifo_do_command(struct sbefifo *sbefifo, 611 const __be32 *command, size_t cmd_len, 612 struct iov_iter *response) 613 { 614 /* Try sending the command */ 615 int rc = sbefifo_send_command(sbefifo, command, cmd_len); 616 if (rc) 617 return rc; 618 619 /* Now, get the response */ 620 return sbefifo_read_response(sbefifo, response); 621 } 622 623 static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo) 624 { 625 struct device *dev = &sbefifo->fsi_dev->dev; 626 struct iov_iter ffdc_iter; 627 struct kvec ffdc_iov; 628 __be32 *ffdc; 629 size_t ffdc_sz; 630 __be32 cmd[2]; 631 int rc; 632 633 sbefifo->async_ffdc = false; 634 ffdc = vmalloc(SBEFIFO_MAX_FFDC_SIZE); 635 if (!ffdc) { 636 dev_err(dev, "Failed to allocate SBE FFDC buffer\n"); 637 return; 638 } 639 ffdc_iov.iov_base = ffdc; 640 ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE; 641 iov_iter_kvec(&ffdc_iter, WRITE, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE); 642 cmd[0] = cpu_to_be32(2); 643 cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC); 644 rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter); 645 if (rc != 0) { 646 dev_err(dev, "Error %d retrieving SBE FFDC\n", rc); 647 goto bail; 648 } 649 ffdc_sz = SBEFIFO_MAX_FFDC_SIZE - iov_iter_count(&ffdc_iter); 650 ffdc_sz /= sizeof(__be32); 651 rc = sbefifo_parse_status(dev, SBEFIFO_CMD_GET_SBE_FFDC, ffdc, 652 ffdc_sz, &ffdc_sz); 653 if (rc != 0) { 654 dev_err(dev, "Error %d decoding SBE FFDC\n", rc); 655 goto bail; 656 } 657 if (ffdc_sz > 0) 658 sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, true); 659 bail: 660 vfree(ffdc); 661 662 } 663 664 static int __sbefifo_submit(struct sbefifo *sbefifo, 665 const __be32 *command, size_t cmd_len, 666 struct iov_iter *response) 667 { 668 struct device *dev = &sbefifo->fsi_dev->dev; 669 int rc; 670 671 if (sbefifo->dead) 672 return -ENODEV; 673 674 if (cmd_len < 2 || be32_to_cpu(command[0]) != cmd_len) { 675 dev_vdbg(dev, "Invalid command len %zd (header: %d)\n", 676 cmd_len, be32_to_cpu(command[0])); 677 return -EINVAL; 678 } 679 680 /* First ensure the HW is in a clean state */ 681 rc = sbefifo_cleanup_hw(sbefifo); 682 if (rc) 683 return rc; 684 685 /* Look for async FFDC first if any */ 686 if (sbefifo->async_ffdc) 687 sbefifo_collect_async_ffdc(sbefifo); 688 689 rc = sbefifo_do_command(sbefifo, command, cmd_len, response); 690 if (rc != 0 && rc != -EOVERFLOW) 691 goto fail; 692 return rc; 693 fail: 694 /* 695 * On failure, attempt a reset. Ignore the result, it will mark 696 * the fifo broken if the reset fails 697 */ 698 sbefifo_request_reset(sbefifo); 699 700 /* Return original error */ 701 return rc; 702 } 703 704 /** 705 * sbefifo_submit() - Submit and SBE fifo command and receive response 706 * @dev: The sbefifo device 707 * @command: The raw command data 708 * @cmd_len: The command size (in 32-bit words) 709 * @response: The output response buffer 710 * @resp_len: In: Response buffer size, Out: Response size 711 * 712 * This will perform the entire operation. If the reponse buffer 713 * overflows, returns -EOVERFLOW 714 */ 715 int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len, 716 __be32 *response, size_t *resp_len) 717 { 718 struct sbefifo *sbefifo; 719 struct iov_iter resp_iter; 720 struct kvec resp_iov; 721 size_t rbytes; 722 int rc; 723 724 if (!dev) 725 return -ENODEV; 726 sbefifo = dev_get_drvdata(dev); 727 if (!sbefifo) 728 return -ENODEV; 729 if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC)) 730 return -ENODEV; 731 if (!resp_len || !command || !response) 732 return -EINVAL; 733 734 /* Prepare iov iterator */ 735 rbytes = (*resp_len) * sizeof(__be32); 736 resp_iov.iov_base = response; 737 resp_iov.iov_len = rbytes; 738 iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes); 739 740 /* Perform the command */ 741 mutex_lock(&sbefifo->lock); 742 rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter); 743 mutex_unlock(&sbefifo->lock); 744 745 /* Extract the response length */ 746 rbytes -= iov_iter_count(&resp_iter); 747 *resp_len = rbytes / sizeof(__be32); 748 749 return rc; 750 } 751 EXPORT_SYMBOL_GPL(sbefifo_submit); 752 753 /* 754 * Char device interface 755 */ 756 757 static void sbefifo_release_command(struct sbefifo_user *user) 758 { 759 if (is_vmalloc_addr(user->pending_cmd)) 760 vfree(user->pending_cmd); 761 user->pending_cmd = NULL; 762 user->pending_len = 0; 763 } 764 765 static int sbefifo_user_open(struct inode *inode, struct file *file) 766 { 767 struct sbefifo *sbefifo = container_of(inode->i_cdev, struct sbefifo, cdev); 768 struct sbefifo_user *user; 769 770 user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL); 771 if (!user) 772 return -ENOMEM; 773 774 file->private_data = user; 775 user->sbefifo = sbefifo; 776 user->cmd_page = (void *)__get_free_page(GFP_KERNEL); 777 if (!user->cmd_page) { 778 kfree(user); 779 return -ENOMEM; 780 } 781 mutex_init(&user->file_lock); 782 783 return 0; 784 } 785 786 static ssize_t sbefifo_user_read(struct file *file, char __user *buf, 787 size_t len, loff_t *offset) 788 { 789 struct sbefifo_user *user = file->private_data; 790 struct sbefifo *sbefifo; 791 struct iov_iter resp_iter; 792 struct iovec resp_iov; 793 size_t cmd_len; 794 int rc; 795 796 if (!user) 797 return -EINVAL; 798 sbefifo = user->sbefifo; 799 if (len & 3) 800 return -EINVAL; 801 802 mutex_lock(&user->file_lock); 803 804 /* Cronus relies on -EAGAIN after a short read */ 805 if (user->pending_len == 0) { 806 rc = -EAGAIN; 807 goto bail; 808 } 809 if (user->pending_len < 8) { 810 rc = -EINVAL; 811 goto bail; 812 } 813 cmd_len = user->pending_len >> 2; 814 815 /* Prepare iov iterator */ 816 resp_iov.iov_base = buf; 817 resp_iov.iov_len = len; 818 iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len); 819 820 /* Perform the command */ 821 mutex_lock(&sbefifo->lock); 822 rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter); 823 mutex_unlock(&sbefifo->lock); 824 if (rc < 0) 825 goto bail; 826 827 /* Extract the response length */ 828 rc = len - iov_iter_count(&resp_iter); 829 bail: 830 sbefifo_release_command(user); 831 mutex_unlock(&user->file_lock); 832 return rc; 833 } 834 835 static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, 836 size_t len, loff_t *offset) 837 { 838 struct sbefifo_user *user = file->private_data; 839 struct sbefifo *sbefifo; 840 int rc = len; 841 842 if (!user) 843 return -EINVAL; 844 sbefifo = user->sbefifo; 845 if (len > SBEFIFO_MAX_USER_CMD_LEN) 846 return -EINVAL; 847 if (len & 3) 848 return -EINVAL; 849 850 mutex_lock(&user->file_lock); 851 852 /* Can we use the pre-allocate buffer ? If not, allocate */ 853 if (len <= PAGE_SIZE) 854 user->pending_cmd = user->cmd_page; 855 else 856 user->pending_cmd = vmalloc(len); 857 if (!user->pending_cmd) { 858 rc = -ENOMEM; 859 goto bail; 860 } 861 862 /* Copy the command into the staging buffer */ 863 if (copy_from_user(user->pending_cmd, buf, len)) { 864 rc = -EFAULT; 865 goto bail; 866 } 867 868 /* Check for the magic reset command */ 869 if (len == 4 && be32_to_cpu(*(__be32 *)user->pending_cmd) == 870 SBEFIFO_RESET_MAGIC) { 871 872 /* Clear out any pending command */ 873 user->pending_len = 0; 874 875 /* Trigger reset request */ 876 mutex_lock(&sbefifo->lock); 877 rc = sbefifo_request_reset(user->sbefifo); 878 mutex_unlock(&sbefifo->lock); 879 if (rc == 0) 880 rc = 4; 881 goto bail; 882 } 883 884 /* Update the staging buffer size */ 885 user->pending_len = len; 886 bail: 887 if (!user->pending_len) 888 sbefifo_release_command(user); 889 890 mutex_unlock(&user->file_lock); 891 892 /* And that's it, we'll issue the command on a read */ 893 return rc; 894 } 895 896 static int sbefifo_user_release(struct inode *inode, struct file *file) 897 { 898 struct sbefifo_user *user = file->private_data; 899 900 if (!user) 901 return -EINVAL; 902 903 sbefifo_release_command(user); 904 free_page((unsigned long)user->cmd_page); 905 kfree(user); 906 907 return 0; 908 } 909 910 static const struct file_operations sbefifo_fops = { 911 .owner = THIS_MODULE, 912 .open = sbefifo_user_open, 913 .read = sbefifo_user_read, 914 .write = sbefifo_user_write, 915 .release = sbefifo_user_release, 916 }; 917 918 static void sbefifo_free(struct device *dev) 919 { 920 struct sbefifo *sbefifo = container_of(dev, struct sbefifo, dev); 921 922 put_device(&sbefifo->fsi_dev->dev); 923 kfree(sbefifo); 924 } 925 926 /* 927 * Probe/remove 928 */ 929 930 static int sbefifo_probe(struct device *dev) 931 { 932 struct fsi_device *fsi_dev = to_fsi_dev(dev); 933 struct sbefifo *sbefifo; 934 struct device_node *np; 935 struct platform_device *child; 936 char child_name[32]; 937 int rc, didx, child_idx = 0; 938 939 dev_dbg(dev, "Found sbefifo device\n"); 940 941 sbefifo = kzalloc(sizeof(*sbefifo), GFP_KERNEL); 942 if (!sbefifo) 943 return -ENOMEM; 944 945 /* Grab a reference to the device (parent of our cdev), we'll drop it later */ 946 if (!get_device(dev)) { 947 kfree(sbefifo); 948 return -ENODEV; 949 } 950 951 sbefifo->magic = SBEFIFO_MAGIC; 952 sbefifo->fsi_dev = fsi_dev; 953 dev_set_drvdata(dev, sbefifo); 954 mutex_init(&sbefifo->lock); 955 956 /* 957 * Try cleaning up the FIFO. If this fails, we still register the 958 * driver and will try cleaning things up again on the next access. 959 */ 960 rc = sbefifo_cleanup_hw(sbefifo); 961 if (rc && rc != -ESHUTDOWN) 962 dev_err(dev, "Initial HW cleanup failed, will retry later\n"); 963 964 /* Create chardev for userspace access */ 965 sbefifo->dev.type = &fsi_cdev_type; 966 sbefifo->dev.parent = dev; 967 sbefifo->dev.release = sbefifo_free; 968 device_initialize(&sbefifo->dev); 969 970 /* Allocate a minor in the FSI space */ 971 rc = fsi_get_new_minor(fsi_dev, fsi_dev_sbefifo, &sbefifo->dev.devt, &didx); 972 if (rc) 973 goto err; 974 975 dev_set_name(&sbefifo->dev, "sbefifo%d", didx); 976 cdev_init(&sbefifo->cdev, &sbefifo_fops); 977 rc = cdev_device_add(&sbefifo->cdev, &sbefifo->dev); 978 if (rc) { 979 dev_err(dev, "Error %d creating char device %s\n", 980 rc, dev_name(&sbefifo->dev)); 981 goto err_free_minor; 982 } 983 984 /* Create platform devs for dts child nodes (occ, etc) */ 985 for_each_available_child_of_node(dev->of_node, np) { 986 snprintf(child_name, sizeof(child_name), "%s-dev%d", 987 dev_name(&sbefifo->dev), child_idx++); 988 child = of_platform_device_create(np, child_name, dev); 989 if (!child) 990 dev_warn(dev, "failed to create child %s dev\n", 991 child_name); 992 } 993 994 return 0; 995 err_free_minor: 996 fsi_free_minor(sbefifo->dev.devt); 997 err: 998 put_device(&sbefifo->dev); 999 return rc; 1000 } 1001 1002 static int sbefifo_unregister_child(struct device *dev, void *data) 1003 { 1004 struct platform_device *child = to_platform_device(dev); 1005 1006 of_device_unregister(child); 1007 if (dev->of_node) 1008 of_node_clear_flag(dev->of_node, OF_POPULATED); 1009 1010 return 0; 1011 } 1012 1013 static int sbefifo_remove(struct device *dev) 1014 { 1015 struct sbefifo *sbefifo = dev_get_drvdata(dev); 1016 1017 dev_dbg(dev, "Removing sbefifo device...\n"); 1018 1019 mutex_lock(&sbefifo->lock); 1020 sbefifo->dead = true; 1021 mutex_unlock(&sbefifo->lock); 1022 1023 cdev_device_del(&sbefifo->cdev, &sbefifo->dev); 1024 fsi_free_minor(sbefifo->dev.devt); 1025 device_for_each_child(dev, NULL, sbefifo_unregister_child); 1026 put_device(&sbefifo->dev); 1027 1028 return 0; 1029 } 1030 1031 static const struct fsi_device_id sbefifo_ids[] = { 1032 { 1033 .engine_type = FSI_ENGID_SBE, 1034 .version = FSI_VERSION_ANY, 1035 }, 1036 { 0 } 1037 }; 1038 1039 static struct fsi_driver sbefifo_drv = { 1040 .id_table = sbefifo_ids, 1041 .drv = { 1042 .name = DEVICE_NAME, 1043 .bus = &fsi_bus_type, 1044 .probe = sbefifo_probe, 1045 .remove = sbefifo_remove, 1046 } 1047 }; 1048 1049 static int sbefifo_init(void) 1050 { 1051 return fsi_driver_register(&sbefifo_drv); 1052 } 1053 1054 static void sbefifo_exit(void) 1055 { 1056 fsi_driver_unregister(&sbefifo_drv); 1057 } 1058 1059 module_init(sbefifo_init); 1060 module_exit(sbefifo_exit); 1061 MODULE_LICENSE("GPL"); 1062 MODULE_AUTHOR("Brad Bishop <bradleyb@fuzziesquirrel.com>"); 1063 MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>"); 1064 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); 1065 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 1066 MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine"); 1067