1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM 4 * 5 * Communication to userspace based on kernel/printk.c 6 */ 7 8 #include <linux/types.h> 9 #include <linux/errno.h> 10 #include <linux/sched.h> 11 #include <linux/kernel.h> 12 #include <linux/poll.h> 13 #include <linux/proc_fs.h> 14 #include <linux/init.h> 15 #include <linux/vmalloc.h> 16 #include <linux/spinlock.h> 17 #include <linux/cpu.h> 18 #include <linux/workqueue.h> 19 #include <linux/slab.h> 20 #include <linux/topology.h> 21 22 #include <linux/uaccess.h> 23 #include <asm/io.h> 24 #include <asm/rtas.h> 25 #include <asm/prom.h> 26 #include <asm/nvram.h> 27 #include <linux/atomic.h> 28 #include <asm/machdep.h> 29 #include <asm/topology.h> 30 31 32 static DEFINE_SPINLOCK(rtasd_log_lock); 33 34 static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait); 35 36 static char *rtas_log_buf; 37 static unsigned long rtas_log_start; 38 static unsigned long rtas_log_size; 39 40 static int surveillance_timeout = -1; 41 42 static unsigned int rtas_error_log_max; 43 static unsigned int rtas_error_log_buffer_max; 44 45 /* RTAS service tokens */ 46 static unsigned int event_scan; 47 static unsigned int rtas_event_scan_rate; 48 49 static bool full_rtas_msgs; 50 51 /* Stop logging to nvram after first fatal error */ 52 static int logging_enabled; /* Until we initialize everything, 53 * make sure we don't try logging 54 * anything */ 55 static int error_log_cnt; 56 57 /* 58 * Since we use 32 bit RTAS, the physical address of this must be below 59 * 4G or else bad things happen. Allocate this in the kernel data and 60 * make it big enough. 61 */ 62 static unsigned char logdata[RTAS_ERROR_LOG_MAX]; 63 64 static char *rtas_type[] = { 65 "Unknown", "Retry", "TCE Error", "Internal Device Failure", 66 "Timeout", "Data Parity", "Address Parity", "Cache Parity", 67 "Address Invalid", "ECC Uncorrected", "ECC Corrupted", 68 }; 69 70 static char *rtas_event_type(int type) 71 { 72 if ((type > 0) && (type < 11)) 73 return rtas_type[type]; 74 75 switch (type) { 76 case RTAS_TYPE_EPOW: 77 return "EPOW"; 78 case RTAS_TYPE_PLATFORM: 79 return "Platform Error"; 80 case RTAS_TYPE_IO: 81 return "I/O Event"; 82 case RTAS_TYPE_INFO: 83 return "Platform Information Event"; 84 case RTAS_TYPE_DEALLOC: 85 return "Resource Deallocation Event"; 86 case RTAS_TYPE_DUMP: 87 return "Dump Notification Event"; 88 case RTAS_TYPE_PRRN: 89 return "Platform Resource Reassignment Event"; 90 case RTAS_TYPE_HOTPLUG: 91 return "Hotplug Event"; 92 } 93 94 return rtas_type[0]; 95 } 96 97 /* To see this info, grep RTAS /var/log/messages and each entry 98 * will be collected together with obvious begin/end. 99 * There will be a unique identifier on the begin and end lines. 100 * This will persist across reboots. 101 * 102 * format of error logs returned from RTAS: 103 * bytes (size) : contents 104 * -------------------------------------------------------- 105 * 0-7 (8) : rtas_error_log 106 * 8-47 (40) : extended info 107 * 48-51 (4) : vendor id 108 * 52-1023 (vendor specific) : location code and debug data 109 */ 110 static void printk_log_rtas(char *buf, int len) 111 { 112 113 int i,j,n = 0; 114 int perline = 16; 115 char buffer[64]; 116 char * str = "RTAS event"; 117 118 if (full_rtas_msgs) { 119 printk(RTAS_DEBUG "%d -------- %s begin --------\n", 120 error_log_cnt, str); 121 122 /* 123 * Print perline bytes on each line, each line will start 124 * with RTAS and a changing number, so syslogd will 125 * print lines that are otherwise the same. Separate every 126 * 4 bytes with a space. 127 */ 128 for (i = 0; i < len; i++) { 129 j = i % perline; 130 if (j == 0) { 131 memset(buffer, 0, sizeof(buffer)); 132 n = sprintf(buffer, "RTAS %d:", i/perline); 133 } 134 135 if ((i % 4) == 0) 136 n += sprintf(buffer+n, " "); 137 138 n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]); 139 140 if (j == (perline-1)) 141 printk(KERN_DEBUG "%s\n", buffer); 142 } 143 if ((i % perline) != 0) 144 printk(KERN_DEBUG "%s\n", buffer); 145 146 printk(RTAS_DEBUG "%d -------- %s end ----------\n", 147 error_log_cnt, str); 148 } else { 149 struct rtas_error_log *errlog = (struct rtas_error_log *)buf; 150 151 printk(RTAS_DEBUG "event: %d, Type: %s (%d), Severity: %d\n", 152 error_log_cnt, 153 rtas_event_type(rtas_error_type(errlog)), 154 rtas_error_type(errlog), 155 rtas_error_severity(errlog)); 156 } 157 } 158 159 static int log_rtas_len(char * buf) 160 { 161 int len; 162 struct rtas_error_log *err; 163 uint32_t extended_log_length; 164 165 /* rtas fixed header */ 166 len = 8; 167 err = (struct rtas_error_log *)buf; 168 extended_log_length = rtas_error_extended_log_length(err); 169 if (rtas_error_extended(err) && extended_log_length) { 170 171 /* extended header */ 172 len += extended_log_length; 173 } 174 175 if (rtas_error_log_max == 0) 176 rtas_error_log_max = rtas_get_error_log_max(); 177 178 if (len > rtas_error_log_max) 179 len = rtas_error_log_max; 180 181 return len; 182 } 183 184 /* 185 * First write to nvram, if fatal error, that is the only 186 * place we log the info. The error will be picked up 187 * on the next reboot by rtasd. If not fatal, run the 188 * method for the type of error. Currently, only RTAS 189 * errors have methods implemented, but in the future 190 * there might be a need to store data in nvram before a 191 * call to panic(). 192 * 193 * XXX We write to nvram periodically, to indicate error has 194 * been written and sync'd, but there is a possibility 195 * that if we don't shutdown correctly, a duplicate error 196 * record will be created on next reboot. 197 */ 198 void pSeries_log_error(char *buf, unsigned int err_type, int fatal) 199 { 200 unsigned long offset; 201 unsigned long s; 202 int len = 0; 203 204 pr_debug("rtasd: logging event\n"); 205 if (buf == NULL) 206 return; 207 208 spin_lock_irqsave(&rtasd_log_lock, s); 209 210 /* get length and increase count */ 211 switch (err_type & ERR_TYPE_MASK) { 212 case ERR_TYPE_RTAS_LOG: 213 len = log_rtas_len(buf); 214 if (!(err_type & ERR_FLAG_BOOT)) 215 error_log_cnt++; 216 break; 217 case ERR_TYPE_KERNEL_PANIC: 218 default: 219 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 220 spin_unlock_irqrestore(&rtasd_log_lock, s); 221 return; 222 } 223 224 #ifdef CONFIG_PPC64 225 /* Write error to NVRAM */ 226 if (logging_enabled && !(err_type & ERR_FLAG_BOOT)) 227 nvram_write_error_log(buf, len, err_type, error_log_cnt); 228 #endif /* CONFIG_PPC64 */ 229 230 /* 231 * rtas errors can occur during boot, and we do want to capture 232 * those somewhere, even if nvram isn't ready (why not?), and even 233 * if rtasd isn't ready. Put them into the boot log, at least. 234 */ 235 if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG) 236 printk_log_rtas(buf, len); 237 238 /* Check to see if we need to or have stopped logging */ 239 if (fatal || !logging_enabled) { 240 logging_enabled = 0; 241 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 242 spin_unlock_irqrestore(&rtasd_log_lock, s); 243 return; 244 } 245 246 /* call type specific method for error */ 247 switch (err_type & ERR_TYPE_MASK) { 248 case ERR_TYPE_RTAS_LOG: 249 offset = rtas_error_log_buffer_max * 250 ((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK); 251 252 /* First copy over sequence number */ 253 memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int)); 254 255 /* Second copy over error log data */ 256 offset += sizeof(int); 257 memcpy(&rtas_log_buf[offset], buf, len); 258 259 if (rtas_log_size < LOG_NUMBER) 260 rtas_log_size += 1; 261 else 262 rtas_log_start += 1; 263 264 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 265 spin_unlock_irqrestore(&rtasd_log_lock, s); 266 wake_up_interruptible(&rtas_log_wait); 267 break; 268 case ERR_TYPE_KERNEL_PANIC: 269 default: 270 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 271 spin_unlock_irqrestore(&rtasd_log_lock, s); 272 return; 273 } 274 } 275 276 #ifdef CONFIG_PPC_PSERIES 277 static void handle_prrn_event(s32 scope) 278 { 279 /* 280 * For PRRN, we must pass the negative of the scope value in 281 * the RTAS event. 282 */ 283 pseries_devicetree_update(-scope); 284 numa_update_cpu_topology(false); 285 } 286 287 static void handle_rtas_event(const struct rtas_error_log *log) 288 { 289 if (rtas_error_type(log) != RTAS_TYPE_PRRN || !prrn_is_enabled()) 290 return; 291 292 /* For PRRN Events the extended log length is used to denote 293 * the scope for calling rtas update-nodes. 294 */ 295 handle_prrn_event(rtas_error_extended_log_length(log)); 296 } 297 298 #else 299 300 static void handle_rtas_event(const struct rtas_error_log *log) 301 { 302 return; 303 } 304 305 #endif 306 307 static int rtas_log_open(struct inode * inode, struct file * file) 308 { 309 return 0; 310 } 311 312 static int rtas_log_release(struct inode * inode, struct file * file) 313 { 314 return 0; 315 } 316 317 /* This will check if all events are logged, if they are then, we 318 * know that we can safely clear the events in NVRAM. 319 * Next we'll sit and wait for something else to log. 320 */ 321 static ssize_t rtas_log_read(struct file * file, char __user * buf, 322 size_t count, loff_t *ppos) 323 { 324 int error; 325 char *tmp; 326 unsigned long s; 327 unsigned long offset; 328 329 if (!buf || count < rtas_error_log_buffer_max) 330 return -EINVAL; 331 332 count = rtas_error_log_buffer_max; 333 334 if (!access_ok(buf, count)) 335 return -EFAULT; 336 337 tmp = kmalloc(count, GFP_KERNEL); 338 if (!tmp) 339 return -ENOMEM; 340 341 spin_lock_irqsave(&rtasd_log_lock, s); 342 343 /* if it's 0, then we know we got the last one (the one in NVRAM) */ 344 while (rtas_log_size == 0) { 345 if (file->f_flags & O_NONBLOCK) { 346 spin_unlock_irqrestore(&rtasd_log_lock, s); 347 error = -EAGAIN; 348 goto out; 349 } 350 351 if (!logging_enabled) { 352 spin_unlock_irqrestore(&rtasd_log_lock, s); 353 error = -ENODATA; 354 goto out; 355 } 356 #ifdef CONFIG_PPC64 357 nvram_clear_error_log(); 358 #endif /* CONFIG_PPC64 */ 359 360 spin_unlock_irqrestore(&rtasd_log_lock, s); 361 error = wait_event_interruptible(rtas_log_wait, rtas_log_size); 362 if (error) 363 goto out; 364 spin_lock_irqsave(&rtasd_log_lock, s); 365 } 366 367 offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK); 368 memcpy(tmp, &rtas_log_buf[offset], count); 369 370 rtas_log_start += 1; 371 rtas_log_size -= 1; 372 spin_unlock_irqrestore(&rtasd_log_lock, s); 373 374 error = copy_to_user(buf, tmp, count) ? -EFAULT : count; 375 out: 376 kfree(tmp); 377 return error; 378 } 379 380 static __poll_t rtas_log_poll(struct file *file, poll_table * wait) 381 { 382 poll_wait(file, &rtas_log_wait, wait); 383 if (rtas_log_size) 384 return EPOLLIN | EPOLLRDNORM; 385 return 0; 386 } 387 388 static const struct file_operations proc_rtas_log_operations = { 389 .read = rtas_log_read, 390 .poll = rtas_log_poll, 391 .open = rtas_log_open, 392 .release = rtas_log_release, 393 .llseek = noop_llseek, 394 }; 395 396 static int enable_surveillance(int timeout) 397 { 398 int error; 399 400 error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout); 401 402 if (error == 0) 403 return 0; 404 405 if (error == -EINVAL) { 406 printk(KERN_DEBUG "rtasd: surveillance not supported\n"); 407 return 0; 408 } 409 410 printk(KERN_ERR "rtasd: could not update surveillance\n"); 411 return -1; 412 } 413 414 static void do_event_scan(void) 415 { 416 int error; 417 do { 418 memset(logdata, 0, rtas_error_log_max); 419 error = rtas_call(event_scan, 4, 1, NULL, 420 RTAS_EVENT_SCAN_ALL_EVENTS, 0, 421 __pa(logdata), rtas_error_log_max); 422 if (error == -1) { 423 printk(KERN_ERR "event-scan failed\n"); 424 break; 425 } 426 427 if (error == 0) { 428 if (rtas_error_type((struct rtas_error_log *)logdata) != 429 RTAS_TYPE_PRRN) 430 pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 431 0); 432 handle_rtas_event((struct rtas_error_log *)logdata); 433 } 434 435 } while(error == 0); 436 } 437 438 static void rtas_event_scan(struct work_struct *w); 439 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan); 440 441 /* 442 * Delay should be at least one second since some machines have problems if 443 * we call event-scan too quickly. 444 */ 445 static unsigned long event_scan_delay = 1*HZ; 446 static int first_pass = 1; 447 448 static void rtas_event_scan(struct work_struct *w) 449 { 450 unsigned int cpu; 451 452 do_event_scan(); 453 454 get_online_cpus(); 455 456 /* raw_ OK because just using CPU as starting point. */ 457 cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); 458 if (cpu >= nr_cpu_ids) { 459 cpu = cpumask_first(cpu_online_mask); 460 461 if (first_pass) { 462 first_pass = 0; 463 event_scan_delay = 30*HZ/rtas_event_scan_rate; 464 465 if (surveillance_timeout != -1) { 466 pr_debug("rtasd: enabling surveillance\n"); 467 enable_surveillance(surveillance_timeout); 468 pr_debug("rtasd: surveillance enabled\n"); 469 } 470 } 471 } 472 473 schedule_delayed_work_on(cpu, &event_scan_work, 474 __round_jiffies_relative(event_scan_delay, cpu)); 475 476 put_online_cpus(); 477 } 478 479 #ifdef CONFIG_PPC64 480 static void retrieve_nvram_error_log(void) 481 { 482 unsigned int err_type ; 483 int rc ; 484 485 /* See if we have any error stored in NVRAM */ 486 memset(logdata, 0, rtas_error_log_max); 487 rc = nvram_read_error_log(logdata, rtas_error_log_max, 488 &err_type, &error_log_cnt); 489 /* We can use rtas_log_buf now */ 490 logging_enabled = 1; 491 if (!rc) { 492 if (err_type != ERR_FLAG_ALREADY_LOGGED) { 493 pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0); 494 } 495 } 496 } 497 #else /* CONFIG_PPC64 */ 498 static void retrieve_nvram_error_log(void) 499 { 500 } 501 #endif /* CONFIG_PPC64 */ 502 503 static void start_event_scan(void) 504 { 505 printk(KERN_DEBUG "RTAS daemon started\n"); 506 pr_debug("rtasd: will sleep for %d milliseconds\n", 507 (30000 / rtas_event_scan_rate)); 508 509 /* Retrieve errors from nvram if any */ 510 retrieve_nvram_error_log(); 511 512 schedule_delayed_work_on(cpumask_first(cpu_online_mask), 513 &event_scan_work, event_scan_delay); 514 } 515 516 /* Cancel the rtas event scan work */ 517 void rtas_cancel_event_scan(void) 518 { 519 cancel_delayed_work_sync(&event_scan_work); 520 } 521 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan); 522 523 static int __init rtas_event_scan_init(void) 524 { 525 if (!machine_is(pseries) && !machine_is(chrp)) 526 return 0; 527 528 /* No RTAS */ 529 event_scan = rtas_token("event-scan"); 530 if (event_scan == RTAS_UNKNOWN_SERVICE) { 531 printk(KERN_INFO "rtasd: No event-scan on system\n"); 532 return -ENODEV; 533 } 534 535 rtas_event_scan_rate = rtas_token("rtas-event-scan-rate"); 536 if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) { 537 printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n"); 538 return -ENODEV; 539 } 540 541 if (!rtas_event_scan_rate) { 542 /* Broken firmware: take a rate of zero to mean don't scan */ 543 printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n"); 544 return 0; 545 } 546 547 /* Make room for the sequence number */ 548 rtas_error_log_max = rtas_get_error_log_max(); 549 rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int); 550 551 rtas_log_buf = vmalloc(array_size(LOG_NUMBER, 552 rtas_error_log_buffer_max)); 553 if (!rtas_log_buf) { 554 printk(KERN_ERR "rtasd: no memory\n"); 555 return -ENOMEM; 556 } 557 558 start_event_scan(); 559 560 return 0; 561 } 562 arch_initcall(rtas_event_scan_init); 563 564 static int __init rtas_init(void) 565 { 566 struct proc_dir_entry *entry; 567 568 if (!machine_is(pseries) && !machine_is(chrp)) 569 return 0; 570 571 if (!rtas_log_buf) 572 return -ENODEV; 573 574 entry = proc_create("powerpc/rtas/error_log", 0400, NULL, 575 &proc_rtas_log_operations); 576 if (!entry) 577 printk(KERN_ERR "Failed to create error_log proc entry\n"); 578 579 return 0; 580 } 581 __initcall(rtas_init); 582 583 static int __init surveillance_setup(char *str) 584 { 585 int i; 586 587 /* We only do surveillance on pseries */ 588 if (!machine_is(pseries)) 589 return 0; 590 591 if (get_option(&str,&i)) { 592 if (i >= 0 && i <= 255) 593 surveillance_timeout = i; 594 } 595 596 return 1; 597 } 598 __setup("surveillance=", surveillance_setup); 599 600 static int __init rtasmsgs_setup(char *str) 601 { 602 return (kstrtobool(str, &full_rtas_msgs) == 0); 603 } 604 __setup("rtasmsgs=", rtasmsgs_setup); 605