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/of.h> 13 #include <linux/poll.h> 14 #include <linux/proc_fs.h> 15 #include <linux/init.h> 16 #include <linux/vmalloc.h> 17 #include <linux/spinlock.h> 18 #include <linux/cpu.h> 19 #include <linux/workqueue.h> 20 #include <linux/slab.h> 21 #include <linux/topology.h> 22 23 #include <linux/uaccess.h> 24 #include <asm/io.h> 25 #include <asm/rtas.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 static void handle_rtas_event(const struct rtas_error_log *log) 277 { 278 if (!machine_is(pseries)) 279 return; 280 281 if (rtas_error_type(log) == RTAS_TYPE_PRRN) 282 pr_info_ratelimited("Platform resource reassignment ignored.\n"); 283 } 284 285 static int rtas_log_open(struct inode * inode, struct file * file) 286 { 287 return 0; 288 } 289 290 static int rtas_log_release(struct inode * inode, struct file * file) 291 { 292 return 0; 293 } 294 295 /* This will check if all events are logged, if they are then, we 296 * know that we can safely clear the events in NVRAM. 297 * Next we'll sit and wait for something else to log. 298 */ 299 static ssize_t rtas_log_read(struct file * file, char __user * buf, 300 size_t count, loff_t *ppos) 301 { 302 int error; 303 char *tmp; 304 unsigned long s; 305 unsigned long offset; 306 307 if (!buf || count < rtas_error_log_buffer_max) 308 return -EINVAL; 309 310 count = rtas_error_log_buffer_max; 311 312 if (!access_ok(buf, count)) 313 return -EFAULT; 314 315 tmp = kmalloc(count, GFP_KERNEL); 316 if (!tmp) 317 return -ENOMEM; 318 319 spin_lock_irqsave(&rtasd_log_lock, s); 320 321 /* if it's 0, then we know we got the last one (the one in NVRAM) */ 322 while (rtas_log_size == 0) { 323 if (file->f_flags & O_NONBLOCK) { 324 spin_unlock_irqrestore(&rtasd_log_lock, s); 325 error = -EAGAIN; 326 goto out; 327 } 328 329 if (!logging_enabled) { 330 spin_unlock_irqrestore(&rtasd_log_lock, s); 331 error = -ENODATA; 332 goto out; 333 } 334 #ifdef CONFIG_PPC64 335 nvram_clear_error_log(); 336 #endif /* CONFIG_PPC64 */ 337 338 spin_unlock_irqrestore(&rtasd_log_lock, s); 339 error = wait_event_interruptible(rtas_log_wait, rtas_log_size); 340 if (error) 341 goto out; 342 spin_lock_irqsave(&rtasd_log_lock, s); 343 } 344 345 offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK); 346 memcpy(tmp, &rtas_log_buf[offset], count); 347 348 rtas_log_start += 1; 349 rtas_log_size -= 1; 350 spin_unlock_irqrestore(&rtasd_log_lock, s); 351 352 error = copy_to_user(buf, tmp, count) ? -EFAULT : count; 353 out: 354 kfree(tmp); 355 return error; 356 } 357 358 static __poll_t rtas_log_poll(struct file *file, poll_table * wait) 359 { 360 poll_wait(file, &rtas_log_wait, wait); 361 if (rtas_log_size) 362 return EPOLLIN | EPOLLRDNORM; 363 return 0; 364 } 365 366 static const struct proc_ops rtas_log_proc_ops = { 367 .proc_read = rtas_log_read, 368 .proc_poll = rtas_log_poll, 369 .proc_open = rtas_log_open, 370 .proc_release = rtas_log_release, 371 .proc_lseek = noop_llseek, 372 }; 373 374 static int enable_surveillance(int timeout) 375 { 376 int error; 377 378 error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout); 379 380 if (error == 0) 381 return 0; 382 383 if (error == -EINVAL) { 384 printk(KERN_DEBUG "rtasd: surveillance not supported\n"); 385 return 0; 386 } 387 388 printk(KERN_ERR "rtasd: could not update surveillance\n"); 389 return -1; 390 } 391 392 static void do_event_scan(void) 393 { 394 int error; 395 do { 396 memset(logdata, 0, rtas_error_log_max); 397 error = rtas_call(event_scan, 4, 1, NULL, 398 RTAS_EVENT_SCAN_ALL_EVENTS, 0, 399 __pa(logdata), rtas_error_log_max); 400 if (error == -1) { 401 printk(KERN_ERR "event-scan failed\n"); 402 break; 403 } 404 405 if (error == 0) { 406 if (rtas_error_type((struct rtas_error_log *)logdata) != 407 RTAS_TYPE_PRRN) 408 pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 409 0); 410 handle_rtas_event((struct rtas_error_log *)logdata); 411 } 412 413 } while(error == 0); 414 } 415 416 static void rtas_event_scan(struct work_struct *w); 417 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan); 418 419 /* 420 * Delay should be at least one second since some machines have problems if 421 * we call event-scan too quickly. 422 */ 423 static unsigned long event_scan_delay = 1*HZ; 424 static int first_pass = 1; 425 426 static void rtas_event_scan(struct work_struct *w) 427 { 428 unsigned int cpu; 429 430 do_event_scan(); 431 432 cpus_read_lock(); 433 434 /* raw_ OK because just using CPU as starting point. */ 435 cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); 436 if (cpu >= nr_cpu_ids) { 437 cpu = cpumask_first(cpu_online_mask); 438 439 if (first_pass) { 440 first_pass = 0; 441 event_scan_delay = 30*HZ/rtas_event_scan_rate; 442 443 if (surveillance_timeout != -1) { 444 pr_debug("rtasd: enabling surveillance\n"); 445 enable_surveillance(surveillance_timeout); 446 pr_debug("rtasd: surveillance enabled\n"); 447 } 448 } 449 } 450 451 schedule_delayed_work_on(cpu, &event_scan_work, 452 __round_jiffies_relative(event_scan_delay, cpu)); 453 454 cpus_read_unlock(); 455 } 456 457 #ifdef CONFIG_PPC64 458 static void __init retrieve_nvram_error_log(void) 459 { 460 unsigned int err_type ; 461 int rc ; 462 463 /* See if we have any error stored in NVRAM */ 464 memset(logdata, 0, rtas_error_log_max); 465 rc = nvram_read_error_log(logdata, rtas_error_log_max, 466 &err_type, &error_log_cnt); 467 /* We can use rtas_log_buf now */ 468 logging_enabled = 1; 469 if (!rc) { 470 if (err_type != ERR_FLAG_ALREADY_LOGGED) { 471 pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0); 472 } 473 } 474 } 475 #else /* CONFIG_PPC64 */ 476 static void __init retrieve_nvram_error_log(void) 477 { 478 } 479 #endif /* CONFIG_PPC64 */ 480 481 static void __init start_event_scan(void) 482 { 483 printk(KERN_DEBUG "RTAS daemon started\n"); 484 pr_debug("rtasd: will sleep for %d milliseconds\n", 485 (30000 / rtas_event_scan_rate)); 486 487 /* Retrieve errors from nvram if any */ 488 retrieve_nvram_error_log(); 489 490 schedule_delayed_work_on(cpumask_first(cpu_online_mask), 491 &event_scan_work, event_scan_delay); 492 } 493 494 /* Cancel the rtas event scan work */ 495 void rtas_cancel_event_scan(void) 496 { 497 cancel_delayed_work_sync(&event_scan_work); 498 } 499 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan); 500 501 static int __init rtas_event_scan_init(void) 502 { 503 int err; 504 505 if (!machine_is(pseries) && !machine_is(chrp)) 506 return 0; 507 508 /* No RTAS */ 509 event_scan = rtas_function_token(RTAS_FN_EVENT_SCAN); 510 if (event_scan == RTAS_UNKNOWN_SERVICE) { 511 printk(KERN_INFO "rtasd: No event-scan on system\n"); 512 return -ENODEV; 513 } 514 515 err = of_property_read_u32(rtas.dev, "rtas-event-scan-rate", &rtas_event_scan_rate); 516 if (err) { 517 printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n"); 518 return -ENODEV; 519 } 520 521 if (!rtas_event_scan_rate) { 522 /* Broken firmware: take a rate of zero to mean don't scan */ 523 printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n"); 524 return 0; 525 } 526 527 /* Make room for the sequence number */ 528 rtas_error_log_max = rtas_get_error_log_max(); 529 rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int); 530 531 rtas_log_buf = vmalloc(array_size(LOG_NUMBER, 532 rtas_error_log_buffer_max)); 533 if (!rtas_log_buf) { 534 printk(KERN_ERR "rtasd: no memory\n"); 535 return -ENOMEM; 536 } 537 538 start_event_scan(); 539 540 return 0; 541 } 542 arch_initcall(rtas_event_scan_init); 543 544 static int __init rtas_init(void) 545 { 546 struct proc_dir_entry *entry; 547 548 if (!machine_is(pseries) && !machine_is(chrp)) 549 return 0; 550 551 if (!rtas_log_buf) 552 return -ENODEV; 553 554 entry = proc_create("powerpc/rtas/error_log", 0400, NULL, 555 &rtas_log_proc_ops); 556 if (!entry) 557 printk(KERN_ERR "Failed to create error_log proc entry\n"); 558 559 return 0; 560 } 561 __initcall(rtas_init); 562 563 static int __init surveillance_setup(char *str) 564 { 565 int i; 566 567 /* We only do surveillance on pseries */ 568 if (!machine_is(pseries)) 569 return 0; 570 571 if (get_option(&str,&i)) { 572 if (i >= 0 && i <= 255) 573 surveillance_timeout = i; 574 } 575 576 return 1; 577 } 578 __setup("surveillance=", surveillance_setup); 579 580 static int __init rtasmsgs_setup(char *str) 581 { 582 return (kstrtobool(str, &full_rtas_msgs) == 0); 583 } 584 __setup("rtasmsgs=", rtasmsgs_setup); 585