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 case RTAS_TYPE_HVPIPE: 93 return "Hypervisor Pipe Notification event"; 94 } 95 96 return rtas_type[0]; 97 } 98 99 /* To see this info, grep RTAS /var/log/messages and each entry 100 * will be collected together with obvious begin/end. 101 * There will be a unique identifier on the begin and end lines. 102 * This will persist across reboots. 103 * 104 * format of error logs returned from RTAS: 105 * bytes (size) : contents 106 * -------------------------------------------------------- 107 * 0-7 (8) : rtas_error_log 108 * 8-47 (40) : extended info 109 * 48-51 (4) : vendor id 110 * 52-1023 (vendor specific) : location code and debug data 111 */ 112 static void printk_log_rtas(char *buf, int len) 113 { 114 115 int i,j,n = 0; 116 int perline = 16; 117 char buffer[64]; 118 char * str = "RTAS event"; 119 120 if (full_rtas_msgs) { 121 printk(RTAS_DEBUG "%d -------- %s begin --------\n", 122 error_log_cnt, str); 123 124 /* 125 * Print perline bytes on each line, each line will start 126 * with RTAS and a changing number, so syslogd will 127 * print lines that are otherwise the same. Separate every 128 * 4 bytes with a space. 129 */ 130 for (i = 0; i < len; i++) { 131 j = i % perline; 132 if (j == 0) { 133 memset(buffer, 0, sizeof(buffer)); 134 n = sprintf(buffer, "RTAS %d:", i/perline); 135 } 136 137 if ((i % 4) == 0) 138 n += sprintf(buffer+n, " "); 139 140 n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]); 141 142 if (j == (perline-1)) 143 printk(KERN_DEBUG "%s\n", buffer); 144 } 145 if ((i % perline) != 0) 146 printk(KERN_DEBUG "%s\n", buffer); 147 148 printk(RTAS_DEBUG "%d -------- %s end ----------\n", 149 error_log_cnt, str); 150 } else { 151 struct rtas_error_log *errlog = (struct rtas_error_log *)buf; 152 153 printk(RTAS_DEBUG "event: %d, Type: %s (%d), Severity: %d\n", 154 error_log_cnt, 155 rtas_event_type(rtas_error_type(errlog)), 156 rtas_error_type(errlog), 157 rtas_error_severity(errlog)); 158 } 159 } 160 161 static int log_rtas_len(char * buf) 162 { 163 int len; 164 struct rtas_error_log *err; 165 uint32_t extended_log_length; 166 167 /* rtas fixed header */ 168 len = 8; 169 err = (struct rtas_error_log *)buf; 170 extended_log_length = rtas_error_extended_log_length(err); 171 if (rtas_error_extended(err) && extended_log_length) { 172 173 /* extended header */ 174 len += extended_log_length; 175 } 176 177 if (rtas_error_log_max == 0) 178 rtas_error_log_max = rtas_get_error_log_max(); 179 180 if (len > rtas_error_log_max) 181 len = rtas_error_log_max; 182 183 return len; 184 } 185 186 /* 187 * First write to nvram, if fatal error, that is the only 188 * place we log the info. The error will be picked up 189 * on the next reboot by rtasd. If not fatal, run the 190 * method for the type of error. Currently, only RTAS 191 * errors have methods implemented, but in the future 192 * there might be a need to store data in nvram before a 193 * call to panic(). 194 * 195 * XXX We write to nvram periodically, to indicate error has 196 * been written and sync'd, but there is a possibility 197 * that if we don't shutdown correctly, a duplicate error 198 * record will be created on next reboot. 199 */ 200 void pSeries_log_error(char *buf, unsigned int err_type, int fatal) 201 { 202 unsigned long offset; 203 unsigned long s; 204 int len = 0; 205 206 pr_debug("rtasd: logging event\n"); 207 if (buf == NULL) 208 return; 209 210 spin_lock_irqsave(&rtasd_log_lock, s); 211 212 /* get length and increase count */ 213 switch (err_type & ERR_TYPE_MASK) { 214 case ERR_TYPE_RTAS_LOG: 215 len = log_rtas_len(buf); 216 if (!(err_type & ERR_FLAG_BOOT)) 217 error_log_cnt++; 218 break; 219 case ERR_TYPE_KERNEL_PANIC: 220 default: 221 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 222 spin_unlock_irqrestore(&rtasd_log_lock, s); 223 return; 224 } 225 226 #ifdef CONFIG_PPC64 227 /* Write error to NVRAM */ 228 if (logging_enabled && !(err_type & ERR_FLAG_BOOT)) 229 nvram_write_error_log(buf, len, err_type, error_log_cnt); 230 #endif /* CONFIG_PPC64 */ 231 232 /* 233 * rtas errors can occur during boot, and we do want to capture 234 * those somewhere, even if nvram isn't ready (why not?), and even 235 * if rtasd isn't ready. Put them into the boot log, at least. 236 */ 237 if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG) 238 printk_log_rtas(buf, len); 239 240 /* Check to see if we need to or have stopped logging */ 241 if (fatal || !logging_enabled) { 242 logging_enabled = 0; 243 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 244 spin_unlock_irqrestore(&rtasd_log_lock, s); 245 return; 246 } 247 248 /* call type specific method for error */ 249 switch (err_type & ERR_TYPE_MASK) { 250 case ERR_TYPE_RTAS_LOG: 251 offset = rtas_error_log_buffer_max * 252 ((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK); 253 254 /* First copy over sequence number */ 255 memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int)); 256 257 /* Second copy over error log data */ 258 offset += sizeof(int); 259 memcpy(&rtas_log_buf[offset], buf, len); 260 261 if (rtas_log_size < LOG_NUMBER) 262 rtas_log_size += 1; 263 else 264 rtas_log_start += 1; 265 266 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 267 spin_unlock_irqrestore(&rtasd_log_lock, s); 268 wake_up_interruptible(&rtas_log_wait); 269 break; 270 case ERR_TYPE_KERNEL_PANIC: 271 default: 272 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */ 273 spin_unlock_irqrestore(&rtasd_log_lock, s); 274 return; 275 } 276 } 277 278 static void handle_rtas_event(const struct rtas_error_log *log) 279 { 280 if (!machine_is(pseries)) 281 return; 282 283 if (rtas_error_type(log) == RTAS_TYPE_PRRN) 284 pr_info_ratelimited("Platform resource reassignment ignored.\n"); 285 } 286 287 static int rtas_log_open(struct inode * inode, struct file * file) 288 { 289 return 0; 290 } 291 292 static int rtas_log_release(struct inode * inode, struct file * file) 293 { 294 return 0; 295 } 296 297 /* This will check if all events are logged, if they are then, we 298 * know that we can safely clear the events in NVRAM. 299 * Next we'll sit and wait for something else to log. 300 */ 301 static ssize_t rtas_log_read(struct file * file, char __user * buf, 302 size_t count, loff_t *ppos) 303 { 304 int error; 305 char *tmp; 306 unsigned long s; 307 unsigned long offset; 308 309 if (!buf || count < rtas_error_log_buffer_max) 310 return -EINVAL; 311 312 count = rtas_error_log_buffer_max; 313 314 if (!access_ok(buf, count)) 315 return -EFAULT; 316 317 tmp = kmalloc(count, GFP_KERNEL); 318 if (!tmp) 319 return -ENOMEM; 320 321 spin_lock_irqsave(&rtasd_log_lock, s); 322 323 /* if it's 0, then we know we got the last one (the one in NVRAM) */ 324 while (rtas_log_size == 0) { 325 if (file->f_flags & O_NONBLOCK) { 326 spin_unlock_irqrestore(&rtasd_log_lock, s); 327 error = -EAGAIN; 328 goto out; 329 } 330 331 if (!logging_enabled) { 332 spin_unlock_irqrestore(&rtasd_log_lock, s); 333 error = -ENODATA; 334 goto out; 335 } 336 #ifdef CONFIG_PPC64 337 nvram_clear_error_log(); 338 #endif /* CONFIG_PPC64 */ 339 340 spin_unlock_irqrestore(&rtasd_log_lock, s); 341 error = wait_event_interruptible(rtas_log_wait, rtas_log_size); 342 if (error) 343 goto out; 344 spin_lock_irqsave(&rtasd_log_lock, s); 345 } 346 347 offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK); 348 memcpy(tmp, &rtas_log_buf[offset], count); 349 350 rtas_log_start += 1; 351 rtas_log_size -= 1; 352 spin_unlock_irqrestore(&rtasd_log_lock, s); 353 354 error = copy_to_user(buf, tmp, count) ? -EFAULT : count; 355 out: 356 kfree(tmp); 357 return error; 358 } 359 360 static __poll_t rtas_log_poll(struct file *file, poll_table * wait) 361 { 362 poll_wait(file, &rtas_log_wait, wait); 363 if (rtas_log_size) 364 return EPOLLIN | EPOLLRDNORM; 365 return 0; 366 } 367 368 static const struct proc_ops rtas_log_proc_ops = { 369 .proc_read = rtas_log_read, 370 .proc_poll = rtas_log_poll, 371 .proc_open = rtas_log_open, 372 .proc_release = rtas_log_release, 373 .proc_lseek = noop_llseek, 374 }; 375 376 static int enable_surveillance(int timeout) 377 { 378 int error; 379 380 error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout); 381 382 if (error == 0) 383 return 0; 384 385 if (error == -EINVAL) { 386 printk(KERN_DEBUG "rtasd: surveillance not supported\n"); 387 return 0; 388 } 389 390 printk(KERN_ERR "rtasd: could not update surveillance\n"); 391 return -1; 392 } 393 394 static void do_event_scan(void) 395 { 396 int error; 397 do { 398 memset(logdata, 0, rtas_error_log_max); 399 error = rtas_call(event_scan, 4, 1, NULL, 400 RTAS_EVENT_SCAN_ALL_EVENTS, 0, 401 __pa(logdata), rtas_error_log_max); 402 if (error == -1) { 403 printk(KERN_ERR "event-scan failed\n"); 404 break; 405 } 406 407 if (error == 0) { 408 if (rtas_error_type((struct rtas_error_log *)logdata) != 409 RTAS_TYPE_PRRN) 410 pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 411 0); 412 handle_rtas_event((struct rtas_error_log *)logdata); 413 } 414 415 } while(error == 0); 416 } 417 418 static void rtas_event_scan(struct work_struct *w); 419 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan); 420 421 /* 422 * Delay should be at least one second since some machines have problems if 423 * we call event-scan too quickly. 424 */ 425 static unsigned long event_scan_delay = 1*HZ; 426 static int first_pass = 1; 427 428 static void rtas_event_scan(struct work_struct *w) 429 { 430 unsigned int cpu; 431 432 do_event_scan(); 433 434 cpus_read_lock(); 435 436 /* raw_ OK because just using CPU as starting point. */ 437 cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); 438 if (cpu >= nr_cpu_ids) { 439 cpu = cpumask_first(cpu_online_mask); 440 441 if (first_pass) { 442 first_pass = 0; 443 event_scan_delay = 30*HZ/rtas_event_scan_rate; 444 445 if (surveillance_timeout != -1) { 446 pr_debug("rtasd: enabling surveillance\n"); 447 enable_surveillance(surveillance_timeout); 448 pr_debug("rtasd: surveillance enabled\n"); 449 } 450 } 451 } 452 453 schedule_delayed_work_on(cpu, &event_scan_work, 454 __round_jiffies_relative(event_scan_delay, cpu)); 455 456 cpus_read_unlock(); 457 } 458 459 #ifdef CONFIG_PPC64 460 static void __init retrieve_nvram_error_log(void) 461 { 462 unsigned int err_type ; 463 int rc ; 464 465 /* See if we have any error stored in NVRAM */ 466 memset(logdata, 0, rtas_error_log_max); 467 rc = nvram_read_error_log(logdata, rtas_error_log_max, 468 &err_type, &error_log_cnt); 469 /* We can use rtas_log_buf now */ 470 logging_enabled = 1; 471 if (!rc) { 472 if (err_type != ERR_FLAG_ALREADY_LOGGED) { 473 pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0); 474 } 475 } 476 } 477 #else /* CONFIG_PPC64 */ 478 static void __init retrieve_nvram_error_log(void) 479 { 480 } 481 #endif /* CONFIG_PPC64 */ 482 483 static void __init start_event_scan(void) 484 { 485 printk(KERN_DEBUG "RTAS daemon started\n"); 486 pr_debug("rtasd: will sleep for %d milliseconds\n", 487 (30000 / rtas_event_scan_rate)); 488 489 /* Retrieve errors from nvram if any */ 490 retrieve_nvram_error_log(); 491 492 schedule_delayed_work_on(cpumask_first(cpu_online_mask), 493 &event_scan_work, event_scan_delay); 494 } 495 496 /* Cancel the rtas event scan work */ 497 void rtas_cancel_event_scan(void) 498 { 499 cancel_delayed_work_sync(&event_scan_work); 500 } 501 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan); 502 503 static int __init rtas_event_scan_init(void) 504 { 505 int err; 506 507 if (!machine_is(pseries) && !machine_is(chrp)) 508 return 0; 509 510 /* No RTAS */ 511 event_scan = rtas_function_token(RTAS_FN_EVENT_SCAN); 512 if (event_scan == RTAS_UNKNOWN_SERVICE) { 513 printk(KERN_INFO "rtasd: No event-scan on system\n"); 514 return -ENODEV; 515 } 516 517 err = of_property_read_u32(rtas.dev, "rtas-event-scan-rate", &rtas_event_scan_rate); 518 if (err) { 519 printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n"); 520 return -ENODEV; 521 } 522 523 if (!rtas_event_scan_rate) { 524 /* Broken firmware: take a rate of zero to mean don't scan */ 525 printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n"); 526 return 0; 527 } 528 529 /* Make room for the sequence number */ 530 rtas_error_log_max = rtas_get_error_log_max(); 531 rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int); 532 533 rtas_log_buf = vmalloc(array_size(LOG_NUMBER, 534 rtas_error_log_buffer_max)); 535 if (!rtas_log_buf) { 536 printk(KERN_ERR "rtasd: no memory\n"); 537 return -ENOMEM; 538 } 539 540 start_event_scan(); 541 542 return 0; 543 } 544 arch_initcall(rtas_event_scan_init); 545 546 static int __init rtas_init(void) 547 { 548 struct proc_dir_entry *entry; 549 550 if (!machine_is(pseries) && !machine_is(chrp)) 551 return 0; 552 553 if (!rtas_log_buf) 554 return -ENODEV; 555 556 entry = proc_create("powerpc/rtas/error_log", 0400, NULL, 557 &rtas_log_proc_ops); 558 if (!entry) 559 printk(KERN_ERR "Failed to create error_log proc entry\n"); 560 561 return 0; 562 } 563 __initcall(rtas_init); 564 565 static int __init surveillance_setup(char *str) 566 { 567 int i; 568 569 /* We only do surveillance on pseries */ 570 if (!machine_is(pseries)) 571 return 0; 572 573 if (get_option(&str,&i)) { 574 if (i >= 0 && i <= 255) 575 surveillance_timeout = i; 576 } 577 578 return 1; 579 } 580 __setup("surveillance=", surveillance_setup); 581 582 static int __init rtasmsgs_setup(char *str) 583 { 584 return (kstrtobool(str, &full_rtas_msgs) == 0); 585 } 586 __setup("rtasmsgs=", rtasmsgs_setup); 587