xref: /openbmc/linux/arch/powerpc/kernel/rtasd.c (revision 20e2fc42) 
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