xref: /openbmc/linux/arch/powerpc/kernel/rtasd.c (revision 8730046c) 
1 /*
2  * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  *
9  * Communication to userspace based on kernel/printk.c
10  */
11 
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/poll.h>
17 #include <linux/proc_fs.h>
18 #include <linux/init.h>
19 #include <linux/vmalloc.h>
20 #include <linux/spinlock.h>
21 #include <linux/cpu.h>
22 #include <linux/workqueue.h>
23 #include <linux/slab.h>
24 
25 #include <linux/uaccess.h>
26 #include <asm/io.h>
27 #include <asm/rtas.h>
28 #include <asm/prom.h>
29 #include <asm/nvram.h>
30 #include <linux/atomic.h>
31 #include <asm/machdep.h>
32 #include <asm/topology.h>
33 
34 
35 static DEFINE_SPINLOCK(rtasd_log_lock);
36 
37 static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
38 
39 static char *rtas_log_buf;
40 static unsigned long rtas_log_start;
41 static unsigned long rtas_log_size;
42 
43 static int surveillance_timeout = -1;
44 
45 static unsigned int rtas_error_log_max;
46 static unsigned int rtas_error_log_buffer_max;
47 
48 /* RTAS service tokens */
49 static unsigned int event_scan;
50 static unsigned int rtas_event_scan_rate;
51 
52 static bool full_rtas_msgs;
53 
54 /* Stop logging to nvram after first fatal error */
55 static int logging_enabled; /* Until we initialize everything,
56                              * make sure we don't try logging
57                              * anything */
58 static int error_log_cnt;
59 
60 /*
61  * Since we use 32 bit RTAS, the physical address of this must be below
62  * 4G or else bad things happen. Allocate this in the kernel data and
63  * make it big enough.
64  */
65 static unsigned char logdata[RTAS_ERROR_LOG_MAX];
66 
67 static char *rtas_type[] = {
68 	"Unknown", "Retry", "TCE Error", "Internal Device Failure",
69 	"Timeout", "Data Parity", "Address Parity", "Cache Parity",
70 	"Address Invalid", "ECC Uncorrected", "ECC Corrupted",
71 };
72 
73 static char *rtas_event_type(int type)
74 {
75 	if ((type > 0) && (type < 11))
76 		return rtas_type[type];
77 
78 	switch (type) {
79 		case RTAS_TYPE_EPOW:
80 			return "EPOW";
81 		case RTAS_TYPE_PLATFORM:
82 			return "Platform Error";
83 		case RTAS_TYPE_IO:
84 			return "I/O Event";
85 		case RTAS_TYPE_INFO:
86 			return "Platform Information Event";
87 		case RTAS_TYPE_DEALLOC:
88 			return "Resource Deallocation Event";
89 		case RTAS_TYPE_DUMP:
90 			return "Dump Notification Event";
91 		case RTAS_TYPE_PRRN:
92 			return "Platform Resource Reassignment Event";
93 	}
94 
95 	return rtas_type[0];
96 }
97 
98 /* To see this info, grep RTAS /var/log/messages and each entry
99  * will be collected together with obvious begin/end.
100  * There will be a unique identifier on the begin and end lines.
101  * This will persist across reboots.
102  *
103  * format of error logs returned from RTAS:
104  * bytes	(size)	: contents
105  * --------------------------------------------------------
106  * 0-7		(8)	: rtas_error_log
107  * 8-47		(40)	: extended info
108  * 48-51	(4)	: vendor id
109  * 52-1023 (vendor specific) : location code and debug data
110  */
111 static void printk_log_rtas(char *buf, int len)
112 {
113 
114 	int i,j,n = 0;
115 	int perline = 16;
116 	char buffer[64];
117 	char * str = "RTAS event";
118 
119 	if (full_rtas_msgs) {
120 		printk(RTAS_DEBUG "%d -------- %s begin --------\n",
121 		       error_log_cnt, str);
122 
123 		/*
124 		 * Print perline bytes on each line, each line will start
125 		 * with RTAS and a changing number, so syslogd will
126 		 * print lines that are otherwise the same.  Separate every
127 		 * 4 bytes with a space.
128 		 */
129 		for (i = 0; i < len; i++) {
130 			j = i % perline;
131 			if (j == 0) {
132 				memset(buffer, 0, sizeof(buffer));
133 				n = sprintf(buffer, "RTAS %d:", i/perline);
134 			}
135 
136 			if ((i % 4) == 0)
137 				n += sprintf(buffer+n, " ");
138 
139 			n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]);
140 
141 			if (j == (perline-1))
142 				printk(KERN_DEBUG "%s\n", buffer);
143 		}
144 		if ((i % perline) != 0)
145 			printk(KERN_DEBUG "%s\n", buffer);
146 
147 		printk(RTAS_DEBUG "%d -------- %s end ----------\n",
148 		       error_log_cnt, str);
149 	} else {
150 		struct rtas_error_log *errlog = (struct rtas_error_log *)buf;
151 
152 		printk(RTAS_DEBUG "event: %d, Type: %s, Severity: %d\n",
153 		       error_log_cnt, rtas_event_type(rtas_error_type(errlog)),
154 		       rtas_error_severity(errlog));
155 	}
156 }
157 
158 static int log_rtas_len(char * buf)
159 {
160 	int len;
161 	struct rtas_error_log *err;
162 	uint32_t extended_log_length;
163 
164 	/* rtas fixed header */
165 	len = 8;
166 	err = (struct rtas_error_log *)buf;
167 	extended_log_length = rtas_error_extended_log_length(err);
168 	if (rtas_error_extended(err) && extended_log_length) {
169 
170 		/* extended header */
171 		len += extended_log_length;
172 	}
173 
174 	if (rtas_error_log_max == 0)
175 		rtas_error_log_max = rtas_get_error_log_max();
176 
177 	if (len > rtas_error_log_max)
178 		len = rtas_error_log_max;
179 
180 	return len;
181 }
182 
183 /*
184  * First write to nvram, if fatal error, that is the only
185  * place we log the info.  The error will be picked up
186  * on the next reboot by rtasd.  If not fatal, run the
187  * method for the type of error.  Currently, only RTAS
188  * errors have methods implemented, but in the future
189  * there might be a need to store data in nvram before a
190  * call to panic().
191  *
192  * XXX We write to nvram periodically, to indicate error has
193  * been written and sync'd, but there is a possibility
194  * that if we don't shutdown correctly, a duplicate error
195  * record will be created on next reboot.
196  */
197 void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
198 {
199 	unsigned long offset;
200 	unsigned long s;
201 	int len = 0;
202 
203 	pr_debug("rtasd: logging event\n");
204 	if (buf == NULL)
205 		return;
206 
207 	spin_lock_irqsave(&rtasd_log_lock, s);
208 
209 	/* get length and increase count */
210 	switch (err_type & ERR_TYPE_MASK) {
211 	case ERR_TYPE_RTAS_LOG:
212 		len = log_rtas_len(buf);
213 		if (!(err_type & ERR_FLAG_BOOT))
214 			error_log_cnt++;
215 		break;
216 	case ERR_TYPE_KERNEL_PANIC:
217 	default:
218 		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
219 		spin_unlock_irqrestore(&rtasd_log_lock, s);
220 		return;
221 	}
222 
223 #ifdef CONFIG_PPC64
224 	/* Write error to NVRAM */
225 	if (logging_enabled && !(err_type & ERR_FLAG_BOOT))
226 		nvram_write_error_log(buf, len, err_type, error_log_cnt);
227 #endif /* CONFIG_PPC64 */
228 
229 	/*
230 	 * rtas errors can occur during boot, and we do want to capture
231 	 * those somewhere, even if nvram isn't ready (why not?), and even
232 	 * if rtasd isn't ready. Put them into the boot log, at least.
233 	 */
234 	if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG)
235 		printk_log_rtas(buf, len);
236 
237 	/* Check to see if we need to or have stopped logging */
238 	if (fatal || !logging_enabled) {
239 		logging_enabled = 0;
240 		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
241 		spin_unlock_irqrestore(&rtasd_log_lock, s);
242 		return;
243 	}
244 
245 	/* call type specific method for error */
246 	switch (err_type & ERR_TYPE_MASK) {
247 	case ERR_TYPE_RTAS_LOG:
248 		offset = rtas_error_log_buffer_max *
249 			((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK);
250 
251 		/* First copy over sequence number */
252 		memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int));
253 
254 		/* Second copy over error log data */
255 		offset += sizeof(int);
256 		memcpy(&rtas_log_buf[offset], buf, len);
257 
258 		if (rtas_log_size < LOG_NUMBER)
259 			rtas_log_size += 1;
260 		else
261 			rtas_log_start += 1;
262 
263 		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
264 		spin_unlock_irqrestore(&rtasd_log_lock, s);
265 		wake_up_interruptible(&rtas_log_wait);
266 		break;
267 	case ERR_TYPE_KERNEL_PANIC:
268 	default:
269 		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
270 		spin_unlock_irqrestore(&rtasd_log_lock, s);
271 		return;
272 	}
273 }
274 
275 #ifdef CONFIG_PPC_PSERIES
276 static s32 prrn_update_scope;
277 
278 static void prrn_work_fn(struct work_struct *work)
279 {
280 	/*
281 	 * For PRRN, we must pass the negative of the scope value in
282 	 * the RTAS event.
283 	 */
284 	pseries_devicetree_update(-prrn_update_scope);
285 }
286 
287 static DECLARE_WORK(prrn_work, prrn_work_fn);
288 
289 static void prrn_schedule_update(u32 scope)
290 {
291 	flush_work(&prrn_work);
292 	prrn_update_scope = scope;
293 	schedule_work(&prrn_work);
294 }
295 
296 static void handle_rtas_event(const struct rtas_error_log *log)
297 {
298 	if (rtas_error_type(log) != RTAS_TYPE_PRRN || !prrn_is_enabled())
299 		return;
300 
301 	/* For PRRN Events the extended log length is used to denote
302 	 * the scope for calling rtas update-nodes.
303 	 */
304 	prrn_schedule_update(rtas_error_extended_log_length(log));
305 }
306 
307 #else
308 
309 static void handle_rtas_event(const struct rtas_error_log *log)
310 {
311 	return;
312 }
313 
314 #endif
315 
316 static int rtas_log_open(struct inode * inode, struct file * file)
317 {
318 	return 0;
319 }
320 
321 static int rtas_log_release(struct inode * inode, struct file * file)
322 {
323 	return 0;
324 }
325 
326 /* This will check if all events are logged, if they are then, we
327  * know that we can safely clear the events in NVRAM.
328  * Next we'll sit and wait for something else to log.
329  */
330 static ssize_t rtas_log_read(struct file * file, char __user * buf,
331 			 size_t count, loff_t *ppos)
332 {
333 	int error;
334 	char *tmp;
335 	unsigned long s;
336 	unsigned long offset;
337 
338 	if (!buf || count < rtas_error_log_buffer_max)
339 		return -EINVAL;
340 
341 	count = rtas_error_log_buffer_max;
342 
343 	if (!access_ok(VERIFY_WRITE, buf, count))
344 		return -EFAULT;
345 
346 	tmp = kmalloc(count, GFP_KERNEL);
347 	if (!tmp)
348 		return -ENOMEM;
349 
350 	spin_lock_irqsave(&rtasd_log_lock, s);
351 
352 	/* if it's 0, then we know we got the last one (the one in NVRAM) */
353 	while (rtas_log_size == 0) {
354 		if (file->f_flags & O_NONBLOCK) {
355 			spin_unlock_irqrestore(&rtasd_log_lock, s);
356 			error = -EAGAIN;
357 			goto out;
358 		}
359 
360 		if (!logging_enabled) {
361 			spin_unlock_irqrestore(&rtasd_log_lock, s);
362 			error = -ENODATA;
363 			goto out;
364 		}
365 #ifdef CONFIG_PPC64
366 		nvram_clear_error_log();
367 #endif /* CONFIG_PPC64 */
368 
369 		spin_unlock_irqrestore(&rtasd_log_lock, s);
370 		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
371 		if (error)
372 			goto out;
373 		spin_lock_irqsave(&rtasd_log_lock, s);
374 	}
375 
376 	offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
377 	memcpy(tmp, &rtas_log_buf[offset], count);
378 
379 	rtas_log_start += 1;
380 	rtas_log_size -= 1;
381 	spin_unlock_irqrestore(&rtasd_log_lock, s);
382 
383 	error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
384 out:
385 	kfree(tmp);
386 	return error;
387 }
388 
389 static unsigned int rtas_log_poll(struct file *file, poll_table * wait)
390 {
391 	poll_wait(file, &rtas_log_wait, wait);
392 	if (rtas_log_size)
393 		return POLLIN | POLLRDNORM;
394 	return 0;
395 }
396 
397 static const struct file_operations proc_rtas_log_operations = {
398 	.read =		rtas_log_read,
399 	.poll =		rtas_log_poll,
400 	.open =		rtas_log_open,
401 	.release =	rtas_log_release,
402 	.llseek =	noop_llseek,
403 };
404 
405 static int enable_surveillance(int timeout)
406 {
407 	int error;
408 
409 	error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);
410 
411 	if (error == 0)
412 		return 0;
413 
414 	if (error == -EINVAL) {
415 		printk(KERN_DEBUG "rtasd: surveillance not supported\n");
416 		return 0;
417 	}
418 
419 	printk(KERN_ERR "rtasd: could not update surveillance\n");
420 	return -1;
421 }
422 
423 static void do_event_scan(void)
424 {
425 	int error;
426 	do {
427 		memset(logdata, 0, rtas_error_log_max);
428 		error = rtas_call(event_scan, 4, 1, NULL,
429 				  RTAS_EVENT_SCAN_ALL_EVENTS, 0,
430 				  __pa(logdata), rtas_error_log_max);
431 		if (error == -1) {
432 			printk(KERN_ERR "event-scan failed\n");
433 			break;
434 		}
435 
436 		if (error == 0) {
437 			pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 0);
438 			handle_rtas_event((struct rtas_error_log *)logdata);
439 		}
440 
441 	} while(error == 0);
442 }
443 
444 static void rtas_event_scan(struct work_struct *w);
445 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);
446 
447 /*
448  * Delay should be at least one second since some machines have problems if
449  * we call event-scan too quickly.
450  */
451 static unsigned long event_scan_delay = 1*HZ;
452 static int first_pass = 1;
453 
454 static void rtas_event_scan(struct work_struct *w)
455 {
456 	unsigned int cpu;
457 
458 	do_event_scan();
459 
460 	get_online_cpus();
461 
462 	/* raw_ OK because just using CPU as starting point. */
463 	cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
464         if (cpu >= nr_cpu_ids) {
465 		cpu = cpumask_first(cpu_online_mask);
466 
467 		if (first_pass) {
468 			first_pass = 0;
469 			event_scan_delay = 30*HZ/rtas_event_scan_rate;
470 
471 			if (surveillance_timeout != -1) {
472 				pr_debug("rtasd: enabling surveillance\n");
473 				enable_surveillance(surveillance_timeout);
474 				pr_debug("rtasd: surveillance enabled\n");
475 			}
476 		}
477 	}
478 
479 	schedule_delayed_work_on(cpu, &event_scan_work,
480 		__round_jiffies_relative(event_scan_delay, cpu));
481 
482 	put_online_cpus();
483 }
484 
485 #ifdef CONFIG_PPC64
486 static void retrieve_nvram_error_log(void)
487 {
488 	unsigned int err_type ;
489 	int rc ;
490 
491 	/* See if we have any error stored in NVRAM */
492 	memset(logdata, 0, rtas_error_log_max);
493 	rc = nvram_read_error_log(logdata, rtas_error_log_max,
494 	                          &err_type, &error_log_cnt);
495 	/* We can use rtas_log_buf now */
496 	logging_enabled = 1;
497 	if (!rc) {
498 		if (err_type != ERR_FLAG_ALREADY_LOGGED) {
499 			pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
500 		}
501 	}
502 }
503 #else /* CONFIG_PPC64 */
504 static void retrieve_nvram_error_log(void)
505 {
506 }
507 #endif /* CONFIG_PPC64 */
508 
509 static void start_event_scan(void)
510 {
511 	printk(KERN_DEBUG "RTAS daemon started\n");
512 	pr_debug("rtasd: will sleep for %d milliseconds\n",
513 		 (30000 / rtas_event_scan_rate));
514 
515 	/* Retrieve errors from nvram if any */
516 	retrieve_nvram_error_log();
517 
518 	schedule_delayed_work_on(cpumask_first(cpu_online_mask),
519 				 &event_scan_work, event_scan_delay);
520 }
521 
522 /* Cancel the rtas event scan work */
523 void rtas_cancel_event_scan(void)
524 {
525 	cancel_delayed_work_sync(&event_scan_work);
526 }
527 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
528 
529 static int __init rtas_event_scan_init(void)
530 {
531 	if (!machine_is(pseries) && !machine_is(chrp))
532 		return 0;
533 
534 	/* No RTAS */
535 	event_scan = rtas_token("event-scan");
536 	if (event_scan == RTAS_UNKNOWN_SERVICE) {
537 		printk(KERN_INFO "rtasd: No event-scan on system\n");
538 		return -ENODEV;
539 	}
540 
541 	rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
542 	if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
543 		printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
544 		return -ENODEV;
545 	}
546 
547 	if (!rtas_event_scan_rate) {
548 		/* Broken firmware: take a rate of zero to mean don't scan */
549 		printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
550 		return 0;
551 	}
552 
553 	/* Make room for the sequence number */
554 	rtas_error_log_max = rtas_get_error_log_max();
555 	rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
556 
557 	rtas_log_buf = vmalloc(rtas_error_log_buffer_max*LOG_NUMBER);
558 	if (!rtas_log_buf) {
559 		printk(KERN_ERR "rtasd: no memory\n");
560 		return -ENOMEM;
561 	}
562 
563 	start_event_scan();
564 
565 	return 0;
566 }
567 arch_initcall(rtas_event_scan_init);
568 
569 static int __init rtas_init(void)
570 {
571 	struct proc_dir_entry *entry;
572 
573 	if (!machine_is(pseries) && !machine_is(chrp))
574 		return 0;
575 
576 	if (!rtas_log_buf)
577 		return -ENODEV;
578 
579 	entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
580 			    &proc_rtas_log_operations);
581 	if (!entry)
582 		printk(KERN_ERR "Failed to create error_log proc entry\n");
583 
584 	return 0;
585 }
586 __initcall(rtas_init);
587 
588 static int __init surveillance_setup(char *str)
589 {
590 	int i;
591 
592 	/* We only do surveillance on pseries */
593 	if (!machine_is(pseries))
594 		return 0;
595 
596 	if (get_option(&str,&i)) {
597 		if (i >= 0 && i <= 255)
598 			surveillance_timeout = i;
599 	}
600 
601 	return 1;
602 }
603 __setup("surveillance=", surveillance_setup);
604 
605 static int __init rtasmsgs_setup(char *str)
606 {
607 	return (kstrtobool(str, &full_rtas_msgs) == 0);
608 }
609 __setup("rtasmsgs=", rtasmsgs_setup);
610