xref: /openbmc/linux/arch/powerpc/kernel/rtasd.c (revision c127d130) 
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/nvram.h>
26 #include <linux/atomic.h>
27 #include <asm/machdep.h>
28 #include <asm/topology.h>
29 
30 
31 static DEFINE_SPINLOCK(rtasd_log_lock);
32 
33 static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
34 
35 static char *rtas_log_buf;
36 static unsigned long rtas_log_start;
37 static unsigned long rtas_log_size;
38 
39 static int surveillance_timeout = -1;
40 
41 static unsigned int rtas_error_log_max;
42 static unsigned int rtas_error_log_buffer_max;
43 
44 /* RTAS service tokens */
45 static unsigned int event_scan;
46 static unsigned int rtas_event_scan_rate;
47 
48 static bool full_rtas_msgs;
49 
50 /* Stop logging to nvram after first fatal error */
51 static int logging_enabled; /* Until we initialize everything,
52                              * make sure we don't try logging
53                              * anything */
54 static int error_log_cnt;
55 
56 /*
57  * Since we use 32 bit RTAS, the physical address of this must be below
58  * 4G or else bad things happen. Allocate this in the kernel data and
59  * make it big enough.
60  */
61 static unsigned char logdata[RTAS_ERROR_LOG_MAX];
62 
63 static char *rtas_type[] = {
64 	"Unknown", "Retry", "TCE Error", "Internal Device Failure",
65 	"Timeout", "Data Parity", "Address Parity", "Cache Parity",
66 	"Address Invalid", "ECC Uncorrected", "ECC Corrupted",
67 };
68 
69 static char *rtas_event_type(int type)
70 {
71 	if ((type > 0) && (type < 11))
72 		return rtas_type[type];
73 
74 	switch (type) {
75 		case RTAS_TYPE_EPOW:
76 			return "EPOW";
77 		case RTAS_TYPE_PLATFORM:
78 			return "Platform Error";
79 		case RTAS_TYPE_IO:
80 			return "I/O Event";
81 		case RTAS_TYPE_INFO:
82 			return "Platform Information Event";
83 		case RTAS_TYPE_DEALLOC:
84 			return "Resource Deallocation Event";
85 		case RTAS_TYPE_DUMP:
86 			return "Dump Notification Event";
87 		case RTAS_TYPE_PRRN:
88 			return "Platform Resource Reassignment Event";
89 		case RTAS_TYPE_HOTPLUG:
90 			return "Hotplug Event";
91 	}
92 
93 	return rtas_type[0];
94 }
95 
96 /* To see this info, grep RTAS /var/log/messages and each entry
97  * will be collected together with obvious begin/end.
98  * There will be a unique identifier on the begin and end lines.
99  * This will persist across reboots.
100  *
101  * format of error logs returned from RTAS:
102  * bytes	(size)	: contents
103  * --------------------------------------------------------
104  * 0-7		(8)	: rtas_error_log
105  * 8-47		(40)	: extended info
106  * 48-51	(4)	: vendor id
107  * 52-1023 (vendor specific) : location code and debug data
108  */
109 static void printk_log_rtas(char *buf, int len)
110 {
111 
112 	int i,j,n = 0;
113 	int perline = 16;
114 	char buffer[64];
115 	char * str = "RTAS event";
116 
117 	if (full_rtas_msgs) {
118 		printk(RTAS_DEBUG "%d -------- %s begin --------\n",
119 		       error_log_cnt, str);
120 
121 		/*
122 		 * Print perline bytes on each line, each line will start
123 		 * with RTAS and a changing number, so syslogd will
124 		 * print lines that are otherwise the same.  Separate every
125 		 * 4 bytes with a space.
126 		 */
127 		for (i = 0; i < len; i++) {
128 			j = i % perline;
129 			if (j == 0) {
130 				memset(buffer, 0, sizeof(buffer));
131 				n = sprintf(buffer, "RTAS %d:", i/perline);
132 			}
133 
134 			if ((i % 4) == 0)
135 				n += sprintf(buffer+n, " ");
136 
137 			n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]);
138 
139 			if (j == (perline-1))
140 				printk(KERN_DEBUG "%s\n", buffer);
141 		}
142 		if ((i % perline) != 0)
143 			printk(KERN_DEBUG "%s\n", buffer);
144 
145 		printk(RTAS_DEBUG "%d -------- %s end ----------\n",
146 		       error_log_cnt, str);
147 	} else {
148 		struct rtas_error_log *errlog = (struct rtas_error_log *)buf;
149 
150 		printk(RTAS_DEBUG "event: %d, Type: %s (%d), Severity: %d\n",
151 		       error_log_cnt,
152 		       rtas_event_type(rtas_error_type(errlog)),
153 		       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 static void handle_rtas_event(const struct rtas_error_log *log)
276 {
277 	if (!machine_is(pseries))
278 		return;
279 
280 	if (rtas_error_type(log) == RTAS_TYPE_PRRN)
281 		pr_info_ratelimited("Platform resource reassignment ignored.\n");
282 }
283 
284 static int rtas_log_open(struct inode * inode, struct file * file)
285 {
286 	return 0;
287 }
288 
289 static int rtas_log_release(struct inode * inode, struct file * file)
290 {
291 	return 0;
292 }
293 
294 /* This will check if all events are logged, if they are then, we
295  * know that we can safely clear the events in NVRAM.
296  * Next we'll sit and wait for something else to log.
297  */
298 static ssize_t rtas_log_read(struct file * file, char __user * buf,
299 			 size_t count, loff_t *ppos)
300 {
301 	int error;
302 	char *tmp;
303 	unsigned long s;
304 	unsigned long offset;
305 
306 	if (!buf || count < rtas_error_log_buffer_max)
307 		return -EINVAL;
308 
309 	count = rtas_error_log_buffer_max;
310 
311 	if (!access_ok(buf, count))
312 		return -EFAULT;
313 
314 	tmp = kmalloc(count, GFP_KERNEL);
315 	if (!tmp)
316 		return -ENOMEM;
317 
318 	spin_lock_irqsave(&rtasd_log_lock, s);
319 
320 	/* if it's 0, then we know we got the last one (the one in NVRAM) */
321 	while (rtas_log_size == 0) {
322 		if (file->f_flags & O_NONBLOCK) {
323 			spin_unlock_irqrestore(&rtasd_log_lock, s);
324 			error = -EAGAIN;
325 			goto out;
326 		}
327 
328 		if (!logging_enabled) {
329 			spin_unlock_irqrestore(&rtasd_log_lock, s);
330 			error = -ENODATA;
331 			goto out;
332 		}
333 #ifdef CONFIG_PPC64
334 		nvram_clear_error_log();
335 #endif /* CONFIG_PPC64 */
336 
337 		spin_unlock_irqrestore(&rtasd_log_lock, s);
338 		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
339 		if (error)
340 			goto out;
341 		spin_lock_irqsave(&rtasd_log_lock, s);
342 	}
343 
344 	offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
345 	memcpy(tmp, &rtas_log_buf[offset], count);
346 
347 	rtas_log_start += 1;
348 	rtas_log_size -= 1;
349 	spin_unlock_irqrestore(&rtasd_log_lock, s);
350 
351 	error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
352 out:
353 	kfree(tmp);
354 	return error;
355 }
356 
357 static __poll_t rtas_log_poll(struct file *file, poll_table * wait)
358 {
359 	poll_wait(file, &rtas_log_wait, wait);
360 	if (rtas_log_size)
361 		return EPOLLIN | EPOLLRDNORM;
362 	return 0;
363 }
364 
365 static const struct proc_ops rtas_log_proc_ops = {
366 	.proc_read	= rtas_log_read,
367 	.proc_poll	= rtas_log_poll,
368 	.proc_open	= rtas_log_open,
369 	.proc_release	= rtas_log_release,
370 	.proc_lseek	= noop_llseek,
371 };
372 
373 static int enable_surveillance(int timeout)
374 {
375 	int error;
376 
377 	error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);
378 
379 	if (error == 0)
380 		return 0;
381 
382 	if (error == -EINVAL) {
383 		printk(KERN_DEBUG "rtasd: surveillance not supported\n");
384 		return 0;
385 	}
386 
387 	printk(KERN_ERR "rtasd: could not update surveillance\n");
388 	return -1;
389 }
390 
391 static void do_event_scan(void)
392 {
393 	int error;
394 	do {
395 		memset(logdata, 0, rtas_error_log_max);
396 		error = rtas_call(event_scan, 4, 1, NULL,
397 				  RTAS_EVENT_SCAN_ALL_EVENTS, 0,
398 				  __pa(logdata), rtas_error_log_max);
399 		if (error == -1) {
400 			printk(KERN_ERR "event-scan failed\n");
401 			break;
402 		}
403 
404 		if (error == 0) {
405 			if (rtas_error_type((struct rtas_error_log *)logdata) !=
406 			    RTAS_TYPE_PRRN)
407 				pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG,
408 						  0);
409 			handle_rtas_event((struct rtas_error_log *)logdata);
410 		}
411 
412 	} while(error == 0);
413 }
414 
415 static void rtas_event_scan(struct work_struct *w);
416 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);
417 
418 /*
419  * Delay should be at least one second since some machines have problems if
420  * we call event-scan too quickly.
421  */
422 static unsigned long event_scan_delay = 1*HZ;
423 static int first_pass = 1;
424 
425 static void rtas_event_scan(struct work_struct *w)
426 {
427 	unsigned int cpu;
428 
429 	do_event_scan();
430 
431 	cpus_read_lock();
432 
433 	/* raw_ OK because just using CPU as starting point. */
434 	cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
435         if (cpu >= nr_cpu_ids) {
436 		cpu = cpumask_first(cpu_online_mask);
437 
438 		if (first_pass) {
439 			first_pass = 0;
440 			event_scan_delay = 30*HZ/rtas_event_scan_rate;
441 
442 			if (surveillance_timeout != -1) {
443 				pr_debug("rtasd: enabling surveillance\n");
444 				enable_surveillance(surveillance_timeout);
445 				pr_debug("rtasd: surveillance enabled\n");
446 			}
447 		}
448 	}
449 
450 	schedule_delayed_work_on(cpu, &event_scan_work,
451 		__round_jiffies_relative(event_scan_delay, cpu));
452 
453 	cpus_read_unlock();
454 }
455 
456 #ifdef CONFIG_PPC64
457 static void __init retrieve_nvram_error_log(void)
458 {
459 	unsigned int err_type ;
460 	int rc ;
461 
462 	/* See if we have any error stored in NVRAM */
463 	memset(logdata, 0, rtas_error_log_max);
464 	rc = nvram_read_error_log(logdata, rtas_error_log_max,
465 	                          &err_type, &error_log_cnt);
466 	/* We can use rtas_log_buf now */
467 	logging_enabled = 1;
468 	if (!rc) {
469 		if (err_type != ERR_FLAG_ALREADY_LOGGED) {
470 			pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
471 		}
472 	}
473 }
474 #else /* CONFIG_PPC64 */
475 static void __init retrieve_nvram_error_log(void)
476 {
477 }
478 #endif /* CONFIG_PPC64 */
479 
480 static void __init start_event_scan(void)
481 {
482 	printk(KERN_DEBUG "RTAS daemon started\n");
483 	pr_debug("rtasd: will sleep for %d milliseconds\n",
484 		 (30000 / rtas_event_scan_rate));
485 
486 	/* Retrieve errors from nvram if any */
487 	retrieve_nvram_error_log();
488 
489 	schedule_delayed_work_on(cpumask_first(cpu_online_mask),
490 				 &event_scan_work, event_scan_delay);
491 }
492 
493 /* Cancel the rtas event scan work */
494 void rtas_cancel_event_scan(void)
495 {
496 	cancel_delayed_work_sync(&event_scan_work);
497 }
498 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
499 
500 static int __init rtas_event_scan_init(void)
501 {
502 	if (!machine_is(pseries) && !machine_is(chrp))
503 		return 0;
504 
505 	/* No RTAS */
506 	event_scan = rtas_token("event-scan");
507 	if (event_scan == RTAS_UNKNOWN_SERVICE) {
508 		printk(KERN_INFO "rtasd: No event-scan on system\n");
509 		return -ENODEV;
510 	}
511 
512 	rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
513 	if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
514 		printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
515 		return -ENODEV;
516 	}
517 
518 	if (!rtas_event_scan_rate) {
519 		/* Broken firmware: take a rate of zero to mean don't scan */
520 		printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
521 		return 0;
522 	}
523 
524 	/* Make room for the sequence number */
525 	rtas_error_log_max = rtas_get_error_log_max();
526 	rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
527 
528 	rtas_log_buf = vmalloc(array_size(LOG_NUMBER,
529 					  rtas_error_log_buffer_max));
530 	if (!rtas_log_buf) {
531 		printk(KERN_ERR "rtasd: no memory\n");
532 		return -ENOMEM;
533 	}
534 
535 	start_event_scan();
536 
537 	return 0;
538 }
539 arch_initcall(rtas_event_scan_init);
540 
541 static int __init rtas_init(void)
542 {
543 	struct proc_dir_entry *entry;
544 
545 	if (!machine_is(pseries) && !machine_is(chrp))
546 		return 0;
547 
548 	if (!rtas_log_buf)
549 		return -ENODEV;
550 
551 	entry = proc_create("powerpc/rtas/error_log", 0400, NULL,
552 			    &rtas_log_proc_ops);
553 	if (!entry)
554 		printk(KERN_ERR "Failed to create error_log proc entry\n");
555 
556 	return 0;
557 }
558 __initcall(rtas_init);
559 
560 static int __init surveillance_setup(char *str)
561 {
562 	int i;
563 
564 	/* We only do surveillance on pseries */
565 	if (!machine_is(pseries))
566 		return 0;
567 
568 	if (get_option(&str,&i)) {
569 		if (i >= 0 && i <= 255)
570 			surveillance_timeout = i;
571 	}
572 
573 	return 1;
574 }
575 __setup("surveillance=", surveillance_setup);
576 
577 static int __init rtasmsgs_setup(char *str)
578 {
579 	return (kstrtobool(str, &full_rtas_msgs) == 0);
580 }
581 __setup("rtasmsgs=", rtasmsgs_setup);
582