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 <asm/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
35static DEFINE_SPINLOCK(rtasd_log_lock);
36
37static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
38
39static char *rtas_log_buf;
40static unsigned long rtas_log_start;
41static unsigned long rtas_log_size;
42
43static int surveillance_timeout = -1;
44
45static unsigned int rtas_error_log_max;
46static unsigned int rtas_error_log_buffer_max;
47
48/* RTAS service tokens */
49static unsigned int event_scan;
50static unsigned int rtas_event_scan_rate;
51
52static int full_rtas_msgs = 0;
53
54/* Stop logging to nvram after first fatal error */
55static int logging_enabled; /* Until we initialize everything,
56                             * make sure we don't try logging
57                             * anything */
58static 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 */
65static unsigned char logdata[RTAS_ERROR_LOG_MAX];
66
67static 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
73static 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 */
111static 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
158static 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 */
197void 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
276static s32 prrn_update_scope;
277
278static 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
287static DECLARE_WORK(prrn_work, prrn_work_fn);
288
289static void prrn_schedule_update(u32 scope)
290{
291	flush_work(&prrn_work);
292	prrn_update_scope = scope;
293	schedule_work(&prrn_work);
294}
295
296static 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
309static void handle_rtas_event(const struct rtas_error_log *log)
310{
311	return;
312}
313
314#endif
315
316static int rtas_log_open(struct inode * inode, struct file * file)
317{
318	return 0;
319}
320
321static 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 */
330static 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;
384out:
385	kfree(tmp);
386	return error;
387}
388
389static 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
397static 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
405static 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
423static 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
444static void rtas_event_scan(struct work_struct *w);
445DECLARE_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 */
451static unsigned long event_scan_delay = 1*HZ;
452static int first_pass = 1;
453
454static 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
486static void retreive_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 */
504static void retreive_nvram_error_log(void)
505{
506}
507#endif /* CONFIG_PPC64 */
508
509static 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	retreive_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 */
523void rtas_cancel_event_scan(void)
524{
525	cancel_delayed_work_sync(&event_scan_work);
526}
527EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
528
529static int __init rtas_init(void)
530{
531	struct proc_dir_entry *entry;
532
533	if (!machine_is(pseries) && !machine_is(chrp))
534		return 0;
535
536	/* No RTAS */
537	event_scan = rtas_token("event-scan");
538	if (event_scan == RTAS_UNKNOWN_SERVICE) {
539		printk(KERN_INFO "rtasd: No event-scan on system\n");
540		return -ENODEV;
541	}
542
543	rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
544	if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
545		printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
546		return -ENODEV;
547	}
548
549	if (!rtas_event_scan_rate) {
550		/* Broken firmware: take a rate of zero to mean don't scan */
551		printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
552		return 0;
553	}
554
555	/* Make room for the sequence number */
556	rtas_error_log_max = rtas_get_error_log_max();
557	rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
558
559	rtas_log_buf = vmalloc(rtas_error_log_buffer_max*LOG_NUMBER);
560	if (!rtas_log_buf) {
561		printk(KERN_ERR "rtasd: no memory\n");
562		return -ENOMEM;
563	}
564
565	entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
566			    &proc_rtas_log_operations);
567	if (!entry)
568		printk(KERN_ERR "Failed to create error_log proc entry\n");
569
570	start_event_scan();
571
572	return 0;
573}
574__initcall(rtas_init);
575
576static int __init surveillance_setup(char *str)
577{
578	int i;
579
580	/* We only do surveillance on pseries */
581	if (!machine_is(pseries))
582		return 0;
583
584	if (get_option(&str,&i)) {
585		if (i >= 0 && i <= 255)
586			surveillance_timeout = i;
587	}
588
589	return 1;
590}
591__setup("surveillance=", surveillance_setup);
592
593static int __init rtasmsgs_setup(char *str)
594{
595	if (strcmp(str, "on") == 0)
596		full_rtas_msgs = 1;
597	else if (strcmp(str, "off") == 0)
598		full_rtas_msgs = 0;
599
600	return 1;
601}
602__setup("rtasmsgs=", rtasmsgs_setup);
603