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