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/of.h>
13#include <linux/poll.h>
14#include <linux/proc_fs.h>
15#include <linux/init.h>
16#include <linux/vmalloc.h>
17#include <linux/spinlock.h>
18#include <linux/cpu.h>
19#include <linux/workqueue.h>
20#include <linux/slab.h>
21#include <linux/topology.h>
22
23#include <linux/uaccess.h>
24#include <asm/io.h>
25#include <asm/rtas.h>
26#include <asm/nvram.h>
27#include <linux/atomic.h>
28#include <asm/machdep.h>
29#include <asm/topology.h>
30
31
32static DEFINE_SPINLOCK(rtasd_log_lock);
33
34static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
35
36static char *rtas_log_buf;
37static unsigned long rtas_log_start;
38static unsigned long rtas_log_size;
39
40static int surveillance_timeout = -1;
41
42static unsigned int rtas_error_log_max;
43static unsigned int rtas_error_log_buffer_max;
44
45/* RTAS service tokens */
46static unsigned int event_scan;
47static unsigned int rtas_event_scan_rate;
48
49static bool full_rtas_msgs;
50
51/* Stop logging to nvram after first fatal error */
52static int logging_enabled; /* Until we initialize everything,
53                             * make sure we don't try logging
54                             * anything */
55static 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 */
62static unsigned char logdata[RTAS_ERROR_LOG_MAX];
63
64static 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
70static 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 */
110static 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
159static 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 */
198void 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
276static void handle_rtas_event(const struct rtas_error_log *log)
277{
278	if (!machine_is(pseries))
279		return;
280
281	if (rtas_error_type(log) == RTAS_TYPE_PRRN)
282		pr_info_ratelimited("Platform resource reassignment ignored.\n");
283}
284
285static int rtas_log_open(struct inode * inode, struct file * file)
286{
287	return 0;
288}
289
290static int rtas_log_release(struct inode * inode, struct file * file)
291{
292	return 0;
293}
294
295/* This will check if all events are logged, if they are then, we
296 * know that we can safely clear the events in NVRAM.
297 * Next we'll sit and wait for something else to log.
298 */
299static ssize_t rtas_log_read(struct file * file, char __user * buf,
300			 size_t count, loff_t *ppos)
301{
302	int error;
303	char *tmp;
304	unsigned long s;
305	unsigned long offset;
306
307	if (!buf || count < rtas_error_log_buffer_max)
308		return -EINVAL;
309
310	count = rtas_error_log_buffer_max;
311
312	if (!access_ok(buf, count))
313		return -EFAULT;
314
315	tmp = kmalloc(count, GFP_KERNEL);
316	if (!tmp)
317		return -ENOMEM;
318
319	spin_lock_irqsave(&rtasd_log_lock, s);
320
321	/* if it's 0, then we know we got the last one (the one in NVRAM) */
322	while (rtas_log_size == 0) {
323		if (file->f_flags & O_NONBLOCK) {
324			spin_unlock_irqrestore(&rtasd_log_lock, s);
325			error = -EAGAIN;
326			goto out;
327		}
328
329		if (!logging_enabled) {
330			spin_unlock_irqrestore(&rtasd_log_lock, s);
331			error = -ENODATA;
332			goto out;
333		}
334#ifdef CONFIG_PPC64
335		nvram_clear_error_log();
336#endif /* CONFIG_PPC64 */
337
338		spin_unlock_irqrestore(&rtasd_log_lock, s);
339		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
340		if (error)
341			goto out;
342		spin_lock_irqsave(&rtasd_log_lock, s);
343	}
344
345	offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
346	memcpy(tmp, &rtas_log_buf[offset], count);
347
348	rtas_log_start += 1;
349	rtas_log_size -= 1;
350	spin_unlock_irqrestore(&rtasd_log_lock, s);
351
352	error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
353out:
354	kfree(tmp);
355	return error;
356}
357
358static __poll_t rtas_log_poll(struct file *file, poll_table * wait)
359{
360	poll_wait(file, &rtas_log_wait, wait);
361	if (rtas_log_size)
362		return EPOLLIN | EPOLLRDNORM;
363	return 0;
364}
365
366static const struct proc_ops rtas_log_proc_ops = {
367	.proc_read	= rtas_log_read,
368	.proc_poll	= rtas_log_poll,
369	.proc_open	= rtas_log_open,
370	.proc_release	= rtas_log_release,
371	.proc_lseek	= noop_llseek,
372};
373
374static int enable_surveillance(int timeout)
375{
376	int error;
377
378	error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);
379
380	if (error == 0)
381		return 0;
382
383	if (error == -EINVAL) {
384		printk(KERN_DEBUG "rtasd: surveillance not supported\n");
385		return 0;
386	}
387
388	printk(KERN_ERR "rtasd: could not update surveillance\n");
389	return -1;
390}
391
392static void do_event_scan(void)
393{
394	int error;
395	do {
396		memset(logdata, 0, rtas_error_log_max);
397		error = rtas_call(event_scan, 4, 1, NULL,
398				  RTAS_EVENT_SCAN_ALL_EVENTS, 0,
399				  __pa(logdata), rtas_error_log_max);
400		if (error == -1) {
401			printk(KERN_ERR "event-scan failed\n");
402			break;
403		}
404
405		if (error == 0) {
406			if (rtas_error_type((struct rtas_error_log *)logdata) !=
407			    RTAS_TYPE_PRRN)
408				pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG,
409						  0);
410			handle_rtas_event((struct rtas_error_log *)logdata);
411		}
412
413	} while(error == 0);
414}
415
416static void rtas_event_scan(struct work_struct *w);
417static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);
418
419/*
420 * Delay should be at least one second since some machines have problems if
421 * we call event-scan too quickly.
422 */
423static unsigned long event_scan_delay = 1*HZ;
424static int first_pass = 1;
425
426static void rtas_event_scan(struct work_struct *w)
427{
428	unsigned int cpu;
429
430	do_event_scan();
431
432	cpus_read_lock();
433
434	/* raw_ OK because just using CPU as starting point. */
435	cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
436        if (cpu >= nr_cpu_ids) {
437		cpu = cpumask_first(cpu_online_mask);
438
439		if (first_pass) {
440			first_pass = 0;
441			event_scan_delay = 30*HZ/rtas_event_scan_rate;
442
443			if (surveillance_timeout != -1) {
444				pr_debug("rtasd: enabling surveillance\n");
445				enable_surveillance(surveillance_timeout);
446				pr_debug("rtasd: surveillance enabled\n");
447			}
448		}
449	}
450
451	schedule_delayed_work_on(cpu, &event_scan_work,
452		__round_jiffies_relative(event_scan_delay, cpu));
453
454	cpus_read_unlock();
455}
456
457#ifdef CONFIG_PPC64
458static void __init retrieve_nvram_error_log(void)
459{
460	unsigned int err_type ;
461	int rc ;
462
463	/* See if we have any error stored in NVRAM */
464	memset(logdata, 0, rtas_error_log_max);
465	rc = nvram_read_error_log(logdata, rtas_error_log_max,
466	                          &err_type, &error_log_cnt);
467	/* We can use rtas_log_buf now */
468	logging_enabled = 1;
469	if (!rc) {
470		if (err_type != ERR_FLAG_ALREADY_LOGGED) {
471			pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
472		}
473	}
474}
475#else /* CONFIG_PPC64 */
476static void __init retrieve_nvram_error_log(void)
477{
478}
479#endif /* CONFIG_PPC64 */
480
481static void __init start_event_scan(void)
482{
483	printk(KERN_DEBUG "RTAS daemon started\n");
484	pr_debug("rtasd: will sleep for %d milliseconds\n",
485		 (30000 / rtas_event_scan_rate));
486
487	/* Retrieve errors from nvram if any */
488	retrieve_nvram_error_log();
489
490	schedule_delayed_work_on(cpumask_first(cpu_online_mask),
491				 &event_scan_work, event_scan_delay);
492}
493
494/* Cancel the rtas event scan work */
495void rtas_cancel_event_scan(void)
496{
497	cancel_delayed_work_sync(&event_scan_work);
498}
499EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
500
501static int __init rtas_event_scan_init(void)
502{
503	int err;
504
505	if (!machine_is(pseries) && !machine_is(chrp))
506		return 0;
507
508	/* No RTAS */
509	event_scan = rtas_function_token(RTAS_FN_EVENT_SCAN);
510	if (event_scan == RTAS_UNKNOWN_SERVICE) {
511		printk(KERN_INFO "rtasd: No event-scan on system\n");
512		return -ENODEV;
513	}
514
515	err = of_property_read_u32(rtas.dev, "rtas-event-scan-rate", &rtas_event_scan_rate);
516	if (err) {
517		printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
518		return -ENODEV;
519	}
520
521	if (!rtas_event_scan_rate) {
522		/* Broken firmware: take a rate of zero to mean don't scan */
523		printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
524		return 0;
525	}
526
527	/* Make room for the sequence number */
528	rtas_error_log_max = rtas_get_error_log_max();
529	rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
530
531	rtas_log_buf = vmalloc(array_size(LOG_NUMBER,
532					  rtas_error_log_buffer_max));
533	if (!rtas_log_buf) {
534		printk(KERN_ERR "rtasd: no memory\n");
535		return -ENOMEM;
536	}
537
538	start_event_scan();
539
540	return 0;
541}
542arch_initcall(rtas_event_scan_init);
543
544static int __init rtas_init(void)
545{
546	struct proc_dir_entry *entry;
547
548	if (!machine_is(pseries) && !machine_is(chrp))
549		return 0;
550
551	if (!rtas_log_buf)
552		return -ENODEV;
553
554	entry = proc_create("powerpc/rtas/error_log", 0400, NULL,
555			    &rtas_log_proc_ops);
556	if (!entry)
557		printk(KERN_ERR "Failed to create error_log proc entry\n");
558
559	return 0;
560}
561__initcall(rtas_init);
562
563static int __init surveillance_setup(char *str)
564{
565	int i;
566
567	/* We only do surveillance on pseries */
568	if (!machine_is(pseries))
569		return 0;
570
571	if (get_option(&str,&i)) {
572		if (i >= 0 && i <= 255)
573			surveillance_timeout = i;
574	}
575
576	return 1;
577}
578__setup("surveillance=", surveillance_setup);
579
580static int __init rtasmsgs_setup(char *str)
581{
582	return (kstrtobool(str, &full_rtas_msgs) == 0);
583}
584__setup("rtasmsgs=", rtasmsgs_setup);
585