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
32 static DEFINE_SPINLOCK(rtasd_log_lock);
33
34 static DECLARE_WAIT_QUEUE_HEAD(rtas_log_wait);
35
36 static char *rtas_log_buf;
37 static unsigned long rtas_log_start;
38 static unsigned long rtas_log_size;
39
40 static int surveillance_timeout = -1;
41
42 static unsigned int rtas_error_log_max;
43 static unsigned int rtas_error_log_buffer_max;
44
45 /* RTAS service tokens */
46 static unsigned int event_scan;
47 static unsigned int rtas_event_scan_rate;
48
49 static bool full_rtas_msgs;
50
51 /* Stop logging to nvram after first fatal error */
52 static int logging_enabled; /* Until we initialize everything,
53 * make sure we don't try logging
54 * anything */
55 static 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 */
62 static unsigned char logdata[RTAS_ERROR_LOG_MAX];
63
64 static 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
70 static 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 */
110 static 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
159 static 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 */
198 void 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
276 static 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
285 static int rtas_log_open(struct inode * inode, struct file * file)
286 {
287 return 0;
288 }
289
290 static 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 */
299 static 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;
353 out:
354 kfree(tmp);
355 return error;
356 }
357
358 static __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
366 static 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
374 static 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
392 static 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
416 static void rtas_event_scan(struct work_struct *w);
417 static 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 */
423 static unsigned long event_scan_delay = 1*HZ;
424 static int first_pass = 1;
425
426 static 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
458 static 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 */
476 static void __init retrieve_nvram_error_log(void)
477 {
478 }
479 #endif /* CONFIG_PPC64 */
480
481 static 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 */
495 void rtas_cancel_event_scan(void)
496 {
497 cancel_delayed_work_sync(&event_scan_work);
498 }
499 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
500
501 static 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 }
542 arch_initcall(rtas_event_scan_init);
543
544 static 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
563 static 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
580 static int __init rtasmsgs_setup(char *str)
581 {
582 return (kstrtobool(str, &full_rtas_msgs) == 0);
583 }
584 __setup("rtasmsgs=", rtasmsgs_setup);
585
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.