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
rtas_event_type(int type)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 */
printk_log_rtas(char * buf,int len)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
log_rtas_len(char * buf)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 */
pSeries_log_error(char * buf,unsigned int err_type,int fatal)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
handle_rtas_event(const struct rtas_error_log * log)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
rtas_log_open(struct inode * inode,struct file * file)284 static int rtas_log_open(struct inode * inode, struct file * file)
285 {
286 return 0;
287 }
288
rtas_log_release(struct inode * inode,struct file * file)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 */
rtas_log_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)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
rtas_log_poll(struct file * file,poll_table * wait)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
enable_surveillance(int timeout)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
do_event_scan(void)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
rtas_event_scan(struct work_struct * w)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
retrieve_nvram_error_log(void)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 */
retrieve_nvram_error_log(void)475 static void __init retrieve_nvram_error_log(void)
476 {
477 }
478 #endif /* CONFIG_PPC64 */
479
start_event_scan(void)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 */
rtas_cancel_event_scan(void)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
rtas_event_scan_init(void)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
rtas_init(void)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
surveillance_setup(char * str)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
rtasmsgs_setup(char * str)577 static int __init rtasmsgs_setup(char *str)
578 {
579 return (kstrtobool(str, &full_rtas_msgs) == 0);
580 }
581 __setup("rtasmsgs=", rtasmsgs_setup);
582