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
rtas_event_type(int type)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 case RTAS_TYPE_HVPIPE:
93 return "Hypervisor Pipe Notification event";
94 }
95
96 return rtas_type[0];
97 }
98
99 /* To see this info, grep RTAS /var/log/messages and each entry
100 * will be collected together with obvious begin/end.
101 * There will be a unique identifier on the begin and end lines.
102 * This will persist across reboots.
103 *
104 * format of error logs returned from RTAS:
105 * bytes (size) : contents
106 * --------------------------------------------------------
107 * 0-7 (8) : rtas_error_log
108 * 8-47 (40) : extended info
109 * 48-51 (4) : vendor id
110 * 52-1023 (vendor specific) : location code and debug data
111 */
printk_log_rtas(char * buf,int len)112 static void printk_log_rtas(char *buf, int len)
113 {
114
115 int i,j,n = 0;
116 int perline = 16;
117 char buffer[64];
118 char * str = "RTAS event";
119
120 if (full_rtas_msgs) {
121 printk(RTAS_DEBUG "%d -------- %s begin --------\n",
122 error_log_cnt, str);
123
124 /*
125 * Print perline bytes on each line, each line will start
126 * with RTAS and a changing number, so syslogd will
127 * print lines that are otherwise the same. Separate every
128 * 4 bytes with a space.
129 */
130 for (i = 0; i < len; i++) {
131 j = i % perline;
132 if (j == 0) {
133 memset(buffer, 0, sizeof(buffer));
134 n = sprintf(buffer, "RTAS %d:", i/perline);
135 }
136
137 if ((i % 4) == 0)
138 n += sprintf(buffer+n, " ");
139
140 n += sprintf(buffer+n, "%02x", (unsigned char)buf[i]);
141
142 if (j == (perline-1))
143 printk(KERN_DEBUG "%s\n", buffer);
144 }
145 if ((i % perline) != 0)
146 printk(KERN_DEBUG "%s\n", buffer);
147
148 printk(RTAS_DEBUG "%d -------- %s end ----------\n",
149 error_log_cnt, str);
150 } else {
151 struct rtas_error_log *errlog = (struct rtas_error_log *)buf;
152
153 printk(RTAS_DEBUG "event: %d, Type: %s (%d), Severity: %d\n",
154 error_log_cnt,
155 rtas_event_type(rtas_error_type(errlog)),
156 rtas_error_type(errlog),
157 rtas_error_severity(errlog));
158 }
159 }
160
log_rtas_len(char * buf)161 static int log_rtas_len(char * buf)
162 {
163 int len;
164 struct rtas_error_log *err;
165 uint32_t extended_log_length;
166
167 /* rtas fixed header */
168 len = 8;
169 err = (struct rtas_error_log *)buf;
170 extended_log_length = rtas_error_extended_log_length(err);
171 if (rtas_error_extended(err) && extended_log_length) {
172
173 /* extended header */
174 len += extended_log_length;
175 }
176
177 if (rtas_error_log_max == 0)
178 rtas_error_log_max = rtas_get_error_log_max();
179
180 if (len > rtas_error_log_max)
181 len = rtas_error_log_max;
182
183 return len;
184 }
185
186 /*
187 * First write to nvram, if fatal error, that is the only
188 * place we log the info. The error will be picked up
189 * on the next reboot by rtasd. If not fatal, run the
190 * method for the type of error. Currently, only RTAS
191 * errors have methods implemented, but in the future
192 * there might be a need to store data in nvram before a
193 * call to panic().
194 *
195 * XXX We write to nvram periodically, to indicate error has
196 * been written and sync'd, but there is a possibility
197 * that if we don't shutdown correctly, a duplicate error
198 * record will be created on next reboot.
199 */
pSeries_log_error(char * buf,unsigned int err_type,int fatal)200 void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
201 {
202 unsigned long offset;
203 unsigned long s;
204 int len = 0;
205
206 pr_debug("rtasd: logging event\n");
207 if (buf == NULL)
208 return;
209
210 spin_lock_irqsave(&rtasd_log_lock, s);
211
212 /* get length and increase count */
213 switch (err_type & ERR_TYPE_MASK) {
214 case ERR_TYPE_RTAS_LOG:
215 len = log_rtas_len(buf);
216 if (!(err_type & ERR_FLAG_BOOT))
217 error_log_cnt++;
218 break;
219 case ERR_TYPE_KERNEL_PANIC:
220 default:
221 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
222 spin_unlock_irqrestore(&rtasd_log_lock, s);
223 return;
224 }
225
226 #ifdef CONFIG_PPC64
227 /* Write error to NVRAM */
228 if (logging_enabled && !(err_type & ERR_FLAG_BOOT))
229 nvram_write_error_log(buf, len, err_type, error_log_cnt);
230 #endif /* CONFIG_PPC64 */
231
232 /*
233 * rtas errors can occur during boot, and we do want to capture
234 * those somewhere, even if nvram isn't ready (why not?), and even
235 * if rtasd isn't ready. Put them into the boot log, at least.
236 */
237 if ((err_type & ERR_TYPE_MASK) == ERR_TYPE_RTAS_LOG)
238 printk_log_rtas(buf, len);
239
240 /* Check to see if we need to or have stopped logging */
241 if (fatal || !logging_enabled) {
242 logging_enabled = 0;
243 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
244 spin_unlock_irqrestore(&rtasd_log_lock, s);
245 return;
246 }
247
248 /* call type specific method for error */
249 switch (err_type & ERR_TYPE_MASK) {
250 case ERR_TYPE_RTAS_LOG:
251 offset = rtas_error_log_buffer_max *
252 ((rtas_log_start+rtas_log_size) & LOG_NUMBER_MASK);
253
254 /* First copy over sequence number */
255 memcpy(&rtas_log_buf[offset], (void *) &error_log_cnt, sizeof(int));
256
257 /* Second copy over error log data */
258 offset += sizeof(int);
259 memcpy(&rtas_log_buf[offset], buf, len);
260
261 if (rtas_log_size < LOG_NUMBER)
262 rtas_log_size += 1;
263 else
264 rtas_log_start += 1;
265
266 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
267 spin_unlock_irqrestore(&rtasd_log_lock, s);
268 wake_up_interruptible(&rtas_log_wait);
269 break;
270 case ERR_TYPE_KERNEL_PANIC:
271 default:
272 WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
273 spin_unlock_irqrestore(&rtasd_log_lock, s);
274 return;
275 }
276 }
277
handle_rtas_event(const struct rtas_error_log * log)278 static void handle_rtas_event(const struct rtas_error_log *log)
279 {
280 if (!machine_is(pseries))
281 return;
282
283 if (rtas_error_type(log) == RTAS_TYPE_PRRN)
284 pr_info_ratelimited("Platform resource reassignment ignored.\n");
285 }
286
rtas_log_open(struct inode * inode,struct file * file)287 static int rtas_log_open(struct inode * inode, struct file * file)
288 {
289 return 0;
290 }
291
rtas_log_release(struct inode * inode,struct file * file)292 static int rtas_log_release(struct inode * inode, struct file * file)
293 {
294 return 0;
295 }
296
297 /* This will check if all events are logged, if they are then, we
298 * know that we can safely clear the events in NVRAM.
299 * Next we'll sit and wait for something else to log.
300 */
rtas_log_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)301 static ssize_t rtas_log_read(struct file * file, char __user * buf,
302 size_t count, loff_t *ppos)
303 {
304 int error;
305 char *tmp;
306 unsigned long s;
307 unsigned long offset;
308
309 if (!buf || count < rtas_error_log_buffer_max)
310 return -EINVAL;
311
312 count = rtas_error_log_buffer_max;
313
314 if (!access_ok(buf, count))
315 return -EFAULT;
316
317 tmp = kmalloc(count, GFP_KERNEL);
318 if (!tmp)
319 return -ENOMEM;
320
321 spin_lock_irqsave(&rtasd_log_lock, s);
322
323 /* if it's 0, then we know we got the last one (the one in NVRAM) */
324 while (rtas_log_size == 0) {
325 if (file->f_flags & O_NONBLOCK) {
326 spin_unlock_irqrestore(&rtasd_log_lock, s);
327 error = -EAGAIN;
328 goto out;
329 }
330
331 if (!logging_enabled) {
332 spin_unlock_irqrestore(&rtasd_log_lock, s);
333 error = -ENODATA;
334 goto out;
335 }
336 #ifdef CONFIG_PPC64
337 nvram_clear_error_log();
338 #endif /* CONFIG_PPC64 */
339
340 spin_unlock_irqrestore(&rtasd_log_lock, s);
341 error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
342 if (error)
343 goto out;
344 spin_lock_irqsave(&rtasd_log_lock, s);
345 }
346
347 offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK);
348 memcpy(tmp, &rtas_log_buf[offset], count);
349
350 rtas_log_start += 1;
351 rtas_log_size -= 1;
352 spin_unlock_irqrestore(&rtasd_log_lock, s);
353
354 error = copy_to_user(buf, tmp, count) ? -EFAULT : count;
355 out:
356 kfree(tmp);
357 return error;
358 }
359
rtas_log_poll(struct file * file,poll_table * wait)360 static __poll_t rtas_log_poll(struct file *file, poll_table * wait)
361 {
362 poll_wait(file, &rtas_log_wait, wait);
363 if (rtas_log_size)
364 return EPOLLIN | EPOLLRDNORM;
365 return 0;
366 }
367
368 static const struct proc_ops rtas_log_proc_ops = {
369 .proc_read = rtas_log_read,
370 .proc_poll = rtas_log_poll,
371 .proc_open = rtas_log_open,
372 .proc_release = rtas_log_release,
373 .proc_lseek = noop_llseek,
374 };
375
enable_surveillance(int timeout)376 static int enable_surveillance(int timeout)
377 {
378 int error;
379
380 error = rtas_set_indicator(SURVEILLANCE_TOKEN, 0, timeout);
381
382 if (error == 0)
383 return 0;
384
385 if (error == -EINVAL) {
386 printk(KERN_DEBUG "rtasd: surveillance not supported\n");
387 return 0;
388 }
389
390 printk(KERN_ERR "rtasd: could not update surveillance\n");
391 return -1;
392 }
393
do_event_scan(void)394 static void do_event_scan(void)
395 {
396 int error;
397 do {
398 memset(logdata, 0, rtas_error_log_max);
399 error = rtas_call(event_scan, 4, 1, NULL,
400 RTAS_EVENT_SCAN_ALL_EVENTS, 0,
401 __pa(logdata), rtas_error_log_max);
402 if (error == -1) {
403 printk(KERN_ERR "event-scan failed\n");
404 break;
405 }
406
407 if (error == 0) {
408 if (rtas_error_type((struct rtas_error_log *)logdata) !=
409 RTAS_TYPE_PRRN)
410 pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG,
411 0);
412 handle_rtas_event((struct rtas_error_log *)logdata);
413 }
414
415 } while(error == 0);
416 }
417
418 static void rtas_event_scan(struct work_struct *w);
419 static DECLARE_DELAYED_WORK(event_scan_work, rtas_event_scan);
420
421 /*
422 * Delay should be at least one second since some machines have problems if
423 * we call event-scan too quickly.
424 */
425 static unsigned long event_scan_delay = 1*HZ;
426 static int first_pass = 1;
427
rtas_event_scan(struct work_struct * w)428 static void rtas_event_scan(struct work_struct *w)
429 {
430 unsigned int cpu;
431
432 do_event_scan();
433
434 cpus_read_lock();
435
436 /* raw_ OK because just using CPU as starting point. */
437 cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
438 if (cpu >= nr_cpu_ids) {
439 cpu = cpumask_first(cpu_online_mask);
440
441 if (first_pass) {
442 first_pass = 0;
443 event_scan_delay = 30*HZ/rtas_event_scan_rate;
444
445 if (surveillance_timeout != -1) {
446 pr_debug("rtasd: enabling surveillance\n");
447 enable_surveillance(surveillance_timeout);
448 pr_debug("rtasd: surveillance enabled\n");
449 }
450 }
451 }
452
453 schedule_delayed_work_on(cpu, &event_scan_work,
454 __round_jiffies_relative(event_scan_delay, cpu));
455
456 cpus_read_unlock();
457 }
458
459 #ifdef CONFIG_PPC64
retrieve_nvram_error_log(void)460 static void __init retrieve_nvram_error_log(void)
461 {
462 unsigned int err_type ;
463 int rc ;
464
465 /* See if we have any error stored in NVRAM */
466 memset(logdata, 0, rtas_error_log_max);
467 rc = nvram_read_error_log(logdata, rtas_error_log_max,
468 &err_type, &error_log_cnt);
469 /* We can use rtas_log_buf now */
470 logging_enabled = 1;
471 if (!rc) {
472 if (err_type != ERR_FLAG_ALREADY_LOGGED) {
473 pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
474 }
475 }
476 }
477 #else /* CONFIG_PPC64 */
retrieve_nvram_error_log(void)478 static void __init retrieve_nvram_error_log(void)
479 {
480 }
481 #endif /* CONFIG_PPC64 */
482
start_event_scan(void)483 static void __init start_event_scan(void)
484 {
485 printk(KERN_DEBUG "RTAS daemon started\n");
486 pr_debug("rtasd: will sleep for %d milliseconds\n",
487 (30000 / rtas_event_scan_rate));
488
489 /* Retrieve errors from nvram if any */
490 retrieve_nvram_error_log();
491
492 schedule_delayed_work_on(cpumask_first(cpu_online_mask),
493 &event_scan_work, event_scan_delay);
494 }
495
496 /* Cancel the rtas event scan work */
rtas_cancel_event_scan(void)497 void rtas_cancel_event_scan(void)
498 {
499 cancel_delayed_work_sync(&event_scan_work);
500 }
501 EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
502
rtas_event_scan_init(void)503 static int __init rtas_event_scan_init(void)
504 {
505 int err;
506
507 if (!machine_is(pseries) && !machine_is(chrp))
508 return 0;
509
510 /* No RTAS */
511 event_scan = rtas_function_token(RTAS_FN_EVENT_SCAN);
512 if (event_scan == RTAS_UNKNOWN_SERVICE) {
513 printk(KERN_INFO "rtasd: No event-scan on system\n");
514 return -ENODEV;
515 }
516
517 err = of_property_read_u32(rtas.dev, "rtas-event-scan-rate", &rtas_event_scan_rate);
518 if (err) {
519 printk(KERN_ERR "rtasd: no rtas-event-scan-rate on system\n");
520 return -ENODEV;
521 }
522
523 if (!rtas_event_scan_rate) {
524 /* Broken firmware: take a rate of zero to mean don't scan */
525 printk(KERN_DEBUG "rtasd: scan rate is 0, not scanning\n");
526 return 0;
527 }
528
529 /* Make room for the sequence number */
530 rtas_error_log_max = rtas_get_error_log_max();
531 rtas_error_log_buffer_max = rtas_error_log_max + sizeof(int);
532
533 rtas_log_buf = vmalloc(array_size(LOG_NUMBER,
534 rtas_error_log_buffer_max));
535 if (!rtas_log_buf) {
536 printk(KERN_ERR "rtasd: no memory\n");
537 return -ENOMEM;
538 }
539
540 start_event_scan();
541
542 return 0;
543 }
544 arch_initcall(rtas_event_scan_init);
545
rtas_init(void)546 static int __init rtas_init(void)
547 {
548 struct proc_dir_entry *entry;
549
550 if (!machine_is(pseries) && !machine_is(chrp))
551 return 0;
552
553 if (!rtas_log_buf)
554 return -ENODEV;
555
556 entry = proc_create("powerpc/rtas/error_log", 0400, NULL,
557 &rtas_log_proc_ops);
558 if (!entry)
559 printk(KERN_ERR "Failed to create error_log proc entry\n");
560
561 return 0;
562 }
563 __initcall(rtas_init);
564
surveillance_setup(char * str)565 static int __init surveillance_setup(char *str)
566 {
567 int i;
568
569 /* We only do surveillance on pseries */
570 if (!machine_is(pseries))
571 return 0;
572
573 if (get_option(&str,&i)) {
574 if (i >= 0 && i <= 255)
575 surveillance_timeout = i;
576 }
577
578 return 1;
579 }
580 __setup("surveillance=", surveillance_setup);
581
rtasmsgs_setup(char * str)582 static int __init rtasmsgs_setup(char *str)
583 {
584 return (kstrtobool(str, &full_rtas_msgs) == 0);
585 }
586 __setup("rtasmsgs=", rtasmsgs_setup);
587