1 /*
2 * c 2001 PPC 64 Team, IBM Corp
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 * /dev/nvram driver for PPC64
10 *
11 * This perhaps should live in drivers/char
12 *
13 * TODO: Split the /dev/nvram part (that one can use
14 * drivers/char/generic_nvram.c) from the arch & partition
15 * parsing code.
16 */
17
18 #include <linux/module.h>
19
20 #include <linux/types.h>
21 #include <linux/errno.h>
22 #include <linux/fs.h>
23 #include <linux/miscdevice.h>
24 #include <linux/fcntl.h>
25 #include <linux/nvram.h>
26 #include <linux/init.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/kmsg_dump.h>
30 #include <linux/pstore.h>
31 #include <linux/zlib.h>
32 #include <asm/uaccess.h>
33 #include <asm/nvram.h>
34 #include <asm/rtas.h>
35 #include <asm/prom.h>
36 #include <asm/machdep.h>
37
38 #undef DEBUG_NVRAM
39
40 #define NVRAM_HEADER_LEN sizeof(struct nvram_header)
41 #define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
42
43 /* If change this size, then change the size of NVNAME_LEN */
44 struct nvram_header {
45 unsigned char signature;
46 unsigned char checksum;
47 unsigned short length;
48 /* Terminating null required only for names < 12 chars. */
49 char name[12];
50 };
51
52 struct nvram_partition {
53 struct list_head partition;
54 struct nvram_header header;
55 unsigned int index;
56 };
57
58 static LIST_HEAD(nvram_partitions);
59
60 #ifdef CONFIG_PPC_PSERIES
61 struct nvram_os_partition rtas_log_partition = {
62 .name = "ibm,rtas-log",
63 .req_size = 2079,
64 .min_size = 1055,
65 .index = -1,
66 .os_partition = true
67 };
68 #endif
69
70 struct nvram_os_partition oops_log_partition = {
71 .name = "lnx,oops-log",
72 .req_size = 4000,
73 .min_size = 2000,
74 .index = -1,
75 .os_partition = true
76 };
77
78 static const char *nvram_os_partitions[] = {
79 #ifdef CONFIG_PPC_PSERIES
80 "ibm,rtas-log",
81 #endif
82 "lnx,oops-log",
83 NULL
84 };
85
86 static void oops_to_nvram(struct kmsg_dumper *dumper,
87 enum kmsg_dump_reason reason);
88
89 static struct kmsg_dumper nvram_kmsg_dumper = {
90 .dump = oops_to_nvram
91 };
92
93 /*
94 * For capturing and compressing an oops or panic report...
95
96 * big_oops_buf[] holds the uncompressed text we're capturing.
97 *
98 * oops_buf[] holds the compressed text, preceded by a oops header.
99 * oops header has u16 holding the version of oops header (to differentiate
100 * between old and new format header) followed by u16 holding the length of
101 * the compressed* text (*Or uncompressed, if compression fails.) and u64
102 * holding the timestamp. oops_buf[] gets written to NVRAM.
103 *
104 * oops_log_info points to the header. oops_data points to the compressed text.
105 *
106 * +- oops_buf
107 * | +- oops_data
108 * v v
109 * +-----------+-----------+-----------+------------------------+
110 * | version | length | timestamp | text |
111 * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes) |
112 * +-----------+-----------+-----------+------------------------+
113 * ^
114 * +- oops_log_info
115 *
116 * We preallocate these buffers during init to avoid kmalloc during oops/panic.
117 */
118 static size_t big_oops_buf_sz;
119 static char *big_oops_buf, *oops_buf;
120 static char *oops_data;
121 static size_t oops_data_sz;
122
123 /* Compression parameters */
124 #define COMPR_LEVEL 6
125 #define WINDOW_BITS 12
126 #define MEM_LEVEL 4
127 static struct z_stream_s stream;
128
129 #ifdef CONFIG_PSTORE
130 #ifdef CONFIG_PPC_POWERNV
131 static struct nvram_os_partition skiboot_partition = {
132 .name = "ibm,skiboot",
133 .index = -1,
134 .os_partition = false
135 };
136 #endif
137
138 #ifdef CONFIG_PPC_PSERIES
139 static struct nvram_os_partition of_config_partition = {
140 .name = "of-config",
141 .index = -1,
142 .os_partition = false
143 };
144 #endif
145
146 static struct nvram_os_partition common_partition = {
147 .name = "common",
148 .index = -1,
149 .os_partition = false
150 };
151
152 static enum pstore_type_id nvram_type_ids[] = {
153 PSTORE_TYPE_DMESG,
154 PSTORE_TYPE_PPC_COMMON,
155 -1,
156 -1,
157 -1
158 };
159 static int read_type;
160 #endif
161
162 /* nvram_write_os_partition
163 *
164 * We need to buffer the error logs into nvram to ensure that we have
165 * the failure information to decode. If we have a severe error there
166 * is no way to guarantee that the OS or the machine is in a state to
167 * get back to user land and write the error to disk. For example if
168 * the SCSI device driver causes a Machine Check by writing to a bad
169 * IO address, there is no way of guaranteeing that the device driver
170 * is in any state that is would also be able to write the error data
171 * captured to disk, thus we buffer it in NVRAM for analysis on the
172 * next boot.
173 *
174 * In NVRAM the partition containing the error log buffer will looks like:
175 * Header (in bytes):
176 * +-----------+----------+--------+------------+------------------+
177 * | signature | checksum | length | name | data |
178 * |0 |1 |2 3|4 15|16 length-1|
179 * +-----------+----------+--------+------------+------------------+
180 *
181 * The 'data' section would look like (in bytes):
182 * +--------------+------------+-----------------------------------+
183 * | event_logged | sequence # | error log |
184 * |0 3|4 7|8 error_log_size-1|
185 * +--------------+------------+-----------------------------------+
186 *
187 * event_logged: 0 if event has not been logged to syslog, 1 if it has
188 * sequence #: The unique sequence # for each event. (until it wraps)
189 * error log: The error log from event_scan
190 */
nvram_write_os_partition(struct nvram_os_partition * part,char * buff,int length,unsigned int err_type,unsigned int error_log_cnt)191 int nvram_write_os_partition(struct nvram_os_partition *part,
192 char *buff, int length,
193 unsigned int err_type,
194 unsigned int error_log_cnt)
195 {
196 int rc;
197 loff_t tmp_index;
198 struct err_log_info info;
199
200 if (part->index == -1)
201 return -ESPIPE;
202
203 if (length > part->size)
204 length = part->size;
205
206 info.error_type = cpu_to_be32(err_type);
207 info.seq_num = cpu_to_be32(error_log_cnt);
208
209 tmp_index = part->index;
210
211 rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
212 &tmp_index);
213 if (rc <= 0) {
214 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
215 return rc;
216 }
217
218 rc = ppc_md.nvram_write(buff, length, &tmp_index);
219 if (rc <= 0) {
220 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
221 return rc;
222 }
223
224 return 0;
225 }
226
227 /* nvram_read_partition
228 *
229 * Reads nvram partition for at most 'length'
230 */
nvram_read_partition(struct nvram_os_partition * part,char * buff,int length,unsigned int * err_type,unsigned int * error_log_cnt)231 int nvram_read_partition(struct nvram_os_partition *part, char *buff,
232 int length, unsigned int *err_type,
233 unsigned int *error_log_cnt)
234 {
235 int rc;
236 loff_t tmp_index;
237 struct err_log_info info;
238
239 if (part->index == -1)
240 return -1;
241
242 if (length > part->size)
243 length = part->size;
244
245 tmp_index = part->index;
246
247 if (part->os_partition) {
248 rc = ppc_md.nvram_read((char *)&info,
249 sizeof(struct err_log_info),
250 &tmp_index);
251 if (rc <= 0) {
252 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
253 return rc;
254 }
255 }
256
257 rc = ppc_md.nvram_read(buff, length, &tmp_index);
258 if (rc <= 0) {
259 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
260 return rc;
261 }
262
263 if (part->os_partition) {
264 *error_log_cnt = be32_to_cpu(info.seq_num);
265 *err_type = be32_to_cpu(info.error_type);
266 }
267
268 return 0;
269 }
270
271 /* nvram_init_os_partition
272 *
273 * This sets up a partition with an "OS" signature.
274 *
275 * The general strategy is the following:
276 * 1.) If a partition with the indicated name already exists...
277 * - If it's large enough, use it.
278 * - Otherwise, recycle it and keep going.
279 * 2.) Search for a free partition that is large enough.
280 * 3.) If there's not a free partition large enough, recycle any obsolete
281 * OS partitions and try again.
282 * 4.) Will first try getting a chunk that will satisfy the requested size.
283 * 5.) If a chunk of the requested size cannot be allocated, then try finding
284 * a chunk that will satisfy the minum needed.
285 *
286 * Returns 0 on success, else -1.
287 */
nvram_init_os_partition(struct nvram_os_partition * part)288 int __init nvram_init_os_partition(struct nvram_os_partition *part)
289 {
290 loff_t p;
291 int size;
292
293 /* Look for ours */
294 p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
295
296 /* Found one but too small, remove it */
297 if (p && size < part->min_size) {
298 pr_info("nvram: Found too small %s partition,"
299 " removing it...\n", part->name);
300 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
301 p = 0;
302 }
303
304 /* Create one if we didn't find */
305 if (!p) {
306 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
307 part->req_size, part->min_size);
308 if (p == -ENOSPC) {
309 pr_info("nvram: No room to create %s partition, "
310 "deleting any obsolete OS partitions...\n",
311 part->name);
312 nvram_remove_partition(NULL, NVRAM_SIG_OS,
313 nvram_os_partitions);
314 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
315 part->req_size, part->min_size);
316 }
317 }
318
319 if (p <= 0) {
320 pr_err("nvram: Failed to find or create %s"
321 " partition, err %d\n", part->name, (int)p);
322 return -1;
323 }
324
325 part->index = p;
326 part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
327
328 return 0;
329 }
330
331 /* Derived from logfs_compress() */
nvram_compress(const void * in,void * out,size_t inlen,size_t outlen)332 static int nvram_compress(const void *in, void *out, size_t inlen,
333 size_t outlen)
334 {
335 int err, ret;
336
337 ret = -EIO;
338 err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
339 MEM_LEVEL, Z_DEFAULT_STRATEGY);
340 if (err != Z_OK)
341 goto error;
342
343 stream.next_in = in;
344 stream.avail_in = inlen;
345 stream.total_in = 0;
346 stream.next_out = out;
347 stream.avail_out = outlen;
348 stream.total_out = 0;
349
350 err = zlib_deflate(&stream, Z_FINISH);
351 if (err != Z_STREAM_END)
352 goto error;
353
354 err = zlib_deflateEnd(&stream);
355 if (err != Z_OK)
356 goto error;
357
358 if (stream.total_out >= stream.total_in)
359 goto error;
360
361 ret = stream.total_out;
362 error:
363 return ret;
364 }
365
366 /* Compress the text from big_oops_buf into oops_buf. */
zip_oops(size_t text_len)367 static int zip_oops(size_t text_len)
368 {
369 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
370 int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
371 oops_data_sz);
372 if (zipped_len < 0) {
373 pr_err("nvram: compression failed; returned %d\n", zipped_len);
374 pr_err("nvram: logging uncompressed oops/panic report\n");
375 return -1;
376 }
377 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
378 oops_hdr->report_length = cpu_to_be16(zipped_len);
379 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
380 return 0;
381 }
382
383 #ifdef CONFIG_PSTORE
nvram_pstore_open(struct pstore_info * psi)384 static int nvram_pstore_open(struct pstore_info *psi)
385 {
386 /* Reset the iterator to start reading partitions again */
387 read_type = -1;
388 return 0;
389 }
390
391 /**
392 * nvram_pstore_write - pstore write callback for nvram
393 * @type: Type of message logged
394 * @reason: reason behind dump (oops/panic)
395 * @id: identifier to indicate the write performed
396 * @part: pstore writes data to registered buffer in parts,
397 * part number will indicate the same.
398 * @count: Indicates oops count
399 * @compressed: Flag to indicate the log is compressed
400 * @size: number of bytes written to the registered buffer
401 * @psi: registered pstore_info structure
402 *
403 * Called by pstore_dump() when an oops or panic report is logged in the
404 * printk buffer.
405 * Returns 0 on successful write.
406 */
nvram_pstore_write(enum pstore_type_id type,enum kmsg_dump_reason reason,u64 * id,unsigned int part,int count,bool compressed,size_t size,struct pstore_info * psi)407 static int nvram_pstore_write(enum pstore_type_id type,
408 enum kmsg_dump_reason reason,
409 u64 *id, unsigned int part, int count,
410 bool compressed, size_t size,
411 struct pstore_info *psi)
412 {
413 int rc;
414 unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
415 struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
416
417 /* part 1 has the recent messages from printk buffer */
418 if (part > 1 || (type != PSTORE_TYPE_DMESG))
419 return -1;
420
421 if (clobbering_unread_rtas_event())
422 return -1;
423
424 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
425 oops_hdr->report_length = cpu_to_be16(size);
426 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
427
428 if (compressed)
429 err_type = ERR_TYPE_KERNEL_PANIC_GZ;
430
431 rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
432 (int) (sizeof(*oops_hdr) + size), err_type, count);
433
434 if (rc != 0)
435 return rc;
436
437 *id = part;
438 return 0;
439 }
440
441 /*
442 * Reads the oops/panic report, rtas, of-config and common partition.
443 * Returns the length of the data we read from each partition.
444 * Returns 0 if we've been called before.
445 */
nvram_pstore_read(u64 * id,enum pstore_type_id * type,int * count,struct timespec * time,char ** buf,bool * compressed,struct pstore_info * psi)446 static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
447 int *count, struct timespec *time, char **buf,
448 bool *compressed, struct pstore_info *psi)
449 {
450 struct oops_log_info *oops_hdr;
451 unsigned int err_type, id_no, size = 0;
452 struct nvram_os_partition *part = NULL;
453 char *buff = NULL;
454 int sig = 0;
455 loff_t p;
456
457 read_type++;
458
459 switch (nvram_type_ids[read_type]) {
460 case PSTORE_TYPE_DMESG:
461 part = &oops_log_partition;
462 *type = PSTORE_TYPE_DMESG;
463 break;
464 case PSTORE_TYPE_PPC_COMMON:
465 sig = NVRAM_SIG_SYS;
466 part = &common_partition;
467 *type = PSTORE_TYPE_PPC_COMMON;
468 *id = PSTORE_TYPE_PPC_COMMON;
469 time->tv_sec = 0;
470 time->tv_nsec = 0;
471 break;
472 #ifdef CONFIG_PPC_PSERIES
473 case PSTORE_TYPE_PPC_RTAS:
474 part = &rtas_log_partition;
475 *type = PSTORE_TYPE_PPC_RTAS;
476 time->tv_sec = last_rtas_event;
477 time->tv_nsec = 0;
478 break;
479 case PSTORE_TYPE_PPC_OF:
480 sig = NVRAM_SIG_OF;
481 part = &of_config_partition;
482 *type = PSTORE_TYPE_PPC_OF;
483 *id = PSTORE_TYPE_PPC_OF;
484 time->tv_sec = 0;
485 time->tv_nsec = 0;
486 break;
487 #endif
488 #ifdef CONFIG_PPC_POWERNV
489 case PSTORE_TYPE_PPC_OPAL:
490 sig = NVRAM_SIG_FW;
491 part = &skiboot_partition;
492 *type = PSTORE_TYPE_PPC_OPAL;
493 *id = PSTORE_TYPE_PPC_OPAL;
494 time->tv_sec = 0;
495 time->tv_nsec = 0;
496 break;
497 #endif
498 default:
499 return 0;
500 }
501
502 if (!part->os_partition) {
503 p = nvram_find_partition(part->name, sig, &size);
504 if (p <= 0) {
505 pr_err("nvram: Failed to find partition %s, "
506 "err %d\n", part->name, (int)p);
507 return 0;
508 }
509 part->index = p;
510 part->size = size;
511 }
512
513 buff = kmalloc(part->size, GFP_KERNEL);
514
515 if (!buff)
516 return -ENOMEM;
517
518 if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
519 kfree(buff);
520 return 0;
521 }
522
523 *count = 0;
524
525 if (part->os_partition)
526 *id = id_no;
527
528 if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
529 size_t length, hdr_size;
530
531 oops_hdr = (struct oops_log_info *)buff;
532 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
533 /* Old format oops header had 2-byte record size */
534 hdr_size = sizeof(u16);
535 length = be16_to_cpu(oops_hdr->version);
536 time->tv_sec = 0;
537 time->tv_nsec = 0;
538 } else {
539 hdr_size = sizeof(*oops_hdr);
540 length = be16_to_cpu(oops_hdr->report_length);
541 time->tv_sec = be64_to_cpu(oops_hdr->timestamp);
542 time->tv_nsec = 0;
543 }
544 *buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
545 if (*buf == NULL)
546 return -ENOMEM;
547 kfree(buff);
548
549 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
550 *compressed = true;
551 else
552 *compressed = false;
553 return length;
554 }
555
556 *buf = buff;
557 return part->size;
558 }
559
560 static struct pstore_info nvram_pstore_info = {
561 .owner = THIS_MODULE,
562 .name = "nvram",
563 .open = nvram_pstore_open,
564 .read = nvram_pstore_read,
565 .write = nvram_pstore_write,
566 };
567
nvram_pstore_init(void)568 static int nvram_pstore_init(void)
569 {
570 int rc = 0;
571
572 if (machine_is(pseries)) {
573 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
574 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
575 } else
576 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
577
578 nvram_pstore_info.buf = oops_data;
579 nvram_pstore_info.bufsize = oops_data_sz;
580
581 spin_lock_init(&nvram_pstore_info.buf_lock);
582
583 rc = pstore_register(&nvram_pstore_info);
584 if (rc && (rc != -EPERM))
585 /* Print error only when pstore.backend == nvram */
586 pr_err("nvram: pstore_register() failed, returned %d. "
587 "Defaults to kmsg_dump\n", rc);
588
589 return rc;
590 }
591 #else
nvram_pstore_init(void)592 static int nvram_pstore_init(void)
593 {
594 return -1;
595 }
596 #endif
597
nvram_init_oops_partition(int rtas_partition_exists)598 void __init nvram_init_oops_partition(int rtas_partition_exists)
599 {
600 int rc;
601
602 rc = nvram_init_os_partition(&oops_log_partition);
603 if (rc != 0) {
604 #ifdef CONFIG_PPC_PSERIES
605 if (!rtas_partition_exists) {
606 pr_err("nvram: Failed to initialize oops partition!");
607 return;
608 }
609 pr_notice("nvram: Using %s partition to log both"
610 " RTAS errors and oops/panic reports\n",
611 rtas_log_partition.name);
612 memcpy(&oops_log_partition, &rtas_log_partition,
613 sizeof(rtas_log_partition));
614 #else
615 pr_err("nvram: Failed to initialize oops partition!");
616 return;
617 #endif
618 }
619 oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
620 if (!oops_buf) {
621 pr_err("nvram: No memory for %s partition\n",
622 oops_log_partition.name);
623 return;
624 }
625 oops_data = oops_buf + sizeof(struct oops_log_info);
626 oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
627
628 rc = nvram_pstore_init();
629
630 if (!rc)
631 return;
632
633 /*
634 * Figure compression (preceded by elimination of each line's <n>
635 * severity prefix) will reduce the oops/panic report to at most
636 * 45% of its original size.
637 */
638 big_oops_buf_sz = (oops_data_sz * 100) / 45;
639 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
640 if (big_oops_buf) {
641 stream.workspace = kmalloc(zlib_deflate_workspacesize(
642 WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
643 if (!stream.workspace) {
644 pr_err("nvram: No memory for compression workspace; "
645 "skipping compression of %s partition data\n",
646 oops_log_partition.name);
647 kfree(big_oops_buf);
648 big_oops_buf = NULL;
649 }
650 } else {
651 pr_err("No memory for uncompressed %s data; "
652 "skipping compression\n", oops_log_partition.name);
653 stream.workspace = NULL;
654 }
655
656 rc = kmsg_dump_register(&nvram_kmsg_dumper);
657 if (rc != 0) {
658 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
659 kfree(oops_buf);
660 kfree(big_oops_buf);
661 kfree(stream.workspace);
662 }
663 }
664
665 /*
666 * This is our kmsg_dump callback, called after an oops or panic report
667 * has been written to the printk buffer. We want to capture as much
668 * of the printk buffer as possible. First, capture as much as we can
669 * that we think will compress sufficiently to fit in the lnx,oops-log
670 * partition. If that's too much, go back and capture uncompressed text.
671 */
oops_to_nvram(struct kmsg_dumper * dumper,enum kmsg_dump_reason reason)672 static void oops_to_nvram(struct kmsg_dumper *dumper,
673 enum kmsg_dump_reason reason)
674 {
675 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
676 static unsigned int oops_count = 0;
677 static bool panicking = false;
678 static DEFINE_SPINLOCK(lock);
679 unsigned long flags;
680 size_t text_len;
681 unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
682 int rc = -1;
683
684 switch (reason) {
685 case KMSG_DUMP_RESTART:
686 case KMSG_DUMP_HALT:
687 case KMSG_DUMP_POWEROFF:
688 /* These are almost always orderly shutdowns. */
689 return;
690 case KMSG_DUMP_OOPS:
691 break;
692 case KMSG_DUMP_PANIC:
693 panicking = true;
694 break;
695 case KMSG_DUMP_EMERG:
696 if (panicking)
697 /* Panic report already captured. */
698 return;
699 break;
700 default:
701 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
702 __func__, (int) reason);
703 return;
704 }
705
706 if (clobbering_unread_rtas_event())
707 return;
708
709 if (!spin_trylock_irqsave(&lock, flags))
710 return;
711
712 if (big_oops_buf) {
713 kmsg_dump_get_buffer(dumper, false,
714 big_oops_buf, big_oops_buf_sz, &text_len);
715 rc = zip_oops(text_len);
716 }
717 if (rc != 0) {
718 kmsg_dump_rewind(dumper);
719 kmsg_dump_get_buffer(dumper, false,
720 oops_data, oops_data_sz, &text_len);
721 err_type = ERR_TYPE_KERNEL_PANIC;
722 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
723 oops_hdr->report_length = cpu_to_be16(text_len);
724 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
725 }
726
727 (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
728 (int) (sizeof(*oops_hdr) + text_len), err_type,
729 ++oops_count);
730
731 spin_unlock_irqrestore(&lock, flags);
732 }
733
dev_nvram_llseek(struct file * file,loff_t offset,int origin)734 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
735 {
736 int size;
737
738 if (ppc_md.nvram_size == NULL)
739 return -ENODEV;
740 size = ppc_md.nvram_size();
741
742 switch (origin) {
743 case 1:
744 offset += file->f_pos;
745 break;
746 case 2:
747 offset += size;
748 break;
749 }
750 if (offset < 0)
751 return -EINVAL;
752 file->f_pos = offset;
753 return file->f_pos;
754 }
755
756
dev_nvram_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)757 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
758 size_t count, loff_t *ppos)
759 {
760 ssize_t ret;
761 char *tmp = NULL;
762 ssize_t size;
763
764 if (!ppc_md.nvram_size) {
765 ret = -ENODEV;
766 goto out;
767 }
768
769 size = ppc_md.nvram_size();
770 if (size < 0) {
771 ret = size;
772 goto out;
773 }
774
775 if (*ppos >= size) {
776 ret = 0;
777 goto out;
778 }
779
780 count = min_t(size_t, count, size - *ppos);
781 count = min(count, PAGE_SIZE);
782
783 tmp = kmalloc(count, GFP_KERNEL);
784 if (!tmp) {
785 ret = -ENOMEM;
786 goto out;
787 }
788
789 ret = ppc_md.nvram_read(tmp, count, ppos);
790 if (ret <= 0)
791 goto out;
792
793 if (copy_to_user(buf, tmp, ret))
794 ret = -EFAULT;
795
796 out:
797 kfree(tmp);
798 return ret;
799
800 }
801
dev_nvram_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)802 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
803 size_t count, loff_t *ppos)
804 {
805 ssize_t ret;
806 char *tmp = NULL;
807 ssize_t size;
808
809 ret = -ENODEV;
810 if (!ppc_md.nvram_size)
811 goto out;
812
813 ret = 0;
814 size = ppc_md.nvram_size();
815 if (*ppos >= size || size < 0)
816 goto out;
817
818 count = min_t(size_t, count, size - *ppos);
819 count = min(count, PAGE_SIZE);
820
821 ret = -ENOMEM;
822 tmp = kmalloc(count, GFP_KERNEL);
823 if (!tmp)
824 goto out;
825
826 ret = -EFAULT;
827 if (copy_from_user(tmp, buf, count))
828 goto out;
829
830 ret = ppc_md.nvram_write(tmp, count, ppos);
831
832 out:
833 kfree(tmp);
834 return ret;
835
836 }
837
dev_nvram_ioctl(struct file * file,unsigned int cmd,unsigned long arg)838 static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
839 unsigned long arg)
840 {
841 switch(cmd) {
842 #ifdef CONFIG_PPC_PMAC
843 case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
844 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
845 case IOC_NVRAM_GET_OFFSET: {
846 int part, offset;
847
848 if (!machine_is(powermac))
849 return -EINVAL;
850 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
851 return -EFAULT;
852 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
853 return -EINVAL;
854 offset = pmac_get_partition(part);
855 if (offset < 0)
856 return offset;
857 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
858 return -EFAULT;
859 return 0;
860 }
861 #endif /* CONFIG_PPC_PMAC */
862 default:
863 return -EINVAL;
864 }
865 }
866
867 const struct file_operations nvram_fops = {
868 .owner = THIS_MODULE,
869 .llseek = dev_nvram_llseek,
870 .read = dev_nvram_read,
871 .write = dev_nvram_write,
872 .unlocked_ioctl = dev_nvram_ioctl,
873 };
874
875 static struct miscdevice nvram_dev = {
876 NVRAM_MINOR,
877 "nvram",
878 &nvram_fops
879 };
880
881
882 #ifdef DEBUG_NVRAM
nvram_print_partitions(char * label)883 static void __init nvram_print_partitions(char * label)
884 {
885 struct nvram_partition * tmp_part;
886
887 printk(KERN_WARNING "--------%s---------\n", label);
888 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
889 list_for_each_entry(tmp_part, &nvram_partitions, partition) {
890 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12.12s\n",
891 tmp_part->index, tmp_part->header.signature,
892 tmp_part->header.checksum, tmp_part->header.length,
893 tmp_part->header.name);
894 }
895 }
896 #endif
897
898
nvram_write_header(struct nvram_partition * part)899 static int __init nvram_write_header(struct nvram_partition * part)
900 {
901 loff_t tmp_index;
902 int rc;
903 struct nvram_header phead;
904
905 memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
906 phead.length = cpu_to_be16(phead.length);
907
908 tmp_index = part->index;
909 rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
910
911 return rc;
912 }
913
914
nvram_checksum(struct nvram_header * p)915 static unsigned char __init nvram_checksum(struct nvram_header *p)
916 {
917 unsigned int c_sum, c_sum2;
918 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
919 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
920
921 /* The sum may have spilled into the 3rd byte. Fold it back. */
922 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
923 /* The sum cannot exceed 2 bytes. Fold it into a checksum */
924 c_sum2 = (c_sum >> 8) + (c_sum << 8);
925 c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
926 return c_sum;
927 }
928
929 /*
930 * Per the criteria passed via nvram_remove_partition(), should this
931 * partition be removed? 1=remove, 0=keep
932 */
nvram_can_remove_partition(struct nvram_partition * part,const char * name,int sig,const char * exceptions[])933 static int nvram_can_remove_partition(struct nvram_partition *part,
934 const char *name, int sig, const char *exceptions[])
935 {
936 if (part->header.signature != sig)
937 return 0;
938 if (name) {
939 if (strncmp(name, part->header.name, 12))
940 return 0;
941 } else if (exceptions) {
942 const char **except;
943 for (except = exceptions; *except; except++) {
944 if (!strncmp(*except, part->header.name, 12))
945 return 0;
946 }
947 }
948 return 1;
949 }
950
951 /**
952 * nvram_remove_partition - Remove one or more partitions in nvram
953 * @name: name of the partition to remove, or NULL for a
954 * signature only match
955 * @sig: signature of the partition(s) to remove
956 * @exceptions: When removing all partitions with a matching signature,
957 * leave these alone.
958 */
959
nvram_remove_partition(const char * name,int sig,const char * exceptions[])960 int __init nvram_remove_partition(const char *name, int sig,
961 const char *exceptions[])
962 {
963 struct nvram_partition *part, *prev, *tmp;
964 int rc;
965
966 list_for_each_entry(part, &nvram_partitions, partition) {
967 if (!nvram_can_remove_partition(part, name, sig, exceptions))
968 continue;
969
970 /* Make partition a free partition */
971 part->header.signature = NVRAM_SIG_FREE;
972 memset(part->header.name, 'w', 12);
973 part->header.checksum = nvram_checksum(&part->header);
974 rc = nvram_write_header(part);
975 if (rc <= 0) {
976 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
977 return rc;
978 }
979 }
980
981 /* Merge contiguous ones */
982 prev = NULL;
983 list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
984 if (part->header.signature != NVRAM_SIG_FREE) {
985 prev = NULL;
986 continue;
987 }
988 if (prev) {
989 prev->header.length += part->header.length;
990 prev->header.checksum = nvram_checksum(&prev->header);
991 rc = nvram_write_header(prev);
992 if (rc <= 0) {
993 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
994 return rc;
995 }
996 list_del(&part->partition);
997 kfree(part);
998 } else
999 prev = part;
1000 }
1001
1002 return 0;
1003 }
1004
1005 /**
1006 * nvram_create_partition - Create a partition in nvram
1007 * @name: name of the partition to create
1008 * @sig: signature of the partition to create
1009 * @req_size: size of data to allocate in bytes
1010 * @min_size: minimum acceptable size (0 means req_size)
1011 *
1012 * Returns a negative error code or a positive nvram index
1013 * of the beginning of the data area of the newly created
1014 * partition. If you provided a min_size smaller than req_size
1015 * you need to query for the actual size yourself after the
1016 * call using nvram_partition_get_size().
1017 */
nvram_create_partition(const char * name,int sig,int req_size,int min_size)1018 loff_t __init nvram_create_partition(const char *name, int sig,
1019 int req_size, int min_size)
1020 {
1021 struct nvram_partition *part;
1022 struct nvram_partition *new_part;
1023 struct nvram_partition *free_part = NULL;
1024 static char nv_init_vals[16];
1025 loff_t tmp_index;
1026 long size = 0;
1027 int rc;
1028
1029 /* Convert sizes from bytes to blocks */
1030 req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
1031 min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
1032
1033 /* If no minimum size specified, make it the same as the
1034 * requested size
1035 */
1036 if (min_size == 0)
1037 min_size = req_size;
1038 if (min_size > req_size)
1039 return -EINVAL;
1040
1041 /* Now add one block to each for the header */
1042 req_size += 1;
1043 min_size += 1;
1044
1045 /* Find a free partition that will give us the maximum needed size
1046 If can't find one that will give us the minimum size needed */
1047 list_for_each_entry(part, &nvram_partitions, partition) {
1048 if (part->header.signature != NVRAM_SIG_FREE)
1049 continue;
1050
1051 if (part->header.length >= req_size) {
1052 size = req_size;
1053 free_part = part;
1054 break;
1055 }
1056 if (part->header.length > size &&
1057 part->header.length >= min_size) {
1058 size = part->header.length;
1059 free_part = part;
1060 }
1061 }
1062 if (!size)
1063 return -ENOSPC;
1064
1065 /* Create our OS partition */
1066 new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1067 if (!new_part) {
1068 pr_err("%s: kmalloc failed\n", __func__);
1069 return -ENOMEM;
1070 }
1071
1072 new_part->index = free_part->index;
1073 new_part->header.signature = sig;
1074 new_part->header.length = size;
1075 strncpy(new_part->header.name, name, 12);
1076 new_part->header.checksum = nvram_checksum(&new_part->header);
1077
1078 rc = nvram_write_header(new_part);
1079 if (rc <= 0) {
1080 pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
1081 kfree(new_part);
1082 return rc;
1083 }
1084 list_add_tail(&new_part->partition, &free_part->partition);
1085
1086 /* Adjust or remove the partition we stole the space from */
1087 if (free_part->header.length > size) {
1088 free_part->index += size * NVRAM_BLOCK_LEN;
1089 free_part->header.length -= size;
1090 free_part->header.checksum = nvram_checksum(&free_part->header);
1091 rc = nvram_write_header(free_part);
1092 if (rc <= 0) {
1093 pr_err("%s: nvram_write_header failed (%d)\n",
1094 __func__, rc);
1095 return rc;
1096 }
1097 } else {
1098 list_del(&free_part->partition);
1099 kfree(free_part);
1100 }
1101
1102 /* Clear the new partition */
1103 for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
1104 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
1105 tmp_index += NVRAM_BLOCK_LEN) {
1106 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
1107 if (rc <= 0) {
1108 pr_err("%s: nvram_write failed (%d)\n",
1109 __func__, rc);
1110 return rc;
1111 }
1112 }
1113
1114 return new_part->index + NVRAM_HEADER_LEN;
1115 }
1116
1117 /**
1118 * nvram_get_partition_size - Get the data size of an nvram partition
1119 * @data_index: This is the offset of the start of the data of
1120 * the partition. The same value that is returned by
1121 * nvram_create_partition().
1122 */
nvram_get_partition_size(loff_t data_index)1123 int nvram_get_partition_size(loff_t data_index)
1124 {
1125 struct nvram_partition *part;
1126
1127 list_for_each_entry(part, &nvram_partitions, partition) {
1128 if (part->index + NVRAM_HEADER_LEN == data_index)
1129 return (part->header.length - 1) * NVRAM_BLOCK_LEN;
1130 }
1131 return -1;
1132 }
1133
1134
1135 /**
1136 * nvram_find_partition - Find an nvram partition by signature and name
1137 * @name: Name of the partition or NULL for any name
1138 * @sig: Signature to test against
1139 * @out_size: if non-NULL, returns the size of the data part of the partition
1140 */
nvram_find_partition(const char * name,int sig,int * out_size)1141 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
1142 {
1143 struct nvram_partition *p;
1144
1145 list_for_each_entry(p, &nvram_partitions, partition) {
1146 if (p->header.signature == sig &&
1147 (!name || !strncmp(p->header.name, name, 12))) {
1148 if (out_size)
1149 *out_size = (p->header.length - 1) *
1150 NVRAM_BLOCK_LEN;
1151 return p->index + NVRAM_HEADER_LEN;
1152 }
1153 }
1154 return 0;
1155 }
1156
nvram_scan_partitions(void)1157 int __init nvram_scan_partitions(void)
1158 {
1159 loff_t cur_index = 0;
1160 struct nvram_header phead;
1161 struct nvram_partition * tmp_part;
1162 unsigned char c_sum;
1163 char * header;
1164 int total_size;
1165 int err;
1166
1167 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1168 return -ENODEV;
1169 total_size = ppc_md.nvram_size();
1170
1171 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1172 if (!header) {
1173 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
1174 return -ENOMEM;
1175 }
1176
1177 while (cur_index < total_size) {
1178
1179 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
1180 if (err != NVRAM_HEADER_LEN) {
1181 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
1182 "nvram partitions\n");
1183 goto out;
1184 }
1185
1186 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
1187
1188 memcpy(&phead, header, NVRAM_HEADER_LEN);
1189
1190 phead.length = be16_to_cpu(phead.length);
1191
1192 err = 0;
1193 c_sum = nvram_checksum(&phead);
1194 if (c_sum != phead.checksum) {
1195 printk(KERN_WARNING "WARNING: nvram partition checksum"
1196 " was %02x, should be %02x!\n",
1197 phead.checksum, c_sum);
1198 printk(KERN_WARNING "Terminating nvram partition scan\n");
1199 goto out;
1200 }
1201 if (!phead.length) {
1202 printk(KERN_WARNING "WARNING: nvram corruption "
1203 "detected: 0-length partition\n");
1204 goto out;
1205 }
1206 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
1207 err = -ENOMEM;
1208 if (!tmp_part) {
1209 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
1210 goto out;
1211 }
1212
1213 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
1214 tmp_part->index = cur_index;
1215 list_add_tail(&tmp_part->partition, &nvram_partitions);
1216
1217 cur_index += phead.length * NVRAM_BLOCK_LEN;
1218 }
1219 err = 0;
1220
1221 #ifdef DEBUG_NVRAM
1222 nvram_print_partitions("NVRAM Partitions");
1223 #endif
1224
1225 out:
1226 kfree(header);
1227 return err;
1228 }
1229
nvram_init(void)1230 static int __init nvram_init(void)
1231 {
1232 int rc;
1233
1234 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
1235
1236 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1237 return -ENODEV;
1238
1239 rc = misc_register(&nvram_dev);
1240 if (rc != 0) {
1241 printk(KERN_ERR "nvram_init: failed to register device\n");
1242 return rc;
1243 }
1244
1245 return rc;
1246 }
1247
nvram_cleanup(void)1248 static void __exit nvram_cleanup(void)
1249 {
1250 misc_deregister( &nvram_dev );
1251 }
1252
1253 module_init(nvram_init);
1254 module_exit(nvram_cleanup);
1255 MODULE_LICENSE("GPL");
1256