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