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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * c 2001 PPC 64 Team, IBM Corp
4 *
5 * /dev/nvram driver for PPC64
6 */
7
8#include <linux/types.h>
9#include <linux/errno.h>
10#include <linux/fs.h>
11#include <linux/miscdevice.h>
12#include <linux/fcntl.h>
13#include <linux/nvram.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17#include <linux/kmsg_dump.h>
18#include <linux/pagemap.h>
19#include <linux/pstore.h>
20#include <linux/zlib.h>
21#include <linux/uaccess.h>
22#include <linux/of.h>
23#include <asm/nvram.h>
24#include <asm/rtas.h>
25#include <asm/machdep.h>
26
27#undef DEBUG_NVRAM
28
29#define NVRAM_HEADER_LEN sizeof(struct nvram_header)
30#define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
31
32/* If change this size, then change the size of NVNAME_LEN */
33struct nvram_header {
34 unsigned char signature;
35 unsigned char checksum;
36 unsigned short length;
37 /* Terminating null required only for names < 12 chars. */
38 char name[12];
39};
40
41struct nvram_partition {
42 struct list_head partition;
43 struct nvram_header header;
44 unsigned int index;
45};
46
47static LIST_HEAD(nvram_partitions);
48
49#ifdef CONFIG_PPC_PSERIES
50struct nvram_os_partition rtas_log_partition = {
51 .name = "ibm,rtas-log",
52 .req_size = 2079,
53 .min_size = 1055,
54 .index = -1,
55 .os_partition = true
56};
57#endif
58
59struct nvram_os_partition oops_log_partition = {
60 .name = "lnx,oops-log",
61 .req_size = 4000,
62 .min_size = 2000,
63 .index = -1,
64 .os_partition = true
65};
66
67static const char *nvram_os_partitions[] = {
68#ifdef CONFIG_PPC_PSERIES
69 "ibm,rtas-log",
70#endif
71 "lnx,oops-log",
72 NULL
73};
74
75static void oops_to_nvram(struct kmsg_dumper *dumper,
76 struct kmsg_dump_detail *detail);
77
78static struct kmsg_dumper nvram_kmsg_dumper = {
79 .dump = oops_to_nvram
80};
81
82/*
83 * For capturing and compressing an oops or panic report...
84
85 * big_oops_buf[] holds the uncompressed text we're capturing.
86 *
87 * oops_buf[] holds the compressed text, preceded by a oops header.
88 * oops header has u16 holding the version of oops header (to differentiate
89 * between old and new format header) followed by u16 holding the length of
90 * the compressed* text (*Or uncompressed, if compression fails.) and u64
91 * holding the timestamp. oops_buf[] gets written to NVRAM.
92 *
93 * oops_log_info points to the header. oops_data points to the compressed text.
94 *
95 * +- oops_buf
96 * | +- oops_data
97 * v v
98 * +-----------+-----------+-----------+------------------------+
99 * | version | length | timestamp | text |
100 * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes) |
101 * +-----------+-----------+-----------+------------------------+
102 * ^
103 * +- oops_log_info
104 *
105 * We preallocate these buffers during init to avoid kmalloc during oops/panic.
106 */
107static size_t big_oops_buf_sz;
108static char *big_oops_buf, *oops_buf;
109static char *oops_data;
110static size_t oops_data_sz;
111
112/* Compression parameters */
113#define COMPR_LEVEL 6
114#define WINDOW_BITS 12
115#define MEM_LEVEL 4
116static struct z_stream_s stream;
117
118#ifdef CONFIG_PSTORE
119#ifdef CONFIG_PPC_POWERNV
120static struct nvram_os_partition skiboot_partition = {
121 .name = "ibm,skiboot",
122 .index = -1,
123 .os_partition = false
124};
125#endif
126
127#ifdef CONFIG_PPC_PSERIES
128static struct nvram_os_partition of_config_partition = {
129 .name = "of-config",
130 .index = -1,
131 .os_partition = false
132};
133#endif
134
135static struct nvram_os_partition common_partition = {
136 .name = "common",
137 .index = -1,
138 .os_partition = false
139};
140
141static enum pstore_type_id nvram_type_ids[] = {
142 PSTORE_TYPE_DMESG,
143 PSTORE_TYPE_PPC_COMMON,
144 -1,
145 -1,
146 -1
147};
148static int read_type;
149#endif
150
151/* nvram_write_os_partition
152 *
153 * We need to buffer the error logs into nvram to ensure that we have
154 * the failure information to decode. If we have a severe error there
155 * is no way to guarantee that the OS or the machine is in a state to
156 * get back to user land and write the error to disk. For example if
157 * the SCSI device driver causes a Machine Check by writing to a bad
158 * IO address, there is no way of guaranteeing that the device driver
159 * is in any state that is would also be able to write the error data
160 * captured to disk, thus we buffer it in NVRAM for analysis on the
161 * next boot.
162 *
163 * In NVRAM the partition containing the error log buffer will looks like:
164 * Header (in bytes):
165 * +-----------+----------+--------+------------+------------------+
166 * | signature | checksum | length | name | data |
167 * |0 |1 |2 3|4 15|16 length-1|
168 * +-----------+----------+--------+------------+------------------+
169 *
170 * The 'data' section would look like (in bytes):
171 * +--------------+------------+-----------------------------------+
172 * | event_logged | sequence # | error log |
173 * |0 3|4 7|8 error_log_size-1|
174 * +--------------+------------+-----------------------------------+
175 *
176 * event_logged: 0 if event has not been logged to syslog, 1 if it has
177 * sequence #: The unique sequence # for each event. (until it wraps)
178 * error log: The error log from event_scan
179 */
180int nvram_write_os_partition(struct nvram_os_partition *part,
181 char *buff, int length,
182 unsigned int err_type,
183 unsigned int error_log_cnt)
184{
185 int rc;
186 loff_t tmp_index;
187 struct err_log_info info;
188
189 if (part->index == -1)
190 return -ESPIPE;
191
192 if (length > part->size)
193 length = part->size;
194
195 info.error_type = cpu_to_be32(err_type);
196 info.seq_num = cpu_to_be32(error_log_cnt);
197
198 tmp_index = part->index;
199
200 rc = ppc_md.nvram_write((char *)&info, sizeof(info), &tmp_index);
201 if (rc <= 0) {
202 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
203 return rc;
204 }
205
206 rc = ppc_md.nvram_write(buff, length, &tmp_index);
207 if (rc <= 0) {
208 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
209 return rc;
210 }
211
212 return 0;
213}
214
215/* nvram_read_partition
216 *
217 * Reads nvram partition for at most 'length'
218 */
219int nvram_read_partition(struct nvram_os_partition *part, char *buff,
220 int length, unsigned int *err_type,
221 unsigned int *error_log_cnt)
222{
223 int rc;
224 loff_t tmp_index;
225 struct err_log_info info;
226
227 if (part->index == -1)
228 return -1;
229
230 if (length > part->size)
231 length = part->size;
232
233 tmp_index = part->index;
234
235 if (part->os_partition) {
236 rc = ppc_md.nvram_read((char *)&info, sizeof(info), &tmp_index);
237 if (rc <= 0) {
238 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
239 return rc;
240 }
241 }
242
243 rc = ppc_md.nvram_read(buff, length, &tmp_index);
244 if (rc <= 0) {
245 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
246 return rc;
247 }
248
249 if (part->os_partition) {
250 *error_log_cnt = be32_to_cpu(info.seq_num);
251 *err_type = be32_to_cpu(info.error_type);
252 }
253
254 return 0;
255}
256
257/* nvram_init_os_partition
258 *
259 * This sets up a partition with an "OS" signature.
260 *
261 * The general strategy is the following:
262 * 1.) If a partition with the indicated name already exists...
263 * - If it's large enough, use it.
264 * - Otherwise, recycle it and keep going.
265 * 2.) Search for a free partition that is large enough.
266 * 3.) If there's not a free partition large enough, recycle any obsolete
267 * OS partitions and try again.
268 * 4.) Will first try getting a chunk that will satisfy the requested size.
269 * 5.) If a chunk of the requested size cannot be allocated, then try finding
270 * a chunk that will satisfy the minum needed.
271 *
272 * Returns 0 on success, else -1.
273 */
274int __init nvram_init_os_partition(struct nvram_os_partition *part)
275{
276 loff_t p;
277 int size;
278
279 /* Look for ours */
280 p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
281
282 /* Found one but too small, remove it */
283 if (p && size < part->min_size) {
284 pr_info("nvram: Found too small %s partition,"
285 " removing it...\n", part->name);
286 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
287 p = 0;
288 }
289
290 /* Create one if we didn't find */
291 if (!p) {
292 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
293 part->req_size, part->min_size);
294 if (p == -ENOSPC) {
295 pr_info("nvram: No room to create %s partition, "
296 "deleting any obsolete OS partitions...\n",
297 part->name);
298 nvram_remove_partition(NULL, NVRAM_SIG_OS,
299 nvram_os_partitions);
300 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
301 part->req_size, part->min_size);
302 }
303 }
304
305 if (p <= 0) {
306 pr_err("nvram: Failed to find or create %s"
307 " partition, err %d\n", part->name, (int)p);
308 return -1;
309 }
310
311 part->index = p;
312 part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
313
314 return 0;
315}
316
317/* Derived from logfs_compress() */
318static int nvram_compress(const void *in, void *out, size_t inlen,
319 size_t outlen)
320{
321 int err, ret;
322
323 ret = -EIO;
324 err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
325 MEM_LEVEL, Z_DEFAULT_STRATEGY);
326 if (err != Z_OK)
327 goto error;
328
329 stream.next_in = in;
330 stream.avail_in = inlen;
331 stream.total_in = 0;
332 stream.next_out = out;
333 stream.avail_out = outlen;
334 stream.total_out = 0;
335
336 err = zlib_deflate(&stream, Z_FINISH);
337 if (err != Z_STREAM_END)
338 goto error;
339
340 err = zlib_deflateEnd(&stream);
341 if (err != Z_OK)
342 goto error;
343
344 if (stream.total_out >= stream.total_in)
345 goto error;
346
347 ret = stream.total_out;
348error:
349 return ret;
350}
351
352/* Compress the text from big_oops_buf into oops_buf. */
353static int zip_oops(size_t text_len)
354{
355 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
356 int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
357 oops_data_sz);
358 if (zipped_len < 0) {
359 pr_err("nvram: compression failed; returned %d\n", zipped_len);
360 pr_err("nvram: logging uncompressed oops/panic report\n");
361 return -1;
362 }
363 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
364 oops_hdr->report_length = cpu_to_be16(zipped_len);
365 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
366 return 0;
367}
368
369#ifdef CONFIG_PSTORE
370static int nvram_pstore_open(struct pstore_info *psi)
371{
372 /* Reset the iterator to start reading partitions again */
373 read_type = -1;
374 return 0;
375}
376
377/**
378 * nvram_pstore_write - pstore write callback for nvram
379 * @record: pstore record to write, with @id to be set
380 *
381 * Called by pstore_dump() when an oops or panic report is logged in the
382 * printk buffer.
383 * Returns 0 on successful write.
384 */
385static int nvram_pstore_write(struct pstore_record *record)
386{
387 int rc;
388 unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
389 struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
390
391 /* part 1 has the recent messages from printk buffer */
392 if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG))
393 return -1;
394
395 if (clobbering_unread_rtas_event())
396 return -1;
397
398 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
399 oops_hdr->report_length = cpu_to_be16(record->size);
400 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
401
402 if (record->compressed)
403 err_type = ERR_TYPE_KERNEL_PANIC_GZ;
404
405 rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
406 (int) (sizeof(*oops_hdr) + record->size), err_type,
407 record->count);
408
409 if (rc != 0)
410 return rc;
411
412 record->id = record->part;
413 return 0;
414}
415
416/*
417 * Reads the oops/panic report, rtas, of-config and common partition.
418 * Returns the length of the data we read from each partition.
419 * Returns 0 if we've been called before.
420 */
421static ssize_t nvram_pstore_read(struct pstore_record *record)
422{
423 struct oops_log_info *oops_hdr;
424 unsigned int err_type, id_no, size = 0;
425 struct nvram_os_partition *part = NULL;
426 char *buff = NULL;
427 int sig = 0;
428 loff_t p;
429
430 read_type++;
431
432 switch (nvram_type_ids[read_type]) {
433 case PSTORE_TYPE_DMESG:
434 part = &oops_log_partition;
435 record->type = PSTORE_TYPE_DMESG;
436 break;
437 case PSTORE_TYPE_PPC_COMMON:
438 sig = NVRAM_SIG_SYS;
439 part = &common_partition;
440 record->type = PSTORE_TYPE_PPC_COMMON;
441 record->id = PSTORE_TYPE_PPC_COMMON;
442 record->time.tv_sec = 0;
443 record->time.tv_nsec = 0;
444 break;
445#ifdef CONFIG_PPC_PSERIES
446 case PSTORE_TYPE_PPC_RTAS:
447 part = &rtas_log_partition;
448 record->type = PSTORE_TYPE_PPC_RTAS;
449 record->time.tv_sec = last_rtas_event;
450 record->time.tv_nsec = 0;
451 break;
452 case PSTORE_TYPE_PPC_OF:
453 sig = NVRAM_SIG_OF;
454 part = &of_config_partition;
455 record->type = PSTORE_TYPE_PPC_OF;
456 record->id = PSTORE_TYPE_PPC_OF;
457 record->time.tv_sec = 0;
458 record->time.tv_nsec = 0;
459 break;
460#endif
461#ifdef CONFIG_PPC_POWERNV
462 case PSTORE_TYPE_PPC_OPAL:
463 sig = NVRAM_SIG_FW;
464 part = &skiboot_partition;
465 record->type = PSTORE_TYPE_PPC_OPAL;
466 record->id = PSTORE_TYPE_PPC_OPAL;
467 record->time.tv_sec = 0;
468 record->time.tv_nsec = 0;
469 break;
470#endif
471 default:
472 return 0;
473 }
474
475 if (!part->os_partition) {
476 p = nvram_find_partition(part->name, sig, &size);
477 if (p <= 0) {
478 pr_err("nvram: Failed to find partition %s, "
479 "err %d\n", part->name, (int)p);
480 return 0;
481 }
482 part->index = p;
483 part->size = size;
484 }
485
486 buff = kmalloc(part->size, GFP_KERNEL);
487
488 if (!buff)
489 return -ENOMEM;
490
491 if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
492 kfree(buff);
493 return 0;
494 }
495
496 record->count = 0;
497
498 if (part->os_partition)
499 record->id = id_no;
500
501 if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
502 size_t length, hdr_size;
503
504 oops_hdr = (struct oops_log_info *)buff;
505 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
506 /* Old format oops header had 2-byte record size */
507 hdr_size = sizeof(u16);
508 length = be16_to_cpu(oops_hdr->version);
509 record->time.tv_sec = 0;
510 record->time.tv_nsec = 0;
511 } else {
512 hdr_size = sizeof(*oops_hdr);
513 length = be16_to_cpu(oops_hdr->report_length);
514 record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp);
515 record->time.tv_nsec = 0;
516 }
517 record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
518 kfree(buff);
519 if (record->buf == NULL)
520 return -ENOMEM;
521
522 record->ecc_notice_size = 0;
523 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
524 record->compressed = true;
525 else
526 record->compressed = false;
527 return length;
528 }
529
530 record->buf = buff;
531 return part->size;
532}
533
534static struct pstore_info nvram_pstore_info = {
535 .owner = THIS_MODULE,
536 .name = "nvram",
537 .flags = PSTORE_FLAGS_DMESG,
538 .open = nvram_pstore_open,
539 .read = nvram_pstore_read,
540 .write = nvram_pstore_write,
541};
542
543static int __init nvram_pstore_init(void)
544{
545 int rc = 0;
546
547 if (machine_is(pseries)) {
548 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
549 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
550 } else
551 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
552
553 nvram_pstore_info.buf = oops_data;
554 nvram_pstore_info.bufsize = oops_data_sz;
555
556 rc = pstore_register(&nvram_pstore_info);
557 if (rc && (rc != -EPERM))
558 /* Print error only when pstore.backend == nvram */
559 pr_err("nvram: pstore_register() failed, returned %d. "
560 "Defaults to kmsg_dump\n", rc);
561
562 return rc;
563}
564#else
565static int __init nvram_pstore_init(void)
566{
567 return -1;
568}
569#endif
570
571void __init nvram_init_oops_partition(int rtas_partition_exists)
572{
573 int rc;
574
575 rc = nvram_init_os_partition(&oops_log_partition);
576 if (rc != 0) {
577#ifdef CONFIG_PPC_PSERIES
578 if (!rtas_partition_exists) {
579 pr_err("nvram: Failed to initialize oops partition!");
580 return;
581 }
582 pr_notice("nvram: Using %s partition to log both"
583 " RTAS errors and oops/panic reports\n",
584 rtas_log_partition.name);
585 memcpy(&oops_log_partition, &rtas_log_partition,
586 sizeof(rtas_log_partition));
587#else
588 pr_err("nvram: Failed to initialize oops partition!");
589 return;
590#endif
591 }
592 oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
593 if (!oops_buf) {
594 pr_err("nvram: No memory for %s partition\n",
595 oops_log_partition.name);
596 return;
597 }
598 oops_data = oops_buf + sizeof(struct oops_log_info);
599 oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
600
601 rc = nvram_pstore_init();
602
603 if (!rc)
604 return;
605
606 /*
607 * Figure compression (preceded by elimination of each line's <n>
608 * severity prefix) will reduce the oops/panic report to at most
609 * 45% of its original size.
610 */
611 big_oops_buf_sz = (oops_data_sz * 100) / 45;
612 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
613 if (big_oops_buf) {
614 stream.workspace = kmalloc(zlib_deflate_workspacesize(
615 WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
616 if (!stream.workspace) {
617 pr_err("nvram: No memory for compression workspace; "
618 "skipping compression of %s partition data\n",
619 oops_log_partition.name);
620 kfree(big_oops_buf);
621 big_oops_buf = NULL;
622 }
623 } else {
624 pr_err("No memory for uncompressed %s data; "
625 "skipping compression\n", oops_log_partition.name);
626 stream.workspace = NULL;
627 }
628
629 rc = kmsg_dump_register(&nvram_kmsg_dumper);
630 if (rc != 0) {
631 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
632 kfree(oops_buf);
633 kfree(big_oops_buf);
634 kfree(stream.workspace);
635 }
636}
637
638/*
639 * This is our kmsg_dump callback, called after an oops or panic report
640 * has been written to the printk buffer. We want to capture as much
641 * of the printk buffer as possible. First, capture as much as we can
642 * that we think will compress sufficiently to fit in the lnx,oops-log
643 * partition. If that's too much, go back and capture uncompressed text.
644 */
645static void oops_to_nvram(struct kmsg_dumper *dumper,
646 struct kmsg_dump_detail *detail)
647{
648 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
649 static unsigned int oops_count = 0;
650 static struct kmsg_dump_iter iter;
651 static bool panicking = false;
652 static DEFINE_SPINLOCK(lock);
653 unsigned long flags;
654 size_t text_len;
655 unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
656 int rc = -1;
657
658 switch (detail->reason) {
659 case KMSG_DUMP_SHUTDOWN:
660 /* These are almost always orderly shutdowns. */
661 return;
662 case KMSG_DUMP_OOPS:
663 break;
664 case KMSG_DUMP_PANIC:
665 panicking = true;
666 break;
667 case KMSG_DUMP_EMERG:
668 if (panicking)
669 /* Panic report already captured. */
670 return;
671 break;
672 default:
673 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
674 __func__, (int) detail->reason);
675 return;
676 }
677
678 if (clobbering_unread_rtas_event())
679 return;
680
681 if (!spin_trylock_irqsave(&lock, flags))
682 return;
683
684 if (big_oops_buf) {
685 kmsg_dump_rewind(&iter);
686 kmsg_dump_get_buffer(&iter, false,
687 big_oops_buf, big_oops_buf_sz, &text_len);
688 rc = zip_oops(text_len);
689 }
690 if (rc != 0) {
691 kmsg_dump_rewind(&iter);
692 kmsg_dump_get_buffer(&iter, false,
693 oops_data, oops_data_sz, &text_len);
694 err_type = ERR_TYPE_KERNEL_PANIC;
695 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
696 oops_hdr->report_length = cpu_to_be16(text_len);
697 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
698 }
699
700 (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
701 (int) (sizeof(*oops_hdr) + text_len), err_type,
702 ++oops_count);
703
704 spin_unlock_irqrestore(&lock, flags);
705}
706
707#ifdef DEBUG_NVRAM
708static void __init nvram_print_partitions(char * label)
709{
710 struct nvram_partition * tmp_part;
711
712 printk(KERN_WARNING "--------%s---------\n", label);
713 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
714 list_for_each_entry(tmp_part, &nvram_partitions, partition) {
715 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12.12s\n",
716 tmp_part->index, tmp_part->header.signature,
717 tmp_part->header.checksum, tmp_part->header.length,
718 tmp_part->header.name);
719 }
720}
721#endif
722
723
724static int __init nvram_write_header(struct nvram_partition * part)
725{
726 loff_t tmp_index;
727 int rc;
728 struct nvram_header phead;
729
730 memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
731 phead.length = cpu_to_be16(phead.length);
732
733 tmp_index = part->index;
734 rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
735
736 return rc;
737}
738
739
740static unsigned char __init nvram_checksum(struct nvram_header *p)
741{
742 unsigned int c_sum, c_sum2;
743 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
744 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
745
746 /* The sum may have spilled into the 3rd byte. Fold it back. */
747 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
748 /* The sum cannot exceed 2 bytes. Fold it into a checksum */
749 c_sum2 = (c_sum >> 8) + (c_sum << 8);
750 c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
751 return c_sum;
752}
753
754/*
755 * Per the criteria passed via nvram_remove_partition(), should this
756 * partition be removed? 1=remove, 0=keep
757 */
758static int __init nvram_can_remove_partition(struct nvram_partition *part,
759 const char *name, int sig, const char *exceptions[])
760{
761 if (part->header.signature != sig)
762 return 0;
763 if (name) {
764 if (strncmp(name, part->header.name, 12))
765 return 0;
766 } else if (exceptions) {
767 const char **except;
768 for (except = exceptions; *except; except++) {
769 if (!strncmp(*except, part->header.name, 12))
770 return 0;
771 }
772 }
773 return 1;
774}
775
776/**
777 * nvram_remove_partition - Remove one or more partitions in nvram
778 * @name: name of the partition to remove, or NULL for a
779 * signature only match
780 * @sig: signature of the partition(s) to remove
781 * @exceptions: When removing all partitions with a matching signature,
782 * leave these alone.
783 */
784
785int __init nvram_remove_partition(const char *name, int sig,
786 const char *exceptions[])
787{
788 struct nvram_partition *part, *prev, *tmp;
789 int rc;
790
791 list_for_each_entry(part, &nvram_partitions, partition) {
792 if (!nvram_can_remove_partition(part, name, sig, exceptions))
793 continue;
794
795 /* Make partition a free partition */
796 part->header.signature = NVRAM_SIG_FREE;
797 memset(part->header.name, 'w', 12);
798 part->header.checksum = nvram_checksum(&part->header);
799 rc = nvram_write_header(part);
800 if (rc <= 0) {
801 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
802 return rc;
803 }
804 }
805
806 /* Merge contiguous ones */
807 prev = NULL;
808 list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
809 if (part->header.signature != NVRAM_SIG_FREE) {
810 prev = NULL;
811 continue;
812 }
813 if (prev) {
814 prev->header.length += part->header.length;
815 prev->header.checksum = nvram_checksum(&prev->header);
816 rc = nvram_write_header(prev);
817 if (rc <= 0) {
818 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
819 return rc;
820 }
821 list_del(&part->partition);
822 kfree(part);
823 } else
824 prev = part;
825 }
826
827 return 0;
828}
829
830/**
831 * nvram_create_partition - Create a partition in nvram
832 * @name: name of the partition to create
833 * @sig: signature of the partition to create
834 * @req_size: size of data to allocate in bytes
835 * @min_size: minimum acceptable size (0 means req_size)
836 *
837 * Returns a negative error code or a positive nvram index
838 * of the beginning of the data area of the newly created
839 * partition. If you provided a min_size smaller than req_size
840 * you need to query for the actual size yourself after the
841 * call using nvram_partition_get_size().
842 */
843loff_t __init nvram_create_partition(const char *name, int sig,
844 int req_size, int min_size)
845{
846 struct nvram_partition *part;
847 struct nvram_partition *new_part;
848 struct nvram_partition *free_part = NULL;
849 static char nv_init_vals[16];
850 loff_t tmp_index;
851 long size = 0;
852 int rc;
853
854 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
855
856 /* Convert sizes from bytes to blocks */
857 req_size = ALIGN(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
858 min_size = ALIGN(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
859
860 /* If no minimum size specified, make it the same as the
861 * requested size
862 */
863 if (min_size == 0)
864 min_size = req_size;
865 if (min_size > req_size)
866 return -EINVAL;
867
868 /* Now add one block to each for the header */
869 req_size += 1;
870 min_size += 1;
871
872 /* Find a free partition that will give us the maximum needed size
873 If can't find one that will give us the minimum size needed */
874 list_for_each_entry(part, &nvram_partitions, partition) {
875 if (part->header.signature != NVRAM_SIG_FREE)
876 continue;
877
878 if (part->header.length >= req_size) {
879 size = req_size;
880 free_part = part;
881 break;
882 }
883 if (part->header.length > size &&
884 part->header.length >= min_size) {
885 size = part->header.length;
886 free_part = part;
887 }
888 }
889 if (!size)
890 return -ENOSPC;
891
892 /* Create our OS partition */
893 new_part = kzalloc(sizeof(*new_part), GFP_KERNEL);
894 if (!new_part) {
895 pr_err("%s: kmalloc failed\n", __func__);
896 return -ENOMEM;
897 }
898
899 new_part->index = free_part->index;
900 new_part->header.signature = sig;
901 new_part->header.length = size;
902 memcpy(new_part->header.name, name, strnlen(name, sizeof(new_part->header.name)));
903 new_part->header.checksum = nvram_checksum(&new_part->header);
904
905 rc = nvram_write_header(new_part);
906 if (rc <= 0) {
907 pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
908 kfree(new_part);
909 return rc;
910 }
911 list_add_tail(&new_part->partition, &free_part->partition);
912
913 /* Adjust or remove the partition we stole the space from */
914 if (free_part->header.length > size) {
915 free_part->index += size * NVRAM_BLOCK_LEN;
916 free_part->header.length -= size;
917 free_part->header.checksum = nvram_checksum(&free_part->header);
918 rc = nvram_write_header(free_part);
919 if (rc <= 0) {
920 pr_err("%s: nvram_write_header failed (%d)\n",
921 __func__, rc);
922 return rc;
923 }
924 } else {
925 list_del(&free_part->partition);
926 kfree(free_part);
927 }
928
929 /* Clear the new partition */
930 for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
931 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
932 tmp_index += NVRAM_BLOCK_LEN) {
933 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
934 if (rc <= 0) {
935 pr_err("%s: nvram_write failed (%d)\n",
936 __func__, rc);
937 return rc;
938 }
939 }
940
941 return new_part->index + NVRAM_HEADER_LEN;
942}
943
944/**
945 * nvram_get_partition_size - Get the data size of an nvram partition
946 * @data_index: This is the offset of the start of the data of
947 * the partition. The same value that is returned by
948 * nvram_create_partition().
949 */
950int nvram_get_partition_size(loff_t data_index)
951{
952 struct nvram_partition *part;
953
954 list_for_each_entry(part, &nvram_partitions, partition) {
955 if (part->index + NVRAM_HEADER_LEN == data_index)
956 return (part->header.length - 1) * NVRAM_BLOCK_LEN;
957 }
958 return -1;
959}
960
961
962/**
963 * nvram_find_partition - Find an nvram partition by signature and name
964 * @name: Name of the partition or NULL for any name
965 * @sig: Signature to test against
966 * @out_size: if non-NULL, returns the size of the data part of the partition
967 */
968loff_t nvram_find_partition(const char *name, int sig, int *out_size)
969{
970 struct nvram_partition *p;
971
972 list_for_each_entry(p, &nvram_partitions, partition) {
973 if (p->header.signature == sig &&
974 (!name || !strncmp(p->header.name, name, 12))) {
975 if (out_size)
976 *out_size = (p->header.length - 1) *
977 NVRAM_BLOCK_LEN;
978 return p->index + NVRAM_HEADER_LEN;
979 }
980 }
981 return 0;
982}
983
984int __init nvram_scan_partitions(void)
985{
986 loff_t cur_index = 0;
987 struct nvram_header phead;
988 struct nvram_partition * tmp_part;
989 unsigned char c_sum;
990 char * header;
991 int total_size;
992 int err;
993
994 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
995 return -ENODEV;
996 total_size = ppc_md.nvram_size();
997
998 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
999 if (!header) {
1000 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
1001 return -ENOMEM;
1002 }
1003
1004 while (cur_index < total_size) {
1005
1006 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
1007 if (err != NVRAM_HEADER_LEN) {
1008 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
1009 "nvram partitions\n");
1010 goto out;
1011 }
1012
1013 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
1014
1015 memcpy(&phead, header, NVRAM_HEADER_LEN);
1016
1017 phead.length = be16_to_cpu(phead.length);
1018
1019 err = 0;
1020 c_sum = nvram_checksum(&phead);
1021 if (c_sum != phead.checksum) {
1022 printk(KERN_WARNING "WARNING: nvram partition checksum"
1023 " was %02x, should be %02x!\n",
1024 phead.checksum, c_sum);
1025 printk(KERN_WARNING "Terminating nvram partition scan\n");
1026 goto out;
1027 }
1028 if (!phead.length) {
1029 printk(KERN_WARNING "WARNING: nvram corruption "
1030 "detected: 0-length partition\n");
1031 goto out;
1032 }
1033 tmp_part = kmalloc(sizeof(*tmp_part), GFP_KERNEL);
1034 err = -ENOMEM;
1035 if (!tmp_part) {
1036 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
1037 goto out;
1038 }
1039
1040 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
1041 tmp_part->index = cur_index;
1042 list_add_tail(&tmp_part->partition, &nvram_partitions);
1043
1044 cur_index += phead.length * NVRAM_BLOCK_LEN;
1045 }
1046 err = 0;
1047
1048#ifdef DEBUG_NVRAM
1049 nvram_print_partitions("NVRAM Partitions");
1050#endif
1051
1052 out:
1053 kfree(header);
1054 return err;
1055}