Commit | Line | Data |
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1da177e4 LT |
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 <asm/uaccess.h> | |
30 | #include <asm/nvram.h> | |
31 | #include <asm/rtas.h> | |
32 | #include <asm/prom.h> | |
33 | #include <asm/machdep.h> | |
1da177e4 LT |
34 | |
35 | #undef DEBUG_NVRAM | |
36 | ||
1da177e4 LT |
37 | static struct nvram_partition * nvram_part; |
38 | static long nvram_error_log_index = -1; | |
39 | static long nvram_error_log_size = 0; | |
40 | ||
1da177e4 LT |
41 | struct err_log_info { |
42 | int error_type; | |
43 | unsigned int seq_num; | |
44 | }; | |
45 | ||
46 | static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin) | |
47 | { | |
48 | int size; | |
49 | ||
50 | if (ppc_md.nvram_size == NULL) | |
51 | return -ENODEV; | |
52 | size = ppc_md.nvram_size(); | |
53 | ||
54 | switch (origin) { | |
55 | case 1: | |
56 | offset += file->f_pos; | |
57 | break; | |
58 | case 2: | |
59 | offset += size; | |
60 | break; | |
61 | } | |
62 | if (offset < 0) | |
63 | return -EINVAL; | |
64 | file->f_pos = offset; | |
65 | return file->f_pos; | |
66 | } | |
67 | ||
68 | ||
69 | static ssize_t dev_nvram_read(struct file *file, char __user *buf, | |
70 | size_t count, loff_t *ppos) | |
71 | { | |
f9ce299f AB |
72 | ssize_t ret; |
73 | char *tmp = NULL; | |
74 | ssize_t size; | |
1da177e4 | 75 | |
f9ce299f AB |
76 | ret = -ENODEV; |
77 | if (!ppc_md.nvram_size) | |
78 | goto out; | |
79 | ||
80 | ret = 0; | |
1da177e4 | 81 | size = ppc_md.nvram_size(); |
f9ce299f AB |
82 | if (*ppos >= size || size < 0) |
83 | goto out; | |
1da177e4 | 84 | |
f9ce299f AB |
85 | count = min_t(size_t, count, size - *ppos); |
86 | count = min(count, PAGE_SIZE); | |
1da177e4 | 87 | |
f9ce299f AB |
88 | ret = -ENOMEM; |
89 | tmp = kmalloc(count, GFP_KERNEL); | |
90 | if (!tmp) | |
91 | goto out; | |
1da177e4 | 92 | |
f9ce299f AB |
93 | ret = ppc_md.nvram_read(tmp, count, ppos); |
94 | if (ret <= 0) | |
95 | goto out; | |
96 | ||
97 | if (copy_to_user(buf, tmp, ret)) | |
98 | ret = -EFAULT; | |
1da177e4 | 99 | |
f9ce299f AB |
100 | out: |
101 | kfree(tmp); | |
102 | return ret; | |
1da177e4 LT |
103 | |
104 | } | |
105 | ||
106 | static ssize_t dev_nvram_write(struct file *file, const char __user *buf, | |
f9ce299f | 107 | size_t count, loff_t *ppos) |
1da177e4 | 108 | { |
f9ce299f AB |
109 | ssize_t ret; |
110 | char *tmp = NULL; | |
111 | ssize_t size; | |
1da177e4 | 112 | |
f9ce299f AB |
113 | ret = -ENODEV; |
114 | if (!ppc_md.nvram_size) | |
115 | goto out; | |
116 | ||
117 | ret = 0; | |
1da177e4 | 118 | size = ppc_md.nvram_size(); |
f9ce299f AB |
119 | if (*ppos >= size || size < 0) |
120 | goto out; | |
1da177e4 | 121 | |
f9ce299f AB |
122 | count = min_t(size_t, count, size - *ppos); |
123 | count = min(count, PAGE_SIZE); | |
1da177e4 | 124 | |
f9ce299f AB |
125 | ret = -ENOMEM; |
126 | tmp = kmalloc(count, GFP_KERNEL); | |
127 | if (!tmp) | |
128 | goto out; | |
129 | ||
130 | ret = -EFAULT; | |
131 | if (copy_from_user(tmp, buf, count)) | |
132 | goto out; | |
133 | ||
134 | ret = ppc_md.nvram_write(tmp, count, ppos); | |
135 | ||
136 | out: | |
137 | kfree(tmp); | |
138 | return ret; | |
1da177e4 | 139 | |
1da177e4 LT |
140 | } |
141 | ||
142 | static int dev_nvram_ioctl(struct inode *inode, struct file *file, | |
143 | unsigned int cmd, unsigned long arg) | |
144 | { | |
145 | switch(cmd) { | |
146 | #ifdef CONFIG_PPC_PMAC | |
147 | case OBSOLETE_PMAC_NVRAM_GET_OFFSET: | |
148 | printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); | |
149 | case IOC_NVRAM_GET_OFFSET: { | |
150 | int part, offset; | |
151 | ||
e8222502 | 152 | if (!machine_is(powermac)) |
1da177e4 LT |
153 | return -EINVAL; |
154 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
155 | return -EFAULT; | |
156 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
157 | return -EINVAL; | |
158 | offset = pmac_get_partition(part); | |
159 | if (offset < 0) | |
160 | return offset; | |
161 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
162 | return -EFAULT; | |
163 | return 0; | |
164 | } | |
165 | #endif /* CONFIG_PPC_PMAC */ | |
af308377 SR |
166 | default: |
167 | return -EINVAL; | |
1da177e4 | 168 | } |
1da177e4 LT |
169 | } |
170 | ||
5dfe4c96 | 171 | const struct file_operations nvram_fops = { |
1da177e4 LT |
172 | .owner = THIS_MODULE, |
173 | .llseek = dev_nvram_llseek, | |
174 | .read = dev_nvram_read, | |
175 | .write = dev_nvram_write, | |
176 | .ioctl = dev_nvram_ioctl, | |
177 | }; | |
178 | ||
179 | static struct miscdevice nvram_dev = { | |
180 | NVRAM_MINOR, | |
181 | "nvram", | |
182 | &nvram_fops | |
183 | }; | |
184 | ||
185 | ||
186 | #ifdef DEBUG_NVRAM | |
187 | static void nvram_print_partitions(char * label) | |
188 | { | |
189 | struct list_head * p; | |
190 | struct nvram_partition * tmp_part; | |
191 | ||
192 | printk(KERN_WARNING "--------%s---------\n", label); | |
193 | printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n"); | |
194 | list_for_each(p, &nvram_part->partition) { | |
195 | tmp_part = list_entry(p, struct nvram_partition, partition); | |
5a43ee65 | 196 | printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%s\n", |
1da177e4 LT |
197 | tmp_part->index, tmp_part->header.signature, |
198 | tmp_part->header.checksum, tmp_part->header.length, | |
199 | tmp_part->header.name); | |
200 | } | |
201 | } | |
202 | #endif | |
203 | ||
204 | ||
205 | static int nvram_write_header(struct nvram_partition * part) | |
206 | { | |
207 | loff_t tmp_index; | |
208 | int rc; | |
209 | ||
210 | tmp_index = part->index; | |
211 | rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index); | |
212 | ||
213 | return rc; | |
214 | } | |
215 | ||
216 | ||
217 | static unsigned char nvram_checksum(struct nvram_header *p) | |
218 | { | |
219 | unsigned int c_sum, c_sum2; | |
220 | unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */ | |
221 | c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5]; | |
222 | ||
223 | /* The sum may have spilled into the 3rd byte. Fold it back. */ | |
224 | c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff; | |
225 | /* The sum cannot exceed 2 bytes. Fold it into a checksum */ | |
226 | c_sum2 = (c_sum >> 8) + (c_sum << 8); | |
227 | c_sum = ((c_sum + c_sum2) >> 8) & 0xff; | |
228 | return c_sum; | |
229 | } | |
230 | ||
231 | ||
232 | /* | |
233 | * Find an nvram partition, sig can be 0 for any | |
234 | * partition or name can be NULL for any name, else | |
235 | * tries to match both | |
236 | */ | |
237 | struct nvram_partition *nvram_find_partition(int sig, const char *name) | |
238 | { | |
239 | struct nvram_partition * part; | |
240 | struct list_head * p; | |
241 | ||
242 | list_for_each(p, &nvram_part->partition) { | |
243 | part = list_entry(p, struct nvram_partition, partition); | |
244 | ||
245 | if (sig && part->header.signature != sig) | |
246 | continue; | |
247 | if (name && 0 != strncmp(name, part->header.name, 12)) | |
248 | continue; | |
249 | return part; | |
250 | } | |
251 | return NULL; | |
252 | } | |
253 | EXPORT_SYMBOL(nvram_find_partition); | |
254 | ||
255 | ||
256 | static int nvram_remove_os_partition(void) | |
257 | { | |
258 | struct list_head *i; | |
259 | struct list_head *j; | |
260 | struct nvram_partition * part; | |
261 | struct nvram_partition * cur_part; | |
262 | int rc; | |
263 | ||
264 | list_for_each(i, &nvram_part->partition) { | |
265 | part = list_entry(i, struct nvram_partition, partition); | |
266 | if (part->header.signature != NVRAM_SIG_OS) | |
267 | continue; | |
268 | ||
269 | /* Make os partition a free partition */ | |
270 | part->header.signature = NVRAM_SIG_FREE; | |
271 | sprintf(part->header.name, "wwwwwwwwwwww"); | |
272 | part->header.checksum = nvram_checksum(&part->header); | |
273 | ||
274 | /* Merge contiguous free partitions backwards */ | |
275 | list_for_each_prev(j, &part->partition) { | |
276 | cur_part = list_entry(j, struct nvram_partition, partition); | |
277 | if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { | |
278 | break; | |
279 | } | |
280 | ||
281 | part->header.length += cur_part->header.length; | |
282 | part->header.checksum = nvram_checksum(&part->header); | |
283 | part->index = cur_part->index; | |
284 | ||
285 | list_del(&cur_part->partition); | |
286 | kfree(cur_part); | |
287 | j = &part->partition; /* fixup our loop */ | |
288 | } | |
289 | ||
290 | /* Merge contiguous free partitions forwards */ | |
291 | list_for_each(j, &part->partition) { | |
292 | cur_part = list_entry(j, struct nvram_partition, partition); | |
293 | if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { | |
294 | break; | |
295 | } | |
296 | ||
297 | part->header.length += cur_part->header.length; | |
298 | part->header.checksum = nvram_checksum(&part->header); | |
299 | ||
300 | list_del(&cur_part->partition); | |
301 | kfree(cur_part); | |
302 | j = &part->partition; /* fixup our loop */ | |
303 | } | |
304 | ||
305 | rc = nvram_write_header(part); | |
306 | if (rc <= 0) { | |
307 | printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc); | |
308 | return rc; | |
309 | } | |
310 | ||
311 | } | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
316 | /* nvram_create_os_partition | |
317 | * | |
318 | * Create a OS linux partition to buffer error logs. | |
319 | * Will create a partition starting at the first free | |
320 | * space found if space has enough room. | |
321 | */ | |
322 | static int nvram_create_os_partition(void) | |
323 | { | |
a341ad97 AB |
324 | struct nvram_partition *part; |
325 | struct nvram_partition *new_part; | |
0339ad77 | 326 | struct nvram_partition *free_part = NULL; |
1da177e4 LT |
327 | int seq_init[2] = { 0, 0 }; |
328 | loff_t tmp_index; | |
329 | long size = 0; | |
330 | int rc; | |
331 | ||
332 | /* Find a free partition that will give us the maximum needed size | |
333 | If can't find one that will give us the minimum size needed */ | |
a341ad97 | 334 | list_for_each_entry(part, &nvram_part->partition, partition) { |
1da177e4 LT |
335 | if (part->header.signature != NVRAM_SIG_FREE) |
336 | continue; | |
337 | ||
338 | if (part->header.length >= NVRAM_MAX_REQ) { | |
339 | size = NVRAM_MAX_REQ; | |
340 | free_part = part; | |
341 | break; | |
342 | } | |
343 | if (!size && part->header.length >= NVRAM_MIN_REQ) { | |
344 | size = NVRAM_MIN_REQ; | |
345 | free_part = part; | |
346 | } | |
347 | } | |
0339ad77 | 348 | if (!size) |
1da177e4 | 349 | return -ENOSPC; |
1da177e4 LT |
350 | |
351 | /* Create our OS partition */ | |
0339ad77 | 352 | new_part = kmalloc(sizeof(*new_part), GFP_KERNEL); |
1da177e4 LT |
353 | if (!new_part) { |
354 | printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n"); | |
355 | return -ENOMEM; | |
356 | } | |
357 | ||
358 | new_part->index = free_part->index; | |
359 | new_part->header.signature = NVRAM_SIG_OS; | |
360 | new_part->header.length = size; | |
0339ad77 | 361 | strcpy(new_part->header.name, "ppc64,linux"); |
1da177e4 LT |
362 | new_part->header.checksum = nvram_checksum(&new_part->header); |
363 | ||
364 | rc = nvram_write_header(new_part); | |
365 | if (rc <= 0) { | |
366 | printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \ | |
367 | failed (%d)\n", rc); | |
368 | return rc; | |
369 | } | |
370 | ||
371 | /* make sure and initialize to zero the sequence number and the error | |
372 | type logged */ | |
373 | tmp_index = new_part->index + NVRAM_HEADER_LEN; | |
374 | rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index); | |
375 | if (rc <= 0) { | |
0339ad77 | 376 | printk(KERN_ERR "nvram_create_os_partition: nvram_write " |
377 | "failed (%d)\n", rc); | |
1da177e4 LT |
378 | return rc; |
379 | } | |
380 | ||
381 | nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN; | |
382 | nvram_error_log_size = ((part->header.length - 1) * | |
383 | NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); | |
384 | ||
385 | list_add_tail(&new_part->partition, &free_part->partition); | |
386 | ||
387 | if (free_part->header.length <= size) { | |
388 | list_del(&free_part->partition); | |
389 | kfree(free_part); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | /* Adjust the partition we stole the space from */ | |
394 | free_part->index += size * NVRAM_BLOCK_LEN; | |
395 | free_part->header.length -= size; | |
396 | free_part->header.checksum = nvram_checksum(&free_part->header); | |
397 | ||
398 | rc = nvram_write_header(free_part); | |
399 | if (rc <= 0) { | |
400 | printk(KERN_ERR "nvram_create_os_partition: nvram_write_header " | |
401 | "failed (%d)\n", rc); | |
402 | return rc; | |
403 | } | |
404 | ||
405 | return 0; | |
406 | } | |
407 | ||
408 | ||
409 | /* nvram_setup_partition | |
410 | * | |
411 | * This will setup the partition we need for buffering the | |
412 | * error logs and cleanup partitions if needed. | |
413 | * | |
414 | * The general strategy is the following: | |
415 | * 1.) If there is ppc64,linux partition large enough then use it. | |
416 | * 2.) If there is not a ppc64,linux partition large enough, search | |
417 | * for a free partition that is large enough. | |
418 | * 3.) If there is not a free partition large enough remove | |
419 | * _all_ OS partitions and consolidate the space. | |
420 | * 4.) Will first try getting a chunk that will satisfy the maximum | |
421 | * error log size (NVRAM_MAX_REQ). | |
422 | * 5.) If the max chunk cannot be allocated then try finding a chunk | |
423 | * that will satisfy the minum needed (NVRAM_MIN_REQ). | |
424 | */ | |
425 | static int nvram_setup_partition(void) | |
426 | { | |
427 | struct list_head * p; | |
428 | struct nvram_partition * part; | |
429 | int rc; | |
430 | ||
431 | /* For now, we don't do any of this on pmac, until I | |
432 | * have figured out if it's worth killing some unused stuffs | |
433 | * in our nvram, as Apple defined partitions use pretty much | |
434 | * all of the space | |
435 | */ | |
e8222502 | 436 | if (machine_is(powermac)) |
1da177e4 LT |
437 | return -ENOSPC; |
438 | ||
439 | /* see if we have an OS partition that meets our needs. | |
440 | will try getting the max we need. If not we'll delete | |
441 | partitions and try again. */ | |
442 | list_for_each(p, &nvram_part->partition) { | |
443 | part = list_entry(p, struct nvram_partition, partition); | |
444 | if (part->header.signature != NVRAM_SIG_OS) | |
445 | continue; | |
446 | ||
447 | if (strcmp(part->header.name, "ppc64,linux")) | |
448 | continue; | |
449 | ||
450 | if (part->header.length >= NVRAM_MIN_REQ) { | |
451 | /* found our partition */ | |
452 | nvram_error_log_index = part->index + NVRAM_HEADER_LEN; | |
453 | nvram_error_log_size = ((part->header.length - 1) * | |
454 | NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); | |
455 | return 0; | |
456 | } | |
457 | } | |
458 | ||
459 | /* try creating a partition with the free space we have */ | |
460 | rc = nvram_create_os_partition(); | |
461 | if (!rc) { | |
462 | return 0; | |
463 | } | |
464 | ||
465 | /* need to free up some space */ | |
466 | rc = nvram_remove_os_partition(); | |
467 | if (rc) { | |
468 | return rc; | |
469 | } | |
470 | ||
471 | /* create a partition in this new space */ | |
472 | rc = nvram_create_os_partition(); | |
473 | if (rc) { | |
474 | printk(KERN_ERR "nvram_create_os_partition: Could not find a " | |
475 | "NVRAM partition large enough\n"); | |
476 | return rc; | |
477 | } | |
478 | ||
479 | return 0; | |
480 | } | |
481 | ||
482 | ||
483 | static int nvram_scan_partitions(void) | |
484 | { | |
485 | loff_t cur_index = 0; | |
486 | struct nvram_header phead; | |
487 | struct nvram_partition * tmp_part; | |
488 | unsigned char c_sum; | |
489 | char * header; | |
490 | int total_size; | |
491 | int err; | |
492 | ||
493 | if (ppc_md.nvram_size == NULL) | |
494 | return -ENODEV; | |
495 | total_size = ppc_md.nvram_size(); | |
496 | ||
5cbded58 | 497 | header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL); |
1da177e4 LT |
498 | if (!header) { |
499 | printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n"); | |
500 | return -ENOMEM; | |
501 | } | |
502 | ||
503 | while (cur_index < total_size) { | |
504 | ||
505 | err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index); | |
506 | if (err != NVRAM_HEADER_LEN) { | |
507 | printk(KERN_ERR "nvram_scan_partitions: Error parsing " | |
508 | "nvram partitions\n"); | |
509 | goto out; | |
510 | } | |
511 | ||
512 | cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */ | |
513 | ||
514 | memcpy(&phead, header, NVRAM_HEADER_LEN); | |
515 | ||
516 | err = 0; | |
517 | c_sum = nvram_checksum(&phead); | |
518 | if (c_sum != phead.checksum) { | |
519 | printk(KERN_WARNING "WARNING: nvram partition checksum" | |
520 | " was %02x, should be %02x!\n", | |
521 | phead.checksum, c_sum); | |
522 | printk(KERN_WARNING "Terminating nvram partition scan\n"); | |
523 | goto out; | |
524 | } | |
525 | if (!phead.length) { | |
526 | printk(KERN_WARNING "WARNING: nvram corruption " | |
527 | "detected: 0-length partition\n"); | |
528 | goto out; | |
529 | } | |
530 | tmp_part = (struct nvram_partition *) | |
531 | kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); | |
532 | err = -ENOMEM; | |
533 | if (!tmp_part) { | |
534 | printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n"); | |
535 | goto out; | |
536 | } | |
537 | ||
538 | memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN); | |
539 | tmp_part->index = cur_index; | |
540 | list_add_tail(&tmp_part->partition, &nvram_part->partition); | |
541 | ||
542 | cur_index += phead.length * NVRAM_BLOCK_LEN; | |
543 | } | |
544 | err = 0; | |
545 | ||
546 | out: | |
547 | kfree(header); | |
548 | return err; | |
549 | } | |
550 | ||
551 | static int __init nvram_init(void) | |
552 | { | |
553 | int error; | |
554 | int rc; | |
555 | ||
556 | if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0) | |
557 | return -ENODEV; | |
558 | ||
559 | rc = misc_register(&nvram_dev); | |
560 | if (rc != 0) { | |
561 | printk(KERN_ERR "nvram_init: failed to register device\n"); | |
562 | return rc; | |
563 | } | |
564 | ||
565 | /* initialize our anchor for the nvram partition list */ | |
5cbded58 | 566 | nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); |
1da177e4 LT |
567 | if (!nvram_part) { |
568 | printk(KERN_ERR "nvram_init: Failed kmalloc\n"); | |
569 | return -ENOMEM; | |
570 | } | |
571 | INIT_LIST_HEAD(&nvram_part->partition); | |
572 | ||
573 | /* Get all the NVRAM partitions */ | |
574 | error = nvram_scan_partitions(); | |
575 | if (error) { | |
576 | printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n"); | |
577 | return error; | |
578 | } | |
579 | ||
580 | if(nvram_setup_partition()) | |
581 | printk(KERN_WARNING "nvram_init: Could not find nvram partition" | |
582 | " for nvram buffered error logging.\n"); | |
583 | ||
584 | #ifdef DEBUG_NVRAM | |
585 | nvram_print_partitions("NVRAM Partitions"); | |
586 | #endif | |
587 | ||
588 | return rc; | |
589 | } | |
590 | ||
591 | void __exit nvram_cleanup(void) | |
592 | { | |
593 | misc_deregister( &nvram_dev ); | |
594 | } | |
595 | ||
596 | ||
597 | #ifdef CONFIG_PPC_PSERIES | |
598 | ||
599 | /* nvram_write_error_log | |
600 | * | |
601 | * We need to buffer the error logs into nvram to ensure that we have | |
602 | * the failure information to decode. If we have a severe error there | |
603 | * is no way to guarantee that the OS or the machine is in a state to | |
604 | * get back to user land and write the error to disk. For example if | |
605 | * the SCSI device driver causes a Machine Check by writing to a bad | |
606 | * IO address, there is no way of guaranteeing that the device driver | |
607 | * is in any state that is would also be able to write the error data | |
608 | * captured to disk, thus we buffer it in NVRAM for analysis on the | |
609 | * next boot. | |
610 | * | |
611 | * In NVRAM the partition containing the error log buffer will looks like: | |
612 | * Header (in bytes): | |
613 | * +-----------+----------+--------+------------+------------------+ | |
614 | * | signature | checksum | length | name | data | | |
615 | * |0 |1 |2 3|4 15|16 length-1| | |
616 | * +-----------+----------+--------+------------+------------------+ | |
617 | * | |
618 | * The 'data' section would look like (in bytes): | |
619 | * +--------------+------------+-----------------------------------+ | |
620 | * | event_logged | sequence # | error log | | |
621 | * |0 3|4 7|8 nvram_error_log_size-1| | |
622 | * +--------------+------------+-----------------------------------+ | |
623 | * | |
624 | * event_logged: 0 if event has not been logged to syslog, 1 if it has | |
625 | * sequence #: The unique sequence # for each event. (until it wraps) | |
626 | * error log: The error log from event_scan | |
627 | */ | |
0f2342c8 LV |
628 | int nvram_write_error_log(char * buff, int length, |
629 | unsigned int err_type, unsigned int error_log_cnt) | |
1da177e4 LT |
630 | { |
631 | int rc; | |
632 | loff_t tmp_index; | |
633 | struct err_log_info info; | |
634 | ||
1da177e4 LT |
635 | if (nvram_error_log_index == -1) { |
636 | return -ESPIPE; | |
637 | } | |
638 | ||
639 | if (length > nvram_error_log_size) { | |
640 | length = nvram_error_log_size; | |
641 | } | |
642 | ||
643 | info.error_type = err_type; | |
644 | info.seq_num = error_log_cnt; | |
645 | ||
646 | tmp_index = nvram_error_log_index; | |
647 | ||
648 | rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index); | |
649 | if (rc <= 0) { | |
650 | printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); | |
651 | return rc; | |
652 | } | |
653 | ||
654 | rc = ppc_md.nvram_write(buff, length, &tmp_index); | |
655 | if (rc <= 0) { | |
656 | printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); | |
657 | return rc; | |
658 | } | |
659 | ||
660 | return 0; | |
661 | } | |
662 | ||
663 | /* nvram_read_error_log | |
664 | * | |
665 | * Reads nvram for error log for at most 'length' | |
666 | */ | |
0f2342c8 LV |
667 | int nvram_read_error_log(char * buff, int length, |
668 | unsigned int * err_type, unsigned int * error_log_cnt) | |
1da177e4 LT |
669 | { |
670 | int rc; | |
671 | loff_t tmp_index; | |
672 | struct err_log_info info; | |
673 | ||
674 | if (nvram_error_log_index == -1) | |
675 | return -1; | |
676 | ||
677 | if (length > nvram_error_log_size) | |
678 | length = nvram_error_log_size; | |
679 | ||
680 | tmp_index = nvram_error_log_index; | |
681 | ||
682 | rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index); | |
683 | if (rc <= 0) { | |
684 | printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); | |
685 | return rc; | |
686 | } | |
687 | ||
688 | rc = ppc_md.nvram_read(buff, length, &tmp_index); | |
689 | if (rc <= 0) { | |
690 | printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); | |
691 | return rc; | |
692 | } | |
693 | ||
0f2342c8 | 694 | *error_log_cnt = info.seq_num; |
1da177e4 LT |
695 | *err_type = info.error_type; |
696 | ||
697 | return 0; | |
698 | } | |
699 | ||
700 | /* This doesn't actually zero anything, but it sets the event_logged | |
701 | * word to tell that this event is safely in syslog. | |
702 | */ | |
703 | int nvram_clear_error_log(void) | |
704 | { | |
705 | loff_t tmp_index; | |
706 | int clear_word = ERR_FLAG_ALREADY_LOGGED; | |
707 | int rc; | |
708 | ||
709 | tmp_index = nvram_error_log_index; | |
710 | ||
711 | rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index); | |
712 | if (rc <= 0) { | |
713 | printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); | |
714 | return rc; | |
715 | } | |
716 | ||
717 | return 0; | |
718 | } | |
719 | ||
720 | #endif /* CONFIG_PPC_PSERIES */ | |
721 | ||
722 | module_init(nvram_init); | |
723 | module_exit(nvram_cleanup); | |
724 | MODULE_LICENSE("GPL"); |