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