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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 | ||
37 | static int nvram_scan_partitions(void); | |
38 | static int nvram_setup_partition(void); | |
39 | static int nvram_create_os_partition(void); | |
40 | static int nvram_remove_os_partition(void); | |
41 | ||
42 | static struct nvram_partition * nvram_part; | |
43 | static long nvram_error_log_index = -1; | |
44 | static long nvram_error_log_size = 0; | |
45 | ||
46 | int no_logging = 1; /* Until we initialize everything, | |
47 | * make sure we don't try logging | |
48 | * anything */ | |
49 | ||
50 | extern volatile int error_log_cnt; | |
51 | ||
52 | struct err_log_info { | |
53 | int error_type; | |
54 | unsigned int seq_num; | |
55 | }; | |
56 | ||
57 | static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin) | |
58 | { | |
59 | int size; | |
60 | ||
61 | if (ppc_md.nvram_size == NULL) | |
62 | return -ENODEV; | |
63 | size = ppc_md.nvram_size(); | |
64 | ||
65 | switch (origin) { | |
66 | case 1: | |
67 | offset += file->f_pos; | |
68 | break; | |
69 | case 2: | |
70 | offset += size; | |
71 | break; | |
72 | } | |
73 | if (offset < 0) | |
74 | return -EINVAL; | |
75 | file->f_pos = offset; | |
76 | return file->f_pos; | |
77 | } | |
78 | ||
79 | ||
80 | static ssize_t dev_nvram_read(struct file *file, char __user *buf, | |
81 | size_t count, loff_t *ppos) | |
82 | { | |
f9ce299f AB |
83 | ssize_t ret; |
84 | char *tmp = NULL; | |
85 | ssize_t size; | |
1da177e4 | 86 | |
f9ce299f AB |
87 | ret = -ENODEV; |
88 | if (!ppc_md.nvram_size) | |
89 | goto out; | |
90 | ||
91 | ret = 0; | |
1da177e4 | 92 | size = ppc_md.nvram_size(); |
f9ce299f AB |
93 | if (*ppos >= size || size < 0) |
94 | goto out; | |
1da177e4 | 95 | |
f9ce299f AB |
96 | count = min_t(size_t, count, size - *ppos); |
97 | count = min(count, PAGE_SIZE); | |
1da177e4 | 98 | |
f9ce299f AB |
99 | ret = -ENOMEM; |
100 | tmp = kmalloc(count, GFP_KERNEL); | |
101 | if (!tmp) | |
102 | goto out; | |
1da177e4 | 103 | |
f9ce299f AB |
104 | ret = ppc_md.nvram_read(tmp, count, ppos); |
105 | if (ret <= 0) | |
106 | goto out; | |
107 | ||
108 | if (copy_to_user(buf, tmp, ret)) | |
109 | ret = -EFAULT; | |
1da177e4 | 110 | |
f9ce299f AB |
111 | out: |
112 | kfree(tmp); | |
113 | return ret; | |
1da177e4 LT |
114 | |
115 | } | |
116 | ||
117 | static ssize_t dev_nvram_write(struct file *file, const char __user *buf, | |
f9ce299f | 118 | size_t count, loff_t *ppos) |
1da177e4 | 119 | { |
f9ce299f AB |
120 | ssize_t ret; |
121 | char *tmp = NULL; | |
122 | ssize_t size; | |
1da177e4 | 123 | |
f9ce299f AB |
124 | ret = -ENODEV; |
125 | if (!ppc_md.nvram_size) | |
126 | goto out; | |
127 | ||
128 | ret = 0; | |
1da177e4 | 129 | size = ppc_md.nvram_size(); |
f9ce299f AB |
130 | if (*ppos >= size || size < 0) |
131 | goto out; | |
1da177e4 | 132 | |
f9ce299f AB |
133 | count = min_t(size_t, count, size - *ppos); |
134 | count = min(count, PAGE_SIZE); | |
1da177e4 | 135 | |
f9ce299f AB |
136 | ret = -ENOMEM; |
137 | tmp = kmalloc(count, GFP_KERNEL); | |
138 | if (!tmp) | |
139 | goto out; | |
140 | ||
141 | ret = -EFAULT; | |
142 | if (copy_from_user(tmp, buf, count)) | |
143 | goto out; | |
144 | ||
145 | ret = ppc_md.nvram_write(tmp, count, ppos); | |
146 | ||
147 | out: | |
148 | kfree(tmp); | |
149 | return ret; | |
1da177e4 | 150 | |
1da177e4 LT |
151 | } |
152 | ||
153 | static int dev_nvram_ioctl(struct inode *inode, struct file *file, | |
154 | unsigned int cmd, unsigned long arg) | |
155 | { | |
156 | switch(cmd) { | |
157 | #ifdef CONFIG_PPC_PMAC | |
158 | case OBSOLETE_PMAC_NVRAM_GET_OFFSET: | |
159 | printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); | |
160 | case IOC_NVRAM_GET_OFFSET: { | |
161 | int part, offset; | |
162 | ||
e8222502 | 163 | if (!machine_is(powermac)) |
1da177e4 LT |
164 | return -EINVAL; |
165 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
166 | return -EFAULT; | |
167 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
168 | return -EINVAL; | |
169 | offset = pmac_get_partition(part); | |
170 | if (offset < 0) | |
171 | return offset; | |
172 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
173 | return -EFAULT; | |
174 | return 0; | |
175 | } | |
176 | #endif /* CONFIG_PPC_PMAC */ | |
af308377 SR |
177 | default: |
178 | return -EINVAL; | |
1da177e4 | 179 | } |
1da177e4 LT |
180 | } |
181 | ||
182 | struct file_operations nvram_fops = { | |
183 | .owner = THIS_MODULE, | |
184 | .llseek = dev_nvram_llseek, | |
185 | .read = dev_nvram_read, | |
186 | .write = dev_nvram_write, | |
187 | .ioctl = dev_nvram_ioctl, | |
188 | }; | |
189 | ||
190 | static struct miscdevice nvram_dev = { | |
191 | NVRAM_MINOR, | |
192 | "nvram", | |
193 | &nvram_fops | |
194 | }; | |
195 | ||
196 | ||
197 | #ifdef DEBUG_NVRAM | |
198 | static void nvram_print_partitions(char * label) | |
199 | { | |
200 | struct list_head * p; | |
201 | struct nvram_partition * tmp_part; | |
202 | ||
203 | printk(KERN_WARNING "--------%s---------\n", label); | |
204 | printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n"); | |
205 | list_for_each(p, &nvram_part->partition) { | |
206 | tmp_part = list_entry(p, struct nvram_partition, partition); | |
5a43ee65 | 207 | printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%s\n", |
1da177e4 LT |
208 | tmp_part->index, tmp_part->header.signature, |
209 | tmp_part->header.checksum, tmp_part->header.length, | |
210 | tmp_part->header.name); | |
211 | } | |
212 | } | |
213 | #endif | |
214 | ||
215 | ||
216 | static int nvram_write_header(struct nvram_partition * part) | |
217 | { | |
218 | loff_t tmp_index; | |
219 | int rc; | |
220 | ||
221 | tmp_index = part->index; | |
222 | rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index); | |
223 | ||
224 | return rc; | |
225 | } | |
226 | ||
227 | ||
228 | static unsigned char nvram_checksum(struct nvram_header *p) | |
229 | { | |
230 | unsigned int c_sum, c_sum2; | |
231 | unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */ | |
232 | c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5]; | |
233 | ||
234 | /* The sum may have spilled into the 3rd byte. Fold it back. */ | |
235 | c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff; | |
236 | /* The sum cannot exceed 2 bytes. Fold it into a checksum */ | |
237 | c_sum2 = (c_sum >> 8) + (c_sum << 8); | |
238 | c_sum = ((c_sum + c_sum2) >> 8) & 0xff; | |
239 | return c_sum; | |
240 | } | |
241 | ||
242 | ||
243 | /* | |
244 | * Find an nvram partition, sig can be 0 for any | |
245 | * partition or name can be NULL for any name, else | |
246 | * tries to match both | |
247 | */ | |
248 | struct nvram_partition *nvram_find_partition(int sig, const char *name) | |
249 | { | |
250 | struct nvram_partition * part; | |
251 | struct list_head * p; | |
252 | ||
253 | list_for_each(p, &nvram_part->partition) { | |
254 | part = list_entry(p, struct nvram_partition, partition); | |
255 | ||
256 | if (sig && part->header.signature != sig) | |
257 | continue; | |
258 | if (name && 0 != strncmp(name, part->header.name, 12)) | |
259 | continue; | |
260 | return part; | |
261 | } | |
262 | return NULL; | |
263 | } | |
264 | EXPORT_SYMBOL(nvram_find_partition); | |
265 | ||
266 | ||
267 | static int nvram_remove_os_partition(void) | |
268 | { | |
269 | struct list_head *i; | |
270 | struct list_head *j; | |
271 | struct nvram_partition * part; | |
272 | struct nvram_partition * cur_part; | |
273 | int rc; | |
274 | ||
275 | list_for_each(i, &nvram_part->partition) { | |
276 | part = list_entry(i, struct nvram_partition, partition); | |
277 | if (part->header.signature != NVRAM_SIG_OS) | |
278 | continue; | |
279 | ||
280 | /* Make os partition a free partition */ | |
281 | part->header.signature = NVRAM_SIG_FREE; | |
282 | sprintf(part->header.name, "wwwwwwwwwwww"); | |
283 | part->header.checksum = nvram_checksum(&part->header); | |
284 | ||
285 | /* Merge contiguous free partitions backwards */ | |
286 | list_for_each_prev(j, &part->partition) { | |
287 | cur_part = list_entry(j, struct nvram_partition, partition); | |
288 | if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { | |
289 | break; | |
290 | } | |
291 | ||
292 | part->header.length += cur_part->header.length; | |
293 | part->header.checksum = nvram_checksum(&part->header); | |
294 | part->index = cur_part->index; | |
295 | ||
296 | list_del(&cur_part->partition); | |
297 | kfree(cur_part); | |
298 | j = &part->partition; /* fixup our loop */ | |
299 | } | |
300 | ||
301 | /* Merge contiguous free partitions forwards */ | |
302 | list_for_each(j, &part->partition) { | |
303 | cur_part = list_entry(j, struct nvram_partition, partition); | |
304 | if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { | |
305 | break; | |
306 | } | |
307 | ||
308 | part->header.length += cur_part->header.length; | |
309 | part->header.checksum = nvram_checksum(&part->header); | |
310 | ||
311 | list_del(&cur_part->partition); | |
312 | kfree(cur_part); | |
313 | j = &part->partition; /* fixup our loop */ | |
314 | } | |
315 | ||
316 | rc = nvram_write_header(part); | |
317 | if (rc <= 0) { | |
318 | printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc); | |
319 | return rc; | |
320 | } | |
321 | ||
322 | } | |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
327 | /* nvram_create_os_partition | |
328 | * | |
329 | * Create a OS linux partition to buffer error logs. | |
330 | * Will create a partition starting at the first free | |
331 | * space found if space has enough room. | |
332 | */ | |
333 | static int nvram_create_os_partition(void) | |
334 | { | |
a341ad97 AB |
335 | struct nvram_partition *part; |
336 | struct nvram_partition *new_part; | |
0339ad77 | 337 | struct nvram_partition *free_part = NULL; |
1da177e4 LT |
338 | int seq_init[2] = { 0, 0 }; |
339 | loff_t tmp_index; | |
340 | long size = 0; | |
341 | int rc; | |
342 | ||
343 | /* Find a free partition that will give us the maximum needed size | |
344 | If can't find one that will give us the minimum size needed */ | |
a341ad97 | 345 | list_for_each_entry(part, &nvram_part->partition, partition) { |
1da177e4 LT |
346 | if (part->header.signature != NVRAM_SIG_FREE) |
347 | continue; | |
348 | ||
349 | if (part->header.length >= NVRAM_MAX_REQ) { | |
350 | size = NVRAM_MAX_REQ; | |
351 | free_part = part; | |
352 | break; | |
353 | } | |
354 | if (!size && part->header.length >= NVRAM_MIN_REQ) { | |
355 | size = NVRAM_MIN_REQ; | |
356 | free_part = part; | |
357 | } | |
358 | } | |
0339ad77 | 359 | if (!size) |
1da177e4 | 360 | return -ENOSPC; |
1da177e4 LT |
361 | |
362 | /* Create our OS partition */ | |
0339ad77 | 363 | new_part = kmalloc(sizeof(*new_part), GFP_KERNEL); |
1da177e4 LT |
364 | if (!new_part) { |
365 | printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n"); | |
366 | return -ENOMEM; | |
367 | } | |
368 | ||
369 | new_part->index = free_part->index; | |
370 | new_part->header.signature = NVRAM_SIG_OS; | |
371 | new_part->header.length = size; | |
0339ad77 | 372 | strcpy(new_part->header.name, "ppc64,linux"); |
1da177e4 LT |
373 | new_part->header.checksum = nvram_checksum(&new_part->header); |
374 | ||
375 | rc = nvram_write_header(new_part); | |
376 | if (rc <= 0) { | |
377 | printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \ | |
378 | failed (%d)\n", rc); | |
379 | return rc; | |
380 | } | |
381 | ||
382 | /* make sure and initialize to zero the sequence number and the error | |
383 | type logged */ | |
384 | tmp_index = new_part->index + NVRAM_HEADER_LEN; | |
385 | rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index); | |
386 | if (rc <= 0) { | |
0339ad77 | 387 | printk(KERN_ERR "nvram_create_os_partition: nvram_write " |
388 | "failed (%d)\n", rc); | |
1da177e4 LT |
389 | return rc; |
390 | } | |
391 | ||
392 | nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN; | |
393 | nvram_error_log_size = ((part->header.length - 1) * | |
394 | NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); | |
395 | ||
396 | list_add_tail(&new_part->partition, &free_part->partition); | |
397 | ||
398 | if (free_part->header.length <= size) { | |
399 | list_del(&free_part->partition); | |
400 | kfree(free_part); | |
401 | return 0; | |
402 | } | |
403 | ||
404 | /* Adjust the partition we stole the space from */ | |
405 | free_part->index += size * NVRAM_BLOCK_LEN; | |
406 | free_part->header.length -= size; | |
407 | free_part->header.checksum = nvram_checksum(&free_part->header); | |
408 | ||
409 | rc = nvram_write_header(free_part); | |
410 | if (rc <= 0) { | |
411 | printk(KERN_ERR "nvram_create_os_partition: nvram_write_header " | |
412 | "failed (%d)\n", rc); | |
413 | return rc; | |
414 | } | |
415 | ||
416 | return 0; | |
417 | } | |
418 | ||
419 | ||
420 | /* nvram_setup_partition | |
421 | * | |
422 | * This will setup the partition we need for buffering the | |
423 | * error logs and cleanup partitions if needed. | |
424 | * | |
425 | * The general strategy is the following: | |
426 | * 1.) If there is ppc64,linux partition large enough then use it. | |
427 | * 2.) If there is not a ppc64,linux partition large enough, search | |
428 | * for a free partition that is large enough. | |
429 | * 3.) If there is not a free partition large enough remove | |
430 | * _all_ OS partitions and consolidate the space. | |
431 | * 4.) Will first try getting a chunk that will satisfy the maximum | |
432 | * error log size (NVRAM_MAX_REQ). | |
433 | * 5.) If the max chunk cannot be allocated then try finding a chunk | |
434 | * that will satisfy the minum needed (NVRAM_MIN_REQ). | |
435 | */ | |
436 | static int nvram_setup_partition(void) | |
437 | { | |
438 | struct list_head * p; | |
439 | struct nvram_partition * part; | |
440 | int rc; | |
441 | ||
442 | /* For now, we don't do any of this on pmac, until I | |
443 | * have figured out if it's worth killing some unused stuffs | |
444 | * in our nvram, as Apple defined partitions use pretty much | |
445 | * all of the space | |
446 | */ | |
e8222502 | 447 | if (machine_is(powermac)) |
1da177e4 LT |
448 | return -ENOSPC; |
449 | ||
450 | /* see if we have an OS partition that meets our needs. | |
451 | will try getting the max we need. If not we'll delete | |
452 | partitions and try again. */ | |
453 | list_for_each(p, &nvram_part->partition) { | |
454 | part = list_entry(p, struct nvram_partition, partition); | |
455 | if (part->header.signature != NVRAM_SIG_OS) | |
456 | continue; | |
457 | ||
458 | if (strcmp(part->header.name, "ppc64,linux")) | |
459 | continue; | |
460 | ||
461 | if (part->header.length >= NVRAM_MIN_REQ) { | |
462 | /* found our partition */ | |
463 | nvram_error_log_index = part->index + NVRAM_HEADER_LEN; | |
464 | nvram_error_log_size = ((part->header.length - 1) * | |
465 | NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); | |
466 | return 0; | |
467 | } | |
468 | } | |
469 | ||
470 | /* try creating a partition with the free space we have */ | |
471 | rc = nvram_create_os_partition(); | |
472 | if (!rc) { | |
473 | return 0; | |
474 | } | |
475 | ||
476 | /* need to free up some space */ | |
477 | rc = nvram_remove_os_partition(); | |
478 | if (rc) { | |
479 | return rc; | |
480 | } | |
481 | ||
482 | /* create a partition in this new space */ | |
483 | rc = nvram_create_os_partition(); | |
484 | if (rc) { | |
485 | printk(KERN_ERR "nvram_create_os_partition: Could not find a " | |
486 | "NVRAM partition large enough\n"); | |
487 | return rc; | |
488 | } | |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
493 | ||
494 | static int nvram_scan_partitions(void) | |
495 | { | |
496 | loff_t cur_index = 0; | |
497 | struct nvram_header phead; | |
498 | struct nvram_partition * tmp_part; | |
499 | unsigned char c_sum; | |
500 | char * header; | |
501 | int total_size; | |
502 | int err; | |
503 | ||
504 | if (ppc_md.nvram_size == NULL) | |
505 | return -ENODEV; | |
506 | total_size = ppc_md.nvram_size(); | |
507 | ||
5cbded58 | 508 | header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL); |
1da177e4 LT |
509 | if (!header) { |
510 | printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n"); | |
511 | return -ENOMEM; | |
512 | } | |
513 | ||
514 | while (cur_index < total_size) { | |
515 | ||
516 | err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index); | |
517 | if (err != NVRAM_HEADER_LEN) { | |
518 | printk(KERN_ERR "nvram_scan_partitions: Error parsing " | |
519 | "nvram partitions\n"); | |
520 | goto out; | |
521 | } | |
522 | ||
523 | cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */ | |
524 | ||
525 | memcpy(&phead, header, NVRAM_HEADER_LEN); | |
526 | ||
527 | err = 0; | |
528 | c_sum = nvram_checksum(&phead); | |
529 | if (c_sum != phead.checksum) { | |
530 | printk(KERN_WARNING "WARNING: nvram partition checksum" | |
531 | " was %02x, should be %02x!\n", | |
532 | phead.checksum, c_sum); | |
533 | printk(KERN_WARNING "Terminating nvram partition scan\n"); | |
534 | goto out; | |
535 | } | |
536 | if (!phead.length) { | |
537 | printk(KERN_WARNING "WARNING: nvram corruption " | |
538 | "detected: 0-length partition\n"); | |
539 | goto out; | |
540 | } | |
541 | tmp_part = (struct nvram_partition *) | |
542 | kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); | |
543 | err = -ENOMEM; | |
544 | if (!tmp_part) { | |
545 | printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n"); | |
546 | goto out; | |
547 | } | |
548 | ||
549 | memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN); | |
550 | tmp_part->index = cur_index; | |
551 | list_add_tail(&tmp_part->partition, &nvram_part->partition); | |
552 | ||
553 | cur_index += phead.length * NVRAM_BLOCK_LEN; | |
554 | } | |
555 | err = 0; | |
556 | ||
557 | out: | |
558 | kfree(header); | |
559 | return err; | |
560 | } | |
561 | ||
562 | static int __init nvram_init(void) | |
563 | { | |
564 | int error; | |
565 | int rc; | |
566 | ||
567 | if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0) | |
568 | return -ENODEV; | |
569 | ||
570 | rc = misc_register(&nvram_dev); | |
571 | if (rc != 0) { | |
572 | printk(KERN_ERR "nvram_init: failed to register device\n"); | |
573 | return rc; | |
574 | } | |
575 | ||
576 | /* initialize our anchor for the nvram partition list */ | |
5cbded58 | 577 | nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); |
1da177e4 LT |
578 | if (!nvram_part) { |
579 | printk(KERN_ERR "nvram_init: Failed kmalloc\n"); | |
580 | return -ENOMEM; | |
581 | } | |
582 | INIT_LIST_HEAD(&nvram_part->partition); | |
583 | ||
584 | /* Get all the NVRAM partitions */ | |
585 | error = nvram_scan_partitions(); | |
586 | if (error) { | |
587 | printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n"); | |
588 | return error; | |
589 | } | |
590 | ||
591 | if(nvram_setup_partition()) | |
592 | printk(KERN_WARNING "nvram_init: Could not find nvram partition" | |
593 | " for nvram buffered error logging.\n"); | |
594 | ||
595 | #ifdef DEBUG_NVRAM | |
596 | nvram_print_partitions("NVRAM Partitions"); | |
597 | #endif | |
598 | ||
599 | return rc; | |
600 | } | |
601 | ||
602 | void __exit nvram_cleanup(void) | |
603 | { | |
604 | misc_deregister( &nvram_dev ); | |
605 | } | |
606 | ||
607 | ||
608 | #ifdef CONFIG_PPC_PSERIES | |
609 | ||
610 | /* nvram_write_error_log | |
611 | * | |
612 | * We need to buffer the error logs into nvram to ensure that we have | |
613 | * the failure information to decode. If we have a severe error there | |
614 | * is no way to guarantee that the OS or the machine is in a state to | |
615 | * get back to user land and write the error to disk. For example if | |
616 | * the SCSI device driver causes a Machine Check by writing to a bad | |
617 | * IO address, there is no way of guaranteeing that the device driver | |
618 | * is in any state that is would also be able to write the error data | |
619 | * captured to disk, thus we buffer it in NVRAM for analysis on the | |
620 | * next boot. | |
621 | * | |
622 | * In NVRAM the partition containing the error log buffer will looks like: | |
623 | * Header (in bytes): | |
624 | * +-----------+----------+--------+------------+------------------+ | |
625 | * | signature | checksum | length | name | data | | |
626 | * |0 |1 |2 3|4 15|16 length-1| | |
627 | * +-----------+----------+--------+------------+------------------+ | |
628 | * | |
629 | * The 'data' section would look like (in bytes): | |
630 | * +--------------+------------+-----------------------------------+ | |
631 | * | event_logged | sequence # | error log | | |
632 | * |0 3|4 7|8 nvram_error_log_size-1| | |
633 | * +--------------+------------+-----------------------------------+ | |
634 | * | |
635 | * event_logged: 0 if event has not been logged to syslog, 1 if it has | |
636 | * sequence #: The unique sequence # for each event. (until it wraps) | |
637 | * error log: The error log from event_scan | |
638 | */ | |
639 | int nvram_write_error_log(char * buff, int length, unsigned int err_type) | |
640 | { | |
641 | int rc; | |
642 | loff_t tmp_index; | |
643 | struct err_log_info info; | |
644 | ||
645 | if (no_logging) { | |
646 | return -EPERM; | |
647 | } | |
648 | ||
649 | if (nvram_error_log_index == -1) { | |
650 | return -ESPIPE; | |
651 | } | |
652 | ||
653 | if (length > nvram_error_log_size) { | |
654 | length = nvram_error_log_size; | |
655 | } | |
656 | ||
657 | info.error_type = err_type; | |
658 | info.seq_num = error_log_cnt; | |
659 | ||
660 | tmp_index = nvram_error_log_index; | |
661 | ||
662 | rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index); | |
663 | if (rc <= 0) { | |
664 | printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); | |
665 | return rc; | |
666 | } | |
667 | ||
668 | rc = ppc_md.nvram_write(buff, length, &tmp_index); | |
669 | if (rc <= 0) { | |
670 | printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); | |
671 | return rc; | |
672 | } | |
673 | ||
674 | return 0; | |
675 | } | |
676 | ||
677 | /* nvram_read_error_log | |
678 | * | |
679 | * Reads nvram for error log for at most 'length' | |
680 | */ | |
681 | int nvram_read_error_log(char * buff, int length, unsigned int * err_type) | |
682 | { | |
683 | int rc; | |
684 | loff_t tmp_index; | |
685 | struct err_log_info info; | |
686 | ||
687 | if (nvram_error_log_index == -1) | |
688 | return -1; | |
689 | ||
690 | if (length > nvram_error_log_size) | |
691 | length = nvram_error_log_size; | |
692 | ||
693 | tmp_index = nvram_error_log_index; | |
694 | ||
695 | rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index); | |
696 | if (rc <= 0) { | |
697 | printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); | |
698 | return rc; | |
699 | } | |
700 | ||
701 | rc = ppc_md.nvram_read(buff, length, &tmp_index); | |
702 | if (rc <= 0) { | |
703 | printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); | |
704 | return rc; | |
705 | } | |
706 | ||
707 | error_log_cnt = info.seq_num; | |
708 | *err_type = info.error_type; | |
709 | ||
710 | return 0; | |
711 | } | |
712 | ||
713 | /* This doesn't actually zero anything, but it sets the event_logged | |
714 | * word to tell that this event is safely in syslog. | |
715 | */ | |
716 | int nvram_clear_error_log(void) | |
717 | { | |
718 | loff_t tmp_index; | |
719 | int clear_word = ERR_FLAG_ALREADY_LOGGED; | |
720 | int rc; | |
721 | ||
722 | tmp_index = nvram_error_log_index; | |
723 | ||
724 | rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index); | |
725 | if (rc <= 0) { | |
726 | printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); | |
727 | return rc; | |
728 | } | |
729 | ||
730 | return 0; | |
731 | } | |
732 | ||
733 | #endif /* CONFIG_PPC_PSERIES */ | |
734 | ||
735 | module_init(nvram_init); | |
736 | module_exit(nvram_cleanup); | |
737 | MODULE_LICENSE("GPL"); |