2 * c 2001 PPC 64 Team, IBM Corp
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.
9 * /dev/nvram driver for PPC64
11 * This perhaps should live in drivers/char
13 * TODO: Split the /dev/nvram part (that one can use
14 * drivers/char/generic_nvram.c) from the arch & partition
18 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/errno.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>
33 #include <asm/machdep.h>
34 #include <asm/systemcfg.h>
38 static int nvram_scan_partitions(void);
39 static int nvram_setup_partition(void);
40 static int nvram_create_os_partition(void);
41 static int nvram_remove_os_partition(void);
43 static struct nvram_partition * nvram_part;
44 static long nvram_error_log_index = -1;
45 static long nvram_error_log_size = 0;
47 int no_logging = 1; /* Until we initialize everything,
48 * make sure we don't try logging
51 extern volatile int error_log_cnt;
58 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
62 if (ppc_md.nvram_size == NULL)
64 size = ppc_md.nvram_size();
68 offset += file->f_pos;
81 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
82 size_t count, loff_t *ppos)
88 if (ppc_md.nvram_size == NULL)
90 size = ppc_md.nvram_size();
92 if (!access_ok(VERIFY_WRITE, buf, count))
99 tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
101 printk(KERN_ERR "dev_read_nvram: kmalloc failed\n");
105 len = ppc_md.nvram_read(tmp_buffer, count, ppos);
106 if ((long)len <= 0) {
111 if (copy_to_user(buf, tmp_buffer, len)) {
121 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
122 size_t count, loff_t *ppos)
128 if (ppc_md.nvram_size == NULL)
130 size = ppc_md.nvram_size();
132 if (!access_ok(VERIFY_READ, buf, count))
139 tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
141 printk(KERN_ERR "dev_nvram_write: kmalloc failed\n");
145 if (copy_from_user(tmp_buffer, buf, count)) {
150 len = ppc_md.nvram_write(tmp_buffer, count, ppos);
151 if ((long)len <= 0) {
160 static int dev_nvram_ioctl(struct inode *inode, struct file *file,
161 unsigned int cmd, unsigned long arg)
164 #ifdef CONFIG_PPC_PMAC
165 case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
166 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
167 case IOC_NVRAM_GET_OFFSET: {
170 if (systemcfg->platform != PLATFORM_POWERMAC)
172 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
174 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
176 offset = pmac_get_partition(part);
179 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
183 #endif /* CONFIG_PPC_PMAC */
188 struct file_operations nvram_fops = {
189 .owner = THIS_MODULE,
190 .llseek = dev_nvram_llseek,
191 .read = dev_nvram_read,
192 .write = dev_nvram_write,
193 .ioctl = dev_nvram_ioctl,
196 static struct miscdevice nvram_dev = {
204 static void nvram_print_partitions(char * label)
206 struct list_head * p;
207 struct nvram_partition * tmp_part;
209 printk(KERN_WARNING "--------%s---------\n", label);
210 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
211 list_for_each(p, &nvram_part->partition) {
212 tmp_part = list_entry(p, struct nvram_partition, partition);
213 printk(KERN_WARNING "%d \t%02x\t%02x\t%d\t%s\n",
214 tmp_part->index, tmp_part->header.signature,
215 tmp_part->header.checksum, tmp_part->header.length,
216 tmp_part->header.name);
222 static int nvram_write_header(struct nvram_partition * part)
227 tmp_index = part->index;
228 rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
234 static unsigned char nvram_checksum(struct nvram_header *p)
236 unsigned int c_sum, c_sum2;
237 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
238 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
240 /* The sum may have spilled into the 3rd byte. Fold it back. */
241 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
242 /* The sum cannot exceed 2 bytes. Fold it into a checksum */
243 c_sum2 = (c_sum >> 8) + (c_sum << 8);
244 c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
250 * Find an nvram partition, sig can be 0 for any
251 * partition or name can be NULL for any name, else
252 * tries to match both
254 struct nvram_partition *nvram_find_partition(int sig, const char *name)
256 struct nvram_partition * part;
257 struct list_head * p;
259 list_for_each(p, &nvram_part->partition) {
260 part = list_entry(p, struct nvram_partition, partition);
262 if (sig && part->header.signature != sig)
264 if (name && 0 != strncmp(name, part->header.name, 12))
270 EXPORT_SYMBOL(nvram_find_partition);
273 static int nvram_remove_os_partition(void)
277 struct nvram_partition * part;
278 struct nvram_partition * cur_part;
281 list_for_each(i, &nvram_part->partition) {
282 part = list_entry(i, struct nvram_partition, partition);
283 if (part->header.signature != NVRAM_SIG_OS)
286 /* Make os partition a free partition */
287 part->header.signature = NVRAM_SIG_FREE;
288 sprintf(part->header.name, "wwwwwwwwwwww");
289 part->header.checksum = nvram_checksum(&part->header);
291 /* Merge contiguous free partitions backwards */
292 list_for_each_prev(j, &part->partition) {
293 cur_part = list_entry(j, struct nvram_partition, partition);
294 if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
298 part->header.length += cur_part->header.length;
299 part->header.checksum = nvram_checksum(&part->header);
300 part->index = cur_part->index;
302 list_del(&cur_part->partition);
304 j = &part->partition; /* fixup our loop */
307 /* Merge contiguous free partitions forwards */
308 list_for_each(j, &part->partition) {
309 cur_part = list_entry(j, struct nvram_partition, partition);
310 if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
314 part->header.length += cur_part->header.length;
315 part->header.checksum = nvram_checksum(&part->header);
317 list_del(&cur_part->partition);
319 j = &part->partition; /* fixup our loop */
322 rc = nvram_write_header(part);
324 printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
333 /* nvram_create_os_partition
335 * Create a OS linux partition to buffer error logs.
336 * Will create a partition starting at the first free
337 * space found if space has enough room.
339 static int nvram_create_os_partition(void)
341 struct list_head * p;
342 struct nvram_partition * part;
343 struct nvram_partition * new_part = NULL;
344 struct nvram_partition * free_part = NULL;
345 int seq_init[2] = { 0, 0 };
350 /* Find a free partition that will give us the maximum needed size
351 If can't find one that will give us the minimum size needed */
352 list_for_each(p, &nvram_part->partition) {
353 part = list_entry(p, struct nvram_partition, partition);
354 if (part->header.signature != NVRAM_SIG_FREE)
357 if (part->header.length >= NVRAM_MAX_REQ) {
358 size = NVRAM_MAX_REQ;
362 if (!size && part->header.length >= NVRAM_MIN_REQ) {
363 size = NVRAM_MIN_REQ;
371 /* Create our OS partition */
372 new_part = (struct nvram_partition *)
373 kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
375 printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
379 new_part->index = free_part->index;
380 new_part->header.signature = NVRAM_SIG_OS;
381 new_part->header.length = size;
382 sprintf(new_part->header.name, "ppc64,linux");
383 new_part->header.checksum = nvram_checksum(&new_part->header);
385 rc = nvram_write_header(new_part);
387 printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \
392 /* make sure and initialize to zero the sequence number and the error
394 tmp_index = new_part->index + NVRAM_HEADER_LEN;
395 rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
397 printk(KERN_ERR "nvram_create_os_partition: nvram_write failed (%d)\n", rc);
401 nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
402 nvram_error_log_size = ((part->header.length - 1) *
403 NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
405 list_add_tail(&new_part->partition, &free_part->partition);
407 if (free_part->header.length <= size) {
408 list_del(&free_part->partition);
413 /* Adjust the partition we stole the space from */
414 free_part->index += size * NVRAM_BLOCK_LEN;
415 free_part->header.length -= size;
416 free_part->header.checksum = nvram_checksum(&free_part->header);
418 rc = nvram_write_header(free_part);
420 printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
421 "failed (%d)\n", rc);
429 /* nvram_setup_partition
431 * This will setup the partition we need for buffering the
432 * error logs and cleanup partitions if needed.
434 * The general strategy is the following:
435 * 1.) If there is ppc64,linux partition large enough then use it.
436 * 2.) If there is not a ppc64,linux partition large enough, search
437 * for a free partition that is large enough.
438 * 3.) If there is not a free partition large enough remove
439 * _all_ OS partitions and consolidate the space.
440 * 4.) Will first try getting a chunk that will satisfy the maximum
441 * error log size (NVRAM_MAX_REQ).
442 * 5.) If the max chunk cannot be allocated then try finding a chunk
443 * that will satisfy the minum needed (NVRAM_MIN_REQ).
445 static int nvram_setup_partition(void)
447 struct list_head * p;
448 struct nvram_partition * part;
451 /* For now, we don't do any of this on pmac, until I
452 * have figured out if it's worth killing some unused stuffs
453 * in our nvram, as Apple defined partitions use pretty much
456 if (systemcfg->platform == PLATFORM_POWERMAC)
459 /* see if we have an OS partition that meets our needs.
460 will try getting the max we need. If not we'll delete
461 partitions and try again. */
462 list_for_each(p, &nvram_part->partition) {
463 part = list_entry(p, struct nvram_partition, partition);
464 if (part->header.signature != NVRAM_SIG_OS)
467 if (strcmp(part->header.name, "ppc64,linux"))
470 if (part->header.length >= NVRAM_MIN_REQ) {
471 /* found our partition */
472 nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
473 nvram_error_log_size = ((part->header.length - 1) *
474 NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
479 /* try creating a partition with the free space we have */
480 rc = nvram_create_os_partition();
485 /* need to free up some space */
486 rc = nvram_remove_os_partition();
491 /* create a partition in this new space */
492 rc = nvram_create_os_partition();
494 printk(KERN_ERR "nvram_create_os_partition: Could not find a "
495 "NVRAM partition large enough\n");
503 static int nvram_scan_partitions(void)
505 loff_t cur_index = 0;
506 struct nvram_header phead;
507 struct nvram_partition * tmp_part;
513 if (ppc_md.nvram_size == NULL)
515 total_size = ppc_md.nvram_size();
517 header = (char *) kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
519 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
523 while (cur_index < total_size) {
525 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
526 if (err != NVRAM_HEADER_LEN) {
527 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
528 "nvram partitions\n");
532 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
534 memcpy(&phead, header, NVRAM_HEADER_LEN);
537 c_sum = nvram_checksum(&phead);
538 if (c_sum != phead.checksum) {
539 printk(KERN_WARNING "WARNING: nvram partition checksum"
540 " was %02x, should be %02x!\n",
541 phead.checksum, c_sum);
542 printk(KERN_WARNING "Terminating nvram partition scan\n");
546 printk(KERN_WARNING "WARNING: nvram corruption "
547 "detected: 0-length partition\n");
550 tmp_part = (struct nvram_partition *)
551 kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
554 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
558 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
559 tmp_part->index = cur_index;
560 list_add_tail(&tmp_part->partition, &nvram_part->partition);
562 cur_index += phead.length * NVRAM_BLOCK_LEN;
571 static int __init nvram_init(void)
576 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
579 rc = misc_register(&nvram_dev);
581 printk(KERN_ERR "nvram_init: failed to register device\n");
585 /* initialize our anchor for the nvram partition list */
586 nvram_part = (struct nvram_partition *) kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
588 printk(KERN_ERR "nvram_init: Failed kmalloc\n");
591 INIT_LIST_HEAD(&nvram_part->partition);
593 /* Get all the NVRAM partitions */
594 error = nvram_scan_partitions();
596 printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
600 if(nvram_setup_partition())
601 printk(KERN_WARNING "nvram_init: Could not find nvram partition"
602 " for nvram buffered error logging.\n");
605 nvram_print_partitions("NVRAM Partitions");
611 void __exit nvram_cleanup(void)
613 misc_deregister( &nvram_dev );
617 #ifdef CONFIG_PPC_PSERIES
619 /* nvram_write_error_log
621 * We need to buffer the error logs into nvram to ensure that we have
622 * the failure information to decode. If we have a severe error there
623 * is no way to guarantee that the OS or the machine is in a state to
624 * get back to user land and write the error to disk. For example if
625 * the SCSI device driver causes a Machine Check by writing to a bad
626 * IO address, there is no way of guaranteeing that the device driver
627 * is in any state that is would also be able to write the error data
628 * captured to disk, thus we buffer it in NVRAM for analysis on the
631 * In NVRAM the partition containing the error log buffer will looks like:
633 * +-----------+----------+--------+------------+------------------+
634 * | signature | checksum | length | name | data |
635 * |0 |1 |2 3|4 15|16 length-1|
636 * +-----------+----------+--------+------------+------------------+
638 * The 'data' section would look like (in bytes):
639 * +--------------+------------+-----------------------------------+
640 * | event_logged | sequence # | error log |
641 * |0 3|4 7|8 nvram_error_log_size-1|
642 * +--------------+------------+-----------------------------------+
644 * event_logged: 0 if event has not been logged to syslog, 1 if it has
645 * sequence #: The unique sequence # for each event. (until it wraps)
646 * error log: The error log from event_scan
648 int nvram_write_error_log(char * buff, int length, unsigned int err_type)
652 struct err_log_info info;
658 if (nvram_error_log_index == -1) {
662 if (length > nvram_error_log_size) {
663 length = nvram_error_log_size;
666 info.error_type = err_type;
667 info.seq_num = error_log_cnt;
669 tmp_index = nvram_error_log_index;
671 rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
673 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
677 rc = ppc_md.nvram_write(buff, length, &tmp_index);
679 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
686 /* nvram_read_error_log
688 * Reads nvram for error log for at most 'length'
690 int nvram_read_error_log(char * buff, int length, unsigned int * err_type)
694 struct err_log_info info;
696 if (nvram_error_log_index == -1)
699 if (length > nvram_error_log_size)
700 length = nvram_error_log_size;
702 tmp_index = nvram_error_log_index;
704 rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
706 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
710 rc = ppc_md.nvram_read(buff, length, &tmp_index);
712 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
716 error_log_cnt = info.seq_num;
717 *err_type = info.error_type;
722 /* This doesn't actually zero anything, but it sets the event_logged
723 * word to tell that this event is safely in syslog.
725 int nvram_clear_error_log(void)
728 int clear_word = ERR_FLAG_ALREADY_LOGGED;
731 tmp_index = nvram_error_log_index;
733 rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
735 printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
742 #endif /* CONFIG_PPC_PSERIES */
744 module_init(nvram_init);
745 module_exit(nvram_cleanup);
746 MODULE_LICENSE("GPL");