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>
37 #define NVRAM_HEADER_LEN sizeof(struct nvram_header)
38 #define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
39 #define NVRAM_MAX_REQ 2079
40 #define NVRAM_MIN_REQ 1055
42 /* If change this size, then change the size of NVNAME_LEN */
44 unsigned char signature;
45 unsigned char checksum;
46 unsigned short length;
50 struct nvram_partition {
51 struct list_head partition;
52 struct nvram_header header;
56 static struct nvram_partition * nvram_part;
57 static long nvram_error_log_index = -1;
58 static long nvram_error_log_size = 0;
65 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
69 if (ppc_md.nvram_size == NULL)
71 size = ppc_md.nvram_size();
75 offset += file->f_pos;
88 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
89 size_t count, loff_t *ppos)
96 if (!ppc_md.nvram_size)
100 size = ppc_md.nvram_size();
101 if (*ppos >= size || size < 0)
104 count = min_t(size_t, count, size - *ppos);
105 count = min(count, PAGE_SIZE);
108 tmp = kmalloc(count, GFP_KERNEL);
112 ret = ppc_md.nvram_read(tmp, count, ppos);
116 if (copy_to_user(buf, tmp, ret))
125 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
126 size_t count, loff_t *ppos)
133 if (!ppc_md.nvram_size)
137 size = ppc_md.nvram_size();
138 if (*ppos >= size || size < 0)
141 count = min_t(size_t, count, size - *ppos);
142 count = min(count, PAGE_SIZE);
145 tmp = kmalloc(count, GFP_KERNEL);
150 if (copy_from_user(tmp, buf, count))
153 ret = ppc_md.nvram_write(tmp, count, ppos);
161 static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
165 #ifdef CONFIG_PPC_PMAC
166 case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
167 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
168 case IOC_NVRAM_GET_OFFSET: {
171 if (!machine_is(powermac))
173 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
175 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
177 offset = pmac_get_partition(part);
180 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
184 #endif /* CONFIG_PPC_PMAC */
190 const struct file_operations nvram_fops = {
191 .owner = THIS_MODULE,
192 .llseek = dev_nvram_llseek,
193 .read = dev_nvram_read,
194 .write = dev_nvram_write,
195 .unlocked_ioctl = dev_nvram_ioctl,
198 static struct miscdevice nvram_dev = {
206 static void __init nvram_print_partitions(char * label)
208 struct list_head * p;
209 struct nvram_partition * tmp_part;
211 printk(KERN_WARNING "--------%s---------\n", label);
212 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
213 list_for_each(p, &nvram_part->partition) {
214 tmp_part = list_entry(p, struct nvram_partition, partition);
215 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%s\n",
216 tmp_part->index, tmp_part->header.signature,
217 tmp_part->header.checksum, tmp_part->header.length,
218 tmp_part->header.name);
224 static int __init nvram_write_header(struct nvram_partition * part)
229 tmp_index = part->index;
230 rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
236 static unsigned char __init nvram_checksum(struct nvram_header *p)
238 unsigned int c_sum, c_sum2;
239 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
240 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
242 /* The sum may have spilled into the 3rd byte. Fold it back. */
243 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
244 /* The sum cannot exceed 2 bytes. Fold it into a checksum */
245 c_sum2 = (c_sum >> 8) + (c_sum << 8);
246 c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
251 * nvram_remove_partition - Remove one or more partitions in nvram
252 * @name: name of the partition to remove, or NULL for a
253 * signature only match
254 * @sig: signature of the partition(s) to remove
257 static int __init nvram_remove_partition(const char *name, int sig)
259 struct nvram_partition *part, *prev, *tmp;
262 list_for_each_entry(part, &nvram_part->partition, partition) {
263 if (part->header.signature != sig)
265 if (name && strncmp(name, part->header.name, 12))
268 /* Make partition a free partition */
269 part->header.signature = NVRAM_SIG_FREE;
270 sprintf(part->header.name, "wwwwwwwwwwww");
271 part->header.checksum = nvram_checksum(&part->header);
272 rc = nvram_write_header(part);
274 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
279 /* Merge contiguous ones */
281 list_for_each_entry_safe(part, tmp, &nvram_part->partition, partition) {
282 if (part->header.signature != NVRAM_SIG_FREE) {
287 prev->header.length += part->header.length;
288 prev->header.checksum = nvram_checksum(&part->header);
289 rc = nvram_write_header(part);
291 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
294 list_del(&part->partition);
304 * nvram_create_partition - Create a partition in nvram
305 * @name: name of the partition to create
306 * @sig: signature of the partition to create
307 * @req_size: size of data to allocate in bytes
308 * @min_size: minimum acceptable size (0 means req_size)
310 * Returns a negative error code or a positive nvram index
311 * of the beginning of the data area of the newly created
312 * partition. If you provided a min_size smaller than req_size
313 * you need to query for the actual size yourself after the
314 * call using nvram_partition_get_size().
316 static loff_t __init nvram_create_partition(const char *name, int sig,
317 int req_size, int min_size)
319 struct nvram_partition *part;
320 struct nvram_partition *new_part;
321 struct nvram_partition *free_part = NULL;
322 static char nv_init_vals[16];
327 /* Convert sizes from bytes to blocks */
328 req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
329 min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
331 /* If no minimum size specified, make it the same as the
336 if (min_size > req_size)
339 /* Now add one block to each for the header */
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 */
345 list_for_each_entry(part, &nvram_part->partition, partition) {
346 if (part->header.signature != NVRAM_SIG_FREE)
349 if (part->header.length >= req_size) {
354 if (part->header.length > size &&
355 part->header.length >= min_size) {
356 size = part->header.length;
363 /* Create our OS partition */
364 new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
366 pr_err("nvram_create_os_partition: kmalloc failed\n");
370 new_part->index = free_part->index;
371 new_part->header.signature = sig;
372 new_part->header.length = size;
373 strncpy(new_part->header.name, name, 12);
374 new_part->header.checksum = nvram_checksum(&new_part->header);
376 rc = nvram_write_header(new_part);
378 pr_err("nvram_create_os_partition: nvram_write_header "
379 "failed (%d)\n", rc);
382 list_add_tail(&new_part->partition, &free_part->partition);
384 /* Adjust or remove the partition we stole the space from */
385 if (free_part->header.length > size) {
386 free_part->index += size * NVRAM_BLOCK_LEN;
387 free_part->header.length -= size;
388 free_part->header.checksum = nvram_checksum(&free_part->header);
389 rc = nvram_write_header(free_part);
391 pr_err("nvram_create_os_partition: nvram_write_header "
392 "failed (%d)\n", rc);
396 list_del(&free_part->partition);
400 /* Clear the new partition */
401 for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
402 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
403 tmp_index += NVRAM_BLOCK_LEN) {
404 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
406 pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
411 return new_part->index + NVRAM_HEADER_LEN;
415 * nvram_get_partition_size - Get the data size of an nvram partition
416 * @data_index: This is the offset of the start of the data of
417 * the partition. The same value that is returned by
418 * nvram_create_partition().
420 static int nvram_get_partition_size(loff_t data_index)
422 struct nvram_partition *part;
424 list_for_each_entry(part, &nvram_part->partition, partition) {
425 if (part->index + NVRAM_HEADER_LEN == data_index)
426 return (part->header.length - 1) * NVRAM_BLOCK_LEN;
433 * nvram_find_partition - Find an nvram partition by signature and name
434 * @name: Name of the partition or NULL for any name
435 * @sig: Signature to test against
436 * @out_size: if non-NULL, returns the size of the data part of the partition
438 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
440 struct nvram_partition *p;
442 list_for_each_entry(p, &nvram_part->partition, partition) {
443 if (p->header.signature == sig &&
444 (!name || !strncmp(p->header.name, name, 12))) {
446 *out_size = (p->header.length - 1) *
448 return p->index + NVRAM_HEADER_LEN;
454 /* nvram_setup_partition
456 * This will setup the partition we need for buffering the
457 * error logs and cleanup partitions if needed.
459 * The general strategy is the following:
460 * 1.) If there is ppc64,linux partition large enough then use it.
461 * 2.) If there is not a ppc64,linux partition large enough, search
462 * for a free partition that is large enough.
463 * 3.) If there is not a free partition large enough remove
464 * _all_ OS partitions and consolidate the space.
465 * 4.) Will first try getting a chunk that will satisfy the maximum
466 * error log size (NVRAM_MAX_REQ).
467 * 5.) If the max chunk cannot be allocated then try finding a chunk
468 * that will satisfy the minum needed (NVRAM_MIN_REQ).
470 static int __init nvram_setup_partition(void)
475 /* For now, we don't do any of this on pmac, until I
476 * have figured out if it's worth killing some unused stuffs
477 * in our nvram, as Apple defined partitions use pretty much
480 if (machine_is(powermac))
483 p = nvram_find_partition("ppc64,linux", NVRAM_SIG_OS, &size);
485 /* Found one but too small, remove it */
486 if (p && size < NVRAM_MIN_REQ) {
487 pr_info("nvram: Found too small ppc64,linux partition"
489 nvram_remove_partition("ppc64,linux", NVRAM_SIG_OS);
493 /* Create one if we didn't find */
495 p = nvram_create_partition("ppc64,linux", NVRAM_SIG_OS,
496 NVRAM_MAX_REQ, NVRAM_MIN_REQ);
497 /* No room for it, try to get rid of any OS partition
501 pr_info("nvram: No room to create ppc64,linux"
502 " partition, deleting all OS partitions...");
503 nvram_remove_partition(NULL, NVRAM_SIG_OS);
504 p = nvram_create_partition("ppc64,linux", NVRAM_SIG_OS,
505 NVRAM_MAX_REQ, NVRAM_MIN_REQ);
510 pr_err("nvram: Failed to find or create ppc64,linux"
511 " partition, err %d\n", (int)p);
515 nvram_error_log_index = p;
516 nvram_error_log_size = nvram_get_partition_size(p) -
517 sizeof(struct err_log_info);
522 static int __init nvram_scan_partitions(void)
524 loff_t cur_index = 0;
525 struct nvram_header phead;
526 struct nvram_partition * tmp_part;
532 if (ppc_md.nvram_size == NULL)
534 total_size = ppc_md.nvram_size();
536 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
538 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
542 while (cur_index < total_size) {
544 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
545 if (err != NVRAM_HEADER_LEN) {
546 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
547 "nvram partitions\n");
551 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
553 memcpy(&phead, header, NVRAM_HEADER_LEN);
556 c_sum = nvram_checksum(&phead);
557 if (c_sum != phead.checksum) {
558 printk(KERN_WARNING "WARNING: nvram partition checksum"
559 " was %02x, should be %02x!\n",
560 phead.checksum, c_sum);
561 printk(KERN_WARNING "Terminating nvram partition scan\n");
565 printk(KERN_WARNING "WARNING: nvram corruption "
566 "detected: 0-length partition\n");
569 tmp_part = (struct nvram_partition *)
570 kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
573 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
577 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
578 tmp_part->index = cur_index;
579 list_add_tail(&tmp_part->partition, &nvram_part->partition);
581 cur_index += phead.length * NVRAM_BLOCK_LEN;
590 static int __init nvram_init(void)
595 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
597 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
600 rc = misc_register(&nvram_dev);
602 printk(KERN_ERR "nvram_init: failed to register device\n");
606 /* initialize our anchor for the nvram partition list */
607 nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
609 printk(KERN_ERR "nvram_init: Failed kmalloc\n");
612 INIT_LIST_HEAD(&nvram_part->partition);
614 /* Get all the NVRAM partitions */
615 error = nvram_scan_partitions();
617 printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
621 if(nvram_setup_partition())
622 printk(KERN_WARNING "nvram_init: Could not find nvram partition"
623 " for nvram buffered error logging.\n");
626 nvram_print_partitions("NVRAM Partitions");
632 void __exit nvram_cleanup(void)
634 misc_deregister( &nvram_dev );
638 #ifdef CONFIG_PPC_PSERIES
640 /* nvram_write_error_log
642 * We need to buffer the error logs into nvram to ensure that we have
643 * the failure information to decode. If we have a severe error there
644 * is no way to guarantee that the OS or the machine is in a state to
645 * get back to user land and write the error to disk. For example if
646 * the SCSI device driver causes a Machine Check by writing to a bad
647 * IO address, there is no way of guaranteeing that the device driver
648 * is in any state that is would also be able to write the error data
649 * captured to disk, thus we buffer it in NVRAM for analysis on the
652 * In NVRAM the partition containing the error log buffer will looks like:
654 * +-----------+----------+--------+------------+------------------+
655 * | signature | checksum | length | name | data |
656 * |0 |1 |2 3|4 15|16 length-1|
657 * +-----------+----------+--------+------------+------------------+
659 * The 'data' section would look like (in bytes):
660 * +--------------+------------+-----------------------------------+
661 * | event_logged | sequence # | error log |
662 * |0 3|4 7|8 nvram_error_log_size-1|
663 * +--------------+------------+-----------------------------------+
665 * event_logged: 0 if event has not been logged to syslog, 1 if it has
666 * sequence #: The unique sequence # for each event. (until it wraps)
667 * error log: The error log from event_scan
669 int nvram_write_error_log(char * buff, int length,
670 unsigned int err_type, unsigned int error_log_cnt)
674 struct err_log_info info;
676 if (nvram_error_log_index == -1) {
680 if (length > nvram_error_log_size) {
681 length = nvram_error_log_size;
684 info.error_type = err_type;
685 info.seq_num = error_log_cnt;
687 tmp_index = nvram_error_log_index;
689 rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
691 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
695 rc = ppc_md.nvram_write(buff, length, &tmp_index);
697 printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
704 /* nvram_read_error_log
706 * Reads nvram for error log for at most 'length'
708 int nvram_read_error_log(char * buff, int length,
709 unsigned int * err_type, unsigned int * error_log_cnt)
713 struct err_log_info info;
715 if (nvram_error_log_index == -1)
718 if (length > nvram_error_log_size)
719 length = nvram_error_log_size;
721 tmp_index = nvram_error_log_index;
723 rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
725 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
729 rc = ppc_md.nvram_read(buff, length, &tmp_index);
731 printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
735 *error_log_cnt = info.seq_num;
736 *err_type = info.error_type;
741 /* This doesn't actually zero anything, but it sets the event_logged
742 * word to tell that this event is safely in syslog.
744 int nvram_clear_error_log(void)
747 int clear_word = ERR_FLAG_ALREADY_LOGGED;
750 if (nvram_error_log_index == -1)
753 tmp_index = nvram_error_log_index;
755 rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
757 printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
764 #endif /* CONFIG_PPC_PSERIES */
766 module_init(nvram_init);
767 module_exit(nvram_cleanup);
768 MODULE_LICENSE("GPL");