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 static struct nvram_partition
* nvram_part
;
38 static long nvram_error_log_index
= -1;
39 static long nvram_error_log_size
= 0;
46 static loff_t
dev_nvram_llseek(struct file
*file
, loff_t offset
, int origin
)
50 if (ppc_md
.nvram_size
== NULL
)
52 size
= ppc_md
.nvram_size();
56 offset
+= file
->f_pos
;
69 static ssize_t
dev_nvram_read(struct file
*file
, char __user
*buf
,
70 size_t count
, loff_t
*ppos
)
77 if (!ppc_md
.nvram_size
)
81 size
= ppc_md
.nvram_size();
82 if (*ppos
>= size
|| size
< 0)
85 count
= min_t(size_t, count
, size
- *ppos
);
86 count
= min(count
, PAGE_SIZE
);
89 tmp
= kmalloc(count
, GFP_KERNEL
);
93 ret
= ppc_md
.nvram_read(tmp
, count
, ppos
);
97 if (copy_to_user(buf
, tmp
, ret
))
106 static ssize_t
dev_nvram_write(struct file
*file
, const char __user
*buf
,
107 size_t count
, loff_t
*ppos
)
114 if (!ppc_md
.nvram_size
)
118 size
= ppc_md
.nvram_size();
119 if (*ppos
>= size
|| size
< 0)
122 count
= min_t(size_t, count
, size
- *ppos
);
123 count
= min(count
, PAGE_SIZE
);
126 tmp
= kmalloc(count
, GFP_KERNEL
);
131 if (copy_from_user(tmp
, buf
, count
))
134 ret
= ppc_md
.nvram_write(tmp
, count
, ppos
);
142 static long dev_nvram_ioctl(struct file
*file
, unsigned int 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
: {
152 if (!machine_is(powermac
))
154 if (copy_from_user(&part
, (void __user
*)arg
, sizeof(part
)) != 0)
156 if (part
< pmac_nvram_OF
|| part
> pmac_nvram_NR
)
158 offset
= pmac_get_partition(part
);
161 if (copy_to_user((void __user
*)arg
, &offset
, sizeof(offset
)) != 0)
165 #endif /* CONFIG_PPC_PMAC */
171 const struct file_operations nvram_fops
= {
172 .owner
= THIS_MODULE
,
173 .llseek
= dev_nvram_llseek
,
174 .read
= dev_nvram_read
,
175 .write
= dev_nvram_write
,
176 .unlocked_ioctl
= dev_nvram_ioctl
,
179 static struct miscdevice nvram_dev
= {
187 static void __init
nvram_print_partitions(char * label
)
189 struct list_head
* p
;
190 struct nvram_partition
* tmp_part
;
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
);
196 printk(KERN_WARNING
"%4d \t%02x\t%02x\t%d\t%s\n",
197 tmp_part
->index
, tmp_part
->header
.signature
,
198 tmp_part
->header
.checksum
, tmp_part
->header
.length
,
199 tmp_part
->header
.name
);
205 static int __init
nvram_write_header(struct nvram_partition
* part
)
210 tmp_index
= part
->index
;
211 rc
= ppc_md
.nvram_write((char *)&part
->header
, NVRAM_HEADER_LEN
, &tmp_index
);
217 static unsigned char __init
nvram_checksum(struct nvram_header
*p
)
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];
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;
231 static int __init
nvram_remove_os_partition(void)
235 struct nvram_partition
* part
;
236 struct nvram_partition
* cur_part
;
239 list_for_each(i
, &nvram_part
->partition
) {
240 part
= list_entry(i
, struct nvram_partition
, partition
);
241 if (part
->header
.signature
!= NVRAM_SIG_OS
)
244 /* Make os partition a free partition */
245 part
->header
.signature
= NVRAM_SIG_FREE
;
246 sprintf(part
->header
.name
, "wwwwwwwwwwww");
247 part
->header
.checksum
= nvram_checksum(&part
->header
);
249 /* Merge contiguous free partitions backwards */
250 list_for_each_prev(j
, &part
->partition
) {
251 cur_part
= list_entry(j
, struct nvram_partition
, partition
);
252 if (cur_part
== nvram_part
|| cur_part
->header
.signature
!= NVRAM_SIG_FREE
) {
256 part
->header
.length
+= cur_part
->header
.length
;
257 part
->header
.checksum
= nvram_checksum(&part
->header
);
258 part
->index
= cur_part
->index
;
260 list_del(&cur_part
->partition
);
262 j
= &part
->partition
; /* fixup our loop */
265 /* Merge contiguous free partitions forwards */
266 list_for_each(j
, &part
->partition
) {
267 cur_part
= list_entry(j
, struct nvram_partition
, partition
);
268 if (cur_part
== nvram_part
|| cur_part
->header
.signature
!= NVRAM_SIG_FREE
) {
272 part
->header
.length
+= cur_part
->header
.length
;
273 part
->header
.checksum
= nvram_checksum(&part
->header
);
275 list_del(&cur_part
->partition
);
277 j
= &part
->partition
; /* fixup our loop */
280 rc
= nvram_write_header(part
);
282 printk(KERN_ERR
"nvram_remove_os_partition: nvram_write failed (%d)\n", rc
);
291 /* nvram_create_os_partition
293 * Create a OS linux partition to buffer error logs.
294 * Will create a partition starting at the first free
295 * space found if space has enough room.
297 static int __init
nvram_create_os_partition(void)
299 struct nvram_partition
*part
;
300 struct nvram_partition
*new_part
;
301 struct nvram_partition
*free_part
= NULL
;
302 int seq_init
[2] = { 0, 0 };
307 /* Find a free partition that will give us the maximum needed size
308 If can't find one that will give us the minimum size needed */
309 list_for_each_entry(part
, &nvram_part
->partition
, partition
) {
310 if (part
->header
.signature
!= NVRAM_SIG_FREE
)
313 if (part
->header
.length
>= NVRAM_MAX_REQ
) {
314 size
= NVRAM_MAX_REQ
;
318 if (!size
&& part
->header
.length
>= NVRAM_MIN_REQ
) {
319 size
= NVRAM_MIN_REQ
;
326 /* Create our OS partition */
327 new_part
= kmalloc(sizeof(*new_part
), GFP_KERNEL
);
329 printk(KERN_ERR
"nvram_create_os_partition: kmalloc failed\n");
333 new_part
->index
= free_part
->index
;
334 new_part
->header
.signature
= NVRAM_SIG_OS
;
335 new_part
->header
.length
= size
;
336 strcpy(new_part
->header
.name
, "ppc64,linux");
337 new_part
->header
.checksum
= nvram_checksum(&new_part
->header
);
339 rc
= nvram_write_header(new_part
);
341 printk(KERN_ERR
"nvram_create_os_partition: nvram_write_header "
342 "failed (%d)\n", rc
);
346 /* make sure and initialize to zero the sequence number and the error
348 tmp_index
= new_part
->index
+ NVRAM_HEADER_LEN
;
349 rc
= ppc_md
.nvram_write((char *)&seq_init
, sizeof(seq_init
), &tmp_index
);
351 printk(KERN_ERR
"nvram_create_os_partition: nvram_write "
352 "failed (%d)\n", rc
);
356 nvram_error_log_index
= new_part
->index
+ NVRAM_HEADER_LEN
;
357 nvram_error_log_size
= ((part
->header
.length
- 1) *
358 NVRAM_BLOCK_LEN
) - sizeof(struct err_log_info
);
360 list_add_tail(&new_part
->partition
, &free_part
->partition
);
362 if (free_part
->header
.length
<= size
) {
363 list_del(&free_part
->partition
);
368 /* Adjust the partition we stole the space from */
369 free_part
->index
+= size
* NVRAM_BLOCK_LEN
;
370 free_part
->header
.length
-= size
;
371 free_part
->header
.checksum
= nvram_checksum(&free_part
->header
);
373 rc
= nvram_write_header(free_part
);
375 printk(KERN_ERR
"nvram_create_os_partition: nvram_write_header "
376 "failed (%d)\n", rc
);
384 /* nvram_setup_partition
386 * This will setup the partition we need for buffering the
387 * error logs and cleanup partitions if needed.
389 * The general strategy is the following:
390 * 1.) If there is ppc64,linux partition large enough then use it.
391 * 2.) If there is not a ppc64,linux partition large enough, search
392 * for a free partition that is large enough.
393 * 3.) If there is not a free partition large enough remove
394 * _all_ OS partitions and consolidate the space.
395 * 4.) Will first try getting a chunk that will satisfy the maximum
396 * error log size (NVRAM_MAX_REQ).
397 * 5.) If the max chunk cannot be allocated then try finding a chunk
398 * that will satisfy the minum needed (NVRAM_MIN_REQ).
400 static int __init
nvram_setup_partition(void)
402 struct list_head
* p
;
403 struct nvram_partition
* part
;
406 /* For now, we don't do any of this on pmac, until I
407 * have figured out if it's worth killing some unused stuffs
408 * in our nvram, as Apple defined partitions use pretty much
411 if (machine_is(powermac
))
414 /* see if we have an OS partition that meets our needs.
415 will try getting the max we need. If not we'll delete
416 partitions and try again. */
417 list_for_each(p
, &nvram_part
->partition
) {
418 part
= list_entry(p
, struct nvram_partition
, partition
);
419 if (part
->header
.signature
!= NVRAM_SIG_OS
)
422 if (strcmp(part
->header
.name
, "ppc64,linux"))
425 if (part
->header
.length
>= NVRAM_MIN_REQ
) {
426 /* found our partition */
427 nvram_error_log_index
= part
->index
+ NVRAM_HEADER_LEN
;
428 nvram_error_log_size
= ((part
->header
.length
- 1) *
429 NVRAM_BLOCK_LEN
) - sizeof(struct err_log_info
);
434 /* try creating a partition with the free space we have */
435 rc
= nvram_create_os_partition();
440 /* need to free up some space */
441 rc
= nvram_remove_os_partition();
446 /* create a partition in this new space */
447 rc
= nvram_create_os_partition();
449 printk(KERN_ERR
"nvram_create_os_partition: Could not find a "
450 "NVRAM partition large enough\n");
458 static int __init
nvram_scan_partitions(void)
460 loff_t cur_index
= 0;
461 struct nvram_header phead
;
462 struct nvram_partition
* tmp_part
;
468 if (ppc_md
.nvram_size
== NULL
)
470 total_size
= ppc_md
.nvram_size();
472 header
= kmalloc(NVRAM_HEADER_LEN
, GFP_KERNEL
);
474 printk(KERN_ERR
"nvram_scan_partitions: Failed kmalloc\n");
478 while (cur_index
< total_size
) {
480 err
= ppc_md
.nvram_read(header
, NVRAM_HEADER_LEN
, &cur_index
);
481 if (err
!= NVRAM_HEADER_LEN
) {
482 printk(KERN_ERR
"nvram_scan_partitions: Error parsing "
483 "nvram partitions\n");
487 cur_index
-= NVRAM_HEADER_LEN
; /* nvram_read will advance us */
489 memcpy(&phead
, header
, NVRAM_HEADER_LEN
);
492 c_sum
= nvram_checksum(&phead
);
493 if (c_sum
!= phead
.checksum
) {
494 printk(KERN_WARNING
"WARNING: nvram partition checksum"
495 " was %02x, should be %02x!\n",
496 phead
.checksum
, c_sum
);
497 printk(KERN_WARNING
"Terminating nvram partition scan\n");
501 printk(KERN_WARNING
"WARNING: nvram corruption "
502 "detected: 0-length partition\n");
505 tmp_part
= (struct nvram_partition
*)
506 kmalloc(sizeof(struct nvram_partition
), GFP_KERNEL
);
509 printk(KERN_ERR
"nvram_scan_partitions: kmalloc failed\n");
513 memcpy(&tmp_part
->header
, &phead
, NVRAM_HEADER_LEN
);
514 tmp_part
->index
= cur_index
;
515 list_add_tail(&tmp_part
->partition
, &nvram_part
->partition
);
517 cur_index
+= phead
.length
* NVRAM_BLOCK_LEN
;
526 static int __init
nvram_init(void)
531 if (ppc_md
.nvram_size
== NULL
|| ppc_md
.nvram_size() <= 0)
534 rc
= misc_register(&nvram_dev
);
536 printk(KERN_ERR
"nvram_init: failed to register device\n");
540 /* initialize our anchor for the nvram partition list */
541 nvram_part
= kmalloc(sizeof(struct nvram_partition
), GFP_KERNEL
);
543 printk(KERN_ERR
"nvram_init: Failed kmalloc\n");
546 INIT_LIST_HEAD(&nvram_part
->partition
);
548 /* Get all the NVRAM partitions */
549 error
= nvram_scan_partitions();
551 printk(KERN_ERR
"nvram_init: Failed nvram_scan_partitions\n");
555 if(nvram_setup_partition())
556 printk(KERN_WARNING
"nvram_init: Could not find nvram partition"
557 " for nvram buffered error logging.\n");
560 nvram_print_partitions("NVRAM Partitions");
566 void __exit
nvram_cleanup(void)
568 misc_deregister( &nvram_dev
);
572 #ifdef CONFIG_PPC_PSERIES
574 /* nvram_write_error_log
576 * We need to buffer the error logs into nvram to ensure that we have
577 * the failure information to decode. If we have a severe error there
578 * is no way to guarantee that the OS or the machine is in a state to
579 * get back to user land and write the error to disk. For example if
580 * the SCSI device driver causes a Machine Check by writing to a bad
581 * IO address, there is no way of guaranteeing that the device driver
582 * is in any state that is would also be able to write the error data
583 * captured to disk, thus we buffer it in NVRAM for analysis on the
586 * In NVRAM the partition containing the error log buffer will looks like:
588 * +-----------+----------+--------+------------+------------------+
589 * | signature | checksum | length | name | data |
590 * |0 |1 |2 3|4 15|16 length-1|
591 * +-----------+----------+--------+------------+------------------+
593 * The 'data' section would look like (in bytes):
594 * +--------------+------------+-----------------------------------+
595 * | event_logged | sequence # | error log |
596 * |0 3|4 7|8 nvram_error_log_size-1|
597 * +--------------+------------+-----------------------------------+
599 * event_logged: 0 if event has not been logged to syslog, 1 if it has
600 * sequence #: The unique sequence # for each event. (until it wraps)
601 * error log: The error log from event_scan
603 int nvram_write_error_log(char * buff
, int length
,
604 unsigned int err_type
, unsigned int error_log_cnt
)
608 struct err_log_info info
;
610 if (nvram_error_log_index
== -1) {
614 if (length
> nvram_error_log_size
) {
615 length
= nvram_error_log_size
;
618 info
.error_type
= err_type
;
619 info
.seq_num
= error_log_cnt
;
621 tmp_index
= nvram_error_log_index
;
623 rc
= ppc_md
.nvram_write((char *)&info
, sizeof(struct err_log_info
), &tmp_index
);
625 printk(KERN_ERR
"nvram_write_error_log: Failed nvram_write (%d)\n", rc
);
629 rc
= ppc_md
.nvram_write(buff
, length
, &tmp_index
);
631 printk(KERN_ERR
"nvram_write_error_log: Failed nvram_write (%d)\n", rc
);
638 /* nvram_read_error_log
640 * Reads nvram for error log for at most 'length'
642 int nvram_read_error_log(char * buff
, int length
,
643 unsigned int * err_type
, unsigned int * error_log_cnt
)
647 struct err_log_info info
;
649 if (nvram_error_log_index
== -1)
652 if (length
> nvram_error_log_size
)
653 length
= nvram_error_log_size
;
655 tmp_index
= nvram_error_log_index
;
657 rc
= ppc_md
.nvram_read((char *)&info
, sizeof(struct err_log_info
), &tmp_index
);
659 printk(KERN_ERR
"nvram_read_error_log: Failed nvram_read (%d)\n", rc
);
663 rc
= ppc_md
.nvram_read(buff
, length
, &tmp_index
);
665 printk(KERN_ERR
"nvram_read_error_log: Failed nvram_read (%d)\n", rc
);
669 *error_log_cnt
= info
.seq_num
;
670 *err_type
= info
.error_type
;
675 /* This doesn't actually zero anything, but it sets the event_logged
676 * word to tell that this event is safely in syslog.
678 int nvram_clear_error_log(void)
681 int clear_word
= ERR_FLAG_ALREADY_LOGGED
;
684 if (nvram_error_log_index
== -1)
687 tmp_index
= nvram_error_log_index
;
689 rc
= ppc_md
.nvram_write((char *)&clear_word
, sizeof(int), &tmp_index
);
691 printk(KERN_ERR
"nvram_clear_error_log: Failed nvram_write (%d)\n", rc
);
698 #endif /* CONFIG_PPC_PSERIES */
700 module_init(nvram_init
);
701 module_exit(nvram_cleanup
);
702 MODULE_LICENSE("GPL");