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
40 /* If change this size, then change the size of NVNAME_LEN */
42 unsigned char signature;
43 unsigned char checksum;
44 unsigned short length;
45 /* Terminating null required only for names < 12 chars. */
49 struct nvram_partition {
50 struct list_head partition;
51 struct nvram_header header;
55 static LIST_HEAD(nvram_partitions);
57 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
61 if (ppc_md.nvram_size == NULL)
63 size = ppc_md.nvram_size();
67 offset += file->f_pos;
80 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
81 size_t count, loff_t *ppos)
87 if (!ppc_md.nvram_size) {
92 size = ppc_md.nvram_size();
103 count = min_t(size_t, count, size - *ppos);
104 count = min(count, PAGE_SIZE);
106 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 nvram_partition * tmp_part;
210 printk(KERN_WARNING "--------%s---------\n", label);
211 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
212 list_for_each_entry(tmp_part, &nvram_partitions, partition) {
213 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12s\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 __init 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 __init 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;
249 * Per the criteria passed via nvram_remove_partition(), should this
250 * partition be removed? 1=remove, 0=keep
252 static int nvram_can_remove_partition(struct nvram_partition *part,
253 const char *name, int sig, const char *exceptions[])
255 if (part->header.signature != sig)
258 if (strncmp(name, part->header.name, 12))
260 } else if (exceptions) {
262 for (except = exceptions; *except; except++) {
263 if (!strncmp(*except, part->header.name, 12))
271 * nvram_remove_partition - Remove one or more partitions in nvram
272 * @name: name of the partition to remove, or NULL for a
273 * signature only match
274 * @sig: signature of the partition(s) to remove
275 * @exceptions: When removing all partitions with a matching signature,
279 int __init nvram_remove_partition(const char *name, int sig,
280 const char *exceptions[])
282 struct nvram_partition *part, *prev, *tmp;
285 list_for_each_entry(part, &nvram_partitions, partition) {
286 if (!nvram_can_remove_partition(part, name, sig, exceptions))
289 /* Make partition a free partition */
290 part->header.signature = NVRAM_SIG_FREE;
291 strncpy(part->header.name, "wwwwwwwwwwww", 12);
292 part->header.checksum = nvram_checksum(&part->header);
293 rc = nvram_write_header(part);
295 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
300 /* Merge contiguous ones */
302 list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
303 if (part->header.signature != NVRAM_SIG_FREE) {
308 prev->header.length += part->header.length;
309 prev->header.checksum = nvram_checksum(&part->header);
310 rc = nvram_write_header(part);
312 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
315 list_del(&part->partition);
325 * nvram_create_partition - Create a partition in nvram
326 * @name: name of the partition to create
327 * @sig: signature of the partition to create
328 * @req_size: size of data to allocate in bytes
329 * @min_size: minimum acceptable size (0 means req_size)
331 * Returns a negative error code or a positive nvram index
332 * of the beginning of the data area of the newly created
333 * partition. If you provided a min_size smaller than req_size
334 * you need to query for the actual size yourself after the
335 * call using nvram_partition_get_size().
337 loff_t __init nvram_create_partition(const char *name, int sig,
338 int req_size, int min_size)
340 struct nvram_partition *part;
341 struct nvram_partition *new_part;
342 struct nvram_partition *free_part = NULL;
343 static char nv_init_vals[16];
348 /* Convert sizes from bytes to blocks */
349 req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
350 min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
352 /* If no minimum size specified, make it the same as the
357 if (min_size > req_size)
360 /* Now add one block to each for the header */
364 /* Find a free partition that will give us the maximum needed size
365 If can't find one that will give us the minimum size needed */
366 list_for_each_entry(part, &nvram_partitions, partition) {
367 if (part->header.signature != NVRAM_SIG_FREE)
370 if (part->header.length >= req_size) {
375 if (part->header.length > size &&
376 part->header.length >= min_size) {
377 size = part->header.length;
384 /* Create our OS partition */
385 new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
387 pr_err("nvram_create_os_partition: kmalloc failed\n");
391 new_part->index = free_part->index;
392 new_part->header.signature = sig;
393 new_part->header.length = size;
394 strncpy(new_part->header.name, name, 12);
395 new_part->header.checksum = nvram_checksum(&new_part->header);
397 rc = nvram_write_header(new_part);
399 pr_err("nvram_create_os_partition: nvram_write_header "
400 "failed (%d)\n", rc);
403 list_add_tail(&new_part->partition, &free_part->partition);
405 /* Adjust or remove the partition we stole the space from */
406 if (free_part->header.length > size) {
407 free_part->index += size * NVRAM_BLOCK_LEN;
408 free_part->header.length -= size;
409 free_part->header.checksum = nvram_checksum(&free_part->header);
410 rc = nvram_write_header(free_part);
412 pr_err("nvram_create_os_partition: nvram_write_header "
413 "failed (%d)\n", rc);
417 list_del(&free_part->partition);
421 /* Clear the new partition */
422 for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
423 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
424 tmp_index += NVRAM_BLOCK_LEN) {
425 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
427 pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
432 return new_part->index + NVRAM_HEADER_LEN;
436 * nvram_get_partition_size - Get the data size of an nvram partition
437 * @data_index: This is the offset of the start of the data of
438 * the partition. The same value that is returned by
439 * nvram_create_partition().
441 int nvram_get_partition_size(loff_t data_index)
443 struct nvram_partition *part;
445 list_for_each_entry(part, &nvram_partitions, partition) {
446 if (part->index + NVRAM_HEADER_LEN == data_index)
447 return (part->header.length - 1) * NVRAM_BLOCK_LEN;
454 * nvram_find_partition - Find an nvram partition by signature and name
455 * @name: Name of the partition or NULL for any name
456 * @sig: Signature to test against
457 * @out_size: if non-NULL, returns the size of the data part of the partition
459 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
461 struct nvram_partition *p;
463 list_for_each_entry(p, &nvram_partitions, partition) {
464 if (p->header.signature == sig &&
465 (!name || !strncmp(p->header.name, name, 12))) {
467 *out_size = (p->header.length - 1) *
469 return p->index + NVRAM_HEADER_LEN;
475 int __init nvram_scan_partitions(void)
477 loff_t cur_index = 0;
478 struct nvram_header phead;
479 struct nvram_partition * tmp_part;
485 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
487 total_size = ppc_md.nvram_size();
489 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
491 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
495 while (cur_index < total_size) {
497 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
498 if (err != NVRAM_HEADER_LEN) {
499 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
500 "nvram partitions\n");
504 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
506 memcpy(&phead, header, NVRAM_HEADER_LEN);
509 c_sum = nvram_checksum(&phead);
510 if (c_sum != phead.checksum) {
511 printk(KERN_WARNING "WARNING: nvram partition checksum"
512 " was %02x, should be %02x!\n",
513 phead.checksum, c_sum);
514 printk(KERN_WARNING "Terminating nvram partition scan\n");
518 printk(KERN_WARNING "WARNING: nvram corruption "
519 "detected: 0-length partition\n");
522 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
525 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
529 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
530 tmp_part->index = cur_index;
531 list_add_tail(&tmp_part->partition, &nvram_partitions);
533 cur_index += phead.length * NVRAM_BLOCK_LEN;
538 nvram_print_partitions("NVRAM Partitions");
546 static int __init nvram_init(void)
550 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
552 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
555 rc = misc_register(&nvram_dev);
557 printk(KERN_ERR "nvram_init: failed to register device\n");
564 void __exit nvram_cleanup(void)
566 misc_deregister( &nvram_dev );
569 module_init(nvram_init);
570 module_exit(nvram_cleanup);
571 MODULE_LICENSE("GPL");