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)
88 if (!ppc_md.nvram_size)
92 size = ppc_md.nvram_size();
93 if (*ppos >= size || size < 0)
96 count = min_t(size_t, count, size - *ppos);
97 count = min(count, PAGE_SIZE);
100 tmp = kmalloc(count, GFP_KERNEL);
104 ret = ppc_md.nvram_read(tmp, count, ppos);
108 if (copy_to_user(buf, tmp, ret))
117 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
118 size_t count, loff_t *ppos)
125 if (!ppc_md.nvram_size)
129 size = ppc_md.nvram_size();
130 if (*ppos >= size || size < 0)
133 count = min_t(size_t, count, size - *ppos);
134 count = min(count, PAGE_SIZE);
137 tmp = kmalloc(count, GFP_KERNEL);
142 if (copy_from_user(tmp, buf, count))
145 ret = ppc_md.nvram_write(tmp, count, ppos);
153 static long dev_nvram_ioctl(struct file *file, unsigned int 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: {
163 if (!machine_is(powermac))
165 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
167 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
169 offset = pmac_get_partition(part);
172 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
176 #endif /* CONFIG_PPC_PMAC */
182 const 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 .unlocked_ioctl = dev_nvram_ioctl,
190 static struct miscdevice nvram_dev = {
198 static void __init nvram_print_partitions(char * label)
200 struct nvram_partition * tmp_part;
202 printk(KERN_WARNING "--------%s---------\n", label);
203 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
204 list_for_each_entry(tmp_part, &nvram_partitions, partition) {
205 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12s\n",
206 tmp_part->index, tmp_part->header.signature,
207 tmp_part->header.checksum, tmp_part->header.length,
208 tmp_part->header.name);
214 static int __init nvram_write_header(struct nvram_partition * part)
219 tmp_index = part->index;
220 rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
226 static unsigned char __init nvram_checksum(struct nvram_header *p)
228 unsigned int c_sum, c_sum2;
229 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
230 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
232 /* The sum may have spilled into the 3rd byte. Fold it back. */
233 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
234 /* The sum cannot exceed 2 bytes. Fold it into a checksum */
235 c_sum2 = (c_sum >> 8) + (c_sum << 8);
236 c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
241 * Per the criteria passed via nvram_remove_partition(), should this
242 * partition be removed? 1=remove, 0=keep
244 static int nvram_can_remove_partition(struct nvram_partition *part,
245 const char *name, int sig, const char *exceptions[])
247 if (part->header.signature != sig)
250 if (strncmp(name, part->header.name, 12))
252 } else if (exceptions) {
254 for (except = exceptions; *except; except++) {
255 if (!strncmp(*except, part->header.name, 12))
263 * nvram_remove_partition - Remove one or more partitions in nvram
264 * @name: name of the partition to remove, or NULL for a
265 * signature only match
266 * @sig: signature of the partition(s) to remove
267 * @exceptions: When removing all partitions with a matching signature,
271 int __init nvram_remove_partition(const char *name, int sig,
272 const char *exceptions[])
274 struct nvram_partition *part, *prev, *tmp;
277 list_for_each_entry(part, &nvram_partitions, partition) {
278 if (!nvram_can_remove_partition(part, name, sig, exceptions))
281 /* Make partition a free partition */
282 part->header.signature = NVRAM_SIG_FREE;
283 strncpy(part->header.name, "wwwwwwwwwwww", 12);
284 part->header.checksum = nvram_checksum(&part->header);
285 rc = nvram_write_header(part);
287 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
292 /* Merge contiguous ones */
294 list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
295 if (part->header.signature != NVRAM_SIG_FREE) {
300 prev->header.length += part->header.length;
301 prev->header.checksum = nvram_checksum(&part->header);
302 rc = nvram_write_header(part);
304 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
307 list_del(&part->partition);
317 * nvram_create_partition - Create a partition in nvram
318 * @name: name of the partition to create
319 * @sig: signature of the partition to create
320 * @req_size: size of data to allocate in bytes
321 * @min_size: minimum acceptable size (0 means req_size)
323 * Returns a negative error code or a positive nvram index
324 * of the beginning of the data area of the newly created
325 * partition. If you provided a min_size smaller than req_size
326 * you need to query for the actual size yourself after the
327 * call using nvram_partition_get_size().
329 loff_t __init nvram_create_partition(const char *name, int sig,
330 int req_size, int min_size)
332 struct nvram_partition *part;
333 struct nvram_partition *new_part;
334 struct nvram_partition *free_part = NULL;
335 static char nv_init_vals[16];
340 /* Convert sizes from bytes to blocks */
341 req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
342 min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
344 /* If no minimum size specified, make it the same as the
349 if (min_size > req_size)
352 /* Now add one block to each for the header */
356 /* Find a free partition that will give us the maximum needed size
357 If can't find one that will give us the minimum size needed */
358 list_for_each_entry(part, &nvram_partitions, partition) {
359 if (part->header.signature != NVRAM_SIG_FREE)
362 if (part->header.length >= req_size) {
367 if (part->header.length > size &&
368 part->header.length >= min_size) {
369 size = part->header.length;
376 /* Create our OS partition */
377 new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
379 pr_err("nvram_create_os_partition: kmalloc failed\n");
383 new_part->index = free_part->index;
384 new_part->header.signature = sig;
385 new_part->header.length = size;
386 strncpy(new_part->header.name, name, 12);
387 new_part->header.checksum = nvram_checksum(&new_part->header);
389 rc = nvram_write_header(new_part);
391 pr_err("nvram_create_os_partition: nvram_write_header "
392 "failed (%d)\n", rc);
395 list_add_tail(&new_part->partition, &free_part->partition);
397 /* Adjust or remove the partition we stole the space from */
398 if (free_part->header.length > size) {
399 free_part->index += size * NVRAM_BLOCK_LEN;
400 free_part->header.length -= size;
401 free_part->header.checksum = nvram_checksum(&free_part->header);
402 rc = nvram_write_header(free_part);
404 pr_err("nvram_create_os_partition: nvram_write_header "
405 "failed (%d)\n", rc);
409 list_del(&free_part->partition);
413 /* Clear the new partition */
414 for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
415 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
416 tmp_index += NVRAM_BLOCK_LEN) {
417 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
419 pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
424 return new_part->index + NVRAM_HEADER_LEN;
428 * nvram_get_partition_size - Get the data size of an nvram partition
429 * @data_index: This is the offset of the start of the data of
430 * the partition. The same value that is returned by
431 * nvram_create_partition().
433 int nvram_get_partition_size(loff_t data_index)
435 struct nvram_partition *part;
437 list_for_each_entry(part, &nvram_partitions, partition) {
438 if (part->index + NVRAM_HEADER_LEN == data_index)
439 return (part->header.length - 1) * NVRAM_BLOCK_LEN;
446 * nvram_find_partition - Find an nvram partition by signature and name
447 * @name: Name of the partition or NULL for any name
448 * @sig: Signature to test against
449 * @out_size: if non-NULL, returns the size of the data part of the partition
451 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
453 struct nvram_partition *p;
455 list_for_each_entry(p, &nvram_partitions, partition) {
456 if (p->header.signature == sig &&
457 (!name || !strncmp(p->header.name, name, 12))) {
459 *out_size = (p->header.length - 1) *
461 return p->index + NVRAM_HEADER_LEN;
467 int __init nvram_scan_partitions(void)
469 loff_t cur_index = 0;
470 struct nvram_header phead;
471 struct nvram_partition * tmp_part;
477 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
479 total_size = ppc_md.nvram_size();
481 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
483 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
487 while (cur_index < total_size) {
489 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
490 if (err != NVRAM_HEADER_LEN) {
491 printk(KERN_ERR "nvram_scan_partitions: Error parsing "
492 "nvram partitions\n");
496 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
498 memcpy(&phead, header, NVRAM_HEADER_LEN);
501 c_sum = nvram_checksum(&phead);
502 if (c_sum != phead.checksum) {
503 printk(KERN_WARNING "WARNING: nvram partition checksum"
504 " was %02x, should be %02x!\n",
505 phead.checksum, c_sum);
506 printk(KERN_WARNING "Terminating nvram partition scan\n");
510 printk(KERN_WARNING "WARNING: nvram corruption "
511 "detected: 0-length partition\n");
514 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
517 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
521 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
522 tmp_part->index = cur_index;
523 list_add_tail(&tmp_part->partition, &nvram_partitions);
525 cur_index += phead.length * NVRAM_BLOCK_LEN;
530 nvram_print_partitions("NVRAM Partitions");
538 static int __init nvram_init(void)
542 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
544 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
547 rc = misc_register(&nvram_dev);
549 printk(KERN_ERR "nvram_init: failed to register device\n");
556 void __exit nvram_cleanup(void)
558 misc_deregister( &nvram_dev );
561 module_init(nvram_init);
562 module_exit(nvram_cleanup);
563 MODULE_LICENSE("GPL");