[deliverable/linux.git] / arch / powerpc / kernel / nvram_64.c

/*
 *  c 2001 PPC 64 Team, IBM Corp
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 * /dev/nvram driver for PPC64
 *
 * This perhaps should live in drivers/char
 *
 * TODO: Split the /dev/nvram part (that one can use
 *       drivers/char/generic_nvram.c) from the arch & partition
 *       parsing code.
 */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/nvram.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/machdep.h>

#undef DEBUG_NVRAM

#define NVRAM_HEADER_LEN	sizeof(struct nvram_header)
#define NVRAM_BLOCK_LEN		NVRAM_HEADER_LEN

/* If change this size, then change the size of NVNAME_LEN */
struct nvram_header {
	unsigned char signature;
	unsigned char checksum;
	unsigned short length;
	/* Terminating null required only for names < 12 chars. */
	char name[12];
};

struct nvram_partition {
	struct list_head partition;
	struct nvram_header header;
	unsigned int index;
};

static LIST_HEAD(nvram_partitions);

static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
{
	int size;

	if (ppc_md.nvram_size == NULL)
		return -ENODEV;
	size = ppc_md.nvram_size();

	switch (origin) {
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += size;
		break;
	}
	if (offset < 0)
		return -EINVAL;
	file->f_pos = offset;
	return file->f_pos;
}


static ssize_t dev_nvram_read(struct file *file, char __user *buf,
			  size_t count, loff_t *ppos)
{
	ssize_t ret;
	char *tmp = NULL;
	ssize_t size;

	ret = -ENODEV;
	if (!ppc_md.nvram_size)
		goto out;

	ret = 0;
	size = ppc_md.nvram_size();
	if (*ppos >= size || size < 0)
		goto out;

	count = min_t(size_t, count, size - *ppos);
	count = min(count, PAGE_SIZE);

	ret = -ENOMEM;
	tmp = kmalloc(count, GFP_KERNEL);
	if (!tmp)
		goto out;

	ret = ppc_md.nvram_read(tmp, count, ppos);
	if (ret <= 0)
		goto out;

	if (copy_to_user(buf, tmp, ret))
		ret = -EFAULT;

out:
	kfree(tmp);
	return ret;

}

static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
			  size_t count, loff_t *ppos)
{
	ssize_t ret;
	char *tmp = NULL;
	ssize_t size;

	ret = -ENODEV;
	if (!ppc_md.nvram_size)
		goto out;

	ret = 0;
	size = ppc_md.nvram_size();
	if (*ppos >= size || size < 0)
		goto out;

	count = min_t(size_t, count, size - *ppos);
	count = min(count, PAGE_SIZE);

	ret = -ENOMEM;
	tmp = kmalloc(count, GFP_KERNEL);
	if (!tmp)
		goto out;

	ret = -EFAULT;
	if (copy_from_user(tmp, buf, count))
		goto out;

	ret = ppc_md.nvram_write(tmp, count, ppos);

out:
	kfree(tmp);
	return ret;

}

static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	switch(cmd) {
#ifdef CONFIG_PPC_PMAC
	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
		printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	case IOC_NVRAM_GET_OFFSET: {
		int part, offset;

		if (!machine_is(powermac))
			return -EINVAL;
		if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
			return -EFAULT;
		if (part < pmac_nvram_OF || part > pmac_nvram_NR)
			return -EINVAL;
		offset = pmac_get_partition(part);
		if (offset < 0)
			return offset;
		if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
			return -EFAULT;
		return 0;
	}
#endif /* CONFIG_PPC_PMAC */
	default:
		return -EINVAL;
	}
}

const struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= dev_nvram_llseek,
	.read		= dev_nvram_read,
	.write		= dev_nvram_write,
	.unlocked_ioctl	= dev_nvram_ioctl,
};

static struct miscdevice nvram_dev = {
	NVRAM_MINOR,
	"nvram",
	&nvram_fops
};


#ifdef DEBUG_NVRAM
static void __init nvram_print_partitions(char * label)
{
	struct nvram_partition * tmp_part;
	
	printk(KERN_WARNING "--------%s---------\n", label);
	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
	list_for_each_entry(tmp_part, &nvram_partitions, partition) {
		printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%12s\n",
		       tmp_part->index, tmp_part->header.signature,
		       tmp_part->header.checksum, tmp_part->header.length,
		       tmp_part->header.name);
	}
}
#endif


static int __init nvram_write_header(struct nvram_partition * part)
{
	loff_t tmp_index;
	int rc;
	
	tmp_index = part->index;
	rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index); 

	return rc;
}


static unsigned char __init nvram_checksum(struct nvram_header *p)
{
	unsigned int c_sum, c_sum2;
	unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
	c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];

	/* The sum may have spilled into the 3rd byte.  Fold it back. */
	c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
	/* The sum cannot exceed 2 bytes.  Fold it into a checksum */
	c_sum2 = (c_sum >> 8) + (c_sum << 8);
	c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
	return c_sum;
}

/**
 * nvram_remove_partition - Remove one or more partitions in nvram
 * @name: name of the partition to remove, or NULL for a
 *        signature only match
 * @sig: signature of the partition(s) to remove
 */

int __init nvram_remove_partition(const char *name, int sig)
{
	struct nvram_partition *part, *prev, *tmp;
	int rc;

	list_for_each_entry(part, &nvram_partitions, partition) {
		if (part->header.signature != sig)
			continue;
		if (name && strncmp(name, part->header.name, 12))
			continue;

		/* Make partition a free partition */
		part->header.signature = NVRAM_SIG_FREE;
		strncpy(part->header.name, "wwwwwwwwwwww", 12);
		part->header.checksum = nvram_checksum(&part->header);
		rc = nvram_write_header(part);
		if (rc <= 0) {
			printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
			return rc;
		}
	}

	/* Merge contiguous ones */
	prev = NULL;
	list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
		if (part->header.signature != NVRAM_SIG_FREE) {
			prev = NULL;
			continue;
		}
		if (prev) {
			prev->header.length += part->header.length;
			prev->header.checksum = nvram_checksum(&part->header);
			rc = nvram_write_header(part);
			if (rc <= 0) {
				printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
				return rc;
			}
			list_del(&part->partition);
			kfree(part);
		} else
			prev = part;
	}
	
	return 0;
}

/**
 * nvram_create_partition - Create a partition in nvram
 * @name: name of the partition to create
 * @sig: signature of the partition to create
 * @req_size: size of data to allocate in bytes
 * @min_size: minimum acceptable size (0 means req_size)
 *
 * Returns a negative error code or a positive nvram index
 * of the beginning of the data area of the newly created
 * partition. If you provided a min_size smaller than req_size
 * you need to query for the actual size yourself after the
 * call using nvram_partition_get_size().
 */
loff_t __init nvram_create_partition(const char *name, int sig,
				     int req_size, int min_size)
{
	struct nvram_partition *part;
	struct nvram_partition *new_part;
	struct nvram_partition *free_part = NULL;
	static char nv_init_vals[16];
	loff_t tmp_index;
	long size = 0;
	int rc;

	/* Convert sizes from bytes to blocks */
	req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;

	/* If no minimum size specified, make it the same as the
	 * requested size
	 */
	if (min_size == 0)
		min_size = req_size;
	if (min_size > req_size)
		return -EINVAL;

	/* Now add one block to each for the header */
	req_size += 1;
	min_size += 1;

	/* Find a free partition that will give us the maximum needed size 
	   If can't find one that will give us the minimum size needed */
	list_for_each_entry(part, &nvram_partitions, partition) {
		if (part->header.signature != NVRAM_SIG_FREE)
			continue;

		if (part->header.length >= req_size) {
			size = req_size;
			free_part = part;
			break;
		}
		if (part->header.length > size &&
		    part->header.length >= min_size) {
			size = part->header.length;
			free_part = part;
		}
	}
	if (!size)
		return -ENOSPC;
	
	/* Create our OS partition */
	new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
	if (!new_part) {
		pr_err("nvram_create_os_partition: kmalloc failed\n");
		return -ENOMEM;
	}

	new_part->index = free_part->index;
	new_part->header.signature = sig;
	new_part->header.length = size;
	strncpy(new_part->header.name, name, 12);
	new_part->header.checksum = nvram_checksum(&new_part->header);

	rc = nvram_write_header(new_part);
	if (rc <= 0) {
		pr_err("nvram_create_os_partition: nvram_write_header "
		       "failed (%d)\n", rc);
		return rc;
	}
	list_add_tail(&new_part->partition, &free_part->partition);

	/* Adjust or remove the partition we stole the space from */
	if (free_part->header.length > size) {
		free_part->index += size * NVRAM_BLOCK_LEN;
		free_part->header.length -= size;
		free_part->header.checksum = nvram_checksum(&free_part->header);
		rc = nvram_write_header(free_part);
		if (rc <= 0) {
			pr_err("nvram_create_os_partition: nvram_write_header "
			       "failed (%d)\n", rc);
			return rc;
		}
	} else {
		list_del(&free_part->partition);
		kfree(free_part);
	} 

	/* Clear the new partition */
	for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
	     tmp_index <  ((size - 1) * NVRAM_BLOCK_LEN);
	     tmp_index += NVRAM_BLOCK_LEN) {
		rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
		if (rc <= 0) {
			pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
			return rc;
		}
	}
	
	return new_part->index + NVRAM_HEADER_LEN;
}

/**
 * nvram_get_partition_size - Get the data size of an nvram partition
 * @data_index: This is the offset of the start of the data of
 *              the partition. The same value that is returned by
 *              nvram_create_partition().
 */
int nvram_get_partition_size(loff_t data_index)
{
	struct nvram_partition *part;
	
	list_for_each_entry(part, &nvram_partitions, partition) {
		if (part->index + NVRAM_HEADER_LEN == data_index)
			return (part->header.length - 1) * NVRAM_BLOCK_LEN;
	}
	return -1;
}


/**
 * nvram_find_partition - Find an nvram partition by signature and name
 * @name: Name of the partition or NULL for any name
 * @sig: Signature to test against
 * @out_size: if non-NULL, returns the size of the data part of the partition
 */
loff_t nvram_find_partition(const char *name, int sig, int *out_size)
{
	struct nvram_partition *p;

	list_for_each_entry(p, &nvram_partitions, partition) {
		if (p->header.signature == sig &&
		    (!name || !strncmp(p->header.name, name, 12))) {
			if (out_size)
				*out_size = (p->header.length - 1) *
					NVRAM_BLOCK_LEN;
			return p->index + NVRAM_HEADER_LEN;
		}
	}
	return 0;
}

int __init nvram_scan_partitions(void)
{
	loff_t cur_index = 0;
	struct nvram_header phead;
	struct nvram_partition * tmp_part;
	unsigned char c_sum;
	char * header;
	int total_size;
	int err;

	if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
		return -ENODEV;
	total_size = ppc_md.nvram_size();
	
	header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
	if (!header) {
		printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
		return -ENOMEM;
	}

	while (cur_index < total_size) {

		err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
		if (err != NVRAM_HEADER_LEN) {
			printk(KERN_ERR "nvram_scan_partitions: Error parsing "
			       "nvram partitions\n");
			goto out;
		}

		cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */

		memcpy(&phead, header, NVRAM_HEADER_LEN);

		err = 0;
		c_sum = nvram_checksum(&phead);
		if (c_sum != phead.checksum) {
			printk(KERN_WARNING "WARNING: nvram partition checksum"
			       " was %02x, should be %02x!\n",
			       phead.checksum, c_sum);
			printk(KERN_WARNING "Terminating nvram partition scan\n");
			goto out;
		}
		if (!phead.length) {
			printk(KERN_WARNING "WARNING: nvram corruption "
			       "detected: 0-length partition\n");
			goto out;
		}
		tmp_part = (struct nvram_partition *)
			kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
		err = -ENOMEM;
		if (!tmp_part) {
			printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
			goto out;
		}
		
		memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
		tmp_part->index = cur_index;
		list_add_tail(&tmp_part->partition, &nvram_partitions);
		
		cur_index += phead.length * NVRAM_BLOCK_LEN;
	}
	err = 0;

#ifdef DEBUG_NVRAM
	nvram_print_partitions("NVRAM Partitions");
#endif

 out:
	kfree(header);
	return err;
}

static int __init nvram_init(void)
{
	int rc;
	
	BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);

	if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
		return  -ENODEV;

  	rc = misc_register(&nvram_dev);
	if (rc != 0) {
		printk(KERN_ERR "nvram_init: failed to register device\n");
		return rc;
	}
  	
  	return rc;
}

void __exit nvram_cleanup(void)
{
        misc_deregister( &nvram_dev );
}

module_init(nvram_init);
module_exit(nvram_cleanup);
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* c 2001 PPC 64 Team, IBM Corp
	3	*
	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.
	8	*
	9	* /dev/nvram driver for PPC64
	10	*
	11	* This perhaps should live in drivers/char
	12	*
	13	* TODO: Split the /dev/nvram part (that one can use
	14	* drivers/char/generic_nvram.c) from the arch & partition
	15	* parsing code.
	16	*/
	17
	18	#include <linux/module.h>
	19
	20	#include <linux/types.h>
	21	#include <linux/errno.h>
	22	#include <linux/fs.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>
	31	#include <asm/rtas.h>
	32	#include <asm/prom.h>
	33	#include <asm/machdep.h>
1da177e4 LT	34
	35	#undef DEBUG_NVRAM
	36
36673307 BH	37	#define NVRAM_HEADER_LEN sizeof(struct nvram_header)
36673307 BH	38	#define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
74d51d02 BH	39
	40	/* If change this size, then change the size of NVNAME_LEN */
	41	struct nvram_header {
	42	unsigned char signature;
	43	unsigned char checksum;
	44	unsigned short length;
6024ede9	45	/* Terminating null required only for names < 12 chars. */
74d51d02 BH	46	char name[12];
	47	};
	48
	49	struct nvram_partition {
	50	struct list_head partition;
	51	struct nvram_header header;
	52	unsigned int index;
	53	};
	54
690d1a9b	55	static LIST_HEAD(nvram_partitions);
1da177e4 LT	56
	57	static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
	58	{
	59	int size;
	60
	61	if (ppc_md.nvram_size == NULL)
	62	return -ENODEV;
	63	size = ppc_md.nvram_size();
	64
	65	switch (origin) {
	66	case 1:
	67	offset += file->f_pos;
	68	break;
	69	case 2:
	70	offset += size;
	71	break;
	72	}
	73	if (offset < 0)
	74	return -EINVAL;
	75	file->f_pos = offset;
	76	return file->f_pos;
	77	}
	78
	79
	80	static ssize_t dev_nvram_read(struct file file, char __user buf,
	81	size_t count, loff_t *ppos)
	82	{
f9ce299f AB	83	ssize_t ret;
	84	char *tmp = NULL;
	85	ssize_t size;
1da177e4	86
f9ce299f AB	87	ret = -ENODEV;
	88	if (!ppc_md.nvram_size)
	89	goto out;
	90
	91	ret = 0;
1da177e4	92	size = ppc_md.nvram_size();
f9ce299f AB	93	if (*ppos >= size \|\| size < 0)
f9ce299f AB	94	goto out;
1da177e4	95
f9ce299f AB	96	count = min_t(size_t, count, size - *ppos);
f9ce299f AB	97	count = min(count, PAGE_SIZE);
1da177e4	98
f9ce299f AB	99	ret = -ENOMEM;
	100	tmp = kmalloc(count, GFP_KERNEL);
	101	if (!tmp)
	102	goto out;
1da177e4	103
f9ce299f AB	104	ret = ppc_md.nvram_read(tmp, count, ppos);
	105	if (ret <= 0)
	106	goto out;
	107
	108	if (copy_to_user(buf, tmp, ret))
	109	ret = -EFAULT;
1da177e4	110
f9ce299f AB	111	out:
	112	kfree(tmp);
	113	return ret;
1da177e4 LT	114
	115	}
	116
	117	static ssize_t dev_nvram_write(struct file file, const char __user buf,
f9ce299f	118	size_t count, loff_t *ppos)
1da177e4	119	{
f9ce299f AB	120	ssize_t ret;
	121	char *tmp = NULL;
	122	ssize_t size;
1da177e4	123
f9ce299f AB	124	ret = -ENODEV;
	125	if (!ppc_md.nvram_size)
	126	goto out;
	127
	128	ret = 0;
1da177e4	129	size = ppc_md.nvram_size();
f9ce299f AB	130	if (*ppos >= size \|\| size < 0)
f9ce299f AB	131	goto out;
1da177e4	132
f9ce299f AB	133	count = min_t(size_t, count, size - *ppos);
f9ce299f AB	134	count = min(count, PAGE_SIZE);
1da177e4	135
f9ce299f AB	136	ret = -ENOMEM;
	137	tmp = kmalloc(count, GFP_KERNEL);
	138	if (!tmp)
	139	goto out;
	140
	141	ret = -EFAULT;
	142	if (copy_from_user(tmp, buf, count))
	143	goto out;
	144
	145	ret = ppc_md.nvram_write(tmp, count, ppos);
	146
	147	out:
	148	kfree(tmp);
	149	return ret;
1da177e4	150
1da177e4 LT	151	}
1da177e4 LT	152
3b03fecd TG	153	static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
3b03fecd TG	154	unsigned long arg)
1da177e4 LT	155	{
	156	switch(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: {
	161	int part, offset;
	162
e8222502	163	if (!machine_is(powermac))
1da177e4 LT	164	return -EINVAL;
	165	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	166	return -EFAULT;
	167	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	168	return -EINVAL;
	169	offset = pmac_get_partition(part);
	170	if (offset < 0)
	171	return offset;
	172	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	173	return -EFAULT;
	174	return 0;
	175	}
	176	#endif /* CONFIG_PPC_PMAC */
af308377 SR	177	default:
af308377 SR	178	return -EINVAL;
1da177e4	179	}
1da177e4 LT	180	}
1da177e4 LT	181
5dfe4c96	182	const struct file_operations nvram_fops = {
3b03fecd TG	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,
1da177e4 LT	188	};
	189
	190	static struct miscdevice nvram_dev = {
	191	NVRAM_MINOR,
	192	"nvram",
	193	&nvram_fops
	194	};
	195
	196
	197	#ifdef DEBUG_NVRAM
32c105c3	198	static void __init nvram_print_partitions(char * label)
1da177e4	199	{
1da177e4 LT	200	struct nvram_partition * tmp_part;
	201
	202	printk(KERN_WARNING "--------%s---------\n", label);
	203	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
690d1a9b	204	list_for_each_entry(tmp_part, &nvram_partitions, partition) {
6024ede9	205	printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12s\n",
1da177e4 LT	206	tmp_part->index, tmp_part->header.signature,
	207	tmp_part->header.checksum, tmp_part->header.length,
	208	tmp_part->header.name);
	209	}
	210	}
	211	#endif
	212
	213
32c105c3	214	static int __init nvram_write_header(struct nvram_partition * part)
1da177e4 LT	215	{
	216	loff_t tmp_index;
	217	int rc;
	218
	219	tmp_index = part->index;
	220	rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
	221
	222	return rc;
	223	}
	224
	225
32c105c3	226	static unsigned char __init nvram_checksum(struct nvram_header *p)
1da177e4 LT	227	{
	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];
	231
	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;
	237	return c_sum;
	238	}
	239
fa2b4e54 BH	240	/**
	241	* nvram_remove_partition - Remove one or more partitions in nvram
	242	* @name: name of the partition to remove, or NULL for a
	243	* signature only match
	244	* @sig: signature of the partition(s) to remove
	245	*/
	246
edc79a2f	247	int __init nvram_remove_partition(const char *name, int sig)
1da177e4	248	{
fa2b4e54	249	struct nvram_partition part, prev, *tmp;
1da177e4 LT	250	int rc;
1da177e4 LT	251
690d1a9b	252	list_for_each_entry(part, &nvram_partitions, partition) {
fa2b4e54	253	if (part->header.signature != sig)
1da177e4	254	continue;
fa2b4e54 BH	255	if (name && strncmp(name, part->header.name, 12))
	256	continue;
	257
	258	/* Make partition a free partition */
1da177e4	259	part->header.signature = NVRAM_SIG_FREE;
6024ede9	260	strncpy(part->header.name, "wwwwwwwwwwww", 12);
1da177e4	261	part->header.checksum = nvram_checksum(&part->header);
1da177e4 LT	262	rc = nvram_write_header(part);
1da177e4 LT	263	if (rc <= 0) {
fa2b4e54	264	printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
1da177e4 LT	265	return rc;
1da177e4 LT	266	}
fa2b4e54	267	}
1da177e4	268
fa2b4e54 BH	269	/* Merge contiguous ones */
fa2b4e54 BH	270	prev = NULL;
690d1a9b	271	list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
fa2b4e54 BH	272	if (part->header.signature != NVRAM_SIG_FREE) {
	273	prev = NULL;
	274	continue;
	275	}
	276	if (prev) {
	277	prev->header.length += part->header.length;
	278	prev->header.checksum = nvram_checksum(&part->header);
	279	rc = nvram_write_header(part);
	280	if (rc <= 0) {
	281	printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
	282	return rc;
	283	}
	284	list_del(&part->partition);
	285	kfree(part);
	286	} else
	287	prev = part;
1da177e4 LT	288	}
	289
	290	return 0;
	291	}
	292
4e7c77a3 BH	293	/**
	294	* nvram_create_partition - Create a partition in nvram
	295	* @name: name of the partition to create
	296	* @sig: signature of the partition to create
36673307	297	* @req_size: size of data to allocate in bytes
4e7c77a3	298	* @min_size: minimum acceptable size (0 means req_size)
e49e2e87 BH	299	*
	300	* Returns a negative error code or a positive nvram index
	301	* of the beginning of the data area of the newly created
	302	* partition. If you provided a min_size smaller than req_size
	303	* you need to query for the actual size yourself after the
	304	* call using nvram_partition_get_size().
1da177e4	305	*/
edc79a2f BH	306	loff_t __init nvram_create_partition(const char *name, int sig,
edc79a2f BH	307	int req_size, int min_size)
1da177e4	308	{
a341ad97 AB	309	struct nvram_partition *part;
a341ad97 AB	310	struct nvram_partition *new_part;
0339ad77	311	struct nvram_partition *free_part = NULL;
cef0d5ad	312	static char nv_init_vals[16];
1da177e4 LT	313	loff_t tmp_index;
	314	long size = 0;
	315	int rc;
4e7c77a3	316
36673307 BH	317	/* Convert sizes from bytes to blocks */
	318	req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	319	min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	320
4e7c77a3 BH	321	/* If no minimum size specified, make it the same as the
	322	* requested size
	323	*/
	324	if (min_size == 0)
	325	min_size = req_size;
e49e2e87 BH	326	if (min_size > req_size)
e49e2e87 BH	327	return -EINVAL;
4e7c77a3	328
36673307 BH	329	/* Now add one block to each for the header */
	330	req_size += 1;
	331	min_size += 1;
	332
1da177e4 LT	333	/* Find a free partition that will give us the maximum needed size
1da177e4 LT	334	If can't find one that will give us the minimum size needed */
690d1a9b	335	list_for_each_entry(part, &nvram_partitions, partition) {
1da177e4 LT	336	if (part->header.signature != NVRAM_SIG_FREE)
	337	continue;
	338
4e7c77a3 BH	339	if (part->header.length >= req_size) {
4e7c77a3 BH	340	size = req_size;
1da177e4 LT	341	free_part = part;
	342	break;
	343	}
4e7c77a3 BH	344	if (part->header.length > size &&
	345	part->header.length >= min_size) {
	346	size = part->header.length;
1da177e4 LT	347	free_part = part;
	348	}
	349	}
0339ad77	350	if (!size)
1da177e4	351	return -ENOSPC;
1da177e4 LT	352
1da177e4 LT	353	/* Create our OS partition */
0339ad77	354	new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1da177e4	355	if (!new_part) {
e49e2e87	356	pr_err("nvram_create_os_partition: kmalloc failed\n");
1da177e4 LT	357	return -ENOMEM;
	358	}
	359
	360	new_part->index = free_part->index;
4e7c77a3	361	new_part->header.signature = sig;
1da177e4	362	new_part->header.length = size;
4e7c77a3	363	strncpy(new_part->header.name, name, 12);
1da177e4 LT	364	new_part->header.checksum = nvram_checksum(&new_part->header);
	365
	366	rc = nvram_write_header(new_part);
	367	if (rc <= 0) {
e49e2e87 BH	368	pr_err("nvram_create_os_partition: nvram_write_header "
e49e2e87 BH	369	"failed (%d)\n", rc);
1da177e4 LT	370	return rc;
1da177e4 LT	371	}
e49e2e87 BH	372	list_add_tail(&new_part->partition, &free_part->partition);
	373
	374	/* Adjust or remove the partition we stole the space from */
	375	if (free_part->header.length > size) {
	376	free_part->index += size * NVRAM_BLOCK_LEN;
	377	free_part->header.length -= size;
	378	free_part->header.checksum = nvram_checksum(&free_part->header);
	379	rc = nvram_write_header(free_part);
	380	if (rc <= 0) {
	381	pr_err("nvram_create_os_partition: nvram_write_header "
	382	"failed (%d)\n", rc);
	383	return rc;
	384	}
	385	} else {
	386	list_del(&free_part->partition);
	387	kfree(free_part);
	388	}
1da177e4	389
e49e2e87	390	/* Clear the new partition */
cef0d5ad BH	391	for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
	392	tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
	393	tmp_index += NVRAM_BLOCK_LEN) {
	394	rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
	395	if (rc <= 0) {
	396	pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
	397	return rc;
	398	}
1da177e4 LT	399	}
1da177e4 LT	400
e49e2e87 BH	401	return new_part->index + NVRAM_HEADER_LEN;
e49e2e87 BH	402	}
1da177e4	403
e49e2e87 BH	404	/**
	405	* nvram_get_partition_size - Get the data size of an nvram partition
	406	* @data_index: This is the offset of the start of the data of
	407	* the partition. The same value that is returned by
	408	* nvram_create_partition().
	409	*/
edc79a2f	410	int nvram_get_partition_size(loff_t data_index)
e49e2e87 BH	411	{
e49e2e87 BH	412	struct nvram_partition *part;
1da177e4	413
690d1a9b	414	list_for_each_entry(part, &nvram_partitions, partition) {
e49e2e87 BH	415	if (part->index + NVRAM_HEADER_LEN == data_index)
e49e2e87 BH	416	return (part->header.length - 1) * NVRAM_BLOCK_LEN;
1da177e4	417	}
e49e2e87	418	return -1;
1da177e4 LT	419	}
	420
	421
cf5cbf9f BH	422	/**
	423	* nvram_find_partition - Find an nvram partition by signature and name
	424	* @name: Name of the partition or NULL for any name
	425	* @sig: Signature to test against
	426	* @out_size: if non-NULL, returns the size of the data part of the partition
	427	*/
	428	loff_t nvram_find_partition(const char name, int sig, int out_size)
	429	{
	430	struct nvram_partition *p;
	431
690d1a9b	432	list_for_each_entry(p, &nvram_partitions, partition) {
cf5cbf9f BH	433	if (p->header.signature == sig &&
	434	(!name \|\| !strncmp(p->header.name, name, 12))) {
	435	if (out_size)
	436	out_size = (p->header.length - 1)
	437	NVRAM_BLOCK_LEN;
	438	return p->index + NVRAM_HEADER_LEN;
	439	}
	440	}
	441	return 0;
	442	}
	443
edc79a2f	444	int __init nvram_scan_partitions(void)
1da177e4 LT	445	{
	446	loff_t cur_index = 0;
	447	struct nvram_header phead;
	448	struct nvram_partition * tmp_part;
	449	unsigned char c_sum;
	450	char * header;
	451	int total_size;
	452	int err;
	453
edc79a2f	454	if (ppc_md.nvram_size == NULL \|\| ppc_md.nvram_size() <= 0)
1da177e4 LT	455	return -ENODEV;
	456	total_size = ppc_md.nvram_size();
	457
5cbded58	458	header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1da177e4 LT	459	if (!header) {
	460	printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
	461	return -ENOMEM;
	462	}
	463
	464	while (cur_index < total_size) {
	465
	466	err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
	467	if (err != NVRAM_HEADER_LEN) {
	468	printk(KERN_ERR "nvram_scan_partitions: Error parsing "
	469	"nvram partitions\n");
	470	goto out;
	471	}
	472
	473	cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
	474
	475	memcpy(&phead, header, NVRAM_HEADER_LEN);
	476
	477	err = 0;
	478	c_sum = nvram_checksum(&phead);
	479	if (c_sum != phead.checksum) {
	480	printk(KERN_WARNING "WARNING: nvram partition checksum"
	481	" was %02x, should be %02x!\n",
	482	phead.checksum, c_sum);
	483	printk(KERN_WARNING "Terminating nvram partition scan\n");
	484	goto out;
	485	}
	486	if (!phead.length) {
	487	printk(KERN_WARNING "WARNING: nvram corruption "
	488	"detected: 0-length partition\n");
	489	goto out;
	490	}
	491	tmp_part = (struct nvram_partition *)
	492	kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
	493	err = -ENOMEM;
	494	if (!tmp_part) {
	495	printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
	496	goto out;
	497	}
	498
	499	memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
	500	tmp_part->index = cur_index;
690d1a9b	501	list_add_tail(&tmp_part->partition, &nvram_partitions);
1da177e4 LT	502
	503	cur_index += phead.length * NVRAM_BLOCK_LEN;
	504	}
	505	err = 0;
	506
edc79a2f BH	507	#ifdef DEBUG_NVRAM
	508	nvram_print_partitions("NVRAM Partitions");
	509	#endif
	510
1da177e4 LT	511	out:
	512	kfree(header);
	513	return err;
	514	}
	515
	516	static int __init nvram_init(void)
	517	{
1da177e4 LT	518	int rc;
1da177e4 LT	519
578914cf BH	520	BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
578914cf BH	521
1da177e4 LT	522	if (ppc_md.nvram_size == NULL \|\| ppc_md.nvram_size() <= 0)
	523	return -ENODEV;
	524
	525	rc = misc_register(&nvram_dev);
	526	if (rc != 0) {
	527	printk(KERN_ERR "nvram_init: failed to register device\n");
	528	return rc;
	529	}
	530
1da177e4 LT	531	return rc;
	532	}
	533
	534	void __exit nvram_cleanup(void)
	535	{
	536	misc_deregister( &nvram_dev );
	537	}
	538
1da177e4 LT	539	module_init(nvram_init);
	540	module_exit(nvram_cleanup);
	541	MODULE_LICENSE("GPL");