[mirror_ubuntu-artful-kernel.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;

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

	size = ppc_md.nvram_size();
	if (size < 0) {
		ret = size;
		goto out;
	}

	if (*ppos >= size) {
		ret = 0;
		goto out;
	}

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

	tmp = kmalloc(count, GFP_KERNEL);
	if (!tmp) {
		ret = -ENOMEM;
		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%12.12s\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;
	struct nvram_header phead;

	memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
	phead.length = cpu_to_be16(phead.length);

	tmp_index = part->index;
	rc = ppc_md.nvram_write((char *)&phead, 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;
}

/*
 * Per the criteria passed via nvram_remove_partition(), should this
 * partition be removed?  1=remove, 0=keep
 */
static int nvram_can_remove_partition(struct nvram_partition *part,
		const char *name, int sig, const char *exceptions[])
{
	if (part->header.signature != sig)
		return 0;
	if (name) {
		if (strncmp(name, part->header.name, 12))
			return 0;
	} else if (exceptions) {
		const char **except;
		for (except = exceptions; *except; except++) {
			if (!strncmp(*except, part->header.name, 12))
				return 0;
		}
	}
	return 1;
}

/**
 * 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
 * @exceptions: When removing all partitions with a matching signature,
 *        leave these alone.
 */

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

	list_for_each_entry(part, &nvram_partitions, partition) {
		if (!nvram_can_remove_partition(part, name, sig, exceptions))
			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);

		phead.length = be16_to_cpu(phead.length);

		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 = 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;
}

static 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
7029705a CG	87	if (!ppc_md.nvram_size) {
7029705a CG	88	ret = -ENODEV;
f9ce299f	89	goto out;
7029705a	90	}
f9ce299f	91
1da177e4	92	size = ppc_md.nvram_size();
7029705a CG	93	if (size < 0) {
7029705a CG	94	ret = size;
f9ce299f	95	goto out;
7029705a CG	96	}
	97
	98	if (*ppos >= size) {
	99	ret = 0;
	100	goto out;
	101	}
1da177e4	102
f9ce299f AB	103	count = min_t(size_t, count, size - *ppos);
f9ce299f AB	104	count = min(count, PAGE_SIZE);
1da177e4	105
f9ce299f	106	tmp = kmalloc(count, GFP_KERNEL);
7029705a CG	107	if (!tmp) {
7029705a CG	108	ret = -ENOMEM;
f9ce299f	109	goto out;
7029705a	110	}
1da177e4	111
f9ce299f AB	112	ret = ppc_md.nvram_read(tmp, count, ppos);
	113	if (ret <= 0)
	114	goto out;
	115
	116	if (copy_to_user(buf, tmp, ret))
	117	ret = -EFAULT;
1da177e4	118
f9ce299f AB	119	out:
	120	kfree(tmp);
	121	return ret;
1da177e4 LT	122
	123	}
	124
	125	static ssize_t dev_nvram_write(struct file file, const char __user buf,
f9ce299f	126	size_t count, loff_t *ppos)
1da177e4	127	{
f9ce299f AB	128	ssize_t ret;
	129	char *tmp = NULL;
	130	ssize_t size;
1da177e4	131
f9ce299f AB	132	ret = -ENODEV;
	133	if (!ppc_md.nvram_size)
	134	goto out;
	135
	136	ret = 0;
1da177e4	137	size = ppc_md.nvram_size();
f9ce299f AB	138	if (*ppos >= size \|\| size < 0)
f9ce299f AB	139	goto out;
1da177e4	140
f9ce299f AB	141	count = min_t(size_t, count, size - *ppos);
f9ce299f AB	142	count = min(count, PAGE_SIZE);
1da177e4	143
f9ce299f AB	144	ret = -ENOMEM;
	145	tmp = kmalloc(count, GFP_KERNEL);
	146	if (!tmp)
	147	goto out;
	148
	149	ret = -EFAULT;
	150	if (copy_from_user(tmp, buf, count))
	151	goto out;
	152
	153	ret = ppc_md.nvram_write(tmp, count, ppos);
	154
	155	out:
	156	kfree(tmp);
	157	return ret;
1da177e4	158
1da177e4 LT	159	}
1da177e4 LT	160
3b03fecd TG	161	static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
3b03fecd TG	162	unsigned long arg)
1da177e4 LT	163	{
	164	switch(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: {
	169	int part, offset;
	170
e8222502	171	if (!machine_is(powermac))
1da177e4 LT	172	return -EINVAL;
	173	if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
	174	return -EFAULT;
	175	if (part < pmac_nvram_OF \|\| part > pmac_nvram_NR)
	176	return -EINVAL;
	177	offset = pmac_get_partition(part);
	178	if (offset < 0)
	179	return offset;
	180	if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
	181	return -EFAULT;
	182	return 0;
	183	}
	184	#endif /* CONFIG_PPC_PMAC */
af308377 SR	185	default:
af308377 SR	186	return -EINVAL;
1da177e4	187	}
1da177e4 LT	188	}
1da177e4 LT	189
5dfe4c96	190	const struct file_operations nvram_fops = {
3b03fecd TG	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,
1da177e4 LT	196	};
	197
	198	static struct miscdevice nvram_dev = {
	199	NVRAM_MINOR,
	200	"nvram",
	201	&nvram_fops
	202	};
	203
	204
	205	#ifdef DEBUG_NVRAM
32c105c3	206	static void __init nvram_print_partitions(char * label)
1da177e4	207	{
1da177e4 LT	208	struct nvram_partition * tmp_part;
	209
	210	printk(KERN_WARNING "--------%s---------\n", label);
	211	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
690d1a9b	212	list_for_each_entry(tmp_part, &nvram_partitions, partition) {
e0513d9e	213	printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12.12s\n",
1da177e4 LT	214	tmp_part->index, tmp_part->header.signature,
	215	tmp_part->header.checksum, tmp_part->header.length,
	216	tmp_part->header.name);
	217	}
	218	}
	219	#endif
	220
	221
32c105c3	222	static int __init nvram_write_header(struct nvram_partition * part)
1da177e4 LT	223	{
	224	loff_t tmp_index;
	225	int rc;
c81095a4 CLG	226	struct nvram_header phead;
	227
	228	memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
	229	phead.length = cpu_to_be16(phead.length);
	230
1da177e4	231	tmp_index = part->index;
c81095a4	232	rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
1da177e4 LT	233
	234	return rc;
	235	}
	236
	237
32c105c3	238	static unsigned char __init nvram_checksum(struct nvram_header *p)
1da177e4 LT	239	{
	240	unsigned int c_sum, c_sum2;
	241	unsigned short sp = (unsigned short )p->name; /* assume 6 shorts */
	242	c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
	243
	244	/* The sum may have spilled into the 3rd byte. Fold it back. */
	245	c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
	246	/* The sum cannot exceed 2 bytes. Fold it into a checksum */
	247	c_sum2 = (c_sum >> 8) + (c_sum << 8);
	248	c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
	249	return c_sum;
	250	}
	251
0f4ac132 JK	252	/*
	253	* Per the criteria passed via nvram_remove_partition(), should this
	254	* partition be removed? 1=remove, 0=keep
	255	*/
	256	static int nvram_can_remove_partition(struct nvram_partition *part,
	257	const char name, int sig, const char exceptions[])
	258	{
	259	if (part->header.signature != sig)
	260	return 0;
	261	if (name) {
	262	if (strncmp(name, part->header.name, 12))
	263	return 0;
	264	} else if (exceptions) {
	265	const char **except;
	266	for (except = exceptions; *except; except++) {
	267	if (!strncmp(*except, part->header.name, 12))
	268	return 0;
	269	}
	270	}
	271	return 1;
	272	}
	273
fa2b4e54 BH	274	/**
	275	* nvram_remove_partition - Remove one or more partitions in nvram
	276	* @name: name of the partition to remove, or NULL for a
	277	* signature only match
	278	* @sig: signature of the partition(s) to remove
0f4ac132 JK	279	* @exceptions: When removing all partitions with a matching signature,
0f4ac132 JK	280	* leave these alone.
fa2b4e54 BH	281	*/
fa2b4e54 BH	282
0f4ac132 JK	283	int __init nvram_remove_partition(const char *name, int sig,
0f4ac132 JK	284	const char *exceptions[])
1da177e4	285	{
fa2b4e54	286	struct nvram_partition part, prev, *tmp;
1da177e4 LT	287	int rc;
1da177e4 LT	288
690d1a9b	289	list_for_each_entry(part, &nvram_partitions, partition) {
0f4ac132	290	if (!nvram_can_remove_partition(part, name, sig, exceptions))
fa2b4e54 BH	291	continue;
	292
	293	/* Make partition a free partition */
1da177e4	294	part->header.signature = NVRAM_SIG_FREE;
6024ede9	295	strncpy(part->header.name, "wwwwwwwwwwww", 12);
1da177e4	296	part->header.checksum = nvram_checksum(&part->header);
1da177e4 LT	297	rc = nvram_write_header(part);
1da177e4 LT	298	if (rc <= 0) {
fa2b4e54	299	printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
1da177e4 LT	300	return rc;
1da177e4 LT	301	}
fa2b4e54	302	}
1da177e4	303
fa2b4e54 BH	304	/* Merge contiguous ones */
fa2b4e54 BH	305	prev = NULL;
690d1a9b	306	list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
fa2b4e54 BH	307	if (part->header.signature != NVRAM_SIG_FREE) {
	308	prev = NULL;
	309	continue;
	310	}
	311	if (prev) {
	312	prev->header.length += part->header.length;
	313	prev->header.checksum = nvram_checksum(&part->header);
	314	rc = nvram_write_header(part);
	315	if (rc <= 0) {
	316	printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
	317	return rc;
	318	}
	319	list_del(&part->partition);
	320	kfree(part);
	321	} else
	322	prev = part;
1da177e4 LT	323	}
	324
	325	return 0;
	326	}
	327
4e7c77a3 BH	328	/**
	329	* nvram_create_partition - Create a partition in nvram
	330	* @name: name of the partition to create
	331	* @sig: signature of the partition to create
36673307	332	* @req_size: size of data to allocate in bytes
4e7c77a3	333	* @min_size: minimum acceptable size (0 means req_size)
e49e2e87 BH	334	*
	335	* Returns a negative error code or a positive nvram index
	336	* of the beginning of the data area of the newly created
	337	* partition. If you provided a min_size smaller than req_size
	338	* you need to query for the actual size yourself after the
	339	* call using nvram_partition_get_size().
1da177e4	340	*/
edc79a2f BH	341	loff_t __init nvram_create_partition(const char *name, int sig,
edc79a2f BH	342	int req_size, int min_size)
1da177e4	343	{
a341ad97 AB	344	struct nvram_partition *part;
a341ad97 AB	345	struct nvram_partition *new_part;
0339ad77	346	struct nvram_partition *free_part = NULL;
cef0d5ad	347	static char nv_init_vals[16];
1da177e4 LT	348	loff_t tmp_index;
	349	long size = 0;
	350	int rc;
4e7c77a3	351
36673307 BH	352	/* Convert sizes from bytes to blocks */
	353	req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	354	min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	355
4e7c77a3 BH	356	/* If no minimum size specified, make it the same as the
	357	* requested size
	358	*/
	359	if (min_size == 0)
	360	min_size = req_size;
e49e2e87 BH	361	if (min_size > req_size)
e49e2e87 BH	362	return -EINVAL;
4e7c77a3	363
36673307 BH	364	/* Now add one block to each for the header */
	365	req_size += 1;
	366	min_size += 1;
	367
1da177e4 LT	368	/* Find a free partition that will give us the maximum needed size
1da177e4 LT	369	If can't find one that will give us the minimum size needed */
690d1a9b	370	list_for_each_entry(part, &nvram_partitions, partition) {
1da177e4 LT	371	if (part->header.signature != NVRAM_SIG_FREE)
	372	continue;
	373
4e7c77a3 BH	374	if (part->header.length >= req_size) {
4e7c77a3 BH	375	size = req_size;
1da177e4 LT	376	free_part = part;
	377	break;
	378	}
4e7c77a3 BH	379	if (part->header.length > size &&
	380	part->header.length >= min_size) {
	381	size = part->header.length;
1da177e4 LT	382	free_part = part;
	383	}
	384	}
0339ad77	385	if (!size)
1da177e4	386	return -ENOSPC;
1da177e4 LT	387
1da177e4 LT	388	/* Create our OS partition */
0339ad77	389	new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1da177e4	390	if (!new_part) {
e49e2e87	391	pr_err("nvram_create_os_partition: kmalloc failed\n");
1da177e4 LT	392	return -ENOMEM;
	393	}
	394
	395	new_part->index = free_part->index;
4e7c77a3	396	new_part->header.signature = sig;
1da177e4	397	new_part->header.length = size;
4e7c77a3	398	strncpy(new_part->header.name, name, 12);
1da177e4 LT	399	new_part->header.checksum = nvram_checksum(&new_part->header);
	400
	401	rc = nvram_write_header(new_part);
	402	if (rc <= 0) {
e49e2e87 BH	403	pr_err("nvram_create_os_partition: nvram_write_header "
e49e2e87 BH	404	"failed (%d)\n", rc);
1da177e4 LT	405	return rc;
1da177e4 LT	406	}
e49e2e87 BH	407	list_add_tail(&new_part->partition, &free_part->partition);
	408
	409	/* Adjust or remove the partition we stole the space from */
	410	if (free_part->header.length > size) {
	411	free_part->index += size * NVRAM_BLOCK_LEN;
	412	free_part->header.length -= size;
	413	free_part->header.checksum = nvram_checksum(&free_part->header);
	414	rc = nvram_write_header(free_part);
	415	if (rc <= 0) {
	416	pr_err("nvram_create_os_partition: nvram_write_header "
	417	"failed (%d)\n", rc);
	418	return rc;
	419	}
	420	} else {
	421	list_del(&free_part->partition);
	422	kfree(free_part);
	423	}
1da177e4	424
e49e2e87	425	/* Clear the new partition */
cef0d5ad BH	426	for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
	427	tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
	428	tmp_index += NVRAM_BLOCK_LEN) {
	429	rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
	430	if (rc <= 0) {
	431	pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
	432	return rc;
	433	}
1da177e4 LT	434	}
1da177e4 LT	435
e49e2e87 BH	436	return new_part->index + NVRAM_HEADER_LEN;
e49e2e87 BH	437	}
1da177e4	438
e49e2e87 BH	439	/**
	440	* nvram_get_partition_size - Get the data size of an nvram partition
	441	* @data_index: This is the offset of the start of the data of
	442	* the partition. The same value that is returned by
	443	* nvram_create_partition().
	444	*/
edc79a2f	445	int nvram_get_partition_size(loff_t data_index)
e49e2e87 BH	446	{
e49e2e87 BH	447	struct nvram_partition *part;
1da177e4	448
690d1a9b	449	list_for_each_entry(part, &nvram_partitions, partition) {
e49e2e87 BH	450	if (part->index + NVRAM_HEADER_LEN == data_index)
e49e2e87 BH	451	return (part->header.length - 1) * NVRAM_BLOCK_LEN;
1da177e4	452	}
e49e2e87	453	return -1;
1da177e4 LT	454	}
	455
	456
cf5cbf9f BH	457	/**
	458	* nvram_find_partition - Find an nvram partition by signature and name
	459	* @name: Name of the partition or NULL for any name
	460	* @sig: Signature to test against
	461	* @out_size: if non-NULL, returns the size of the data part of the partition
	462	*/
	463	loff_t nvram_find_partition(const char name, int sig, int out_size)
	464	{
	465	struct nvram_partition *p;
	466
690d1a9b	467	list_for_each_entry(p, &nvram_partitions, partition) {
cf5cbf9f BH	468	if (p->header.signature == sig &&
	469	(!name \|\| !strncmp(p->header.name, name, 12))) {
	470	if (out_size)
	471	out_size = (p->header.length - 1)
	472	NVRAM_BLOCK_LEN;
	473	return p->index + NVRAM_HEADER_LEN;
	474	}
	475	}
	476	return 0;
	477	}
	478
edc79a2f	479	int __init nvram_scan_partitions(void)
1da177e4 LT	480	{
	481	loff_t cur_index = 0;
	482	struct nvram_header phead;
	483	struct nvram_partition * tmp_part;
	484	unsigned char c_sum;
	485	char * header;
	486	int total_size;
	487	int err;
	488
edc79a2f	489	if (ppc_md.nvram_size == NULL \|\| ppc_md.nvram_size() <= 0)
1da177e4 LT	490	return -ENODEV;
	491	total_size = ppc_md.nvram_size();
	492
5cbded58	493	header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1da177e4 LT	494	if (!header) {
	495	printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
	496	return -ENOMEM;
	497	}
	498
	499	while (cur_index < total_size) {
	500
	501	err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
	502	if (err != NVRAM_HEADER_LEN) {
	503	printk(KERN_ERR "nvram_scan_partitions: Error parsing "
	504	"nvram partitions\n");
	505	goto out;
	506	}
	507
	508	cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
	509
	510	memcpy(&phead, header, NVRAM_HEADER_LEN);
	511
c81095a4 CLG	512	phead.length = be16_to_cpu(phead.length);
c81095a4 CLG	513
1da177e4 LT	514	err = 0;
	515	c_sum = nvram_checksum(&phead);
	516	if (c_sum != phead.checksum) {
	517	printk(KERN_WARNING "WARNING: nvram partition checksum"
	518	" was %02x, should be %02x!\n",
	519	phead.checksum, c_sum);
	520	printk(KERN_WARNING "Terminating nvram partition scan\n");
	521	goto out;
	522	}
	523	if (!phead.length) {
	524	printk(KERN_WARNING "WARNING: nvram corruption "
	525	"detected: 0-length partition\n");
	526	goto out;
	527	}
6e51c9ff	528	tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
1da177e4 LT	529	err = -ENOMEM;
	530	if (!tmp_part) {
	531	printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
	532	goto out;
	533	}
	534
	535	memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
	536	tmp_part->index = cur_index;
690d1a9b	537	list_add_tail(&tmp_part->partition, &nvram_partitions);
1da177e4 LT	538
	539	cur_index += phead.length * NVRAM_BLOCK_LEN;
	540	}
	541	err = 0;
	542
edc79a2f BH	543	#ifdef DEBUG_NVRAM
	544	nvram_print_partitions("NVRAM Partitions");
	545	#endif
	546
1da177e4 LT	547	out:
	548	kfree(header);
	549	return err;
	550	}
	551
	552	static int __init nvram_init(void)
	553	{
1da177e4 LT	554	int rc;
1da177e4 LT	555
578914cf BH	556	BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
578914cf BH	557
1da177e4 LT	558	if (ppc_md.nvram_size == NULL \|\| ppc_md.nvram_size() <= 0)
	559	return -ENODEV;
	560
	561	rc = misc_register(&nvram_dev);
	562	if (rc != 0) {
	563	printk(KERN_ERR "nvram_init: failed to register device\n");
	564	return rc;
	565	}
	566
1da177e4 LT	567	return rc;
	568	}
	569
e51df2c1	570	static void __exit nvram_cleanup(void)
1da177e4 LT	571	{
	572	misc_deregister( &nvram_dev );
	573	}
	574
1da177e4 LT	575	module_init(nvram_init);
	576	module_exit(nvram_cleanup);
	577	MODULE_LICENSE("GPL");