[mirror_ubuntu-zesty-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 16 /* sizeof(struct nvram_header) */
#define NVRAM_BLOCK_LEN 16
#define NVRAM_MAX_REQ (2080/NVRAM_BLOCK_LEN)
#define NVRAM_MIN_REQ (1056/NVRAM_BLOCK_LEN)

/* If change this size, then change the size of NVNAME_LEN */
struct nvram_header {
	unsigned char signature;
	unsigned char checksum;
	unsigned short length;
	char name[12];
};

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

static struct nvram_partition * nvram_part;
static long nvram_error_log_index = -1;
static long nvram_error_log_size = 0;

struct err_log_info {
	int error_type;
	unsigned int seq_num;
};

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 list_head * p;
	struct nvram_partition * tmp_part;
	
	printk(KERN_WARNING "--------%s---------\n", label);
	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
	list_for_each(p, &nvram_part->partition) {
		tmp_part = list_entry(p, struct nvram_partition, partition);
		printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%s\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;
}

static int __init nvram_remove_os_partition(void)
{
	struct list_head *i;
	struct list_head *j;
	struct nvram_partition * part;
	struct nvram_partition * cur_part;
	int rc;

	list_for_each(i, &nvram_part->partition) {
		part = list_entry(i, struct nvram_partition, partition);
		if (part->header.signature != NVRAM_SIG_OS)
			continue;
		
		/* Make os partition a free partition */
		part->header.signature = NVRAM_SIG_FREE;
		sprintf(part->header.name, "wwwwwwwwwwww");
		part->header.checksum = nvram_checksum(&part->header);

		/* Merge contiguous free partitions backwards */
		list_for_each_prev(j, &part->partition) {
			cur_part = list_entry(j, struct nvram_partition, partition);
			if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
				break;
			}
			
			part->header.length += cur_part->header.length;
			part->header.checksum = nvram_checksum(&part->header);
			part->index = cur_part->index;

			list_del(&cur_part->partition);
			kfree(cur_part);
			j = &part->partition; /* fixup our loop */
		}
		
		/* Merge contiguous free partitions forwards */
		list_for_each(j, &part->partition) {
			cur_part = list_entry(j, struct nvram_partition, partition);
			if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
				break;
			}

			part->header.length += cur_part->header.length;
			part->header.checksum = nvram_checksum(&part->header);

			list_del(&cur_part->partition);
			kfree(cur_part);
			j = &part->partition; /* fixup our loop */
		}
		
		rc = nvram_write_header(part);
		if (rc <= 0) {
			printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
			return rc;
		}

	}
	
	return 0;
}

/* nvram_create_os_partition
 *
 * Create a OS linux partition to buffer error logs.
 * Will create a partition starting at the first free
 * space found if space has enough room.
 */
static int __init nvram_create_os_partition(void)
{
	struct nvram_partition *part;
	struct nvram_partition *new_part;
	struct nvram_partition *free_part = NULL;
	int seq_init[2] = { 0, 0 };
	loff_t tmp_index;
	long size = 0;
	int rc;
	
	/* 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_part->partition, partition) {
		if (part->header.signature != NVRAM_SIG_FREE)
			continue;

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

	new_part->index = free_part->index;
	new_part->header.signature = NVRAM_SIG_OS;
	new_part->header.length = size;
	strcpy(new_part->header.name, "ppc64,linux");
	new_part->header.checksum = nvram_checksum(&new_part->header);

	rc = nvram_write_header(new_part);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
				"failed (%d)\n", rc);
		return rc;
	}

	/* make sure and initialize to zero the sequence number and the error
	   type logged */
	tmp_index = new_part->index + NVRAM_HEADER_LEN;
	rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_create_os_partition: nvram_write "
		       "failed (%d)\n", rc);
		return rc;
	}
	
	nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
	nvram_error_log_size = ((part->header.length - 1) *
				NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
	
	list_add_tail(&new_part->partition, &free_part->partition);

	if (free_part->header.length <= size) {
		list_del(&free_part->partition);
		kfree(free_part);
		return 0;
	} 

	/* Adjust the partition we stole the space from */
	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) {
		printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
		       "failed (%d)\n", rc);
		return rc;
	}

	return 0;
}


/* nvram_setup_partition
 *
 * This will setup the partition we need for buffering the
 * error logs and cleanup partitions if needed.
 *
 * The general strategy is the following:
 * 1.) If there is ppc64,linux partition large enough then use it.
 * 2.) If there is not a ppc64,linux partition large enough, search
 * for a free partition that is large enough.
 * 3.) If there is not a free partition large enough remove 
 * _all_ OS partitions and consolidate the space.
 * 4.) Will first try getting a chunk that will satisfy the maximum
 * error log size (NVRAM_MAX_REQ).
 * 5.) If the max chunk cannot be allocated then try finding a chunk
 * that will satisfy the minum needed (NVRAM_MIN_REQ).
 */
static int __init nvram_setup_partition(void)
{
	struct list_head * p;
	struct nvram_partition * part;
	int rc;

	/* For now, we don't do any of this on pmac, until I
	 * have figured out if it's worth killing some unused stuffs
	 * in our nvram, as Apple defined partitions use pretty much
	 * all of the space
	 */
	if (machine_is(powermac))
		return -ENOSPC;

	/* see if we have an OS partition that meets our needs.
	   will try getting the max we need.  If not we'll delete
	   partitions and try again. */
	list_for_each(p, &nvram_part->partition) {
		part = list_entry(p, struct nvram_partition, partition);
		if (part->header.signature != NVRAM_SIG_OS)
			continue;

		if (strcmp(part->header.name, "ppc64,linux"))
			continue;

		if (part->header.length >= NVRAM_MIN_REQ) {
			/* found our partition */
			nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
			nvram_error_log_size = ((part->header.length - 1) *
						NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
			return 0;
		}
	}
	
	/* try creating a partition with the free space we have */
	rc = nvram_create_partition("ppc64,linux", );
	if (!rc) {
		return 0;
	}
		
	/* need to free up some space */
	rc = nvram_remove_os_partition();
	if (rc) {
		return rc;
	}
	
	/* create a partition in this new space */
	rc = nvram_create_os_partition();
	if (rc) {
		printk(KERN_ERR "nvram_create_os_partition: Could not find a "
		       "NVRAM partition large enough\n");
		return rc;
	}
	
	return 0;
}


static 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)
		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_part->partition);
		
		cur_index += phead.length * NVRAM_BLOCK_LEN;
	}
	err = 0;

 out:
	kfree(header);
	return err;
}

static int __init nvram_init(void)
{
	int error;
	int rc;
	
	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;
	}
  	
  	/* initialize our anchor for the nvram partition list */
  	nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
  	if (!nvram_part) {
  		printk(KERN_ERR "nvram_init: Failed kmalloc\n");
  		return -ENOMEM;
  	}
  	INIT_LIST_HEAD(&nvram_part->partition);
  
  	/* Get all the NVRAM partitions */
  	error = nvram_scan_partitions();
  	if (error) {
  		printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
  		return error;
  	}
  		
  	if(nvram_setup_partition()) 
  		printk(KERN_WARNING "nvram_init: Could not find nvram partition"
  		       " for nvram buffered error logging.\n");
  
#ifdef DEBUG_NVRAM
	nvram_print_partitions("NVRAM Partitions");
#endif

  	return rc;
}

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


#ifdef CONFIG_PPC_PSERIES

/* nvram_write_error_log
 *
 * We need to buffer the error logs into nvram to ensure that we have
 * the failure information to decode.  If we have a severe error there
 * is no way to guarantee that the OS or the machine is in a state to
 * get back to user land and write the error to disk.  For example if
 * the SCSI device driver causes a Machine Check by writing to a bad
 * IO address, there is no way of guaranteeing that the device driver
 * is in any state that is would also be able to write the error data
 * captured to disk, thus we buffer it in NVRAM for analysis on the
 * next boot.
 *
 * In NVRAM the partition containing the error log buffer will looks like:
 * Header (in bytes):
 * +-----------+----------+--------+------------+------------------+
 * | signature | checksum | length | name       | data             |
 * |0          |1         |2      3|4         15|16        length-1|
 * +-----------+----------+--------+------------+------------------+
 *
 * The 'data' section would look like (in bytes):
 * +--------------+------------+-----------------------------------+
 * | event_logged | sequence # | error log                         |
 * |0            3|4          7|8            nvram_error_log_size-1|
 * +--------------+------------+-----------------------------------+
 *
 * event_logged: 0 if event has not been logged to syslog, 1 if it has
 * sequence #: The unique sequence # for each event. (until it wraps)
 * error log: The error log from event_scan
 */
int nvram_write_error_log(char * buff, int length,
                          unsigned int err_type, unsigned int error_log_cnt)
{
	int rc;
	loff_t tmp_index;
	struct err_log_info info;
	
	if (nvram_error_log_index == -1) {
		return -ESPIPE;
	}

	if (length > nvram_error_log_size) {
		length = nvram_error_log_size;
	}

	info.error_type = err_type;
	info.seq_num = error_log_cnt;

	tmp_index = nvram_error_log_index;

	rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
		return rc;
	}

	rc = ppc_md.nvram_write(buff, length, &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
		return rc;
	}
	
	return 0;
}

/* nvram_read_error_log
 *
 * Reads nvram for error log for at most 'length'
 */
int nvram_read_error_log(char * buff, int length,
                         unsigned int * err_type, unsigned int * error_log_cnt)
{
	int rc;
	loff_t tmp_index;
	struct err_log_info info;
	
	if (nvram_error_log_index == -1)
		return -1;

	if (length > nvram_error_log_size)
		length = nvram_error_log_size;

	tmp_index = nvram_error_log_index;

	rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
		return rc;
	}

	rc = ppc_md.nvram_read(buff, length, &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
		return rc;
	}

	*error_log_cnt = info.seq_num;
	*err_type = info.error_type;

	return 0;
}

/* This doesn't actually zero anything, but it sets the event_logged
 * word to tell that this event is safely in syslog.
 */
int nvram_clear_error_log(void)
{
	loff_t tmp_index;
	int clear_word = ERR_FLAG_ALREADY_LOGGED;
	int rc;

	if (nvram_error_log_index == -1)
		return -1;

	tmp_index = nvram_error_log_index;
	
	rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
		return rc;
	}

	return 0;
}

#endif /* CONFIG_PPC_PSERIES */

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
74d51d02 BH	37	#define NVRAM_HEADER_LEN 16 /* sizeof(struct nvram_header) */
	38	#define NVRAM_BLOCK_LEN 16
	39	#define NVRAM_MAX_REQ (2080/NVRAM_BLOCK_LEN)
	40	#define NVRAM_MIN_REQ (1056/NVRAM_BLOCK_LEN)
	41
	42	/* If change this size, then change the size of NVNAME_LEN */
	43	struct nvram_header {
	44	unsigned char signature;
	45	unsigned char checksum;
	46	unsigned short length;
	47	char name[12];
	48	};
	49
	50	struct nvram_partition {
	51	struct list_head partition;
	52	struct nvram_header header;
	53	unsigned int index;
	54	};
	55
1da177e4 LT	56	static struct nvram_partition * nvram_part;
	57	static long nvram_error_log_index = -1;
	58	static long nvram_error_log_size = 0;
	59
1da177e4 LT	60	struct err_log_info {
	61	int error_type;
	62	unsigned int seq_num;
	63	};
	64
	65	static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
	66	{
	67	int size;
	68
	69	if (ppc_md.nvram_size == NULL)
	70	return -ENODEV;
	71	size = ppc_md.nvram_size();
	72
	73	switch (origin) {
	74	case 1:
	75	offset += file->f_pos;
	76	break;
	77	case 2:
	78	offset += size;
	79	break;
	80	}
	81	if (offset < 0)
	82	return -EINVAL;
	83	file->f_pos = offset;
	84	return file->f_pos;
	85	}
	86
	87
	88	static ssize_t dev_nvram_read(struct file file, char __user buf,
	89	size_t count, loff_t *ppos)
	90	{
f9ce299f AB	91	ssize_t ret;
	92	char *tmp = NULL;
	93	ssize_t size;
1da177e4	94
f9ce299f AB	95	ret = -ENODEV;
	96	if (!ppc_md.nvram_size)
	97	goto out;
	98
	99	ret = 0;
1da177e4	100	size = ppc_md.nvram_size();
f9ce299f AB	101	if (*ppos >= size \|\| size < 0)
f9ce299f AB	102	goto out;
1da177e4	103
f9ce299f AB	104	count = min_t(size_t, count, size - *ppos);
f9ce299f AB	105	count = min(count, PAGE_SIZE);
1da177e4	106
f9ce299f AB	107	ret = -ENOMEM;
	108	tmp = kmalloc(count, GFP_KERNEL);
	109	if (!tmp)
	110	goto out;
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 LT	207	{
	208	struct list_head * p;
	209	struct nvram_partition * tmp_part;
	210
	211	printk(KERN_WARNING "--------%s---------\n", label);
	212	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
	213	list_for_each(p, &nvram_part->partition) {
	214	tmp_part = list_entry(p, struct nvram_partition, partition);
5a43ee65	215	printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%s\n",
1da177e4 LT	216	tmp_part->index, tmp_part->header.signature,
	217	tmp_part->header.checksum, tmp_part->header.length,
	218	tmp_part->header.name);
	219	}
	220	}
	221	#endif
	222
	223
32c105c3	224	static int __init nvram_write_header(struct nvram_partition * part)
1da177e4 LT	225	{
	226	loff_t tmp_index;
	227	int rc;
	228
	229	tmp_index = part->index;
	230	rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
	231
	232	return rc;
	233	}
	234
	235
32c105c3	236	static unsigned char __init nvram_checksum(struct nvram_header *p)
1da177e4 LT	237	{
	238	unsigned int c_sum, c_sum2;
	239	unsigned short sp = (unsigned short )p->name; /* assume 6 shorts */
	240	c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
	241
	242	/* The sum may have spilled into the 3rd byte. Fold it back. */
	243	c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
	244	/* The sum cannot exceed 2 bytes. Fold it into a checksum */
	245	c_sum2 = (c_sum >> 8) + (c_sum << 8);
	246	c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
	247	return c_sum;
	248	}
	249
32c105c3	250	static int __init nvram_remove_os_partition(void)
1da177e4 LT	251	{
	252	struct list_head *i;
	253	struct list_head *j;
	254	struct nvram_partition * part;
	255	struct nvram_partition * cur_part;
	256	int rc;
	257
	258	list_for_each(i, &nvram_part->partition) {
	259	part = list_entry(i, struct nvram_partition, partition);
	260	if (part->header.signature != NVRAM_SIG_OS)
	261	continue;
	262
	263	/* Make os partition a free partition */
	264	part->header.signature = NVRAM_SIG_FREE;
	265	sprintf(part->header.name, "wwwwwwwwwwww");
	266	part->header.checksum = nvram_checksum(&part->header);
	267
	268	/* Merge contiguous free partitions backwards */
	269	list_for_each_prev(j, &part->partition) {
	270	cur_part = list_entry(j, struct nvram_partition, partition);
	271	if (cur_part == nvram_part \|\| cur_part->header.signature != NVRAM_SIG_FREE) {
	272	break;
	273	}
	274
	275	part->header.length += cur_part->header.length;
	276	part->header.checksum = nvram_checksum(&part->header);
	277	part->index = cur_part->index;
	278
	279	list_del(&cur_part->partition);
	280	kfree(cur_part);
	281	j = &part->partition; /* fixup our loop */
	282	}
	283
	284	/* Merge contiguous free partitions forwards */
	285	list_for_each(j, &part->partition) {
	286	cur_part = list_entry(j, struct nvram_partition, partition);
	287	if (cur_part == nvram_part \|\| cur_part->header.signature != NVRAM_SIG_FREE) {
	288	break;
	289	}
	290
	291	part->header.length += cur_part->header.length;
	292	part->header.checksum = nvram_checksum(&part->header);
	293
	294	list_del(&cur_part->partition);
	295	kfree(cur_part);
	296	j = &part->partition; /* fixup our loop */
	297	}
	298
	299	rc = nvram_write_header(part);
	300	if (rc <= 0) {
	301	printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
	302	return rc;
	303	}
	304
	305	}
	306
	307	return 0;
	308	}
	309
	310	/* nvram_create_os_partition
	311	*
	312	* Create a OS linux partition to buffer error logs.
	313	* Will create a partition starting at the first free
	314	* space found if space has enough room.
315	*/
32c105c3	316	static int __init nvram_create_os_partition(void)
1da177e4	317	{
a341ad97 AB	318	struct nvram_partition *part;
a341ad97 AB	319	struct nvram_partition *new_part;
0339ad77	320	struct nvram_partition *free_part = NULL;
1da177e4 LT	321	int seq_init[2] = { 0, 0 };
	322	loff_t tmp_index;
	323	long size = 0;
	324	int rc;
	325
	326	/* Find a free partition that will give us the maximum needed size
	327	If can't find one that will give us the minimum size needed */
a341ad97	328	list_for_each_entry(part, &nvram_part->partition, partition) {
1da177e4 LT	329	if (part->header.signature != NVRAM_SIG_FREE)
	330	continue;
	331
	332	if (part->header.length >= NVRAM_MAX_REQ) {
	333	size = NVRAM_MAX_REQ;
	334	free_part = part;
	335	break;
	336	}
	337	if (!size && part->header.length >= NVRAM_MIN_REQ) {
	338	size = NVRAM_MIN_REQ;
	339	free_part = part;
	340	}
	341	}
0339ad77	342	if (!size)
1da177e4	343	return -ENOSPC;
1da177e4 LT	344
1da177e4 LT	345	/* Create our OS partition */
0339ad77	346	new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1da177e4 LT	347	if (!new_part) {
	348	printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
	349	return -ENOMEM;
	350	}
	351
	352	new_part->index = free_part->index;
	353	new_part->header.signature = NVRAM_SIG_OS;
	354	new_part->header.length = size;
0339ad77	355	strcpy(new_part->header.name, "ppc64,linux");
1da177e4 LT	356	new_part->header.checksum = nvram_checksum(&new_part->header);
	357
	358	rc = nvram_write_header(new_part);
	359	if (rc <= 0) {
5a2ad98e JP	360	printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
5a2ad98e JP	361	"failed (%d)\n", rc);
1da177e4 LT	362	return rc;
	363	}
	364
	365	/* make sure and initialize to zero the sequence number and the error
	366	type logged */
	367	tmp_index = new_part->index + NVRAM_HEADER_LEN;
	368	rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
	369	if (rc <= 0) {
0339ad77	370	printk(KERN_ERR "nvram_create_os_partition: nvram_write "
5a2ad98e	371	"failed (%d)\n", rc);
1da177e4 LT	372	return rc;
	373	}
	374
	375	nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
	376	nvram_error_log_size = ((part->header.length - 1) *
	377	NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
	378
	379	list_add_tail(&new_part->partition, &free_part->partition);
	380
	381	if (free_part->header.length <= size) {
	382	list_del(&free_part->partition);
	383	kfree(free_part);
	384	return 0;
	385	}
	386
	387	/* Adjust the partition we stole the space from */
	388	free_part->index += size * NVRAM_BLOCK_LEN;
	389	free_part->header.length -= size;
	390	free_part->header.checksum = nvram_checksum(&free_part->header);
	391
	392	rc = nvram_write_header(free_part);
	393	if (rc <= 0) {
	394	printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
	395	"failed (%d)\n", rc);
	396	return rc;
	397	}
	398
	399	return 0;
	400	}
	401
	402
	403	/* nvram_setup_partition
	404	*
	405	* This will setup the partition we need for buffering the
	406	* error logs and cleanup partitions if needed.
	407	*
	408	* The general strategy is the following:
	409	* 1.) If there is ppc64,linux partition large enough then use it.
	410	* 2.) If there is not a ppc64,linux partition large enough, search
	411	* for a free partition that is large enough.
	412	* 3.) If there is not a free partition large enough remove
	413	* _all_ OS partitions and consolidate the space.
	414	* 4.) Will first try getting a chunk that will satisfy the maximum
	415	* error log size (NVRAM_MAX_REQ).
	416	* 5.) If the max chunk cannot be allocated then try finding a chunk
	417	* that will satisfy the minum needed (NVRAM_MIN_REQ).
	418	*/
32c105c3	419	static int __init nvram_setup_partition(void)
1da177e4 LT	420	{
	421	struct list_head * p;
	422	struct nvram_partition * part;
	423	int rc;
	424
	425	/* For now, we don't do any of this on pmac, until I
	426	* have figured out if it's worth killing some unused stuffs
	427	* in our nvram, as Apple defined partitions use pretty much
	428	* all of the space
	429	*/
e8222502	430	if (machine_is(powermac))
1da177e4 LT	431	return -ENOSPC;
	432
	433	/* see if we have an OS partition that meets our needs.
	434	will try getting the max we need. If not we'll delete
	435	partitions and try again. */
	436	list_for_each(p, &nvram_part->partition) {
	437	part = list_entry(p, struct nvram_partition, partition);
	438	if (part->header.signature != NVRAM_SIG_OS)
	439	continue;
	440
	441	if (strcmp(part->header.name, "ppc64,linux"))
	442	continue;
	443
	444	if (part->header.length >= NVRAM_MIN_REQ) {
	445	/* found our partition */
	446	nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
	447	nvram_error_log_size = ((part->header.length - 1) *
	448	NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
	449	return 0;
	450	}
	451	}
	452
	453	/* try creating a partition with the free space we have */
74d51d02	454	rc = nvram_create_partition("ppc64,linux", );
1da177e4 LT	455	if (!rc) {
	456	return 0;
	457	}
	458
	459	/* need to free up some space */
	460	rc = nvram_remove_os_partition();
	461	if (rc) {
	462	return rc;
	463	}
	464
	465	/* create a partition in this new space */
	466	rc = nvram_create_os_partition();
	467	if (rc) {
	468	printk(KERN_ERR "nvram_create_os_partition: Could not find a "
	469	"NVRAM partition large enough\n");
	470	return rc;
	471	}
	472
	473	return 0;
	474	}
	475
	476
32c105c3	477	static int __init nvram_scan_partitions(void)
1da177e4 LT	478	{
	479	loff_t cur_index = 0;
	480	struct nvram_header phead;
	481	struct nvram_partition * tmp_part;
	482	unsigned char c_sum;
	483	char * header;
	484	int total_size;
	485	int err;
	486
	487	if (ppc_md.nvram_size == NULL)
	488	return -ENODEV;
	489	total_size = ppc_md.nvram_size();
	490
5cbded58	491	header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1da177e4 LT	492	if (!header) {
	493	printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
	494	return -ENOMEM;
	495	}
	496
	497	while (cur_index < total_size) {
	498
	499	err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
	500	if (err != NVRAM_HEADER_LEN) {
	501	printk(KERN_ERR "nvram_scan_partitions: Error parsing "
	502	"nvram partitions\n");
	503	goto out;
	504	}
	505
	506	cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
	507
	508	memcpy(&phead, header, NVRAM_HEADER_LEN);
	509
	510	err = 0;
	511	c_sum = nvram_checksum(&phead);
	512	if (c_sum != phead.checksum) {
	513	printk(KERN_WARNING "WARNING: nvram partition checksum"
	514	" was %02x, should be %02x!\n",
	515	phead.checksum, c_sum);
	516	printk(KERN_WARNING "Terminating nvram partition scan\n");
	517	goto out;
	518	}
	519	if (!phead.length) {
	520	printk(KERN_WARNING "WARNING: nvram corruption "
	521	"detected: 0-length partition\n");
	522	goto out;
	523	}
	524	tmp_part = (struct nvram_partition *)
	525	kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
	526	err = -ENOMEM;
	527	if (!tmp_part) {
	528	printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
	529	goto out;
	530	}
	531
	532	memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
	533	tmp_part->index = cur_index;
	534	list_add_tail(&tmp_part->partition, &nvram_part->partition);
	535
	536	cur_index += phead.length * NVRAM_BLOCK_LEN;
	537	}
	538	err = 0;
	539
	540	out:
	541	kfree(header);
	542	return err;
	543	}
	544
	545	static int __init nvram_init(void)
	546	{
	547	int error;
	548	int rc;
	549
	550	if (ppc_md.nvram_size == NULL \|\| ppc_md.nvram_size() <= 0)
	551	return -ENODEV;
	552
	553	rc = misc_register(&nvram_dev);
	554	if (rc != 0) {
	555	printk(KERN_ERR "nvram_init: failed to register device\n");
556	return rc;
557	}
558
559	/* initialize our anchor for the nvram partition list */
5cbded58	560	nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
1da177e4 LT	561	if (!nvram_part) {
	562	printk(KERN_ERR "nvram_init: Failed kmalloc\n");
	563	return -ENOMEM;
	564	}
	565	INIT_LIST_HEAD(&nvram_part->partition);
	566
	567	/* Get all the NVRAM partitions */
	568	error = nvram_scan_partitions();
	569	if (error) {
	570	printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
	571	return error;
	572	}
	573
	574	if(nvram_setup_partition())
	575	printk(KERN_WARNING "nvram_init: Could not find nvram partition"
	576	" for nvram buffered error logging.\n");
	577
	578	#ifdef DEBUG_NVRAM
	579	nvram_print_partitions("NVRAM Partitions");
	580	#endif
	581
	582	return rc;
	583	}
	584
	585	void __exit nvram_cleanup(void)
	586	{
	587	misc_deregister( &nvram_dev );
	588	}
	589
	590
	591	#ifdef CONFIG_PPC_PSERIES
	592
	593	/* nvram_write_error_log
	594	*
	595	* We need to buffer the error logs into nvram to ensure that we have
	596	* the failure information to decode. If we have a severe error there
	597	* is no way to guarantee that the OS or the machine is in a state to
	598	* get back to user land and write the error to disk. For example if
	599	* the SCSI device driver causes a Machine Check by writing to a bad
	600	* IO address, there is no way of guaranteeing that the device driver
	601	* is in any state that is would also be able to write the error data
	602	* captured to disk, thus we buffer it in NVRAM for analysis on the
	603	* next boot.
	604	*
	605	* In NVRAM the partition containing the error log buffer will looks like:
	606	* Header (in bytes):
	607	* +-----------+----------+--------+------------+------------------+
	608	* \| signature \| checksum \| length \| name \| data \|
	609	* \|0 \|1 \|2 3\|4 15\|16 length-1\|
	610	* +-----------+----------+--------+------------+------------------+
	611	*
	612	* The 'data' section would look like (in bytes):
	613	* +--------------+------------+-----------------------------------+
	614	* \| event_logged \| sequence # \| error log \|
	615	* \|0 3\|4 7\|8 nvram_error_log_size-1\|
	616	* +--------------+------------+-----------------------------------+
	617	*
	618	* event_logged: 0 if event has not been logged to syslog, 1 if it has
	619	* sequence #: The unique sequence # for each event. (until it wraps)
	620	* error log: The error log from event_scan
	621	*/
0f2342c8 LV	622	int nvram_write_error_log(char * buff, int length,
0f2342c8 LV	623	unsigned int err_type, unsigned int error_log_cnt)
1da177e4 LT	624	{
	625	int rc;
	626	loff_t tmp_index;
	627	struct err_log_info info;
	628
1da177e4 LT	629	if (nvram_error_log_index == -1) {
	630	return -ESPIPE;
	631	}
	632
	633	if (length > nvram_error_log_size) {
	634	length = nvram_error_log_size;
	635	}
	636
	637	info.error_type = err_type;
	638	info.seq_num = error_log_cnt;
	639
	640	tmp_index = nvram_error_log_index;
	641
	642	rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
	643	if (rc <= 0) {
	644	printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
	645	return rc;
	646	}
	647
	648	rc = ppc_md.nvram_write(buff, length, &tmp_index);
	649	if (rc <= 0) {
	650	printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
	651	return rc;
	652	}
	653
	654	return 0;
	655	}
	656
	657	/* nvram_read_error_log
	658	*
	659	* Reads nvram for error log for at most 'length'
	660	*/
0f2342c8 LV	661	int nvram_read_error_log(char * buff, int length,
0f2342c8 LV	662	unsigned int * err_type, unsigned int * error_log_cnt)
1da177e4 LT	663	{
	664	int rc;
	665	loff_t tmp_index;
	666	struct err_log_info info;
	667
	668	if (nvram_error_log_index == -1)
	669	return -1;
	670
	671	if (length > nvram_error_log_size)
	672	length = nvram_error_log_size;
	673
	674	tmp_index = nvram_error_log_index;
	675
	676	rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
	677	if (rc <= 0) {
	678	printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
	679	return rc;
	680	}
	681
	682	rc = ppc_md.nvram_read(buff, length, &tmp_index);
	683	if (rc <= 0) {
	684	printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
	685	return rc;
	686	}
	687
0f2342c8	688	*error_log_cnt = info.seq_num;
1da177e4 LT	689	*err_type = info.error_type;
	690
	691	return 0;
	692	}
	693
	694	/* This doesn't actually zero anything, but it sets the event_logged
	695	* word to tell that this event is safely in syslog.
	696	*/
	697	int nvram_clear_error_log(void)
	698	{
	699	loff_t tmp_index;
	700	int clear_word = ERR_FLAG_ALREADY_LOGGED;
	701	int rc;
	702
fd62c6c4 TG	703	if (nvram_error_log_index == -1)
	704	return -1;
	705
1da177e4 LT	706	tmp_index = nvram_error_log_index;
	707
	708	rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
	709	if (rc <= 0) {
	710	printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
	711	return rc;
	712	}
	713
	714	return 0;
	715	}
	716
	717	#endif /* CONFIG_PPC_PSERIES */
	718
	719	module_init(nvram_init);
	720	module_exit(nvram_cleanup);
	721	MODULE_LICENSE("GPL");