nvram_64.c

linux-2.6.15.6

	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 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 == PLATFORM_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_os_partition();
	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 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 = (char *) 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 = (struct nvram_partition *) 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)
{
	int rc;
	loff_t tmp_index;
	struct err_log_info info;
	
	if (no_logging) {
		return -EPERM;
	}

	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)
{
	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;

	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");