scsi_devinfo.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 551 行 · 第 1/2 页

 * scsi_dev_info_list_add_str: parse dev_list and add to the
 * scsi_dev_info_list.
 * @dev_list:	string of device flags to add
 *
 * Description:
 * 	Parse dev_list, and add entries to the scsi_dev_info_list.
 * 	dev_list is of the form "vendor:product:flag,vendor:product:flag".
 * 	dev_list is modified via strsep. Can be called for command line
 * 	addition, for proc or mabye a sysfs interface.
 *
 * Returns: 0 if OK, -error on failure.
 **/
static int scsi_dev_info_list_add_str(char *dev_list)
{
	char *vendor, *model, *strflags, *next;
	char *next_check;
	int res = 0;

	next = dev_list;
	if (next && next[0] == '"') {
		/*
		 * Ignore both the leading and trailing quote.
		 */
		next++;
		next_check = ",\"";
	} else {
		next_check = ",";
	}

	/*
	 * For the leading and trailing '"' case, the for loop comes
	 * through the last time with vendor[0] == '\0'.
	 */
	for (vendor = strsep(&next, ":"); vendor && (vendor[0] != '\0')
	     && (res == 0); vendor = strsep(&next, ":")) {
		strflags = NULL;
		model = strsep(&next, ":");
		if (model)
			strflags = strsep(&next, next_check);
		if (!model || !strflags) {
			printk(KERN_ERR "%s: bad dev info string '%s' '%s'"
			       " '%s'\n", __FUNCTION__, vendor, model,
			       strflags);
			res = -EINVAL;
		} else
			res = scsi_dev_info_list_add(0 /* compatible */, vendor,
						     model, strflags, 0);
	}
	return res;
}

/**
 * get_device_flags - get device specific flags from the dynamic device
 * list. Called during scan time.
 * @vendor:	vendor name
 * @model:	model name
 *
 * Description:
 *     Search the scsi_dev_info_list for an entry matching @vendor and
 *     @model, if found, return the matching flags value, else return
 *     the host or global default settings.
 **/
int scsi_get_device_flags(struct scsi_device *sdev, unsigned char *vendor,
			  unsigned char *model)
{
	struct scsi_dev_info_list *devinfo;
	unsigned int bflags;

	bflags = sdev->sdev_bflags;
	if (!bflags)
		bflags = scsi_default_dev_flags;

	list_for_each_entry(devinfo, &scsi_dev_info_list, dev_info_list) {
		if (devinfo->compatible) {
			/*
			 * Behave like the older version of get_device_flags.
			 */
			size_t max;
			/*
			 * XXX why skip leading spaces? If an odd INQUIRY
			 * value, that should have been part of the
			 * scsi_static_device_list[] entry, such as "  FOO"
			 * rather than "FOO". Since this code is already
			 * here, and we don't know what device it is
			 * trying to work with, leave it as-is.
			 */
			max = 8;	/* max length of vendor */
			while ((max > 0) && *vendor == ' ') {
				max--;
				vendor++;
			}
			/*
			 * XXX removing the following strlen() would be
			 * good, using it means that for a an entry not in
			 * the list, we scan every byte of every vendor
			 * listed in scsi_static_device_list[], and never match
			 * a single one (and still have to compare at
			 * least the first byte of each vendor).
			 */
			if (memcmp(devinfo->vendor, vendor,
				    min(max, strlen(devinfo->vendor))))
				continue;
			/*
			 * Skip spaces again.
			 */
			max = 16;	/* max length of model */
			while ((max > 0) && *model == ' ') {
				max--;
				model++;
			}
			if (memcmp(devinfo->model, model,
				   min(max, strlen(devinfo->model))))
				continue;
			return devinfo->flags;
		} else {
			if (!memcmp(devinfo->vendor, vendor,
				     sizeof(devinfo->vendor)) &&
			     !memcmp(devinfo->model, model,
				      sizeof(devinfo->model)))
				return devinfo->flags;
		}
	}
	return bflags;
}

#ifdef CONFIG_SCSI_PROC_FS
/* 
 * proc_scsi_dev_info_read: dump the scsi_dev_info_list via
 * /proc/scsi/device_info
 */
static int proc_scsi_devinfo_read(char *buffer, char **start,
				  off_t offset, int length)
{
	struct scsi_dev_info_list *devinfo;
	int size, len = 0;
	off_t begin = 0;
	off_t pos = 0;

	list_for_each_entry(devinfo, &scsi_dev_info_list, dev_info_list) {
		size = sprintf(buffer + len, "'%.8s' '%.16s' 0x%x\n",
			devinfo->vendor, devinfo->model, devinfo->flags);
		len += size;
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
		if (pos > offset + length)
			goto stop_output;
	}

stop_output:
	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin);	/* Start slop */
	if (len > length)
		len = length;	/* Ending slop */
	return (len);
}

/* 
 * proc_scsi_dev_info_write: allow additions to the scsi_dev_info_list via
 * /proc.
 *
 * Use: echo "vendor:model:flag" > /proc/scsi/device_info
 *
 * To add a black/white list entry for vendor and model with an integer
 * value of flag to the scsi device info list.
 */
static int proc_scsi_devinfo_write(struct file *file, const char __user *buf,
				   unsigned long length, void *data)
{
	char *buffer;
	int err = length;

	if (!buf || length>PAGE_SIZE)
		return -EINVAL;
	if (!(buffer = (char *) __get_free_page(GFP_KERNEL)))
		return -ENOMEM;
	if (copy_from_user(buffer, buf, length)) {
		err =-EFAULT;
		goto out;
	}

	if (length < PAGE_SIZE)
		buffer[length] = '\0';
	else if (buffer[PAGE_SIZE-1]) {
		err = -EINVAL;
		goto out;
	}

	scsi_dev_info_list_add_str(buffer);

out:
	free_page((unsigned long)buffer);
	return err;
}
#endif /* CONFIG_SCSI_PROC_FS */

module_param_string(dev_flags, scsi_dev_flags, sizeof(scsi_dev_flags), 0);
MODULE_PARM_DESC(dev_flags,
	 "Given scsi_dev_flags=vendor:model:flags[,v:m:f] add black/white"
	 " list entries for vendor and model with an integer value of flags"
	 " to the scsi device info list");

module_param_named(default_dev_flags, scsi_default_dev_flags, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(default_dev_flags,
		 "scsi default device flag integer value");

/**
 * scsi_dev_info_list_delete: called from scsi.c:exit_scsi to remove
 * 	the scsi_dev_info_list.
 **/
void scsi_exit_devinfo(void)
{
	struct list_head *lh, *lh_next;
	struct scsi_dev_info_list *devinfo;

#ifdef CONFIG_SCSI_PROC_FS
	remove_proc_entry("scsi/device_info", NULL);
#endif

	list_for_each_safe(lh, lh_next, &scsi_dev_info_list) {
		devinfo = list_entry(lh, struct scsi_dev_info_list,
				     dev_info_list);
		kfree(devinfo);
	}
}

/**
 * scsi_dev_list_init: set up the dynamic device list.
 * @dev_list:	string of device flags to add
 *
 * Description:
 * 	Add command line @dev_list entries, then add
 * 	scsi_static_device_list entries to the scsi device info list.
 **/
int scsi_init_devinfo(void)
{
#ifdef CONFIG_SCSI_PROC_FS
	struct proc_dir_entry *p;
#endif
	int error, i;

	error = scsi_dev_info_list_add_str(scsi_dev_flags);
	if (error)
		return error;

	for (i = 0; scsi_static_device_list[i].vendor; i++) {
		error = scsi_dev_info_list_add(1 /* compatibile */,
				scsi_static_device_list[i].vendor,
				scsi_static_device_list[i].model,
				NULL,
				scsi_static_device_list[i].flags);
		if (error)
			goto out;
	}

#ifdef CONFIG_SCSI_PROC_FS
	p = create_proc_entry("scsi/device_info", 0, NULL);
	if (!p) {
		error = -ENOMEM;
		goto out;
	}

	p->owner = THIS_MODULE;
	p->get_info = proc_scsi_devinfo_read;
	p->write_proc = proc_scsi_devinfo_write;
#endif /* CONFIG_SCSI_PROC_FS */

 out:
	if (error)
		scsi_exit_devinfo();
	return error;
}