/*
   * Parse command line, get partition information
   *
   * Written by Cai Zhiyong <caizhiyong@huawei.com>
   *
   */
  #include <linux/export.h>
  #include <linux/cmdline-parser.h>
  
  static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
  {
  	int ret = 0;
  	struct cmdline_subpart *new_subpart;
  
  	*subpart = NULL;
  
  	new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
  	if (!new_subpart)
  		return -ENOMEM;
  
  	if (*partdef == '-') {
  		new_subpart->size = (sector_t)(~0ULL);
  		partdef++;
  	} else {
  		new_subpart->size = (sector_t)memparse(partdef, &partdef);
  		if (new_subpart->size < (sector_t)PAGE_SIZE) {
  			pr_warn("cmdline partition size is invalid.");
  			ret = -EINVAL;
  			goto fail;
  		}
  	}
  
  	if (*partdef == '@') {
  		partdef++;
  		new_subpart->from = (sector_t)memparse(partdef, &partdef);
  	} else {
  		new_subpart->from = (sector_t)(~0ULL);
  	}
  
  	if (*partdef == '(') {
  		int length;
  		char *next = strchr(++partdef, ')');
  
  		if (!next) {
  			pr_warn("cmdline partition format is invalid.");
  			ret = -EINVAL;
  			goto fail;
  		}
  
  		length = min_t(int, next - partdef,
  			       sizeof(new_subpart->name) - 1);
  		strncpy(new_subpart->name, partdef, length);
  		new_subpart->name[length] = '\0';
  
  		partdef = ++next;
  	} else
  		new_subpart->name[0] = '\0';
  
  	new_subpart->flags = 0;
  
  	if (!strncmp(partdef, "ro", 2)) {
  		new_subpart->flags |= PF_RDONLY;
  		partdef += 2;
  	}
  
  	if (!strncmp(partdef, "lk", 2)) {
  		new_subpart->flags |= PF_POWERUP_LOCK;
  		partdef += 2;
  	}
  
  	*subpart = new_subpart;
  	return 0;
  fail:
  	kfree(new_subpart);
  	return ret;
  }
  
  static void free_subpart(struct cmdline_parts *parts)
  {
  	struct cmdline_subpart *subpart;
  
  	while (parts->subpart) {
  		subpart = parts->subpart;
  		parts->subpart = subpart->next_subpart;
  		kfree(subpart);
  	}
  }
  
  static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
  {
  	int ret = -EINVAL;
  	char *next;
  	int length;
  	struct cmdline_subpart **next_subpart;
  	struct cmdline_parts *newparts;
  	char buf[BDEVNAME_SIZE + 32 + 4];
  
  	*parts = NULL;
  
  	newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
  	if (!newparts)
  		return -ENOMEM;
  
  	next = strchr(bdevdef, ':');
  	if (!next) {
  		pr_warn("cmdline partition has no block device.");
  		goto fail;
  	}
  
  	length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
  	strncpy(newparts->name, bdevdef, length);
  	newparts->name[length] = '\0';
  	newparts->nr_subparts = 0;
  
  	next_subpart = &newparts->subpart;
  
  	while (next && *(++next)) {
  		bdevdef = next;
  		next = strchr(bdevdef, ',');
  
  		length = (!next) ? (sizeof(buf) - 1) :
  			min_t(int, next - bdevdef, sizeof(buf) - 1);
  
  		strncpy(buf, bdevdef, length);
  		buf[length] = '\0';
  
  		ret = parse_subpart(next_subpart, buf);
  		if (ret)
  			goto fail;
  
  		newparts->nr_subparts++;
  		next_subpart = &(*next_subpart)->next_subpart;
  	}
  
  	if (!newparts->subpart) {
  		pr_warn("cmdline partition has no valid partition.");
  		ret = -EINVAL;
  		goto fail;
  	}
  
  	*parts = newparts;
  
  	return 0;
  fail:
  	free_subpart(newparts);
  	kfree(newparts);
  	return ret;
  }
  
  void cmdline_parts_free(struct cmdline_parts **parts)
  {
  	struct cmdline_parts *next_parts;
  
  	while (*parts) {
  		next_parts = (*parts)->next_parts;
  		free_subpart(*parts);
  		kfree(*parts);
  		*parts = next_parts;
  	}
  }
  EXPORT_SYMBOL(cmdline_parts_free);
  
  int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
  {
  	int ret;
  	char *buf;
  	char *pbuf;
  	char *next;
  	struct cmdline_parts **next_parts;
  
  	*parts = NULL;
  
  	next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	next_parts = parts;
  
  	while (next && *pbuf) {
  		next = strchr(pbuf, ';');
  		if (next)
  			*next = '\0';
  
  		ret = parse_parts(next_parts, pbuf);
  		if (ret)
  			goto fail;
  
  		if (next)
  			pbuf = ++next;
  
  		next_parts = &(*next_parts)->next_parts;
  	}
  
  	if (!*parts) {
  		pr_warn("cmdline partition has no valid partition.");
  		ret = -EINVAL;
  		goto fail;
  	}
  
  	ret = 0;
  done:
  	kfree(buf);
  	return ret;
  
  fail:
  	cmdline_parts_free(parts);
  	goto done;
  }
  EXPORT_SYMBOL(cmdline_parts_parse);
  
  struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
  					 const char *bdev)
  {
  	while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
  		parts = parts->next_parts;
  	return parts;
  }
  EXPORT_SYMBOL(cmdline_parts_find);
  
  /*
   *  add_part()
   *    0 success.
   *    1 can not add so many partitions.
   */
  int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
  		      int slot,
  		      int (*add_part)(int, struct cmdline_subpart *, void *),
  		      void *param)
  {
  	sector_t from = 0;
  	struct cmdline_subpart *subpart;
  
  	for (subpart = parts->subpart; subpart;
  	     subpart = subpart->next_subpart, slot++) {
  		if (subpart->from == (sector_t)(~0ULL))
  			subpart->from = from;
  		else
  			from = subpart->from;
  
  		if (from >= disk_size)
  			break;
  
  		if (subpart->size > (disk_size - from))
  			subpart->size = disk_size - from;
  
  		from += subpart->size;
  
  		if (add_part(slot, subpart, param))
  			break;
  	}
  
  	return slot;
  }
  EXPORT_SYMBOL(cmdline_parts_set);