[PATCH v4 1/8] disk: Add partition lookup by type GUID functionality

[Balaji Selvanathan]

Introduce part_get_info_by_type_guid() function to enable partition
lookup using partition type GUID. This complements the existing UUID
lookup functionality and provides more flexible partition discovery
mechanisms.

Reviewed-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
---
Changes in v4:
- No changes

Changes in v3:
- Addressed minor corrections in part_get_info_by_type_guid function

Changes in v2:
- No changes
---
---
 disk/part.c    | 37 +++++++++++++++++++++++++++++++++++++
 include/part.h | 21 +++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/disk/part.c b/disk/part.c
index 4923dc44593..4cb3204ac6e 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -731,6 +731,43 @@ int part_get_info_by_uuid(struct blk_desc *desc, const char *uuid,
 	return -ENOENT;
 }
 
+int part_get_info_by_type_guid(struct blk_desc *desc, const char *type_guid,
+			       struct disk_partition *info)
+{
+	struct part_driver *part_drv;
+	int ret;
+	int i;
+
+	if (!CONFIG_IS_ENABLED(PARTITION_TYPE_GUID))
+		return -ENOENT;
+
+	part_drv = part_driver_lookup_type(desc);
+	if (!part_drv)
+		return -ENOENT;
+
+	for (i = 1; i <= part_drv->max_entries; i++) {
+		ret = part_driver_get_info(part_drv, desc, i, info);
+		if (ret) {
+			/* -ENOSYS means no ->get_info method. */
+			if (ret == -ENOSYS)
+				return ret;
+			/*
+			 * Partition with this index can't be obtained, but
+			 * further partitions might be, so keep checking.
+			 */
+			continue;
+		}
+
+		if (!strncasecmp(type_guid, disk_partition_type_guid(info),
+				 UUID_STR_LEN)) {
+			/* matched */
+			return i;
+		}
+	}
+
+	return -ENOENT;
+}
+
 /**
  * Get partition info from device number and partition name.
  *
diff --git a/include/part.h b/include/part.h
index 15daacd7faa..32614bd085b 100644
--- a/include/part.h
+++ b/include/part.h
@@ -327,6 +327,20 @@ int part_get_info_by_name(struct blk_desc *desc, const char *name,
 int part_get_info_by_uuid(struct blk_desc *desc, const char *uuid,
 			  struct disk_partition *info);
 
+/**
+ * part_get_info_by_type_guid() - Search for a partition by type GUID
+ *                                among all available registered partitions
+ *
+ * @desc:	block device descriptor
+ * @type_guid:	the specified partition type GUID
+ * @info:	the disk partition info
+ *
+ * Return: the partition number on match (starting on 1), -ENOENT on no match,
+ * otherwise error
+ */
+int part_get_info_by_type_guid(struct blk_desc *desc, const char *type_guid,
+			       struct disk_partition *info);
+
 /**
  * part_get_info_by_dev_and_name_or_num() - Get partition info from dev number
  *					    and part name, or dev number and
@@ -404,6 +418,13 @@ static inline int part_get_info_by_uuid(struct blk_desc *desc, const char *uuid,
 	return -ENOENT;
 }
 
+static inline int part_get_info_by_type_guid(struct blk_desc *desc,
+					     const char *type_guid,
+					     struct disk_partition *info)
+{
+	return -ENOENT;
+}
+
 static inline int
 part_get_info_by_dev_and_name_or_num(const char *dev_iface,
 				     const char *dev_part_str,

-- 
2.34.1