Let block partitions to be represented by a firmware node and hence
allow them to being referenced e.g. for use with blk-nvmem.
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
---
block/partitions/core.c | 70 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)
diff --git a/block/partitions/core.c b/block/partitions/core.c
index ab76e64f0f6c..edf582de741f 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -10,6 +10,8 @@
#include <linux/ctype.h>
#include <linux/vmalloc.h>
#include <linux/raid/detect.h>
+#include <linux/property.h>
+
#include "check.h"
static int (*const check_part[])(struct parsed_partitions *) = {
@@ -281,6 +283,72 @@ static ssize_t whole_disk_show(struct device *dev,
}
static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
+static bool part_meta_match(const char *attr, const char *member, size_t length)
+{
+ /* check if length of attr exceeds specified maximum length */
+ if (strnlen(attr, length) == length)
+ return false;
+
+ /* return true if strings match */
+ return !strncmp(attr, member, length);
+}
+
+static struct fwnode_handle *find_partition_fwnode(struct block_device *bdev)
+{
+ struct fwnode_handle *fw_parts, *fw_part;
+ struct device *ddev = disk_to_dev(bdev->bd_disk);
+ const char *partname, *uuid;
+ u32 partno;
+ bool got_uuid, got_partname, got_partno;
+
+ fw_parts = device_get_named_child_node(ddev, "partitions");
+ if (!fw_parts)
+ return NULL;
+
+ fwnode_for_each_child_node(fw_parts, fw_part) {
+ got_uuid = false;
+ got_partname = false;
+ got_partno = false;
+ /*
+ * In case 'uuid' is defined in the partitions firmware node require
+ * partition meta info being present and the specified uuid to match.
+ */
+ got_uuid = !fwnode_property_read_string(fw_part, "uuid", &uuid);
+ if (got_uuid && (!bdev->bd_meta_info ||
+ !part_meta_match(uuid, bdev->bd_meta_info->uuid,
+ PARTITION_META_INFO_UUIDLTH)))
+ continue;
+
+ /*
+ * In case 'partname' is defined in the partitions firmware node require
+ * partition meta info being present and the specified volname to match.
+ */
+ got_partname = !fwnode_property_read_string(fw_part, "partname",
+ &partname);
+ if (got_partname && (!bdev->bd_meta_info ||
+ !part_meta_match(partname,
+ bdev->bd_meta_info->volname,
+ PARTITION_META_INFO_VOLNAMELTH)))
+ continue;
+
+ /*
+ * In case 'partno' is defined in the partitions firmware node the
+ * specified partno needs to match.
+ */
+ got_partno = !fwnode_property_read_u32(fw_part, "partno", &partno);
+ if (got_partno && bdev_partno(bdev) != partno)
+ continue;
+
+ /* Skip if no matching criteria is present in firmware node */
+ if (!got_uuid && !got_partname && !got_partno)
+ continue;
+
+ return fw_part;
+ }
+
+ return NULL;
+}
+
/*
* Must be called either with open_mutex held, before a disk can be opened or
* after all disk users are gone.
@@ -355,6 +423,8 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
goto out_put;
}
+ device_set_node(pdev, find_partition_fwnode(bdev));
+
/* delay uevent until 'holders' subdir is created */
dev_set_uevent_suppress(pdev, 1);
err = device_add(pdev);
--
2.45.2
