[PATCH v3 2/4] block: partitions: populate fwnode

Daniel Golle
2024-06-26T02:51:13Z

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@makrotopia.org>
---
block/partitions/core.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/block/partitions/core.c b/block/partitions/core.c
index ab76e64f0f6c..f88829e254e6 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 +283,42 @@ static ssize_t whole_disk_show(struct device *dev,
}
static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);

+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;
+
+ fw_parts = device_get_named_child_node(ddev, "partitions");
+ if (!fw_parts)
+ fw_parts = device_get_named_child_node(ddev->parent, "partitions");
+
+ if (!fw_parts)
+ return NULL;
+
+ fwnode_for_each_child_node(fw_parts, fw_part) {
+ if (!fwnode_property_read_string(fw_part, "uuid", &uuid) &&
+ (!bdev->bd_meta_info || strlen(uuid) > PARTITION_META_INFO_UUIDLTH ||
+ strncmp(uuid, bdev->bd_meta_info->uuid, PARTITION_META_INFO_UUIDLTH)))
+ continue;
+
+ if (!fwnode_property_read_string(fw_part, "partname", &partname) &&
+ (!bdev->bd_meta_info || strlen(uuid) > PARTITION_META_INFO_VOLNAMELTH ||
+ strncmp(partname, bdev->bd_meta_info->volname,
+ PARTITION_META_INFO_VOLNAMELTH)))
+ continue;
+
+ if (!fwnode_property_read_u32(fw_part, "partno", &partno) &&
+ bdev_partno(bdev) != 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 +393,8 @@ 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