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Date: Tue, 5 Mar 2024 20:23:32 +0000
From: Daniel Golle <daniel@makrotopia.org>
To: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>, Jens Axboe <axboe@kernel.dk>,
	Daniel Golle <daniel@makrotopia.org>,
	Dave Chinner <dchinner@redhat.com>, Jan Kara <jack@suse.cz>,
	Thomas =?iso-8859-1?Q?Wei=DFschuh?= <linux@weissschuh.net>,
	Christian Brauner <brauner@kernel.org>,
	Li Lingfeng <lilingfeng3@huawei.com>,
	Damien Le Moal <dlemoal@kernel.org>, Min Li <min15.li@samsung.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Hannes Reinecke <hare@suse.de>,
	Christian Loehle <CLoehle@hyperstone.com>,
	Avri Altman <avri.altman@wdc.com>, Bean Huo <beanhuo@micron.com>,
	Yeqi Fu <asuk4.q@gmail.com>,
	Victor Shih <victor.shih@genesyslogic.com.tw>,
	Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	"Ricardo B. Marliere" <ricardo@marliere.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mmc@vger.kernel.org, linux-block@vger.kernel.org
Cc: Diping Zhang <diping.zhang@gl-inet.com>,
	Jianhui Zhao <zhaojh329@gmail.com>,
	Jieying Zeng <jieying.zeng@gl-inet.com>,
	Chad Monroe <chad.monroe@adtran.com>,
	Adam Fox <adam.fox@adtran.com>, John Crispin <john@phrozen.org>
Subject: [RFC PATCH v2 2/8] block: partitions: populate fwnode
Message-ID: <feaffcb7461718d76070d98406aab2298da1bbe3.1709667858.git.daniel@makrotopia.org>
References: <cover.1709667858.git.daniel@makrotopia.org>
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In-Reply-To: <cover.1709667858.git.daniel@makrotopia.org>

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 | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 5f5ed5c75f04d..48d7f01d76c6a 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 +283,43 @@ 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 || 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 || strncmp(partname,
+						    bdev->bd_meta_info->volname,
+						    PARTITION_META_INFO_VOLNAMELTH)))
+			continue;
+
+		if (!fwnode_property_read_u32(fw_part, "partno", &partno) &&
+		    bdev->bd_partno != 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 +394,8 @@ 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);
-- 
2.44.0