diff mbox series

[v2,1/2] ramips: add Sercomm partition map parser

Message ID 20210225201800.2478284-2-jan@3e8.eu
State New
Headers show
Series ramips: use partition table on Netgear NAND devices | expand

Commit Message

Jan Hoffmann Feb. 25, 2021, 8:17 p.m. UTC
This adds an MTD partition parser for the Sercomm partition table that
is used in some Netgear routers.

This is essentially the same code as proposed in the pull request for
Netgear R6350 support by NOGUCHI Hiroshi <drvlabo@gmail.com>:
https://github.com/openwrt/openwrt/pull/1318

It was originally rejected as it did not seem to work correctly.
However, this was only due the NAND driver transparently shifting pages
to hide bad blocks, which was fixed in commit
527832e54bf3bc4d699a145ae66f34230246f0a9.

Signed-off-by: Jan Hoffmann <jan@3e8.eu>
---
 .../ramips/files/drivers/mtd/parsers/scpart.c | 257 ++++++++++++++++++
 .../patches-5.4/303-mtd-scpart-parser.patch   |  19 ++
 2 files changed, 276 insertions(+)
 create mode 100644 target/linux/ramips/files/drivers/mtd/parsers/scpart.c
 create mode 100644 target/linux/ramips/patches-5.4/303-mtd-scpart-parser.patch
diff mbox series

Patch

diff --git a/target/linux/ramips/files/drivers/mtd/parsers/scpart.c b/target/linux/ramips/files/drivers/mtd/parsers/scpart.c
new file mode 100644
index 0000000000..36c3c0bb36
--- /dev/null
+++ b/target/linux/ramips/files/drivers/mtd/parsers/scpart.c
@@ -0,0 +1,257 @@ 
+/*
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Sercomm/Netgear FLASH partition table.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/module.h>
+
+
+#define	MOD_NAME	"scpart"
+
+static const char sc_part_magic[] = {
+	'S', 'C', 'F', 'L', 'M', 'A', 'P', 'O', 'K', '\0',
+};
+#define	PART_MAGIC_LEN	sizeof(sc_part_magic)
+
+/* assumes that all fields are set by CPU native endian */
+struct sc_part_desc {
+	uint32_t	part_id;
+	uint32_t	part_offs;
+	uint32_t	part_bytes;
+};
+#define	ID_ALREADY_FOUND	(0xFFFFFFFFUL)
+
+#define	MAP_OFFS_IN_BLK	(0x800)
+
+#define	MAP_MIRROR_NUM	(2)
+
+static int scpart_desc_is_valid(struct sc_part_desc *pdesc)
+{
+	return !!((pdesc->part_id != 0xFFFFFFFFUL) &&
+			(pdesc->part_offs != 0xFFFFFFFFUL) &&
+			(pdesc->part_bytes != 0xFFFFFFFFUL));
+}
+
+static int scpart_scan_partmap(struct mtd_info *master, loff_t partmap_offs,
+				struct sc_part_desc **ppdesc)
+{
+	uint8_t *buf;
+	loff_t offs;
+	size_t retlen;
+	struct sc_part_desc *pdesc = NULL;
+	struct sc_part_desc *tmpdesc;
+	int cnt = 0;
+	int res2;
+	int res = 0;
+
+	buf = kzalloc(master->erasesize, GFP_KERNEL);
+	if (!buf) {
+		res = -ENOMEM;
+		goto out;
+	}
+
+	res2 = mtd_read(master, partmap_offs, master->erasesize, &retlen, buf);
+	if (res2 || (retlen != master->erasesize)) {
+		res = -EIO;
+		goto free;
+	}
+
+	offs = MAP_OFFS_IN_BLK;
+	while((offs + sizeof(*tmpdesc)) < master->erasesize) {
+		tmpdesc = (struct sc_part_desc*)&(buf[offs]);
+		if (!scpart_desc_is_valid(tmpdesc))
+			break;
+		cnt++;
+		offs += sizeof(*tmpdesc);
+	}
+
+	if (cnt > 0) {
+		int bytes = cnt * sizeof(*pdesc);
+
+		pdesc = kzalloc(bytes, GFP_KERNEL);
+		if (!pdesc) {
+			res = -ENOMEM;
+			goto free;
+		}
+		memcpy(pdesc, &(buf[MAP_OFFS_IN_BLK]), bytes);
+
+		*ppdesc = pdesc;
+		res = cnt;
+	}
+
+  free:
+	kfree(buf);
+
+  out:
+	return res;
+}
+
+static int scpart_find_partmap(struct mtd_info *master,
+				struct sc_part_desc **ppdesc)
+{
+	loff_t offs;
+	uint8_t rdbuf[PART_MAGIC_LEN];
+	size_t retlen;
+	int magic_found = 0;
+	int res2;
+	int res = 0;
+
+	offs = 0;
+	while((magic_found < MAP_MIRROR_NUM) &&
+			(offs < master->size) && !mtd_block_isbad(master, offs)) {
+		res2 = mtd_read(master, offs, PART_MAGIC_LEN, &retlen, rdbuf);
+		if (res2 || (retlen != PART_MAGIC_LEN)) {
+			res = -EIO;
+			goto out;
+		}
+		if (!memcmp(rdbuf, sc_part_magic, PART_MAGIC_LEN)) {
+			pr_debug("%s: signature found at 0x%llx\n", MOD_NAME, offs);
+			magic_found++;
+			res = scpart_scan_partmap(master, offs, ppdesc);
+			if (res > 0)
+				goto out;
+		}
+		offs += master->erasesize;
+	}
+
+  out:
+	if (res > 0)
+		pr_info("%s: valid 'SC PART MAP' found (%d partitions)\n", MOD_NAME, res);
+	else
+		pr_info("%s: no valid 'SC PART MAP'\n", MOD_NAME);
+
+	return res;
+}
+
+static int scpart_parse(struct mtd_info *master,
+			const struct mtd_partition **pparts,
+			struct mtd_part_parser_data *data)
+{
+	struct sc_part_desc *scpart_map = NULL;
+	struct mtd_partition *parts = NULL;
+	struct device_node *mtd_node;
+	struct device_node *ofpart_node;
+	struct device_node *pp;
+	const char *partname;
+	int nr_scparts;
+	int nr_parts = 0;
+	int n;
+	int res = 0;
+
+	mtd_node = mtd_get_of_node(master);
+	if (!mtd_node)
+		goto out;
+
+	ofpart_node = of_get_child_by_name(mtd_node, "partitions");
+	if (!ofpart_node)
+		goto out;
+
+	nr_scparts = scpart_find_partmap(master, &scpart_map);
+	if (nr_scparts <= 0) {
+		res = nr_scparts;
+		goto free;
+	}
+
+	for_each_child_of_node(ofpart_node, pp) {
+		u32 scpart_id;
+		struct mtd_partition *parts_tmp;
+
+		if(of_property_read_u32(pp, "scpart-id", &scpart_id))
+			continue;
+
+		for (n = 0 ; n < nr_scparts ; n++)
+			if ((scpart_map[n].part_id != ID_ALREADY_FOUND) &&
+					(scpart_id == scpart_map[n].part_id))
+				break;
+		if (n >= nr_scparts)
+			/* not match */
+			continue;
+
+		/* add the partition found in OF into MTD partition array */
+
+		/* reallocate partition array */
+		parts_tmp = parts;
+		parts = kzalloc((nr_parts + 1) * sizeof(*parts), GFP_KERNEL);
+		if (!parts) {
+			kfree(parts_tmp);
+			res = -ENOMEM;
+			goto free;
+		}
+		if (parts_tmp) {
+			memcpy(parts, parts_tmp, nr_parts * sizeof(*parts));
+			kfree(parts_tmp);
+		}
+
+		parts[nr_parts].offset = scpart_map[n].part_offs;
+		parts[nr_parts].size = scpart_map[n].part_bytes;
+		parts[nr_parts].of_node = pp;
+
+		if (!of_property_read_string(pp, "label", &partname) ||
+				!of_property_read_string(pp, "name", &partname))
+			parts[nr_parts].name = partname;
+
+		if (of_property_read_bool(pp, "read-only"))
+			parts[nr_parts].mask_flags |= MTD_WRITEABLE;
+		if (of_property_read_bool(pp, "lock"))
+			parts[nr_parts].mask_flags |= MTD_POWERUP_LOCK;
+
+		/* mark as 'done' */
+		scpart_map[n].part_id = ID_ALREADY_FOUND;
+
+		nr_parts++;
+	}
+	if (nr_parts > 0) {
+		*pparts = parts;
+		res = nr_parts;
+	} else
+		pr_info("%s: No partition in OF matches partition ID with 'SC PART MAP'.\n",
+				MOD_NAME);
+
+	of_node_put(pp);
+
+  free:
+	kfree(scpart_map);
+	if (res <= 0)
+		kfree(parts);
+
+  out:
+	return res;
+}
+
+static const struct of_device_id scpart_parser_of_match_table[] = {
+	{ .compatible = "sercomm,sc-partitions" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, scpart_parser_of_match_table);
+
+static struct mtd_part_parser scpart_parser = {
+	.parse_fn = scpart_parse,
+	.name = "scpart",
+	.of_match_table = scpart_parser_of_match_table,
+};
+module_mtd_part_parser(scpart_parser);
+
+/* mtd parsers will request the module by parser name */
+MODULE_ALIAS("scpart");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("NOGUCHI Hiroshi <drvlabo@gmail.com>");
+MODULE_DESCRIPTION("Parsing code for Sercomm/Netgear partition table");
diff --git a/target/linux/ramips/patches-5.4/303-mtd-scpart-parser.patch b/target/linux/ramips/patches-5.4/303-mtd-scpart-parser.patch
new file mode 100644
index 0000000000..f125d9c6af
--- /dev/null
+++ b/target/linux/ramips/patches-5.4/303-mtd-scpart-parser.patch
@@ -0,0 +1,19 @@ 
+--- a/drivers/mtd/parsers/Kconfig
++++ b/drivers/mtd/parsers/Kconfig
+@@ -185,3 +185,9 @@ config MTD_ROUTERBOOT_PARTS
+ 	 flash, some of which are fixed and some of which are located at
+ 	 variable offsets. This parser handles both cases via properly
+ 	 formatted DTS.
++
++config MTD_SERCOMM_PARTS
++	tristate "SERCOMM partitioning information support"
++	depends on MTD_OF_PARTS
++	help
++	  This provides partition table parser for SERCOMM partition map
+--- a/drivers/mtd/parsers/Makefile
++++ b/drivers/mtd/parsers/Makefile
+@@ -11,3 +11,4 @@ obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_
+ obj-$(CONFIG_MTD_SHARPSL_PARTS)		+= sharpslpart.o
+ obj-$(CONFIG_MTD_REDBOOT_PARTS)		+= redboot.o
+ obj-$(CONFIG_MTD_ROUTERBOOT_PARTS)		+= routerbootpart.o
++obj-$(CONFIG_MTD_SERCOMM_PARTS)		+= scpart.o