kernel: rewrite run_parsers_by_type() to use add_mtd_partitions()

Make run_parsers_by_type() more similar to the parse_mtd_partitions():
1. Use struct mtd_partitions
2. Use add_mtd_partitions()

This change simplifies run_parsers_by_type() by:
1. Dropping loop
2. Dropping code getting partition properties (name, offset, size)

Moreover this change allows passing more partitions details (e.g.
mask_flags).

One noticeable change introduced by this patch is adding parsed
partitions as children. This results in printing their *relative*
offsets which unifies this code with parse_mtd_partitions() behaviour.

Before:
[    1.785448] 0x00000018f800-0x000000fb0000 : "rootfs"
[    1.791642] mtd: device 4 (rootfs) set to be root filesystem
[    1.797537] 1 squashfs-split partitions found on MTD device rootfs
[    1.804009] 0x0000004e0000-0x000000fb0000 : "rootfs_data"

After:
[    1.785376] 0x00000018f800-0x000000fb0000 : "rootfs"
[    1.791601] mtd: device 4 (rootfs) set to be root filesystem
[    1.797491] 1 squashfs-split partitions found on MTD device rootfs
[    1.803936] Creating 1 MTD partitions on "rootfs":
[    1.808910] 0x000000350800-0x000000e20800 : "rootfs_data"

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

target/linux/generic/pending-4.14/401-mtd-add-support-for-different-partition-parser-types.patch

@@ -20,44 +20,35 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  
  /*
   * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
-@@ -762,6 +766,36 @@ int mtd_del_partition(struct mtd_info *m
+@@ -762,6 +766,27 @@ int mtd_del_partition(struct mtd_info *m
  }
  EXPORT_SYMBOL_GPL(mtd_del_partition);
  
 +static int
 +run_parsers_by_type(struct mtd_part *slave, enum mtd_parser_type type)
 +{
-+	struct mtd_partition *parts;
-+	int nr_parts;
-+	int i;
++	struct mtd_partitions pparts = { };
++	int err;
 +
-+	nr_parts = parse_mtd_partitions_by_type(&slave->mtd, type, (const struct mtd_partition **)&parts,
-+						NULL);
-+	if (nr_parts <= 0)
-+		return nr_parts;
++	pparts.nr_parts = parse_mtd_partitions_by_type(&slave->mtd, type,
++						       &pparts.parts, NULL);
++	if (pparts.nr_parts <= 0)
++		return pparts.nr_parts;
 +
-+	if (WARN_ON(!parts))
++	if (WARN_ON(!pparts.parts))
 +		return 0;
 +
-+	for (i = 0; i < nr_parts; i++) {
-+		/* adjust partition offsets */
-+		parts[i].offset += slave->offset;
++	err = add_mtd_partitions(&slave->mtd, pparts.parts, pparts.nr_parts);
 +
-+		mtd_add_partition(slave->parent,
-+				  parts[i].name,
-+				  parts[i].offset,
-+				  parts[i].size);
-+	}
++	kfree(pparts.parts);
 +
-+	kfree(parts);
-+
-+	return nr_parts;
++	return err ? err : pparts.nr_parts;
 +}
 +
  #ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME
  #define SPLIT_FIRMWARE_NAME	CONFIG_MTD_SPLIT_FIRMWARE_NAME
  #else
-@@ -1147,6 +1181,61 @@ void mtd_part_parser_cleanup(struct mtd_
+@@ -1147,6 +1172,61 @@ void mtd_part_parser_cleanup(struct mtd_
  	}
  }
  

target/linux/generic/pending-4.14/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch

@@ -10,7 +10,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
 
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -804,6 +804,7 @@ run_parsers_by_type(struct mtd_part *sla
+@@ -795,6 +795,7 @@ run_parsers_by_type(struct mtd_part *sla
  
  static void split_firmware(struct mtd_info *master, struct mtd_part *part)
  {
@@ -18,7 +18,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  }
  
  static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
-@@ -813,6 +814,12 @@ static void mtd_partition_split(struct m
+@@ -804,6 +805,12 @@ static void mtd_partition_split(struct m
  	if (rootfs_found)
  		return;
  

target/linux/generic/pending-4.14/404-mtd-add-more-helper-functions.patch

@@ -11,7 +11,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
 
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -1260,6 +1260,24 @@ int mtd_is_partition(const struct mtd_in
+@@ -1251,6 +1251,24 @@ int mtd_is_partition(const struct mtd_in
  }
  EXPORT_SYMBOL_GPL(mtd_is_partition);