From 69357074558daf6ff24c9f58714935e9e095a865 Mon Sep 17 00:00:00 2001
From: OpenWrt community <openwrt-devel@lists.openwrt.org>
Date: Wed, 13 Jul 2022 13:37:33 +0200
Subject: [PATCH] kernel: add block fit partition parser

---
 block/blk.h                     |  2 ++
 block/partitions/Kconfig        |  7 +++++++
 block/partitions/Makefile       |  1 +
 block/partitions/check.h        |  3 +++
 block/partitions/core.c         | 17 +++++++++++++++++
 block/partitions/efi.c          |  8 ++++++++
 block/partitions/efi.h          |  3 +++
 block/partitions/msdos.c        | 10 ++++++++++
 drivers/mtd/mtd_blkdevs.c       |  2 ++
 drivers/mtd/ubi/block.c         |  3 +++
 include/linux/msdos_partition.h |  1 +
 11 files changed, 57 insertions(+)

--- a/block/blk.h
+++ b/block/blk.h
@@ -423,6 +423,8 @@ void blk_free_ext_minor(unsigned int min
 #define ADDPART_FLAG_NONE	0
 #define ADDPART_FLAG_RAID	1
 #define ADDPART_FLAG_WHOLEDISK	2
+#define ADDPART_FLAG_READONLY	4
+#define ADDPART_FLAG_ROOTDEV	8
 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
 		sector_t length);
 int bdev_del_partition(struct gendisk *disk, int partno);
--- a/block/partitions/Kconfig
+++ b/block/partitions/Kconfig
@@ -103,6 +103,13 @@ config ATARI_PARTITION
 	  Say Y here if you would like to use hard disks under Linux which
 	  were partitioned under the Atari OS.
 
+config FIT_PARTITION
+	bool "Flattened-Image-Tree (FIT) partition support" if PARTITION_ADVANCED
+	default n
+	help
+	  Say Y here if your system needs to mount the filesystem part of
+	  a Flattened-Image-Tree (FIT) image commonly used with Das U-Boot.
+
 config IBM_PARTITION
 	bool "IBM disk label and partition support"
 	depends on PARTITION_ADVANCED && S390
--- a/block/partitions/Makefile
+++ b/block/partitions/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_ACORN_PARTITION) += acorn.o
 obj-$(CONFIG_AMIGA_PARTITION) += amiga.o
 obj-$(CONFIG_ATARI_PARTITION) += atari.o
 obj-$(CONFIG_AIX_PARTITION) += aix.o
+obj-$(CONFIG_FIT_PARTITION) += fit.o
 obj-$(CONFIG_CMDLINE_PARTITION) += cmdline.o
 obj-$(CONFIG_MAC_PARTITION) += mac.o
 obj-$(CONFIG_LDM_PARTITION) += ldm.o
--- a/block/partitions/check.h
+++ b/block/partitions/check.h
@@ -57,6 +57,7 @@ int amiga_partition(struct parsed_partit
 int atari_partition(struct parsed_partitions *state);
 int cmdline_partition(struct parsed_partitions *state);
 int efi_partition(struct parsed_partitions *state);
+int fit_partition(struct parsed_partitions *state);
 int ibm_partition(struct parsed_partitions *);
 int karma_partition(struct parsed_partitions *state);
 int ldm_partition(struct parsed_partitions *state);
@@ -67,3 +68,5 @@ int sgi_partition(struct parsed_partitio
 int sun_partition(struct parsed_partitions *state);
 int sysv68_partition(struct parsed_partitions *state);
 int ultrix_partition(struct parsed_partitions *state);
+
+int parse_fit_partitions(struct parsed_partitions *state, u64 start_sector, u64 nr_sectors, int *slot, int add_remain);
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -11,6 +11,9 @@
 #include <linux/vmalloc.h>
 #include <linux/raid/detect.h>
 #include <linux/property.h>
+#ifdef CONFIG_FIT_PARTITION
+#include <linux/root_dev.h>
+#endif
 
 #include "check.h"
 
@@ -48,6 +51,9 @@ static int (*const check_part[])(struct
 #ifdef CONFIG_EFI_PARTITION
 	efi_partition,		/* this must come before msdos */
 #endif
+#ifdef CONFIG_FIT_PARTITION
+	fit_partition,
+#endif
 #ifdef CONFIG_SGI_PARTITION
 	sgi_partition,
 #endif
@@ -433,6 +439,11 @@ static struct block_device *add_partitio
 			goto out_del;
 	}
 
+#ifdef CONFIG_FIT_PARTITION
+	if (flags & ADDPART_FLAG_READONLY)
+		bdev->bd_read_only = true;
+#endif
+
 	/* everything is up and running, commence */
 	err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
 	if (err)
@@ -625,6 +636,11 @@ static bool blk_add_partition(struct gen
 	    (state->parts[p].flags & ADDPART_FLAG_RAID))
 		md_autodetect_dev(part->bd_dev);
 
+#ifdef CONFIG_FIT_PARTITION
+	if ((state->parts[p].flags & ADDPART_FLAG_ROOTDEV) && ROOT_DEV == 0)
+		ROOT_DEV = part->bd_dev;
+#endif
+
 	return true;
 }
 
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -716,6 +716,9 @@ int efi_partition(struct parsed_partitio
 	gpt_entry *ptes = NULL;
 	u32 i;
 	unsigned ssz = queue_logical_block_size(state->disk->queue) / 512;
+#ifdef CONFIG_FIT_PARTITION
+	u32 extra_slot = 64;
+#endif
 
 	if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
 		kfree(gpt);
@@ -749,6 +752,11 @@ int efi_partition(struct parsed_partitio
 				ARRAY_SIZE(ptes[i].partition_name));
 		utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname);
 		state->parts[i + 1].has_info = true;
+#ifdef CONFIG_FIT_PARTITION
+		/* If this is a U-Boot FIT volume it may have subpartitions */
+		if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_FIT_GUID))
+			(void) parse_fit_partitions(state, start * ssz, size * ssz, &extra_slot, 1);
+#endif
 	}
 	kfree(ptes);
 	kfree(gpt);
--- a/block/partitions/efi.h
+++ b/block/partitions/efi.h
@@ -51,6 +51,9 @@
 #define PARTITION_LINUX_LVM_GUID \
     EFI_GUID( 0xe6d6d379, 0xf507, 0x44c2, \
               0xa2, 0x3c, 0x23, 0x8f, 0x2a, 0x3d, 0xf9, 0x28)
+#define PARTITION_LINUX_FIT_GUID \
+    EFI_GUID( 0xcae9be83, 0xb15f, 0x49cc, \
+              0x86, 0x3f, 0x08, 0x1b, 0x74, 0x4a, 0x2d, 0x93)
 
 typedef struct _gpt_header {
 	__le64 signature;
--- a/block/partitions/msdos.c
+++ b/block/partitions/msdos.c
@@ -564,6 +564,15 @@ static void parse_minix(struct parsed_pa
 #endif /* CONFIG_MINIX_SUBPARTITION */
 }
 
+static void parse_fit_mbr(struct parsed_partitions *state,
+			  sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_FIT_PARTITION
+	u32 extra_slot = 64;
+	(void) parse_fit_partitions(state, offset, size, &extra_slot, 1);
+#endif /* CONFIG_FIT_PARTITION */
+}
+
 static struct {
 	unsigned char id;
 	void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
@@ -575,6 +584,7 @@ static struct {
 	{UNIXWARE_PARTITION, parse_unixware},
 	{SOLARIS_X86_PARTITION, parse_solaris_x86},
 	{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
+	{FIT_PARTITION, parse_fit_mbr},
 	{0, NULL},
 };
 
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -359,7 +359,9 @@ int add_mtd_blktrans_dev(struct mtd_blkt
 	} else {
 		snprintf(gd->disk_name, sizeof(gd->disk_name),
 			 "%s%d", tr->name, new->devnum);
-		gd->flags |= GENHD_FL_NO_PART;
+
+		if (!IS_ENABLED(CONFIG_FIT_PARTITION) || mtd_type_is_nand(new->mtd))
+			gd->flags |= GENHD_FL_NO_PART;
 	}
 
 	set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -411,7 +411,9 @@ int ubiblock_create(struct ubi_volume_in
 		ret = -ENODEV;
 		goto out_cleanup_disk;
 	}
-	gd->flags |= GENHD_FL_NO_PART;
+	if (!IS_ENABLED(CONFIG_FIT_PARTITION))
+		gd->flags |= GENHD_FL_NO_PART;
+
 	gd->private_data = dev;
 	sprintf(gd->disk_name, "ubiblock%d_%d", dev->ubi_num, dev->vol_id);
 	set_capacity(gd, disk_capacity);
--- a/include/linux/msdos_partition.h
+++ b/include/linux/msdos_partition.h
@@ -31,6 +31,7 @@ enum msdos_sys_ind {
 	LINUX_LVM_PARTITION = 0x8e,
 	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
 
+	FIT_PARTITION = 0x2e,		/* U-Boot uImage.FIT */
 	SOLARIS_X86_PARTITION =	0x82,	/* also Linux swap partitions */
 	NEW_SOLARIS_X86_PARTITION = 0xbf,
 
