kernel/3.10: add separate rootfs partition parser

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38110 3c298f89-4303-0410-b956-a3cf2f4a3e73

4 files changed, 185 insertions, 0 deletions

diff --git a/target/linux/generic/config-3.10 b/target/linux/generic/config-3.10
index 9e1b10052a..61c7cf794b 100644
--- a/target/linux/generic/config-3.10
+++ b/target/linux/generic/config-3.10
@@ -1935,6 +1935,7 @@ CONFIG_MTD_ROOTFS_SPLIT=y
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_FIRMWARE is not set
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
+# CONFIG_MTD_SPLIT_SQUASHFS_ROOT is not set
 # CONFIG_MTD_SST25L is not set
 # CONFIG_MTD_SWAP is not set
 # CONFIG_MTD_TESTS is not set
diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit_squashfs.c b/target/linux/generic/files/drivers/mtd/mtdsplit_squashfs.c
new file mode 100644
index 0000000000..7953e8c382
--- /dev/null
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit_squashfs.c
@@ -0,0 +1,71 @@
+/*
+ *  Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
+ *  Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/magic.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/byteorder/generic.h>
+
+#include "mtdsplit.h"
+
+static int
+mtdsplit_parse_squashfs(struct mtd_info *master,
+			struct mtd_partition **pparts,
+			struct mtd_part_parser_data *data)
+{
+	struct mtd_partition *part;
+	struct mtd_info *parent_mtd;
+	size_t part_offset;
+	size_t squashfs_len;
+	int err;
+
+	err = mtd_get_squashfs_len(master, 0, &squashfs_len);
+	if (err)
+		return err;
+
+	parent_mtd = mtdpart_get_master(master);
+	part_offset = mtdpart_get_offset(master);
+
+	part = kzalloc(sizeof(*part), GFP_KERNEL);
+	if (!part) {
+		pr_alert("unable to allocate memory for \"%s\" partition\n",
+			 ROOTFS_SPLIT_NAME);
+		return -ENOMEM;
+	}
+
+	part->name = ROOTFS_SPLIT_NAME;
+	part->offset = mtd_roundup_to_eb(part_offset + squashfs_len,
+					 parent_mtd) - part_offset;
+	part->size = master->size - part->offset;
+
+	*pparts = part;
+	return 1;
+}
+
+static struct mtd_part_parser mtdsplit_squashfs_parser = {
+	.owner = THIS_MODULE,
+	.name = "squashfs-split",
+	.parse_fn = mtdsplit_parse_squashfs,
+	.type = MTD_PARSER_TYPE_ROOTFS,
+};
+
+static int
+mtdsplit_squashfs_init(void)
+{
+	return register_mtd_parser(&mtdsplit_squashfs_parser);
+}
+
+subsys_initcall(mtdsplit_squashfs_init);
diff --git a/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch b/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch
new file mode 100644
index 0000000000..4e54b1bf9d
--- /dev/null
+++ b/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch
@@ -0,0 +1,83 @@
+--- a/drivers/mtd/mtdpart.c
++++ b/drivers/mtd/mtdpart.c
+@@ -435,14 +435,12 @@ static struct mtd_part *allocate_partiti
+ 	if (slave->offset == MTDPART_OFS_APPEND)
+ 		slave->offset = cur_offset;
+ 	if (slave->offset == MTDPART_OFS_NXTBLK) {
+-		slave->offset = cur_offset;
+-		if (mtd_mod_by_eb(cur_offset, master) != 0) {
+-			/* Round up to next erasesize */
+-			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
++		/* Round up to next erasesize */
++		slave->offset = mtd_roundup_to_eb(cur_offset, master);
++		if (slave->offset != cur_offset)
+ 			printk(KERN_NOTICE "Moving partition %d: "
+ 			       "0x%012llx -> 0x%012llx\n", partno,
+ 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
+-		}
+ 	}
+ 	if (slave->offset == MTDPART_OFS_RETAIN) {
+ 		slave->offset = cur_offset;
+@@ -996,6 +994,24 @@ int mtd_is_partition(const struct mtd_in
+ }
+ EXPORT_SYMBOL_GPL(mtd_is_partition);
+ 
++struct mtd_info *mtdpart_get_master(const struct mtd_info *mtd)
++{
++	if (!mtd_is_partition(mtd))
++		return (struct mtd_info *)mtd;
++
++	return PART(mtd)->master;
++}
++EXPORT_SYMBOL_GPL(mtdpart_get_master);
++
++uint64_t mtdpart_get_offset(const struct mtd_info *mtd)
++{
++	if (!mtd_is_partition(mtd))
++		return 0;
++
++	return PART(mtd)->offset;
++}
++EXPORT_SYMBOL_GPL(mtdpart_get_offset);
++
+ /* Returns the size of the entire flash chip */
+ uint64_t mtd_get_device_size(const struct mtd_info *mtd)
+ {
+--- a/include/linux/mtd/partitions.h
++++ b/include/linux/mtd/partitions.h
+@@ -90,6 +90,8 @@ int mtd_is_partition(const struct mtd_in
+ int mtd_add_partition(struct mtd_info *master, char *name,
+ 		      long long offset, long long length);
+ int mtd_del_partition(struct mtd_info *master, int partno);
++struct mtd_info *mtdpart_get_master(const struct mtd_info *mtd);
++uint64_t mtdpart_get_offset(const struct mtd_info *mtd);
+ uint64_t mtd_get_device_size(const struct mtd_info *mtd);
+ extern void __weak arch_split_mtd_part(struct mtd_info *master,
+ 				       const char *name, int offset, int size);
+--- a/include/linux/mtd/mtd.h
++++ b/include/linux/mtd/mtd.h
+@@ -331,6 +331,24 @@ static inline uint32_t mtd_mod_by_eb(uin
+ 	return do_div(sz, mtd->erasesize);
+ }
+ 
++static inline uint64_t mtd_roundup_to_eb(uint64_t sz, struct mtd_info *mtd)
++{
++	if (mtd_mod_by_eb(sz, mtd) == 0)
++		return sz;
++
++	/* Round up to next erase block */
++	return (mtd_div_by_eb(sz, mtd) + 1) * mtd->erasesize;
++}
++
++static inline uint64_t mtd_rounddown_to_eb(uint64_t sz, struct mtd_info *mtd)
++{
++	if (mtd_mod_by_eb(sz, mtd) == 0)
++		return sz;
++
++	/* Round down to the start of the current erase block */
++	return (mtd_div_by_eb(sz, mtd)) * mtd->erasesize;
++}
++
+ static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
+ {
+ 	if (mtd->writesize_shift)
diff --git a/target/linux/generic/patches-3.10/406-mtd-add-squashfs-parser.patch b/target/linux/generic/patches-3.10/406-mtd-add-squashfs-parser.patch
new file mode 100644
index 0000000000..b3ff9d9ab2
--- /dev/null
+++ b/target/linux/generic/patches-3.10/406-mtd-add-squashfs-parser.patch
@@ -0,0 +1,30 @@
+--- a/drivers/mtd/Kconfig
++++ b/drivers/mtd/Kconfig
+@@ -37,6 +37,17 @@ config MTD_UIMAGE_SPLIT
+ 	depends on MTD_SPLIT_FIRMWARE
+ 	default y
+ 
++comment "Rootfs partition parsers"
++
++config MTD_SPLIT_SQUASHFS_ROOT
++	bool "Squashfs based root partition parser"
++	select MTD_SPLIT
++	default n
++	help
++	  This provides a parsing function which allows to detect the
++	  offset and size of the unused portion of a rootfs partition
++	  containing a squashfs.
++
+ config MTD_SPLIT
+ 	def_bool n
+ 	help 
+--- a/drivers/mtd/Makefile
++++ b/drivers/mtd/Makefile
+@@ -7,6 +7,7 @@ obj-$(CONFIG_MTD)		+= mtd.o
+ mtd-y				:= mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o
+ 
+ mtd-$(CONFIG_MTD_SPLIT)		+= mtdsplit.o
++mtd-$(CONFIG_MTD_SPLIT_SQUASHFS_ROOT) += mtdsplit_squashfs.o
+ 
+ obj-$(CONFIG_MTD_OF_PARTS)	+= ofpart.o
+ obj-$(CONFIG_MTD_REDBOOT_PARTS) += redboot.o