openwrt/target/linux/generic/pending-4.14/400-mtd-add-rootfs-split-support.patch
Rafał Miłecki 2a598bbaa3 kernel: backport mtd support for subpartitions in DT
This is a new & warm feature that allows nesting partiitons in DT and
mixing their types (e.g. static vs. dynamic). It's very useful for
boards that have most partitions static but some of them require extra
parsing (e.g. a "firmware" partition).

It's required to successfully backport support for new devices using
that new syntax in their DT files.

Since brcm63xx has a custom alternative patch the upstream one is being
reverted for it. The plan is to make brcm63xx use the upstream
implementation.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
2018-07-27 22:16:24 +02:00

125 lines
3.5 KiB
Diff

From: Felix Fietkau <nbd@nbd.name>
Subject: make rootfs split/detection more generic - patch can be moved to generic-2.6 after testing on other platforms
lede-commit: 328e660b31f0937d52c5ae3d6e7029409918a9df
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/mtd/Kconfig | 17 +++++++++++++++++
drivers/mtd/mtdpart.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/mtd/partitions.h | 2 ++
3 files changed, 54 insertions(+)
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -12,6 +12,23 @@ menuconfig MTD
if MTD
+menu "OpenWrt specific MTD options"
+
+config MTD_ROOTFS_ROOT_DEV
+ bool "Automatically set 'rootfs' partition to be root filesystem"
+ default y
+
+config MTD_SPLIT_FIRMWARE
+ bool "Automatically split firmware partition for kernel+rootfs"
+ default y
+
+config MTD_SPLIT_FIRMWARE_NAME
+ string "Firmware partition name"
+ depends on MTD_SPLIT_FIRMWARE
+ default "firmware"
+
+endmenu
+
config MTD_TESTS
tristate "MTD tests support (DANGEROUS)"
depends on m
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -29,11 +29,13 @@
#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
+#include <linux/magic.h>
#include <linux/of.h>
#include <linux/err.h>
#include <linux/of.h>
#include "mtdcore.h"
+#include "mtdsplit/mtdsplit.h"
/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
@@ -53,6 +55,8 @@ struct mtd_part {
struct list_head list;
};
+static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
+
/*
* Given a pointer to the MTD object in the mtd_part structure, we can retrieve
* the pointer to that structure.
@@ -658,6 +662,7 @@ int mtd_add_partition(struct mtd_info *p
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&new->mtd);
+ mtd_partition_split(parent, new);
mtd_add_partition_attrs(new);
@@ -736,6 +741,35 @@ int mtd_del_partition(struct mtd_info *m
}
EXPORT_SYMBOL_GPL(mtd_del_partition);
+#ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME
+#define SPLIT_FIRMWARE_NAME CONFIG_MTD_SPLIT_FIRMWARE_NAME
+#else
+#define SPLIT_FIRMWARE_NAME "unused"
+#endif
+
+static void split_firmware(struct mtd_info *master, struct mtd_part *part)
+{
+}
+
+void __weak arch_split_mtd_part(struct mtd_info *master, const char *name,
+ int offset, int size)
+{
+}
+
+static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
+{
+ static int rootfs_found = 0;
+
+ if (rootfs_found)
+ return;
+
+ if (!strcmp(part->mtd.name, SPLIT_FIRMWARE_NAME) &&
+ IS_ENABLED(CONFIG_MTD_SPLIT_FIRMWARE))
+ split_firmware(master, part);
+
+ arch_split_mtd_part(master, part->mtd.name, part->offset,
+ part->mtd.size);
+}
/*
* This function, given a master MTD object and a partition table, creates
* and registers slave MTD objects which are bound to the master according to
@@ -767,6 +801,7 @@ int add_mtd_partitions(struct mtd_info *
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&slave->mtd);
+ mtd_partition_split(master, slave);
mtd_add_partition_attrs(slave);
/* Look for subpartitions */
parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -110,5 +110,7 @@ int mtd_add_partition(struct mtd_info *m
long long offset, long long length);
int mtd_del_partition(struct mtd_info *master, int partno);
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);
#endif