openwrtv3/target/linux/generic/pending-4.14/404-mtd-add-more-helper-functions.patch
Rafał Miłecki 7e88753ace kernel: use add_mtd_partitions() helper when using OpenWrt parsers
This helper uses hierarchical partitions layout following the way
upstream parsers work. It's closer to what we should use when mainlining
our solutions. It also doesn't require hacky casting of struct
mtd_partition to the const.

THIS WILL AFFECT KERNEL PRINTING PARTITIONS IN THE LOG

Something like:
[    3.930158] 0x0000004e0000-0x000001fb0000 : "rootfs_data"
will get replaced by:
[    3.907338] Creating 1 MTD partitions on "rootfs":
[    3.912142] 0x00000031d400-0x000001ded400 : "rootfs_data"

It's important to understand that "rootfs_data" in above example is a
*subpartition* of the "rootfs" now. To get absolute addresses (e.g. for
some debugging purposes) one has to add them to the "rootfs", e.g.
[    3.912548] 0x0000001c2c00-0x000001fb0000 : "rootfs"

(0x1c2c00 + 0x31d400 = 0x4e0000)

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
2018-12-03 11:26:05 +01:00

76 lines
2.3 KiB
Diff

From: Gabor Juhos <juhosg@openwrt.org>
Subject: kernel/3.10: add separate rootfs partition parser
lede-commit: daec7ad7688415156e2730e401503d09bd3acf91
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
drivers/mtd/mtdpart.c | 29 +++++++++++++++++++++++++++++
include/linux/mtd/mtd.h | 18 ++++++++++++++++++
include/linux/mtd/partitions.h | 2 ++
3 files changed, 49 insertions(+)
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -1227,6 +1227,24 @@ 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 mtd_to_part(mtd)->parent;
+}
+EXPORT_SYMBOL_GPL(mtdpart_get_master);
+
+uint64_t mtdpart_get_offset(const struct mtd_info *mtd)
+{
+ if (!mtd_is_partition(mtd))
+ return 0;
+
+ return mtd_to_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/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -494,6 +494,24 @@ 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)
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -116,6 +116,8 @@ int mtd_is_partition(const struct mtd_in
int mtd_add_partition(struct mtd_info *master, const 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);
#endif