target/linux/generic/pending-4.9/400-mtd-add-rootfs-split-support.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: make rootfs split/detection more generic - patch can be moved to generic-2.6 after testing on other platforms
   3
   4 lede-commit: 328e660b31f0937d52c5ae3d6e7029409918a9df
   5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   6 ---
   7  drivers/mtd/Kconfig            | 17 +++++++++++++++++
   8  drivers/mtd/mtdpart.c          | 35 +++++++++++++++++++++++++++++++++++
   9  include/linux/mtd/partitions.h |  2 ++
  10  3 files changed, 54 insertions(+)
  11
  12 --- a/drivers/mtd/Kconfig
  13 +++ b/drivers/mtd/Kconfig
  14 @@ -12,6 +12,23 @@ menuconfig MTD
  15
  16  if MTD
  17
  18 +menu "OpenWrt specific MTD options"
  19 +
  20 +config MTD_ROOTFS_ROOT_DEV
  21 +       bool "Automatically set 'rootfs' partition to be root filesystem"
  22 +       default y
  23 +
  24 +config MTD_SPLIT_FIRMWARE
  25 +       bool "Automatically split firmware partition for kernel+rootfs"
  26 +       default y
  27 +
  28 +config MTD_SPLIT_FIRMWARE_NAME
  29 +       string "Firmware partition name"
  30 +       depends on MTD_SPLIT_FIRMWARE
  31 +       default "firmware"
  32 +
  33 +endmenu
  34 +
  35  config MTD_TESTS
  36         tristate "MTD tests support (DANGEROUS)"
  37         depends on m
  38 --- a/drivers/mtd/mtdpart.c
  39 +++ b/drivers/mtd/mtdpart.c
  40 @@ -29,11 +29,13 @@
  41  #include <linux/kmod.h>
  42  #include <linux/mtd/mtd.h>
  43  #include <linux/mtd/partitions.h>
  44 +#include <linux/magic.h>
  45  #include <linux/of.h>
  46  #include <linux/err.h>
  47  #include <linux/of.h>
  48
  49  #include "mtdcore.h"
  50 +#include "mtdsplit/mtdsplit.h"
  51
  52  /* Our partition linked list */
  53  static LIST_HEAD(mtd_partitions);
  54 @@ -53,6 +55,8 @@ struct mtd_part {
  55         struct list_head list;
  56  };
  57
  58 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
  59 +
  60  /*
  61   * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  62   * the pointer to that structure.
  63 @@ -650,6 +654,7 @@ int mtd_add_partition(struct mtd_info *p
  64         mutex_unlock(&mtd_partitions_mutex);
  65
  66         add_mtd_device(&new->mtd);
  67 +       mtd_partition_split(parent, new);
  68
  69         mtd_add_partition_attrs(new);
  70
  71 @@ -728,6 +733,29 @@ int mtd_del_partition(struct mtd_info *m
  72  }
  73  EXPORT_SYMBOL_GPL(mtd_del_partition);
  74
  75 +#ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME
  76 +#define SPLIT_FIRMWARE_NAME    CONFIG_MTD_SPLIT_FIRMWARE_NAME
  77 +#else
  78 +#define SPLIT_FIRMWARE_NAME    "unused"
  79 +#endif
  80 +
  81 +static void split_firmware(struct mtd_info *master, struct mtd_part *part)
  82 +{
  83 +}
  84 +
  85 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
  86 +{
  87 +       static int rootfs_found = 0;
  88 +
  89 +       if (rootfs_found)
  90 +               return;
  91 +
  92 +       if (IS_ENABLED(CONFIG_MTD_SPLIT_FIRMWARE) &&
  93 +           !strcmp(part->mtd.name, SPLIT_FIRMWARE_NAME) &&
  94 +           !of_find_property(mtd_get_of_node(&part->mtd), "compatible", NULL))
  95 +               split_firmware(master, part);
  96 +}
  97 +
  98  /*
  99   * This function, given a master MTD object and a partition table, creates
 100   * and registers slave MTD objects which are bound to the master according to
 101 @@ -759,6 +787,7 @@ int add_mtd_partitions(struct mtd_info *
 102                 mutex_unlock(&mtd_partitions_mutex);
 103
 104                 add_mtd_device(&slave->mtd);
 105 +               mtd_partition_split(master, slave);
 106                 mtd_add_partition_attrs(slave);
 107                 /* Look for subpartitions */
 108                 parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);