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 diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
  13 index 5a2d71729b9a..f5ac04e288eb 100644
  14 --- a/drivers/mtd/Kconfig
  15 +++ b/drivers/mtd/Kconfig
  16 @@ -12,6 +12,23 @@ menuconfig MTD
  17
  18  if MTD
  19
  20 +menu "OpenWrt specific MTD options"
  21 +
  22 +config MTD_ROOTFS_ROOT_DEV
  23 +       bool "Automatically set 'rootfs' partition to be root filesystem"
  24 +       default y
  25 +
  26 +config MTD_SPLIT_FIRMWARE
  27 +       bool "Automatically split firmware partition for kernel+rootfs"
  28 +       default y
  29 +
  30 +config MTD_SPLIT_FIRMWARE_NAME
  31 +       string "Firmware partition name"
  32 +       depends on MTD_SPLIT_FIRMWARE
  33 +       default "firmware"
  34 +
  35 +endmenu
  36 +
  37  config MTD_TESTS
  38         tristate "MTD tests support (DANGEROUS)"
  39         depends on m
  40 diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
  41 index dd86b430e46e..33d152d1876a 100644
  42 --- a/drivers/mtd/mtdpart.c
  43 +++ b/drivers/mtd/mtdpart.c
  44 @@ -29,10 +29,12 @@
  45  #include <linux/kmod.h>
  46  #include <linux/mtd/mtd.h>
  47  #include <linux/mtd/partitions.h>
  48 +#include <linux/magic.h>
  49  #include <linux/of.h>
  50  #include <linux/err.h>
  51
  52  #include "mtdcore.h"
  53 +#include "mtdsplit/mtdsplit.h"
  54
  55  /* Our partition linked list */
  56  static LIST_HEAD(mtd_partitions);
  57 @@ -52,6 +54,8 @@ struct mtd_part {
  58         struct list_head list;
  59  };
  60
  61 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
  62 +
  63  /*
  64   * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  65   * the pointer to that structure.
  66 @@ -678,6 +682,7 @@ int mtd_add_partition(struct mtd_info *parent, const char *name,
  67         mutex_unlock(&mtd_partitions_mutex);
  68
  69         add_mtd_device(&new->mtd);
  70 +       mtd_partition_split(parent, new);
  71
  72         mtd_add_partition_attrs(new);
  73
  74 @@ -756,6 +761,35 @@ int mtd_del_partition(struct mtd_info *mtd, int partno)
  75  }
  76  EXPORT_SYMBOL_GPL(mtd_del_partition);
  77
  78 +#ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME
  79 +#define SPLIT_FIRMWARE_NAME    CONFIG_MTD_SPLIT_FIRMWARE_NAME
  80 +#else
  81 +#define SPLIT_FIRMWARE_NAME    "unused"
  82 +#endif
  83 +
  84 +static void split_firmware(struct mtd_info *master, struct mtd_part *part)
  85 +{
  86 +}
  87 +
  88 +void __weak arch_split_mtd_part(struct mtd_info *master, const char *name,
  89 +                                int offset, int size)
  90 +{
  91 +}
  92 +
  93 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
  94 +{
  95 +       static int rootfs_found = 0;
  96 +
  97 +       if (rootfs_found)
  98 +               return;
  99 +
 100 +       if (!strcmp(part->mtd.name, SPLIT_FIRMWARE_NAME) &&
 101 +           IS_ENABLED(CONFIG_MTD_SPLIT_FIRMWARE))
 102 +               split_firmware(master, part);
 103 +
 104 +       arch_split_mtd_part(master, part->mtd.name, part->offset,
 105 +                           part->mtd.size);
 106 +}
 107  /*
 108   * This function, given a master MTD object and a partition table, creates
 109   * and registers slave MTD objects which are bound to the master according to
 110 @@ -787,6 +821,7 @@ int add_mtd_partitions(struct mtd_info *master,
 111                 mutex_unlock(&mtd_partitions_mutex);
 112
 113                 add_mtd_device(&slave->mtd);
 114 +               mtd_partition_split(master, slave);
 115                 mtd_add_partition_attrs(slave);
 116                 if (parts[i].types)
 117                         mtd_parse_part(slave, parts[i].types);
 118 diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
 119 index c4beb70dacbd..320a791290c5 100644
 120 --- a/include/linux/mtd/partitions.h
 121 +++ b/include/linux/mtd/partitions.h
 122 @@ -109,5 +109,7 @@ int mtd_add_partition(struct mtd_info *master, const char *name,
 123                       long long offset, long long length);
 124  int mtd_del_partition(struct mtd_info *master, int partno);
 125  uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 126 +extern void __weak arch_split_mtd_part(struct mtd_info *master,
 127 +                                      const char *name, int offset, int size);
 128
 129  #endif
 130 --
 131 2.11.0
 132