target/linux/generic/patches-3.10/400-mtd-add-rootfs-split-support.patch

   1 --- a/drivers/mtd/Kconfig
   2 +++ b/drivers/mtd/Kconfig
   3 @@ -23,6 +23,23 @@ config MTD_TESTS
   4           WARNING: some of the tests will ERASE entire MTD device which they
   5           test. Do not use these tests unless you really know what you do.
   6
   7 +config MTD_ROOTFS_ROOT_DEV
   8 +       bool "Automatically set 'rootfs' partition to be root filesystem"
   9 +       default y
  10 +
  11 +config MTD_ROOTFS_SPLIT
  12 +       bool "Automatically split 'rootfs' partition for squashfs"
  13 +       default y
  14 +
  15 +config MTD_UIMAGE_SPLIT
  16 +       bool "Automatically split off rootfs from a kernel partition containing a uImage"
  17 +       default y
  18 +
  19 +config MTD_UIMAGE_SPLIT_NAME
  20 +       string "uImage partition name"
  21 +       depends on MTD_UIMAGE_SPLIT
  22 +       default "firmware"
  23 +
  24  config MTD_REDBOOT_PARTS
  25         tristate "RedBoot partition table parsing"
  26         ---help---
  27 --- a/drivers/mtd/mtdpart.c
  28 +++ b/drivers/mtd/mtdpart.c
  29 @@ -29,6 +29,8 @@
  30  #include <linux/kmod.h>
  31  #include <linux/mtd/mtd.h>
  32  #include <linux/mtd/partitions.h>
  33 +#include <linux/root_dev.h>
  34 +#include <linux/magic.h>
  35  #include <linux/err.h>
  36
  37  #include "mtdcore.h"
  38 @@ -45,13 +47,14 @@ struct mtd_part {
  39         struct list_head list;
  40  };
  41
  42 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
  43 +
  44  /*
  45   * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  46   * the pointer to that structure with this macro.
  47   */
  48  #define PART(x)  ((struct mtd_part *)(x))
  49
  50 -
  51  /*
  52   * MTD methods which simply translate the effective address and pass through
  53   * to the _real_ device.
  54 @@ -533,8 +536,10 @@ out_register:
  55         return slave;
  56  }
  57
  58 -int mtd_add_partition(struct mtd_info *master, char *name,
  59 -                     long long offset, long long length)
  60 +
  61 +static int
  62 +__mtd_add_partition(struct mtd_info *master, char *name,
  63 +                   long long offset, long long length, bool dup_check)
  64  {
  65         struct mtd_partition part;
  66         struct mtd_part *p, *new;
  67 @@ -566,21 +571,24 @@ int mtd_add_partition(struct mtd_info *m
  68         end = offset + length;
  69
  70         mutex_lock(&mtd_partitions_mutex);
  71 -       list_for_each_entry(p, &mtd_partitions, list)
  72 -               if (p->master == master) {
  73 -                       if ((start >= p->offset) &&
  74 -                           (start < (p->offset + p->mtd.size)))
  75 -                               goto err_inv;
  76 -
  77 -                       if ((end >= p->offset) &&
  78 -                           (end < (p->offset + p->mtd.size)))
  79 -                               goto err_inv;
  80 -               }
  81 +       if (dup_check) {
  82 +               list_for_each_entry(p, &mtd_partitions, list)
  83 +                       if (p->master == master) {
  84 +                               if ((start >= p->offset) &&
  85 +                                   (start < (p->offset + p->mtd.size)))
  86 +                                       goto err_inv;
  87 +
  88 +                               if ((end >= p->offset) &&
  89 +                                   (end < (p->offset + p->mtd.size)))
  90 +                                       goto err_inv;
  91 +                       }
  92 +       }
  93
  94         list_add(&new->list, &mtd_partitions);
  95         mutex_unlock(&mtd_partitions_mutex);
  96
  97         add_mtd_device(&new->mtd);
  98 +       mtd_partition_split(master, new);
  99
 100         return ret;
 101  err_inv:
 102 @@ -590,6 +598,12 @@ err_inv:
 103  }
 104  EXPORT_SYMBOL_GPL(mtd_add_partition);
 105
 106 +int mtd_add_partition(struct mtd_info *master, char *name,
 107 +                     long long offset, long long length)
 108 +{
 109 +       return __mtd_add_partition(master, name, offset, length, true);
 110 +}
 111 +
 112  int mtd_del_partition(struct mtd_info *master, int partno)
 113  {
 114         struct mtd_part *slave, *next;
 115 @@ -613,6 +627,148 @@ int mtd_del_partition(struct mtd_info *m
 116  }
 117  EXPORT_SYMBOL_GPL(mtd_del_partition);
 118
 119 +static inline unsigned long
 120 +mtd_pad_erasesize(struct mtd_info *mtd, int offset, int len)
 121 +{
 122 +       unsigned long mask = mtd->erasesize - 1;
 123 +
 124 +       len += offset & mask;
 125 +       len = (len + mask) & ~mask;
 126 +       len -= offset & mask;
 127 +       return len;
 128 +}
 129 +
 130 +#define ROOTFS_SPLIT_NAME "rootfs_data"
 131 +
 132 +struct squashfs_super_block {
 133 +       __le32 s_magic;
 134 +       __le32 pad0[9];
 135 +       __le64 bytes_used;
 136 +};
 137 +
 138 +
 139 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
 140 +{
 141 +       struct squashfs_super_block sb;
 142 +       int len, ret;
 143 +
 144 +       ret = mtd_read(master, offset, sizeof(sb), &len, (void *) &sb);
 145 +       if (ret || (len != sizeof(sb))) {
 146 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
 147 +                       "from \"%s\"\n", master->name);
 148 +               return -EINVAL;
 149 +       }
 150 +
 151 +       if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
 152 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
 153 +                       master->name);
 154 +               *split_offset = 0;
 155 +               return 0;
 156 +       }
 157 +
 158 +       if (le64_to_cpu((sb.bytes_used)) <= 0) {
 159 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
 160 +                       master->name);
 161 +               *split_offset = 0;
 162 +               return 0;
 163 +       }
 164 +
 165 +       len = (u32) le64_to_cpu(sb.bytes_used);
 166 +       len = mtd_pad_erasesize(master, offset, len);
 167 +       *split_offset = offset + len;
 168 +
 169 +       return 0;
 170 +}
 171 +
 172 +static void split_rootfs_data(struct mtd_info *master, struct mtd_part *part)
 173 +{
 174 +       unsigned int split_offset = 0;
 175 +       unsigned int split_size;
 176 +       int ret;
 177 +
 178 +       ret = split_squashfs(master, part->offset, &split_offset);
 179 +       if (ret)
 180 +               return;
 181 +
 182 +       if (split_offset <= 0)
 183 +               return;
 184 +
 185 +       split_size = part->mtd.size - (split_offset - part->offset);
 186 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=0x%x, len=0x%x\n",
 187 +               ROOTFS_SPLIT_NAME, split_offset, split_size);
 188 +
 189 +       __mtd_add_partition(master, ROOTFS_SPLIT_NAME, split_offset,
 190 +                           split_size, false);
 191 +}
 192 +
 193 +#define UBOOT_MAGIC    0x27051956
 194 +
 195 +#ifdef CONFIG_MTD_UIMAGE_SPLIT_NAME
 196 +#define UIMAGE_SPLIT_NAME      CONFIG_MTD_UIMAGE_SPLIT_NAME
 197 +#else
 198 +#define UIMAGE_SPLIT_NAME      "unused"
 199 +#endif
 200 +
 201 +static void split_uimage(struct mtd_info *master, struct mtd_part *part)
 202 +{
 203 +       struct {
 204 +               __be32 magic;
 205 +               __be32 pad[2];
 206 +               __be32 size;
 207 +       } hdr;
 208 +       size_t len;
 209 +
 210 +       if (strcmp(part->mtd.name, UIMAGE_SPLIT_NAME) != 0)
 211 +               return;
 212 +
 213 +       if (mtd_read(master, part->offset, sizeof(hdr), &len, (void *) &hdr))
 214 +               return;
 215 +
 216 +       if (len != sizeof(hdr) || hdr.magic != cpu_to_be32(UBOOT_MAGIC))
 217 +               return;
 218 +
 219 +       len = be32_to_cpu(hdr.size) + 0x40;
 220 +       len = mtd_pad_erasesize(master, part->offset, len);
 221 +       if (len + master->erasesize > part->mtd.size)
 222 +               return;
 223 +
 224 +       __mtd_add_partition(master, "rootfs", part->offset + len,
 225 +                           part->mtd.size - len, false);
 226 +}
 227 +
 228 +void __weak arch_split_mtd_part(struct mtd_info *master, const char *name,
 229 +                                int offset, int size)
 230 +{
 231 +}
 232 +
 233 +
 234 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
 235 +{
 236 +       static int rootfs_found = 0;
 237 +
 238 +       if (rootfs_found)
 239 +               return;
 240 +
 241 +       if (!strcmp(part->mtd.name, "rootfs")) {
 242 +               rootfs_found = 1;
 243 +
 244 +               if (config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
 245 +                   ROOT_DEV == 0) {
 246 +                       printk(KERN_NOTICE "mtd: partition \"rootfs\" "
 247 +                               "set to be root filesystem\n");
 248 +                       ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, part->mtd.index);
 249 +               }
 250 +
 251 +               if (config_enabled(CONFIG_MTD_ROOTFS_SPLIT))
 252 +                       split_rootfs_data(master, part);
 253 +       }
 254 +
 255 +       if (config_enabled(CONFIG_MTD_UIMAGE_SPLIT))
 256 +               split_uimage(master, part);
 257 +
 258 +       arch_split_mtd_part(master, part->mtd.name, part->offset,
 259 +                           part->mtd.size);
 260 +}
 261  /*
 262   * This function, given a master MTD object and a partition table, creates
 263   * and registers slave MTD objects which are bound to the master according to
 264 @@ -642,6 +798,7 @@ int add_mtd_partitions(struct mtd_info *
 265                 mutex_unlock(&mtd_partitions_mutex);
 266
 267                 add_mtd_device(&slave->mtd);
 268 +               mtd_partition_split(master, slave);
 269
 270                 cur_offset = slave->offset + slave->mtd.size;
 271         }
 272 --- a/include/linux/mtd/partitions.h
 273 +++ b/include/linux/mtd/partitions.h
 274 @@ -84,5 +84,7 @@ int mtd_add_partition(struct mtd_info *m
 275                       long long offset, long long length);
 276  int mtd_del_partition(struct mtd_info *master, int partno);
 277  uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 278 +extern void __weak arch_split_mtd_part(struct mtd_info *master,
 279 +                                      const char *name, int offset, int size);
 280
 281  #endif