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

   1 --- a/drivers/mtd/Kconfig
   2 +++ b/drivers/mtd/Kconfig
   3 @@ -12,6 +12,27 @@ menuconfig MTD
   4
   5  if MTD
   6
   7 +menu "OpenWrt specific MTD options"
   8 +
   9 +config MTD_ROOTFS_ROOT_DEV
  10 +       bool "Automatically set 'rootfs' partition to be root filesystem"
  11 +       default y
  12 +
  13 +config MTD_ROOTFS_SPLIT
  14 +       bool "Automatically split 'rootfs' partition for squashfs"
  15 +       default y
  16 +
  17 +config MTD_UIMAGE_SPLIT
  18 +       bool "Automatically split off rootfs from a kernel partition containing a uImage"
  19 +       default y
  20 +
  21 +config MTD_UIMAGE_SPLIT_NAME
  22 +       string "uImage partition name"
  23 +       depends on MTD_UIMAGE_SPLIT
  24 +       default "firmware"
  25 +
  26 +endmenu
  27 +
  28  config MTD_TESTS
  29         tristate "MTD tests support (DANGEROUS)"
  30         depends on m
  31 --- a/drivers/mtd/mtdpart.c
  32 +++ b/drivers/mtd/mtdpart.c
  33 @@ -29,6 +29,8 @@
  34  #include <linux/kmod.h>
  35  #include <linux/mtd/mtd.h>
  36  #include <linux/mtd/partitions.h>
  37 +#include <linux/root_dev.h>
  38 +#include <linux/magic.h>
  39  #include <linux/err.h>
  40
  41  #include "mtdcore.h"
  42 @@ -45,13 +47,14 @@ struct mtd_part {
  43         struct list_head list;
  44  };
  45
  46 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part);
  47 +
  48  /*
  49   * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  50   * the pointer to that structure with this macro.
  51   */
  52  #define PART(x)  ((struct mtd_part *)(x))
  53
  54 -
  55  /*
  56   * MTD methods which simply translate the effective address and pass through
  57   * to the _real_ device.
  58 @@ -533,8 +536,10 @@ out_register:
  59         return slave;
  60  }
  61
  62 -int mtd_add_partition(struct mtd_info *master, char *name,
  63 -                     long long offset, long long length)
  64 +
  65 +static int
  66 +__mtd_add_partition(struct mtd_info *master, char *name,
  67 +                   long long offset, long long length, bool dup_check)
  68  {
  69         struct mtd_partition part;
  70         struct mtd_part *p, *new;
  71 @@ -566,21 +571,24 @@ int mtd_add_partition(struct mtd_info *m
  72         end = offset + length;
  73
  74         mutex_lock(&mtd_partitions_mutex);
  75 -       list_for_each_entry(p, &mtd_partitions, list)
  76 -               if (p->master == master) {
  77 -                       if ((start >= p->offset) &&
  78 -                           (start < (p->offset + p->mtd.size)))
  79 -                               goto err_inv;
  80 -
  81 -                       if ((end >= p->offset) &&
  82 -                           (end < (p->offset + p->mtd.size)))
  83 -                               goto err_inv;
  84 -               }
  85 +       if (dup_check) {
  86 +               list_for_each_entry(p, &mtd_partitions, list)
  87 +                       if (p->master == master) {
  88 +                               if ((start >= p->offset) &&
  89 +                                   (start < (p->offset + p->mtd.size)))
  90 +                                       goto err_inv;
  91 +
  92 +                               if ((end >= p->offset) &&
  93 +                                   (end < (p->offset + p->mtd.size)))
  94 +                                       goto err_inv;
  95 +                       }
  96 +       }
  97
  98         list_add(&new->list, &mtd_partitions);
  99         mutex_unlock(&mtd_partitions_mutex);
 100
 101         add_mtd_device(&new->mtd);
 102 +       mtd_partition_split(master, new);
 103
 104         return ret;
 105  err_inv:
 106 @@ -590,6 +598,12 @@ err_inv:
 107  }
 108  EXPORT_SYMBOL_GPL(mtd_add_partition);
 109
 110 +int mtd_add_partition(struct mtd_info *master, char *name,
 111 +                     long long offset, long long length)
 112 +{
 113 +       return __mtd_add_partition(master, name, offset, length, true);
 114 +}
 115 +
 116  int mtd_del_partition(struct mtd_info *master, int partno)
 117  {
 118         struct mtd_part *slave, *next;
 119 @@ -613,6 +627,148 @@ int mtd_del_partition(struct mtd_info *m
 120  }
 121  EXPORT_SYMBOL_GPL(mtd_del_partition);
 122
 123 +static inline unsigned long
 124 +mtd_pad_erasesize(struct mtd_info *mtd, int offset, int len)
 125 +{
 126 +       unsigned long mask = mtd->erasesize - 1;
 127 +
 128 +       len += offset & mask;
 129 +       len = (len + mask) & ~mask;
 130 +       len -= offset & mask;
 131 +       return len;
 132 +}
 133 +
 134 +#define ROOTFS_SPLIT_NAME "rootfs_data"
 135 +
 136 +struct squashfs_super_block {
 137 +       __le32 s_magic;
 138 +       __le32 pad0[9];
 139 +       __le64 bytes_used;
 140 +};
 141 +
 142 +
 143 +static int split_squashfs(struct mtd_info *master, int offset, int *split_offset)
 144 +{
 145 +       struct squashfs_super_block sb;
 146 +       int len, ret;
 147 +
 148 +       ret = mtd_read(master, offset, sizeof(sb), &len, (void *) &sb);
 149 +       if (ret || (len != sizeof(sb))) {
 150 +               printk(KERN_ALERT "split_squashfs: error occured while reading "
 151 +                       "from \"%s\"\n", master->name);
 152 +               return -EINVAL;
 153 +       }
 154 +
 155 +       if (SQUASHFS_MAGIC != le32_to_cpu(sb.s_magic) ) {
 156 +               printk(KERN_ALERT "split_squashfs: no squashfs found in \"%s\"\n",
 157 +                       master->name);
 158 +               *split_offset = 0;
 159 +               return 0;
 160 +       }
 161 +
 162 +       if (le64_to_cpu((sb.bytes_used)) <= 0) {
 163 +               printk(KERN_ALERT "split_squashfs: squashfs is empty in \"%s\"\n",
 164 +                       master->name);
 165 +               *split_offset = 0;
 166 +               return 0;
 167 +       }
 168 +
 169 +       len = (u32) le64_to_cpu(sb.bytes_used);
 170 +       len = mtd_pad_erasesize(master, offset, len);
 171 +       *split_offset = offset + len;
 172 +
 173 +       return 0;
 174 +}
 175 +
 176 +static void split_rootfs_data(struct mtd_info *master, struct mtd_part *part)
 177 +{
 178 +       unsigned int split_offset = 0;
 179 +       unsigned int split_size;
 180 +       int ret;
 181 +
 182 +       ret = split_squashfs(master, part->offset, &split_offset);
 183 +       if (ret)
 184 +               return;
 185 +
 186 +       if (split_offset <= 0)
 187 +               return;
 188 +
 189 +       split_size = part->mtd.size - (split_offset - part->offset);
 190 +       printk(KERN_INFO "mtd: partition \"%s\" created automatically, ofs=0x%x, len=0x%x\n",
 191 +               ROOTFS_SPLIT_NAME, split_offset, split_size);
 192 +
 193 +       __mtd_add_partition(master, ROOTFS_SPLIT_NAME, split_offset,
 194 +                           split_size, false);
 195 +}
 196 +
 197 +#define UBOOT_MAGIC    0x27051956
 198 +
 199 +#ifdef CONFIG_MTD_UIMAGE_SPLIT_NAME
 200 +#define UIMAGE_SPLIT_NAME      CONFIG_MTD_UIMAGE_SPLIT_NAME
 201 +#else
 202 +#define UIMAGE_SPLIT_NAME      "unused"
 203 +#endif
 204 +
 205 +static void split_uimage(struct mtd_info *master, struct mtd_part *part)
 206 +{
 207 +       struct {
 208 +               __be32 magic;
 209 +               __be32 pad[2];
 210 +               __be32 size;
 211 +       } hdr;
 212 +       size_t len;
 213 +
 214 +       if (strcmp(part->mtd.name, UIMAGE_SPLIT_NAME) != 0)
 215 +               return;
 216 +
 217 +       if (mtd_read(master, part->offset, sizeof(hdr), &len, (void *) &hdr))
 218 +               return;
 219 +
 220 +       if (len != sizeof(hdr) || hdr.magic != cpu_to_be32(UBOOT_MAGIC))
 221 +               return;
 222 +
 223 +       len = be32_to_cpu(hdr.size) + 0x40;
 224 +       len = mtd_pad_erasesize(master, part->offset, len);
 225 +       if (len + master->erasesize > part->mtd.size)
 226 +               return;
 227 +
 228 +       __mtd_add_partition(master, "rootfs", part->offset + len,
 229 +                           part->mtd.size - len, false);
 230 +}
 231 +
 232 +void __weak arch_split_mtd_part(struct mtd_info *master, const char *name,
 233 +                                int offset, int size)
 234 +{
 235 +}
 236 +
 237 +
 238 +static void mtd_partition_split(struct mtd_info *master, struct mtd_part *part)
 239 +{
 240 +       static int rootfs_found = 0;
 241 +
 242 +       if (rootfs_found)
 243 +               return;
 244 +
 245 +       if (!strcmp(part->mtd.name, "rootfs")) {
 246 +               rootfs_found = 1;
 247 +
 248 +               if (config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
 249 +                   ROOT_DEV == 0) {
 250 +                       printk(KERN_NOTICE "mtd: partition \"rootfs\" "
 251 +                               "set to be root filesystem\n");
 252 +                       ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, part->mtd.index);
 253 +               }
 254 +
 255 +               if (config_enabled(CONFIG_MTD_ROOTFS_SPLIT))
 256 +                       split_rootfs_data(master, part);
 257 +       }
 258 +
 259 +       if (config_enabled(CONFIG_MTD_UIMAGE_SPLIT))
 260 +               split_uimage(master, part);
 261 +
 262 +       arch_split_mtd_part(master, part->mtd.name, part->offset,
 263 +                           part->mtd.size);
 264 +}
 265  /*
 266   * This function, given a master MTD object and a partition table, creates
 267   * and registers slave MTD objects which are bound to the master according to
 268 @@ -642,6 +798,7 @@ int add_mtd_partitions(struct mtd_info *
 269                 mutex_unlock(&mtd_partitions_mutex);
 270
 271                 add_mtd_device(&slave->mtd);
 272 +               mtd_partition_split(master, slave);
 273
 274                 cur_offset = slave->offset + slave->mtd.size;
 275         }
 276 --- a/include/linux/mtd/partitions.h
 277 +++ b/include/linux/mtd/partitions.h
 278 @@ -84,5 +84,7 @@ int mtd_add_partition(struct mtd_info *m
 279                       long long offset, long long length);
 280  int mtd_del_partition(struct mtd_info *master, int partno);
 281  uint64_t mtd_get_device_size(const struct mtd_info *mtd);
 282 +extern void __weak arch_split_mtd_part(struct mtd_info *master,
 283 +                                      const char *name, int offset, int size);
 284
 285  #endif