target/linux/generic/patches-4.4/141-0001-mtd-bcm47xxpart-move-TRX-parsing-code-to-separated-f.patch

   1 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   2 Subject: [PATCH 1/2] mtd: bcm47xxpart: move TRX parsing code to separated
   3  function
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   6 Content-Transfer-Encoding: 8bit
   7
   8 This change simplifies main parsing loop logic a bit. In future it may
   9 be useful for moving TRX support to separated module / parser (if we
  10 implement support for them at some point).
  11 Finally parsing TRX at the end puts us in a better position as we have
  12 better flash layout knowledge. It may be useful e.g. if it appears there
  13 is more than 1 TRX partition.
  14
  15 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  16 ---
  17  drivers/mtd/bcm47xxpart.c | 124 ++++++++++++++++++++++++++++------------------
  18  1 file changed, 77 insertions(+), 47 deletions(-)
  19
  20 --- a/drivers/mtd/bcm47xxpart.c
  21 +++ b/drivers/mtd/bcm47xxpart.c
  22 @@ -83,6 +83,70 @@ out_default:
  23         return "rootfs";
  24  }
  25
  26 +static int bcm47xxpart_parse_trx(struct mtd_info *master,
  27 +                                struct mtd_partition *trx,
  28 +                                struct mtd_partition *parts,
  29 +                                size_t parts_len)
  30 +{
  31 +       struct mtd_partition *part;
  32 +       struct trx_header header;
  33 +       size_t bytes_read;
  34 +       int curr_part = 0;
  35 +       int i, err;
  36 +
  37 +       if (parts_len < 3) {
  38 +               pr_warn("No enough space to add TRX partitions!\n");
  39 +               return -ENOMEM;
  40 +       }
  41 +
  42 +       err = mtd_read(master, trx->offset, sizeof(header), &bytes_read,
  43 +                      (uint8_t *)&header);
  44 +       if (err && !mtd_is_bitflip(err)) {
  45 +               pr_err("mtd_read error while reading TRX header: %d\n", err);
  46 +               return err;
  47 +       }
  48 +
  49 +       i = 0;
  50 +
  51 +       /* We have LZMA loader if offset[2] points to sth */
  52 +       if (header.offset[2]) {
  53 +               part = &parts[curr_part++];
  54 +               part->name = "loader";
  55 +               part->offset = trx->offset + header.offset[i];
  56 +               i++;
  57 +       }
  58 +
  59 +       if (header.offset[i]) {
  60 +               part = &parts[curr_part++];
  61 +               part->name = "linux";
  62 +               part->offset = trx->offset + header.offset[i];
  63 +               i++;
  64 +       }
  65 +
  66 +       if (header.offset[i]) {
  67 +               size_t offset = trx->offset + header.offset[i];
  68 +
  69 +               part = &parts[curr_part++];
  70 +               part->name = bcm47xxpart_trx_data_part_name(master, offset);
  71 +               part->offset = offset;
  72 +               i++;
  73 +       }
  74 +
  75 +       /*
  76 +        * Assume that every partition ends at the beginning of the one it is
  77 +        * followed by.
  78 +        */
  79 +       for (i = 0; i < curr_part; i++) {
  80 +               u64 next_part_offset = (i < curr_part - 1) ?
  81 +                                       parts[i + 1].offset :
  82 +                                       trx->offset + trx->size;
  83 +
  84 +               parts[i].size = next_part_offset - parts[i].offset;
  85 +       }
  86 +
  87 +       return curr_part;
  88 +}
  89 +
  90  static int bcm47xxpart_parse(struct mtd_info *master,
  91                              struct mtd_partition **pparts,
  92                              struct mtd_part_parser_data *data)
  93 @@ -93,9 +157,7 @@ static int bcm47xxpart_parse(struct mtd_
  94         size_t bytes_read;
  95         uint32_t offset;
  96         uint32_t blocksize = master->erasesize;
  97 -       struct trx_header *trx;
  98         int trx_part = -1;
  99 -       int last_trx_part = -1;
 100         int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
 101         int err;
 102
 103 @@ -182,54 +244,14 @@ static int bcm47xxpart_parse(struct mtd_
 104
 105                 /* TRX */
 106                 if (buf[0x000 / 4] == TRX_MAGIC) {
 107 -                       if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
 108 -                               pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
 109 -                               break;
 110 -                       }
 111 -
 112 -                       trx = (struct trx_header *)buf;
 113 +                       struct trx_header *trx;
 114
 115                         trx_part = curr_part;
 116                         bcm47xxpart_add_part(&parts[curr_part++], "firmware",
 117                                              offset, 0);
 118
 119 -                       i = 0;
 120 -                       /* We have LZMA loader if offset[2] points to sth */
 121 -                       if (trx->offset[2]) {
 122 -                               bcm47xxpart_add_part(&parts[curr_part++],
 123 -                                                    "loader",
 124 -                                                    offset + trx->offset[i],
 125 -                                                    0);
 126 -                               i++;
 127 -                       }
 128 -
 129 -                       if (trx->offset[i]) {
 130 -                               bcm47xxpart_add_part(&parts[curr_part++],
 131 -                                                    "linux",
 132 -                                                    offset + trx->offset[i],
 133 -                                                    0);
 134 -                               i++;
 135 -                       }
 136 -
 137 -                       /*
 138 -                        * Pure rootfs size is known and can be calculated as:
 139 -                        * trx->length - trx->offset[i]. We don't fill it as
 140 -                        * we want to have jffs2 (overlay) in the same mtd.
 141 -                        */
 142 -                       if (trx->offset[i]) {
 143 -                               const char *name;
 144 -
 145 -                               name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]);
 146 -                               bcm47xxpart_add_part(&parts[curr_part++],
 147 -                                                    name,
 148 -                                                    offset + trx->offset[i],
 149 -                                                    0);
 150 -                               i++;
 151 -                       }
 152 -
 153 -                       last_trx_part = curr_part - 1;
 154 -
 155                         /* Jump to the end of TRX */
 156 +                       trx = (struct trx_header *)buf;
 157                         offset = roundup(offset + trx->length, blocksize);
 158                         /* Next loop iteration will increase the offset */
 159                         offset -= blocksize;
 160 @@ -307,9 +329,17 @@ static int bcm47xxpart_parse(struct mtd_
 161                                        parts[i + 1].offset : master->size;
 162
 163                 parts[i].size = next_part_offset - parts[i].offset;
 164 -               if (i == last_trx_part && trx_part >= 0)
 165 -                       parts[trx_part].size = next_part_offset -
 166 -                                              parts[trx_part].offset;
 167 +       }
 168 +
 169 +       /* If there was TRX parse it now */
 170 +       if (trx_part >= 0) {
 171 +               int num_parts;
 172 +
 173 +               num_parts = bcm47xxpart_parse_trx(master, &parts[trx_part],
 174 +                                                 parts + curr_part,
 175 +                                                 BCM47XXPART_MAX_PARTS - curr_part);
 176 +               if (num_parts > 0)
 177 +                       curr_part += num_parts;
 178         }
 179
 180         *pparts = parts;