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
   4 MIME-Version: 1.0
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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 | 121 ++++++++++++++++++++++++++++------------------
  18  1 file changed, 74 insertions(+), 47 deletions(-)
  19
  20 --- a/drivers/mtd/bcm47xxpart.c
  21 +++ b/drivers/mtd/bcm47xxpart.c
  22 @@ -83,6 +83,67 @@ 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 trx_header header;
  32 +       size_t bytes_read;
  33 +       int curr_part = 0;
  34 +       int i, err;
  35 +
  36 +       if (parts_len < 3) {
  37 +               pr_warn("No enough space to add TRX partitions!\n");
  38 +               return -ENOMEM;
  39 +       }
  40 +
  41 +       err = mtd_read(master, trx->offset, sizeof(header), &bytes_read,
  42 +                      (uint8_t *)&header);
  43 +       if (err && !mtd_is_bitflip(err)) {
  44 +               pr_err("mtd_read error while reading TRX header: %d\n", err);
  45 +               return err;
  46 +       }
  47 +
  48 +       i = 0;
  49 +
  50 +       /* We have LZMA loader if offset[2] points to sth */
  51 +       if (header.offset[2]) {
  52 +               bcm47xxpart_add_part(&parts[curr_part++], "loader",
  53 +                                    trx->offset + header.offset[i], 0);
  54 +               i++;
  55 +       }
  56 +
  57 +       if (header.offset[i]) {
  58 +               bcm47xxpart_add_part(&parts[curr_part++], "linux",
  59 +                                    trx->offset + header.offset[i], 0);
  60 +               i++;
  61 +       }
  62 +
  63 +       if (header.offset[i]) {
  64 +               size_t offset = trx->offset + header.offset[i];
  65 +               const char *name = bcm47xxpart_trx_data_part_name(master,
  66 +                                                                 offset);
  67 +
  68 +               bcm47xxpart_add_part(&parts[curr_part++], name, offset, 0);
  69 +               i++;
  70 +       }
  71 +
  72 +       /*
  73 +        * Assume that every partition ends at the beginning of the one it is
  74 +        * followed by.
  75 +        */
  76 +       for (i = 0; i < curr_part; i++) {
  77 +               u64 next_part_offset = (i < curr_part - 1) ?
  78 +                                       parts[i + 1].offset :
  79 +                                       trx->offset + trx->size;
  80 +
  81 +               parts[i].size = next_part_offset - parts[i].offset;
  82 +       }
  83 +
  84 +       return curr_part;
  85 +}
  86 +
  87  static int bcm47xxpart_parse(struct mtd_info *master,
  88                              struct mtd_partition **pparts,
  89                              struct mtd_part_parser_data *data)
  90 @@ -93,9 +154,7 @@ static int bcm47xxpart_parse(struct mtd_
  91         size_t bytes_read;
  92         uint32_t offset;
  93         uint32_t blocksize = master->erasesize;
  94 -       struct trx_header *trx;
  95         int trx_part = -1;
  96 -       int last_trx_part = -1;
  97         int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
  98         int err;
  99
 100 @@ -182,54 +241,14 @@ static int bcm47xxpart_parse(struct mtd_
 101
 102                 /* TRX */
 103                 if (buf[0x000 / 4] == TRX_MAGIC) {
 104 -                       if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
 105 -                               pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
 106 -                               break;
 107 -                       }
 108 -
 109 -                       trx = (struct trx_header *)buf;
 110 +                       struct trx_header *trx;
 111
 112                         trx_part = curr_part;
 113                         bcm47xxpart_add_part(&parts[curr_part++], "firmware",
 114                                              offset, 0);
 115
 116 -                       i = 0;
 117 -                       /* We have LZMA loader if offset[2] points to sth */
 118 -                       if (trx->offset[2]) {
 119 -                               bcm47xxpart_add_part(&parts[curr_part++],
 120 -                                                    "loader",
 121 -                                                    offset + trx->offset[i],
 122 -                                                    0);
 123 -                               i++;
 124 -                       }
 125 -
 126 -                       if (trx->offset[i]) {
 127 -                               bcm47xxpart_add_part(&parts[curr_part++],
 128 -                                                    "linux",
 129 -                                                    offset + trx->offset[i],
 130 -                                                    0);
 131 -                               i++;
 132 -                       }
 133 -
 134 -                       /*
 135 -                        * Pure rootfs size is known and can be calculated as:
 136 -                        * trx->length - trx->offset[i]. We don't fill it as
 137 -                        * we want to have jffs2 (overlay) in the same mtd.
 138 -                        */
 139 -                       if (trx->offset[i]) {
 140 -                               const char *name;
 141 -
 142 -                               name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]);
 143 -                               bcm47xxpart_add_part(&parts[curr_part++],
 144 -                                                    name,
 145 -                                                    offset + trx->offset[i],
 146 -                                                    0);
 147 -                               i++;
 148 -                       }
 149 -
 150 -                       last_trx_part = curr_part - 1;
 151 -
 152                         /* Jump to the end of TRX */
 153 +                       trx = (struct trx_header *)buf;
 154                         offset = roundup(offset + trx->length, blocksize);
 155                         /* Next loop iteration will increase the offset */
 156                         offset -= blocksize;
 157 @@ -307,9 +326,17 @@ static int bcm47xxpart_parse(struct mtd_
 158                                        parts[i + 1].offset : master->size;
 159
 160                 parts[i].size = next_part_offset - parts[i].offset;
 161 -               if (i == last_trx_part && trx_part >= 0)
 162 -                       parts[trx_part].size = next_part_offset -
 163 -                                              parts[trx_part].offset;
 164 +       }
 165 +
 166 +       /* If there was TRX parse it now */
 167 +       if (trx_part >= 0) {
 168 +               int num_parts;
 169 +
 170 +               num_parts = bcm47xxpart_parse_trx(master, &parts[trx_part],
 171 +                                                 parts + curr_part,
 172 +                                                 BCM47XXPART_MAX_PARTS - curr_part);
 173 +               if (num_parts > 0)
 174 +                       curr_part += num_parts;
 175         }
 176
 177         *pparts = parts;