target/linux/generic/backport-4.9/060-0005-mtd-bcm47xxpart-support-layouts-with-multiple-TRX-pa.patch

   1 From 89a0d9a9f1941a086a82bc7cd73d275cec98ba14 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Tue, 10 Jan 2017 23:15:25 +0100
   4 Subject: [PATCH] mtd: bcm47xxpart: support layouts with multiple TRX
   5  partitions
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 Some devices may have an extra TRX partition used as failsafe one. If
  11 we detect such partition we should set a proper name for it and don't
  12 parse it.
  13
  14 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  15 Acked-by: Marek Vasut <marek.vasut@gmail.com>
  16 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
  17 ---
  18  drivers/mtd/bcm47xxpart.c | 56 ++++++++++++++++++++++++++++++++++++++---------
  19  1 file changed, 46 insertions(+), 10 deletions(-)
  20
  21 --- a/drivers/mtd/bcm47xxpart.c
  22 +++ b/drivers/mtd/bcm47xxpart.c
  23 @@ -9,6 +9,7 @@
  24   *
  25   */
  26
  27 +#include <linux/bcm47xx_nvram.h>
  28  #include <linux/module.h>
  29  #include <linux/kernel.h>
  30  #include <linux/slab.h>
  31 @@ -144,6 +145,30 @@ static int bcm47xxpart_parse_trx(struct
  32         return curr_part;
  33  }
  34
  35 +/**
  36 + * bcm47xxpart_bootpartition - gets index of TRX partition used by bootloader
  37 + *
  38 + * Some devices may have more than one TRX partition. In such case one of them
  39 + * is the main one and another a failsafe one. Bootloader may fallback to the
  40 + * failsafe firmware if it detects corruption of the main image.
  41 + *
  42 + * This function provides info about currently used TRX partition. It's the one
  43 + * containing kernel started by the bootloader.
  44 + */
  45 +static int bcm47xxpart_bootpartition(void)
  46 +{
  47 +       char buf[4];
  48 +       int bootpartition;
  49 +
  50 +       /* Check CFE environment variable */
  51 +       if (bcm47xx_nvram_getenv("bootpartition", buf, sizeof(buf)) > 0) {
  52 +               if (!kstrtoint(buf, 0, &bootpartition))
  53 +                       return bootpartition;
  54 +       }
  55 +
  56 +       return 0;
  57 +}
  58 +
  59  static int bcm47xxpart_parse(struct mtd_info *master,
  60                              const struct mtd_partition **pparts,
  61                              struct mtd_part_parser_data *data)
  62 @@ -154,7 +179,8 @@ static int bcm47xxpart_parse(struct mtd_
  63         size_t bytes_read;
  64         uint32_t offset;
  65         uint32_t blocksize = master->erasesize;
  66 -       int trx_part = -1;
  67 +       int trx_parts[2]; /* Array with indexes of TRX partitions */
  68 +       int trx_num = 0; /* Number of found TRX partitions */
  69         int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
  70         int err;
  71
  72 @@ -243,7 +269,11 @@ static int bcm47xxpart_parse(struct mtd_
  73                 if (buf[0x000 / 4] == TRX_MAGIC) {
  74                         struct trx_header *trx;
  75
  76 -                       trx_part = curr_part;
  77 +                       if (trx_num >= ARRAY_SIZE(trx_parts))
  78 +                               pr_warn("No enough space to store another TRX found at 0x%X\n",
  79 +                                       offset);
  80 +                       else
  81 +                               trx_parts[trx_num++] = curr_part;
  82                         bcm47xxpart_add_part(&parts[curr_part++], "firmware",
  83                                              offset, 0);
  84
  85 @@ -329,14 +359,20 @@ static int bcm47xxpart_parse(struct mtd_
  86         }
  87
  88         /* If there was TRX parse it now */
  89 -       if (trx_part >= 0) {
  90 -               int num_parts;
  91 +       for (i = 0; i < trx_num; i++) {
  92 +               struct mtd_partition *trx = &parts[trx_parts[i]];
  93
  94 -               num_parts = bcm47xxpart_parse_trx(master, &parts[trx_part],
  95 -                                                 parts + curr_part,
  96 -                                                 BCM47XXPART_MAX_PARTS - curr_part);
  97 -               if (num_parts > 0)
  98 -                       curr_part += num_parts;
  99 +               if (i == bcm47xxpart_bootpartition()) {
 100 +                       int num_parts;
 101 +
 102 +                       num_parts = bcm47xxpart_parse_trx(master, trx,
 103 +                                                         parts + curr_part,
 104 +                                                         BCM47XXPART_MAX_PARTS - curr_part);
 105 +                       if (num_parts > 0)
 106 +                               curr_part += num_parts;
 107 +               } else {
 108 +                       trx->name = "failsafe";
 109 +               }
 110         }
 111
 112         *pparts = parts;