drivers/mtd/parsers/qcomsmempart.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Qualcomm SMEM NAND flash partition parser
   4  *
   5  * Copyright (C) 2020, Linaro Ltd.
   6  */
   7
   8 #include <linux/ctype.h>
   9 #include <linux/module.h>
  10 #include <linux/mtd/mtd.h>
  11 #include <linux/mtd/partitions.h>
  12 #include <linux/slab.h>
  13 #include <linux/soc/qcom/smem.h>
  14
  15 #define SMEM_AARM_PARTITION_TABLE       9
  16 #define SMEM_APPS                       0
  17
  18 #define SMEM_FLASH_PART_MAGIC1          0x55ee73aa
  19 #define SMEM_FLASH_PART_MAGIC2          0xe35ebddb
  20 #define SMEM_FLASH_PTABLE_V3            3
  21 #define SMEM_FLASH_PTABLE_V4            4
  22 #define SMEM_FLASH_PTABLE_MAX_PARTS_V3  16
  23 #define SMEM_FLASH_PTABLE_MAX_PARTS_V4  48
  24 #define SMEM_FLASH_PTABLE_HDR_LEN       (4 * sizeof(u32))
  25 #define SMEM_FLASH_PTABLE_NAME_SIZE     16
  26
  27 /**
  28  * struct smem_flash_pentry - SMEM Flash partition entry
  29  * @name: Name of the partition
  30  * @offset: Offset in blocks
  31  * @length: Length of the partition in blocks
  32  * @attr: Flags for this partition
  33  */
  34 struct smem_flash_pentry {
  35         char name[SMEM_FLASH_PTABLE_NAME_SIZE];
  36         __le32 offset;
  37         __le32 length;
  38         u8 attr;
  39 } __packed __aligned(4);
  40
  41 /**
  42  * struct smem_flash_ptable - SMEM Flash partition table
  43  * @magic1: Partition table Magic 1
  44  * @magic2: Partition table Magic 2
  45  * @version: Partition table version
  46  * @numparts: Number of partitions in this ptable
  47  * @pentry: Flash partition entries belonging to this ptable
  48  */
  49 struct smem_flash_ptable {
  50         __le32 magic1;
  51         __le32 magic2;
  52         __le32 version;
  53         __le32 numparts;
  54         struct smem_flash_pentry pentry[SMEM_FLASH_PTABLE_MAX_PARTS_V4];
  55 } __packed __aligned(4);
  56
  57 static int parse_qcomsmem_part(struct mtd_info *mtd,
  58                                const struct mtd_partition **pparts,
  59                                struct mtd_part_parser_data *data)
  60 {
  61         struct smem_flash_pentry *pentry;
  62         struct smem_flash_ptable *ptable;
  63         size_t len = SMEM_FLASH_PTABLE_HDR_LEN;
  64         struct mtd_partition *parts;
  65         int ret, i, numparts;
  66         char *name, *c;
  67
  68         if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_4K_SECTORS)
  69                         && mtd->type == MTD_NORFLASH) {
  70                 pr_err("%s: SMEM partition parser is incompatible with 4K sectors\n",
  71                                 mtd->name);
  72                 return -EINVAL;
  73         }
  74
  75         pr_debug("Parsing partition table info from SMEM\n");
  76         ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
  77         if (IS_ERR(ptable)) {
  78                 pr_err("Error reading partition table header\n");
  79                 return PTR_ERR(ptable);
  80         }
  81
  82         /* Verify ptable magic */
  83         if (le32_to_cpu(ptable->magic1) != SMEM_FLASH_PART_MAGIC1 ||
  84             le32_to_cpu(ptable->magic2) != SMEM_FLASH_PART_MAGIC2) {
  85                 pr_err("Partition table magic verification failed\n");
  86                 return -EINVAL;
  87         }
  88
  89         /* Ensure that # of partitions is less than the max we have allocated */
  90         numparts = le32_to_cpu(ptable->numparts);
  91         if (numparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
  92                 pr_err("Partition numbers exceed the max limit\n");
  93                 return -EINVAL;
  94         }
  95
  96         /* Find out length of partition data based on table version */
  97         if (le32_to_cpu(ptable->version) <= SMEM_FLASH_PTABLE_V3) {
  98                 len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V3 *
  99                         sizeof(struct smem_flash_pentry);
 100         } else if (le32_to_cpu(ptable->version) == SMEM_FLASH_PTABLE_V4) {
 101                 len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V4 *
 102                         sizeof(struct smem_flash_pentry);
 103         } else {
 104                 pr_err("Unknown ptable version (%d)", le32_to_cpu(ptable->version));
 105                 return -EINVAL;
 106         }
 107
 108         /*
 109          * Now that the partition table header has been parsed, verified
 110          * and the length of the partition table calculated, read the
 111          * complete partition table
 112          */
 113         ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
 114         if (IS_ERR(ptable)) {
 115                 pr_err("Error reading partition table\n");
 116                 return PTR_ERR(ptable);
 117         }
 118
 119         parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);
 120         if (!parts)
 121                 return -ENOMEM;
 122
 123         for (i = 0; i < numparts; i++) {
 124                 pentry = &ptable->pentry[i];
 125                 if (pentry->name[0] == '\0')
 126                         continue;
 127
 128                 name = kstrdup(pentry->name, GFP_KERNEL);
 129                 if (!name) {
 130                         ret = -ENOMEM;
 131                         goto out_free_parts;
 132                 }
 133
 134                 /* Convert name to lower case */
 135                 for (c = name; *c != '\0'; c++)
 136                         *c = tolower(*c);
 137
 138                 parts[i].name = name;
 139                 parts[i].offset = le32_to_cpu(pentry->offset) * mtd->erasesize;
 140                 parts[i].mask_flags = pentry->attr;
 141                 parts[i].size = le32_to_cpu(pentry->length) * mtd->erasesize;
 142                 pr_debug("%d: %s offs=0x%08x size=0x%08x attr:0x%08x\n",
 143                          i, pentry->name, le32_to_cpu(pentry->offset),
 144                          le32_to_cpu(pentry->length), pentry->attr);
 145         }
 146
 147         pr_debug("SMEM partition table found: ver: %d len: %d\n",
 148                  le32_to_cpu(ptable->version), numparts);
 149         *pparts = parts;
 150
 151         return numparts;
 152
 153 out_free_parts:
 154         while (--i >= 0)
 155                 kfree(parts[i].name);
 156         kfree(parts);
 157         *pparts = NULL;
 158
 159         return ret;
 160 }
 161
 162 static void parse_qcomsmem_cleanup(const struct mtd_partition *pparts,
 163                                    int nr_parts)
 164 {
 165         int i;
 166
 167         for (i = 0; i < nr_parts; i++)
 168                 kfree(pparts[i].name);
 169 }
 170
 171 static const struct of_device_id qcomsmem_of_match_table[] = {
 172         { .compatible = "qcom,smem-part" },
 173         {},
 174 };
 175 MODULE_DEVICE_TABLE(of, qcomsmem_of_match_table);
 176
 177 static struct mtd_part_parser mtd_parser_qcomsmem = {
 178         .parse_fn = parse_qcomsmem_part,
 179         .cleanup = parse_qcomsmem_cleanup,
 180         .name = "qcomsmem",
 181         .of_match_table = qcomsmem_of_match_table,
 182 };
 183 module_mtd_part_parser(mtd_parser_qcomsmem);
 184
 185 MODULE_LICENSE("GPL v2");
 186 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
 187 MODULE_DESCRIPTION("Qualcomm SMEM NAND flash partition parser");