include/linux/bcm963xx_nvram.h

   1 #ifndef __LINUX_BCM963XX_NVRAM_H__
   2 #define __LINUX_BCM963XX_NVRAM_H__
   3
   4 #include <linux/crc32.h>
   5 #include <linux/if_ether.h>
   6 #include <linux/sizes.h>
   7 #include <linux/types.h>
   8
   9 /*
  10  * Broadcom BCM963xx SoC board nvram data structure.
  11  *
  12  * The nvram structure varies in size depending on the SoC board version. Use
  13  * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
  14  * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
  15  */
  16
  17 #define BCM963XX_NVRAM_V4_SIZE          300
  18 #define BCM963XX_NVRAM_V5_SIZE          (1 * SZ_1K)
  19
  20 #define BCM963XX_DEFAULT_PSI_SIZE       64
  21
  22 enum bcm963xx_nvram_nand_part {
  23         BCM963XX_NVRAM_NAND_PART_BOOT = 0,
  24         BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
  25         BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
  26         BCM963XX_NVRAM_NAND_PART_DATA,
  27         BCM963XX_NVRAM_NAND_PART_BBT,
  28
  29         __BCM963XX_NVRAM_NAND_NR_PARTS
  30 };
  31
  32 struct bcm963xx_nvram {
  33         u32     version;
  34         char    bootline[256];
  35         char    name[16];
  36         u32     main_tp_number;
  37         u32     psi_size;
  38         u32     mac_addr_count;
  39         u8      mac_addr_base[ETH_ALEN];
  40         u8      __reserved1[2];
  41         u32     checksum_v4;
  42
  43         u8      __reserved2[292];
  44         u32     nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
  45         u32     nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
  46         u8      __reserved3[388];
  47         u32     checksum_v5;
  48 };
  49
  50 #define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
  51         bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
  52
  53 static inline u64 __pure bcm963xx_nvram_nand_part_offset(
  54         const struct bcm963xx_nvram *nvram,
  55         enum bcm963xx_nvram_nand_part part)
  56 {
  57         return nvram->nand_part_offset[part] * SZ_1K;
  58 }
  59
  60 #define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
  61         bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
  62
  63 static inline u64 __pure bcm963xx_nvram_nand_part_size(
  64         const struct bcm963xx_nvram *nvram,
  65         enum bcm963xx_nvram_nand_part part)
  66 {
  67         return nvram->nand_part_size[part] * SZ_1K;
  68 }
  69
  70 /*
  71  * bcm963xx_nvram_checksum - Verify nvram checksum
  72  *
  73  * @nvram: pointer to full size nvram data structure
  74  * @expected_out: optional pointer to store expected checksum value
  75  * @actual_out: optional pointer to store actual checksum value
  76  *
  77  * Return: 0 if the checksum is valid, otherwise -EINVAL
  78  */
  79 static int __maybe_unused bcm963xx_nvram_checksum(
  80         const struct bcm963xx_nvram *nvram,
  81         u32 *expected_out, u32 *actual_out)
  82 {
  83         u32 expected, actual;
  84         size_t len;
  85
  86         if (nvram->version <= 4) {
  87                 expected = nvram->checksum_v4;
  88                 len = BCM963XX_NVRAM_V4_SIZE - sizeof(u32);
  89         } else {
  90                 expected = nvram->checksum_v5;
  91                 len = BCM963XX_NVRAM_V5_SIZE - sizeof(u32);
  92         }
  93
  94         /*
  95          * Calculate the CRC32 value for the nvram with a checksum value
  96          * of 0 without modifying or copying the nvram by combining:
  97          * - The CRC32 of the nvram without the checksum value
  98          * - The CRC32 of a zero checksum value (which is also 0)
  99          */
 100         actual = crc32_le_combine(
 101                 crc32_le(~0, (u8 *)nvram, len), 0, sizeof(u32));
 102
 103         if (expected_out)
 104                 *expected_out = expected;
 105
 106         if (actual_out)
 107                 *actual_out = actual;
 108
 109         return expected == actual ? 0 : -EINVAL;
 110 };
 111
 112 #endif /* __LINUX_BCM963XX_NVRAM_H__ */