include/linux/bcm963xx_nvram.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_BCM963XX_NVRAM_H__
   3 #define __LINUX_BCM963XX_NVRAM_H__
   4
   5 #include <linux/crc32.h>
   6 #include <linux/if_ether.h>
   7 #include <linux/sizes.h>
   8 #include <linux/types.h>
   9
  10 /*
  11  * Broadcom BCM963xx SoC board nvram data structure.
  12  *
  13  * The nvram structure varies in size depending on the SoC board version. Use
  14  * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
  15  * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
  16  */
  17
  18 #define BCM963XX_NVRAM_V4_SIZE          300
  19 #define BCM963XX_NVRAM_V5_SIZE          (1 * SZ_1K)
  20
  21 #define BCM963XX_DEFAULT_PSI_SIZE       64
  22
  23 enum bcm963xx_nvram_nand_part {
  24         BCM963XX_NVRAM_NAND_PART_BOOT = 0,
  25         BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
  26         BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
  27         BCM963XX_NVRAM_NAND_PART_DATA,
  28         BCM963XX_NVRAM_NAND_PART_BBT,
  29
  30         __BCM963XX_NVRAM_NAND_NR_PARTS
  31 };
  32
  33 struct bcm963xx_nvram {
  34         u32     version;
  35         char    bootline[256];
  36         char    name[16];
  37         u32     main_tp_number;
  38         u32     psi_size;
  39         u32     mac_addr_count;
  40         u8      mac_addr_base[ETH_ALEN];
  41         u8      __reserved1[2];
  42         u32     checksum_v4;
  43
  44         u8      __reserved2[292];
  45         u32     nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
  46         u32     nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
  47         u8      __reserved3[388];
  48         u32     checksum_v5;
  49 };
  50
  51 #define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
  52         bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
  53
  54 static inline u64 __pure bcm963xx_nvram_nand_part_offset(
  55         const struct bcm963xx_nvram *nvram,
  56         enum bcm963xx_nvram_nand_part part)
  57 {
  58         return nvram->nand_part_offset[part] * SZ_1K;
  59 }
  60
  61 #define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
  62         bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
  63
  64 static inline u64 __pure bcm963xx_nvram_nand_part_size(
  65         const struct bcm963xx_nvram *nvram,
  66         enum bcm963xx_nvram_nand_part part)
  67 {
  68         return nvram->nand_part_size[part] * SZ_1K;
  69 }
  70
  71 /*
  72  * bcm963xx_nvram_checksum - Verify nvram checksum
  73  *
  74  * @nvram: pointer to full size nvram data structure
  75  * @expected_out: optional pointer to store expected checksum value
  76  * @actual_out: optional pointer to store actual checksum value
  77  *
  78  * Return: 0 if the checksum is valid, otherwise -EINVAL
  79  */
  80 static int __maybe_unused bcm963xx_nvram_checksum(
  81         const struct bcm963xx_nvram *nvram,
  82         u32 *expected_out, u32 *actual_out)
  83 {
  84         u32 expected, actual;
  85         size_t len;
  86
  87         if (nvram->version <= 4) {
  88                 expected = nvram->checksum_v4;
  89                 len = BCM963XX_NVRAM_V4_SIZE - sizeof(u32);
  90         } else {
  91                 expected = nvram->checksum_v5;
  92                 len = BCM963XX_NVRAM_V5_SIZE - sizeof(u32);
  93         }
  94
  95         /*
  96          * Calculate the CRC32 value for the nvram with a checksum value
  97          * of 0 without modifying or copying the nvram by combining:
  98          * - The CRC32 of the nvram without the checksum value
  99          * - The CRC32 of a zero checksum value (which is also 0)
 100          */
 101         actual = crc32_le_combine(
 102                 crc32_le(~0, (u8 *)nvram, len), 0, sizeof(u32));
 103
 104         if (expected_out)
 105                 *expected_out = expected;
 106
 107         if (actual_out)
 108                 *actual_out = actual;
 109
 110         return expected == actual ? 0 : -EINVAL;
 111 };
 112
 113 #endif /* __LINUX_BCM963XX_NVRAM_H__ */