include/linux/bcm963xx_nvram.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef __LINUX_BCM963XX_NVRAM_H__
0003 #define __LINUX_BCM963XX_NVRAM_H__
0004
0005 #include <linux/crc32.h>
0006 #include <linux/if_ether.h>
0007 #include <linux/sizes.h>
0008 #include <linux/types.h>
0009
0010 /*
0011  * Broadcom BCM963xx SoC board nvram data structure.
0012  *
0013  * The nvram structure varies in size depending on the SoC board version. Use
0014  * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
0015  * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
0016  */
0017
0018 #define BCM963XX_NVRAM_V4_SIZE      300
0019 #define BCM963XX_NVRAM_V5_SIZE      (1 * SZ_1K)
0020
0021 #define BCM963XX_DEFAULT_PSI_SIZE   64
0022
0023 enum bcm963xx_nvram_nand_part {
0024     BCM963XX_NVRAM_NAND_PART_BOOT = 0,
0025     BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
0026     BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
0027     BCM963XX_NVRAM_NAND_PART_DATA,
0028     BCM963XX_NVRAM_NAND_PART_BBT,
0029
0030     __BCM963XX_NVRAM_NAND_NR_PARTS
0031 };
0032
0033 struct bcm963xx_nvram {
0034     u32 version;
0035     char    bootline[256];
0036     char    name[16];
0037     u32 main_tp_number;
0038     u32 psi_size;
0039     u32 mac_addr_count;
0040     u8  mac_addr_base[ETH_ALEN];
0041     u8  __reserved1[2];
0042     u32 checksum_v4;
0043
0044     u8  __reserved2[292];
0045     u32 nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
0046     u32 nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
0047     u8  __reserved3[388];
0048     u32 checksum_v5;
0049 };
0050
0051 #define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
0052     bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
0053
0054 static inline u64 __pure bcm963xx_nvram_nand_part_offset(
0055     const struct bcm963xx_nvram *nvram,
0056     enum bcm963xx_nvram_nand_part part)
0057 {
0058     return nvram->nand_part_offset[part] * SZ_1K;
0059 }
0060
0061 #define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
0062     bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)
0063
0064 static inline u64 __pure bcm963xx_nvram_nand_part_size(
0065     const struct bcm963xx_nvram *nvram,
0066     enum bcm963xx_nvram_nand_part part)
0067 {
0068     return nvram->nand_part_size[part] * SZ_1K;
0069 }
0070
0071 /*
0072  * bcm963xx_nvram_checksum - Verify nvram checksum
0073  *
0074  * @nvram: pointer to full size nvram data structure
0075  * @expected_out: optional pointer to store expected checksum value
0076  * @actual_out: optional pointer to store actual checksum value
0077  *
0078  * Return: 0 if the checksum is valid, otherwise -EINVAL
0079  */
0080 static int __maybe_unused bcm963xx_nvram_checksum(
0081     const struct bcm963xx_nvram *nvram,
0082     u32 *expected_out, u32 *actual_out)
0083 {
0084     u32 expected, actual;
0085     size_t len;
0086
0087     if (nvram->version <= 4) {
0088         expected = nvram->checksum_v4;
0089         len = BCM963XX_NVRAM_V4_SIZE - sizeof(u32);
0090     } else {
0091         expected = nvram->checksum_v5;
0092         len = BCM963XX_NVRAM_V5_SIZE - sizeof(u32);
0093     }
0094
0095     /*
0096      * Calculate the CRC32 value for the nvram with a checksum value
0097      * of 0 without modifying or copying the nvram by combining:
0098      * - The CRC32 of the nvram without the checksum value
0099      * - The CRC32 of a zero checksum value (which is also 0)
0100      */
0101     actual = crc32_le_combine(
0102         crc32_le(~0, (u8 *)nvram, len), 0, sizeof(u32));
0103
0104     if (expected_out)
0105         *expected_out = expected;
0106
0107     if (actual_out)
0108         *actual_out = actual;
0109
0110     return expected == actual ? 0 : -EINVAL;
0111 };
0112
0113 #endif /* __LINUX_BCM963XX_NVRAM_H__ */