/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_BCM963XX_NVRAM_H__
#define __LINUX_BCM963XX_NVRAM_H__

#include <linux/crc32.h>
#include <linux/if_ether.h>
#include <linux/sizes.h>
#include <linux/types.h>

/*
 * Broadcom BCM963xx SoC board nvram data structure.
 *
 * The nvram structure varies in size depending on the SoC board version. Use
 * the appropriate minimum BCM963XX_NVRAM_*_SIZE define for the information
 * you need instead of sizeof(struct bcm963xx_nvram) as this may change.
 */

#define BCM963XX_NVRAM_V4_SIZE          300
#define BCM963XX_NVRAM_V5_SIZE          (1 * SZ_1K)

#define BCM963XX_DEFAULT_PSI_SIZE       64

enum bcm963xx_nvram_nand_part {
        BCM963XX_NVRAM_NAND_PART_BOOT = 0,
        BCM963XX_NVRAM_NAND_PART_ROOTFS_1,
        BCM963XX_NVRAM_NAND_PART_ROOTFS_2,
        BCM963XX_NVRAM_NAND_PART_DATA,
        BCM963XX_NVRAM_NAND_PART_BBT,

        __BCM963XX_NVRAM_NAND_NR_PARTS
};

struct bcm963xx_nvram {
        u32     version;
        char    bootline[256];
        char    name[16];
        u32     main_tp_number;
        u32     psi_size;
        u32     mac_addr_count;
        u8      mac_addr_base[ETH_ALEN];
        u8      __reserved1[2];
        u32     checksum_v4;

        u8      __reserved2[292];
        u32     nand_part_offset[__BCM963XX_NVRAM_NAND_NR_PARTS];
        u32     nand_part_size[__BCM963XX_NVRAM_NAND_NR_PARTS];
        u8      __reserved3[388];
        u32     checksum_v5;
};

#define BCM963XX_NVRAM_NAND_PART_OFFSET(nvram, part) \
        bcm963xx_nvram_nand_part_offset(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)

static inline u64 __pure bcm963xx_nvram_nand_part_offset(
        const struct bcm963xx_nvram *nvram,
        enum bcm963xx_nvram_nand_part part)
{
        return nvram->nand_part_offset[part] * SZ_1K;
}

#define BCM963XX_NVRAM_NAND_PART_SIZE(nvram, part) \
        bcm963xx_nvram_nand_part_size(nvram, BCM963XX_NVRAM_NAND_PART_ ##part)

static inline u64 __pure bcm963xx_nvram_nand_part_size(
        const struct bcm963xx_nvram *nvram,
        enum bcm963xx_nvram_nand_part part)
{
        return nvram->nand_part_size[part] * SZ_1K;
}

/*
 * bcm963xx_nvram_checksum - Verify nvram checksum
 *
 * @nvram: pointer to full size nvram data structure
 * @expected_out: optional pointer to store expected checksum value
 * @actual_out: optional pointer to store actual checksum value
 *
 * Return: 0 if the checksum is valid, otherwise -EINVAL
 */
static int __maybe_unused bcm963xx_nvram_checksum(
        const struct bcm963xx_nvram *nvram,
        u32 *expected_out, u32 *actual_out)
{
        const u32 zero = 0;
        u32 expected, actual;
        size_t len;

        if (nvram->version <= 4) {
                expected = nvram->checksum_v4;
                len = BCM963XX_NVRAM_V4_SIZE;
        } else {
                expected = nvram->checksum_v5;
                len = BCM963XX_NVRAM_V5_SIZE;
        }

        /* Calculate the CRC32 of the nvram with the checksum field set to 0. */
        actual = crc32_le(~0, nvram, len - sizeof(u32));
        actual = crc32_le(actual, &zero, sizeof(u32));

        if (expected_out)
                *expected_out = expected;

        if (actual_out)
                *actual_out = actual;

        return expected == actual ? 0 : -EINVAL;
};

#endif /* __LINUX_BCM963XX_NVRAM_H__ */