// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * BCM63XX CFE image tag parser
 *
 * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
 *                        Mike Albon <malbon@openwrt.org>
 * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
 * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bcm963xx_nvram.h>
#include <linux/bcm963xx_tag.h>
#include <linux/crc32.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/of.h>

#ifdef CONFIG_MIPS
#include <asm/bootinfo.h>
#include <asm/fw/cfe/cfe_api.h>
#endif /* CONFIG_MIPS */

#define BCM963XX_CFE_BLOCK_SIZE         SZ_64K  /* always at least 64KiB */

#define BCM963XX_CFE_MAGIC_OFFSET       0x4e0
#define BCM963XX_CFE_VERSION_OFFSET     0x570
#define BCM963XX_NVRAM_OFFSET           0x580

/* Ensure strings read from flash structs are null terminated */
#define STR_NULL_TERMINATE(x) \
        do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)

static inline int bcm63xx_detect_cfe(void)
{
        int ret = 0;

#ifdef CONFIG_MIPS
        ret = (fw_arg3 == CFE_EPTSEAL);
#endif /* CONFIG_MIPS */

        return ret;
}

static int bcm63xx_read_nvram(struct mtd_info *master,
        struct bcm963xx_nvram *nvram)
{
        u32 actual_crc, expected_crc;
        size_t retlen;
        int ret;

        /* extract nvram data */
        ret = mtd_read(master, BCM963XX_NVRAM_OFFSET, BCM963XX_NVRAM_V5_SIZE,
                        &retlen, (void *)nvram);
        if (ret)
                return ret;

        ret = bcm963xx_nvram_checksum(nvram, &expected_crc, &actual_crc);
        if (ret)
                pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
                        expected_crc, actual_crc);

        if (!nvram->psi_size)
                nvram->psi_size = BCM963XX_DEFAULT_PSI_SIZE;

        return 0;
}

static const char * const bcm63xx_cfe_part_types[] = {
        "bcm963xx-imagetag",
        NULL,
};

static int bcm63xx_parse_cfe_nor_partitions(struct mtd_info *master,
        const struct mtd_partition **pparts, struct bcm963xx_nvram *nvram)
{
        struct mtd_partition *parts;
        int nrparts = 3, curpart = 0;
        unsigned int cfelen, nvramlen;
        unsigned int cfe_erasesize;
        int i;

        cfe_erasesize = max_t(uint32_t, master->erasesize,
                              BCM963XX_CFE_BLOCK_SIZE);

        cfelen = cfe_erasesize;
        nvramlen = nvram->psi_size * SZ_1K;
        nvramlen = roundup(nvramlen, cfe_erasesize);

        parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
        if (!parts)
                return -ENOMEM;

        /* Start building partition list */
        parts[curpart].name = "CFE";
        parts[curpart].offset = 0;
        parts[curpart].size = cfelen;
        curpart++;

        parts[curpart].name = "nvram";
        parts[curpart].offset = master->size - nvramlen;
        parts[curpart].size = nvramlen;
        curpart++;

        /* Global partition "linux" to make easy firmware upgrade */
        parts[curpart].name = "linux";
        parts[curpart].offset = cfelen;
        parts[curpart].size = master->size - cfelen - nvramlen;
        parts[curpart].types = bcm63xx_cfe_part_types;

        for (i = 0; i < nrparts; i++)
                pr_info("Partition %d is %s offset %llx and length %llx\n", i,
                        parts[i].name, parts[i].offset, parts[i].size);

        *pparts = parts;

        return nrparts;
}

static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
                                        const struct mtd_partition **pparts,
                                        struct mtd_part_parser_data *data)
{
        struct bcm963xx_nvram *nvram = NULL;
        int ret;

        if (!bcm63xx_detect_cfe())
                return -EINVAL;

        nvram = vzalloc(sizeof(*nvram));
        if (!nvram)
                return -ENOMEM;

        ret = bcm63xx_read_nvram(master, nvram);
        if (ret)
                goto out;

        if (!mtd_type_is_nand(master))
                ret = bcm63xx_parse_cfe_nor_partitions(master, pparts, nvram);
        else
                ret = -EINVAL;

out:
        vfree(nvram);
        return ret;
};

static const struct of_device_id parse_bcm63xx_cfe_match_table[] = {
        { .compatible = "brcm,bcm963xx-cfe-nor-partitions" },
        {},
};
MODULE_DEVICE_TABLE(of, parse_bcm63xx_cfe_match_table);

static struct mtd_part_parser bcm63xx_cfe_parser = {
        .parse_fn = bcm63xx_parse_cfe_partitions,
        .name = "bcm63xxpart",
        .of_match_table = parse_bcm63xx_cfe_match_table,
};
module_mtd_part_parser(bcm63xx_cfe_parser);

MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");