/*
 * Copyright 2016 NXP Semiconductor, Inc.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <errno.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/types.h>
#include <asm/macro.h>
#include <asm/armv8/sec_firmware.h>

DECLARE_GLOBAL_DATA_PTR;
extern void c_runtime_cpu_setup(void);

#define SEC_FIRMWARE_LOADED     0x1
#define SEC_FIRMWARE_RUNNING    0x2
#define SEC_FIRMWARE_ADDR_MASK  (~0x3)
/*
 * Secure firmware load addr
 * Flags used: 0x1 secure firmware has been loaded to secure memory
 *             0x2 secure firmware is running
 */
phys_addr_t sec_firmware_addr;

#ifndef SEC_FIRMWARE_FIT_IMAGE
#define SEC_FIRMWARE_FIT_IMAGE          "firmware"
#endif
#ifndef SEC_FIRMEWARE_FIT_CNF_NAME
#define SEC_FIRMEWARE_FIT_CNF_NAME      "config@1"
#endif
#ifndef SEC_FIRMWARE_TARGET_EL
#define SEC_FIRMWARE_TARGET_EL          2
#endif

static int sec_firmware_get_data(const void *sec_firmware_img,
                                const void **data, size_t *size)
{
        int conf_node_off, fw_node_off;
        char *conf_node_name = NULL;
        char *desc;
        int ret;

        conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;

        conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
        if (conf_node_off < 0) {
                printf("SEC Firmware: %s: no such config\n", conf_node_name);
                return -ENOENT;
        }

        fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
                        SEC_FIRMWARE_FIT_IMAGE);
        if (fw_node_off < 0) {
                printf("SEC Firmware: No '%s' in config\n",
                       SEC_FIRMWARE_FIT_IMAGE);
                return -ENOLINK;
        }

        /* Verify secure firmware image */
        if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
                printf("SEC Firmware: Bad firmware image (bad CRC)\n");
                return -EINVAL;
        }

        if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
                printf("SEC Firmware: Can't get %s subimage data/size",
                       SEC_FIRMWARE_FIT_IMAGE);
                return -ENOENT;
        }

        ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
        if (ret)
                printf("SEC Firmware: Can't get description\n");
        else
                printf("%s\n", desc);

        return ret;
}

/*
 * SEC Firmware FIT image parser checks if the image is in FIT
 * format, verifies integrity of the image and calculates raw
 * image address and size values.
 *
 * Returns 0 on success and a negative errno on error task fail.
 */
static int sec_firmware_parse_image(const void *sec_firmware_img,
                                        const void **raw_image_addr,
                                        size_t *raw_image_size)
{
        int ret;

        ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
                                        raw_image_size);
        if (ret)
                return ret;

        debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
              *raw_image_addr, *raw_image_size);

        return 0;
}

/*
 * SEC Firmware FIT image parser to check if any loadable is
 * present. If present, verify integrity of the loadable and
 * copy loadable to address provided in (loadable_h, loadable_l).
 *
 * Returns 0 on success and a negative errno on error task fail.
 */
static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
                                            u32 *loadable_l, u32 *loadable_h)
{
        phys_addr_t sec_firmware_loadable_addr = 0;
        int conf_node_off, ld_node_off;
        char *conf_node_name = NULL;
        const void *data;
        size_t size;
        ulong load;

        conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;

        conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
        if (conf_node_off < 0) {
                printf("SEC Firmware: %s: no such config\n", conf_node_name);
        return -ENOENT;
        }

        ld_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
                                             FIT_LOADABLE_PROP);
        if (ld_node_off >= 0) {
                printf("SEC Firmware: '%s' present in config\n",
                       FIT_LOADABLE_PROP);

                /* Verify secure firmware image */
                if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
                        printf("SEC Loadable: Bad loadable image (bad CRC)\n");
                        return -EINVAL;
                }

                if (fit_image_get_data(sec_firmware_img, ld_node_off,
                                       &data, &size)) {
                        printf("SEC Loadable: Can't get subimage data/size");
                        return -ENOENT;
                }

                /* Get load address, treated as load offset to secure memory */
                if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
                        printf("SEC Loadable: Can't get subimage load");
                        return -ENOENT;
                }

                /* Compute load address for loadable in secure memory */
                sec_firmware_loadable_addr = (sec_firmware_addr -
                                                gd->arch.tlb_size) + load;

                /* Copy loadable to secure memory and flush dcache */
                debug("%s copied to address 0x%p\n",
                      FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
                memcpy((void *)sec_firmware_loadable_addr, data, size);
                flush_dcache_range(sec_firmware_loadable_addr,
                                   sec_firmware_loadable_addr + size);
        }

        /* Populate address ptrs for loadable image with loadbale addr */
        out_le32(loadable_l, (sec_firmware_loadable_addr & WORD_MASK));
        out_le32(loadable_h, (sec_firmware_loadable_addr >> WORD_SHIFT));

        return 0;
}

static int sec_firmware_copy_image(const char *title,
                         u64 image_addr, u32 image_size, u64 sec_firmware)
{
        debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
        memcpy((void *)sec_firmware, (void *)image_addr, image_size);
        flush_dcache_range(sec_firmware, sec_firmware + image_size);

        return 0;
}

/*
 * This function will parse the SEC Firmware image, and then load it
 * to secure memory. Also load any loadable if present along with SEC
 * Firmware image.
 */
static int sec_firmware_load_image(const void *sec_firmware_img,
                                   u32 *loadable_l, u32 *loadable_h)
{
        const void *raw_image_addr;
        size_t raw_image_size = 0;
        int ret;

        /*
         * The Excetpion Level must be EL3 to load and initialize
         * the SEC Firmware.
         */
        if (current_el() != 3) {
                ret = -EACCES;
                goto out;
        }

#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
        /*
         * The SEC Firmware must be stored in secure memory.
         * Append SEC Firmware to secure mmu table.
         */
        if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
                ret = -ENXIO;
                goto out;
        }

        sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
                        gd->arch.tlb_size;
#else
#error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
#endif

        /* Align SEC Firmware base address to 4K */
        sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
        debug("SEC Firmware: Load address: 0x%llx\n",
              sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);

        ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
                        &raw_image_size);
        if (ret)
                goto out;

        /* TODO:
         * Check if the end addr of SEC Firmware has been extend the secure
         * memory.
         */

        /* Copy the secure firmware to secure memory */
        ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
                        raw_image_size, sec_firmware_addr &
                        SEC_FIRMWARE_ADDR_MASK);
        if (ret)
                goto out;

        /*
         * Check if any loadable are present along with firmware image, if
         * present load them.
         */
        ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
                                               loadable_h);
        if (ret)
                goto out;

        sec_firmware_addr |= SEC_FIRMWARE_LOADED;
        debug("SEC Firmware: Entry point: 0x%llx\n",
              sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);

        return 0;

out:
        printf("SEC Firmware: error (%d)\n", ret);
        sec_firmware_addr = 0;

        return ret;
}

static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
{
        const void *entry = (void *)(sec_firmware_addr &
                                SEC_FIRMWARE_ADDR_MASK);

        return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
}

/* Check the secure firmware FIT image */
__weak bool sec_firmware_is_valid(const void *sec_firmware_img)
{
        if (fdt_check_header(sec_firmware_img)) {
                printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
                return false;
        }

        if (!fit_check_format(sec_firmware_img)) {
                printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
                return false;
        }

        return true;
}

#ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
/*
 * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 * number will be returned according to SMC Calling Conventions. But
 * when getting the NOT_SUPPORTED error number, we cannot ensure if
 * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 * won't be supported by this framework.
 * And if the secure firmware isn't running, return NOT_SUPPORTED.
 *
 * The return value on success is PSCI version in format
 * major[31:16]:minor[15:0].
 */
unsigned int sec_firmware_support_psci_version(void)
{
        if (current_el() == SEC_FIRMWARE_TARGET_EL)
                return _sec_firmware_support_psci_version();

        return PSCI_INVALID_VER;
}
#endif

/*
 * Check with sec_firmware if it supports random number generation
 * via HW RNG
 *
 * The return value will be true if it is supported
 */
bool sec_firmware_support_hwrng(void)
{
        uint8_t rand[8];
        if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
                if (!sec_firmware_get_random(rand, 8))
                        return true;
        }

        return false;
}

/*
 * sec_firmware_get_random - Get a random number from SEC Firmware
 * @rand:               random number buffer to be filled
 * @bytes:              Number of bytes of random number to be supported
 * @eret:               -1 in case of error, 0 for success
 */
int sec_firmware_get_random(uint8_t *rand, int bytes)
{
        unsigned long long num;
        struct pt_regs regs;
        int param1;

        if (!bytes || bytes > 8) {
                printf("Max Random bytes genration supported is 8\n");
                return -1;
        }
#define SIP_RNG_64 0xC200FF11
        regs.regs[0] = SIP_RNG_64;

        if (bytes <= 4)
                param1 = 0;
        else
                param1 = 1;
        regs.regs[1] = param1;

        smc_call(&regs);

        if (regs.regs[0])
                return -1;

        num = regs.regs[1];
        memcpy(rand, &num, bytes);

        return 0;
}

/*
 * sec_firmware_init - Initialize the SEC Firmware
 * @sec_firmware_img:   the SEC Firmware image address
 * @eret_hold_l:        the address to hold exception return address low
 * @eret_hold_h:        the address to hold exception return address high
 * @loadable_l:         the address to hold loadable address low
 * @loadable_h:         the address to hold loadable address high
 */
int sec_firmware_init(const void *sec_firmware_img,
                        u32 *eret_hold_l,
                        u32 *eret_hold_h,
                        u32 *loadable_l,
                        u32 *loadable_h)
{
        int ret;

        if (!sec_firmware_is_valid(sec_firmware_img))
                return -EINVAL;

        ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
                                      loadable_h);
        if (ret) {
                printf("SEC Firmware: Failed to load image\n");
                return ret;
        } else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
                ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
                if (ret) {
                        printf("SEC Firmware: Failed to initialize\n");
                        return ret;
                }
        }

        debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
              current_el());

        /*
         * The PE will be turned into target EL when returned from
         * SEC Firmware.
         */
        if (current_el() != SEC_FIRMWARE_TARGET_EL)
                return -EACCES;

        sec_firmware_addr |= SEC_FIRMWARE_RUNNING;

        /* Set exception table and enable caches if it isn't EL3 */
        if (current_el() != 3) {
                c_runtime_cpu_setup();
                enable_caches();
        }

        return 0;
}

/*
 * fdt_fix_kaslr - Add kalsr-seed node in Device tree
 * @fdt:                Device tree
 * @eret:               0 in case of error, 1 for success
 */
int fdt_fixup_kaslr(void *fdt)
{
        int nodeoffset;
        int err, ret = 0;
        u8 rand[8];

#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
        /* Check if random seed generation is  supported */
        if (sec_firmware_support_hwrng() == false)
                return 0;

        ret = sec_firmware_get_random(rand, 8);
        if (ret < 0) {
                printf("WARNING: No random number to set kaslr-seed\n");
                return 0;
        }

        err = fdt_check_header(fdt);
        if (err < 0) {
                printf("fdt_chosen: %s\n", fdt_strerror(err));
                return 0;
        }

        /* find or create "/chosen" node. */
        nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
        if (nodeoffset < 0)
                return 0;

        err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
                                  sizeof(rand));
        if (err < 0) {
                printf("WARNING: can't set kaslr-seed %s.\n",
                       fdt_strerror(err));
                return 0;
        }
        ret = 1;
#endif

        return ret;
}