/*
 *
 * Common security related functions for OMAP devices
 *
 * (C) Copyright 2016-2017
 * Texas Instruments, <www.ti.com>
 *
 * Daniel Allred <d-allred@ti.com>
 * Andreas Dannenberg <dannenberg@ti.com>
 * Harinarayan Bhatta <harinarayan@ti.com>
 * Andrew F. Davis <afd@ti.com>
 *
 * SPDX-License-Identifier: GPL-2.0+
 */

#include <common.h>
#include <stdarg.h>

#include <asm/arch/sys_proto.h>
#include <asm/cache.h>
#include <asm/omap_common.h>
#include <asm/omap_sec_common.h>
#include <asm/spl.h>
#include <asm/ti-common/sys_proto.h>
#include <mapmem.h>
#include <spl.h>
#include <tee/optee.h>

/* Index for signature verify ROM API */
#ifdef CONFIG_AM33XX
#define API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX     (0x0000000C)
#else
#define API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX     (0x0000000E)
#endif

/* Index for signature PPA-based TI HAL APIs */
#define PPA_HAL_SERVICES_START_INDEX        (0x200)
#define PPA_SERV_HAL_TEE_LOAD_MASTER        (PPA_HAL_SERVICES_START_INDEX + 23)
#define PPA_SERV_HAL_TEE_LOAD_SLAVE         (PPA_HAL_SERVICES_START_INDEX + 24)
#define PPA_SERV_HAL_SETUP_SEC_RESVD_REGION (PPA_HAL_SERVICES_START_INDEX + 25)
#define PPA_SERV_HAL_SETUP_EMIF_FW_REGION   (PPA_HAL_SERVICES_START_INDEX + 26)
#define PPA_SERV_HAL_LOCK_EMIF_FW           (PPA_HAL_SERVICES_START_INDEX + 27)

/* Offset of header size if image is signed as ISW */
#define HEADER_SIZE_OFFSET      (0x6D)

int tee_loaded = 0;

/* Argument for PPA_SERV_HAL_TEE_LOAD_MASTER */
struct ppa_tee_load_info {
        u32 tee_sec_mem_start; /* Physical start address reserved for TEE */
        u32 tee_sec_mem_size;  /* Size of the memory reserved for TEE */
        u32 tee_cert_start;    /* Address where signed TEE binary is loaded */
        u32 tee_cert_size;     /* Size of TEE certificate (signed binary) */
        u32 tee_jump_addr;     /* Address to jump to start TEE execution */
        u32 tee_arg0;          /* argument to TEE jump function, in r0 */
};

static uint32_t secure_rom_call_args[5] __aligned(ARCH_DMA_MINALIGN);

u32 secure_rom_call(u32 service, u32 proc_id, u32 flag, ...)
{
        int i;
        u32 num_args;
        va_list ap;

        va_start(ap, flag);

        num_args = va_arg(ap, u32);

        if (num_args > 4) {
                va_end(ap);
                return 1;
        }

        /* Copy args to aligned args structure */
        for (i = 0; i < num_args; i++)
                secure_rom_call_args[i + 1] = va_arg(ap, u32);

        secure_rom_call_args[0] = num_args;

        va_end(ap);

        /* if data cache is enabled, flush the aligned args structure */
        flush_dcache_range(
                (unsigned int)&secure_rom_call_args[0],
                (unsigned int)&secure_rom_call_args[0] +
                roundup(sizeof(secure_rom_call_args), ARCH_DMA_MINALIGN));

        return omap_smc_sec(service, proc_id, flag, secure_rom_call_args);
}

static u32 find_sig_start(char *image, size_t size)
{
        char *image_end = image + size;
        char *sig_start_magic = "CERT_";
        int magic_str_len = strlen(sig_start_magic);
        char *ch;

        while (--image_end > image) {
                if (*image_end == '_') {
                        ch = image_end - magic_str_len + 1;
                        if (!strncmp(ch, sig_start_magic, magic_str_len))
                                return (u32)ch;
                }
        }
        return 0;
}

int secure_boot_verify_image(void **image, size_t *size)
{
        int result = 1;
        u32 cert_addr, sig_addr;
        size_t cert_size;

        /* Perform cache writeback on input buffer */
        flush_dcache_range(
                rounddown((u32)*image, ARCH_DMA_MINALIGN),
                roundup((u32)*image + *size, ARCH_DMA_MINALIGN));

        cert_addr = (uint32_t)*image;
        sig_addr = find_sig_start((char *)*image, *size);

        if (sig_addr == 0) {
                printf("No signature found in image!\n");
                result = 1;
                goto auth_exit;
        }

        *size = sig_addr - cert_addr;   /* Subtract out the signature size */
        /* Subtract header if present */
        if (strncmp((char *)sig_addr, "CERT_ISW_", 9) == 0)
                *size = ((u32 *)*image)[HEADER_SIZE_OFFSET];
        cert_size = *size;

        /* Check if image load address is 32-bit aligned */
        if (!IS_ALIGNED(cert_addr, 4)) {
                printf("Image is not 4-byte aligned!\n");
                result = 1;
                goto auth_exit;
        }

        /* Image size also should be multiple of 4 */
        if (!IS_ALIGNED(cert_size, 4)) {
                printf("Image size is not 4-byte aligned!\n");
                result = 1;
                goto auth_exit;
        }

        /* Call ROM HAL API to verify certificate signature */
        debug("%s: load_addr = %x, size = %x, sig_addr = %x\n", __func__,
              cert_addr, cert_size, sig_addr);

        result = secure_rom_call(
                API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX, 0, 0,
                4, cert_addr, cert_size, sig_addr, 0xFFFFFFFF);

        /* Perform cache writeback on output buffer */
        flush_dcache_range(
                rounddown((u32)*image, ARCH_DMA_MINALIGN),
                roundup((u32)*image + *size, ARCH_DMA_MINALIGN));

auth_exit:
        if (result != 0) {
                printf("Authentication failed!\n");
                printf("Return Value = %08X\n", result);
                hang();
        }

        /*
         * Output notification of successful authentication as well the name of
         * the signing certificate used to re-assure the user that the secure
         * code is being processed as expected. However suppress any such log
         * output in case of building for SPL and booting via YMODEM. This is
         * done to avoid disturbing the YMODEM serial protocol transactions.
         */
        if (!(IS_ENABLED(CONFIG_SPL_BUILD) &&
              IS_ENABLED(CONFIG_SPL_YMODEM_SUPPORT) &&
              spl_boot_device() == BOOT_DEVICE_UART))
                printf("Authentication passed: %s\n", (char *)sig_addr);

        return result;
}

u32 get_sec_mem_start(void)
{
        u32 sec_mem_start = CONFIG_TI_SECURE_EMIF_REGION_START;
        u32 sec_mem_size = CONFIG_TI_SECURE_EMIF_TOTAL_REGION_SIZE;
        /*
         * Total reserved region is all contiguous with protected
         * region coming first, followed by the non-secure region.
         * If 0x0 start address is given, we simply put the reserved
         * region at the end of the external DRAM.
         */
        if (sec_mem_start == 0)
                sec_mem_start =
                        (CONFIG_SYS_SDRAM_BASE + (
#if defined(CONFIG_OMAP54XX)
                        omap_sdram_size()
#else
                        get_ram_size((void *)CONFIG_SYS_SDRAM_BASE,
                                     CONFIG_MAX_RAM_BANK_SIZE)
#endif
                        - sec_mem_size));
        return sec_mem_start;
}

int secure_emif_firewall_setup(uint8_t region_num, uint32_t start_addr,
                               uint32_t size, uint32_t access_perm,
                               uint32_t initiator_perm)
{
        int result = 1;

        /*
         * Call PPA HAL API to do any other general firewall
         * configuration for regions 1-6 of the EMIF firewall.
         */
        debug("%s: regionNum = %x, startAddr = %x, size = %x", __func__,
              region_num, start_addr, size);

        result = secure_rom_call(
                        PPA_SERV_HAL_SETUP_EMIF_FW_REGION, 0, 0, 4,
                        (start_addr & 0xFFFFFFF0) | (region_num & 0x0F),
                        size, access_perm, initiator_perm);

        if (result != 0) {
                puts("Secure EMIF Firewall Setup failed!\n");
                debug("Return Value = %x\n", result);
        }

        return result;
}

#if     (CONFIG_TI_SECURE_EMIF_TOTAL_REGION_SIZE <  \
        CONFIG_TI_SECURE_EMIF_PROTECTED_REGION_SIZE)
#error  "TI Secure EMIF: Protected size cannot be larger than total size."
#endif
int secure_emif_reserve(void)
{
        int result = 1;
        u32 sec_mem_start = get_sec_mem_start();
        u32 sec_prot_size = CONFIG_TI_SECURE_EMIF_PROTECTED_REGION_SIZE;

        /* If there is no protected region, there is no reservation to make */
        if (sec_prot_size == 0)
                return 0;

        /*
         * Call PPA HAL API to reserve a chunk of EMIF SDRAM
         * for secure world use. This region should be carved out
         * from use by any public code. EMIF firewall region 7
         * will be used to protect this block of memory.
         */
        result = secure_rom_call(
                        PPA_SERV_HAL_SETUP_SEC_RESVD_REGION,
                        0, 0, 2, sec_mem_start, sec_prot_size);

        if (result != 0) {
                puts("SDRAM Firewall: Secure memory reservation failed!\n");
                debug("Return Value = %x\n", result);
        }

        return result;
}

int secure_emif_firewall_lock(void)
{
        int result = 1;

        /*
         * Call PPA HAL API to lock the EMIF firewall configurations.
         * After this API is called, none of the PPA HAL APIs for
         * configuring the EMIF firewalls will be usable again (that
         * is, calls to those APIs will return failure and have no
         * effect).
         */

        result = secure_rom_call(
                        PPA_SERV_HAL_LOCK_EMIF_FW,
                        0, 0, 0);

        if (result != 0) {
                puts("Secure EMIF Firewall Lock failed!\n");
                debug("Return Value = %x\n", result);
        }

        return result;
}

static struct ppa_tee_load_info tee_info __aligned(ARCH_DMA_MINALIGN);

int secure_tee_install(u32 addr)
{
        struct optee_header *hdr;
        void *loadptr;
        u32 tee_file_size;
        u32 sec_mem_start = get_sec_mem_start();
        const u32 size = CONFIG_TI_SECURE_EMIF_PROTECTED_REGION_SIZE;
        u32 ret;

        /* If there is no protected region, there is no place to put the TEE */
        if (size == 0) {
                printf("Error loading TEE, no protected memory region available\n");
                return -ENOBUFS;
        }

        hdr = (struct optee_header *)map_sysmem(addr, sizeof(struct optee_header));
        /* 280 bytes = size of signature */
        tee_file_size = hdr->init_size + hdr->paged_size +
                        sizeof(struct optee_header) + 280;

        if ((hdr->magic != OPTEE_MAGIC) ||
            (hdr->version != OPTEE_VERSION) ||
            (tee_file_size > size)) {
                printf("Error in TEE header. Check firewall and TEE sizes\n");
                unmap_sysmem(hdr);
                return CMD_RET_FAILURE;
        }

        tee_info.tee_sec_mem_start = sec_mem_start;
        tee_info.tee_sec_mem_size = size;
        tee_info.tee_jump_addr = hdr->init_load_addr_lo;
        tee_info.tee_cert_start = addr;
        tee_info.tee_cert_size = tee_file_size;
        tee_info.tee_arg0 = hdr->init_size + tee_info.tee_jump_addr;
        unmap_sysmem(hdr);
        loadptr = map_sysmem(addr, tee_file_size);

        debug("tee_info.tee_sec_mem_start= %08X\n", tee_info.tee_sec_mem_start);
        debug("tee_info.tee_sec_mem_size = %08X\n", tee_info.tee_sec_mem_size);
        debug("tee_info.tee_jump_addr = %08X\n", tee_info.tee_jump_addr);
        debug("tee_info.tee_cert_start = %08X\n", tee_info.tee_cert_start);
        debug("tee_info.tee_cert_size = %08X\n", tee_info.tee_cert_size);
        debug("tee_info.tee_arg0 = %08X\n", tee_info.tee_arg0);
        debug("tee_file_size = %d\n", tee_file_size);

#if !defined(CONFIG_SYS_DCACHE_OFF)
        flush_dcache_range(
                rounddown((u32)loadptr, ARCH_DMA_MINALIGN),
                roundup((u32)loadptr + tee_file_size, ARCH_DMA_MINALIGN));

        flush_dcache_range((u32)&tee_info, (u32)&tee_info +
                        roundup(sizeof(tee_info), ARCH_DMA_MINALIGN));
#endif
        unmap_sysmem(loadptr);

        ret = secure_rom_call(PPA_SERV_HAL_TEE_LOAD_MASTER, 0, 0, 1, &tee_info);
        if (ret) {
                printf("TEE_LOAD_MASTER Failed\n");
                return ret;
        }
        printf("TEE_LOAD_MASTER Done\n");

#if defined(CONFIG_OMAP54XX)
        if (!is_dra72x()) {
                u32 *smc_cpu1_params;
                /* Reuse the tee_info buffer for SMC params */
                smc_cpu1_params = (u32 *)&tee_info;
                smc_cpu1_params[0] = 0;
#if !defined(CONFIG_SYS_DCACHE_OFF)
                flush_dcache_range((u32)smc_cpu1_params, (u32)smc_cpu1_params +
                                roundup(sizeof(u32), ARCH_DMA_MINALIGN));
#endif
                ret = omap_smc_sec_cpu1(PPA_SERV_HAL_TEE_LOAD_SLAVE, 0, 0,
                                smc_cpu1_params);
                if (ret) {
                        printf("TEE_LOAD_SLAVE Failed\n");
                        return ret;
                }
                printf("TEE_LOAD_SLAVE Done\n");
        }
#endif

        tee_loaded = 1;

        return 0;
}