// SPDX-License-Identifier: GPL-2.0-only
/*
 * SBI initialilization and all extension implementation.
 *
 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
 */

#include <linux/bits.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/pm.h>
#include <linux/reboot.h>
#include <asm/sbi.h>
#include <asm/smp.h>
#include <asm/tlbflush.h>

/* default SBI version is 0.1 */
unsigned long sbi_spec_version __ro_after_init = SBI_SPEC_VERSION_DEFAULT;
EXPORT_SYMBOL(sbi_spec_version);

static void (*__sbi_set_timer)(uint64_t stime) __ro_after_init;
static void (*__sbi_send_ipi)(unsigned int cpu) __ro_after_init;
static int (*__sbi_rfence)(int fid, const struct cpumask *cpu_mask,
                           unsigned long start, unsigned long size,
                           unsigned long arg4, unsigned long arg5) __ro_after_init;

#ifdef CONFIG_RISCV_SBI_V01
static unsigned long __sbi_v01_cpumask_to_hartmask(const struct cpumask *cpu_mask)
{
        unsigned long cpuid, hartid;
        unsigned long hmask = 0;

        /*
         * There is no maximum hartid concept in RISC-V and NR_CPUS must not be
         * associated with hartid. As SBI v0.1 is only kept for backward compatibility
         * and will be removed in the future, there is no point in supporting hartid
         * greater than BITS_PER_LONG (32 for RV32 and 64 for RV64). Ideally, SBI v0.2
         * should be used for platforms with hartid greater than BITS_PER_LONG.
         */
        for_each_cpu(cpuid, cpu_mask) {
                hartid = cpuid_to_hartid_map(cpuid);
                if (hartid >= BITS_PER_LONG) {
                        pr_warn("Unable to send any request to hartid > BITS_PER_LONG for SBI v0.1\n");
                        break;
                }
                hmask |= BIT(hartid);
        }

        return hmask;
}

/**
 * sbi_console_putchar() - Writes given character to the console device.
 * @ch: The data to be written to the console.
 *
 * Return: None
 */
void sbi_console_putchar(int ch)
{
        sbi_ecall(SBI_EXT_0_1_CONSOLE_PUTCHAR, 0, ch, 0, 0, 0, 0, 0);
}
EXPORT_SYMBOL(sbi_console_putchar);

/**
 * sbi_console_getchar() - Reads a byte from console device.
 *
 * Returns the value read from console.
 */
int sbi_console_getchar(void)
{
        struct sbiret ret;

        ret = sbi_ecall(SBI_EXT_0_1_CONSOLE_GETCHAR, 0, 0, 0, 0, 0, 0, 0);

        return ret.error;
}
EXPORT_SYMBOL(sbi_console_getchar);

/**
 * sbi_shutdown() - Remove all the harts from executing supervisor code.
 *
 * Return: None
 */
void sbi_shutdown(void)
{
        sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
}
EXPORT_SYMBOL(sbi_shutdown);

/**
 * __sbi_set_timer_v01() - Program the timer for next timer event.
 * @stime_value: The value after which next timer event should fire.
 *
 * Return: None
 */
static void __sbi_set_timer_v01(uint64_t stime_value)
{
#if __riscv_xlen == 32
        sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value,
                  stime_value >> 32, 0, 0, 0, 0);
#else
        sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value, 0, 0, 0, 0, 0);
#endif
}

static void __sbi_send_ipi_v01(unsigned int cpu)
{
        unsigned long hart_mask =
                __sbi_v01_cpumask_to_hartmask(cpumask_of(cpu));
        sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)(&hart_mask),
                  0, 0, 0, 0, 0);
}

static int __sbi_rfence_v01(int fid, const struct cpumask *cpu_mask,
                            unsigned long start, unsigned long size,
                            unsigned long arg4, unsigned long arg5)
{
        int result = 0;
        unsigned long hart_mask;

        if (!cpu_mask || cpumask_empty(cpu_mask))
                cpu_mask = cpu_online_mask;
        hart_mask = __sbi_v01_cpumask_to_hartmask(cpu_mask);

        /* v0.2 function IDs are equivalent to v0.1 extension IDs */
        switch (fid) {
        case SBI_EXT_RFENCE_REMOTE_FENCE_I:
                sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0,
                          (unsigned long)&hart_mask, 0, 0, 0, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
                sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
                          (unsigned long)&hart_mask, start, size,
                          0, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
                sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
                          (unsigned long)&hart_mask, start, size,
                          arg4, 0, 0);
                break;
        default:
                pr_err("SBI call [%d]not supported in SBI v0.1\n", fid);
                result = -EINVAL;
        }

        return result;
}

static void sbi_set_power_off(void)
{
        register_platform_power_off(sbi_shutdown);
}
#else
static void __sbi_set_timer_v01(uint64_t stime_value)
{
        pr_warn("Timer extension is not available in SBI v%lu.%lu\n",
                sbi_major_version(), sbi_minor_version());
}

static void __sbi_send_ipi_v01(unsigned int cpu)
{
        pr_warn("IPI extension is not available in SBI v%lu.%lu\n",
                sbi_major_version(), sbi_minor_version());
}

static int __sbi_rfence_v01(int fid, const struct cpumask *cpu_mask,
                            unsigned long start, unsigned long size,
                            unsigned long arg4, unsigned long arg5)
{
        pr_warn("remote fence extension is not available in SBI v%lu.%lu\n",
                sbi_major_version(), sbi_minor_version());

        return 0;
}

static void sbi_set_power_off(void) {}
#endif /* CONFIG_RISCV_SBI_V01 */

static void __sbi_set_timer_v02(uint64_t stime_value)
{
#if __riscv_xlen == 32
        sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
                  stime_value >> 32, 0, 0, 0, 0);
#else
        sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0,
                  0, 0, 0, 0);
#endif
}

static void __sbi_send_ipi_v02(unsigned int cpu)
{
        int result;
        struct sbiret ret = {0};

        ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
                        1UL, cpuid_to_hartid_map(cpu), 0, 0, 0, 0);
        if (ret.error) {
                result = sbi_err_map_linux_errno(ret.error);
                pr_err("%s: hbase = [%lu] failed (error [%d])\n",
                        __func__, cpuid_to_hartid_map(cpu), result);
        }
}

static int __sbi_rfence_v02_call(unsigned long fid, unsigned long hmask,
                                 unsigned long hbase, unsigned long start,
                                 unsigned long size, unsigned long arg4,
                                 unsigned long arg5)
{
        struct sbiret ret = {0};
        int ext = SBI_EXT_RFENCE;
        int result = 0;

        switch (fid) {
        case SBI_EXT_RFENCE_REMOTE_FENCE_I:
                ret = sbi_ecall(ext, fid, hmask, hbase, 0, 0, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, arg4, 0);
                break;

        case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, arg4, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, 0, 0);
                break;
        case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
                ret = sbi_ecall(ext, fid, hmask, hbase, start,
                                size, arg4, 0);
                break;
        default:
                pr_err("unknown function ID [%lu] for SBI extension [%d]\n",
                       fid, ext);
                result = -EINVAL;
        }

        if (ret.error) {
                result = sbi_err_map_linux_errno(ret.error);
                pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
                       __func__, hbase, hmask, result);
        }

        return result;
}

static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask,
                            unsigned long start, unsigned long size,
                            unsigned long arg4, unsigned long arg5)
{
        unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0;
        int result;

        if (!cpu_mask || cpumask_empty(cpu_mask))
                cpu_mask = cpu_online_mask;

        for_each_cpu(cpuid, cpu_mask) {
                hartid = cpuid_to_hartid_map(cpuid);
                if (hmask) {
                        if (hartid + BITS_PER_LONG <= htop ||
                            hbase + BITS_PER_LONG <= hartid) {
                                result = __sbi_rfence_v02_call(fid, hmask,
                                                hbase, start, size, arg4, arg5);
                                if (result)
                                        return result;
                                hmask = 0;
                        } else if (hartid < hbase) {
                                /* shift the mask to fit lower hartid */
                                hmask <<= hbase - hartid;
                                hbase = hartid;
                        }
                }
                if (!hmask) {
                        hbase = hartid;
                        htop = hartid;
                } else if (hartid > htop) {
                        htop = hartid;
                }
                hmask |= BIT(hartid - hbase);
        }

        if (hmask) {
                result = __sbi_rfence_v02_call(fid, hmask, hbase,
                                               start, size, arg4, arg5);
                if (result)
                        return result;
        }

        return 0;
}

static bool sbi_fwft_supported;

struct fwft_set_req {
        u32 feature;
        unsigned long value;
        unsigned long flags;
        atomic_t error;
};

static void cpu_sbi_fwft_set(void *arg)
{
        struct fwft_set_req *req = arg;
        int ret;

        ret = sbi_fwft_set(req->feature, req->value, req->flags);
        if (ret)
                atomic_set(&req->error, ret);
}

/**
 * sbi_fwft_set() - Set a feature on the local hart
 * @feature: The feature ID to be set
 * @value: The feature value to be set
 * @flags: FWFT feature set flags
 *
 * Return: 0 on success, appropriate linux error code otherwise.
 */
int sbi_fwft_set(u32 feature, unsigned long value, unsigned long flags)
{
        struct sbiret ret;

        if (!sbi_fwft_supported)
                return -EOPNOTSUPP;

        ret = sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET,
                        feature, value, flags, 0, 0, 0);

        return sbi_err_map_linux_errno(ret.error);
}

/**
 * sbi_fwft_set_cpumask() - Set a feature for the specified cpumask
 * @mask: CPU mask of cpus that need the feature to be set
 * @feature: The feature ID to be set
 * @value: The feature value to be set
 * @flags: FWFT feature set flags
 *
 * Return: 0 on success, appropriate linux error code otherwise.
 */
int sbi_fwft_set_cpumask(const cpumask_t *mask, u32 feature,
                               unsigned long value, unsigned long flags)
{
        struct fwft_set_req req = {
                .feature = feature,
                .value = value,
                .flags = flags,
                .error = ATOMIC_INIT(0),
        };

        if (!sbi_fwft_supported)
                return -EOPNOTSUPP;

        if (feature & SBI_FWFT_GLOBAL_FEATURE_BIT)
                return -EINVAL;

        on_each_cpu_mask(mask, cpu_sbi_fwft_set, &req, 1);

        return atomic_read(&req.error);
}

/**
 * sbi_set_timer() - Program the timer for next timer event.
 * @stime_value: The value after which next timer event should fire.
 *
 * Return: None.
 */
void sbi_set_timer(uint64_t stime_value)
{
        __sbi_set_timer(stime_value);
}

/**
 * sbi_send_ipi() - Send an IPI to any hart.
 * @cpu: Logical id of the target CPU.
 */
void sbi_send_ipi(unsigned int cpu)
{
        __sbi_send_ipi(cpu);
}
EXPORT_SYMBOL(sbi_send_ipi);

/**
 * sbi_remote_fence_i() - Execute FENCE.I instruction on given remote harts.
 * @cpu_mask: A cpu mask containing all the target harts.
 *
 * Return: 0 on success, appropriate linux error code otherwise.
 */
int sbi_remote_fence_i(const struct cpumask *cpu_mask)
{
        return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_FENCE_I,
                            cpu_mask, 0, 0, 0, 0);
}
EXPORT_SYMBOL(sbi_remote_fence_i);

/**
 * sbi_remote_sfence_vma_asid() - Execute SFENCE.VMA instructions on given
 * remote harts for a virtual address range belonging to a specific ASID or not.
 *
 * @cpu_mask: A cpu mask containing all the target harts.
 * @start: Start of the virtual address
 * @size: Total size of the virtual address range.
 * @asid: The value of address space identifier (ASID), or FLUSH_TLB_NO_ASID
 * for flushing all address spaces.
 *
 * Return: 0 on success, appropriate linux error code otherwise.
 */
int sbi_remote_sfence_vma_asid(const struct cpumask *cpu_mask,
                                unsigned long start,
                                unsigned long size,
                                unsigned long asid)
{
        if (asid == FLUSH_TLB_NO_ASID)
                return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA,
                                    cpu_mask, start, size, 0, 0);
        else
                return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID,
                                    cpu_mask, start, size, asid, 0);
}
EXPORT_SYMBOL(sbi_remote_sfence_vma_asid);

/**
 * sbi_remote_hfence_gvma() - Execute HFENCE.GVMA instructions on given remote
 *                         harts for the specified guest physical address range.
 * @cpu_mask: A cpu mask containing all the target harts.
 * @start: Start of the guest physical address
 * @size: Total size of the guest physical address range.
 *
 * Return: None
 */
int sbi_remote_hfence_gvma(const struct cpumask *cpu_mask,
                           unsigned long start,
                           unsigned long size)
{
        return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA,
                            cpu_mask, start, size, 0, 0);
}
EXPORT_SYMBOL_GPL(sbi_remote_hfence_gvma);

/**
 * sbi_remote_hfence_gvma_vmid() - Execute HFENCE.GVMA instructions on given
 * remote harts for a guest physical address range belonging to a specific VMID.
 *
 * @cpu_mask: A cpu mask containing all the target harts.
 * @start: Start of the guest physical address
 * @size: Total size of the guest physical address range.
 * @vmid: The value of guest ID (VMID).
 *
 * Return: 0 if success, Error otherwise.
 */
int sbi_remote_hfence_gvma_vmid(const struct cpumask *cpu_mask,
                                unsigned long start,
                                unsigned long size,
                                unsigned long vmid)
{
        return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID,
                            cpu_mask, start, size, vmid, 0);
}
EXPORT_SYMBOL(sbi_remote_hfence_gvma_vmid);

/**
 * sbi_remote_hfence_vvma() - Execute HFENCE.VVMA instructions on given remote
 *                           harts for the current guest virtual address range.
 * @cpu_mask: A cpu mask containing all the target harts.
 * @start: Start of the current guest virtual address
 * @size: Total size of the current guest virtual address range.
 *
 * Return: None
 */
int sbi_remote_hfence_vvma(const struct cpumask *cpu_mask,
                           unsigned long start,
                           unsigned long size)
{
        return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA,
                            cpu_mask, start, size, 0, 0);
}
EXPORT_SYMBOL(sbi_remote_hfence_vvma);

/**
 * sbi_remote_hfence_vvma_asid() - Execute HFENCE.VVMA instructions on given
 * remote harts for current guest virtual address range belonging to a specific
 * ASID.
 *
 * @cpu_mask: A cpu mask containing all the target harts.
 * @start: Start of the current guest virtual address
 * @size: Total size of the current guest virtual address range.
 * @asid: The value of address space identifier (ASID).
 *
 * Return: None
 */
int sbi_remote_hfence_vvma_asid(const struct cpumask *cpu_mask,
                                unsigned long start,
                                unsigned long size,
                                unsigned long asid)
{
        return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID,
                            cpu_mask, start, size, asid, 0);
}
EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid);

static void sbi_srst_reset(unsigned long type, unsigned long reason)
{
        sbi_ecall(SBI_EXT_SRST, SBI_EXT_SRST_RESET, type, reason,
                  0, 0, 0, 0);
        pr_warn("%s: type=0x%lx reason=0x%lx failed\n",
                __func__, type, reason);
}

static int sbi_srst_reboot(struct notifier_block *this,
                           unsigned long mode, void *cmd)
{
        sbi_srst_reset((mode == REBOOT_WARM || mode == REBOOT_SOFT) ?
                       SBI_SRST_RESET_TYPE_WARM_REBOOT :
                       SBI_SRST_RESET_TYPE_COLD_REBOOT,
                       SBI_SRST_RESET_REASON_NONE);
        return NOTIFY_DONE;
}

static struct notifier_block sbi_srst_reboot_nb;

static void sbi_srst_power_off(void)
{
        sbi_srst_reset(SBI_SRST_RESET_TYPE_SHUTDOWN,
                       SBI_SRST_RESET_REASON_NONE);
}

/**
 * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
 * @extid: The extension ID to be probed.
 *
 * Return: 1 or an extension specific nonzero value if yes, 0 otherwise.
 */
long sbi_probe_extension(int extid)
{
        struct sbiret ret;

        ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid,
                        0, 0, 0, 0, 0);
        if (!ret.error)
                return ret.value;

        return 0;
}
EXPORT_SYMBOL(sbi_probe_extension);

static inline long sbi_get_spec_version(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);
}

static inline long sbi_get_firmware_id(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_ID);
}

static inline long sbi_get_firmware_version(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_VERSION);
}

long sbi_get_mvendorid(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
}
EXPORT_SYMBOL_GPL(sbi_get_mvendorid);

long sbi_get_marchid(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
}
EXPORT_SYMBOL_GPL(sbi_get_marchid);

long sbi_get_mimpid(void)
{
        return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
}
EXPORT_SYMBOL_GPL(sbi_get_mimpid);

bool sbi_debug_console_available;

int sbi_debug_console_write(const char *bytes, unsigned int num_bytes)
{
        phys_addr_t base_addr;
        struct sbiret ret;

        if (!sbi_debug_console_available)
                return -EOPNOTSUPP;

        if (is_vmalloc_addr(bytes))
                base_addr = page_to_phys(vmalloc_to_page(bytes)) +
                            offset_in_page(bytes);
        else
                base_addr = __pa(bytes);
        if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
                num_bytes = PAGE_SIZE - offset_in_page(bytes);

        if (IS_ENABLED(CONFIG_32BIT))
                ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
                                num_bytes, lower_32_bits(base_addr),
                                upper_32_bits(base_addr), 0, 0, 0);
        else
                ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
                                num_bytes, base_addr, 0, 0, 0, 0);

        if (ret.error == SBI_ERR_FAILURE)
                return -EIO;
        return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value;
}

int sbi_debug_console_read(char *bytes, unsigned int num_bytes)
{
        phys_addr_t base_addr;
        struct sbiret ret;

        if (!sbi_debug_console_available)
                return -EOPNOTSUPP;

        if (is_vmalloc_addr(bytes))
                base_addr = page_to_phys(vmalloc_to_page(bytes)) +
                            offset_in_page(bytes);
        else
                base_addr = __pa(bytes);
        if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
                num_bytes = PAGE_SIZE - offset_in_page(bytes);

        if (IS_ENABLED(CONFIG_32BIT))
                ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
                                num_bytes, lower_32_bits(base_addr),
                                upper_32_bits(base_addr), 0, 0, 0);
        else
                ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
                                num_bytes, base_addr, 0, 0, 0, 0);

        if (ret.error == SBI_ERR_FAILURE)
                return -EIO;
        return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value;
}

void __init sbi_init(void)
{
        bool srst_power_off = false;
        int ret;

        ret = sbi_get_spec_version();
        if (ret > 0)
                sbi_spec_version = ret;

        pr_info("SBI specification v%lu.%lu detected\n",
                sbi_major_version(), sbi_minor_version());

        if (!sbi_spec_is_0_1()) {
                pr_info("SBI implementation ID=0x%lx Version=0x%lx\n",
                        sbi_get_firmware_id(), sbi_get_firmware_version());
                if (sbi_probe_extension(SBI_EXT_TIME)) {
                        __sbi_set_timer = __sbi_set_timer_v02;
                        pr_info("SBI TIME extension detected\n");
                } else {
                        __sbi_set_timer = __sbi_set_timer_v01;
                }
                if (sbi_probe_extension(SBI_EXT_IPI)) {
                        __sbi_send_ipi  = __sbi_send_ipi_v02;
                        pr_info("SBI IPI extension detected\n");
                } else {
                        __sbi_send_ipi  = __sbi_send_ipi_v01;
                }
                if (sbi_probe_extension(SBI_EXT_RFENCE)) {
                        __sbi_rfence    = __sbi_rfence_v02;
                        pr_info("SBI RFENCE extension detected\n");
                } else {
                        __sbi_rfence    = __sbi_rfence_v01;
                }
                if (sbi_spec_version >= sbi_mk_version(0, 3) &&
                    sbi_probe_extension(SBI_EXT_SRST)) {
                        pr_info("SBI SRST extension detected\n");
                        register_platform_power_off(sbi_srst_power_off);
                        srst_power_off = true;
                        sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot;
                        sbi_srst_reboot_nb.priority = 192;
                        register_restart_handler(&sbi_srst_reboot_nb);
                }
                if (sbi_spec_version >= sbi_mk_version(2, 0) &&
                    sbi_probe_extension(SBI_EXT_DBCN) > 0) {
                        pr_info("SBI DBCN extension detected\n");
                        sbi_debug_console_available = true;
                }
                if (sbi_spec_version >= sbi_mk_version(3, 0) &&
                    sbi_probe_extension(SBI_EXT_FWFT)) {
                        pr_info("SBI FWFT extension detected\n");
                        sbi_fwft_supported = true;
                }
        } else {
                __sbi_set_timer = __sbi_set_timer_v01;
                __sbi_send_ipi  = __sbi_send_ipi_v01;
                __sbi_rfence    = __sbi_rfence_v01;
        }

        if (!srst_power_off)
                sbi_set_power_off();
}