// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 Synopsys, Inc. All rights reserved.
 * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
 */

#include <common.h>
#include <config.h>
#include <env.h>
#include <linux/printk.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <asm/arcregs.h>
#include <fdt_support.h>
#include <dwmmc.h>
#include <malloc.h>
#include <usb.h>

#include "clk-lib.h"
#include "env-lib.h"

DECLARE_GLOBAL_DATA_PTR;

#define ALL_CPU_MASK            GENMASK(NR_CPUS - 1, 0)
#define MASTER_CPU_ID           0
#define APERTURE_SHIFT          28
#define NO_CCM                  0x10
#define SLAVE_CPU_READY         0x12345678
#define BOOTSTAGE_1             1 /* after SP, FP setup, before HW init */
#define BOOTSTAGE_2             2 /* after HW init, before self halt */
#define BOOTSTAGE_3             3 /* after self halt */
#define BOOTSTAGE_4             4 /* before app launch */
#define BOOTSTAGE_5             5 /* after app launch, unreachable */

#define RESET_VECTOR_ADDR       0x0

#define CREG_BASE               (ARC_PERIPHERAL_BASE + 0x1000)
#define CREG_CPU_START          (CREG_BASE + 0x400)
#define CREG_CPU_START_MASK     0xF

#define SDIO_BASE               (ARC_PERIPHERAL_BASE + 0xA000)
#define SDIO_UHS_REG_EXT        (SDIO_BASE + 0x108)
#define SDIO_UHS_REG_EXT_DIV_2  (2 << 30)

/* Uncached access macros */
#define arc_read_uncached_32(ptr)       \
({                                      \
        unsigned int __ret;             \
        __asm__ __volatile__(           \
        "       ld.di %0, [%1]  \n"     \
        : "=r"(__ret)                   \
        : "r"(ptr));                    \
        __ret;                          \
})

#define arc_write_uncached_32(ptr, data)\
({                                      \
        __asm__ __volatile__(           \
        "       st.di %0, [%1]  \n"     \
        :                               \
        : "r"(data), "r"(ptr));         \
})

struct hsdk_env_core_ctl {
        u32_env entry[NR_CPUS];
        u32_env iccm[NR_CPUS];
        u32_env dccm[NR_CPUS];
};

struct hsdk_env_common_ctl {
        bool halt_on_boot;
        u32_env core_mask;
        u32_env cpu_freq;
        u32_env axi_freq;
        u32_env tun_freq;
        u32_env nvlim;
        u32_env icache;
        u32_env dcache;
};

/*
 * Uncached cross-cpu structure. All CPUs must access to this structure fields
 * only with arc_read_uncached_32() / arc_write_uncached_32() accessors (which
 * implement ld.di / st.di instructions). Simultaneous cached and uncached
 * access to this area will lead to data loss.
 * We flush all data caches in board_early_init_r() as we don't want to have
 * any dirty line in L1d$ or SL$ in this area.
 */
struct hsdk_cross_cpu {
        /* slave CPU ready flag */
        u32 ready_flag;
        /* address of the area, which can be used for stack by slave CPU */
        u32 stack_ptr;
        /* slave CPU status - bootstage number */
        s32 status[NR_CPUS];

        /*
         * Slave CPU data - it is copy of corresponding fields in
         * hsdk_env_core_ctl and hsdk_env_common_ctl structures which are
         * required for slave CPUs initialization.
         * This fields can be populated by copying from hsdk_env_core_ctl
         * and hsdk_env_common_ctl structures with sync_cross_cpu_data()
         * function.
         */
        u32 entry[NR_CPUS];
        u32 iccm[NR_CPUS];
        u32 dccm[NR_CPUS];

        u32 core_mask;
        u32 icache;
        u32 dcache;

        u8 cache_padding[ARCH_DMA_MINALIGN];
} __aligned(ARCH_DMA_MINALIGN);

/* Place for slave CPUs temporary stack */
static u32 slave_stack[256 * NR_CPUS] __aligned(ARCH_DMA_MINALIGN);

static struct hsdk_env_common_ctl env_common = {};
static struct hsdk_env_core_ctl env_core = {};
static struct hsdk_cross_cpu cross_cpu_data;

static const struct env_map_common env_map_common[] = {
        { "core_mask",  ENV_HEX, true,  0x1, 0xF,       &env_common.core_mask },
        { "non_volatile_limit", ENV_HEX, true, 0, 0xF,  &env_common.nvlim },
        { "icache_ena", ENV_HEX, true,  0, 1,           &env_common.icache },
        { "dcache_ena", ENV_HEX, true,  0, 1,           &env_common.dcache },
        {}
};

static const struct env_map_common env_map_clock[] = {
        { "cpu_freq",   ENV_DEC, false, 100, 1000,      &env_common.cpu_freq },
        { "axi_freq",   ENV_DEC, false, 200, 800,       &env_common.axi_freq },
        { "tun_freq",   ENV_DEC, false, 0, 150,         &env_common.tun_freq },
        {}
};

static const struct env_map_percpu env_map_core[] = {
        { "core_iccm", ENV_HEX, true, {NO_CCM, 0, NO_CCM, 0}, {NO_CCM, 0xF, NO_CCM, 0xF}, &env_core.iccm },
        { "core_dccm", ENV_HEX, true, {NO_CCM, 0, NO_CCM, 0}, {NO_CCM, 0xF, NO_CCM, 0xF}, &env_core.dccm },
        {}
};

static const struct env_map_common env_map_mask[] = {
        { "core_mask",  ENV_HEX, false, 0x1, 0xF,       &env_common.core_mask },
        {}
};

static const struct env_map_percpu env_map_go[] = {
        { "core_entry", ENV_HEX, true, {0, 0, 0, 0}, {U32_MAX, U32_MAX, U32_MAX, U32_MAX}, &env_core.entry },
        {}
};

static void sync_cross_cpu_data(void)
{
        u32 value;

        for (u32 i = 0; i < NR_CPUS; i++) {
                value = env_core.entry[i].val;
                arc_write_uncached_32(&cross_cpu_data.entry[i], value);
        }

        for (u32 i = 0; i < NR_CPUS; i++) {
                value = env_core.iccm[i].val;
                arc_write_uncached_32(&cross_cpu_data.iccm[i], value);
        }

        for (u32 i = 0; i < NR_CPUS; i++) {
                value = env_core.dccm[i].val;
                arc_write_uncached_32(&cross_cpu_data.dccm[i], value);
        }

        value = env_common.core_mask.val;
        arc_write_uncached_32(&cross_cpu_data.core_mask, value);

        value = env_common.icache.val;
        arc_write_uncached_32(&cross_cpu_data.icache, value);

        value = env_common.dcache.val;
        arc_write_uncached_32(&cross_cpu_data.dcache, value);
}

/* Can be used only on master CPU */
static bool is_cpu_used(u32 cpu_id)
{
        return !!(env_common.core_mask.val & BIT(cpu_id));
}

/* TODO: add ICCM BCR and DCCM BCR runtime check */
static void init_slave_cpu_func(u32 core)
{
        u32 val;

        /* Remap ICCM to another memory region if it exists */
        val = arc_read_uncached_32(&cross_cpu_data.iccm[core]);
        if (val != NO_CCM)
                write_aux_reg(ARC_AUX_ICCM_BASE, val << APERTURE_SHIFT);

        /* Remap DCCM to another memory region if it exists */
        val = arc_read_uncached_32(&cross_cpu_data.dccm[core]);
        if (val != NO_CCM)
                write_aux_reg(ARC_AUX_DCCM_BASE, val << APERTURE_SHIFT);

        if (arc_read_uncached_32(&cross_cpu_data.icache))
                icache_enable();
        else
                icache_disable();

        if (arc_read_uncached_32(&cross_cpu_data.dcache))
                dcache_enable();
        else
                dcache_disable();
}

static void init_cluster_nvlim(void)
{
        u32 val = env_common.nvlim.val << APERTURE_SHIFT;

        flush_dcache_all();
        write_aux_reg(ARC_AUX_NON_VOLATILE_LIMIT, val);
        write_aux_reg(AUX_AUX_CACHE_LIMIT, val);
        flush_n_invalidate_dcache_all();
}

static void init_master_icache(void)
{
        if (icache_status()) {
                /* I$ is enabled - we need to disable it */
                if (!env_common.icache.val)
                        icache_disable();
        } else {
                /* I$ is disabled - we need to enable it */
                if (env_common.icache.val) {
                        icache_enable();

                        /* invalidate I$ right after enable */
                        invalidate_icache_all();
                }
        }
}

static void init_master_dcache(void)
{
        if (dcache_status()) {
                /* D$ is enabled - we need to disable it */
                if (!env_common.dcache.val)
                        dcache_disable();
        } else {
                /* D$ is disabled - we need to enable it */
                if (env_common.dcache.val)
                        dcache_enable();

                /* TODO: probably we need ti invalidate D$ right after enable */
        }
}

static int cleanup_before_go(void)
{
        disable_interrupts();
        sync_n_cleanup_cache_all();

        return 0;
}

void slave_cpu_set_boot_addr(u32 addr)
{
        /* All cores have reset vector pointing to 0 */
        writel(addr, (void __iomem *)RESET_VECTOR_ADDR);

        /* Make sure other cores see written value in memory */
        sync_n_cleanup_cache_all();
}

static inline void halt_this_cpu(void)
{
        __builtin_arc_flag(1);
}

static void smp_kick_cpu_x(u32 cpu_id)
{
        int cmd = readl((void __iomem *)CREG_CPU_START);

        if (cpu_id > NR_CPUS)
                return;

        cmd &= ~CREG_CPU_START_MASK;
        cmd |= (1 << cpu_id);
        writel(cmd, (void __iomem *)CREG_CPU_START);
}

static u32 prepare_cpu_ctart_reg(void)
{
        int cmd = readl((void __iomem *)CREG_CPU_START);

        cmd &= ~CREG_CPU_START_MASK;

        return cmd | env_common.core_mask.val;
}

/* slave CPU entry for configuration */
__attribute__((naked, noreturn, flatten)) noinline void hsdk_core_init_f(void)
{
        __asm__ __volatile__(
                "ld.di  r8,     [%0]\n"
                "mov    %%sp,   r8\n"
                "mov    %%fp,   %%sp\n"
                : /* no output */
                : "r" (&cross_cpu_data.stack_ptr));

        invalidate_icache_all();

        arc_write_uncached_32(&cross_cpu_data.status[CPU_ID_GET()], BOOTSTAGE_1);
        init_slave_cpu_func(CPU_ID_GET());

        arc_write_uncached_32(&cross_cpu_data.ready_flag, SLAVE_CPU_READY);
        arc_write_uncached_32(&cross_cpu_data.status[CPU_ID_GET()], BOOTSTAGE_2);

        /* Halt the processor until the master kick us again */
        halt_this_cpu();

        /*
         * 3 NOPs after FLAG 1 instruction are no longer required for ARCv2
         * cores but we leave them for gebug purposes.
         */
        __builtin_arc_nop();
        __builtin_arc_nop();
        __builtin_arc_nop();

        arc_write_uncached_32(&cross_cpu_data.status[CPU_ID_GET()], BOOTSTAGE_3);

        /* get the updated entry - invalidate i$ */
        invalidate_icache_all();

        arc_write_uncached_32(&cross_cpu_data.status[CPU_ID_GET()], BOOTSTAGE_4);

        /* Run our program */
        ((void (*)(void))(arc_read_uncached_32(&cross_cpu_data.entry[CPU_ID_GET()])))();

        /* This bootstage is unreachable as we don't return from app we launch */
        arc_write_uncached_32(&cross_cpu_data.status[CPU_ID_GET()], BOOTSTAGE_5);

        /* Something went terribly wrong */
        while (true)
                halt_this_cpu();
}

static void clear_cross_cpu_data(void)
{
        arc_write_uncached_32(&cross_cpu_data.ready_flag, 0);
        arc_write_uncached_32(&cross_cpu_data.stack_ptr, 0);

        for (u32 i = 0; i < NR_CPUS; i++)
                arc_write_uncached_32(&cross_cpu_data.status[i], 0);
}

static noinline void do_init_slave_cpu(u32 cpu_id)
{
        /* attempts number for check clave CPU ready_flag */
        u32 attempts = 100;
        u32 stack_ptr = (u32)(slave_stack + (64 * cpu_id));

        if (cpu_id >= NR_CPUS)
                return;

        arc_write_uncached_32(&cross_cpu_data.ready_flag, 0);

        /* Use global unique place for each slave cpu stack */
        arc_write_uncached_32(&cross_cpu_data.stack_ptr, stack_ptr);

        debug("CPU %u: stack pool base: %p\n", cpu_id, slave_stack);
        debug("CPU %u: current slave stack base: %x\n", cpu_id, stack_ptr);
        slave_cpu_set_boot_addr((u32)hsdk_core_init_f);

        smp_kick_cpu_x(cpu_id);

        debug("CPU %u: cross-cpu flag: %x [before timeout]\n", cpu_id,
              arc_read_uncached_32(&cross_cpu_data.ready_flag));

        while (!arc_read_uncached_32(&cross_cpu_data.ready_flag) && attempts--)
                mdelay(10);

        /* Just to be sure that slave cpu is halted after it set ready_flag */
        mdelay(20);

        /*
         * Only print error here if we reach timeout as there is no option to
         * halt slave cpu (or check that slave cpu is halted)
         */
        if (!attempts)
                pr_err("CPU %u is not responding after init!\n", cpu_id);

        /* Check current stage of slave cpu */
        if (arc_read_uncached_32(&cross_cpu_data.status[cpu_id]) != BOOTSTAGE_2)
                pr_err("CPU %u status is unexpected: %d\n", cpu_id,
                       arc_read_uncached_32(&cross_cpu_data.status[cpu_id]));

        debug("CPU %u: cross-cpu flag: %x [after timeout]\n", cpu_id,
              arc_read_uncached_32(&cross_cpu_data.ready_flag));
        debug("CPU %u: status: %d [after timeout]\n", cpu_id,
              arc_read_uncached_32(&cross_cpu_data.status[cpu_id]));
}

static void do_init_slave_cpus(void)
{
        clear_cross_cpu_data();
        sync_cross_cpu_data();

        debug("cross_cpu_data location: %#x\n", (u32)&cross_cpu_data);

        for (u32 i = MASTER_CPU_ID + 1; i < NR_CPUS; i++)
                if (is_cpu_used(i))
                        do_init_slave_cpu(i);
}

static void do_init_master_cpu(void)
{
        /*
         * Setup master caches even if master isn't used as we want to use
         * same cache configuration on all running CPUs
         */
        init_master_icache();
        init_master_dcache();
}

enum hsdk_axi_masters {
        M_HS_CORE = 0,
        M_HS_RTT,
        M_AXI_TUN,
        M_HDMI_VIDEO,
        M_HDMI_AUDIO,
        M_USB_HOST,
        M_ETHERNET,
        M_SDIO,
        M_GPU,
        M_DMAC_0,
        M_DMAC_1,
        M_DVFS
};

#define UPDATE_VAL      1

/*
 * m    master          AXI_M_m_SLV0    AXI_M_m_SLV1    AXI_M_m_OFFSET0 AXI_M_m_OFFSET1
 * 0    HS (CBU)        0x11111111      0x63111111      0xFEDCBA98      0x0E543210
 * 1    HS (RTT)        0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 2    AXI Tunnel      0x88888888      0x88888888      0xFEDCBA98      0x76543210
 * 3    HDMI-VIDEO      0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 4    HDMI-ADUIO      0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 5    USB-HOST        0x77777777      0x77999999      0xFEDCBA98      0x76DCBA98
 * 6    ETHERNET        0x77777777      0x77999999      0xFEDCBA98      0x76DCBA98
 * 7    SDIO            0x77777777      0x77999999      0xFEDCBA98      0x76DCBA98
 * 8    GPU             0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 9    DMAC (port #1)  0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 10   DMAC (port #2)  0x77777777      0x77777777      0xFEDCBA98      0x76543210
 * 11   DVFS            0x00000000      0x60000000      0x00000000      0x00000000
 *
 * Please read ARC HS Development IC Specification, section 17.2 for more
 * information about apertures configuration.
 * NOTE: we intentionally modify default settings in U-boot. Default settings
 * are specified in "Table 111 CREG Address Decoder register reset values".
 */

#define CREG_AXI_M_SLV0(m)  ((void __iomem *)(CREG_BASE + 0x020 * (m)))
#define CREG_AXI_M_SLV1(m)  ((void __iomem *)(CREG_BASE + 0x020 * (m) + 0x004))
#define CREG_AXI_M_OFT0(m)  ((void __iomem *)(CREG_BASE + 0x020 * (m) + 0x008))
#define CREG_AXI_M_OFT1(m)  ((void __iomem *)(CREG_BASE + 0x020 * (m) + 0x00C))
#define CREG_AXI_M_UPDT(m)  ((void __iomem *)(CREG_BASE + 0x020 * (m) + 0x014))

#define CREG_AXI_M_HS_CORE_BOOT ((void __iomem *)(CREG_BASE + 0x010))

#define CREG_PAE        ((void __iomem *)(CREG_BASE + 0x180))
#define CREG_PAE_UPDT   ((void __iomem *)(CREG_BASE + 0x194))

void init_memory_bridge(void)
{
        u32 reg;

        /*
         * M_HS_CORE has one unic register - BOOT.
         * We need to clean boot mirror (BOOT[1:0]) bits in them.
         */
        reg = readl(CREG_AXI_M_HS_CORE_BOOT) & (~0x3);
        writel(reg, CREG_AXI_M_HS_CORE_BOOT);
        writel(0x11111111, CREG_AXI_M_SLV0(M_HS_CORE));
        writel(0x63111111, CREG_AXI_M_SLV1(M_HS_CORE));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_HS_CORE));
        writel(0x0E543210, CREG_AXI_M_OFT1(M_HS_CORE));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_HS_CORE));

        writel(0x77777777, CREG_AXI_M_SLV0(M_HS_RTT));
        writel(0x77777777, CREG_AXI_M_SLV1(M_HS_RTT));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_HS_RTT));
        writel(0x76543210, CREG_AXI_M_OFT1(M_HS_RTT));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_HS_RTT));

        writel(0x88888888, CREG_AXI_M_SLV0(M_AXI_TUN));
        writel(0x88888888, CREG_AXI_M_SLV1(M_AXI_TUN));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_AXI_TUN));
        writel(0x76543210, CREG_AXI_M_OFT1(M_AXI_TUN));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_AXI_TUN));

        writel(0x77777777, CREG_AXI_M_SLV0(M_HDMI_VIDEO));
        writel(0x77777777, CREG_AXI_M_SLV1(M_HDMI_VIDEO));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_HDMI_VIDEO));
        writel(0x76543210, CREG_AXI_M_OFT1(M_HDMI_VIDEO));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_HDMI_VIDEO));

        writel(0x77777777, CREG_AXI_M_SLV0(M_HDMI_AUDIO));
        writel(0x77777777, CREG_AXI_M_SLV1(M_HDMI_AUDIO));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_HDMI_AUDIO));
        writel(0x76543210, CREG_AXI_M_OFT1(M_HDMI_AUDIO));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_HDMI_AUDIO));

        writel(0x77777777, CREG_AXI_M_SLV0(M_USB_HOST));
        writel(0x77999999, CREG_AXI_M_SLV1(M_USB_HOST));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_USB_HOST));
        writel(0x76DCBA98, CREG_AXI_M_OFT1(M_USB_HOST));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_USB_HOST));

        writel(0x77777777, CREG_AXI_M_SLV0(M_ETHERNET));
        writel(0x77999999, CREG_AXI_M_SLV1(M_ETHERNET));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_ETHERNET));
        writel(0x76DCBA98, CREG_AXI_M_OFT1(M_ETHERNET));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_ETHERNET));

        writel(0x77777777, CREG_AXI_M_SLV0(M_SDIO));
        writel(0x77999999, CREG_AXI_M_SLV1(M_SDIO));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_SDIO));
        writel(0x76DCBA98, CREG_AXI_M_OFT1(M_SDIO));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_SDIO));

        writel(0x77777777, CREG_AXI_M_SLV0(M_GPU));
        writel(0x77777777, CREG_AXI_M_SLV1(M_GPU));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_GPU));
        writel(0x76543210, CREG_AXI_M_OFT1(M_GPU));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_GPU));

        writel(0x77777777, CREG_AXI_M_SLV0(M_DMAC_0));
        writel(0x77777777, CREG_AXI_M_SLV1(M_DMAC_0));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_DMAC_0));
        writel(0x76543210, CREG_AXI_M_OFT1(M_DMAC_0));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_DMAC_0));

        writel(0x77777777, CREG_AXI_M_SLV0(M_DMAC_1));
        writel(0x77777777, CREG_AXI_M_SLV1(M_DMAC_1));
        writel(0xFEDCBA98, CREG_AXI_M_OFT0(M_DMAC_1));
        writel(0x76543210, CREG_AXI_M_OFT1(M_DMAC_1));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_DMAC_1));

        writel(0x00000000, CREG_AXI_M_SLV0(M_DVFS));
        writel(0x60000000, CREG_AXI_M_SLV1(M_DVFS));
        writel(0x00000000, CREG_AXI_M_OFT0(M_DVFS));
        writel(0x00000000, CREG_AXI_M_OFT1(M_DVFS));
        writel(UPDATE_VAL, CREG_AXI_M_UPDT(M_DVFS));

        writel(0x00000000, CREG_PAE);
        writel(UPDATE_VAL, CREG_PAE_UPDT);
}

static void setup_clocks(void)
{
        ulong rate;

        /* Setup CPU clock */
        if (env_common.cpu_freq.set) {
                rate = env_common.cpu_freq.val;
                soc_clk_ctl("cpu-clk", &rate, CLK_ON | CLK_SET | CLK_MHZ);
        }

        /* Setup TUN clock */
        if (env_common.tun_freq.set) {
                rate = env_common.tun_freq.val;
                if (rate)
                        soc_clk_ctl("tun-clk", &rate, CLK_ON | CLK_SET | CLK_MHZ);
                else
                        soc_clk_ctl("tun-clk", NULL, CLK_OFF);
        }

        if (env_common.axi_freq.set) {
                rate = env_common.axi_freq.val;
                soc_clk_ctl("axi-clk", &rate, CLK_SET | CLK_ON | CLK_MHZ);
        }
}

static void do_init_cluster(void)
{
        /*
         * A multi-core ARC HS configuration always includes only one
         * ARC_AUX_NON_VOLATILE_LIMIT register, which is shared by all the
         * cores.
         */
        init_cluster_nvlim();
}

static int check_master_cpu_id(void)
{
        if (CPU_ID_GET() == MASTER_CPU_ID)
                return 0;

        pr_err("u-boot runs on non-master cpu with id: %lu\n", CPU_ID_GET());

        return -ENOENT;
}

static noinline int prepare_cpus(void)
{
        int ret;

        ret = check_master_cpu_id();
        if (ret)
                return ret;

        ret = envs_process_and_validate(env_map_common, env_map_core, is_cpu_used);
        if (ret)
                return ret;

        printf("CPU start mask is %#x\n", env_common.core_mask.val);

        do_init_slave_cpus();
        do_init_master_cpu();
        do_init_cluster();

        return 0;
}

static int hsdk_go_run(u32 cpu_start_reg)
{
        /* Cleanup caches, disable interrupts */
        cleanup_before_go();

        if (env_common.halt_on_boot)
                halt_this_cpu();

        /*
         * 3 NOPs after FLAG 1 instruction are no longer required for ARCv2
         * cores but we leave them for gebug purposes.
         */
        __builtin_arc_nop();
        __builtin_arc_nop();
        __builtin_arc_nop();

        /* Kick chosen slave CPUs */
        writel(cpu_start_reg, (void __iomem *)CREG_CPU_START);

        if (is_cpu_used(MASTER_CPU_ID))
                ((void (*)(void))(env_core.entry[MASTER_CPU_ID].val))();
        else
                halt_this_cpu();

        pr_err("u-boot still runs on cpu [%ld]\n", CPU_ID_GET());

        /*
         * We will never return after executing our program if master cpu used
         * otherwise halt master cpu manually.
         */
        while (true)
                halt_this_cpu();

        return 0;
}

int board_prep_linux(bootm_headers_t *images)
{
        int ret, ofst;
        char mask[15];

        ret = envs_read_validate_common(env_map_mask);
        if (ret)
                return ret;

        /* Rollback to default values */
        if (!env_common.core_mask.set) {
                env_common.core_mask.val = ALL_CPU_MASK;
                env_common.core_mask.set = true;
        }

        printf("CPU start mask is %#x\n", env_common.core_mask.val);

        if (!is_cpu_used(MASTER_CPU_ID))
                pr_err("ERR: try to launch linux with CPU[0] disabled! It doesn't work for ARC.\n");

        /*
         * If we want to launch linux on all CPUs we don't need to patch
         * linux DTB as it is default configuration
         */
        if (env_common.core_mask.val == ALL_CPU_MASK)
                return 0;

        if (!IMAGE_ENABLE_OF_LIBFDT || !images->ft_len) {
                pr_err("WARN: core_mask setup will work properly only with external DTB!\n");
                return 0;
        }

        /* patch '/possible-cpus' property according to cpu mask */
        ofst = fdt_path_offset(images->ft_addr, "/");
        sprintf(mask, "%s%s%s%s",
                is_cpu_used(0) ? "0," : "",
                is_cpu_used(1) ? "1," : "",
                is_cpu_used(2) ? "2," : "",
                is_cpu_used(3) ? "3," : "");
        ret = fdt_setprop_string(images->ft_addr, ofst, "possible-cpus", mask);
        /*
         * If we failed to patch '/possible-cpus' property we don't need break
         * linux loading process: kernel will handle it but linux will print
         * warning like "Timeout: CPU1 FAILED to comeup !!!".
         * So warn here about error, but return 0 like no error had occurred.
         */
        if (ret)
                pr_err("WARN: failed to patch '/possible-cpus' property, ret=%d\n",
                       ret);

        return 0;
}

void board_jump_and_run(ulong entry, int zero, int arch, uint params)
{
        void (*kernel_entry)(int zero, int arch, uint params);
        u32 cpu_start_reg;

        kernel_entry = (void (*)(int, int, uint))entry;

        /* Prepare CREG_CPU_START for kicking chosen CPUs */
        cpu_start_reg = prepare_cpu_ctart_reg();

        /* In case of run without hsdk_init */
        slave_cpu_set_boot_addr(entry);

        /* In case of run with hsdk_init */
        for (u32 i = 0; i < NR_CPUS; i++) {
                env_core.entry[i].val = entry;
                env_core.entry[i].set = true;
        }
        /* sync cross_cpu struct as we updated core-entry variables */
        sync_cross_cpu_data();

        /* Kick chosen slave CPUs */
        writel(cpu_start_reg, (void __iomem *)CREG_CPU_START);

        if (is_cpu_used(0))
                kernel_entry(zero, arch, params);
}

static int hsdk_go_prepare_and_run(void)
{
        /* Prepare CREG_CPU_START for kicking chosen CPUs */
        u32 reg = prepare_cpu_ctart_reg();

        if (env_common.halt_on_boot)
                printf("CPU will halt before application start, start application with debugger.\n");

        return hsdk_go_run(reg);
}

static int do_hsdk_go(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
        int ret;

        /*
         * Check for 'halt' parameter. 'halt' = enter halt-mode just before
         * starting the application; can be used for debug.
         */
        if (argc > 1) {
                env_common.halt_on_boot = !strcmp(argv[1], "halt");
                if (!env_common.halt_on_boot) {
                        pr_err("Unrecognised parameter: \'%s\'\n", argv[1]);
                        return CMD_RET_FAILURE;
                }
        }

        ret = check_master_cpu_id();
        if (ret)
                return ret;

        ret = envs_process_and_validate(env_map_mask, env_map_go, is_cpu_used);
        if (ret)
                return ret;

        /* sync cross_cpu struct as we updated core-entry variables */
        sync_cross_cpu_data();

        ret = hsdk_go_prepare_and_run();

        return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
}

U_BOOT_CMD(
        hsdk_go, 3, 0, do_hsdk_go,
        "Synopsys HSDK specific command",
        "     - Boot stand-alone application on HSDK\n"
        "hsdk_go halt - Boot stand-alone application on HSDK, halt CPU just before application run\n"
);

static int do_hsdk_init(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
        static bool done = false;
        int ret;

        /* hsdk_init can be run only once */
        if (done) {
                printf("HSDK HW is already initialized! Please reset the board if you want to change the configuration.\n");
                return CMD_RET_FAILURE;
        }

        ret = prepare_cpus();
        if (!ret)
                done = true;

        return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
}

U_BOOT_CMD(
        hsdk_init, 1, 0, do_hsdk_init,
        "Synopsys HSDK specific command",
        "- Init HSDK HW\n"
);

static int do_hsdk_clock_set(cmd_tbl_t *cmdtp, int flag, int argc,
                             char *const argv[])
{
        int ret = 0;

        /* Strip off leading subcommand argument */
        argc--;
        argv++;

        envs_cleanup_common(env_map_clock);

        if (!argc) {
                printf("Set clocks to values specified in environment\n");
                ret = envs_read_common(env_map_clock);
        } else {
                printf("Set clocks to values specified in args\n");
                ret = args_envs_enumerate(env_map_clock, 2, argc, argv);
        }

        if (ret)
                return CMD_RET_FAILURE;

        ret = envs_validate_common(env_map_clock);
        if (ret)
                return CMD_RET_FAILURE;

        /* Setup clock tree HW */
        setup_clocks();

        return CMD_RET_SUCCESS;
}

static int do_hsdk_clock_get(cmd_tbl_t *cmdtp, int flag, int argc,
                             char *const argv[])
{
        ulong rate;

        if (soc_clk_ctl("cpu-clk", &rate, CLK_GET | CLK_MHZ))
                return CMD_RET_FAILURE;

        if (env_set_ulong("cpu_freq", rate))
                return CMD_RET_FAILURE;

        if (soc_clk_ctl("tun-clk", &rate, CLK_GET | CLK_MHZ))
                return CMD_RET_FAILURE;

        if (env_set_ulong("tun_freq", rate))
                return CMD_RET_FAILURE;

        if (soc_clk_ctl("axi-clk", &rate, CLK_GET | CLK_MHZ))
                return CMD_RET_FAILURE;

        if (env_set_ulong("axi_freq", rate))
                return CMD_RET_FAILURE;

        printf("Clock values are saved to environment\n");

        return CMD_RET_SUCCESS;
}

static int do_hsdk_clock_print(cmd_tbl_t *cmdtp, int flag, int argc,
                               char *const argv[])
{
        /* Main clocks */
        soc_clk_ctl("cpu-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("tun-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("axi-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("ddr-clk", NULL, CLK_PRINT | CLK_MHZ);

        return CMD_RET_SUCCESS;
}

static int do_hsdk_clock_print_all(cmd_tbl_t *cmdtp, int flag, int argc,
                                   char *const argv[])
{
        /*
         * NOTE: as of today we don't use some peripherals like HDMI / EBI
         * so we don't want to print their clocks ("hdmi-sys-clk", "hdmi-pll",
         * "hdmi-clk", "ebi-clk"). Nevertheless their clock subsystems is fully
         * functional and we can print their clocks if it is required
         */

        /* CPU clock domain */
        soc_clk_ctl("cpu-pll", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("cpu-clk", NULL, CLK_PRINT | CLK_MHZ);
        printf("\n");

        /* SYS clock domain */
        soc_clk_ctl("sys-pll", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("apb-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("axi-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("eth-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("usb-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("sdio-clk", NULL, CLK_PRINT | CLK_MHZ);
/*      soc_clk_ctl("hdmi-sys-clk", NULL, CLK_PRINT | CLK_MHZ); */
        soc_clk_ctl("gfx-core-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("gfx-dma-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("gfx-cfg-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("dmac-core-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("dmac-cfg-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("sdio-ref-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("spi-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("i2c-clk", NULL, CLK_PRINT | CLK_MHZ);
/*      soc_clk_ctl("ebi-clk", NULL, CLK_PRINT | CLK_MHZ); */
        soc_clk_ctl("uart-clk", NULL, CLK_PRINT | CLK_MHZ);
        printf("\n");

        /* DDR clock domain */
        soc_clk_ctl("ddr-clk", NULL, CLK_PRINT | CLK_MHZ);
        printf("\n");

        /* HDMI clock domain */
/*      soc_clk_ctl("hdmi-pll", NULL, CLK_PRINT | CLK_MHZ); */
/*      soc_clk_ctl("hdmi-clk", NULL, CLK_PRINT | CLK_MHZ); */
/*      printf("\n"); */

        /* TUN clock domain */
        soc_clk_ctl("tun-pll", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("tun-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("rom-clk", NULL, CLK_PRINT | CLK_MHZ);
        soc_clk_ctl("pwm-clk", NULL, CLK_PRINT | CLK_MHZ);
        printf("\n");

        return CMD_RET_SUCCESS;
}

cmd_tbl_t cmd_hsdk_clock[] = {
        U_BOOT_CMD_MKENT(set, 3, 0, do_hsdk_clock_set, "", ""),
        U_BOOT_CMD_MKENT(get, 3, 0, do_hsdk_clock_get, "", ""),
        U_BOOT_CMD_MKENT(print, 4, 0, do_hsdk_clock_print, "", ""),
        U_BOOT_CMD_MKENT(print_all, 4, 0, do_hsdk_clock_print_all, "", ""),
};

static int do_hsdk_clock(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
        cmd_tbl_t *c;

        if (argc < 2)
                return CMD_RET_USAGE;

        /* Strip off leading 'hsdk_clock' command argument */
        argc--;
        argv++;

        c = find_cmd_tbl(argv[0], cmd_hsdk_clock, ARRAY_SIZE(cmd_hsdk_clock));
        if (!c)
                return CMD_RET_USAGE;

        return c->cmd(cmdtp, flag, argc, argv);
}

U_BOOT_CMD(
        hsdk_clock, CONFIG_SYS_MAXARGS, 0, do_hsdk_clock,
        "Synopsys HSDK specific clock command",
        "set   - Set clock to values specified in environment / command line arguments\n"
        "hsdk_clock get   - Save clock values to environment\n"
        "hsdk_clock print - Print main clock values to console\n"
        "hsdk_clock print_all - Print all clock values to console\n"
);

/* init calls */
int board_early_init_f(void)
{
        /*
         * Setup AXI apertures unconditionally as we want to have DDR
         * in 0x00000000 region when we are kicking slave cpus.
         */
        init_memory_bridge();

        /*
         * Switch SDIO external ciu clock divider from default div-by-8 to
         * minimum possible div-by-2.
         */
        writel(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *)SDIO_UHS_REG_EXT);

        return 0;
}

int board_early_init_r(void)
{
        /*
         * TODO: Init USB here to be able read environment from USB MSD.
         * It can be done with usb_init() call. We can't do it right now
         * due to brocken USB IP SW reset and lack of USB IP HW reset in

         * linux kernel (if we init USB here we will break USB in linux)
         */

        /*
         * Flush all d$ as we want to use uncached area with st.di / ld.di
         * instructions and we don't want to have any dirty line in L1d$ or SL$
         * in this area. It is enough to flush all d$ once here as we access to
         * uncached area with regular st (non .di) instruction only when we copy
         * data during u-boot relocation.
         */
        flush_dcache_all();

        printf("Relocation Offset is: %08lx\n", gd->reloc_off);

        return 0;
}

int board_late_init(void)
{
        /*
         * Populate environment with clock frequency values -
         * run hsdk_clock get callback without uboot command run.
         */
        do_hsdk_clock_get(NULL, 0, 0, NULL);

        return 0;
}

int checkboard(void)
{
        puts("Board: Synopsys ARC HS Development Kit\n");
        return 0;
};