/*
 *  MIPS emulation helpers for qemu.
 *
 *  Copyright (c) 2004-2005 Jocelyn Mayer
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "qemu/osdep.h"
#include "cpu.h"
#include "internal.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
#include "exec/memop.h"
#include "fpu_helper.h"

static inline target_ulong bitswap(target_ulong v)
{
    v = ((v >> 1) & (target_ulong)0x5555555555555555ULL) |
              ((v & (target_ulong)0x5555555555555555ULL) << 1);
    v = ((v >> 2) & (target_ulong)0x3333333333333333ULL) |
              ((v & (target_ulong)0x3333333333333333ULL) << 2);
    v = ((v >> 4) & (target_ulong)0x0F0F0F0F0F0F0F0FULL) |
              ((v & (target_ulong)0x0F0F0F0F0F0F0F0FULL) << 4);
    return v;
}

#ifdef TARGET_MIPS64
target_ulong helper_dbitswap(target_ulong rt)
{
    return bitswap(rt);
}
#endif

target_ulong helper_bitswap(target_ulong rt)
{
    return (int32_t)bitswap(rt);
}

target_ulong helper_rotx(target_ulong rs, uint32_t shift, uint32_t shiftx,
                        uint32_t stripe)
{
    int i;
    uint64_t tmp0 = ((uint64_t)rs) << 32 | ((uint64_t)rs & 0xffffffff);
    uint64_t tmp1 = tmp0;
    for (i = 0; i <= 46; i++) {
        int s;
        if (i & 0x8) {
            s = shift;
        } else {
            s = shiftx;
        }

        if (stripe != 0 && !(i & 0x4)) {
            s = ~s;
        }
        if (s & 0x10) {
            if (tmp0 & (1LL << (i + 16))) {
                tmp1 |= 1LL << i;
            } else {
                tmp1 &= ~(1LL << i);
            }
        }
    }

    uint64_t tmp2 = tmp1;
    for (i = 0; i <= 38; i++) {
        int s;
        if (i & 0x4) {
            s = shift;
        } else {
            s = shiftx;
        }

        if (s & 0x8) {
            if (tmp1 & (1LL << (i + 8))) {
                tmp2 |= 1LL << i;
            } else {
                tmp2 &= ~(1LL << i);
            }
        }
    }

    uint64_t tmp3 = tmp2;
    for (i = 0; i <= 34; i++) {
        int s;
        if (i & 0x2) {
            s = shift;
        } else {
            s = shiftx;
        }
        if (s & 0x4) {
            if (tmp2 & (1LL << (i + 4))) {
                tmp3 |= 1LL << i;
            } else {
                tmp3 &= ~(1LL << i);
            }
        }
    }

    uint64_t tmp4 = tmp3;
    for (i = 0; i <= 32; i++) {
        int s;
        if (i & 0x1) {
            s = shift;
        } else {
            s = shiftx;
        }
        if (s & 0x2) {
            if (tmp3 & (1LL << (i + 2))) {
                tmp4 |= 1LL << i;
            } else {
                tmp4 &= ~(1LL << i);
            }
        }
    }

    uint64_t tmp5 = tmp4;
    for (i = 0; i <= 31; i++) {
        int s;
        s = shift;
        if (s & 0x1) {
            if (tmp4 & (1LL << (i + 1))) {
                tmp5 |= 1LL << i;
            } else {
                tmp5 &= ~(1LL << i);
            }
        }
    }

    return (int64_t)(int32_t)(uint32_t)tmp5;
}

void helper_fork(target_ulong arg1, target_ulong arg2)
{
    /*
     * arg1 = rt, arg2 = rs
     * TODO: store to TC register
     */
}

target_ulong helper_yield(CPUMIPSState *env, target_ulong arg)
{
    target_long arg1 = arg;

    if (arg1 < 0) {
        /* No scheduling policy implemented. */
        if (arg1 != -2) {
            if (env->CP0_VPEControl & (1 << CP0VPECo_YSI) &&
                env->active_tc.CP0_TCStatus & (1 << CP0TCSt_DT)) {
                env->CP0_VPEControl &= ~(0x7 << CP0VPECo_EXCPT);
                env->CP0_VPEControl |= 4 << CP0VPECo_EXCPT;
                do_raise_exception(env, EXCP_THREAD, GETPC());
            }
        }
    } else if (arg1 == 0) {
        if (0) {
            /* TODO: TC underflow */
            env->CP0_VPEControl &= ~(0x7 << CP0VPECo_EXCPT);
            do_raise_exception(env, EXCP_THREAD, GETPC());
        } else {
            /* TODO: Deallocate TC */
        }
    } else if (arg1 > 0) {
        /* Yield qualifier inputs not implemented. */
        env->CP0_VPEControl &= ~(0x7 << CP0VPECo_EXCPT);
        env->CP0_VPEControl |= 2 << CP0VPECo_EXCPT;
        do_raise_exception(env, EXCP_THREAD, GETPC());
    }
    return env->CP0_YQMask;
}

static inline void check_hwrena(CPUMIPSState *env, int reg, uintptr_t pc)
{
    if ((env->hflags & MIPS_HFLAG_CP0) || (env->CP0_HWREna & (1 << reg))) {
        return;
    }
    do_raise_exception(env, EXCP_RI, pc);
}

target_ulong helper_rdhwr_cpunum(CPUMIPSState *env)
{
    check_hwrena(env, 0, GETPC());
    return env->CP0_EBase & 0x3ff;
}

target_ulong helper_rdhwr_synci_step(CPUMIPSState *env)
{
    check_hwrena(env, 1, GETPC());
    return env->SYNCI_Step;
}

target_ulong helper_rdhwr_cc(CPUMIPSState *env)
{
    check_hwrena(env, 2, GETPC());
#ifdef CONFIG_USER_ONLY
    return env->CP0_Count;
#else
    return (int32_t)cpu_mips_get_count(env);
#endif
}

target_ulong helper_rdhwr_ccres(CPUMIPSState *env)
{
    check_hwrena(env, 3, GETPC());
    return env->CCRes;
}

target_ulong helper_rdhwr_performance(CPUMIPSState *env)
{
    check_hwrena(env, 4, GETPC());
    return env->CP0_Performance0;
}

target_ulong helper_rdhwr_xnp(CPUMIPSState *env)
{
    check_hwrena(env, 5, GETPC());
    return (env->CP0_Config5 >> CP0C5_XNP) & 1;
}

void helper_pmon(CPUMIPSState *env, int function)
{
    function /= 2;
    switch (function) {
    case 2: /* TODO: char inbyte(int waitflag); */
        if (env->active_tc.gpr[4] == 0) {
            env->active_tc.gpr[2] = -1;
        }
        /* Fall through */
    case 11: /* TODO: char inbyte (void); */
        env->active_tc.gpr[2] = -1;
        break;
    case 3:
    case 12:
        printf("%c", (char)(env->active_tc.gpr[4] & 0xFF));
        break;
    case 17:
        break;
    case 158:
        {
            unsigned char *fmt = (void *)(uintptr_t)env->active_tc.gpr[4];
            printf("%s", fmt);
        }
        break;
    }
}

#if !defined(CONFIG_USER_ONLY)

void mips_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
                                  MMUAccessType access_type,
                                  int mmu_idx, uintptr_t retaddr)
{
    MIPSCPU *cpu = MIPS_CPU(cs);
    CPUMIPSState *env = &cpu->env;
    int error_code = 0;
    int excp;

    if (!(env->hflags & MIPS_HFLAG_DM)) {
        env->CP0_BadVAddr = addr;
    }

    if (access_type == MMU_DATA_STORE) {
        excp = EXCP_AdES;
    } else {
        excp = EXCP_AdEL;
        if (access_type == MMU_INST_FETCH) {
            error_code |= EXCP_INST_NOTAVAIL;
        }
    }

    do_raise_exception_err(env, excp, error_code, retaddr);
}

void mips_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
                                    vaddr addr, unsigned size,
                                    MMUAccessType access_type,
                                    int mmu_idx, MemTxAttrs attrs,
                                    MemTxResult response, uintptr_t retaddr)
{
    MIPSCPU *cpu = MIPS_CPU(cs);
    MIPSCPUClass *mcc = MIPS_CPU_GET_CLASS(cpu);
    CPUMIPSState *env = &cpu->env;

    if (access_type == MMU_INST_FETCH) {
        do_raise_exception(env, EXCP_IBE, retaddr);
    } else if (!mcc->no_data_aborts) {
        do_raise_exception(env, EXCP_DBE, retaddr);
    }
}
#endif /* !CONFIG_USER_ONLY */
