/*
 *  S/390 misc helper routines
 *
 *  Copyright (c) 2009 Ulrich Hecht
 *  Copyright (c) 2009 Alexander Graf
 *
 * 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 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 "cpu.h"
#include "exec/memory.h"
#include "qemu/host-utils.h"
#include "helper.h"
#include <string.h>
#include "sysemu/kvm.h"
#include "qemu/timer.h"
#ifdef CONFIG_KVM
#include <linux/kvm.h>
#endif

#if !defined(CONFIG_USER_ONLY)
#include "exec/softmmu_exec.h"
#include "sysemu/cpus.h"
#include "sysemu/sysemu.h"
#endif

/* #define DEBUG_HELPER */
#ifdef DEBUG_HELPER
#define HELPER_LOG(x...) qemu_log(x)
#else
#define HELPER_LOG(x...)
#endif

/* Raise an exception dynamically from a helper function.  */
void QEMU_NORETURN runtime_exception(CPUS390XState *env, int excp,
                                     uintptr_t retaddr)
{
    int t;

    env->exception_index = EXCP_PGM;
    env->int_pgm_code = excp;

    /* Use the (ultimate) callers address to find the insn that trapped.  */
    cpu_restore_state(env, retaddr);

    /* Advance past the insn.  */
    t = cpu_ldub_code(env, env->psw.addr);
    env->int_pgm_ilen = t = get_ilen(t);
    env->psw.addr += 2 * t;

    cpu_loop_exit(env);
}

/* Raise an exception statically from a TB.  */
void HELPER(exception)(CPUS390XState *env, uint32_t excp)
{
    HELPER_LOG("%s: exception %d\n", __func__, excp);
    env->exception_index = excp;
    cpu_loop_exit(env);
}

#ifndef CONFIG_USER_ONLY

/* EBCDIC handling */
static const uint8_t ebcdic2ascii[] = {
    0x00, 0x01, 0x02, 0x03, 0x07, 0x09, 0x07, 0x7F,
    0x07, 0x07, 0x07, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
    0x10, 0x11, 0x12, 0x13, 0x07, 0x0A, 0x08, 0x07,
    0x18, 0x19, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
    0x07, 0x07, 0x1C, 0x07, 0x07, 0x0A, 0x17, 0x1B,
    0x07, 0x07, 0x07, 0x07, 0x07, 0x05, 0x06, 0x07,
    0x07, 0x07, 0x16, 0x07, 0x07, 0x07, 0x07, 0x04,
    0x07, 0x07, 0x07, 0x07, 0x14, 0x15, 0x07, 0x1A,
    0x20, 0xFF, 0x83, 0x84, 0x85, 0xA0, 0x07, 0x86,
    0x87, 0xA4, 0x5B, 0x2E, 0x3C, 0x28, 0x2B, 0x21,
    0x26, 0x82, 0x88, 0x89, 0x8A, 0xA1, 0x8C, 0x07,
    0x8D, 0xE1, 0x5D, 0x24, 0x2A, 0x29, 0x3B, 0x5E,
    0x2D, 0x2F, 0x07, 0x8E, 0x07, 0x07, 0x07, 0x8F,
    0x80, 0xA5, 0x07, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
    0x07, 0x90, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
    0x70, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
    0x07, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
    0x68, 0x69, 0xAE, 0xAF, 0x07, 0x07, 0x07, 0xF1,
    0xF8, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
    0x71, 0x72, 0xA6, 0xA7, 0x91, 0x07, 0x92, 0x07,
    0xE6, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
    0x79, 0x7A, 0xAD, 0xAB, 0x07, 0x07, 0x07, 0x07,
    0x9B, 0x9C, 0x9D, 0xFA, 0x07, 0x07, 0x07, 0xAC,
    0xAB, 0x07, 0xAA, 0x7C, 0x07, 0x07, 0x07, 0x07,
    0x7B, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
    0x48, 0x49, 0x07, 0x93, 0x94, 0x95, 0xA2, 0x07,
    0x7D, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
    0x51, 0x52, 0x07, 0x96, 0x81, 0x97, 0xA3, 0x98,
    0x5C, 0xF6, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
    0x59, 0x5A, 0xFD, 0x07, 0x99, 0x07, 0x07, 0x07,
    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
    0x38, 0x39, 0x07, 0x07, 0x9A, 0x07, 0x07, 0x07,
};

static const uint8_t ascii2ebcdic[] = {
    0x00, 0x01, 0x02, 0x03, 0x37, 0x2D, 0x2E, 0x2F,
    0x16, 0x05, 0x15, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
    0x10, 0x11, 0x12, 0x13, 0x3C, 0x3D, 0x32, 0x26,
    0x18, 0x19, 0x3F, 0x27, 0x22, 0x1D, 0x1E, 0x1F,
    0x40, 0x5A, 0x7F, 0x7B, 0x5B, 0x6C, 0x50, 0x7D,
    0x4D, 0x5D, 0x5C, 0x4E, 0x6B, 0x60, 0x4B, 0x61,
    0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
    0xF8, 0xF9, 0x7A, 0x5E, 0x4C, 0x7E, 0x6E, 0x6F,
    0x7C, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
    0xC8, 0xC9, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
    0xD7, 0xD8, 0xD9, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6,
    0xE7, 0xE8, 0xE9, 0xBA, 0xE0, 0xBB, 0xB0, 0x6D,
    0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
    0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
    0x97, 0x98, 0x99, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
    0xA7, 0xA8, 0xA9, 0xC0, 0x4F, 0xD0, 0xA1, 0x07,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x59, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3F,
    0x90, 0x3F, 0x3F, 0x3F, 0x3F, 0xEA, 0x3F, 0xFF
};

static inline void ebcdic_put(uint8_t *p, const char *ascii, int len)
{
    int i;

    for (i = 0; i < len; i++) {
        p[i] = ascii2ebcdic[(uint8_t)ascii[i]];
    }
}

void program_interrupt(CPUS390XState *env, uint32_t code, int ilen)
{
    qemu_log_mask(CPU_LOG_INT, "program interrupt at %#" PRIx64 "\n",
                  env->psw.addr);

    if (kvm_enabled()) {
#ifdef CONFIG_KVM
        kvm_s390_interrupt(s390_env_get_cpu(env), KVM_S390_PROGRAM_INT, code);
#endif
    } else {
        env->int_pgm_code = code;
        env->int_pgm_ilen = ilen;
        env->exception_index = EXCP_PGM;
        cpu_loop_exit(env);
    }
}

/* SCLP service call */
uint32_t HELPER(servc)(CPUS390XState *env, uint64_t r1, uint64_t r2)
{
    int r = sclp_service_call(r1, r2);
    if (r < 0) {
        program_interrupt(env, -r, 4);
        return 0;
    }
    return r;
}

#ifndef CONFIG_USER_ONLY
static void cpu_reset_all(void)
{
    CPUState *cpu;
    S390CPUClass *scc;

    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
        scc = S390_CPU_GET_CLASS(CPU(cpu));
        scc->cpu_reset(CPU(cpu));
    }
}

static int load_normal_reset(S390CPU *cpu)
{
    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);

    pause_all_vcpus();
    cpu_synchronize_all_states();
    cpu_reset_all();
    io_subsystem_reset();
    scc->initial_cpu_reset(CPU(cpu));
    scc->load_normal(CPU(cpu));
    cpu_synchronize_all_post_reset();
    resume_all_vcpus();
    return 0;
}

#define DIAG_308_RC_NO_CONF         0x0102
#define DIAG_308_RC_INVALID         0x0402
void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3)
{
    uint64_t addr =  env->regs[r1];
    uint64_t subcode = env->regs[r3];

    if (env->psw.mask & PSW_MASK_PSTATE) {
        program_interrupt(env, PGM_PRIVILEGED, ILEN_LATER_INC);
        return;
    }

    if ((subcode & ~0x0ffffULL) || (subcode > 6)) {
        program_interrupt(env, PGM_SPECIFICATION, ILEN_LATER_INC);
        return;
    }

    switch (subcode) {
    case 1:
        load_normal_reset(s390_env_get_cpu(env));
        break;
    case 5:
        if ((r1 & 1) || (addr & 0x0fffULL)) {
            program_interrupt(env, PGM_SPECIFICATION, ILEN_LATER_INC);
            return;
        }
        env->regs[r1+1] = DIAG_308_RC_INVALID;
        return;
    case 6:
        if ((r1 & 1) || (addr & 0x0fffULL)) {
            program_interrupt(env, PGM_SPECIFICATION, ILEN_LATER_INC);
            return;
        }
        env->regs[r1+1] = DIAG_308_RC_NO_CONF;
        return;
    default:
        hw_error("Unhandled diag308 subcode %" PRIx64, subcode);
        break;
    }
}
#endif

/* DIAG */
uint64_t HELPER(diag)(CPUS390XState *env, uint32_t num, uint64_t mem,
                      uint64_t code)
{
    uint64_t r;

    switch (num) {
    case 0x500:
        /* KVM hypercall */
        r = s390_virtio_hypercall(env);
        break;
    case 0x44:
        /* yield */
        r = 0;
        break;
    case 0x308:
        /* ipl */
        r = 0;
        break;
    default:
        r = -1;
        break;
    }

    if (r) {
        program_interrupt(env, PGM_OPERATION, ILEN_LATER_INC);
    }

    return r;
}

/* Set Prefix */
void HELPER(spx)(CPUS390XState *env, uint64_t a1)
{
    uint32_t prefix = a1 & 0x7fffe000;
    env->psa = prefix;
    qemu_log("prefix: %#x\n", prefix);
    tlb_flush_page(env, 0);
    tlb_flush_page(env, TARGET_PAGE_SIZE);
}

static inline uint64_t clock_value(CPUS390XState *env)
{
    uint64_t time;

    time = env->tod_offset +
        time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - env->tod_basetime);

    return time;
}

/* Store Clock */
uint64_t HELPER(stck)(CPUS390XState *env)
{
    return clock_value(env);
}

/* Set Clock Comparator */
void HELPER(sckc)(CPUS390XState *env, uint64_t time)
{
    if (time == -1ULL) {
        return;
    }

    /* difference between now and then */
    time -= clock_value(env);
    /* nanoseconds */
    time = (time * 125) >> 9;

    timer_mod(env->tod_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + time);
}

/* Store Clock Comparator */
uint64_t HELPER(stckc)(CPUS390XState *env)
{
    /* XXX implement */
    return 0;
}

/* Set CPU Timer */
void HELPER(spt)(CPUS390XState *env, uint64_t time)
{
    if (time == -1ULL) {
        return;
    }

    /* nanoseconds */
    time = (time * 125) >> 9;

    timer_mod(env->cpu_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + time);
}

/* Store CPU Timer */
uint64_t HELPER(stpt)(CPUS390XState *env)
{
    /* XXX implement */
    return 0;
}

/* Store System Information */
uint32_t HELPER(stsi)(CPUS390XState *env, uint64_t a0,
                      uint64_t r0, uint64_t r1)
{
    int cc = 0;
    int sel1, sel2;

    if ((r0 & STSI_LEVEL_MASK) <= STSI_LEVEL_3 &&
        ((r0 & STSI_R0_RESERVED_MASK) || (r1 & STSI_R1_RESERVED_MASK))) {
        /* valid function code, invalid reserved bits */
        program_interrupt(env, PGM_SPECIFICATION, 2);
    }

    sel1 = r0 & STSI_R0_SEL1_MASK;
    sel2 = r1 & STSI_R1_SEL2_MASK;

    /* XXX: spec exception if sysib is not 4k-aligned */

    switch (r0 & STSI_LEVEL_MASK) {
    case STSI_LEVEL_1:
        if ((sel1 == 1) && (sel2 == 1)) {
            /* Basic Machine Configuration */
            struct sysib_111 sysib;

            memset(&sysib, 0, sizeof(sysib));
            ebcdic_put(sysib.manuf, "QEMU            ", 16);
            /* same as machine type number in STORE CPU ID */
            ebcdic_put(sysib.type, "QEMU", 4);
            /* same as model number in STORE CPU ID */
            ebcdic_put(sysib.model, "QEMU            ", 16);
            ebcdic_put(sysib.sequence, "QEMU            ", 16);
            ebcdic_put(sysib.plant, "QEMU", 4);
            cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
        } else if ((sel1 == 2) && (sel2 == 1)) {
            /* Basic Machine CPU */
            struct sysib_121 sysib;

            memset(&sysib, 0, sizeof(sysib));
            /* XXX make different for different CPUs? */
            ebcdic_put(sysib.sequence, "QEMUQEMUQEMUQEMU", 16);
            ebcdic_put(sysib.plant, "QEMU", 4);
            stw_p(&sysib.cpu_addr, env->cpu_num);
            cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
        } else if ((sel1 == 2) && (sel2 == 2)) {
            /* Basic Machine CPUs */
            struct sysib_122 sysib;

            memset(&sysib, 0, sizeof(sysib));
            stl_p(&sysib.capability, 0x443afc29);
            /* XXX change when SMP comes */
            stw_p(&sysib.total_cpus, 1);
            stw_p(&sysib.active_cpus, 1);
            stw_p(&sysib.standby_cpus, 0);
            stw_p(&sysib.reserved_cpus, 0);
            cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
        } else {
            cc = 3;
        }
        break;
    case STSI_LEVEL_2:
        {
            if ((sel1 == 2) && (sel2 == 1)) {
                /* LPAR CPU */
                struct sysib_221 sysib;

                memset(&sysib, 0, sizeof(sysib));
                /* XXX make different for different CPUs? */
                ebcdic_put(sysib.sequence, "QEMUQEMUQEMUQEMU", 16);
                ebcdic_put(sysib.plant, "QEMU", 4);
                stw_p(&sysib.cpu_addr, env->cpu_num);
                stw_p(&sysib.cpu_id, 0);
                cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
            } else if ((sel1 == 2) && (sel2 == 2)) {
                /* LPAR CPUs */
                struct sysib_222 sysib;

                memset(&sysib, 0, sizeof(sysib));
                stw_p(&sysib.lpar_num, 0);
                sysib.lcpuc = 0;
                /* XXX change when SMP comes */
                stw_p(&sysib.total_cpus, 1);
                stw_p(&sysib.conf_cpus, 1);
                stw_p(&sysib.standby_cpus, 0);
                stw_p(&sysib.reserved_cpus, 0);
                ebcdic_put(sysib.name, "QEMU    ", 8);
                stl_p(&sysib.caf, 1000);
                stw_p(&sysib.dedicated_cpus, 0);
                stw_p(&sysib.shared_cpus, 0);
                cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
            } else {
                cc = 3;
            }
            break;
        }
    case STSI_LEVEL_3:
        {
            if ((sel1 == 2) && (sel2 == 2)) {
                /* VM CPUs */
                struct sysib_322 sysib;

                memset(&sysib, 0, sizeof(sysib));
                sysib.count = 1;
                /* XXX change when SMP comes */
                stw_p(&sysib.vm[0].total_cpus, 1);
                stw_p(&sysib.vm[0].conf_cpus, 1);
                stw_p(&sysib.vm[0].standby_cpus, 0);
                stw_p(&sysib.vm[0].reserved_cpus, 0);
                ebcdic_put(sysib.vm[0].name, "KVMguest", 8);
                stl_p(&sysib.vm[0].caf, 1000);
                ebcdic_put(sysib.vm[0].cpi, "KVM/Linux       ", 16);
                cpu_physical_memory_rw(a0, (uint8_t *)&sysib, sizeof(sysib), 1);
            } else {
                cc = 3;
            }
            break;
        }
    case STSI_LEVEL_CURRENT:
        env->regs[0] = STSI_LEVEL_3;
        break;
    default:
        cc = 3;
        break;
    }

    return cc;
}

uint32_t HELPER(sigp)(CPUS390XState *env, uint64_t order_code, uint32_t r1,
                      uint64_t cpu_addr)
{
    int cc = 0;

    HELPER_LOG("%s: %016" PRIx64 " %08x %016" PRIx64 "\n",
               __func__, order_code, r1, cpu_addr);

    /* Remember: Use "R1 or R1 + 1, whichever is the odd-numbered register"
       as parameter (input). Status (output) is always R1. */

    switch (order_code) {
    case SIGP_SET_ARCH:
        /* switch arch */
        break;
    case SIGP_SENSE:
        /* enumerate CPU status */
        if (cpu_addr) {
            /* XXX implement when SMP comes */
            return 3;
        }
        env->regs[r1] &= 0xffffffff00000000ULL;
        cc = 1;
        break;
#if !defined(CONFIG_USER_ONLY)
    case SIGP_RESTART:
        qemu_system_reset_request();
        cpu_loop_exit(env);
        break;
    case SIGP_STOP:
        qemu_system_shutdown_request();
        cpu_loop_exit(env);
        break;
#endif
    default:
        /* unknown sigp */
        fprintf(stderr, "XXX unknown sigp: 0x%" PRIx64 "\n", order_code);
        cc = 3;
    }

    return cc;
}
#endif