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/*

 *  S/390 helpers

 *

 *  Copyright (c) 2009 Ulrich Hecht

 *  Copyright (c) 2011 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/gdbstub.h"

#include "qemu/timer.h"

#ifndef CONFIG_USER_ONLY

#include "sysemu/sysemu.h"

#endif

//#define DEBUG_S390

//#define DEBUG_S390_PTE

//#define DEBUG_S390_STDOUT

#ifdef DEBUG_S390

#ifdef DEBUG_S390_STDOUT

#define DPRINTF(fmt, ...) \

    do { fprintf(stderr, fmt, ## __VA_ARGS__); \

         qemu_log(fmt, ##__VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) \

    do { qemu_log(fmt, ## __VA_ARGS__); } while (0)

#endif

#else

#define DPRINTF(fmt, ...) \

    do { } while (0)

#endif

#ifdef DEBUG_S390_PTE

#define PTE_DPRINTF DPRINTF

#else

#define PTE_DPRINTF(fmt, ...) \

    do { } while (0)

#endif

#ifndef CONFIG_USER_ONLY

void s390x_tod_timer(void *opaque)

{

    S390CPU *cpu = opaque;

    CPUS390XState *env = &cpu->env;

    env->pending_int |= INTERRUPT_TOD;

    cpu_interrupt(env, CPU_INTERRUPT_HARD);

}

void s390x_cpu_timer(void *opaque)

{

    S390CPU *cpu = opaque;

    CPUS390XState *env = &cpu->env;

    env->pending_int |= INTERRUPT_CPUTIMER;

    cpu_interrupt(env, CPU_INTERRUPT_HARD);

}

#endif

S390CPU *cpu_s390x_init(const char *cpu_model)

{

    S390CPU *cpu;

    CPUS390XState *env;

    static int inited;

    cpu = S390_CPU(object_new(TYPE_S390_CPU));

    env = &cpu->env;

    if (tcg_enabled() && !inited) {

        inited = 1;

        s390x_translate_init();

    }

    env->cpu_model_str = cpu_model;

    qemu_init_vcpu(env);

    return cpu;

}

#if defined(CONFIG_USER_ONLY)

void do_interrupt(CPUS390XState *env)

{

    env->exception_index = -1;

}

int cpu_s390x_handle_mmu_fault(CPUS390XState *env, target_ulong address,

                               int rw, int mmu_idx)

{

    /* fprintf(stderr, "%s: address 0x%lx rw %d mmu_idx %d\n",

       __func__, address, rw, mmu_idx); */

    env->exception_index = EXCP_ADDR;

    /* FIXME: find out how this works on a real machine */

    env->__excp_addr = address;

    return 1;

}

#else /* !CONFIG_USER_ONLY */

/* Ensure to exit the TB after this call! */

static void trigger_pgm_exception(CPUS390XState *env, uint32_t code,

                                  uint32_t ilc)

{

    env->exception_index = EXCP_PGM;

    env->int_pgm_code = code;

    env->int_pgm_ilc = ilc;

}

static int trans_bits(CPUS390XState *env, uint64_t mode)

{

    int bits = 0;

    switch (mode) {

    case PSW_ASC_PRIMARY:

        bits = 1;

        break;

    case PSW_ASC_SECONDARY:

        bits = 2;

        break;

    case PSW_ASC_HOME:

        bits = 3;

        break;

    default:

        cpu_abort(env, "unknown asc mode\n");

        break;

    }

    return bits;

}

static void trigger_prot_fault(CPUS390XState *env, target_ulong vaddr,

                               uint64_t mode)

{

    int ilc = ILC_LATER_INC_2;

    int bits = trans_bits(env, mode) | 4;

    DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __func__, vaddr, bits);

    stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);

    trigger_pgm_exception(env, PGM_PROTECTION, ilc);

}

static void trigger_page_fault(CPUS390XState *env, target_ulong vaddr,

                               uint32_t type, uint64_t asc, int rw)

{

    int ilc = ILC_LATER;

    int bits = trans_bits(env, asc);

    if (rw == 2) {

        /* code has is undefined ilc */

        ilc = 2;

    }

    DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __func__, vaddr, bits);

    stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);

    trigger_pgm_exception(env, type, ilc);

}

static int mmu_translate_asce(CPUS390XState *env, target_ulong vaddr,

                              uint64_t asc, uint64_t asce, int level,

                              target_ulong *raddr, int *flags, int rw)

{

    uint64_t offs = 0;

    uint64_t origin;

    uint64_t new_asce;

    PTE_DPRINTF("%s: 0x%" PRIx64 "\n", __func__, asce);

    if (((level != _ASCE_TYPE_SEGMENT) && (asce & _REGION_ENTRY_INV)) ||

        ((level == _ASCE_TYPE_SEGMENT) && (asce & _SEGMENT_ENTRY_INV))) {

        /* XXX different regions have different faults */

        DPRINTF("%s: invalid region\n", __func__);

        trigger_page_fault(env, vaddr, PGM_SEGMENT_TRANS, asc, rw);

        return -1;

    }

    if ((level <= _ASCE_TYPE_MASK) && ((asce & _ASCE_TYPE_MASK) != level)) {

        trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);

        return -1;

    }

    if (asce & _ASCE_REAL_SPACE) {

        /* direct mapping */

        *raddr = vaddr;

        return 0;

    }

    origin = asce & _ASCE_ORIGIN;

    switch (level) {

    case _ASCE_TYPE_REGION1 + 4:

        offs = (vaddr >> 50) & 0x3ff8;

        break;

    case _ASCE_TYPE_REGION1:

        offs = (vaddr >> 39) & 0x3ff8;

        break;

    case _ASCE_TYPE_REGION2:

        offs = (vaddr >> 28) & 0x3ff8;

        break;

    case _ASCE_TYPE_REGION3:

        offs = (vaddr >> 17) & 0x3ff8;

        break;

    case _ASCE_TYPE_SEGMENT:

        offs = (vaddr >> 9) & 0x07f8;

        origin = asce & _SEGMENT_ENTRY_ORIGIN;

        break;

    }

    /* XXX region protection flags */

    /* *flags &= ~PAGE_WRITE */

    new_asce = ldq_phys(origin + offs);

    PTE_DPRINTF("%s: 0x%" PRIx64 " + 0x%" PRIx64 " => 0x%016" PRIx64 "\n",

                __func__, origin, offs, new_asce);

    if (level != _ASCE_TYPE_SEGMENT) {

        /* yet another region */

        return mmu_translate_asce(env, vaddr, asc, new_asce, level - 4, raddr,

                                  flags, rw);

    }

    /* PTE */

    if (new_asce & _PAGE_INVALID) {

        DPRINTF("%s: PTE=0x%" PRIx64 " invalid\n", __func__, new_asce);

        trigger_page_fault(env, vaddr, PGM_PAGE_TRANS, asc, rw);

        return -1;

    }

    if (new_asce & _PAGE_RO) {

        *flags &= ~PAGE_WRITE;

    }

    *raddr = new_asce & _ASCE_ORIGIN;

    PTE_DPRINTF("%s: PTE=0x%" PRIx64 "\n", __func__, new_asce);

    return 0;

}

static int mmu_translate_asc(CPUS390XState *env, target_ulong vaddr,

                             uint64_t asc, target_ulong *raddr, int *flags,

                             int rw)

{

    uint64_t asce = 0;

    int level, new_level;

    int r;

    switch (asc) {

    case PSW_ASC_PRIMARY:

        PTE_DPRINTF("%s: asc=primary\n", __func__);

        asce = env->cregs[1];

        break;

    case PSW_ASC_SECONDARY:

        PTE_DPRINTF("%s: asc=secondary\n", __func__);

        asce = env->cregs[7];

        break;

    case PSW_ASC_HOME:

        PTE_DPRINTF("%s: asc=home\n", __func__);

        asce = env->cregs[13];

        break;

    }

    switch (asce & _ASCE_TYPE_MASK) {

    case _ASCE_TYPE_REGION1:

        break;

    case _ASCE_TYPE_REGION2:

        if (vaddr & 0xffe0000000000000ULL) {

            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64

                    " 0xffe0000000000000ULL\n", __func__, vaddr);

            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);

            return -1;

        }

        break;

    case _ASCE_TYPE_REGION3:

        if (vaddr & 0xfffffc0000000000ULL) {

            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64

                    " 0xfffffc0000000000ULL\n", __func__, vaddr);

            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);

            return -1;

        }

        break;

    case _ASCE_TYPE_SEGMENT:

        if (vaddr & 0xffffffff80000000ULL) {

            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64

                    " 0xffffffff80000000ULL\n", __func__, vaddr);

            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);

            return -1;

        }

        break;

    }

    /* fake level above current */

    level = asce & _ASCE_TYPE_MASK;

    new_level = level + 4;

    asce = (asce & ~_ASCE_TYPE_MASK) | (new_level & _ASCE_TYPE_MASK);

    r = mmu_translate_asce(env, vaddr, asc, asce, new_level, raddr, flags, rw);

    if ((rw == 1) && !(*flags & PAGE_WRITE)) {

        trigger_prot_fault(env, vaddr, asc);

        return -1;

    }

    return r;

}

int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,

                  target_ulong *raddr, int *flags)

{

    int r = -1;

    uint8_t *sk;

    *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC;

    vaddr &= TARGET_PAGE_MASK;

    if (!(env->psw.mask & PSW_MASK_DAT)) {

        *raddr = vaddr;

        r = 0;

        goto out;

    }

    switch (asc) {

    case PSW_ASC_PRIMARY:

    case PSW_ASC_HOME:

        r = mmu_translate_asc(env, vaddr, asc, raddr, flags, rw);

        break;

    case PSW_ASC_SECONDARY:

        /*

         * Instruction: Primary

         * Data: Secondary

         */

        if (rw == 2) {

            r = mmu_translate_asc(env, vaddr, PSW_ASC_PRIMARY, raddr, flags,

                                  rw);

            *flags &= ~(PAGE_READ | PAGE_WRITE);

        } else {

            r = mmu_translate_asc(env, vaddr, PSW_ASC_SECONDARY, raddr, flags,

                                  rw);

            *flags &= ~(PAGE_EXEC);

        }

        break;

    case PSW_ASC_ACCREG:

    default:

        hw_error("guest switched to unknown asc mode\n");

        break;

    }

 out:

    /* Convert real address -> absolute address */

    if (*raddr < 0x2000) {

        *raddr = *raddr + env->psa;

    }

    if (*raddr <= ram_size) {

        sk = &env->storage_keys[*raddr / TARGET_PAGE_SIZE];

        if (*flags & PAGE_READ) {

            *sk |= SK_R;

        }

        if (*flags & PAGE_WRITE) {

            *sk |= SK_C;

        }

    }

    return r;

}

int cpu_s390x_handle_mmu_fault(CPUS390XState *env, target_ulong orig_vaddr,

                               int rw, int mmu_idx)

{

    uint64_t asc = env->psw.mask & PSW_MASK_ASC;

    target_ulong vaddr, raddr;

    int prot;

    DPRINTF("%s: address 0x%" PRIx64 " rw %d mmu_idx %d\n",

            __func__, _vaddr, rw, mmu_idx);

    orig_vaddr &= TARGET_PAGE_MASK;

    vaddr = orig_vaddr;

    /* 31-Bit mode */

    if (!(env->psw.mask & PSW_MASK_64)) {

        vaddr &= 0x7fffffff;

    }

    if (mmu_translate(env, vaddr, rw, asc, &raddr, &prot)) {

        /* Translation ended in exception */

        return 1;

    }

    /* check out of RAM access */

    if (raddr > (ram_size + virtio_size)) {

        DPRINTF("%s: aaddr %" PRIx64 " > ram_size %" PRIx64 "\n", __func__,

                (uint64_t)aaddr, (uint64_t)ram_size);

        trigger_pgm_exception(env, PGM_ADDRESSING, ILC_LATER);

        return 1;

    }

    DPRINTF("%s: set tlb %" PRIx64 " -> %" PRIx64 " (%x)\n", __func__,

            (uint64_t)vaddr, (uint64_t)raddr, prot);

    tlb_set_page(env, orig_vaddr, raddr, prot,

                 mmu_idx, TARGET_PAGE_SIZE);

    return 0;

}

hwaddr cpu_get_phys_page_debug(CPUS390XState *env,

                                           target_ulong vaddr)

{

    target_ulong raddr;

    int prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;

    int old_exc = env->exception_index;

    uint64_t asc = env->psw.mask & PSW_MASK_ASC;

    /* 31-Bit mode */

    if (!(env->psw.mask & PSW_MASK_64)) {

        vaddr &= 0x7fffffff;

    }

    mmu_translate(env, vaddr, 2, asc, &raddr, &prot);

    env->exception_index = old_exc;

    return raddr;

}

void load_psw(CPUS390XState *env, uint64_t mask, uint64_t addr)

{

    if (mask & PSW_MASK_WAIT) {

        if (!(mask & (PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK))) {

            if (s390_del_running_cpu(env) == 0) {

#ifndef CONFIG_USER_ONLY

                qemu_system_shutdown_request();

#endif

            }

        }

        env->halted = 1;

        env->exception_index = EXCP_HLT;

    }

    env->psw.addr = addr;

    env->psw.mask = mask;

    env->cc_op = (mask >> 13) & 3;

}

static uint64_t get_psw_mask(CPUS390XState *env)

{

    uint64_t r = env->psw.mask;

    env->cc_op = calc_cc(env, env->cc_op, env->cc_src, env->cc_dst, env->cc_vr);

    r &= ~(3ULL << 13);

    assert(!(env->cc_op & ~3));

    r |= env->cc_op << 13;

    return r;

}

static void do_svc_interrupt(CPUS390XState *env)

{

    uint64_t mask, addr;

    LowCore *lowcore;

    hwaddr len = TARGET_PAGE_SIZE;

    lowcore = cpu_physical_memory_map(env->psa, &len, 1);

    lowcore->svc_code = cpu_to_be16(env->int_svc_code);

    lowcore->svc_ilc = cpu_to_be16(env->int_svc_ilc);

    lowcore->svc_old_psw.mask = cpu_to_be64(get_psw_mask(env));

    lowcore->svc_old_psw.addr = cpu_to_be64(env->psw.addr + (env->int_svc_ilc));

    mask = be64_to_cpu(lowcore->svc_new_psw.mask);

    addr = be64_to_cpu(lowcore->svc_new_psw.addr);

    cpu_physical_memory_unmap(lowcore, len, 1, len);

    load_psw(env, mask, addr);

}

static void do_program_interrupt(CPUS390XState *env)

{

    uint64_t mask, addr;

    LowCore *lowcore;

    hwaddr len = TARGET_PAGE_SIZE;

    int ilc = env->int_pgm_ilc;

    switch (ilc) {

    case ILC_LATER:

        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr));

        break;

    case ILC_LATER_INC:

        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr));

        env->psw.addr += ilc * 2;

        break;

    case ILC_LATER_INC_2:

        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr)) * 2;

        env->psw.addr += ilc;

        break;

    }

    qemu_log_mask(CPU_LOG_INT, "%s: code=0x%x ilc=%d\n",

                  __func__, env->int_pgm_code, ilc);

    lowcore = cpu_physical_memory_map(env->psa, &len, 1);

    lowcore->pgm_ilc = cpu_to_be16(ilc);

    lowcore->pgm_code = cpu_to_be16(env->int_pgm_code);

    lowcore->program_old_psw.mask = cpu_to_be64(get_psw_mask(env));

    lowcore->program_old_psw.addr = cpu_to_be64(env->psw.addr);

    mask = be64_to_cpu(lowcore->program_new_psw.mask);

    addr = be64_to_cpu(lowcore->program_new_psw.addr);

    cpu_physical_memory_unmap(lowcore, len, 1, len);

    DPRINTF("%s: %x %x %" PRIx64 " %" PRIx64 "\n", __func__,

            env->int_pgm_code, ilc, env->psw.mask,

            env->psw.addr);

    load_psw(env, mask, addr);

}

#define VIRTIO_SUBCODE_64 0x0D00

static void do_ext_interrupt(CPUS390XState *env)

{

    uint64_t mask, addr;

    LowCore *lowcore;

    hwaddr len = TARGET_PAGE_SIZE;

    ExtQueue *q;

    if (!(env->psw.mask & PSW_MASK_EXT)) {

        cpu_abort(env, "Ext int w/o ext mask\n");

    }

    if (env->ext_index < 0 || env->ext_index > MAX_EXT_QUEUE) {

        cpu_abort(env, "Ext queue overrun: %d\n", env->ext_index);

    }

    q = &env->ext_queue[env->ext_index];

    lowcore = cpu_physical_memory_map(env->psa, &len, 1);

    lowcore->ext_int_code = cpu_to_be16(q->code);

    lowcore->ext_params = cpu_to_be32(q->param);

    lowcore->ext_params2 = cpu_to_be64(q->param64);

    lowcore->external_old_psw.mask = cpu_to_be64(get_psw_mask(env));

    lowcore->external_old_psw.addr = cpu_to_be64(env->psw.addr);

    lowcore->cpu_addr = cpu_to_be16(env->cpu_num | VIRTIO_SUBCODE_64);

    mask = be64_to_cpu(lowcore->external_new_psw.mask);

    addr = be64_to_cpu(lowcore->external_new_psw.addr);

    cpu_physical_memory_unmap(lowcore, len, 1, len);

    env->ext_index--;

    if (env->ext_index == -1) {

        env->pending_int &= ~INTERRUPT_EXT;

    }

    DPRINTF("%s: %" PRIx64 " %" PRIx64 "\n", __func__,

            env->psw.mask, env->psw.addr);

    load_psw(env, mask, addr);

}

void do_interrupt(CPUS390XState *env)

{

    qemu_log_mask(CPU_LOG_INT, "%s: %d at pc=%" PRIx64 "\n",

                  __func__, env->exception_index, env->psw.addr);

    s390_add_running_cpu(env);

    /* handle external interrupts */

    if ((env->psw.mask & PSW_MASK_EXT) &&

        env->exception_index == -1) {

        if (env->pending_int & INTERRUPT_EXT) {

            /* code is already in env */

            env->exception_index = EXCP_EXT;

        } else if (env->pending_int & INTERRUPT_TOD) {

            cpu_inject_ext(env, 0x1004, 0, 0);

            env->exception_index = EXCP_EXT;

            env->pending_int &= ~INTERRUPT_EXT;

            env->pending_int &= ~INTERRUPT_TOD;

        } else if (env->pending_int & INTERRUPT_CPUTIMER) {

            cpu_inject_ext(env, 0x1005, 0, 0);

            env->exception_index = EXCP_EXT;

            env->pending_int &= ~INTERRUPT_EXT;

            env->pending_int &= ~INTERRUPT_TOD;

        }

    }

    switch (env->exception_index) {

    case EXCP_PGM:

        do_program_interrupt(env);

        break;

    case EXCP_SVC:

        do_svc_interrupt(env);

        break;

    case EXCP_EXT:

        do_ext_interrupt(env);

        break;

    }

    env->exception_index = -1;

    if (!env->pending_int) {

        env->interrupt_request &= ~CPU_INTERRUPT_HARD;

    }

}

#endif /* CONFIG_USER_ONLY */