#include "sysemu/sysemu.h"
#include "cpu.h"
#include "helper_regs.h"
#include "hw/ppc/spapr.h"
#include "mmu-hash64.h"

static target_ulong compute_tlbie_rb(target_ulong v, target_ulong r,
                                     target_ulong pte_index)
{
    target_ulong rb, va_low;

    rb = (v & ~0x7fULL) << 16; /* AVA field */
    va_low = pte_index >> 3;
    if (v & HPTE64_V_SECONDARY) {
        va_low = ~va_low;
    }
    /* xor vsid from AVA */
    if (!(v & HPTE64_V_1TB_SEG)) {
        va_low ^= v >> 12;
    } else {
        va_low ^= v >> 24;
    }
    va_low &= 0x7ff;
    if (v & HPTE64_V_LARGE) {
        rb |= 1;                         /* L field */
#if 0 /* Disable that P7 specific bit for now */
        if (r & 0xff000) {
            /* non-16MB large page, must be 64k */
            /* (masks depend on page size) */
            rb |= 0x1000;                /* page encoding in LP field */
            rb |= (va_low & 0x7f) << 16; /* 7b of VA in AVA/LP field */
            rb |= (va_low & 0xfe);       /* AVAL field */
        }
#endif
    } else {
        /* 4kB page */
        rb |= (va_low & 0x7ff) << 12;   /* remaining 11b of AVA */
    }
    rb |= (v >> 54) & 0x300;            /* B field */
    return rb;
}

static target_ulong h_enter(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                            target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    target_ulong flags = args[0];
    target_ulong pte_index = args[1];
    target_ulong pteh = args[2];
    target_ulong ptel = args[3];
    target_ulong page_shift = 12;
    target_ulong raddr;
    target_ulong i;
    hwaddr hpte;

    /* only handle 4k and 16M pages for now */
    if (pteh & HPTE64_V_LARGE) {
#if 0 /* We don't support 64k pages yet */
        if ((ptel & 0xf000) == 0x1000) {
            /* 64k page */
        } else
#endif
        if ((ptel & 0xff000) == 0) {
            /* 16M page */
            page_shift = 24;
            /* lowest AVA bit must be 0 for 16M pages */
            if (pteh & 0x80) {
                return H_PARAMETER;
            }
        } else {
            return H_PARAMETER;
        }
    }

    raddr = (ptel & HPTE64_R_RPN) & ~((1ULL << page_shift) - 1);

    if (raddr < spapr->ram_limit) {
        /* Regular RAM - should have WIMG=0010 */
        if ((ptel & HPTE64_R_WIMG) != HPTE64_R_M) {
            return H_PARAMETER;
        }
    } else {
        /* Looks like an IO address */
        /* FIXME: What WIMG combinations could be sensible for IO?
         * For now we allow WIMG=010x, but are there others? */
        /* FIXME: Should we check against registered IO addresses? */
        if ((ptel & (HPTE64_R_W | HPTE64_R_I | HPTE64_R_M)) != HPTE64_R_I) {
            return H_PARAMETER;
        }
    }

    pteh &= ~0x60ULL;

    if ((pte_index * HASH_PTE_SIZE_64) & ~env->htab_mask) {
        return H_PARAMETER;
    }
    if (likely((flags & H_EXACT) == 0)) {
        pte_index &= ~7ULL;
        hpte = pte_index * HASH_PTE_SIZE_64;
        for (i = 0; ; ++i) {
            if (i == 8) {
                return H_PTEG_FULL;
            }
            if ((ppc_hash64_load_hpte0(env, hpte) & HPTE64_V_VALID) == 0) {
                break;
            }
            hpte += HASH_PTE_SIZE_64;
        }
    } else {
        i = 0;
        hpte = pte_index * HASH_PTE_SIZE_64;
        if (ppc_hash64_load_hpte0(env, hpte) & HPTE64_V_VALID) {
            return H_PTEG_FULL;
        }
    }
    ppc_hash64_store_hpte1(env, hpte, ptel);
    /* eieio();  FIXME: need some sort of barrier for smp? */
    ppc_hash64_store_hpte0(env, hpte, pteh);

    args[0] = pte_index + i;
    return H_SUCCESS;
}

enum {
    REMOVE_SUCCESS = 0,
    REMOVE_NOT_FOUND = 1,
    REMOVE_PARM = 2,
    REMOVE_HW = 3,
};

static target_ulong remove_hpte(CPUPPCState *env, target_ulong ptex,
                                target_ulong avpn,
                                target_ulong flags,
                                target_ulong *vp, target_ulong *rp)
{
    hwaddr hpte;
    target_ulong v, r, rb;

    if ((ptex * HASH_PTE_SIZE_64) & ~env->htab_mask) {
        return REMOVE_PARM;
    }

    hpte = ptex * HASH_PTE_SIZE_64;

    v = ppc_hash64_load_hpte0(env, hpte);
    r = ppc_hash64_load_hpte1(env, hpte);

    if ((v & HPTE64_V_VALID) == 0 ||
        ((flags & H_AVPN) && (v & ~0x7fULL) != avpn) ||
        ((flags & H_ANDCOND) && (v & avpn) != 0)) {
        return REMOVE_NOT_FOUND;
    }
    *vp = v;
    *rp = r;
    ppc_hash64_store_hpte0(env, hpte, 0);
    rb = compute_tlbie_rb(v, r, ptex);
    ppc_tlb_invalidate_one(env, rb);
    return REMOVE_SUCCESS;
}

static target_ulong h_remove(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                             target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    target_ulong flags = args[0];
    target_ulong pte_index = args[1];
    target_ulong avpn = args[2];
    int ret;

    ret = remove_hpte(env, pte_index, avpn, flags,
                      &args[0], &args[1]);

    switch (ret) {
    case REMOVE_SUCCESS:
        return H_SUCCESS;

    case REMOVE_NOT_FOUND:
        return H_NOT_FOUND;

    case REMOVE_PARM:
        return H_PARAMETER;

    case REMOVE_HW:
        return H_HARDWARE;
    }

    assert(0);
}

#define H_BULK_REMOVE_TYPE             0xc000000000000000ULL
#define   H_BULK_REMOVE_REQUEST        0x4000000000000000ULL
#define   H_BULK_REMOVE_RESPONSE       0x8000000000000000ULL
#define   H_BULK_REMOVE_END            0xc000000000000000ULL
#define H_BULK_REMOVE_CODE             0x3000000000000000ULL
#define   H_BULK_REMOVE_SUCCESS        0x0000000000000000ULL
#define   H_BULK_REMOVE_NOT_FOUND      0x1000000000000000ULL
#define   H_BULK_REMOVE_PARM           0x2000000000000000ULL
#define   H_BULK_REMOVE_HW             0x3000000000000000ULL
#define H_BULK_REMOVE_RC               0x0c00000000000000ULL
#define H_BULK_REMOVE_FLAGS            0x0300000000000000ULL
#define   H_BULK_REMOVE_ABSOLUTE       0x0000000000000000ULL
#define   H_BULK_REMOVE_ANDCOND        0x0100000000000000ULL
#define   H_BULK_REMOVE_AVPN           0x0200000000000000ULL
#define H_BULK_REMOVE_PTEX             0x00ffffffffffffffULL

#define H_BULK_REMOVE_MAX_BATCH        4

static target_ulong h_bulk_remove(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                  target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    int i;

    for (i = 0; i < H_BULK_REMOVE_MAX_BATCH; i++) {
        target_ulong *tsh = &args[i*2];
        target_ulong tsl = args[i*2 + 1];
        target_ulong v, r, ret;

        if ((*tsh & H_BULK_REMOVE_TYPE) == H_BULK_REMOVE_END) {
            break;
        } else if ((*tsh & H_BULK_REMOVE_TYPE) != H_BULK_REMOVE_REQUEST) {
            return H_PARAMETER;
        }

        *tsh &= H_BULK_REMOVE_PTEX | H_BULK_REMOVE_FLAGS;
        *tsh |= H_BULK_REMOVE_RESPONSE;

        if ((*tsh & H_BULK_REMOVE_ANDCOND) && (*tsh & H_BULK_REMOVE_AVPN)) {
            *tsh |= H_BULK_REMOVE_PARM;
            return H_PARAMETER;
        }

        ret = remove_hpte(env, *tsh & H_BULK_REMOVE_PTEX, tsl,
                          (*tsh & H_BULK_REMOVE_FLAGS) >> 26,
                          &v, &r);

        *tsh |= ret << 60;

        switch (ret) {
        case REMOVE_SUCCESS:
            *tsh |= (r & (HPTE64_R_C | HPTE64_R_R)) << 43;
            break;

        case REMOVE_PARM:
            return H_PARAMETER;

        case REMOVE_HW:
            return H_HARDWARE;
        }
    }

    return H_SUCCESS;
}

static target_ulong h_protect(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                              target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    target_ulong flags = args[0];
    target_ulong pte_index = args[1];
    target_ulong avpn = args[2];
    hwaddr hpte;
    target_ulong v, r, rb;

    if ((pte_index * HASH_PTE_SIZE_64) & ~env->htab_mask) {
        return H_PARAMETER;
    }

    hpte = pte_index * HASH_PTE_SIZE_64;

    v = ppc_hash64_load_hpte0(env, hpte);
    r = ppc_hash64_load_hpte1(env, hpte);

    if ((v & HPTE64_V_VALID) == 0 ||
        ((flags & H_AVPN) && (v & ~0x7fULL) != avpn)) {
        return H_NOT_FOUND;
    }

    r &= ~(HPTE64_R_PP0 | HPTE64_R_PP | HPTE64_R_N |
           HPTE64_R_KEY_HI | HPTE64_R_KEY_LO);
    r |= (flags << 55) & HPTE64_R_PP0;
    r |= (flags << 48) & HPTE64_R_KEY_HI;
    r |= flags & (HPTE64_R_PP | HPTE64_R_N | HPTE64_R_KEY_LO);
    rb = compute_tlbie_rb(v, r, pte_index);
    ppc_hash64_store_hpte0(env, hpte, v & ~HPTE64_V_VALID);
    ppc_tlb_invalidate_one(env, rb);
    ppc_hash64_store_hpte1(env, hpte, r);
    /* Don't need a memory barrier, due to qemu's global lock */
    ppc_hash64_store_hpte0(env, hpte, v);
    return H_SUCCESS;
}

static target_ulong h_read(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                           target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    target_ulong flags = args[0];
    target_ulong pte_index = args[1];
    uint8_t *hpte;
    int i, ridx, n_entries = 1;

    if ((pte_index * HASH_PTE_SIZE_64) & ~env->htab_mask) {
        return H_PARAMETER;
    }

    if (flags & H_READ_4) {
        /* Clear the two low order bits */
        pte_index &= ~(3ULL);
        n_entries = 4;
    }

    hpte = env->external_htab + (pte_index * HASH_PTE_SIZE_64);

    for (i = 0, ridx = 0; i < n_entries; i++) {
        args[ridx++] = ldq_p(hpte);
        args[ridx++] = ldq_p(hpte + (HASH_PTE_SIZE_64/2));
        hpte += HASH_PTE_SIZE_64;
    }

    return H_SUCCESS;
}

static target_ulong h_set_dabr(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                               target_ulong opcode, target_ulong *args)
{
    /* FIXME: actually implement this */
    return H_HARDWARE;
}

#define FLAGS_REGISTER_VPA         0x0000200000000000ULL
#define FLAGS_REGISTER_DTL         0x0000400000000000ULL
#define FLAGS_REGISTER_SLBSHADOW   0x0000600000000000ULL
#define FLAGS_DEREGISTER_VPA       0x0000a00000000000ULL
#define FLAGS_DEREGISTER_DTL       0x0000c00000000000ULL
#define FLAGS_DEREGISTER_SLBSHADOW 0x0000e00000000000ULL

#define VPA_MIN_SIZE           640
#define VPA_SIZE_OFFSET        0x4
#define VPA_SHARED_PROC_OFFSET 0x9
#define VPA_SHARED_PROC_VAL    0x2

static target_ulong register_vpa(CPUPPCState *env, target_ulong vpa)
{
    uint16_t size;
    uint8_t tmp;

    if (vpa == 0) {
        hcall_dprintf("Can't cope with registering a VPA at logical 0\n");
        return H_HARDWARE;
    }

    if (vpa % env->dcache_line_size) {
        return H_PARAMETER;
    }
    /* FIXME: bounds check the address */

    size = lduw_be_phys(vpa + 0x4);

    if (size < VPA_MIN_SIZE) {
        return H_PARAMETER;
    }

    /* VPA is not allowed to cross a page boundary */
    if ((vpa / 4096) != ((vpa + size - 1) / 4096)) {
        return H_PARAMETER;
    }

    env->vpa_addr = vpa;

    tmp = ldub_phys(env->vpa_addr + VPA_SHARED_PROC_OFFSET);
    tmp |= VPA_SHARED_PROC_VAL;
    stb_phys(env->vpa_addr + VPA_SHARED_PROC_OFFSET, tmp);

    return H_SUCCESS;
}

static target_ulong deregister_vpa(CPUPPCState *env, target_ulong vpa)
{
    if (env->slb_shadow_addr) {
        return H_RESOURCE;
    }

    if (env->dtl_addr) {
        return H_RESOURCE;
    }

    env->vpa_addr = 0;
    return H_SUCCESS;
}

static target_ulong register_slb_shadow(CPUPPCState *env, target_ulong addr)
{
    uint32_t size;

    if (addr == 0) {
        hcall_dprintf("Can't cope with SLB shadow at logical 0\n");
        return H_HARDWARE;
    }

    size = ldl_be_phys(addr + 0x4);
    if (size < 0x8) {
        return H_PARAMETER;
    }

    if ((addr / 4096) != ((addr + size - 1) / 4096)) {
        return H_PARAMETER;
    }

    if (!env->vpa_addr) {
        return H_RESOURCE;
    }

    env->slb_shadow_addr = addr;
    env->slb_shadow_size = size;

    return H_SUCCESS;
}

static target_ulong deregister_slb_shadow(CPUPPCState *env, target_ulong addr)
{
    env->slb_shadow_addr = 0;
    env->slb_shadow_size = 0;
    return H_SUCCESS;
}

static target_ulong register_dtl(CPUPPCState *env, target_ulong addr)
{
    uint32_t size;

    if (addr == 0) {
        hcall_dprintf("Can't cope with DTL at logical 0\n");
        return H_HARDWARE;
    }

    size = ldl_be_phys(addr + 0x4);

    if (size < 48) {
        return H_PARAMETER;
    }

    if (!env->vpa_addr) {
        return H_RESOURCE;
    }

    env->dtl_addr = addr;
    env->dtl_size = size;

    return H_SUCCESS;
}

static target_ulong deregister_dtl(CPUPPCState *env, target_ulong addr)
{
    env->dtl_addr = 0;
    env->dtl_size = 0;

    return H_SUCCESS;
}

static target_ulong h_register_vpa(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                   target_ulong opcode, target_ulong *args)
{
    target_ulong flags = args[0];
    target_ulong procno = args[1];
    target_ulong vpa = args[2];
    target_ulong ret = H_PARAMETER;
    CPUPPCState *tenv;
    CPUState *tcpu;

    tcpu = qemu_get_cpu(procno);
    if (!tcpu) {
        return H_PARAMETER;
    }
    tenv = tcpu->env_ptr;

    switch (flags) {
    case FLAGS_REGISTER_VPA:
        ret = register_vpa(tenv, vpa);
        break;

    case FLAGS_DEREGISTER_VPA:
        ret = deregister_vpa(tenv, vpa);
        break;

    case FLAGS_REGISTER_SLBSHADOW:
        ret = register_slb_shadow(tenv, vpa);
        break;

    case FLAGS_DEREGISTER_SLBSHADOW:
        ret = deregister_slb_shadow(tenv, vpa);
        break;

    case FLAGS_REGISTER_DTL:
        ret = register_dtl(tenv, vpa);
        break;

    case FLAGS_DEREGISTER_DTL:
        ret = deregister_dtl(tenv, vpa);
        break;
    }

    return ret;
}

static target_ulong h_cede(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                           target_ulong opcode, target_ulong *args)
{
    CPUPPCState *env = &cpu->env;
    CPUState *cs = CPU(cpu);

    env->msr |= (1ULL << MSR_EE);
    hreg_compute_hflags(env);
    if (!cpu_has_work(cs)) {
        cs->halted = 1;
        env->exception_index = EXCP_HLT;
        cs->exit_request = 1;
    }
    return H_SUCCESS;
}

static target_ulong h_rtas(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                           target_ulong opcode, target_ulong *args)
{
    target_ulong rtas_r3 = args[0];
    uint32_t token = ldl_be_phys(rtas_r3);
    uint32_t nargs = ldl_be_phys(rtas_r3 + 4);
    uint32_t nret = ldl_be_phys(rtas_r3 + 8);

    return spapr_rtas_call(spapr, token, nargs, rtas_r3 + 12,
                           nret, rtas_r3 + 12 + 4*nargs);
}

static target_ulong h_logical_load(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                   target_ulong opcode, target_ulong *args)
{
    target_ulong size = args[0];
    target_ulong addr = args[1];

    switch (size) {
    case 1:
        args[0] = ldub_phys(addr);
        return H_SUCCESS;
    case 2:
        args[0] = lduw_phys(addr);
        return H_SUCCESS;
    case 4:
        args[0] = ldl_phys(addr);
        return H_SUCCESS;
    case 8:
        args[0] = ldq_phys(addr);
        return H_SUCCESS;
    }
    return H_PARAMETER;
}

static target_ulong h_logical_store(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                    target_ulong opcode, target_ulong *args)
{
    target_ulong size = args[0];
    target_ulong addr = args[1];
    target_ulong val  = args[2];

    switch (size) {
    case 1:
        stb_phys(addr, val);
        return H_SUCCESS;
    case 2:
        stw_phys(addr, val);
        return H_SUCCESS;
    case 4:
        stl_phys(addr, val);
        return H_SUCCESS;
    case 8:
        stq_phys(addr, val);
        return H_SUCCESS;
    }
    return H_PARAMETER;
}

static target_ulong h_logical_memop(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                    target_ulong opcode, target_ulong *args)
{
    target_ulong dst   = args[0]; /* Destination address */
    target_ulong src   = args[1]; /* Source address */
    target_ulong esize = args[2]; /* Element size (0=1,1=2,2=4,3=8) */
    target_ulong count = args[3]; /* Element count */
    target_ulong op    = args[4]; /* 0 = copy, 1 = invert */
    uint64_t tmp;
    unsigned int mask = (1 << esize) - 1;
    int step = 1 << esize;

    if (count > 0x80000000) {
        return H_PARAMETER;
    }

    if ((dst & mask) || (src & mask) || (op > 1)) {
        return H_PARAMETER;
    }

    if (dst >= src && dst < (src + (count << esize))) {
            dst = dst + ((count - 1) << esize);
            src = src + ((count - 1) << esize);
            step = -step;
    }

    while (count--) {
        switch (esize) {
        case 0:
            tmp = ldub_phys(src);
            break;
        case 1:
            tmp = lduw_phys(src);
            break;
        case 2:
            tmp = ldl_phys(src);
            break;
        case 3:
            tmp = ldq_phys(src);
            break;
        default:
            return H_PARAMETER;
        }
        if (op == 1) {
            tmp = ~tmp;
        }
        switch (esize) {
        case 0:
            stb_phys(dst, tmp);
            break;
        case 1:
            stw_phys(dst, tmp);
            break;
        case 2:
            stl_phys(dst, tmp);
            break;
        case 3:
            stq_phys(dst, tmp);
            break;
        }
        dst = dst + step;
        src = src + step;
    }

    return H_SUCCESS;
}

static target_ulong h_logical_icbi(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                   target_ulong opcode, target_ulong *args)
{
    /* Nothing to do on emulation, KVM will trap this in the kernel */
    return H_SUCCESS;
}

static target_ulong h_logical_dcbf(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                   target_ulong opcode, target_ulong *args)
{
    /* Nothing to do on emulation, KVM will trap this in the kernel */
    return H_SUCCESS;
}

static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1];
static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX - KVMPPC_HCALL_BASE + 1];

void spapr_register_hypercall(target_ulong opcode, spapr_hcall_fn fn)
{
    spapr_hcall_fn *slot;

    if (opcode <= MAX_HCALL_OPCODE) {
        assert((opcode & 0x3) == 0);

        slot = &papr_hypercall_table[opcode / 4];
    } else {
        assert((opcode >= KVMPPC_HCALL_BASE) && (opcode <= KVMPPC_HCALL_MAX));

        slot = &kvmppc_hypercall_table[opcode - KVMPPC_HCALL_BASE];
    }

    assert(!(*slot));
    *slot = fn;
}

target_ulong spapr_hypercall(PowerPCCPU *cpu, target_ulong opcode,
                             target_ulong *args)
{
    if ((opcode <= MAX_HCALL_OPCODE)
        && ((opcode & 0x3) == 0)) {
        spapr_hcall_fn fn = papr_hypercall_table[opcode / 4];

        if (fn) {
            return fn(cpu, spapr, opcode, args);
        }
    } else if ((opcode >= KVMPPC_HCALL_BASE) &&
               (opcode <= KVMPPC_HCALL_MAX)) {
        spapr_hcall_fn fn = kvmppc_hypercall_table[opcode - KVMPPC_HCALL_BASE];

        if (fn) {
            return fn(cpu, spapr, opcode, args);
        }
    }

    hcall_dprintf("Unimplemented hcall 0x" TARGET_FMT_lx "\n", opcode);
    return H_FUNCTION;
}

static void hypercall_register_types(void)
{
    /* hcall-pft */
    spapr_register_hypercall(H_ENTER, h_enter);
    spapr_register_hypercall(H_REMOVE, h_remove);
    spapr_register_hypercall(H_PROTECT, h_protect);
    spapr_register_hypercall(H_READ, h_read);

    /* hcall-bulk */
    spapr_register_hypercall(H_BULK_REMOVE, h_bulk_remove);

    /* hcall-dabr */
    spapr_register_hypercall(H_SET_DABR, h_set_dabr);

    /* hcall-splpar */
    spapr_register_hypercall(H_REGISTER_VPA, h_register_vpa);
    spapr_register_hypercall(H_CEDE, h_cede);

    /* "debugger" hcalls (also used by SLOF). Note: We do -not- differenciate
     * here between the "CI" and the "CACHE" variants, they will use whatever
     * mapping attributes qemu is using. When using KVM, the kernel will
     * enforce the attributes more strongly
     */
    spapr_register_hypercall(H_LOGICAL_CI_LOAD, h_logical_load);
    spapr_register_hypercall(H_LOGICAL_CI_STORE, h_logical_store);
    spapr_register_hypercall(H_LOGICAL_CACHE_LOAD, h_logical_load);
    spapr_register_hypercall(H_LOGICAL_CACHE_STORE, h_logical_store);
    spapr_register_hypercall(H_LOGICAL_ICBI, h_logical_icbi);
    spapr_register_hypercall(H_LOGICAL_DCBF, h_logical_dcbf);
    spapr_register_hypercall(KVMPPC_H_LOGICAL_MEMOP, h_logical_memop);

    /* qemu/KVM-PPC specific hcalls */
    spapr_register_hypercall(KVMPPC_H_RTAS, h_rtas);
}

type_init(hypercall_register_types)