mem_helper.c

/*
 *  S/390 memory access 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 "qemu/osdep.h"
#include "cpu.h"
#include "exec/address-spaces.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "qemu/int128.h"

#if !defined(CONFIG_USER_ONLY)
#include "hw/s390x/storage-keys.h"
#endif

/*****************************************************************************/
/* Softmmu support */
#if !defined(CONFIG_USER_ONLY)

/* try to fill the TLB and return an exception if error. If retaddr is
   NULL, it means that the function was called in C code (i.e. not
   from generated code or from helper.c) */
/* XXX: fix it to restore all registers */
void tlb_fill(CPUState *cs, target_ulong addr, MMUAccessType access_type,
              int mmu_idx, uintptr_t retaddr)
{
    int ret = s390_cpu_handle_mmu_fault(cs, addr, access_type, mmu_idx);
    if (unlikely(ret != 0)) {
        cpu_loop_exit_restore(cs, retaddr);
    }
}

#endif

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

/* Reduce the length so that addr + len doesn't cross a page boundary.  */
static inline uint32_t adj_len_to_page(uint32_t len, uint64_t addr)
{
#ifndef CONFIG_USER_ONLY
    if ((addr & ~TARGET_PAGE_MASK) + len - 1 >= TARGET_PAGE_SIZE) {
        return -addr & ~TARGET_PAGE_MASK;
    }
#endif
    return len;
}

static void fast_memset(CPUS390XState *env, uint64_t dest, uint8_t byte,
                        uint32_t l, uintptr_t ra)
{
    int mmu_idx = cpu_mmu_index(env, false);

    while (l > 0) {
        void *p = tlb_vaddr_to_host(env, dest, MMU_DATA_STORE, mmu_idx);
        if (p) {
            /* Access to the whole page in write mode granted.  */
            uint32_t l_adj = adj_len_to_page(l, dest);
            memset(p, byte, l_adj);
            dest += l_adj;
            l -= l_adj;
        } else {
            /* We failed to get access to the whole page. The next write
               access will likely fill the QEMU TLB for the next iteration.  */
            cpu_stb_data_ra(env, dest, byte, ra);
            dest++;
            l--;
        }
    }
}

static void fast_memmove(CPUS390XState *env, uint64_t dest, uint64_t src,
                         uint32_t l, uintptr_t ra)
{
    int mmu_idx = cpu_mmu_index(env, false);

    while (l > 0) {
        void *src_p = tlb_vaddr_to_host(env, src, MMU_DATA_LOAD, mmu_idx);
        void *dest_p = tlb_vaddr_to_host(env, dest, MMU_DATA_STORE, mmu_idx);
        if (src_p && dest_p) {
            /* Access to both whole pages granted.  */
            uint32_t l_adj = adj_len_to_page(l, src);
            l_adj = adj_len_to_page(l_adj, dest);
            memmove(dest_p, src_p, l_adj);
            src += l_adj;
            dest += l_adj;
            l -= l_adj;
        } else {
            /* We failed to get access to one or both whole pages. The next
               read or write access will likely fill the QEMU TLB for the
               next iteration.  */
            cpu_stb_data_ra(env, dest, cpu_ldub_data_ra(env, src, ra), ra);
            src++;
            dest++;
            l--;
        }
    }
}

/* and on array */
static uint32_t do_helper_nc(CPUS390XState *env, uint32_t l, uint64_t dest,
                             uint64_t src, uintptr_t ra)
{
    uint32_t i;
    uint8_t c = 0;

    HELPER_LOG("%s l %d dest %" PRIx64 " src %" PRIx64 "\n",
               __func__, l, dest, src);

    for (i = 0; i <= l; i++) {
        uint8_t x = cpu_ldub_data_ra(env, src + i, ra);
        x &= cpu_ldub_data_ra(env, dest + i, ra);
        c |= x;
        cpu_stb_data_ra(env, dest + i, x, ra);
    }
    return c != 0;
}

uint32_t HELPER(nc)(CPUS390XState *env, uint32_t l, uint64_t dest,
                    uint64_t src)
{
    return do_helper_nc(env, l, dest, src, GETPC());
}

/* xor on array */
static uint32_t do_helper_xc(CPUS390XState *env, uint32_t l, uint64_t dest,
                             uint64_t src, uintptr_t ra)
{
    uint32_t i;
    uint8_t c = 0;

    HELPER_LOG("%s l %d dest %" PRIx64 " src %" PRIx64 "\n",
               __func__, l, dest, src);

    /* xor with itself is the same as memset(0) */
    if (src == dest) {
        fast_memset(env, dest, 0, l + 1, ra);
        return 0;
    }

    for (i = 0; i <= l; i++) {
        uint8_t x = cpu_ldub_data_ra(env, src + i, ra);
        x ^= cpu_ldub_data_ra(env, dest + i, ra);
        c |= x;
        cpu_stb_data_ra(env, dest + i, x, ra);
    }
    return c != 0;
}

uint32_t HELPER(xc)(CPUS390XState *env, uint32_t l, uint64_t dest,
                    uint64_t src)
{
    return do_helper_xc(env, l, dest, src, GETPC());
}

/* or on array */
static uint32_t do_helper_oc(CPUS390XState *env, uint32_t l, uint64_t dest,
                             uint64_t src, uintptr_t ra)
{
    uint32_t i;
    uint8_t c = 0;

    HELPER_LOG("%s l %d dest %" PRIx64 " src %" PRIx64 "\n",
               __func__, l, dest, src);

    for (i = 0; i <= l; i++) {
        uint8_t x = cpu_ldub_data_ra(env, src + i, ra);
        x |= cpu_ldub_data_ra(env, dest + i, ra);
        c |= x;
        cpu_stb_data_ra(env, dest + i, x, ra);
    }
    return c != 0;
}

uint32_t HELPER(oc)(CPUS390XState *env, uint32_t l, uint64_t dest,
                    uint64_t src)
{
    return do_helper_oc(env, l, dest, src, GETPC());
}

/* memmove */
static uint32_t do_helper_mvc(CPUS390XState *env, uint32_t l, uint64_t dest,
                              uint64_t src, uintptr_t ra)
{
    uint32_t i;

    HELPER_LOG("%s l %d dest %" PRIx64 " src %" PRIx64 "\n",
               __func__, l, dest, src);

    /* mvc and memmove do not behave the same when areas overlap! */
    /* mvc with source pointing to the byte after the destination is the
       same as memset with the first source byte */
    if (dest == src + 1) {
        fast_memset(env, dest, cpu_ldub_data_ra(env, src, ra), l + 1, ra);
    } else if (dest < src || src + l < dest) {
        fast_memmove(env, dest, src, l + 1, ra);
    } else {
        /* slow version with byte accesses which always work */
        for (i = 0; i <= l; i++) {
            uint8_t x = cpu_ldub_data_ra(env, src + i, ra);
            cpu_stb_data_ra(env, dest + i, x, ra);
        }
    }

    return env->cc_op;
}

void HELPER(mvc)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
{
    do_helper_mvc(env, l, dest, src, GETPC());
}

/* move inverse  */
void HELPER(mvcin)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
{
    uintptr_t ra = GETPC();
    int i;

    for (i = 0; i <= l; i++) {
        uint8_t v = cpu_ldub_data_ra(env, src - i, ra);
        cpu_stb_data_ra(env, dest + i, v, ra);
    }
}

/* move numerics  */
void HELPER(mvn)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
{
    uintptr_t ra = GETPC();
    int i;

    for (i = 0; i <= l; i++) {
        uint8_t v = cpu_ldub_data_ra(env, dest + i, ra) & 0xf0;
        v |= cpu_ldub_data_ra(env, src + i, ra) & 0x0f;
        cpu_stb_data_ra(env, dest + i, v, ra);
    }
}

/* compare unsigned byte arrays */
static uint32_t do_helper_clc(CPUS390XState *env, uint32_t l, uint64_t s1,
                              uint64_t s2, uintptr_t ra)
{
    uint32_t i;
    uint32_t cc = 0;

    HELPER_LOG("%s l %d s1 %" PRIx64 " s2 %" PRIx64 "\n",
               __func__, l, s1, s2);

    for (i = 0; i <= l; i++) {
        uint8_t x = cpu_ldub_data_ra(env, s1 + i, ra);
        uint8_t y = cpu_ldub_data_ra(env, s2 + i, ra);
        HELPER_LOG("%02x (%c)/%02x (%c) ", x, x, y, y);
        if (x < y) {
            cc = 1;
            break;
        } else if (x > y) {
            cc = 2;
            break;
        }
    }

    HELPER_LOG("\n");
    return cc;
}

uint32_t HELPER(clc)(CPUS390XState *env, uint32_t l, uint64_t s1, uint64_t s2)
{
    return do_helper_clc(env, l, s1, s2, GETPC());
}

/* compare logical under mask */
uint32_t HELPER(clm)(CPUS390XState *env, uint32_t r1, uint32_t mask,
                     uint64_t addr)
{
    uintptr_t ra = GETPC();
    uint32_t cc = 0;

    HELPER_LOG("%s: r1 0x%x mask 0x%x addr 0x%" PRIx64 "\n", __func__, r1,
               mask, addr);

    while (mask) {
        if (mask & 8) {
            uint8_t d = cpu_ldub_data_ra(env, addr, ra);
            uint8_t r = extract32(r1, 24, 8);
            HELPER_LOG("mask 0x%x %02x/%02x (0x%" PRIx64 ") ", mask, r, d,
                       addr);
            if (r < d) {
                cc = 1;
                break;
            } else if (r > d) {
                cc = 2;
                break;
            }
            addr++;
        }
        mask = (mask << 1) & 0xf;
        r1 <<= 8;
    }

    HELPER_LOG("\n");
    return cc;
}

static inline uint64_t fix_address(CPUS390XState *env, uint64_t a)
{
    /* 31-Bit mode */
    if (!(env->psw.mask & PSW_MASK_64)) {
        a &= 0x7fffffff;
    }
    return a;
}

static inline uint64_t get_address(CPUS390XState *env, int x2, int b2, int d2)
{
    uint64_t r = d2;
    if (x2) {
        r += env->regs[x2];
    }
    if (b2) {
        r += env->regs[b2];
    }
    return fix_address(env, r);
}

static inline uint64_t get_address_31fix(CPUS390XState *env, int reg)
{
    return fix_address(env, env->regs[reg]);
}

/* search string (c is byte to search, r2 is string, r1 end of string) */
uint64_t HELPER(srst)(CPUS390XState *env, uint64_t r0, uint64_t end,
                      uint64_t str)
{
    uintptr_t ra = GETPC();
    uint32_t len;
    uint8_t v, c = r0;

    str = fix_address(env, str);
    end = fix_address(env, end);

    /* Assume for now that R2 is unmodified.  */
    env->retxl = str;

    /* Lest we fail to service interrupts in a timely manner, limit the
       amount of work we're willing to do.  For now, let's cap at 8k.  */
    for (len = 0; len < 0x2000; ++len) {
        if (str + len == end) {
            /* Character not found.  R1 & R2 are unmodified.  */
            env->cc_op = 2;
            return end;
        }
        v = cpu_ldub_data_ra(env, str + len, ra);
        if (v == c) {
            /* Character found.  Set R1 to the location; R2 is unmodified.  */
            env->cc_op = 1;
            return str + len;
        }
    }

    /* CPU-determined bytes processed.  Advance R2 to next byte to process.  */
    env->retxl = str + len;
    env->cc_op = 3;
    return end;
}

/* unsigned string compare (c is string terminator) */
uint64_t HELPER(clst)(CPUS390XState *env, uint64_t c, uint64_t s1, uint64_t s2)
{
    uintptr_t ra = GETPC();
    uint32_t len;

    c = c & 0xff;
    s1 = fix_address(env, s1);
    s2 = fix_address(env, s2);

    /* Lest we fail to service interrupts in a timely manner, limit the
       amount of work we're willing to do.  For now, let's cap at 8k.  */
    for (len = 0; len < 0x2000; ++len) {
        uint8_t v1 = cpu_ldub_data_ra(env, s1 + len, ra);
        uint8_t v2 = cpu_ldub_data_ra(env, s2 + len, ra);
        if (v1 == v2) {
            if (v1 == c) {
                /* Equal.  CC=0, and don't advance the registers.  */
                env->cc_op = 0;
                env->retxl = s2;
                return s1;
            }
        } else {
            /* Unequal.  CC={1,2}, and advance the registers.  Note that
               the terminator need not be zero, but the string that contains
               the terminator is by definition "low".  */
            env->cc_op = (v1 == c ? 1 : v2 == c ? 2 : v1 < v2 ? 1 : 2);
            env->retxl = s2 + len;
            return s1 + len;
        }
    }

    /* CPU-determined bytes equal; advance the registers.  */
    env->cc_op = 3;
    env->retxl = s2 + len;
    return s1 + len;
}

/* move page */
uint32_t HELPER(mvpg)(CPUS390XState *env, uint64_t r0, uint64_t r1, uint64_t r2)
{
    /* ??? missing r0 handling, which includes access keys, but more
       importantly optional suppression of the exception!  */
    fast_memmove(env, r1, r2, TARGET_PAGE_SIZE, GETPC());
    return 0; /* data moved */
}

/* string copy (c is string terminator) */
uint64_t HELPER(mvst)(CPUS390XState *env, uint64_t c, uint64_t d, uint64_t s)
{
    uintptr_t ra = GETPC();
    uint32_t len;

    c = c & 0xff;
    d = fix_address(env, d);
    s = fix_address(env, s);

    /* Lest we fail to service interrupts in a timely manner, limit the
       amount of work we're willing to do.  For now, let's cap at 8k.  */
    for (len = 0; len < 0x2000; ++len) {
        uint8_t v = cpu_ldub_data_ra(env, s + len, ra);
        cpu_stb_data_ra(env, d + len, v, ra);
        if (v == c) {
            /* Complete.  Set CC=1 and advance R1.  */
            env->cc_op = 1;
            env->retxl = s;
            return d + len;
        }
    }

    /* Incomplete.  Set CC=3 and signal to advance R1 and R2.  */
    env->cc_op = 3;
    env->retxl = s + len;
    return d + len;
}

/* load access registers r1 to r3 from memory at a2 */
void HELPER(lam)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    int i;

    for (i = r1;; i = (i + 1) % 16) {
        env->aregs[i] = cpu_ldl_data_ra(env, a2, ra);
        a2 += 4;

        if (i == r3) {
            break;
        }
    }
}

/* store access registers r1 to r3 in memory at a2 */
void HELPER(stam)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    int i;

    for (i = r1;; i = (i + 1) % 16) {
        cpu_stl_data_ra(env, a2, env->aregs[i], ra);
        a2 += 4;

        if (i == r3) {
            break;
        }
    }
}

/* move long */
uint32_t HELPER(mvcl)(CPUS390XState *env, uint32_t r1, uint32_t r2)
{
    uintptr_t ra = GETPC();
    uint64_t destlen = env->regs[r1 + 1] & 0xffffff;
    uint64_t dest = get_address_31fix(env, r1);
    uint64_t srclen = env->regs[r2 + 1] & 0xffffff;
    uint64_t src = get_address_31fix(env, r2);
    uint8_t pad = env->regs[r2 + 1] >> 24;
    uint8_t v;
    uint32_t cc;

    if (destlen == srclen) {
        cc = 0;
    } else if (destlen < srclen) {
        cc = 1;
    } else {
        cc = 2;
    }

    if (srclen > destlen) {
        srclen = destlen;
    }

    for (; destlen && srclen; src++, dest++, destlen--, srclen--) {
        v = cpu_ldub_data_ra(env, src, ra);
        cpu_stb_data_ra(env, dest, v, ra);
    }

    for (; destlen; dest++, destlen--) {
        cpu_stb_data_ra(env, dest, pad, ra);
    }

    env->regs[r1 + 1] = destlen;
    /* can't use srclen here, we trunc'ed it */
    env->regs[r2 + 1] -= src - env->regs[r2];
    env->regs[r1] = dest;
    env->regs[r2] = src;

    return cc;
}

/* move long extended another memcopy insn with more bells and whistles */
uint32_t HELPER(mvcle)(CPUS390XState *env, uint32_t r1, uint64_t a2,
                       uint32_t r3)
{
    uintptr_t ra = GETPC();
    uint64_t destlen = env->regs[r1 + 1];
    uint64_t dest = env->regs[r1];
    uint64_t srclen = env->regs[r3 + 1];
    uint64_t src = env->regs[r3];
    uint8_t pad = a2 & 0xff;
    uint8_t v;
    uint32_t cc;

    if (!(env->psw.mask & PSW_MASK_64)) {
        destlen = (uint32_t)destlen;
        srclen = (uint32_t)srclen;
        dest &= 0x7fffffff;
        src &= 0x7fffffff;
    }

    if (destlen == srclen) {
        cc = 0;
    } else if (destlen < srclen) {
        cc = 1;
    } else {
        cc = 2;
    }

    if (srclen > destlen) {
        srclen = destlen;
    }

    for (; destlen && srclen; src++, dest++, destlen--, srclen--) {
        v = cpu_ldub_data_ra(env, src, ra);
        cpu_stb_data_ra(env, dest, v, ra);
    }

    for (; destlen; dest++, destlen--) {
        cpu_stb_data_ra(env, dest, pad, ra);
    }

    env->regs[r1 + 1] = destlen;
    /* can't use srclen here, we trunc'ed it */
    /* FIXME: 31-bit mode! */
    env->regs[r3 + 1] -= src - env->regs[r3];
    env->regs[r1] = dest;
    env->regs[r3] = src;

    return cc;
}

/* compare logical long extended memcompare insn with padding */
uint32_t HELPER(clcle)(CPUS390XState *env, uint32_t r1, uint64_t a2,
                       uint32_t r3)
{
    uintptr_t ra = GETPC();
    uint64_t destlen = env->regs[r1 + 1];
    uint64_t dest = get_address_31fix(env, r1);
    uint64_t srclen = env->regs[r3 + 1];
    uint64_t src = get_address_31fix(env, r3);
    uint8_t pad = a2 & 0xff;
    uint32_t cc = 0;

    if (!(destlen || srclen)) {
        return cc;
    }

    if (srclen > destlen) {
        srclen = destlen;
    }

    for (; destlen || srclen; src++, dest++, destlen--, srclen--) {
        uint8_t v1 = srclen ? cpu_ldub_data_ra(env, src, ra) : pad;
        uint8_t v2 = destlen ? cpu_ldub_data_ra(env, dest, ra) : pad;
        if (v1 != v2) {
            cc = (v1 < v2) ? 1 : 2;
            break;
        }
    }

    env->regs[r1 + 1] = destlen;
    /* can't use srclen here, we trunc'ed it */
    env->regs[r3 + 1] -= src - env->regs[r3];
    env->regs[r1] = dest;
    env->regs[r3] = src;

    return cc;
}

/* checksum */
uint64_t HELPER(cksm)(CPUS390XState *env, uint64_t r1,
                      uint64_t src, uint64_t src_len)
{
    uintptr_t ra = GETPC();
    uint64_t max_len, len;
    uint64_t cksm = (uint32_t)r1;

    /* Lest we fail to service interrupts in a timely manner, limit the
       amount of work we're willing to do.  For now, let's cap at 8k.  */
    max_len = (src_len > 0x2000 ? 0x2000 : src_len);

    /* Process full words as available.  */
    for (len = 0; len + 4 <= max_len; len += 4, src += 4) {
        cksm += (uint32_t)cpu_ldl_data_ra(env, src, ra);
    }

    switch (max_len - len) {
    case 1:
        cksm += cpu_ldub_data_ra(env, src, ra) << 24;
        len += 1;
        break;
    case 2:
        cksm += cpu_lduw_data_ra(env, src, ra) << 16;
        len += 2;
        break;
    case 3:
        cksm += cpu_lduw_data_ra(env, src, ra) << 16;
        cksm += cpu_ldub_data_ra(env, src + 2, ra) << 8;
        len += 3;
        break;
    }

    /* Fold the carry from the checksum.  Note that we can see carry-out
       during folding more than once (but probably not more than twice).  */
    while (cksm > 0xffffffffull) {
        cksm = (uint32_t)cksm + (cksm >> 32);
    }

    /* Indicate whether or not we've processed everything.  */
    env->cc_op = (len == src_len ? 0 : 3);

    /* Return both cksm and processed length.  */
    env->retxl = cksm;
    return len;
}

void HELPER(pack)(CPUS390XState *env, uint32_t len, uint64_t dest, uint64_t src)
{
    uintptr_t ra = GETPC();
    int len_dest = len >> 4;
    int len_src = len & 0xf;
    uint8_t b;

    dest += len_dest;
    src += len_src;

    /* last byte is special, it only flips the nibbles */
    b = cpu_ldub_data_ra(env, src, ra);
    cpu_stb_data_ra(env, dest, (b << 4) | (b >> 4), ra);
    src--;
    len_src--;

    /* now pack every value */
    while (len_dest >= 0) {
        b = 0;

        if (len_src > 0) {
            b = cpu_ldub_data_ra(env, src, ra) & 0x0f;
            src--;
            len_src--;
        }
        if (len_src > 0) {
            b |= cpu_ldub_data_ra(env, src, ra) << 4;
            src--;
            len_src--;
        }

        len_dest--;
        dest--;
        cpu_stb_data_ra(env, dest, b, ra);
    }
}

void HELPER(unpk)(CPUS390XState *env, uint32_t len, uint64_t dest,
                  uint64_t src)
{
    uintptr_t ra = GETPC();
    int len_dest = len >> 4;
    int len_src = len & 0xf;
    uint8_t b;
    int second_nibble = 0;

    dest += len_dest;
    src += len_src;

    /* last byte is special, it only flips the nibbles */
    b = cpu_ldub_data_ra(env, src, ra);
    cpu_stb_data_ra(env, dest, (b << 4) | (b >> 4), ra);
    src--;
    len_src--;

    /* now pad every nibble with 0xf0 */

    while (len_dest > 0) {
        uint8_t cur_byte = 0;

        if (len_src > 0) {
            cur_byte = cpu_ldub_data_ra(env, src, ra);
        }

        len_dest--;
        dest--;

        /* only advance one nibble at a time */
        if (second_nibble) {
            cur_byte >>= 4;
            len_src--;
            src--;
        }
        second_nibble = !second_nibble;

        /* digit */
        cur_byte = (cur_byte & 0xf);
        /* zone bits */
        cur_byte |= 0xf0;

        cpu_stb_data_ra(env, dest, cur_byte, ra);
    }
}

static uint32_t do_helper_tr(CPUS390XState *env, uint32_t len, uint64_t array,
                             uint64_t trans, uintptr_t ra)
{
    uint32_t i;

    for (i = 0; i <= len; i++) {
        uint8_t byte = cpu_ldub_data_ra(env, array + i, ra);
        uint8_t new_byte = cpu_ldub_data_ra(env, trans + byte, ra);
        cpu_stb_data_ra(env, array + i, new_byte, ra);
    }

    return env->cc_op;
}

void HELPER(tr)(CPUS390XState *env, uint32_t len, uint64_t array,
                uint64_t trans)
{
    do_helper_tr(env, len, array, trans, GETPC());
}

uint64_t HELPER(tre)(CPUS390XState *env, uint64_t array,
                     uint64_t len, uint64_t trans)
{
    uintptr_t ra = GETPC();
    uint8_t end = env->regs[0] & 0xff;
    uint64_t l = len;
    uint64_t i;
    uint32_t cc = 0;

    if (!(env->psw.mask & PSW_MASK_64)) {
        array &= 0x7fffffff;
        l = (uint32_t)l;
    }

    /* Lest we fail to service interrupts in a timely manner, limit the
       amount of work we're willing to do.  For now, let's cap at 8k.  */
    if (l > 0x2000) {
        l = 0x2000;
        cc = 3;
    }

    for (i = 0; i < l; i++) {
        uint8_t byte, new_byte;

        byte = cpu_ldub_data_ra(env, array + i, ra);

        if (byte == end) {
            cc = 1;
            break;
        }

        new_byte = cpu_ldub_data_ra(env, trans + byte, ra);
        cpu_stb_data_ra(env, array + i, new_byte, ra);
    }

    env->cc_op = cc;
    env->retxl = len - i;
    return array + i;
}

static uint32_t do_helper_trt(CPUS390XState *env, uint32_t len, uint64_t array,
                              uint64_t trans, uintptr_t ra)
{
    uint32_t i;

    for (i = 0; i <= len; i++) {
        uint8_t byte = cpu_ldub_data_ra(env, array + i, ra);
        uint8_t sbyte = cpu_ldub_data_ra(env, trans + byte, ra);

        if (sbyte != 0) {
            env->regs[1] = array + i;
            env->regs[2] = deposit64(env->regs[2], 0, 8, sbyte);
            return (i == len) ? 2 : 1;
        }
    }

    return 0;
}

uint32_t HELPER(trt)(CPUS390XState *env, uint32_t len, uint64_t array,
                     uint64_t trans)
{
    return do_helper_trt(env, len, array, trans, GETPC());
}

void HELPER(cdsg)(CPUS390XState *env, uint64_t addr,
                  uint32_t r1, uint32_t r3)
{
    uintptr_t ra = GETPC();
    Int128 cmpv = int128_make128(env->regs[r1 + 1], env->regs[r1]);
    Int128 newv = int128_make128(env->regs[r3 + 1], env->regs[r3]);
    Int128 oldv;
    bool fail;

    if (parallel_cpus) {
#ifndef CONFIG_ATOMIC128
        cpu_loop_exit_atomic(ENV_GET_CPU(env), ra);
#else
        int mem_idx = cpu_mmu_index(env, false);
        TCGMemOpIdx oi = make_memop_idx(MO_TEQ | MO_ALIGN_16, mem_idx);
        oldv = helper_atomic_cmpxchgo_be_mmu(env, addr, cmpv, newv, oi, ra);
        fail = !int128_eq(oldv, cmpv);
#endif
    } else {
        uint64_t oldh, oldl;

        oldh = cpu_ldq_data_ra(env, addr + 0, ra);
        oldl = cpu_ldq_data_ra(env, addr + 8, ra);

        oldv = int128_make128(oldl, oldh);
        fail = !int128_eq(oldv, cmpv);
        if (fail) {
            newv = oldv;
        }

        cpu_stq_data_ra(env, addr + 0, int128_gethi(newv), ra);
        cpu_stq_data_ra(env, addr + 8, int128_getlo(newv), ra);
    }

    env->cc_op = fail;
    env->regs[r1] = int128_gethi(oldv);
    env->regs[r1 + 1] = int128_getlo(oldv);
}

#if !defined(CONFIG_USER_ONLY)
void HELPER(lctlg)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    S390CPU *cpu = s390_env_get_cpu(env);
    bool PERchanged = false;
    uint64_t src = a2;
    uint32_t i;

    for (i = r1;; i = (i + 1) % 16) {
        uint64_t val = cpu_ldq_data_ra(env, src, ra);
        if (env->cregs[i] != val && i >= 9 && i <= 11) {
            PERchanged = true;
        }
        env->cregs[i] = val;
        HELPER_LOG("load ctl %d from 0x%" PRIx64 " == 0x%" PRIx64 "\n",
                   i, src, val);
        src += sizeof(uint64_t);

        if (i == r3) {
            break;
        }
    }

    if (PERchanged && env->psw.mask & PSW_MASK_PER) {
        s390_cpu_recompute_watchpoints(CPU(cpu));
    }

    tlb_flush(CPU(cpu));
}

void HELPER(lctl)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    S390CPU *cpu = s390_env_get_cpu(env);
    bool PERchanged = false;
    uint64_t src = a2;
    uint32_t i;

    for (i = r1;; i = (i + 1) % 16) {
        uint32_t val = cpu_ldl_data_ra(env, src, ra);
        if ((uint32_t)env->cregs[i] != val && i >= 9 && i <= 11) {
            PERchanged = true;
        }
        env->cregs[i] = deposit64(env->cregs[i], 0, 32, val);
        HELPER_LOG("load ctl %d from 0x%" PRIx64 " == 0x%x\n", i, src, val);
        src += sizeof(uint32_t);

        if (i == r3) {
            break;
        }
    }

    if (PERchanged && env->psw.mask & PSW_MASK_PER) {
        s390_cpu_recompute_watchpoints(CPU(cpu));
    }

    tlb_flush(CPU(cpu));
}

void HELPER(stctg)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    uint64_t dest = a2;
    uint32_t i;

    for (i = r1;; i = (i + 1) % 16) {
        cpu_stq_data_ra(env, dest, env->cregs[i], ra);
        dest += sizeof(uint64_t);

        if (i == r3) {
            break;
        }
    }
}

void HELPER(stctl)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
{
    uintptr_t ra = GETPC();
    uint64_t dest = a2;
    uint32_t i;

    for (i = r1;; i = (i + 1) % 16) {
        cpu_stl_data_ra(env, dest, env->cregs[i], ra);
        dest += sizeof(uint32_t);

        if (i == r3) {
            break;
        }
    }
}

uint32_t HELPER(testblock)(CPUS390XState *env, uint64_t real_addr)
{
    uintptr_t ra = GETPC();
    CPUState *cs = CPU(s390_env_get_cpu(env));
    uint64_t abs_addr;
    int i;

    real_addr = fix_address(env, real_addr);
    abs_addr = mmu_real2abs(env, real_addr) & TARGET_PAGE_MASK;
    if (!address_space_access_valid(&address_space_memory, abs_addr,
                                    TARGET_PAGE_SIZE, true)) {
        cpu_restore_state(cs, ra);
        program_interrupt(env, PGM_ADDRESSING, 4);
        return 1;
    }

    /* Check low-address protection */
    if ((env->cregs[0] & CR0_LOWPROT) && real_addr < 0x2000) {
        cpu_restore_state(cs, ra);
        program_interrupt(env, PGM_PROTECTION, 4);
        return 1;
    }

    for (i = 0; i < TARGET_PAGE_SIZE; i += 8) {
        stq_phys(cs->as, abs_addr + i, 0);
    }

    return 0;
}

uint32_t HELPER(tprot)(uint64_t a1, uint64_t a2)
{
    /* XXX implement */
    return 0;
}

/* insert storage key extended */
uint64_t HELPER(iske)(CPUS390XState *env, uint64_t r2)
{
    static S390SKeysState *ss;
    static S390SKeysClass *skeyclass;
    uint64_t addr = get_address(env, 0, 0, r2);
    uint8_t key;

    if (addr > ram_size) {
        return 0;
    }

    if (unlikely(!ss)) {
        ss = s390_get_skeys_device();
        skeyclass = S390_SKEYS_GET_CLASS(ss);
    }

    if (skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key)) {
        return 0;
    }
    return key;
}

/* set storage key extended */
void HELPER(sske)(CPUS390XState *env, uint64_t r1, uint64_t r2)
{
    static S390SKeysState *ss;
    static S390SKeysClass *skeyclass;
    uint64_t addr = get_address(env, 0, 0, r2);
    uint8_t key;

    if (addr > ram_size) {
        return;
    }

    if (unlikely(!ss)) {
        ss = s390_get_skeys_device();
        skeyclass = S390_SKEYS_GET_CLASS(ss);
    }

    key = (uint8_t) r1;
    skeyclass->set_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
}

/* reset reference bit extended */
uint32_t HELPER(rrbe)(CPUS390XState *env, uint64_t r2)
{
    static S390SKeysState *ss;
    static S390SKeysClass *skeyclass;
    uint8_t re, key;

    if (r2 > ram_size) {
        return 0;
    }

    if (unlikely(!ss)) {
        ss = s390_get_skeys_device();
        skeyclass = S390_SKEYS_GET_CLASS(ss);
    }

    if (skeyclass->get_skeys(ss, r2 / TARGET_PAGE_SIZE, 1, &key)) {
        return 0;
    }

    re = key & (SK_R | SK_C);
    key &= ~SK_R;

    if (skeyclass->set_skeys(ss, r2 / TARGET_PAGE_SIZE, 1, &key)) {
        return 0;
    }

    /*
     * cc
     *
     * 0  Reference bit zero; change bit zero
     * 1  Reference bit zero; change bit one
     * 2  Reference bit one; change bit zero
     * 3  Reference bit one; change bit one
     */

    return re >> 1;
}

uint32_t HELPER(mvcs)(CPUS390XState *env, uint64_t l, uint64_t a1, uint64_t a2)
{
    uintptr_t ra = GETPC();
    int cc = 0, i;

    HELPER_LOG("%s: %16" PRIx64 " %16" PRIx64 " %16" PRIx64 "\n",
               __func__, l, a1, a2);

    if (l > 256) {
        /* max 256 */
        l = 256;
        cc = 3;
    }

    /* XXX replace w/ memcpy */
    for (i = 0; i < l; i++) {
        uint8_t x = cpu_ldub_primary_ra(env, a2 + i, ra);
        cpu_stb_secondary_ra(env, a1 + i, x, ra);
    }

    return cc;
}

uint32_t HELPER(mvcp)(CPUS390XState *env, uint64_t l, uint64_t a1, uint64_t a2)
{
    uintptr_t ra = GETPC();
    int cc = 0, i;

    HELPER_LOG("%s: %16" PRIx64 " %16" PRIx64 " %16" PRIx64 "\n",
               __func__, l, a1, a2);

    if (l > 256) {
        /* max 256 */
        l = 256;
        cc = 3;
    }

    /* XXX replace w/ memcpy */
    for (i = 0; i < l; i++) {
        uint8_t x = cpu_ldub_secondary_ra(env, a2 + i, ra);
        cpu_stb_primary_ra(env, a1 + i, x, ra);
    }

    return cc;
}

/* invalidate pte */
void HELPER(ipte)(CPUS390XState *env, uint64_t pto, uint64_t vaddr,
                  uint32_t m4)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));
    uint64_t page = vaddr & TARGET_PAGE_MASK;
    uint64_t pte_addr, pte;

    /* Compute the page table entry address */
    pte_addr = (pto & _SEGMENT_ENTRY_ORIGIN);
    pte_addr += (vaddr & VADDR_PX) >> 9;

    /* Mark the page table entry as invalid */
    pte = ldq_phys(cs->as, pte_addr);
    pte |= _PAGE_INVALID;
    stq_phys(cs->as, pte_addr, pte);

    /* XXX we exploit the fact that Linux passes the exact virtual
       address here - it's not obliged to! */
    /* XXX: the LC bit should be considered as 0 if the local-TLB-clearing
       facility is not installed.  */
    if (m4 & 1) {
        tlb_flush_page(cs, page);
    } else {
        tlb_flush_page_all_cpus_synced(cs, page);
    }

    /* XXX 31-bit hack */
    if (m4 & 1) {
        tlb_flush_page(cs, page ^ 0x80000000);
    } else {
        tlb_flush_page_all_cpus_synced(cs, page ^ 0x80000000);
    }
}

/* flush local tlb */
void HELPER(ptlb)(CPUS390XState *env)
{
    S390CPU *cpu = s390_env_get_cpu(env);

    tlb_flush(CPU(cpu));
}

/* flush global tlb */
void HELPER(purge)(CPUS390XState *env)
{
    S390CPU *cpu = s390_env_get_cpu(env);

    tlb_flush_all_cpus_synced(CPU(cpu));
}

/* load using real address */
uint64_t HELPER(lura)(CPUS390XState *env, uint64_t addr)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));

    return (uint32_t)ldl_phys(cs->as, get_address(env, 0, 0, addr));
}

uint64_t HELPER(lurag)(CPUS390XState *env, uint64_t addr)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));

    return ldq_phys(cs->as, get_address(env, 0, 0, addr));
}

/* store using real address */
void HELPER(stura)(CPUS390XState *env, uint64_t addr, uint64_t v1)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));

    stl_phys(cs->as, get_address(env, 0, 0, addr), (uint32_t)v1);

    if ((env->psw.mask & PSW_MASK_PER) &&
        (env->cregs[9] & PER_CR9_EVENT_STORE) &&
        (env->cregs[9] & PER_CR9_EVENT_STORE_REAL)) {
        /* PSW is saved just before calling the helper.  */
        env->per_address = env->psw.addr;
        env->per_perc_atmid = PER_CODE_EVENT_STORE_REAL | get_per_atmid(env);
    }
}

void HELPER(sturg)(CPUS390XState *env, uint64_t addr, uint64_t v1)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));

    stq_phys(cs->as, get_address(env, 0, 0, addr), v1);

    if ((env->psw.mask & PSW_MASK_PER) &&
        (env->cregs[9] & PER_CR9_EVENT_STORE) &&
        (env->cregs[9] & PER_CR9_EVENT_STORE_REAL)) {
        /* PSW is saved just before calling the helper.  */
        env->per_address = env->psw.addr;
        env->per_perc_atmid = PER_CODE_EVENT_STORE_REAL | get_per_atmid(env);
    }
}

/* load real address */
uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)
{
    CPUState *cs = CPU(s390_env_get_cpu(env));
    uint32_t cc = 0;
    uint64_t asc = env->psw.mask & PSW_MASK_ASC;
    uint64_t ret;
    int old_exc, flags;

    /* XXX incomplete - has more corner cases */
    if (!(env->psw.mask & PSW_MASK_64) && (addr >> 32)) {
        cpu_restore_state(cs, GETPC());
        program_interrupt(env, PGM_SPECIAL_OP, 2);
    }

    old_exc = cs->exception_index;
    if (mmu_translate(env, addr, 0, asc, &ret, &flags, true)) {
        cc = 3;
    }
    if (cs->exception_index == EXCP_PGM) {
        ret = env->int_pgm_code | 0x80000000;
    } else {
        ret |= addr & ~TARGET_PAGE_MASK;
    }
    cs->exception_index = old_exc;

    env->cc_op = cc;
    return ret;
}
#endif

/* Execute instruction.  This instruction executes an insn modified with
   the contents of r1.  It does not change the executed instruction in memory;
   it does not change the program counter.

   Perform this by recording the modified instruction in env->ex_value.
   This will be noticed by cpu_get_tb_cpu_state and thus tb translation.
*/
void HELPER(ex)(CPUS390XState *env, uint32_t ilen, uint64_t r1, uint64_t addr)
{
    uint64_t insn = cpu_lduw_code(env, addr);
    uint8_t opc = insn >> 8;

    /* Or in the contents of R1[56:63].  */
    insn |= r1 & 0xff;

    /* Load the rest of the instruction.  */
    insn <<= 48;
    switch (get_ilen(opc)) {
    case 2:
        break;
    case 4:
        insn |= (uint64_t)cpu_lduw_code(env, addr + 2) << 32;
        break;
    case 6:
        insn |= (uint64_t)(uint32_t)cpu_ldl_code(env, addr + 2) << 16;
        break;
    default:
        g_assert_not_reached();
    }

    /* The very most common cases can be sped up by avoiding a new TB.  */
    if ((opc & 0xf0) == 0xd0) {
        typedef uint32_t (*dx_helper)(CPUS390XState *, uint32_t, uint64_t,
                                      uint64_t, uintptr_t);
        static const dx_helper dx[16] = {
            [0x2] = do_helper_mvc,
            [0x4] = do_helper_nc,
            [0x5] = do_helper_clc,
            [0x6] = do_helper_oc,
            [0x7] = do_helper_xc,
            [0xc] = do_helper_tr,
            [0xd] = do_helper_trt,
        };
        dx_helper helper = dx[opc & 0xf];

        if (helper) {
            uint32_t l = extract64(insn, 48, 8);
            uint32_t b1 = extract64(insn, 44, 4);
            uint32_t d1 = extract64(insn, 32, 12);
            uint32_t b2 = extract64(insn, 28, 4);
            uint32_t d2 = extract64(insn, 16, 12);
            uint64_t a1 = get_address(env, 0, b1, d1);
            uint64_t a2 = get_address(env, 0, b2, d2);

            env->cc_op = helper(env, l, a1, a2, 0);
            env->psw.addr += ilen;
            return;
        }
    } else if (opc == 0x0a) {
        env->int_svc_code = extract64(insn, 48, 8);
        env->int_svc_ilen = ilen;
        helper_exception(env, EXCP_SVC);
        g_assert_not_reached();
    }

    /* Record the insn we want to execute as well as the ilen to use
       during the execution of the target insn.  This will also ensure
       that ex_value is non-zero, which flags that we are in a state
       that requires such execution.  */
    env->ex_value = insn | ilen;
}