Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 462 insertions, 0 deletions

diff --git a/target/rx/op_helper.c b/target/rx/op_helper.c
new file mode 100644
index 000000000..11f952d34
--- /dev/null
+++ b/target/rx/op_helper.c
@@ -0,0 +1,462 @@
+/*
+ *  RX helper functions
+ *
+ *  Copyright (c) 2019 Yoshinori Sato
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/bitops.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include "exec/cpu_ldst.h"
+#include "fpu/softfloat.h"
+
+static inline void QEMU_NORETURN raise_exception(CPURXState *env, int index,
+                                                 uintptr_t retaddr);
+
+static void _set_psw(CPURXState *env, uint32_t psw, uint32_t rte)
+{
+    uint32_t prev_u;
+    prev_u = env->psw_u;
+    rx_cpu_unpack_psw(env, psw, rte);
+    if (prev_u != env->psw_u) {
+        /* switch r0  */
+        if (env->psw_u) {
+            env->isp = env->regs[0];
+            env->regs[0] = env->usp;
+        } else {
+            env->usp = env->regs[0];
+            env->regs[0] = env->isp;
+        }
+    }
+}
+
+void helper_set_psw(CPURXState *env, uint32_t psw)
+{
+    _set_psw(env, psw, 0);
+}
+
+void helper_set_psw_rte(CPURXState *env, uint32_t psw)
+{
+    _set_psw(env, psw, 1);
+}
+
+uint32_t helper_pack_psw(CPURXState *env)
+{
+    return rx_cpu_pack_psw(env);
+}
+
+#define SET_FPSW(b)                                             \
+    do {                                                        \
+        env->fpsw = FIELD_DP32(env->fpsw, FPSW, C ## b, 1);     \
+        if (!FIELD_EX32(env->fpsw, FPSW, E ## b)) {             \
+            env->fpsw = FIELD_DP32(env->fpsw, FPSW, F ## b, 1); \
+        }                                                       \
+    } while (0)
+
+/* fp operations */
+static void update_fpsw(CPURXState *env, float32 ret, uintptr_t retaddr)
+{
+    int xcpt, cause, enable;
+
+    env->psw_z = ret & ~(1 << 31); /* mask sign bit */
+    env->psw_s = ret;
+
+    xcpt = get_float_exception_flags(&env->fp_status);
+
+    /* Clear the cause entries */
+    env->fpsw = FIELD_DP32(env->fpsw, FPSW, CAUSE, 0);
+
+    /* set FPSW */
+    if (unlikely(xcpt)) {
+        if (xcpt & float_flag_invalid) {
+            SET_FPSW(V);
+        }
+        if (xcpt & float_flag_divbyzero) {
+            SET_FPSW(Z);
+        }
+        if (xcpt & float_flag_overflow) {
+            SET_FPSW(O);
+        }
+        if (xcpt & float_flag_underflow) {
+            SET_FPSW(U);
+        }
+        if (xcpt & float_flag_inexact) {
+            SET_FPSW(X);
+        }
+        if ((xcpt & (float_flag_input_denormal
+                     | float_flag_output_denormal))
+            && !FIELD_EX32(env->fpsw, FPSW, DN)) {
+            env->fpsw = FIELD_DP32(env->fpsw, FPSW, CE, 1);
+        }
+
+        /* update FPSW_FLAG_S */
+        if (FIELD_EX32(env->fpsw, FPSW, FLAGS) != 0) {
+            env->fpsw = FIELD_DP32(env->fpsw, FPSW, FS, 1);
+        }
+
+        /* Generate an exception if enabled */
+        cause = FIELD_EX32(env->fpsw, FPSW, CAUSE);
+        enable = FIELD_EX32(env->fpsw, FPSW, ENABLE);
+        enable |= 1 << 5; /* CE always enabled */
+        if (cause & enable) {
+            raise_exception(env, 21, retaddr);
+        }
+    }
+}
+
+void helper_set_fpsw(CPURXState *env, uint32_t val)
+{
+    static const int roundmode[] = {
+        float_round_nearest_even,
+        float_round_to_zero,
+        float_round_up,
+        float_round_down,
+    };
+    uint32_t fpsw = env->fpsw;
+    fpsw |= 0x7fffff03;
+    val &= ~0x80000000;
+    fpsw &= val;
+    FIELD_DP32(fpsw, FPSW, FS, FIELD_EX32(fpsw, FPSW, FLAGS) != 0);
+    env->fpsw = fpsw;
+    set_float_rounding_mode(roundmode[FIELD_EX32(env->fpsw, FPSW, RM)],
+                            &env->fp_status);
+}
+
+#define FLOATOP(op, func)                                           \
+    float32 helper_##op(CPURXState *env, float32 t0, float32 t1)    \
+    {                                                               \
+        float32 ret;                                                \
+        ret = func(t0, t1, &env->fp_status);                        \
+        update_fpsw(env, *(uint32_t *)&ret, GETPC());               \
+        return ret;                                                 \
+    }
+
+FLOATOP(fadd, float32_add)
+FLOATOP(fsub, float32_sub)
+FLOATOP(fmul, float32_mul)
+FLOATOP(fdiv, float32_div)
+
+void helper_fcmp(CPURXState *env, float32 t0, float32 t1)
+{
+    int st;
+    st = float32_compare(t0, t1, &env->fp_status);
+    update_fpsw(env, 0, GETPC());
+    env->psw_z = 1;
+    env->psw_s = env->psw_o = 0;
+    switch (st) {
+    case float_relation_equal:
+        env->psw_z = 0;
+        break;
+    case float_relation_less:
+        env->psw_s = -1;
+        break;
+    case float_relation_unordered:
+        env->psw_o = -1;
+        break;
+    }
+}
+
+uint32_t helper_ftoi(CPURXState *env, float32 t0)
+{
+    uint32_t ret;
+    ret = float32_to_int32_round_to_zero(t0, &env->fp_status);
+    update_fpsw(env, ret, GETPC());
+    return ret;
+}
+
+uint32_t helper_round(CPURXState *env, float32 t0)
+{
+    uint32_t ret;
+    ret = float32_to_int32(t0, &env->fp_status);
+    update_fpsw(env, ret, GETPC());
+    return ret;
+}
+
+float32 helper_itof(CPURXState *env, uint32_t t0)
+{
+    float32 ret;
+    ret = int32_to_float32(t0, &env->fp_status);
+    update_fpsw(env, ret, GETPC());
+    return ret;
+}
+
+/* string operations */
+void helper_scmpu(CPURXState *env)
+{
+    uint8_t tmp0, tmp1;
+    if (env->regs[3] == 0) {
+        return;
+    }
+    do {
+        tmp0 = cpu_ldub_data_ra(env, env->regs[1]++, GETPC());
+        tmp1 = cpu_ldub_data_ra(env, env->regs[2]++, GETPC());
+        env->regs[3]--;
+        if (tmp0 != tmp1 || tmp0 == '\0') {
+            break;
+        }
+    } while (env->regs[3] != 0);
+    env->psw_z = tmp0 - tmp1;
+    env->psw_c = (tmp0 >= tmp1);
+}
+
+static uint32_t (* const cpu_ldufn[])(CPUArchState *env,
+                                     target_ulong ptr,
+                                     uintptr_t retaddr) = {
+    cpu_ldub_data_ra, cpu_lduw_data_ra, cpu_ldl_data_ra,
+};
+
+static uint32_t (* const cpu_ldfn[])(CPUArchState *env,
+                                     target_ulong ptr,
+                                     uintptr_t retaddr) = {
+    cpu_ldub_data_ra, cpu_lduw_data_ra, cpu_ldl_data_ra,
+};
+
+static void (* const cpu_stfn[])(CPUArchState *env,
+                                 target_ulong ptr,
+                                 uint32_t val,
+                                 uintptr_t retaddr) = {
+    cpu_stb_data_ra, cpu_stw_data_ra, cpu_stl_data_ra,
+};
+
+void helper_sstr(CPURXState *env, uint32_t sz)
+{
+    tcg_debug_assert(sz < 3);
+    while (env->regs[3] != 0) {
+        cpu_stfn[sz](env, env->regs[1], env->regs[2], GETPC());
+        env->regs[1] += 1 << sz;
+        env->regs[3]--;
+    }
+}
+
+#define OP_SMOVU 1
+#define OP_SMOVF 0
+#define OP_SMOVB 2
+
+static void smov(uint32_t mode, CPURXState *env)
+{
+    uint8_t tmp;
+    int dir;
+
+    dir = (mode & OP_SMOVB) ? -1 : 1;
+    while (env->regs[3] != 0) {
+        tmp = cpu_ldub_data_ra(env, env->regs[2], GETPC());
+        cpu_stb_data_ra(env, env->regs[1], tmp, GETPC());
+        env->regs[1] += dir;
+        env->regs[2] += dir;
+        env->regs[3]--;
+        if ((mode & OP_SMOVU) && tmp == 0) {
+            break;
+        }
+    }
+}
+
+void helper_smovu(CPURXState *env)
+{
+    smov(OP_SMOVU, env);
+}
+
+void helper_smovf(CPURXState *env)
+{
+    smov(OP_SMOVF, env);
+}
+
+void helper_smovb(CPURXState *env)
+{
+    smov(OP_SMOVB, env);
+}
+
+
+void helper_suntil(CPURXState *env, uint32_t sz)
+{
+    uint32_t tmp;
+    tcg_debug_assert(sz < 3);
+    if (env->regs[3] == 0) {
+        return ;
+    }
+    do {
+        tmp = cpu_ldufn[sz](env, env->regs[1], GETPC());
+        env->regs[1] += 1 << sz;
+        env->regs[3]--;
+        if (tmp == env->regs[2]) {
+            break;
+        }
+    } while (env->regs[3] != 0);
+    env->psw_z = tmp - env->regs[2];
+    env->psw_c = (tmp <= env->regs[2]);
+}
+
+void helper_swhile(CPURXState *env, uint32_t sz)
+{
+    uint32_t tmp;
+    tcg_debug_assert(sz < 3);
+    if (env->regs[3] == 0) {
+        return ;
+    }
+    do {
+        tmp = cpu_ldufn[sz](env, env->regs[1], GETPC());
+        env->regs[1] += 1 << sz;
+        env->regs[3]--;
+        if (tmp != env->regs[2]) {
+            break;
+        }
+    } while (env->regs[3] != 0);
+    env->psw_z = env->regs[3];
+    env->psw_c = (tmp <= env->regs[2]);
+}
+
+/* accumulator operations */
+void helper_rmpa(CPURXState *env, uint32_t sz)
+{
+    uint64_t result_l, prev;
+    int32_t result_h;
+    int64_t tmp0, tmp1;
+
+    if (env->regs[3] == 0) {
+        return;
+    }
+    result_l = env->regs[5];
+    result_l <<= 32;
+    result_l |= env->regs[4];
+    result_h = env->regs[6];
+    env->psw_o = 0;
+
+    while (env->regs[3] != 0) {
+        tmp0 = cpu_ldfn[sz](env, env->regs[1], GETPC());
+        tmp1 = cpu_ldfn[sz](env, env->regs[2], GETPC());
+        tmp0 *= tmp1;
+        prev = result_l;
+        result_l += tmp0;
+        /* carry / bollow */
+        if (tmp0 < 0) {
+            if (prev > result_l) {
+                result_h--;
+            }
+        } else {
+            if (prev < result_l) {
+                result_h++;
+            }
+        }
+
+        env->regs[1] += 1 << sz;
+        env->regs[2] += 1 << sz;
+    }
+    env->psw_s = result_h;
+    env->psw_o = (result_h != 0 && result_h != -1) << 31;
+    env->regs[6] = result_h;
+    env->regs[5] = result_l >> 32;
+    env->regs[4] = result_l & 0xffffffff;
+}
+
+void helper_racw(CPURXState *env, uint32_t imm)
+{
+    int64_t acc;
+    acc = env->acc;
+    acc <<= (imm + 1);
+    acc += 0x0000000080000000LL;
+    if (acc > 0x00007fff00000000LL) {
+        acc = 0x00007fff00000000LL;
+    } else if (acc < -0x800000000000LL) {
+        acc = -0x800000000000LL;
+    } else {
+        acc &= 0xffffffff00000000LL;
+    }
+    env->acc = acc;
+}
+
+void helper_satr(CPURXState *env)
+{
+    if (env->psw_o >> 31) {
+        if ((int)env->psw_s < 0) {
+            env->regs[6] = 0x00000000;
+            env->regs[5] = 0x7fffffff;
+            env->regs[4] = 0xffffffff;
+        } else {
+            env->regs[6] = 0xffffffff;
+            env->regs[5] = 0x80000000;
+            env->regs[4] = 0x00000000;
+        }
+    }
+}
+
+/* div */
+uint32_t helper_div(CPURXState *env, uint32_t num, uint32_t den)
+{
+    uint32_t ret = num;
+    if (!((num == INT_MIN && den == -1) || den == 0)) {
+        ret = (int32_t)num / (int32_t)den;
+        env->psw_o = 0;
+    } else {
+        env->psw_o = -1;
+    }
+    return ret;
+}
+
+uint32_t helper_divu(CPURXState *env, uint32_t num, uint32_t den)
+{
+    uint32_t ret = num;
+    if (den != 0) {
+        ret = num / den;
+        env->psw_o = 0;
+    } else {
+        env->psw_o = -1;
+    }
+    return ret;
+}
+
+/* exception */
+static inline void QEMU_NORETURN raise_exception(CPURXState *env, int index,
+                                                 uintptr_t retaddr)
+{
+    CPUState *cs = env_cpu(env);
+
+    cs->exception_index = index;
+    cpu_loop_exit_restore(cs, retaddr);
+}
+
+void QEMU_NORETURN helper_raise_privilege_violation(CPURXState *env)
+{
+    raise_exception(env, 20, GETPC());
+}
+
+void QEMU_NORETURN helper_raise_access_fault(CPURXState *env)
+{
+    raise_exception(env, 21, GETPC());
+}
+
+void QEMU_NORETURN helper_raise_illegal_instruction(CPURXState *env)
+{
+    raise_exception(env, 23, GETPC());
+}
+
+void QEMU_NORETURN helper_wait(CPURXState *env)
+{
+    CPUState *cs = env_cpu(env);
+
+    cs->halted = 1;
+    env->in_sleep = 1;
+    raise_exception(env, EXCP_HLT, 0);
+}
+
+void QEMU_NORETURN helper_rxint(CPURXState *env, uint32_t vec)
+{
+    raise_exception(env, 0x100 + vec, 0);
+}
+
+void QEMU_NORETURN helper_rxbrk(CPURXState *env)
+{
+    raise_exception(env, 0x100, 0);
+}