target/riscv/op_helper.c

   1 /*
   2  * RISC-V Emulation Helpers for QEMU.
   3  *
   4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
   5  * Copyright (c) 2017-2018 SiFive, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2 or later, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "qemu/main-loop.h"
  23 #include "exec/exec-all.h"
  24 #include "exec/helper-proto.h"
  25
  26 /* Exceptions processing helpers */
  27 G_NORETURN void riscv_raise_exception(CPURISCVState *env,
  28                                       uint32_t exception, uintptr_t pc)
  29 {
  30     CPUState *cs = env_cpu(env);
  31     cs->exception_index = exception;
  32     cpu_loop_exit_restore(cs, pc);
  33 }
  34
  35 void helper_raise_exception(CPURISCVState *env, uint32_t exception)
  36 {
  37     riscv_raise_exception(env, exception, 0);
  38 }
  39
  40 target_ulong helper_csrr(CPURISCVState *env, int csr)
  41 {
  42     /*
  43      * The seed CSR must be accessed with a read-write instruction. A
  44      * read-only instruction such as CSRRS/CSRRC with rs1=x0 or CSRRSI/
  45      * CSRRCI with uimm=0 will raise an illegal instruction exception.
  46      */
  47     if (csr == CSR_SEED) {
  48         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  49     }
  50
  51     target_ulong val = 0;
  52     RISCVException ret = riscv_csrrw(env, csr, &val, 0, 0);
  53
  54     if (ret != RISCV_EXCP_NONE) {
  55         riscv_raise_exception(env, ret, GETPC());
  56     }
  57     return val;
  58 }
  59
  60 void helper_csrw(CPURISCVState *env, int csr, target_ulong src)
  61 {
  62     target_ulong mask = env->xl == MXL_RV32 ? UINT32_MAX : (target_ulong)-1;
  63     RISCVException ret = riscv_csrrw(env, csr, NULL, src, mask);
  64
  65     if (ret != RISCV_EXCP_NONE) {
  66         riscv_raise_exception(env, ret, GETPC());
  67     }
  68 }
  69
  70 target_ulong helper_csrrw(CPURISCVState *env, int csr,
  71                           target_ulong src, target_ulong write_mask)
  72 {
  73     target_ulong val = 0;
  74     RISCVException ret = riscv_csrrw(env, csr, &val, src, write_mask);
  75
  76     if (ret != RISCV_EXCP_NONE) {
  77         riscv_raise_exception(env, ret, GETPC());
  78     }
  79     return val;
  80 }
  81
  82 target_ulong helper_csrr_i128(CPURISCVState *env, int csr)
  83 {
  84     Int128 rv = int128_zero();
  85     RISCVException ret = riscv_csrrw_i128(env, csr, &rv,
  86                                           int128_zero(),
  87                                           int128_zero());
  88
  89     if (ret != RISCV_EXCP_NONE) {
  90         riscv_raise_exception(env, ret, GETPC());
  91     }
  92
  93     env->retxh = int128_gethi(rv);
  94     return int128_getlo(rv);
  95 }
  96
  97 void helper_csrw_i128(CPURISCVState *env, int csr,
  98                       target_ulong srcl, target_ulong srch)
  99 {
 100     RISCVException ret = riscv_csrrw_i128(env, csr, NULL,
 101                                           int128_make128(srcl, srch),
 102                                           UINT128_MAX);
 103
 104     if (ret != RISCV_EXCP_NONE) {
 105         riscv_raise_exception(env, ret, GETPC());
 106     }
 107 }
 108
 109 target_ulong helper_csrrw_i128(CPURISCVState *env, int csr,
 110                        target_ulong srcl, target_ulong srch,
 111                        target_ulong maskl, target_ulong maskh)
 112 {
 113     Int128 rv = int128_zero();
 114     RISCVException ret = riscv_csrrw_i128(env, csr, &rv,
 115                                           int128_make128(srcl, srch),
 116                                           int128_make128(maskl, maskh));
 117
 118     if (ret != RISCV_EXCP_NONE) {
 119         riscv_raise_exception(env, ret, GETPC());
 120     }
 121
 122     env->retxh = int128_gethi(rv);
 123     return int128_getlo(rv);
 124 }
 125
 126 #ifndef CONFIG_USER_ONLY
 127
 128 target_ulong helper_sret(CPURISCVState *env)
 129 {
 130     uint64_t mstatus;
 131     target_ulong prev_priv, prev_virt;
 132
 133     if (!(env->priv >= PRV_S)) {
 134         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 135     }
 136
 137     target_ulong retpc = env->sepc;
 138     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
 139         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
 140     }
 141
 142     if (get_field(env->mstatus, MSTATUS_TSR) && !(env->priv >= PRV_M)) {
 143         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 144     }
 145
 146     if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
 147         get_field(env->hstatus, HSTATUS_VTSR)) {
 148         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
 149     }
 150
 151     mstatus = env->mstatus;
 152
 153     if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
 154         /* We support Hypervisor extensions and virtulisation is disabled */
 155         target_ulong hstatus = env->hstatus;
 156
 157         prev_priv = get_field(mstatus, MSTATUS_SPP);
 158         prev_virt = get_field(hstatus, HSTATUS_SPV);
 159
 160         hstatus = set_field(hstatus, HSTATUS_SPV, 0);
 161         mstatus = set_field(mstatus, MSTATUS_SPP, 0);
 162         mstatus = set_field(mstatus, SSTATUS_SIE,
 163                             get_field(mstatus, SSTATUS_SPIE));
 164         mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
 165
 166         env->mstatus = mstatus;
 167         env->hstatus = hstatus;
 168
 169         if (prev_virt) {
 170             riscv_cpu_swap_hypervisor_regs(env);
 171         }
 172
 173         riscv_cpu_set_virt_enabled(env, prev_virt);
 174     } else {
 175         prev_priv = get_field(mstatus, MSTATUS_SPP);
 176
 177         mstatus = set_field(mstatus, MSTATUS_SIE,
 178                             get_field(mstatus, MSTATUS_SPIE));
 179         mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
 180         mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
 181         env->mstatus = mstatus;
 182     }
 183
 184     riscv_cpu_set_mode(env, prev_priv);
 185
 186     return retpc;
 187 }
 188
 189 target_ulong helper_mret(CPURISCVState *env)
 190 {
 191     if (!(env->priv >= PRV_M)) {
 192         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 193     }
 194
 195     target_ulong retpc = env->mepc;
 196     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
 197         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
 198     }
 199
 200     uint64_t mstatus = env->mstatus;
 201     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
 202
 203     if (riscv_feature(env, RISCV_FEATURE_PMP) &&
 204         !pmp_get_num_rules(env) && (prev_priv != PRV_M)) {
 205         riscv_raise_exception(env, RISCV_EXCP_INST_ACCESS_FAULT, GETPC());
 206     }
 207
 208     target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV);
 209     mstatus = set_field(mstatus, MSTATUS_MIE,
 210                         get_field(mstatus, MSTATUS_MPIE));
 211     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
 212     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
 213     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
 214     env->mstatus = mstatus;
 215     riscv_cpu_set_mode(env, prev_priv);
 216
 217     if (riscv_has_ext(env, RVH)) {
 218         if (prev_virt) {
 219             riscv_cpu_swap_hypervisor_regs(env);
 220         }
 221
 222         riscv_cpu_set_virt_enabled(env, prev_virt);
 223     }
 224
 225     return retpc;
 226 }
 227
 228 void helper_wfi(CPURISCVState *env)
 229 {
 230     CPUState *cs = env_cpu(env);
 231     bool rvs = riscv_has_ext(env, RVS);
 232     bool prv_u = env->priv == PRV_U;
 233     bool prv_s = env->priv == PRV_S;
 234
 235     if (((prv_s || (!rvs && prv_u)) && get_field(env->mstatus, MSTATUS_TW)) ||
 236         (rvs && prv_u && !riscv_cpu_virt_enabled(env))) {
 237         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 238     } else if (riscv_cpu_virt_enabled(env) && (prv_u ||
 239         (prv_s && get_field(env->hstatus, HSTATUS_VTW)))) {
 240         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
 241     } else {
 242         cs->halted = 1;
 243         cs->exception_index = EXCP_HLT;
 244         cpu_loop_exit(cs);
 245     }
 246 }
 247
 248 void helper_tlb_flush(CPURISCVState *env)
 249 {
 250     CPUState *cs = env_cpu(env);
 251     if (!(env->priv >= PRV_S) ||
 252         (env->priv == PRV_S &&
 253          get_field(env->mstatus, MSTATUS_TVM))) {
 254         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 255     } else if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
 256                get_field(env->hstatus, HSTATUS_VTVM)) {
 257         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
 258     } else {
 259         tlb_flush(cs);
 260     }
 261 }
 262
 263 void helper_hyp_tlb_flush(CPURISCVState *env)
 264 {
 265     CPUState *cs = env_cpu(env);
 266
 267     if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
 268         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
 269     }
 270
 271     if (env->priv == PRV_M ||
 272         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
 273         tlb_flush(cs);
 274         return;
 275     }
 276
 277     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 278 }
 279
 280 void helper_hyp_gvma_tlb_flush(CPURISCVState *env)
 281 {
 282     if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env) &&
 283         get_field(env->mstatus, MSTATUS_TVM)) {
 284         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 285     }
 286
 287     helper_hyp_tlb_flush(env);
 288 }
 289
 290 target_ulong helper_hyp_hlvx_hu(CPURISCVState *env, target_ulong address)
 291 {
 292     int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
 293
 294     return cpu_lduw_mmuidx_ra(env, address, mmu_idx, GETPC());
 295 }
 296
 297 target_ulong helper_hyp_hlvx_wu(CPURISCVState *env, target_ulong address)
 298 {
 299     int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
 300
 301     return cpu_ldl_mmuidx_ra(env, address, mmu_idx, GETPC());
 302 }
 303
 304 #endif /* !CONFIG_USER_ONLY */