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 "qemu/log.h"
  22 #include "cpu.h"
  23 #include "qemu/main-loop.h"
  24 #include "exec/exec-all.h"
  25 #include "exec/helper-proto.h"
  26
  27 /* Exceptions processing helpers */
  28 void QEMU_NORETURN riscv_raise_exception(CPURISCVState *env,
  29                                           uint32_t exception, uintptr_t pc)
  30 {
  31     CPUState *cs = env_cpu(env);
  32     qemu_log_mask(CPU_LOG_INT, "%s: %d\n", __func__, exception);
  33     cs->exception_index = exception;
  34     cpu_loop_exit_restore(cs, pc);
  35 }
  36
  37 void helper_raise_exception(CPURISCVState *env, uint32_t exception)
  38 {
  39     riscv_raise_exception(env, exception, 0);
  40 }
  41
  42 target_ulong helper_csrrw(CPURISCVState *env, target_ulong src,
  43         target_ulong csr)
  44 {
  45     target_ulong val = 0;
  46     if (riscv_csrrw(env, csr, &val, src, -1) < 0) {
  47         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  48     }
  49     return val;
  50 }
  51
  52 target_ulong helper_csrrs(CPURISCVState *env, target_ulong src,
  53         target_ulong csr, target_ulong rs1_pass)
  54 {
  55     target_ulong val = 0;
  56     if (riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0) < 0) {
  57         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  58     }
  59     return val;
  60 }
  61
  62 target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
  63         target_ulong csr, target_ulong rs1_pass)
  64 {
  65     target_ulong val = 0;
  66     if (riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0) < 0) {
  67         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  68     }
  69     return val;
  70 }
  71
  72 #ifndef CONFIG_USER_ONLY
  73
  74 target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
  75 {
  76     target_ulong prev_priv, prev_virt, mstatus;
  77
  78     if (!(env->priv >= PRV_S)) {
  79         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  80     }
  81
  82     target_ulong retpc = env->sepc;
  83     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
  84         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
  85     }
  86
  87     if (get_field(env->mstatus, MSTATUS_TSR) && !(env->priv >= PRV_M)) {
  88         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
  89     }
  90
  91     mstatus = env->mstatus;
  92
  93     if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
  94         /* We support Hypervisor extensions and virtulisation is disabled */
  95         target_ulong hstatus = env->hstatus;
  96
  97         prev_priv = get_field(mstatus, MSTATUS_SPP);
  98         prev_virt = get_field(hstatus, HSTATUS_SPV);
  99
 100         hstatus = set_field(hstatus, HSTATUS_SPV,
 101                                  get_field(hstatus, HSTATUS_SP2V));
 102         mstatus = set_field(mstatus, MSTATUS_SPP,
 103                             get_field(hstatus, HSTATUS_SP2P));
 104         hstatus = set_field(hstatus, HSTATUS_SP2V, 0);
 105         hstatus = set_field(hstatus, HSTATUS_SP2P, 0);
 106         mstatus = set_field(mstatus, SSTATUS_SIE,
 107                             get_field(mstatus, SSTATUS_SPIE));
 108         mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
 109
 110         env->mstatus = mstatus;
 111         env->hstatus = hstatus;
 112
 113         if (prev_virt) {
 114             riscv_cpu_swap_hypervisor_regs(env);
 115         }
 116
 117         riscv_cpu_set_virt_enabled(env, prev_virt);
 118     } else {
 119         prev_priv = get_field(mstatus, MSTATUS_SPP);
 120
 121         mstatus = set_field(mstatus, MSTATUS_SIE,
 122                             get_field(mstatus, MSTATUS_SPIE));
 123         mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
 124         mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
 125         env->mstatus = mstatus;
 126     }
 127
 128     riscv_cpu_set_mode(env, prev_priv);
 129
 130     return retpc;
 131 }
 132
 133 target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
 134 {
 135     if (!(env->priv >= PRV_M)) {
 136         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 137     }
 138
 139     target_ulong retpc = env->mepc;
 140     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
 141         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
 142     }
 143
 144     target_ulong mstatus = env->mstatus;
 145     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
 146     target_ulong prev_virt = MSTATUS_MPV_ISSET(env);
 147     mstatus = set_field(mstatus, MSTATUS_MIE,
 148                         get_field(mstatus, MSTATUS_MPIE));
 149     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
 150     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
 151 #ifdef TARGET_RISCV32
 152     env->mstatush = set_field(env->mstatush, MSTATUS_MPV, 0);
 153 #else
 154     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
 155 #endif
 156     env->mstatus = mstatus;
 157     riscv_cpu_set_mode(env, prev_priv);
 158
 159     if (riscv_has_ext(env, RVH)) {
 160         if (prev_virt) {
 161             riscv_cpu_swap_hypervisor_regs(env);
 162         }
 163
 164         riscv_cpu_set_virt_enabled(env, prev_virt);
 165     }
 166
 167     return retpc;
 168 }
 169
 170 void helper_wfi(CPURISCVState *env)
 171 {
 172     CPUState *cs = env_cpu(env);
 173
 174     if ((env->priv == PRV_S &&
 175         get_field(env->mstatus, MSTATUS_TW)) ||
 176         riscv_cpu_virt_enabled(env)) {
 177         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 178     } else {
 179         cs->halted = 1;
 180         cs->exception_index = EXCP_HLT;
 181         cpu_loop_exit(cs);
 182     }
 183 }
 184
 185 void helper_tlb_flush(CPURISCVState *env)
 186 {
 187     CPUState *cs = env_cpu(env);
 188     if (!(env->priv >= PRV_S) ||
 189         (env->priv == PRV_S &&
 190          get_field(env->mstatus, MSTATUS_TVM))) {
 191         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 192     } else {
 193         tlb_flush(cs);
 194     }
 195 }
 196
 197 void helper_hyp_tlb_flush(CPURISCVState *env)
 198 {
 199     CPUState *cs = env_cpu(env);
 200
 201     if (env->priv == PRV_M ||
 202         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
 203         tlb_flush(cs);
 204         return;
 205     }
 206
 207     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
 208 }
 209
 210 #endif /* !CONFIG_USER_ONLY */