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 if (!(env->priv >= PRV_S)) { 77 riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); 78 } 79 80 target_ulong retpc = env->sepc; 81 if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) { 82 riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC()); 83 } 84 85 if (env->priv_ver >= PRIV_VERSION_1_10_0 && 86 get_field(env->mstatus, MSTATUS_TSR)) { 87 riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); 88 } 89 90 target_ulong mstatus = env->mstatus; 91 target_ulong prev_priv = get_field(mstatus, MSTATUS_SPP); 92 mstatus = set_field(mstatus, 93 env->priv_ver >= PRIV_VERSION_1_10_0 ? 94 MSTATUS_SIE : MSTATUS_UIE << prev_priv, 95 get_field(mstatus, MSTATUS_SPIE)); 96 mstatus = set_field(mstatus, MSTATUS_SPIE, 0); 97 mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U); 98 riscv_cpu_set_mode(env, prev_priv); 99 env->mstatus = mstatus; 100 101 return retpc; 102 } 103 104 target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb) 105 { 106 if (!(env->priv >= PRV_M)) { 107 riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); 108 } 109 110 target_ulong retpc = env->mepc; 111 if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) { 112 riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC()); 113 } 114 115 target_ulong mstatus = env->mstatus; 116 target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP); 117 mstatus = set_field(mstatus, 118 env->priv_ver >= PRIV_VERSION_1_10_0 ? 119 MSTATUS_MIE : MSTATUS_UIE << prev_priv, 120 get_field(mstatus, MSTATUS_MPIE)); 121 mstatus = set_field(mstatus, MSTATUS_MPIE, 0); 122 mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U); 123 riscv_cpu_set_mode(env, prev_priv); 124 env->mstatus = mstatus; 125 126 return retpc; 127 } 128 129 void helper_wfi(CPURISCVState *env) 130 { 131 CPUState *cs = env_cpu(env); 132 133 if (env->priv == PRV_S && 134 env->priv_ver >= PRIV_VERSION_1_10_0 && 135 get_field(env->mstatus, MSTATUS_TW)) { 136 riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); 137 } else { 138 cs->halted = 1; 139 cs->exception_index = EXCP_HLT; 140 cpu_loop_exit(cs); 141 } 142 } 143 144 void helper_tlb_flush(CPURISCVState *env) 145 { 146 CPUState *cs = env_cpu(env); 147 if (!(env->priv >= PRV_S) || 148 (env->priv == PRV_S && 149 env->priv_ver >= PRIV_VERSION_1_10_0 && 150 get_field(env->mstatus, MSTATUS_TVM))) { 151 riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); 152 } else { 153 tlb_flush(cs); 154 } 155 } 156 157 #endif /* !CONFIG_USER_ONLY */ 158