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     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 */