xref: /qemu/target/riscv/op_helper.c (revision 92eecfff) 
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     cs->exception_index = exception;
33     cpu_loop_exit_restore(cs, pc);
34 }
35 
36 void helper_raise_exception(CPURISCVState *env, uint32_t exception)
37 {
38     riscv_raise_exception(env, exception, 0);
39 }
40 
41 target_ulong helper_csrrw(CPURISCVState *env, target_ulong src,
42         target_ulong csr)
43 {
44     target_ulong val = 0;
45     int ret = riscv_csrrw(env, csr, &val, src, -1);
46 
47     if (ret < 0) {
48         riscv_raise_exception(env, -ret, GETPC());
49     }
50     return val;
51 }
52 
53 target_ulong helper_csrrs(CPURISCVState *env, target_ulong src,
54         target_ulong csr, target_ulong rs1_pass)
55 {
56     target_ulong val = 0;
57     int ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
58 
59     if (ret < 0) {
60         riscv_raise_exception(env, -ret, GETPC());
61     }
62     return val;
63 }
64 
65 target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
66         target_ulong csr, target_ulong rs1_pass)
67 {
68     target_ulong val = 0;
69     int ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
70 
71     if (ret < 0) {
72         riscv_raise_exception(env, -ret, GETPC());
73     }
74     return val;
75 }
76 
77 #ifndef CONFIG_USER_ONLY
78 
79 target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
80 {
81     uint64_t mstatus;
82     target_ulong prev_priv, prev_virt;
83 
84     if (!(env->priv >= PRV_S)) {
85         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
86     }
87 
88     target_ulong retpc = env->sepc;
89     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
90         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
91     }
92 
93     if (get_field(env->mstatus, MSTATUS_TSR) && !(env->priv >= PRV_M)) {
94         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
95     }
96 
97     if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
98         get_field(env->hstatus, HSTATUS_VTSR)) {
99         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
100     }
101 
102     mstatus = env->mstatus;
103 
104     if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
105         /* We support Hypervisor extensions and virtulisation is disabled */
106         target_ulong hstatus = env->hstatus;
107 
108         prev_priv = get_field(mstatus, MSTATUS_SPP);
109         prev_virt = get_field(hstatus, HSTATUS_SPV);
110 
111         hstatus = set_field(hstatus, HSTATUS_SPV, 0);
112         mstatus = set_field(mstatus, MSTATUS_SPP, 0);
113         mstatus = set_field(mstatus, SSTATUS_SIE,
114                             get_field(mstatus, SSTATUS_SPIE));
115         mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
116 
117         env->mstatus = mstatus;
118         env->hstatus = hstatus;
119 
120         if (prev_virt) {
121             riscv_cpu_swap_hypervisor_regs(env);
122         }
123 
124         riscv_cpu_set_virt_enabled(env, prev_virt);
125     } else {
126         prev_priv = get_field(mstatus, MSTATUS_SPP);
127 
128         mstatus = set_field(mstatus, MSTATUS_SIE,
129                             get_field(mstatus, MSTATUS_SPIE));
130         mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
131         mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
132         env->mstatus = mstatus;
133     }
134 
135     riscv_cpu_set_mode(env, prev_priv);
136 
137     return retpc;
138 }
139 
140 target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
141 {
142     if (!(env->priv >= PRV_M)) {
143         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
144     }
145 
146     target_ulong retpc = env->mepc;
147     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
148         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
149     }
150 
151     uint64_t mstatus = env->mstatus;
152     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
153     target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV);
154     mstatus = set_field(mstatus, MSTATUS_MIE,
155                         get_field(mstatus, MSTATUS_MPIE));
156     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
157     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
158     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
159     env->mstatus = mstatus;
160     riscv_cpu_set_mode(env, prev_priv);
161 
162     if (riscv_has_ext(env, RVH)) {
163         if (prev_virt) {
164             riscv_cpu_swap_hypervisor_regs(env);
165         }
166 
167         riscv_cpu_set_virt_enabled(env, prev_virt);
168     }
169 
170     return retpc;
171 }
172 
173 void helper_wfi(CPURISCVState *env)
174 {
175     CPUState *cs = env_cpu(env);
176 
177     if ((env->priv == PRV_S &&
178         get_field(env->mstatus, MSTATUS_TW)) ||
179         riscv_cpu_virt_enabled(env)) {
180         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
181     } else {
182         cs->halted = 1;
183         cs->exception_index = EXCP_HLT;
184         cpu_loop_exit(cs);
185     }
186 }
187 
188 void helper_tlb_flush(CPURISCVState *env)
189 {
190     CPUState *cs = env_cpu(env);
191     if (!(env->priv >= PRV_S) ||
192         (env->priv == PRV_S &&
193          get_field(env->mstatus, MSTATUS_TVM))) {
194         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
195     } else if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
196                get_field(env->hstatus, HSTATUS_VTVM)) {
197         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
198     } else {
199         tlb_flush(cs);
200     }
201 }
202 
203 void helper_hyp_tlb_flush(CPURISCVState *env)
204 {
205     CPUState *cs = env_cpu(env);
206 
207     if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
208         riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
209     }
210 
211     if (env->priv == PRV_M ||
212         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
213         tlb_flush(cs);
214         return;
215     }
216 
217     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
218 }
219 
220 void helper_hyp_gvma_tlb_flush(CPURISCVState *env)
221 {
222     if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env) &&
223         get_field(env->mstatus, MSTATUS_TVM)) {
224         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
225     }
226 
227     helper_hyp_tlb_flush(env);
228 }
229 
230 target_ulong helper_hyp_hlvx_hu(CPURISCVState *env, target_ulong address)
231 {
232     int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
233 
234     return cpu_lduw_mmuidx_ra(env, address, mmu_idx, GETPC());
235 }
236 
237 target_ulong helper_hyp_hlvx_wu(CPURISCVState *env, target_ulong address)
238 {
239     int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
240 
241     return cpu_ldl_mmuidx_ra(env, address, mmu_idx, GETPC());
242 }
243 
244 #endif /* !CONFIG_USER_ONLY */
245