xref: /openbmc/qemu/target/riscv/op_helper.c (revision 57cb2083)
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     int ret = riscv_csrrw(env, csr, &val, src, -1);
47 
48     if (ret < 0) {
49         riscv_raise_exception(env, -ret, GETPC());
50     }
51     return val;
52 }
53 
54 target_ulong helper_csrrs(CPURISCVState *env, target_ulong src,
55         target_ulong csr, target_ulong rs1_pass)
56 {
57     target_ulong val = 0;
58     int ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
59 
60     if (ret < 0) {
61         riscv_raise_exception(env, -ret, GETPC());
62     }
63     return val;
64 }
65 
66 target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
67         target_ulong csr, target_ulong rs1_pass)
68 {
69     target_ulong val = 0;
70     int ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
71 
72     if (ret < 0) {
73         riscv_raise_exception(env, -ret, GETPC());
74     }
75     return val;
76 }
77 
78 #ifndef CONFIG_USER_ONLY
79 
80 target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
81 {
82     target_ulong prev_priv, prev_virt, mstatus;
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     mstatus = env->mstatus;
98 
99     if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
100         /* We support Hypervisor extensions and virtulisation is disabled */
101         target_ulong hstatus = env->hstatus;
102 
103         prev_priv = get_field(mstatus, MSTATUS_SPP);
104         prev_virt = get_field(hstatus, HSTATUS_SPV);
105 
106         hstatus = set_field(hstatus, HSTATUS_SPV, 0);
107         mstatus = set_field(mstatus, MSTATUS_SPP, 0);
108         mstatus = set_field(mstatus, SSTATUS_SIE,
109                             get_field(mstatus, SSTATUS_SPIE));
110         mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
111 
112         env->mstatus = mstatus;
113         env->hstatus = hstatus;
114 
115         if (prev_virt) {
116             riscv_cpu_swap_hypervisor_regs(env);
117         }
118 
119         riscv_cpu_set_virt_enabled(env, prev_virt);
120     } else {
121         prev_priv = get_field(mstatus, MSTATUS_SPP);
122 
123         mstatus = set_field(mstatus, MSTATUS_SIE,
124                             get_field(mstatus, MSTATUS_SPIE));
125         mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
126         mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
127         env->mstatus = mstatus;
128     }
129 
130     riscv_cpu_set_mode(env, prev_priv);
131 
132     return retpc;
133 }
134 
135 target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
136 {
137     if (!(env->priv >= PRV_M)) {
138         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
139     }
140 
141     target_ulong retpc = env->mepc;
142     if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
143         riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
144     }
145 
146     target_ulong mstatus = env->mstatus;
147     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
148     target_ulong prev_virt = MSTATUS_MPV_ISSET(env);
149     mstatus = set_field(mstatus, MSTATUS_MIE,
150                         get_field(mstatus, MSTATUS_MPIE));
151     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
152     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
153 #ifdef TARGET_RISCV32
154     env->mstatush = set_field(env->mstatush, MSTATUS_MPV, 0);
155 #else
156     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
157 #endif
158     env->mstatus = mstatus;
159     riscv_cpu_set_mode(env, prev_priv);
160 
161     if (riscv_has_ext(env, RVH)) {
162         if (prev_virt) {
163             riscv_cpu_swap_hypervisor_regs(env);
164         }
165 
166         riscv_cpu_set_virt_enabled(env, prev_virt);
167     }
168 
169     return retpc;
170 }
171 
172 void helper_wfi(CPURISCVState *env)
173 {
174     CPUState *cs = env_cpu(env);
175 
176     if ((env->priv == PRV_S &&
177         get_field(env->mstatus, MSTATUS_TW)) ||
178         riscv_cpu_virt_enabled(env)) {
179         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
180     } else {
181         cs->halted = 1;
182         cs->exception_index = EXCP_HLT;
183         cpu_loop_exit(cs);
184     }
185 }
186 
187 void helper_tlb_flush(CPURISCVState *env)
188 {
189     CPUState *cs = env_cpu(env);
190     if (!(env->priv >= PRV_S) ||
191         (env->priv == PRV_S &&
192          get_field(env->mstatus, MSTATUS_TVM))) {
193         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
194     } else {
195         tlb_flush(cs);
196     }
197 }
198 
199 void helper_hyp_tlb_flush(CPURISCVState *env)
200 {
201     CPUState *cs = env_cpu(env);
202 
203     if (env->priv == PRV_M ||
204         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
205         tlb_flush(cs);
206         return;
207     }
208 
209     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
210 }
211 
212 target_ulong helper_hyp_load(CPURISCVState *env, target_ulong address,
213                              target_ulong attrs, target_ulong memop)
214 {
215     if (env->priv == PRV_M ||
216         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
217         (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
218             get_field(env->hstatus, HSTATUS_HU))) {
219         target_ulong pte;
220 
221         riscv_cpu_set_two_stage_lookup(env, true);
222 
223         switch (memop) {
224         case MO_SB:
225             pte = cpu_ldsb_data_ra(env, address, GETPC());
226             break;
227         case MO_UB:
228             pte = cpu_ldub_data_ra(env, address, GETPC());
229             break;
230         case MO_TESW:
231             pte = cpu_ldsw_data_ra(env, address, GETPC());
232             break;
233         case MO_TEUW:
234             pte = cpu_lduw_data_ra(env, address, GETPC());
235             break;
236         case MO_TESL:
237             pte = cpu_ldl_data_ra(env, address, GETPC());
238             break;
239         case MO_TEUL:
240             pte = cpu_ldl_data_ra(env, address, GETPC());
241             break;
242         case MO_TEQ:
243             pte = cpu_ldq_data_ra(env, address, GETPC());
244             break;
245         default:
246             g_assert_not_reached();
247         }
248 
249         riscv_cpu_set_two_stage_lookup(env, false);
250 
251         return pte;
252     }
253 
254     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
255     return 0;
256 }
257 
258 void helper_hyp_store(CPURISCVState *env, target_ulong address,
259                       target_ulong val, target_ulong attrs, target_ulong memop)
260 {
261     if (env->priv == PRV_M ||
262         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
263         (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
264             get_field(env->hstatus, HSTATUS_HU))) {
265         riscv_cpu_set_two_stage_lookup(env, true);
266 
267         switch (memop) {
268         case MO_SB:
269         case MO_UB:
270             cpu_stb_data_ra(env, address, val, GETPC());
271             break;
272         case MO_TESW:
273         case MO_TEUW:
274             cpu_stw_data_ra(env, address, val, GETPC());
275             break;
276         case MO_TESL:
277         case MO_TEUL:
278             cpu_stl_data_ra(env, address, val, GETPC());
279             break;
280         case MO_TEQ:
281             cpu_stq_data_ra(env, address, val, GETPC());
282             break;
283         default:
284             g_assert_not_reached();
285         }
286 
287         riscv_cpu_set_two_stage_lookup(env, false);
288 
289         return;
290     }
291 
292     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
293 }
294 
295 target_ulong helper_hyp_x_load(CPURISCVState *env, target_ulong address,
296                                target_ulong attrs, target_ulong memop)
297 {
298     if (env->priv == PRV_M ||
299         (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
300         (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
301             get_field(env->hstatus, HSTATUS_HU))) {
302         target_ulong pte;
303 
304         riscv_cpu_set_two_stage_lookup(env, true);
305 
306         switch (memop) {
307         case MO_TEUL:
308             pte = cpu_ldub_data_ra(env, address, GETPC());
309             break;
310         case MO_TEUW:
311             pte = cpu_lduw_data_ra(env, address, GETPC());
312             break;
313         default:
314             g_assert_not_reached();
315         }
316 
317         riscv_cpu_set_two_stage_lookup(env, false);
318 
319         return pte;
320     }
321 
322     riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
323     return 0;
324 }
325 
326 #endif /* !CONFIG_USER_ONLY */
327