1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
|
/*
* RISC-V CPU helpers for qemu.
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
* Copyright (c) 2017-2018 SiFive, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "tcg-op.h"
#include "trace.h"
int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
{
#ifdef CONFIG_USER_ONLY
return 0;
#else
return env->priv;
#endif
}
#ifndef CONFIG_USER_ONLY
static int riscv_cpu_local_irq_pending(CPURISCVState *env)
{
target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
target_ulong pending = atomic_read(&env->mip) & env->mie;
target_ulong mie = env->priv < PRV_M || (env->priv == PRV_M && mstatus_mie);
target_ulong sie = env->priv < PRV_S || (env->priv == PRV_S && mstatus_sie);
target_ulong irqs = (pending & ~env->mideleg & -mie) |
(pending & env->mideleg & -sie);
if (irqs) {
return ctz64(irqs); /* since non-zero */
} else {
return EXCP_NONE; /* indicates no pending interrupt */
}
}
#endif
bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
#if !defined(CONFIG_USER_ONLY)
if (interrupt_request & CPU_INTERRUPT_HARD) {
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
int interruptno = riscv_cpu_local_irq_pending(env);
if (interruptno >= 0) {
cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
riscv_cpu_do_interrupt(cs);
return true;
}
}
#endif
return false;
}
#if !defined(CONFIG_USER_ONLY)
/* Return true is floating point support is currently enabled */
bool riscv_cpu_fp_enabled(CPURISCVState *env)
{
if (env->mstatus & MSTATUS_FS) {
return true;
}
return false;
}
int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
{
CPURISCVState *env = &cpu->env;
if (env->miclaim & interrupts) {
return -1;
} else {
env->miclaim |= interrupts;
return 0;
}
}
struct CpuAsyncInfo {
uint32_t new_mip;
};
static void riscv_cpu_update_mip_irqs_async(CPUState *target_cpu_state,
run_on_cpu_data data)
{
struct CpuAsyncInfo *info = (struct CpuAsyncInfo *) data.host_ptr;
if (info->new_mip) {
cpu_interrupt(target_cpu_state, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(target_cpu_state, CPU_INTERRUPT_HARD);
}
g_free(info);
}
uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
{
CPURISCVState *env = &cpu->env;
CPUState *cs = CPU(cpu);
struct CpuAsyncInfo *info;
uint32_t old, new, cmp = atomic_read(&env->mip);
do {
old = cmp;
new = (old & ~mask) | (value & mask);
cmp = atomic_cmpxchg(&env->mip, old, new);
} while (old != cmp);
info = g_new(struct CpuAsyncInfo, 1);
info->new_mip = new;
async_run_on_cpu(cs, riscv_cpu_update_mip_irqs_async,
RUN_ON_CPU_HOST_PTR(info));
return old;
}
void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
{
if (newpriv > PRV_M) {
g_assert_not_reached();
}
if (newpriv == PRV_H) {
newpriv = PRV_U;
}
/* tlb_flush is unnecessary as mode is contained in mmu_idx */
env->priv = newpriv;
/*
* Clear the load reservation - otherwise a reservation placed in one
* context/process can be used by another, resulting in an SC succeeding
* incorrectly. Version 2.2 of the ISA specification explicitly requires
* this behaviour, while later revisions say that the kernel "should" use
* an SC instruction to force the yielding of a load reservation on a
* preemptive context switch. As a result, do both.
*/
env->load_res = -1;
}
/* get_physical_address - get the physical address for this virtual address
*
* Do a page table walk to obtain the physical address corresponding to a
* virtual address. Returns 0 if the translation was successful
*
* Adapted from Spike's mmu_t::translate and mmu_t::walk
*
*/
static int get_physical_address(CPURISCVState *env, hwaddr *physical,
int *prot, target_ulong addr,
int access_type, int mmu_idx)
{
/* NOTE: the env->pc value visible here will not be
* correct, but the value visible to the exception handler
* (riscv_cpu_do_interrupt) is correct */
int mode = mmu_idx;
if (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
}
}
if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
}
*prot = 0;
hwaddr base;
int levels, ptidxbits, ptesize, vm, sum;
int mxr = get_field(env->mstatus, MSTATUS_MXR);
if (env->priv_ver >= PRIV_VERSION_1_10_0) {
base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
sum = get_field(env->mstatus, MSTATUS_SUM);
vm = get_field(env->satp, SATP_MODE);
switch (vm) {
case VM_1_10_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
case VM_1_10_SV39:
levels = 3; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV48:
levels = 4; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV57:
levels = 5; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_MBARE:
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
default:
g_assert_not_reached();
}
} else {
base = (hwaddr)(env->sptbr) << PGSHIFT;
sum = !get_field(env->mstatus, MSTATUS_PUM);
vm = get_field(env->mstatus, MSTATUS_VM);
switch (vm) {
case VM_1_09_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
case VM_1_09_SV39:
levels = 3; ptidxbits = 9; ptesize = 8; break;
case VM_1_09_SV48:
levels = 4; ptidxbits = 9; ptesize = 8; break;
case VM_1_09_MBARE:
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
default:
g_assert_not_reached();
}
}
CPUState *cs = env_cpu(env);
int va_bits = PGSHIFT + levels * ptidxbits;
target_ulong mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
target_ulong masked_msbs = (addr >> (va_bits - 1)) & mask;
if (masked_msbs != 0 && masked_msbs != mask) {
return TRANSLATE_FAIL;
}
int ptshift = (levels - 1) * ptidxbits;
int i;
#if !TCG_OVERSIZED_GUEST
restart:
#endif
for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
target_ulong idx = (addr >> (PGSHIFT + ptshift)) &
((1 << ptidxbits) - 1);
/* check that physical address of PTE is legal */
hwaddr pte_addr = base + idx * ptesize;
if (riscv_feature(env, RISCV_FEATURE_PMP) &&
!pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
1 << MMU_DATA_LOAD, PRV_S)) {
return TRANSLATE_PMP_FAIL;
}
#if defined(TARGET_RISCV32)
target_ulong pte = ldl_phys(cs->as, pte_addr);
#elif defined(TARGET_RISCV64)
target_ulong pte = ldq_phys(cs->as, pte_addr);
#endif
hwaddr ppn = pte >> PTE_PPN_SHIFT;
if (!(pte & PTE_V)) {
/* Invalid PTE */
return TRANSLATE_FAIL;
} else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
/* Inner PTE, continue walking */
base = ppn << PGSHIFT;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
/* Reserved leaf PTE flags: PTE_W */
return TRANSLATE_FAIL;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
/* Reserved leaf PTE flags: PTE_W + PTE_X */
return TRANSLATE_FAIL;
} else if ((pte & PTE_U) && ((mode != PRV_U) &&
(!sum || access_type == MMU_INST_FETCH))) {
/* User PTE flags when not U mode and mstatus.SUM is not set,
or the access type is an instruction fetch */
return TRANSLATE_FAIL;
} else if (!(pte & PTE_U) && (mode != PRV_S)) {
/* Supervisor PTE flags when not S mode */
return TRANSLATE_FAIL;
} else if (ppn & ((1ULL << ptshift) - 1)) {
/* Misaligned PPN */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
((pte & PTE_X) && mxr))) {
/* Read access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
/* Write access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
/* Fetch access check failed */
return TRANSLATE_FAIL;
} else {
/* if necessary, set accessed and dirty bits. */
target_ulong updated_pte = pte | PTE_A |
(access_type == MMU_DATA_STORE ? PTE_D : 0);
/* Page table updates need to be atomic with MTTCG enabled */
if (updated_pte != pte) {
/*
* - if accessed or dirty bits need updating, and the PTE is
* in RAM, then we do so atomically with a compare and swap.
* - if the PTE is in IO space or ROM, then it can't be updated
* and we return TRANSLATE_FAIL.
* - if the PTE changed by the time we went to update it, then
* it is no longer valid and we must re-walk the page table.
*/
MemoryRegion *mr;
hwaddr l = sizeof(target_ulong), addr1;
mr = address_space_translate(cs->as, pte_addr,
&addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
if (memory_region_is_ram(mr)) {
target_ulong *pte_pa =
qemu_map_ram_ptr(mr->ram_block, addr1);
#if TCG_OVERSIZED_GUEST
/* MTTCG is not enabled on oversized TCG guests so
* page table updates do not need to be atomic */
*pte_pa = pte = updated_pte;
#else
target_ulong old_pte =
atomic_cmpxchg(pte_pa, pte, updated_pte);
if (old_pte != pte) {
goto restart;
} else {
pte = updated_pte;
}
#endif
} else {
/* misconfigured PTE in ROM (AD bits are not preset) or
* PTE is in IO space and can't be updated atomically */
return TRANSLATE_FAIL;
}
}
/* for superpage mappings, make a fake leaf PTE for the TLB's
benefit. */
target_ulong vpn = addr >> PGSHIFT;
*physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
/* set permissions on the TLB entry */
if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
*prot |= PAGE_READ;
}
if ((pte & PTE_X)) {
*prot |= PAGE_EXEC;
}
/* add write permission on stores or if the page is already dirty,
so that we TLB miss on later writes to update the dirty bit */
if ((pte & PTE_W) &&
(access_type == MMU_DATA_STORE || (pte & PTE_D))) {
*prot |= PAGE_WRITE;
}
return TRANSLATE_SUCCESS;
}
}
return TRANSLATE_FAIL;
}
static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
MMUAccessType access_type, bool pmp_violation)
{
CPUState *cs = env_cpu(env);
int page_fault_exceptions =
(env->priv_ver >= PRIV_VERSION_1_10_0) &&
get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
!pmp_violation;
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
break;
case MMU_DATA_LOAD:
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
break;
case MMU_DATA_STORE:
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
break;
default:
g_assert_not_reached();
}
env->badaddr = address;
}
hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
hwaddr phys_addr;
int prot;
int mmu_idx = cpu_mmu_index(&cpu->env, false);
if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx)) {
return -1;
}
return phys_addr;
}
void riscv_cpu_unassigned_access(CPUState *cs, hwaddr addr, bool is_write,
bool is_exec, int unused, unsigned size)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (is_write) {
cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
} else {
cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
}
env->badaddr = addr;
riscv_raise_exception(&cpu->env, cs->exception_index, GETPC());
}
void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
MMUAccessType access_type, int mmu_idx,
uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
break;
default:
g_assert_not_reached();
}
env->badaddr = addr;
riscv_raise_exception(env, cs->exception_index, retaddr);
}
#endif
bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
#ifndef CONFIG_USER_ONLY
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
hwaddr pa = 0;
int prot;
bool pmp_violation = false;
int ret = TRANSLATE_FAIL;
int mode = mmu_idx;
qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
__func__, address, access_type, mmu_idx);
ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx);
if (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
}
}
qemu_log_mask(CPU_LOG_MMU,
"%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
" prot %d\n", __func__, address, ret, pa, prot);
if (riscv_feature(env, RISCV_FEATURE_PMP) &&
(ret == TRANSLATE_SUCCESS) &&
!pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
ret = TRANSLATE_PMP_FAIL;
}
if (ret == TRANSLATE_PMP_FAIL) {
pmp_violation = true;
}
if (ret == TRANSLATE_SUCCESS) {
tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
prot, mmu_idx, TARGET_PAGE_SIZE);
return true;
} else if (probe) {
return false;
} else {
raise_mmu_exception(env, address, access_type, pmp_violation);
riscv_raise_exception(env, cs->exception_index, retaddr);
}
#else
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
break;
}
cpu_loop_exit_restore(cs, retaddr);
#endif
}
/*
* Handle Traps
*
* Adapted from Spike's processor_t::take_trap.
*
*/
void riscv_cpu_do_interrupt(CPUState *cs)
{
#if !defined(CONFIG_USER_ONLY)
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
/* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
* so we mask off the MSB and separate into trap type and cause.
*/
bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
target_ulong deleg = async ? env->mideleg : env->medeleg;
target_ulong tval = 0;
static const int ecall_cause_map[] = {
[PRV_U] = RISCV_EXCP_U_ECALL,
[PRV_S] = RISCV_EXCP_S_ECALL,
[PRV_H] = RISCV_EXCP_H_ECALL,
[PRV_M] = RISCV_EXCP_M_ECALL
};
if (!async) {
/* set tval to badaddr for traps with address information */
switch (cause) {
case RISCV_EXCP_INST_ADDR_MIS:
case RISCV_EXCP_INST_ACCESS_FAULT:
case RISCV_EXCP_LOAD_ADDR_MIS:
case RISCV_EXCP_STORE_AMO_ADDR_MIS:
case RISCV_EXCP_LOAD_ACCESS_FAULT:
case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
case RISCV_EXCP_INST_PAGE_FAULT:
case RISCV_EXCP_LOAD_PAGE_FAULT:
case RISCV_EXCP_STORE_PAGE_FAULT:
tval = env->badaddr;
break;
default:
break;
}
/* ecall is dispatched as one cause so translate based on mode */
if (cause == RISCV_EXCP_U_ECALL) {
assert(env->priv <= 3);
cause = ecall_cause_map[env->priv];
}
}
trace_riscv_trap(env->mhartid, async, cause, env->pc, tval, cause < 16 ?
(async ? riscv_intr_names : riscv_excp_names)[cause] : "(unknown)");
if (env->priv <= PRV_S &&
cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
/* handle the trap in S-mode */
target_ulong s = env->mstatus;
s = set_field(s, MSTATUS_SPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE << env->priv));
s = set_field(s, MSTATUS_SPP, env->priv);
s = set_field(s, MSTATUS_SIE, 0);
env->mstatus = s;
env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
env->sepc = env->pc;
env->sbadaddr = tval;
env->pc = (env->stvec >> 2 << 2) +
((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_S);
} else {
/* handle the trap in M-mode */
target_ulong s = env->mstatus;
s = set_field(s, MSTATUS_MPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE << env->priv));
s = set_field(s, MSTATUS_MPP, env->priv);
s = set_field(s, MSTATUS_MIE, 0);
env->mstatus = s;
env->mcause = cause | ~(((target_ulong)-1) >> async);
env->mepc = env->pc;
env->mbadaddr = tval;
env->pc = (env->mtvec >> 2 << 2) +
((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_M);
}
/* NOTE: it is not necessary to yield load reservations here. It is only
* necessary for an SC from "another hart" to cause a load reservation
* to be yielded. Refer to the memory consistency model section of the
* RISC-V ISA Specification.
*/
#endif
cs->exception_index = EXCP_NONE; /* mark handled to qemu */
}
|