2 * RISC-V CPU helpers for qemu.
5 * Copyright (c) 2017-2018 SiFive, Inc.
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.
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
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/>.
20 #include "qemu/osdep.h"
22 #include "qemu/main-loop.h"
24 #include "exec/exec-all.h"
25 #include "tcg/tcg-op.h"
28 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
30 #ifdef CONFIG_USER_ONLY
37 #ifndef CONFIG_USER_ONLY
38 static int riscv_cpu_local_irq_pending(CPURISCVState *env)
40 target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
41 target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
42 target_ulong pending = env->mip & env->mie;
43 target_ulong mie = env->priv < PRV_M || (env->priv == PRV_M && mstatus_mie);
44 target_ulong sie = env->priv < PRV_S || (env->priv == PRV_S && mstatus_sie);
45 target_ulong irqs = (pending & ~env->mideleg & -mie) |
46 (pending & env->mideleg & -sie);
49 return ctz64(irqs); /* since non-zero */
51 return EXCP_NONE; /* indicates no pending interrupt */
56 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
58 #if !defined(CONFIG_USER_ONLY)
59 if (interrupt_request & CPU_INTERRUPT_HARD) {
60 RISCVCPU *cpu = RISCV_CPU(cs);
61 CPURISCVState *env = &cpu->env;
62 int interruptno = riscv_cpu_local_irq_pending(env);
63 if (interruptno >= 0) {
64 cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
65 riscv_cpu_do_interrupt(cs);
73 #if !defined(CONFIG_USER_ONLY)
75 /* Return true is floating point support is currently enabled */
76 bool riscv_cpu_fp_enabled(CPURISCVState *env)
78 if (env->mstatus & MSTATUS_FS) {
85 bool riscv_cpu_virt_enabled(CPURISCVState *env)
87 if (!riscv_has_ext(env, RVH)) {
91 return get_field(env->virt, VIRT_ONOFF);
94 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
96 if (!riscv_has_ext(env, RVH)) {
100 env->virt = set_field(env->virt, VIRT_ONOFF, enable);
103 bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
105 if (!riscv_has_ext(env, RVH)) {
109 return get_field(env->virt, FORCE_HS_EXCEP);
112 void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
114 if (!riscv_has_ext(env, RVH)) {
118 env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
121 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
123 CPURISCVState *env = &cpu->env;
124 if (env->miclaim & interrupts) {
127 env->miclaim |= interrupts;
132 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
134 CPURISCVState *env = &cpu->env;
135 CPUState *cs = CPU(cpu);
136 uint32_t old = env->mip;
139 if (!qemu_mutex_iothread_locked()) {
141 qemu_mutex_lock_iothread();
144 env->mip = (env->mip & ~mask) | (value & mask);
147 cpu_interrupt(cs, CPU_INTERRUPT_HARD);
149 cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
153 qemu_mutex_unlock_iothread();
159 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
161 if (newpriv > PRV_M) {
162 g_assert_not_reached();
164 if (newpriv == PRV_H) {
167 /* tlb_flush is unnecessary as mode is contained in mmu_idx */
171 * Clear the load reservation - otherwise a reservation placed in one
172 * context/process can be used by another, resulting in an SC succeeding
173 * incorrectly. Version 2.2 of the ISA specification explicitly requires
174 * this behaviour, while later revisions say that the kernel "should" use
175 * an SC instruction to force the yielding of a load reservation on a
176 * preemptive context switch. As a result, do both.
181 /* get_physical_address - get the physical address for this virtual address
183 * Do a page table walk to obtain the physical address corresponding to a
184 * virtual address. Returns 0 if the translation was successful
186 * Adapted from Spike's mmu_t::translate and mmu_t::walk
189 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
190 int *prot, target_ulong addr,
191 int access_type, int mmu_idx)
193 /* NOTE: the env->pc value visible here will not be
194 * correct, but the value visible to the exception handler
195 * (riscv_cpu_do_interrupt) is correct */
197 MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
200 if (mode == PRV_M && access_type != MMU_INST_FETCH) {
201 if (get_field(env->mstatus, MSTATUS_MPRV)) {
202 mode = get_field(env->mstatus, MSTATUS_MPP);
206 if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
208 *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
209 return TRANSLATE_SUCCESS;
215 int levels, ptidxbits, ptesize, vm, sum;
216 int mxr = get_field(env->mstatus, MSTATUS_MXR);
218 if (env->priv_ver >= PRIV_VERSION_1_10_0) {
219 base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
220 sum = get_field(env->mstatus, MSTATUS_SUM);
221 vm = get_field(env->satp, SATP_MODE);
224 levels = 2; ptidxbits = 10; ptesize = 4; break;
226 levels = 3; ptidxbits = 9; ptesize = 8; break;
228 levels = 4; ptidxbits = 9; ptesize = 8; break;
230 levels = 5; ptidxbits = 9; ptesize = 8; break;
233 *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
234 return TRANSLATE_SUCCESS;
236 g_assert_not_reached();
239 base = (hwaddr)(env->sptbr) << PGSHIFT;
240 sum = !get_field(env->mstatus, MSTATUS_PUM);
241 vm = get_field(env->mstatus, MSTATUS_VM);
244 levels = 2; ptidxbits = 10; ptesize = 4; break;
246 levels = 3; ptidxbits = 9; ptesize = 8; break;
248 levels = 4; ptidxbits = 9; ptesize = 8; break;
251 *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
252 return TRANSLATE_SUCCESS;
254 g_assert_not_reached();
258 CPUState *cs = env_cpu(env);
259 int va_bits = PGSHIFT + levels * ptidxbits;
260 target_ulong mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
261 target_ulong masked_msbs = (addr >> (va_bits - 1)) & mask;
262 if (masked_msbs != 0 && masked_msbs != mask) {
263 return TRANSLATE_FAIL;
266 int ptshift = (levels - 1) * ptidxbits;
269 #if !TCG_OVERSIZED_GUEST
272 for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
273 target_ulong idx = (addr >> (PGSHIFT + ptshift)) &
274 ((1 << ptidxbits) - 1);
276 /* check that physical address of PTE is legal */
277 hwaddr pte_addr = base + idx * ptesize;
279 if (riscv_feature(env, RISCV_FEATURE_PMP) &&
280 !pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
281 1 << MMU_DATA_LOAD, PRV_S)) {
282 return TRANSLATE_PMP_FAIL;
285 #if defined(TARGET_RISCV32)
286 target_ulong pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
287 #elif defined(TARGET_RISCV64)
288 target_ulong pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
290 if (res != MEMTX_OK) {
291 return TRANSLATE_FAIL;
294 hwaddr ppn = pte >> PTE_PPN_SHIFT;
296 if (!(pte & PTE_V)) {
298 return TRANSLATE_FAIL;
299 } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
300 /* Inner PTE, continue walking */
301 base = ppn << PGSHIFT;
302 } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
303 /* Reserved leaf PTE flags: PTE_W */
304 return TRANSLATE_FAIL;
305 } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
306 /* Reserved leaf PTE flags: PTE_W + PTE_X */
307 return TRANSLATE_FAIL;
308 } else if ((pte & PTE_U) && ((mode != PRV_U) &&
309 (!sum || access_type == MMU_INST_FETCH))) {
310 /* User PTE flags when not U mode and mstatus.SUM is not set,
311 or the access type is an instruction fetch */
312 return TRANSLATE_FAIL;
313 } else if (!(pte & PTE_U) && (mode != PRV_S)) {
314 /* Supervisor PTE flags when not S mode */
315 return TRANSLATE_FAIL;
316 } else if (ppn & ((1ULL << ptshift) - 1)) {
318 return TRANSLATE_FAIL;
319 } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
320 ((pte & PTE_X) && mxr))) {
321 /* Read access check failed */
322 return TRANSLATE_FAIL;
323 } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
324 /* Write access check failed */
325 return TRANSLATE_FAIL;
326 } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
327 /* Fetch access check failed */
328 return TRANSLATE_FAIL;
330 /* if necessary, set accessed and dirty bits. */
331 target_ulong updated_pte = pte | PTE_A |
332 (access_type == MMU_DATA_STORE ? PTE_D : 0);
334 /* Page table updates need to be atomic with MTTCG enabled */
335 if (updated_pte != pte) {
337 * - if accessed or dirty bits need updating, and the PTE is
338 * in RAM, then we do so atomically with a compare and swap.
339 * - if the PTE is in IO space or ROM, then it can't be updated
340 * and we return TRANSLATE_FAIL.
341 * - if the PTE changed by the time we went to update it, then
342 * it is no longer valid and we must re-walk the page table.
345 hwaddr l = sizeof(target_ulong), addr1;
346 mr = address_space_translate(cs->as, pte_addr,
347 &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
348 if (memory_region_is_ram(mr)) {
349 target_ulong *pte_pa =
350 qemu_map_ram_ptr(mr->ram_block, addr1);
351 #if TCG_OVERSIZED_GUEST
352 /* MTTCG is not enabled on oversized TCG guests so
353 * page table updates do not need to be atomic */
354 *pte_pa = pte = updated_pte;
356 target_ulong old_pte =
357 atomic_cmpxchg(pte_pa, pte, updated_pte);
358 if (old_pte != pte) {
365 /* misconfigured PTE in ROM (AD bits are not preset) or
366 * PTE is in IO space and can't be updated atomically */
367 return TRANSLATE_FAIL;
371 /* for superpage mappings, make a fake leaf PTE for the TLB's
373 target_ulong vpn = addr >> PGSHIFT;
374 *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
376 /* set permissions on the TLB entry */
377 if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
383 /* add write permission on stores or if the page is already dirty,
384 so that we TLB miss on later writes to update the dirty bit */
386 (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
389 return TRANSLATE_SUCCESS;
392 return TRANSLATE_FAIL;
395 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
396 MMUAccessType access_type, bool pmp_violation)
398 CPUState *cs = env_cpu(env);
399 int page_fault_exceptions =
400 (env->priv_ver >= PRIV_VERSION_1_10_0) &&
401 get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
403 switch (access_type) {
405 cs->exception_index = page_fault_exceptions ?
406 RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
409 cs->exception_index = page_fault_exceptions ?
410 RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
413 cs->exception_index = page_fault_exceptions ?
414 RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
417 g_assert_not_reached();
419 env->badaddr = address;
422 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
424 RISCVCPU *cpu = RISCV_CPU(cs);
427 int mmu_idx = cpu_mmu_index(&cpu->env, false);
429 if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx)) {
435 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
436 vaddr addr, unsigned size,
437 MMUAccessType access_type,
438 int mmu_idx, MemTxAttrs attrs,
439 MemTxResult response, uintptr_t retaddr)
441 RISCVCPU *cpu = RISCV_CPU(cs);
442 CPURISCVState *env = &cpu->env;
444 if (access_type == MMU_DATA_STORE) {
445 cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
447 cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
451 riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
454 void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
455 MMUAccessType access_type, int mmu_idx,
458 RISCVCPU *cpu = RISCV_CPU(cs);
459 CPURISCVState *env = &cpu->env;
460 switch (access_type) {
462 cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
465 cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
468 cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
471 g_assert_not_reached();
474 riscv_raise_exception(env, cs->exception_index, retaddr);
478 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
479 MMUAccessType access_type, int mmu_idx,
480 bool probe, uintptr_t retaddr)
482 RISCVCPU *cpu = RISCV_CPU(cs);
483 CPURISCVState *env = &cpu->env;
484 #ifndef CONFIG_USER_ONLY
487 bool pmp_violation = false;
488 int ret = TRANSLATE_FAIL;
491 qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
492 __func__, address, access_type, mmu_idx);
494 ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx);
496 if (mode == PRV_M && access_type != MMU_INST_FETCH) {
497 if (get_field(env->mstatus, MSTATUS_MPRV)) {
498 mode = get_field(env->mstatus, MSTATUS_MPP);
502 qemu_log_mask(CPU_LOG_MMU,
503 "%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
504 " prot %d\n", __func__, address, ret, pa, prot);
506 if (riscv_feature(env, RISCV_FEATURE_PMP) &&
507 (ret == TRANSLATE_SUCCESS) &&
508 !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
509 ret = TRANSLATE_PMP_FAIL;
511 if (ret == TRANSLATE_PMP_FAIL) {
512 pmp_violation = true;
514 if (ret == TRANSLATE_SUCCESS) {
515 tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
516 prot, mmu_idx, TARGET_PAGE_SIZE);
521 raise_mmu_exception(env, address, access_type, pmp_violation);
522 riscv_raise_exception(env, cs->exception_index, retaddr);
525 switch (access_type) {
527 cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
530 cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
533 cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
536 g_assert_not_reached();
538 env->badaddr = address;
539 cpu_loop_exit_restore(cs, retaddr);
546 * Adapted from Spike's processor_t::take_trap.
549 void riscv_cpu_do_interrupt(CPUState *cs)
551 #if !defined(CONFIG_USER_ONLY)
553 RISCVCPU *cpu = RISCV_CPU(cs);
554 CPURISCVState *env = &cpu->env;
556 /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
557 * so we mask off the MSB and separate into trap type and cause.
559 bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
560 target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
561 target_ulong deleg = async ? env->mideleg : env->medeleg;
562 target_ulong tval = 0;
564 static const int ecall_cause_map[] = {
565 [PRV_U] = RISCV_EXCP_U_ECALL,
566 [PRV_S] = RISCV_EXCP_S_ECALL,
567 [PRV_H] = RISCV_EXCP_VS_ECALL,
568 [PRV_M] = RISCV_EXCP_M_ECALL
572 /* set tval to badaddr for traps with address information */
574 case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
575 case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
576 case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
577 case RISCV_EXCP_INST_ADDR_MIS:
578 case RISCV_EXCP_INST_ACCESS_FAULT:
579 case RISCV_EXCP_LOAD_ADDR_MIS:
580 case RISCV_EXCP_STORE_AMO_ADDR_MIS:
581 case RISCV_EXCP_LOAD_ACCESS_FAULT:
582 case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
583 case RISCV_EXCP_INST_PAGE_FAULT:
584 case RISCV_EXCP_LOAD_PAGE_FAULT:
585 case RISCV_EXCP_STORE_PAGE_FAULT:
591 /* ecall is dispatched as one cause so translate based on mode */
592 if (cause == RISCV_EXCP_U_ECALL) {
593 assert(env->priv <= 3);
594 cause = ecall_cause_map[env->priv];
598 trace_riscv_trap(env->mhartid, async, cause, env->pc, tval, cause < 23 ?
599 (async ? riscv_intr_names : riscv_excp_names)[cause] : "(unknown)");
601 if (env->priv <= PRV_S &&
602 cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
603 /* handle the trap in S-mode */
604 target_ulong s = env->mstatus;
605 s = set_field(s, MSTATUS_SPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
606 get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE << env->priv));
607 s = set_field(s, MSTATUS_SPP, env->priv);
608 s = set_field(s, MSTATUS_SIE, 0);
610 env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
612 env->sbadaddr = tval;
613 env->pc = (env->stvec >> 2 << 2) +
614 ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
615 riscv_cpu_set_mode(env, PRV_S);
617 /* handle the trap in M-mode */
618 target_ulong s = env->mstatus;
619 s = set_field(s, MSTATUS_MPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
620 get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE << env->priv));
621 s = set_field(s, MSTATUS_MPP, env->priv);
622 s = set_field(s, MSTATUS_MIE, 0);
624 env->mcause = cause | ~(((target_ulong)-1) >> async);
626 env->mbadaddr = tval;
627 env->pc = (env->mtvec >> 2 << 2) +
628 ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
629 riscv_cpu_set_mode(env, PRV_M);
632 /* NOTE: it is not necessary to yield load reservations here. It is only
633 * necessary for an SC from "another hart" to cause a load reservation
634 * to be yielded. Refer to the memory consistency model section of the
635 * RISC-V ISA Specification.
639 cs->exception_index = EXCP_NONE; /* mark handled to qemu */