qemu/target/riscv/op_helper.c
Richard Henderson a974879b45 target/riscv: Reorg csr instructions
Introduce csrr and csrw helpers, for read-only and write-only insns.

Note that we do not properly implement this in riscv_csrrw, in that
we cannot distinguish true read-only (rs1 == 0) from any other zero
write_mask another source register -- this should still raise an
exception for read-only registers.

Only issue gen_io_start for CF_USE_ICOUNT.
Use ctx->zero for csrrc.
Use get_gpr and dest_gpr.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210823195529.560295-19-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2021-09-01 11:59:12 +10:00

250 lines
7.5 KiB
C

/*
* RISC-V Emulation 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 "cpu.h"
#include "qemu/main-loop.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
/* Exceptions processing helpers */
void QEMU_NORETURN riscv_raise_exception(CPURISCVState *env,
uint32_t exception, uintptr_t pc)
{
CPUState *cs = env_cpu(env);
cs->exception_index = exception;
cpu_loop_exit_restore(cs, pc);
}
void helper_raise_exception(CPURISCVState *env, uint32_t exception)
{
riscv_raise_exception(env, exception, 0);
}
target_ulong helper_csrr(CPURISCVState *env, int csr)
{
target_ulong val = 0;
RISCVException ret = riscv_csrrw(env, csr, &val, 0, 0);
if (ret != RISCV_EXCP_NONE) {
riscv_raise_exception(env, ret, GETPC());
}
return val;
}
void helper_csrw(CPURISCVState *env, int csr, target_ulong src)
{
RISCVException ret = riscv_csrrw(env, csr, NULL, src, -1);
if (ret != RISCV_EXCP_NONE) {
riscv_raise_exception(env, ret, GETPC());
}
}
target_ulong helper_csrrw(CPURISCVState *env, int csr,
target_ulong src, target_ulong write_mask)
{
target_ulong val = 0;
RISCVException ret = riscv_csrrw(env, csr, &val, src, write_mask);
if (ret != RISCV_EXCP_NONE) {
riscv_raise_exception(env, ret, GETPC());
}
return val;
}
#ifndef CONFIG_USER_ONLY
target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
{
uint64_t mstatus;
target_ulong prev_priv, prev_virt;
if (!(env->priv >= PRV_S)) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
target_ulong retpc = env->sepc;
if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
}
if (get_field(env->mstatus, MSTATUS_TSR) && !(env->priv >= PRV_M)) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
get_field(env->hstatus, HSTATUS_VTSR)) {
riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
}
mstatus = env->mstatus;
if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
/* We support Hypervisor extensions and virtulisation is disabled */
target_ulong hstatus = env->hstatus;
prev_priv = get_field(mstatus, MSTATUS_SPP);
prev_virt = get_field(hstatus, HSTATUS_SPV);
hstatus = set_field(hstatus, HSTATUS_SPV, 0);
mstatus = set_field(mstatus, MSTATUS_SPP, 0);
mstatus = set_field(mstatus, SSTATUS_SIE,
get_field(mstatus, SSTATUS_SPIE));
mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
env->mstatus = mstatus;
env->hstatus = hstatus;
if (prev_virt) {
riscv_cpu_swap_hypervisor_regs(env);
}
riscv_cpu_set_virt_enabled(env, prev_virt);
} else {
prev_priv = get_field(mstatus, MSTATUS_SPP);
mstatus = set_field(mstatus, MSTATUS_SIE,
get_field(mstatus, MSTATUS_SPIE));
mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
env->mstatus = mstatus;
}
riscv_cpu_set_mode(env, prev_priv);
return retpc;
}
target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
{
if (!(env->priv >= PRV_M)) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
target_ulong retpc = env->mepc;
if (!riscv_has_ext(env, RVC) && (retpc & 0x3)) {
riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
}
uint64_t mstatus = env->mstatus;
target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
if (!pmp_get_num_rules(env) && (prev_priv != PRV_M)) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV);
mstatus = set_field(mstatus, MSTATUS_MIE,
get_field(mstatus, MSTATUS_MPIE));
mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
mstatus = set_field(mstatus, MSTATUS_MPV, 0);
env->mstatus = mstatus;
riscv_cpu_set_mode(env, prev_priv);
if (riscv_has_ext(env, RVH)) {
if (prev_virt) {
riscv_cpu_swap_hypervisor_regs(env);
}
riscv_cpu_set_virt_enabled(env, prev_virt);
}
return retpc;
}
void helper_wfi(CPURISCVState *env)
{
CPUState *cs = env_cpu(env);
bool rvs = riscv_has_ext(env, RVS);
bool prv_u = env->priv == PRV_U;
bool prv_s = env->priv == PRV_S;
if (((prv_s || (!rvs && prv_u)) && get_field(env->mstatus, MSTATUS_TW)) ||
(rvs && prv_u && !riscv_cpu_virt_enabled(env))) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
} else if (riscv_cpu_virt_enabled(env) && (prv_u ||
(prv_s && get_field(env->hstatus, HSTATUS_VTW)))) {
riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
} else {
cs->halted = 1;
cs->exception_index = EXCP_HLT;
cpu_loop_exit(cs);
}
}
void helper_tlb_flush(CPURISCVState *env)
{
CPUState *cs = env_cpu(env);
if (!(env->priv >= PRV_S) ||
(env->priv == PRV_S &&
get_field(env->mstatus, MSTATUS_TVM))) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
} else if (riscv_has_ext(env, RVH) && riscv_cpu_virt_enabled(env) &&
get_field(env->hstatus, HSTATUS_VTVM)) {
riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
} else {
tlb_flush(cs);
}
}
void helper_hyp_tlb_flush(CPURISCVState *env)
{
CPUState *cs = env_cpu(env);
if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
}
if (env->priv == PRV_M ||
(env->priv == PRV_S && !riscv_cpu_virt_enabled(env))) {
tlb_flush(cs);
return;
}
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
void helper_hyp_gvma_tlb_flush(CPURISCVState *env)
{
if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env) &&
get_field(env->mstatus, MSTATUS_TVM)) {
riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
}
helper_hyp_tlb_flush(env);
}
target_ulong helper_hyp_hlvx_hu(CPURISCVState *env, target_ulong address)
{
int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
return cpu_lduw_mmuidx_ra(env, address, mmu_idx, GETPC());
}
target_ulong helper_hyp_hlvx_wu(CPURISCVState *env, target_ulong address)
{
int mmu_idx = cpu_mmu_index(env, true) | TB_FLAGS_PRIV_HYP_ACCESS_MASK;
return cpu_ldl_mmuidx_ra(env, address, mmu_idx, GETPC());
}
#endif /* !CONFIG_USER_ONLY */