qemu/target/riscv/translate.c
Richard Henderson b550f89457 target/riscv: Compute mstatus.sd on demand
The position of this read-only field is dependent on the current xlen.
Rather than having to compute that difference in many places, compute
it only on read.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-16-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2021-10-22 23:35:47 +10:00

731 lines
20 KiB
C

/*
* RISC-V emulation for qemu: main translation routines.
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
*
* 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 "tcg/tcg-op.h"
#include "disas/disas.h"
#include "exec/cpu_ldst.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
#include "exec/helper-gen.h"
#include "exec/translator.h"
#include "exec/log.h"
#include "instmap.h"
/* global register indices */
static TCGv cpu_gpr[32], cpu_pc, cpu_vl;
static TCGv_i64 cpu_fpr[32]; /* assume F and D extensions */
static TCGv load_res;
static TCGv load_val;
#include "exec/gen-icount.h"
/*
* If an operation is being performed on less than TARGET_LONG_BITS,
* it may require the inputs to be sign- or zero-extended; which will
* depend on the exact operation being performed.
*/
typedef enum {
EXT_NONE,
EXT_SIGN,
EXT_ZERO,
} DisasExtend;
typedef struct DisasContext {
DisasContextBase base;
/* pc_succ_insn points to the instruction following base.pc_next */
target_ulong pc_succ_insn;
target_ulong priv_ver;
RISCVMXL xl;
uint32_t misa_ext;
uint32_t opcode;
uint32_t mstatus_fs;
uint32_t mstatus_hs_fs;
uint32_t mem_idx;
/* Remember the rounding mode encoded in the previous fp instruction,
which we have already installed into env->fp_status. Or -1 for
no previous fp instruction. Note that we exit the TB when writing
to any system register, which includes CSR_FRM, so we do not have
to reset this known value. */
int frm;
RISCVMXL ol;
bool virt_enabled;
bool ext_ifencei;
bool hlsx;
/* vector extension */
bool vill;
uint8_t lmul;
uint8_t sew;
uint16_t vlen;
uint16_t mlen;
bool vl_eq_vlmax;
uint8_t ntemp;
CPUState *cs;
TCGv zero;
/* Space for 3 operands plus 1 extra for address computation. */
TCGv temp[4];
} DisasContext;
static inline bool has_ext(DisasContext *ctx, uint32_t ext)
{
return ctx->misa_ext & ext;
}
#ifdef TARGET_RISCV32
#define get_xl(ctx) MXL_RV32
#elif defined(CONFIG_USER_ONLY)
#define get_xl(ctx) MXL_RV64
#else
#define get_xl(ctx) ((ctx)->xl)
#endif
/* The word size for this machine mode. */
static inline int __attribute__((unused)) get_xlen(DisasContext *ctx)
{
return 16 << get_xl(ctx);
}
/* The operation length, as opposed to the xlen. */
#ifdef TARGET_RISCV32
#define get_ol(ctx) MXL_RV32
#else
#define get_ol(ctx) ((ctx)->ol)
#endif
static inline int get_olen(DisasContext *ctx)
{
return 16 << get_ol(ctx);
}
/*
* RISC-V requires NaN-boxing of narrower width floating point values.
* This applies when a 32-bit value is assigned to a 64-bit FP register.
* For consistency and simplicity, we nanbox results even when the RVD
* extension is not present.
*/
static void gen_nanbox_s(TCGv_i64 out, TCGv_i64 in)
{
tcg_gen_ori_i64(out, in, MAKE_64BIT_MASK(32, 32));
}
/*
* A narrow n-bit operation, where n < FLEN, checks that input operands
* are correctly Nan-boxed, i.e., all upper FLEN - n bits are 1.
* If so, the least-significant bits of the input are used, otherwise the
* input value is treated as an n-bit canonical NaN (v2.2 section 9.2).
*
* Here, the result is always nan-boxed, even the canonical nan.
*/
static void gen_check_nanbox_s(TCGv_i64 out, TCGv_i64 in)
{
TCGv_i64 t_max = tcg_constant_i64(0xffffffff00000000ull);
TCGv_i64 t_nan = tcg_constant_i64(0xffffffff7fc00000ull);
tcg_gen_movcond_i64(TCG_COND_GEU, out, in, t_max, in, t_nan);
}
static void generate_exception(DisasContext *ctx, int excp)
{
tcg_gen_movi_tl(cpu_pc, ctx->base.pc_next);
gen_helper_raise_exception(cpu_env, tcg_constant_i32(excp));
ctx->base.is_jmp = DISAS_NORETURN;
}
static void generate_exception_mtval(DisasContext *ctx, int excp)
{
tcg_gen_movi_tl(cpu_pc, ctx->base.pc_next);
tcg_gen_st_tl(cpu_pc, cpu_env, offsetof(CPURISCVState, badaddr));
gen_helper_raise_exception(cpu_env, tcg_constant_i32(excp));
ctx->base.is_jmp = DISAS_NORETURN;
}
static void gen_exception_illegal(DisasContext *ctx)
{
generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
}
static void gen_exception_inst_addr_mis(DisasContext *ctx)
{
generate_exception_mtval(ctx, RISCV_EXCP_INST_ADDR_MIS);
}
static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
{
if (translator_use_goto_tb(&ctx->base, dest)) {
tcg_gen_goto_tb(n);
tcg_gen_movi_tl(cpu_pc, dest);
tcg_gen_exit_tb(ctx->base.tb, n);
} else {
tcg_gen_movi_tl(cpu_pc, dest);
tcg_gen_lookup_and_goto_ptr();
}
}
/*
* Wrappers for getting reg values.
*
* The $zero register does not have cpu_gpr[0] allocated -- we supply the
* constant zero as a source, and an uninitialized sink as destination.
*
* Further, we may provide an extension for word operations.
*/
static TCGv temp_new(DisasContext *ctx)
{
assert(ctx->ntemp < ARRAY_SIZE(ctx->temp));
return ctx->temp[ctx->ntemp++] = tcg_temp_new();
}
static TCGv get_gpr(DisasContext *ctx, int reg_num, DisasExtend ext)
{
TCGv t;
if (reg_num == 0) {
return ctx->zero;
}
switch (get_ol(ctx)) {
case MXL_RV32:
switch (ext) {
case EXT_NONE:
break;
case EXT_SIGN:
t = temp_new(ctx);
tcg_gen_ext32s_tl(t, cpu_gpr[reg_num]);
return t;
case EXT_ZERO:
t = temp_new(ctx);
tcg_gen_ext32u_tl(t, cpu_gpr[reg_num]);
return t;
default:
g_assert_not_reached();
}
break;
case MXL_RV64:
break;
default:
g_assert_not_reached();
}
return cpu_gpr[reg_num];
}
static TCGv dest_gpr(DisasContext *ctx, int reg_num)
{
if (reg_num == 0 || get_olen(ctx) < TARGET_LONG_BITS) {
return temp_new(ctx);
}
return cpu_gpr[reg_num];
}
static void gen_set_gpr(DisasContext *ctx, int reg_num, TCGv t)
{
if (reg_num != 0) {
switch (get_ol(ctx)) {
case MXL_RV32:
tcg_gen_ext32s_tl(cpu_gpr[reg_num], t);
break;
case MXL_RV64:
tcg_gen_mov_tl(cpu_gpr[reg_num], t);
break;
default:
g_assert_not_reached();
}
}
}
static void gen_jal(DisasContext *ctx, int rd, target_ulong imm)
{
target_ulong next_pc;
/* check misaligned: */
next_pc = ctx->base.pc_next + imm;
if (!has_ext(ctx, RVC)) {
if ((next_pc & 0x3) != 0) {
gen_exception_inst_addr_mis(ctx);
return;
}
}
if (rd != 0) {
tcg_gen_movi_tl(cpu_gpr[rd], ctx->pc_succ_insn);
}
gen_goto_tb(ctx, 0, ctx->base.pc_next + imm); /* must use this for safety */
ctx->base.is_jmp = DISAS_NORETURN;
}
#ifndef CONFIG_USER_ONLY
/* The states of mstatus_fs are:
* 0 = disabled, 1 = initial, 2 = clean, 3 = dirty
* We will have already diagnosed disabled state,
* and need to turn initial/clean into dirty.
*/
static void mark_fs_dirty(DisasContext *ctx)
{
TCGv tmp;
if (ctx->mstatus_fs != MSTATUS_FS) {
/* Remember the state change for the rest of the TB. */
ctx->mstatus_fs = MSTATUS_FS;
tmp = tcg_temp_new();
tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS);
tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
tcg_temp_free(tmp);
}
if (ctx->virt_enabled && ctx->mstatus_hs_fs != MSTATUS_FS) {
/* Remember the stage change for the rest of the TB. */
ctx->mstatus_hs_fs = MSTATUS_FS;
tmp = tcg_temp_new();
tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS);
tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
tcg_temp_free(tmp);
}
}
#else
static inline void mark_fs_dirty(DisasContext *ctx) { }
#endif
static void gen_set_rm(DisasContext *ctx, int rm)
{
if (ctx->frm == rm) {
return;
}
ctx->frm = rm;
gen_helper_set_rounding_mode(cpu_env, tcg_constant_i32(rm));
}
static int ex_plus_1(DisasContext *ctx, int nf)
{
return nf + 1;
}
#define EX_SH(amount) \
static int ex_shift_##amount(DisasContext *ctx, int imm) \
{ \
return imm << amount; \
}
EX_SH(1)
EX_SH(2)
EX_SH(3)
EX_SH(4)
EX_SH(12)
#define REQUIRE_EXT(ctx, ext) do { \
if (!has_ext(ctx, ext)) { \
return false; \
} \
} while (0)
#define REQUIRE_32BIT(ctx) do { \
if (get_xl(ctx) != MXL_RV32) { \
return false; \
} \
} while (0)
#define REQUIRE_64BIT(ctx) do { \
if (get_xl(ctx) < MXL_RV64) { \
return false; \
} \
} while (0)
static int ex_rvc_register(DisasContext *ctx, int reg)
{
return 8 + reg;
}
static int ex_rvc_shifti(DisasContext *ctx, int imm)
{
/* For RV128 a shamt of 0 means a shift by 64. */
return imm ? imm : 64;
}
/* Include the auto-generated decoder for 32 bit insn */
#include "decode-insn32.c.inc"
static bool gen_arith_imm_fn(DisasContext *ctx, arg_i *a, DisasExtend ext,
void (*func)(TCGv, TCGv, target_long))
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv src1 = get_gpr(ctx, a->rs1, ext);
func(dest, src1, a->imm);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_arith_imm_tl(DisasContext *ctx, arg_i *a, DisasExtend ext,
void (*func)(TCGv, TCGv, TCGv))
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv src1 = get_gpr(ctx, a->rs1, ext);
TCGv src2 = tcg_constant_tl(a->imm);
func(dest, src1, src2);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_arith(DisasContext *ctx, arg_r *a, DisasExtend ext,
void (*func)(TCGv, TCGv, TCGv))
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv src1 = get_gpr(ctx, a->rs1, ext);
TCGv src2 = get_gpr(ctx, a->rs2, ext);
func(dest, src1, src2);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_arith_per_ol(DisasContext *ctx, arg_r *a, DisasExtend ext,
void (*f_tl)(TCGv, TCGv, TCGv),
void (*f_32)(TCGv, TCGv, TCGv))
{
int olen = get_olen(ctx);
if (olen != TARGET_LONG_BITS) {
if (olen == 32) {
f_tl = f_32;
} else {
g_assert_not_reached();
}
}
return gen_arith(ctx, a, ext, f_tl);
}
static bool gen_shift_imm_fn(DisasContext *ctx, arg_shift *a, DisasExtend ext,
void (*func)(TCGv, TCGv, target_long))
{
TCGv dest, src1;
int max_len = get_olen(ctx);
if (a->shamt >= max_len) {
return false;
}
dest = dest_gpr(ctx, a->rd);
src1 = get_gpr(ctx, a->rs1, ext);
func(dest, src1, a->shamt);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_shift_imm_fn_per_ol(DisasContext *ctx, arg_shift *a,
DisasExtend ext,
void (*f_tl)(TCGv, TCGv, target_long),
void (*f_32)(TCGv, TCGv, target_long))
{
int olen = get_olen(ctx);
if (olen != TARGET_LONG_BITS) {
if (olen == 32) {
f_tl = f_32;
} else {
g_assert_not_reached();
}
}
return gen_shift_imm_fn(ctx, a, ext, f_tl);
}
static bool gen_shift_imm_tl(DisasContext *ctx, arg_shift *a, DisasExtend ext,
void (*func)(TCGv, TCGv, TCGv))
{
TCGv dest, src1, src2;
int max_len = get_olen(ctx);
if (a->shamt >= max_len) {
return false;
}
dest = dest_gpr(ctx, a->rd);
src1 = get_gpr(ctx, a->rs1, ext);
src2 = tcg_constant_tl(a->shamt);
func(dest, src1, src2);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_shift(DisasContext *ctx, arg_r *a, DisasExtend ext,
void (*func)(TCGv, TCGv, TCGv))
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv src1 = get_gpr(ctx, a->rs1, ext);
TCGv src2 = get_gpr(ctx, a->rs2, EXT_NONE);
TCGv ext2 = tcg_temp_new();
tcg_gen_andi_tl(ext2, src2, get_olen(ctx) - 1);
func(dest, src1, ext2);
gen_set_gpr(ctx, a->rd, dest);
tcg_temp_free(ext2);
return true;
}
static bool gen_shift_per_ol(DisasContext *ctx, arg_r *a, DisasExtend ext,
void (*f_tl)(TCGv, TCGv, TCGv),
void (*f_32)(TCGv, TCGv, TCGv))
{
int olen = get_olen(ctx);
if (olen != TARGET_LONG_BITS) {
if (olen == 32) {
f_tl = f_32;
} else {
g_assert_not_reached();
}
}
return gen_shift(ctx, a, ext, f_tl);
}
static bool gen_unary(DisasContext *ctx, arg_r2 *a, DisasExtend ext,
void (*func)(TCGv, TCGv))
{
TCGv dest = dest_gpr(ctx, a->rd);
TCGv src1 = get_gpr(ctx, a->rs1, ext);
func(dest, src1);
gen_set_gpr(ctx, a->rd, dest);
return true;
}
static bool gen_unary_per_ol(DisasContext *ctx, arg_r2 *a, DisasExtend ext,
void (*f_tl)(TCGv, TCGv),
void (*f_32)(TCGv, TCGv))
{
int olen = get_olen(ctx);
if (olen != TARGET_LONG_BITS) {
if (olen == 32) {
f_tl = f_32;
} else {
g_assert_not_reached();
}
}
return gen_unary(ctx, a, ext, f_tl);
}
static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc)
{
DisasContext *ctx = container_of(dcbase, DisasContext, base);
CPUState *cpu = ctx->cs;
CPURISCVState *env = cpu->env_ptr;
return cpu_ldl_code(env, pc);
}
/* Include insn module translation function */
#include "insn_trans/trans_rvi.c.inc"
#include "insn_trans/trans_rvm.c.inc"
#include "insn_trans/trans_rva.c.inc"
#include "insn_trans/trans_rvf.c.inc"
#include "insn_trans/trans_rvd.c.inc"
#include "insn_trans/trans_rvh.c.inc"
#include "insn_trans/trans_rvv.c.inc"
#include "insn_trans/trans_rvb.c.inc"
#include "insn_trans/trans_privileged.c.inc"
/* Include the auto-generated decoder for 16 bit insn */
#include "decode-insn16.c.inc"
static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
{
/* check for compressed insn */
if (extract16(opcode, 0, 2) != 3) {
if (!has_ext(ctx, RVC)) {
gen_exception_illegal(ctx);
} else {
ctx->pc_succ_insn = ctx->base.pc_next + 2;
if (!decode_insn16(ctx, opcode)) {
gen_exception_illegal(ctx);
}
}
} else {
uint32_t opcode32 = opcode;
opcode32 = deposit32(opcode32, 16, 16,
translator_lduw(env, &ctx->base,
ctx->base.pc_next + 2));
ctx->pc_succ_insn = ctx->base.pc_next + 4;
if (!decode_insn32(ctx, opcode32)) {
gen_exception_illegal(ctx);
}
}
}
static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
{
DisasContext *ctx = container_of(dcbase, DisasContext, base);
CPURISCVState *env = cs->env_ptr;
RISCVCPU *cpu = RISCV_CPU(cs);
uint32_t tb_flags = ctx->base.tb->flags;
ctx->pc_succ_insn = ctx->base.pc_first;
ctx->mem_idx = FIELD_EX32(tb_flags, TB_FLAGS, MEM_IDX);
ctx->mstatus_fs = tb_flags & TB_FLAGS_MSTATUS_FS;
ctx->priv_ver = env->priv_ver;
#if !defined(CONFIG_USER_ONLY)
if (riscv_has_ext(env, RVH)) {
ctx->virt_enabled = riscv_cpu_virt_enabled(env);
} else {
ctx->virt_enabled = false;
}
#else
ctx->virt_enabled = false;
#endif
ctx->misa_ext = env->misa_ext;
ctx->frm = -1; /* unknown rounding mode */
ctx->ext_ifencei = cpu->cfg.ext_ifencei;
ctx->vlen = cpu->cfg.vlen;
ctx->mstatus_hs_fs = FIELD_EX32(tb_flags, TB_FLAGS, MSTATUS_HS_FS);
ctx->hlsx = FIELD_EX32(tb_flags, TB_FLAGS, HLSX);
ctx->vill = FIELD_EX32(tb_flags, TB_FLAGS, VILL);
ctx->sew = FIELD_EX32(tb_flags, TB_FLAGS, SEW);
ctx->lmul = FIELD_EX32(tb_flags, TB_FLAGS, LMUL);
ctx->mlen = 1 << (ctx->sew + 3 - ctx->lmul);
ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
ctx->xl = FIELD_EX32(tb_flags, TB_FLAGS, XL);
ctx->cs = cs;
ctx->ntemp = 0;
memset(ctx->temp, 0, sizeof(ctx->temp));
ctx->zero = tcg_constant_tl(0);
}
static void riscv_tr_tb_start(DisasContextBase *db, CPUState *cpu)
{
}
static void riscv_tr_insn_start(DisasContextBase *dcbase, CPUState *cpu)
{
DisasContext *ctx = container_of(dcbase, DisasContext, base);
tcg_gen_insn_start(ctx->base.pc_next);
}
static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
{
DisasContext *ctx = container_of(dcbase, DisasContext, base);
CPURISCVState *env = cpu->env_ptr;
uint16_t opcode16 = translator_lduw(env, &ctx->base, ctx->base.pc_next);
ctx->ol = ctx->xl;
decode_opc(env, ctx, opcode16);
ctx->base.pc_next = ctx->pc_succ_insn;
for (int i = ctx->ntemp - 1; i >= 0; --i) {
tcg_temp_free(ctx->temp[i]);
ctx->temp[i] = NULL;
}
ctx->ntemp = 0;
if (ctx->base.is_jmp == DISAS_NEXT) {
target_ulong page_start;
page_start = ctx->base.pc_first & TARGET_PAGE_MASK;
if (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE) {
ctx->base.is_jmp = DISAS_TOO_MANY;
}
}
}
static void riscv_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
{
DisasContext *ctx = container_of(dcbase, DisasContext, base);
switch (ctx->base.is_jmp) {
case DISAS_TOO_MANY:
gen_goto_tb(ctx, 0, ctx->base.pc_next);
break;
case DISAS_NORETURN:
break;
default:
g_assert_not_reached();
}
}
static void riscv_tr_disas_log(const DisasContextBase *dcbase, CPUState *cpu)
{
#ifndef CONFIG_USER_ONLY
RISCVCPU *rvcpu = RISCV_CPU(cpu);
CPURISCVState *env = &rvcpu->env;
#endif
qemu_log("IN: %s\n", lookup_symbol(dcbase->pc_first));
#ifndef CONFIG_USER_ONLY
qemu_log("Priv: "TARGET_FMT_ld"; Virt: "TARGET_FMT_ld"\n", env->priv, env->virt);
#endif
log_target_disas(cpu, dcbase->pc_first, dcbase->tb->size);
}
static const TranslatorOps riscv_tr_ops = {
.init_disas_context = riscv_tr_init_disas_context,
.tb_start = riscv_tr_tb_start,
.insn_start = riscv_tr_insn_start,
.translate_insn = riscv_tr_translate_insn,
.tb_stop = riscv_tr_tb_stop,
.disas_log = riscv_tr_disas_log,
};
void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
{
DisasContext ctx;
translator_loop(&riscv_tr_ops, &ctx.base, cs, tb, max_insns);
}
void riscv_translate_init(void)
{
int i;
/*
* cpu_gpr[0] is a placeholder for the zero register. Do not use it.
* Use the gen_set_gpr and get_gpr helper functions when accessing regs,
* unless you specifically block reads/writes to reg 0.
*/
cpu_gpr[0] = NULL;
for (i = 1; i < 32; i++) {
cpu_gpr[i] = tcg_global_mem_new(cpu_env,
offsetof(CPURISCVState, gpr[i]), riscv_int_regnames[i]);
}
for (i = 0; i < 32; i++) {
cpu_fpr[i] = tcg_global_mem_new_i64(cpu_env,
offsetof(CPURISCVState, fpr[i]), riscv_fpr_regnames[i]);
}
cpu_pc = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, pc), "pc");
cpu_vl = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, vl), "vl");
load_res = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, load_res),
"load_res");
load_val = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, load_val),
"load_val");
}