diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2021-10-19 20:16:59 -0700 |
---|---|---|
committer | Alistair Francis <alistair@alistair23.me> | 2021-10-22 07:47:51 +1000 |
commit | 92371bd9033e5a50a7541d96ff8ad067930a4f93 (patch) | |
tree | b1410478fece6225eb4024182b5b0c1bbd2eeef0 | |
parent | db23e5d981ab22da0bfe1150f4828d08484b1fba (diff) |
target/riscv: Add MXL/SXL/UXL to TB_FLAGS
Begin adding support for switching XLEN at runtime. Extract the
effective XLEN from MISA and MSTATUS and store for use during translation.
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-6-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
-rw-r--r-- | target/riscv/cpu.c | 8 | ||||
-rw-r--r-- | target/riscv/cpu.h | 2 | ||||
-rw-r--r-- | target/riscv/cpu_helper.c | 33 | ||||
-rw-r--r-- | target/riscv/csr.c | 3 | ||||
-rw-r--r-- | target/riscv/translate.c | 2 |
5 files changed, 47 insertions, 1 deletions
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 3d144af1ab..dd9eccd68e 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -355,6 +355,14 @@ static void riscv_cpu_reset(DeviceState *dev) env->misa_mxl = env->misa_mxl_max; env->priv = PRV_M; env->mstatus &= ~(MSTATUS_MIE | MSTATUS_MPRV); + if (env->misa_mxl > MXL_RV32) { + /* + * The reset status of SXL/UXL is undefined, but mstatus is WARL + * and we must ensure that the value after init is valid for read. + */ + env->mstatus = set_field(env->mstatus, MSTATUS64_SXL, env->misa_mxl); + env->mstatus = set_field(env->mstatus, MSTATUS64_UXL, env->misa_mxl); + } env->mcause = 0; env->pc = env->resetvec; env->two_stage_lookup = false; diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index e23157b05c..a33dc30be8 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -395,6 +395,8 @@ FIELD(TB_FLAGS, VILL, 9, 1) /* Is a Hypervisor instruction load/store allowed? */ FIELD(TB_FLAGS, HLSX, 10, 1) FIELD(TB_FLAGS, MSTATUS_HS_FS, 11, 2) +/* The combination of MXL/SXL/UXL that applies to the current cpu mode. */ +FIELD(TB_FLAGS, XL, 13, 2) #ifdef TARGET_RISCV32 #define riscv_cpu_mxl(env) ((void)(env), MXL_RV32) diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 403f54171d..429afd1f48 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -35,6 +35,37 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch) #endif } +static RISCVMXL cpu_get_xl(CPURISCVState *env) +{ +#if defined(TARGET_RISCV32) + return MXL_RV32; +#elif defined(CONFIG_USER_ONLY) + return MXL_RV64; +#else + RISCVMXL xl = riscv_cpu_mxl(env); + + /* + * When emulating a 32-bit-only cpu, use RV32. + * When emulating a 64-bit cpu, and MXL has been reduced to RV32, + * MSTATUSH doesn't have UXL/SXL, therefore XLEN cannot be widened + * back to RV64 for lower privs. + */ + if (xl != MXL_RV32) { + switch (env->priv) { + case PRV_M: + break; + case PRV_U: + xl = get_field(env->mstatus, MSTATUS64_UXL); + break; + default: /* PRV_S | PRV_H */ + xl = get_field(env->mstatus, MSTATUS64_SXL); + break; + } + } + return xl; +#endif +} + void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc, target_ulong *cs_base, uint32_t *pflags) { @@ -78,6 +109,8 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc, } #endif + flags = FIELD_DP32(flags, TB_FLAGS, XL, cpu_get_xl(env)); + *pflags = flags; } diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 9c0753bc8b..c4a479ddd2 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -526,6 +526,9 @@ static RISCVException write_mstatus(CPURISCVState *env, int csrno, mstatus = set_field(mstatus, MSTATUS32_SD, dirty); } else { mstatus = set_field(mstatus, MSTATUS64_SD, dirty); + /* SXL and UXL fields are for now read only */ + mstatus = set_field(mstatus, MSTATUS64_SXL, MXL_RV64); + mstatus = set_field(mstatus, MSTATUS64_UXL, MXL_RV64); } env->mstatus = mstatus; diff --git a/target/riscv/translate.c b/target/riscv/translate.c index 0aa2122529..77cad9bc45 100644 --- a/target/riscv/translate.c +++ b/target/riscv/translate.c @@ -514,7 +514,6 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) #else ctx->virt_enabled = false; #endif - ctx->xl = env->misa_mxl; ctx->misa_ext = env->misa_ext; ctx->frm = -1; /* unknown rounding mode */ ctx->ext_ifencei = cpu->cfg.ext_ifencei; @@ -526,6 +525,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) 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->w = false; ctx->ntemp = 0; |