diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-10-19 20:16:57 -0700 |
|---|---|---|
| committer | Alistair Francis <alistair@alistair23.me> | 2021-10-22 07:47:51 +1000 |
| commit | e91a7227cb802ea62ffa14707ebc2f588b01213d (patch) | |
| tree | 83e6aa01014f64717ecdcf2b0b7ee2b42ef44b72 /target/riscv/csr.c | |
| parent | 99bc874fb3a0709c36ae4e594a1262ce1660e698 (diff) | |
target/riscv: Split misa.mxl and misa.ext
The hw representation of misa.mxl is at the high bits of the
misa csr. Representing this in the same way inside QEMU
results in overly complex code trying to check that field.
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: 20211020031709.359469-4-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'target/riscv/csr.c')
| -rw-r--r-- | target/riscv/csr.c | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 23fbbd3216..d0c86a300d 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -39,7 +39,7 @@ static RISCVException fs(CPURISCVState *env, int csrno) { #if !defined(CONFIG_USER_ONLY) /* loose check condition for fcsr in vector extension */ - if ((csrno == CSR_FCSR) && (env->misa & RVV)) { + if ((csrno == CSR_FCSR) && (env->misa_ext & RVV)) { return RISCV_EXCP_NONE; } if (!env->debugger && !riscv_cpu_fp_enabled(env)) { @@ -51,7 +51,7 @@ static RISCVException fs(CPURISCVState *env, int csrno) static RISCVException vs(CPURISCVState *env, int csrno) { - if (env->misa & RVV) { + if (env->misa_ext & RVV) { return RISCV_EXCP_NONE; } return RISCV_EXCP_ILLEGAL_INST; @@ -557,7 +557,22 @@ static RISCVException write_mstatush(CPURISCVState *env, int csrno, static RISCVException read_misa(CPURISCVState *env, int csrno, target_ulong *val) { - *val = env->misa; + target_ulong misa; + + switch (env->misa_mxl) { + case MXL_RV32: + misa = (target_ulong)MXL_RV32 << 30; + break; +#ifdef TARGET_RISCV64 + case MXL_RV64: + misa = (target_ulong)MXL_RV64 << 62; + break; +#endif + default: + g_assert_not_reached(); + } + + *val = misa | env->misa_ext; return RISCV_EXCP_NONE; } @@ -583,8 +598,13 @@ static RISCVException write_misa(CPURISCVState *env, int csrno, return RISCV_EXCP_NONE; } + /* + * misa.MXL writes are not supported by QEMU. + * Drop writes to those bits. + */ + /* Mask extensions that are not supported by this hart */ - val &= env->misa_mask; + val &= env->misa_ext_mask; /* Mask extensions that are not supported by QEMU */ val &= (RVI | RVE | RVM | RVA | RVF | RVD | RVC | RVS | RVU); @@ -601,20 +621,14 @@ static RISCVException write_misa(CPURISCVState *env, int csrno, val &= ~RVC; } - /* misa.MXL writes are not supported by QEMU */ - if (riscv_cpu_is_32bit(env)) { - val = (env->misa & MISA32_MXL) | (val & ~MISA32_MXL); - } else { - val = (env->misa & MISA64_MXL) | (val & ~MISA64_MXL); + /* If nothing changed, do nothing. */ + if (val == env->misa_ext) { + return RISCV_EXCP_NONE; } /* flush translation cache */ - if (val != env->misa) { - tb_flush(env_cpu(env)); - } - - env->misa = val; - + tb_flush(env_cpu(env)); + env->misa_ext = val; return RISCV_EXCP_NONE; } |