On Tue, Jun 25, 2019 at 3:09 AM Palmer Dabbelt <pal...@sifive.com> wrote:
>
> The various CSR instructions have been split out of the base ISA as part
> of the ratification process. This patch adds a Zicsr argument, which
> disables all the CSR instructions.
>
> Signed-off-by: Palmer Dabbelt <pal...@sifive.com>
> ---
> target/riscv/cpu.c | 1 +
> target/riscv/cpu.h | 1 +
> target/riscv/csr.c | 5 +++++
> 3 files changed, 7 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index bbad39a337b3..915b9e77df33 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -442,6 +442,7 @@ static Property riscv_cpu_properties[] = {
> DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
> DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
> DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
> + DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
> DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
> DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
> DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index ba551cd3082c..0adb307f3298 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -224,6 +224,7 @@ typedef struct RISCVCPU {
> bool ext_u;
> bool ext_counters;
> bool ext_ifencei;
> + bool ext_icsr;
>
> char *priv_spec;
> char *user_spec;
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index de67741f3648..ff988917b995 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -793,6 +793,7 @@ int riscv_csrrw(CPURISCVState *env, int csrno,
> target_ulong *ret_value,
> {
> int ret;
> target_ulong old_value;
> + RISCVCPU *cpu = env_archcpu(env);
>
> /* check privileges and return -1 if check fails */
> #if !defined(CONFIG_USER_ONLY)
> @@ -803,6 +804,10 @@ int riscv_csrrw(CPURISCVState *env, int csrno,
> target_ulong *ret_value,
> }
> #endif
>
> + /* ensure the CSR extension is enabled. */
> + if (!cpu->cfg.ext_icsr)
> + return -1;
QEMU style include curly braces around a single line if. Plus I think
it makes it less error prone. Can you add braces?
After that:
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> +
> /* check predicate */
> if (!csr_ops[csrno].predicate || csr_ops[csrno].predicate(env, csrno) <
> 0) {
> return -1;
> --
> 2.21.0
>
>
