LIU Zhiwei <zhiwei_liu@c-sky.com> 於 2021年4月9日 週五 下午3:51寫道：

> The xie CSR appears hardwired to zero in CLIC mode, replaced by separate
> memory-mapped interrupt enables (clicintie[i]). Writes to xie will be
> ignored and will not trap (i.e., no access faults).
>
> Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
> ---
>  target/riscv/csr.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 4c31364967..74bc7a08aa 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -23,6 +23,10 @@
>  #include "qemu/main-loop.h"
>  #include "exec/exec-all.h"
>
> +#if !defined(CONFIG_USER_ONLY)
> +#include "hw/intc/riscv_clic.h"
> +#endif
> +
>  /* CSR function table public API */
>  void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops)
>  {
> @@ -611,13 +615,17 @@ static int write_mideleg(CPURISCVState *env, int
> csrno, target_ulong val)
>
>  static int read_mie(CPURISCVState *env, int csrno, target_ulong *val)
>  {
> -    *val = env->mie;
> +    /* The xie CSR appears hardwired to zero in CLIC mode, (Section 4.3)
> */
> +    *val = riscv_clic_is_clic_mode(env) ? 0 : env->mie;
>      return 0;
>  }
>
>  static int write_mie(CPURISCVState *env, int csrno, target_ulong val)
>  {
> -    env->mie = (env->mie & ~all_ints) | (val & all_ints);
> +    /* Writes to xie will be ignored and will not trap. (Section 4.3) */
> +    if (!riscv_clic_is_clic_mode(env)) {
> +        env->mie = (env->mie & ~all_ints) | (val & all_ints);
> +    }
>      return 0;
>  }
>
> @@ -785,7 +793,8 @@ static int read_sie(CPURISCVState *env, int csrno,
> target_ulong *val)
>      if (riscv_cpu_virt_enabled(env)) {
>          read_vsie(env, CSR_VSIE, val);
>      } else {
> -        *val = env->mie & env->mideleg;
> +        /* The xie CSR appears hardwired to zero in CLIC mode. (Section
> 4.3) */
> +        *val = riscv_clic_is_clic_mode(env) ? 0 : env->mie & env->mideleg;
>      }
>      return 0;
>  }
> @@ -805,6 +814,10 @@ static int write_sie(CPURISCVState *env, int csrno,
> target_ulong val)
>      } else {
>          target_ulong newval = (env->mie & ~S_MODE_INTERRUPTS) |
>                                (val & S_MODE_INTERRUPTS);
> +        /* Writes to xie will be ignored and will not trap. (Section 4.3)
> */
> +        if (riscv_clic_is_clic_mode(env)) {
> +            return 0;
>
+        }
>

Minor:
This one can be omitted as write_sie() will eventually call write_mie().

Anyway,
Reviewed-by: Frank Chang <frank.chang@sifive.com>


>          write_mie(env, CSR_MIE, newval);
>      }
>
> --
> 2.25.1
>
>
>