Re: [PATCH v7 24/61] target/ppc/mmu_common.c: Split off real mode handling from get_physical_address_wtlb()

["Nicholas Piggin" <npiggin@gmail.com>]

On Mon May 13, 2024 at 9:27 AM AEST, BALATON Zoltan wrote:
> Add ppc_real_mode_xlate() to handle real mode translation and allow
> removing this case from ppc_jumbo_xlate().
>

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  target/ppc/mmu_common.c | 46 ++++++++++++++++++++++++-----------------
>  1 file changed, 27 insertions(+), 19 deletions(-)
>
> diff --git a/target/ppc/mmu_common.c b/target/ppc/mmu_common.c
> index 8599106f75..ab912da821 100644
> --- a/target/ppc/mmu_common.c
> +++ b/target/ppc/mmu_common.c
> @@ -1117,23 +1117,12 @@ int get_physical_address_wtlb(CPUPPCState *env, mmu_ctx_t *ctx,
>                                       MMUAccessType access_type, int type,
>                                       int mmu_idx)
>  {
> -    bool real_mode = (type == ACCESS_CODE) ? !FIELD_EX64(env->msr, MSR, IR)
> -                                           : !FIELD_EX64(env->msr, MSR, DR);
> -    if (real_mode) {
> -        ctx->raddr = eaddr;
> -        ctx->prot = PAGE_RWX;
> -        return 0;
> -    }
> -
>      switch (env->mmu_model) {
>      case POWERPC_MMU_SOFT_6xx:
>          return mmu6xx_get_physical_address(env, ctx, eaddr, access_type, type);
>      case POWERPC_MMU_SOFT_4xx:
>          return mmu40x_get_physical_address(env, &ctx->raddr, &ctx->prot, eaddr,
>                                             access_type);
> -    case POWERPC_MMU_REAL:
> -        cpu_abort(env_cpu(env),
> -                  "PowerPC in real mode do not do any translation\n");
>      default:
>          cpu_abort(env_cpu(env), "Unknown or invalid MMU model\n");
>      }
> @@ -1251,6 +1240,24 @@ static bool ppc_booke_xlate(PowerPCCPU *cpu, vaddr eaddr,
>      return false;
>  }
>  
> +static bool ppc_real_mode_xlate(PowerPCCPU *cpu, vaddr eaddr,
> +                                MMUAccessType access_type,
> +                                hwaddr *raddrp, int *psizep, int *protp)
> +{
> +    CPUPPCState *env = &cpu->env;
> +
> +    if (access_type == MMU_INST_FETCH ? !FIELD_EX64(env->msr, MSR, IR)
> +                                      : !FIELD_EX64(env->msr, MSR, DR)) {
> +        *raddrp = eaddr;
> +        *protp = PAGE_RWX;
> +        *psizep = TARGET_PAGE_BITS;
> +        return true;
> +    } else if (env->mmu_model == POWERPC_MMU_REAL) {
> +        cpu_abort(CPU(cpu), "PowerPC in real mode shold not do translation\n");
> +    }
> +    return false;
> +}
> +
>  /* Perform address translation */
>  /* TODO: Split this by mmu_model. */
>  static bool ppc_jumbo_xlate(PowerPCCPU *cpu, vaddr eaddr,
> @@ -1264,6 +1271,10 @@ static bool ppc_jumbo_xlate(PowerPCCPU *cpu, vaddr eaddr,
>      int type;
>      int ret;
>  
> +    if (ppc_real_mode_xlate(cpu, eaddr, access_type, raddrp, psizep, protp)) {
> +        return true;
> +    }
> +
>      if (access_type == MMU_INST_FETCH) {
>          /* code access */
>          type = ACCESS_CODE;
> @@ -1303,11 +1314,8 @@ static bool ppc_jumbo_xlate(PowerPCCPU *cpu, vaddr eaddr,
>                  env->spr[SPR_40x_DEAR] = eaddr;
>                  env->spr[SPR_40x_ESR] = 0x00000000;
>                  break;
> -            case POWERPC_MMU_REAL:
> -                cpu_abort(cs, "PowerPC in real mode should never raise "
> -                              "any MMU exceptions\n");
>              default:
> -                cpu_abort(cs, "Unknown or invalid MMU model\n");
> +                g_assert_not_reached();
>              }
>              break;
>          case -2:
> @@ -1359,11 +1367,8 @@ static bool ppc_jumbo_xlate(PowerPCCPU *cpu, vaddr eaddr,
>                      env->spr[SPR_40x_ESR] = 0x00000000;
>                  }
>                  break;
> -            case POWERPC_MMU_REAL:
> -                cpu_abort(cs, "PowerPC in real mode should never raise "
> -                              "any MMU exceptions\n");
>              default:
> -                cpu_abort(cs, "Unknown or invalid MMU model\n");
> +                g_assert_not_reached();
>              }
>              break;
>          case -2:
> @@ -1457,6 +1462,9 @@ bool ppc_xlate(PowerPCCPU *cpu, vaddr eaddr, MMUAccessType access_type,
>      case POWERPC_MMU_BOOKE206:
>          return ppc_booke_xlate(cpu, eaddr, access_type, raddrp,
>                                 psizep, protp, mmu_idx, guest_visible);
> +    case POWERPC_MMU_REAL:
> +        return ppc_real_mode_xlate(cpu, eaddr, access_type, raddrp, psizep,
> +                                   protp);
>      case POWERPC_MMU_MPC8xx:
>          cpu_abort(env_cpu(&cpu->env), "MPC8xx MMU model is not implemented\n");
>      default: