Re: [PATCH v4 19/33] target/ppc/mmu_common.c: Don't use mmu_ctx_t for mmu40x_get_physical_address()

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

On Thu May 9, 2024 at 9:36 AM AEST, BALATON Zoltan wrote:
> mmu40x_get_physical_address() only uses the raddr and prot fields from
> mmu_ctx_t. Pass these directly instead of using a ctx struct.
>

> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  target/ppc/mmu_common.c | 38 ++++++++++++++++----------------------
>  1 file changed, 16 insertions(+), 22 deletions(-)
>
> diff --git a/target/ppc/mmu_common.c b/target/ppc/mmu_common.c
> index 6570b280ca..c5ef02f05e 100644
> --- a/target/ppc/mmu_common.c
> +++ b/target/ppc/mmu_common.c
> @@ -519,20 +519,19 @@ int ppcemb_tlb_search(CPUPPCState *env, target_ulong address, uint32_t pid)
>      return -1;
>  }
>  
> -static int mmu40x_get_physical_address(CPUPPCState *env, mmu_ctx_t *ctx,
> -                                       target_ulong address,
> +static int mmu40x_get_physical_address(CPUPPCState *env, hwaddr *raddr,
> +                                       int *prot, target_ulong address,
>                                         MMUAccessType access_type)
>  {
>      ppcemb_tlb_t *tlb;
> -    hwaddr raddr;
>      int i, ret, zsel, zpr, pr;
>  
>      ret = -1;
> -    raddr = (hwaddr)-1ULL;
> +    *prot = 0;

This is still doing some sneaky used-uninit things which I would
rather not without a comment, but okay we can try untangle things
more after this series.

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

>      pr = FIELD_EX64(env->msr, MSR, PR);
>      for (i = 0; i < env->nb_tlb; i++) {
>          tlb = &env->tlb.tlbe[i];
> -        if (!ppcemb_tlb_check(env, tlb, &raddr, address,
> +        if (!ppcemb_tlb_check(env, tlb, raddr, address,
>                                env->spr[SPR_40x_PID], i)) {
>              continue;
>          }
> @@ -550,40 +549,34 @@ static int mmu40x_get_physical_address(CPUPPCState *env, mmu_ctx_t *ctx,
>              /* fall through */
>          case 0x3:
>              /* All accesses granted */
> -            ctx->prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
> +            *prot = PAGE_RWX;
>              ret = 0;
>              break;
> +
>          case 0x0:
>              if (pr != 0) {
>                  /* Raise Zone protection fault.  */
>                  env->spr[SPR_40x_ESR] = 1 << 22;
> -                ctx->prot = 0;
> +                *prot = 0;
>                  ret = -2;
>                  break;
>              }
>              /* fall through */
>          case 0x1:
> -        check_perms:
> +check_perms:
>              /* Check from TLB entry */
> -            ctx->prot = tlb->prot;
> -            ret = check_prot(ctx->prot, access_type);
> +            *prot = tlb->prot;
> +            ret = check_prot(*prot, access_type);
>              if (ret == -2) {
>                  env->spr[SPR_40x_ESR] = 0;
>              }
>              break;
>          }
> -        if (ret >= 0) {
> -            ctx->raddr = raddr;
> -            qemu_log_mask(CPU_LOG_MMU, "%s: access granted " TARGET_FMT_lx
> -                          " => " HWADDR_FMT_plx
> -                          " %d %d\n", __func__, address, ctx->raddr, ctx->prot,
> -                          ret);
> -            return 0;
> -        }
>      }
> -    qemu_log_mask(CPU_LOG_MMU, "%s: access refused " TARGET_FMT_lx
> -                  " => " HWADDR_FMT_plx " %d %d\n",
> -                  __func__, address, raddr, ctx->prot, ret);
> +    qemu_log_mask(CPU_LOG_MMU, "%s: access %s " TARGET_FMT_lx " => "
> +                  HWADDR_FMT_plx " %d %d\n",  __func__,
> +                  ret < 0 ? "refused" : "granted", address,
> +                  ret < 0 ? 0 : *raddr, *prot, ret);
>  
>      return ret;
>  }
> @@ -1171,7 +1164,8 @@ int get_physical_address_wtlb(CPUPPCState *env, mmu_ctx_t *ctx,
>      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, eaddr, access_type);
> +        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");