Re: [PATCH 16/43] target/ppc/mmu_common.c: Inline and remove ppc6xx_tlb_pte_check()

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

On Mon May 27, 2024 at 9:12 AM AEST, BALATON Zoltan wrote:
> This function is only called once and we can make the caller simpler
> by inlining it.

I'm inclined to agree. Splitting into function can be nice,
but translating return values here is pretty horrible.

I think it looks right.

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

>
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  target/ppc/mmu_common.c | 71 +++++++++++++----------------------------
>  1 file changed, 22 insertions(+), 49 deletions(-)
>
> diff --git a/target/ppc/mmu_common.c b/target/ppc/mmu_common.c
> index b2993e8563..784e833ff2 100644
> --- a/target/ppc/mmu_common.c
> +++ b/target/ppc/mmu_common.c
> @@ -91,33 +91,6 @@ int ppc6xx_tlb_getnum(CPUPPCState *env, target_ulong eaddr,
>      return nr;
>  }
>  
> -static int ppc6xx_tlb_pte_check(mmu_ctx_t *ctx, target_ulong pte0,
> -                                target_ulong pte1, int pteh,
> -                                MMUAccessType access_type, bool nx)
> -{
> -    /* Check validity and table match */
> -    if (!pte_is_valid(pte0) || ((pte0 >> 6) & 1) != pteh ||
> -        (pte0 & PTE_PTEM_MASK) != ctx->ptem) {
> -        return -1;
> -    }
> -    /* all matches should have equal RPN, WIMG & PP */
> -    if (ctx->raddr != (hwaddr)-1ULL &&
> -        (ctx->raddr & PTE_CHECK_MASK) != (pte1 & PTE_CHECK_MASK)) {
> -        qemu_log_mask(CPU_LOG_MMU, "Bad RPN/WIMG/PP\n");
> -        return -3;
> -    }
> -    /* Keep the matching PTE information */
> -    ctx->raddr = pte1;
> -    ctx->prot = ppc_hash32_prot(ctx->key, pte1 & HPTE32_R_PP, nx);
> -    if (check_prot_access_type(ctx->prot, access_type)) {
> -        qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
> -        return 0;
> -    } else {
> -        qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
> -        return -2;
> -    }
> -}
> -
>  /* Software driven TLB helpers */
>  
>  static int ppc6xx_tlb_check(CPUPPCState *env,
> @@ -149,32 +122,32 @@ static int ppc6xx_tlb_check(CPUPPCState *env,
>                        tlb->EPN, eaddr, tlb->pte1,
>                        access_type == MMU_DATA_STORE ? 'S' : 'L',
>                        access_type == MMU_INST_FETCH ? 'I' : 'D');
> -        switch (ppc6xx_tlb_pte_check(ctx, tlb->pte0, tlb->pte1,
> -                                     0, access_type, nx)) {
> -        case -2:
> -            /* Access violation */
> -            ret = -2;
> -            best = nr;
> -            break;
> -        case -1: /* No match */
> -        case -3: /* TLB inconsistency */
> -        default:
> -            break;
> -        case 0:
> -            /* access granted */
> -            /*
> -             * XXX: we should go on looping to check all TLBs
> -             *      consistency but we can speed-up the whole thing as
> -             *      the result would be undefined if TLBs are not
> -             *      consistent.
> -             */
> +        /* Check validity and table match */
> +        if (!pte_is_valid(tlb->pte0) || ((tlb->pte0 >> 6) & 1) != 0 ||
> +            (tlb->pte0 & PTE_PTEM_MASK) != ctx->ptem) {
> +            continue;
> +        }
> +        /* all matches should have equal RPN, WIMG & PP */
> +        if (ctx->raddr != (hwaddr)-1ULL &&
> +            (ctx->raddr & PTE_CHECK_MASK) != (tlb->pte1 & PTE_CHECK_MASK)) {
> +            qemu_log_mask(CPU_LOG_MMU, "Bad RPN/WIMG/PP\n");
> +            /* TLB inconsistency */
> +            continue;
> +        }
> +        /* Keep the matching PTE information */
> +        best = nr;
> +        ctx->raddr = tlb->pte1;
> +        ctx->prot = ppc_hash32_prot(ctx->key, tlb->pte1 & HPTE32_R_PP, nx);
> +        if (check_prot_access_type(ctx->prot, access_type)) {
> +            qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
>              ret = 0;
> -            best = nr;
> -            goto done;
> +            break;
> +        } else {
> +            qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
> +            ret = -2;
>          }
>      }
>      if (best != -1) {
> -done:
>          qemu_log_mask(CPU_LOG_MMU, "found TLB at addr " HWADDR_FMT_plx
>                        " prot=%01x ret=%d\n",
>                        ctx->raddr & TARGET_PAGE_MASK, ctx->prot, ret);