Re: [PATCH 12/14] target/s390x: Simplify per_ifetch, per_check_exception

[Thomas Huth]

On 02/05/2024 07.44, Richard Henderson wrote:
> Set per_address and ilen in per_ifetch; this is valid for
> all PER exceptions and will last until the end of the
> instruction.  Therefore we don't need to give the same
> data to per_check_exception.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>
> # Conflicts:
> #       target/s390x/tcg/misc_helper.c
> ---
>   target/s390x/helper.h          |  4 ++--
>   target/s390x/tcg/misc_helper.c | 23 +++++++++--------------
>   target/s390x/tcg/translate.c   | 20 ++++++++++++--------
>   3 files changed, 23 insertions(+), 24 deletions(-)
>
> diff --git a/target/s390x/helper.h b/target/s390x/helper.h
> index 31bd193322..1a8a76abb9 100644
> --- a/target/s390x/helper.h
> +++ b/target/s390x/helper.h
> @@ -359,9 +359,9 @@ DEF_HELPER_FLAGS_4(ipte, TCG_CALL_NO_RWG, void, env, i64, 
> i64, i32)
>   DEF_HELPER_FLAGS_1(ptlb, TCG_CALL_NO_RWG, void, env)
>   DEF_HELPER_FLAGS_1(purge, TCG_CALL_NO_RWG, void, env)
>   DEF_HELPER_3(lra, i64, env, i64, i64)
> -DEF_HELPER_FLAGS_3(per_check_exception, TCG_CALL_NO_WG, void, env, i64, i32)
> +DEF_HELPER_FLAGS_1(per_check_exception, TCG_CALL_NO_WG, void, env)
>   DEF_HELPER_FLAGS_3(per_branch, TCG_CALL_NO_WG, void, env, i64, i32)
> -DEF_HELPER_FLAGS_2(per_ifetch, TCG_CALL_NO_WG, void, env, i64)
> +DEF_HELPER_FLAGS_2(per_ifetch, TCG_CALL_NO_WG, void, env, i32)
>   DEF_HELPER_FLAGS_2(per_store_real, TCG_CALL_NO_WG, noreturn, env, i32)
>   DEF_HELPER_FLAGS_1(stfl, TCG_CALL_NO_RWG, void, env)
>   
> diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
> index 5f1efc6a32..f5e674a26e 100644
> --- a/target/s390x/tcg/misc_helper.c
> +++ b/target/s390x/tcg/misc_helper.c
> @@ -604,12 +604,10 @@ G_NORETURN static void 
> per_raise_exception_log(CPUS390XState *env)
>       per_raise_exception(env);
>   }
>   
> -void HELPER(per_check_exception)(CPUS390XState *env, uint64_t next_pc,
> -                                 uint32_t ilen)
> +void HELPER(per_check_exception)(CPUS390XState *env)
>   {
> +    /* psw_addr, per_address and int_pgm_ilen are already set. */
>       if (unlikely(env->per_perc_atmid)) {
> -        env->psw.addr = next_pc;
> -        env->int_pgm_ilen = ilen;
>           per_raise_exception_log(env);
>       }
>   }
> @@ -639,23 +637,20 @@ void HELPER(per_branch)(CPUS390XState *env, uint64_t 
> dest, uint32_t ilen)
>       per_raise_exception_log(env);
>   }
>   
> -void HELPER(per_ifetch)(CPUS390XState *env, uint64_t addr)
> +void HELPER(per_ifetch)(CPUS390XState *env, uint32_t ilen)
>   {
> -    if (get_per_in_range(env, addr)) {
> -        env->per_address = addr;
> +    if (get_per_in_range(env, env->psw.addr)) {
> +        env->per_address = env->psw.addr;
> +        env->int_pgm_ilen = ilen;
>           env->per_perc_atmid = PER_CODE_EVENT_IFETCH | get_per_atmid(env);
>   
>           /* If the instruction has to be nullified, trigger the
>              exception immediately. */
>           if (env->cregs[9] & PER_CR9_EVENT_IFETCH_NULLIFICATION) {
> -            CPUState *cs = env_cpu(env);
> -
>               env->per_perc_atmid |= PER_CODE_EVENT_NULLIFICATION;
> -            env->int_pgm_code = PGM_PER;
> -            env->int_pgm_ilen = get_ilen(cpu_ldub_code(env, addr));
> -
> -            cs->exception_index = EXCP_PGM;
> -            cpu_loop_exit(cs);
> +            qemu_log_mask(CPU_LOG_INT, "PER interrupt before %#" PRIx64 "\n",
> +                          env->per_address);

FYI, checkpatch.pl complains:

ERROR: Don't use '#' flag of printf format ('%#') in format strings, use 
'0x' prefix instead
#84: FILE: target/s390x/tcg/misc_helper.c:651:
+            qemu_log_mask(CPU_LOG_INT, "PER interrupt before %#" PRIx64

I'll fix it up while picking up your patch.

 Thomas