Re: [Qemu-arm] [Qemu-devel] [PATCH v1 4/4] target/arm: remove run time semihosting checks

[Richard Henderson]

On 7/3/19 5:52 PM, Alex Bennée wrote:
> Now we do all our checking and use a common EXCP_SEMIHOST for
> semihosting operations we can make helper code a lot simpler.
> 
> Signed-off-by: Alex Bennée <address@hidden>
> ---
>  target/arm/helper.c | 84 +++++++++------------------------------------
>  1 file changed, 17 insertions(+), 67 deletions(-)
> 
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index ad29dc4072..5c1f741380 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -10364,83 +10364,33 @@ static void arm_cpu_do_interrupt_aarch64(CPUState 
> *cs)
>                    new_el, env->pc, pstate_read(env));
>  }
>  
> -static inline bool check_for_semihosting(CPUState *cs)
> +/*
> + * Check whether this exception is a semihosting call; if so
> + * then handle it and return true; otherwise return false.
> + *
> + * All the permission and validity checks are done at translate time.
> + */
> +static inline bool handle_semihosting(CPUState *cs)

Drop the inline, probably.

Since you are renaming away the "check", perhaps hoist

> +    if (cs->exception_index == EXCP_SEMIHOST) {

this check to the caller, change the return to void,

> @@ -10476,7 +10426,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
>       * code that caused the exception, not the target exception level,
>       * so must be handled here.
>       */
> -    if (check_for_semihosting(cs)) {
> +    if (handle_semihosting(cs)) {
>          return;
>      }

so we get

        if (cs->exception_index == EXCP_SEMIHOST) {
            handle_semihosting(cs);
            return;
        }


r~