Re: [PATCH v1 37/59] s390x/event-facility.c: remove unneeded labels

[Cornelia Huck]

On Mon,  6 Jan 2020 15:24:03 -0300
Daniel Henrique Barboza <address@hidden> wrote:

> 'out' label from write_event_mask(), handle_sccb_read_events()
> and write_event_data() can be replaced by 'return'.
> 
> CC: Cornelia Huck <address@hidden>
> CC: Halil Pasic <address@hidden>
> CC: Christian Borntraeger <address@hidden>
> Signed-off-by: Daniel Henrique Barboza <address@hidden>
> ---
>  hw/s390x/event-facility.c | 21 ++++++---------------
>  1 file changed, 6 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> index 6afe278cad..f3b9661f32 100644
> --- a/hw/s390x/event-facility.c
> +++ b/hw/s390x/event-facility.c
> @@ -182,11 +182,11 @@ static void write_event_data(SCLPEventFacility *ef, 
> SCCB *sccb)
>  {
>      if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
>          sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
> -        goto out;
> +        return;
>      }
>      if (be16_to_cpu(sccb->h.length) < 8) {
>          sccb->h.response_code = 
> cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
> -        goto out;
> +        return;
>      }
>      /* first do a sanity check of the write events */
>      sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
> @@ -196,9 +196,6 @@ static void write_event_data(SCLPEventFacility *ef, SCCB 
> *sccb)
>          sccb->h.response_code =
>                  cpu_to_be16(handle_sccb_write_events(ef, sccb));
>      }
> -
> -out:
> -    return;
>  }

I'm fine with the changes to write_event_data().

>  
>  static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
> @@ -262,7 +259,7 @@ static void read_event_data(SCLPEventFacility *ef, SCCB 
> *sccb)
>  
>      if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
>          sccb->h.response_code = 
> cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
> -        goto out;
> +        return;
>      }
>  
>      sclp_cp_receive_mask = ef->receive_mask;
> @@ -280,18 +277,15 @@ static void read_event_data(SCLPEventFacility *ef, SCCB 
> *sccb)
>              (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
>              sccb->h.response_code =
>                      cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
> -            goto out;
> +            return;
>          }
>          break;
>      default:
>          sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
> -        goto out;
> +        return;
>      }
>      sccb->h.response_code = cpu_to_be16(
>              handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
> -
> -out:
> -    return;
>  }

I think read_event_data() is still a bit confusing, even if we get rid
of the 'out:' label, as the flow remains the same. How about something
like the following, which makes it clear that we handle the sccb events
for unconditional read and for a selective read with a valid mask:

diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index 6afe278cad15..877721d6601e 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -262,17 +262,17 @@ static void read_event_data(SCLPEventFacility *ef, SCCB 
*sccb)
 
     if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
-        goto out;
+        return;
     }
 
-    sclp_cp_receive_mask = ef->receive_mask;
-
-    /* get active selection mask */
     switch (sccb->h.function_code) {
     case SCLP_UNCONDITIONAL_READ:
-        sclp_active_selection_mask = sclp_cp_receive_mask;
+        sccb->h.response_code = cpu_to_be16(
+            handle_sccb_read_events(ef, sccb, ef->receive_mask));
         break;
     case SCLP_SELECTIVE_READ:
+        sclp_cp_receive_mask = ef->receive_mask;
+        /* get active selection mask */
         copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t 
*)&red->mask,
                   sizeof(sclp_active_selection_mask), ef->mask_length);
         sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask);
@@ -280,18 +280,14 @@ static void read_event_data(SCLPEventFacility *ef, SCCB 
*sccb)
             (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
             sccb->h.response_code =
                     cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
-            goto out;
+        } else {
+            sccb->h.response_code = cpu_to_be16(
+                handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
         }
         break;
     default:
         sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
-        goto out;
     }
-    sccb->h.response_code = cpu_to_be16(
-            handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
-
-out:
-    return;
 }
 
 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)


>  
>  static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
> @@ -303,7 +297,7 @@ static void write_event_mask(SCLPEventFacility *ef, SCCB 
> *sccb)
>      if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) ||
>          ((mask_length != 4) && !ef->allow_all_mask_sizes)) {
>          sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
> -        goto out;
> +        return;
>      }
>  
>      /*
> @@ -328,9 +322,6 @@ static void write_event_mask(SCLPEventFacility *ef, SCCB 
> *sccb)
>  
>      sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
>      ef->mask_length = mask_length;
> -
> -out:
> -    return;
>  }
>  
>  /* qemu object creation and initialization functions */

The changes to write_event_mask() look fine to me as well.