Re: [Qemu-devel] [PATCH v1 2/3] s390x/sclp: clean up sclp masks

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 20 Feb 2018 19:45:01 +0100
Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> wrote:

> Clean up SCLP masks: introduce an sccb_mask_t to be used for SCLP event
> masks instead of just unsigned int or uint32_t. This will allow later
> to extend the mask with more ease.

Looks mostly sane.

> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
> ---
>  hw/char/sclpconsole-lm.c          |  4 ++--
>  hw/char/sclpconsole.c             |  4 ++--
>  hw/s390x/event-facility.c         | 18 +++++++++---------
>  hw/s390x/sclpcpu.c                |  4 ++--
>  hw/s390x/sclpquiesce.c            |  4 ++--
>  include/hw/s390x/event-facility.h | 22 +++++++++++++---------
>  6 files changed, 30 insertions(+), 26 deletions(-)
> 
> diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
> index c500bda..cc4d70a 100644
> --- a/hw/char/sclpconsole-lm.c
> +++ b/hw/char/sclpconsole-lm.c

> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> index 2414614..f6f28fd 100644
> --- a/hw/s390x/event-facility.c
> +++ b/hw/s390x/event-facility.c
> @@ -30,7 +30,7 @@ struct SCLPEventFacility {
>      SysBusDevice parent_obj;
>      SCLPEventsBus sbus;
>      /* guest' receive mask */

Let's make this "guest's", as you're touching the line right below.

> -    unsigned int receive_mask;
> +    sccb_mask_t receive_mask;
>      /*
>       * when false, we keep the same broken, backwards compatible behaviour as
>       * before; when true, we implement the architecture correctly. Needed for

(...)

> @@ -241,8 +241,8 @@ static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
>  
>  static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
>  {
> -    unsigned int sclp_active_selection_mask;
> -    unsigned int sclp_cp_receive_mask;
> +    sccb_mask_t sclp_active_selection_mask = 0;

Why do you need to initialize this now?

> +    sccb_mask_t sclp_cp_receive_mask;
>  
>      ReadEventData *red = (ReadEventData *) sccb;
>  
> @@ -284,7 +284,7 @@ static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
>  {
>      WriteEventMask *we_mask = (WriteEventMask *) sccb;
>      uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
> -    uint32_t tmp_mask;
> +    sccb_mask_t tmp_mask = 0;

Same here.

>  
>      if (!mask_length || (mask_length > SCLP_EVENT_MASK_LEN_MAX) ||
>          ((mask_length != 4) && !ef->allow_all_mask_sizes)) {

(...)

> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index 5119b9b..0a8b47a 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -28,12 +28,14 @@
>  #define SCLP_EVENT_SIGNAL_QUIESCE               0x1d
>  
>  /* SCLP event masks */
> -#define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
> -#define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
> -#define SCLP_EVENT_MASK_CONFIG_MGT_DATA         0x10000000
> -#define SCLP_EVENT_MASK_OP_CMD                  0x80000000
> -#define SCLP_EVENT_MASK_MSG                     0x40000000
> -#define SCLP_EVENT_MASK_PMSGCMD                 0x00800000
> +#define SCLPEVMSK(T)  (1ULL << (sizeof(sccb_mask_t) * 8 - (T)))

SCLP_EVMASK() would be a bit more readable, I think.

> +
> +#define SCLP_EVENT_MASK_OP_CMD          SCLPEVMSK(SCLP_EVENT_OPRTNS_COMMAND)
> +#define SCLP_EVENT_MASK_MSG             SCLPEVMSK(SCLP_EVENT_MESSAGE)
> +#define SCLP_EVENT_MASK_CONFIG_MGT_DATA SCLPEVMSK(SCLP_EVENT_CONFIG_MGT_DATA)
> +#define SCLP_EVENT_MASK_PMSGCMD         SCLPEVMSK(SCLP_EVENT_PMSGCMD)
> +#define SCLP_EVENT_MASK_MSG_ASCII       SCLPEVMSK(SCLP_EVENT_ASCII_CONSOLE_DATA)
> +#define SCLP_EVENT_MASK_SIGNAL_QUIESCE  SCLPEVMSK(SCLP_EVENT_SIGNAL_QUIESCE)
>  
>  #define SCLP_UNCONDITIONAL_READ                 0x00
>  #define SCLP_SELECTIVE_READ                     0x01