On Tue, 17 Oct 2017 16:04:53 +0200
Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
> Simplify the error handling of the MSCH. Let the code detecting the
> condition tell (in a less ambiguous way) how it's to be handled. No
> changes in behavior.
>
> Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com>
> ---
> hw/s390x/css.c | 18 +++++-------------
> include/hw/s390x/css.h | 2 +-
> target/s390x/ioinst.c | 23 ++++-------------------
> 3 files changed, 10 insertions(+), 33 deletions(-)
Looks sane (quoting the whole mail for the benefit of the qemu-s390x list).
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index b9e0329825..30fc236946 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -1347,28 +1347,24 @@ static void copy_schib_from_guest(SCHIB *dest, const
> SCHIB *src)
> }
> }
>
> -int css_do_msch(SubchDev *sch, const SCHIB *orig_schib)
> +IOInstEnding css_do_msch(SubchDev *sch, const SCHIB *orig_schib)
> {
> SCSW *s = &sch->curr_status.scsw;
> PMCW *p = &sch->curr_status.pmcw;
> uint16_t oldflags;
> - int ret;
> SCHIB schib;
>
> if (!(sch->curr_status.pmcw.flags & PMCW_FLAGS_MASK_DNV)) {
> - ret = 0;
> - goto out;
> + return IOINST_CC_EXPECTED;
> }
>
> if (s->ctrl & SCSW_STCTL_STATUS_PEND) {
> - ret = -EINPROGRESS;
> - goto out;
> + return IOINST_CC_STATUS_PRESENT;
> }
>
> if (s->ctrl &
> (SCSW_FCTL_START_FUNC|SCSW_FCTL_HALT_FUNC|SCSW_FCTL_CLEAR_FUNC)) {
> - ret = -EBUSY;
> - goto out;
> + return IOINST_CC_STATUS_PRESENT;
> }
>
> copy_schib_from_guest(&schib, orig_schib);
> @@ -1395,11 +1391,7 @@ int css_do_msch(SubchDev *sch, const SCHIB *orig_schib)
> && (p->flags & PMCW_FLAGS_MASK_ENA) == 0) {
> sch->disable_cb(sch);
> }
> -
> - ret = 0;
> -
> -out:
> - return ret;
> + return IOINST_CC_EXPECTED;
> }
>
> IOInstEnding css_do_xsch(SubchDev *sch)
> diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
> index 0c1efbae39..a74f6cc274 100644
> --- a/include/hw/s390x/css.h
> +++ b/include/hw/s390x/css.h
> @@ -239,7 +239,7 @@ bool css_subch_visible(SubchDev *sch);
> void css_conditional_io_interrupt(SubchDev *sch);
> int css_do_stsch(SubchDev *sch, SCHIB *schib);
> bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid);
> -int css_do_msch(SubchDev *sch, const SCHIB *schib);
> +IOInstEnding css_do_msch(SubchDev *sch, const SCHIB *schib);
> IOInstEnding css_do_xsch(SubchDev *sch);
> IOInstEnding css_do_csch(SubchDev *sch);
> IOInstEnding css_do_hsch(SubchDev *sch);
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index 8e4dacafd8..23962fbebc 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -111,8 +111,6 @@ void ioinst_handle_msch(S390CPU *cpu, uint64_t reg1,
> uint32_t ipb)
> SubchDev *sch;
> SCHIB schib;
> uint64_t addr;
> - int ret = -ENODEV;
> - int cc;
> CPUS390XState *env = &cpu->env;
> uint8_t ar;
>
> @@ -131,24 +129,11 @@ void ioinst_handle_msch(S390CPU *cpu, uint64_t reg1,
> uint32_t ipb)
> }
> trace_ioinst_sch_id("msch", cssid, ssid, schid);
> sch = css_find_subch(m, cssid, ssid, schid);
> - if (sch && css_subch_visible(sch)) {
> - ret = css_do_msch(sch, &schib);
> - }
> - switch (ret) {
> - case -ENODEV:
> - cc = 3;
> - break;
> - case -EBUSY:
> - cc = 2;
> - break;
> - case 0:
> - cc = 0;
> - break;
> - default:
> - cc = 1;
> - break;
> + if (!sch || !css_subch_visible(sch)) {
> + setcc(cpu, 3);
> + return;
> }
> - setcc(cpu, cc);
> + setcc(cpu, css_do_msch(sch, &schib));
> }
>
> static void copy_orb_from_guest(ORB *dest, const ORB *src)
