On Tue, 17 Oct 2017 16:04:50 +0200
Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
> Simplify the error handling of the XSCH. 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 | 17 +++++------------
> include/hw/s390x/css.h | 2 +-
> target/s390x/ioinst.c | 23 ++++-------------------
> 3 files changed, 10 insertions(+), 32 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 ff5a05c34b..1b3be7729d 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -1402,20 +1402,17 @@ out:
> return ret;
> }
>
> -int css_do_xsch(SubchDev *sch)
> +IOInstEnding css_do_xsch(SubchDev *sch)
> {
> SCSW *s = &sch->curr_status.scsw;
> PMCW *p = &sch->curr_status.pmcw;
> - int ret;
>
> if (~(p->flags) & (PMCW_FLAGS_MASK_DNV | PMCW_FLAGS_MASK_ENA)) {
> - ret = -ENODEV;
> - goto out;
> + return IOINST_CC_NOT_OPERATIONAL;
> }
>
> if (s->ctrl & SCSW_CTRL_MASK_STCTL) {
> - ret = -EINPROGRESS;
> - goto out;
> + return IOINST_CC_STATUS_PRESENT;
> }
>
> if (!(s->ctrl & SCSW_CTRL_MASK_FCTL) ||
> @@ -1423,8 +1420,7 @@ int css_do_xsch(SubchDev *sch)
> (!(s->ctrl &
> (SCSW_ACTL_RESUME_PEND | SCSW_ACTL_START_PEND | SCSW_ACTL_SUSP)))
> ||
> (s->ctrl & SCSW_ACTL_SUBCH_ACTIVE)) {
> - ret = -EBUSY;
> - goto out;
> + return IOINST_CC_BUSY;
> }
>
> /* Cancel the current operation. */
> @@ -1436,10 +1432,7 @@ int css_do_xsch(SubchDev *sch)
> sch->last_cmd_valid = false;
> s->dstat = 0;
> s->cstat = 0;
> - ret = 0;
> -
> -out:
> - return ret;
> + return IOINST_CC_EXPECTED;
> }
>
> int css_do_csch(SubchDev *sch)
> diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
> index 10bde18452..3c319c9096 100644
> --- a/include/hw/s390x/css.h
> +++ b/include/hw/s390x/css.h
> @@ -240,7 +240,7 @@ 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);
> -int css_do_xsch(SubchDev *sch);
> +IOInstEnding css_do_xsch(SubchDev *sch);
> int css_do_csch(SubchDev *sch);
> int css_do_hsch(SubchDev *sch);
> IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb);
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index 16b5cf2fed..4ad07e9181 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -42,8 +42,6 @@ void ioinst_handle_xsch(S390CPU *cpu, uint64_t reg1)
> {
> int cssid, ssid, schid, m;
> SubchDev *sch;
> - int ret = -ENODEV;
> - int cc;
>
> if (ioinst_disassemble_sch_ident(reg1, &m, &cssid, &ssid, &schid)) {
> program_interrupt(&cpu->env, PGM_OPERAND, 4);
> @@ -51,24 +49,11 @@ void ioinst_handle_xsch(S390CPU *cpu, uint64_t reg1)
> }
> trace_ioinst_sch_id("xsch", cssid, ssid, schid);
> sch = css_find_subch(m, cssid, ssid, schid);
> - if (sch && css_subch_visible(sch)) {
> - ret = css_do_xsch(sch);
> - }
> - 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_xsch(sch));
> }
>
> void ioinst_handle_csch(S390CPU *cpu, uint64_t reg1)
