[Qemu-devel] [PATCH 6/9] s390x: refactor error handling for CSCH handler

[Halil Pasic]

Simplify the error handling of the CSCH handler avoiding arbitrary and
cryptic error codes being mapped to what a subchannel is supposed to do.
Let the code detecting the condition tell how it's to be handled in a
less ambiguous way.

Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel<pmo...@linux.vnet.ibm.com>
---
 hw/s390x/css.c         | 11 +++--------
 include/hw/s390x/css.h |  2 +-
 target/s390x/ioinst.c  | 18 +++++++++---------
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 7880c2c025..e661a87387 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -1272,15 +1272,14 @@ void css_do_xsch(SubchDev *sch)
     s->cstat = 0;
 }
 
-int css_do_csch(SubchDev *sch)
+void css_do_csch(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;
+        sch->iret.cc = 3;
+        return;
     }
 
     /* Trigger the clear function. */
@@ -1288,10 +1287,6 @@ int css_do_csch(SubchDev *sch)
     s->ctrl |= SCSW_FCTL_CLEAR_FUNC | SCSW_ACTL_CLEAR_PEND;
 
     do_subchannel_work(sch);
-    ret = 0;
-
-out:
-    return ret;
 }
 
 int css_do_hsch(SubchDev *sch)
diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
index d78ee5714b..d5a7e460ec 100644
--- a/include/hw/s390x/css.h
+++ b/include/hw/s390x/css.h
@@ -205,7 +205,7 @@ 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);
 void css_do_xsch(SubchDev *sch);
-int css_do_csch(SubchDev *sch);
+void css_do_csch(SubchDev *sch);
 int css_do_hsch(SubchDev *sch);
 void css_do_ssch(SubchDev *sch, ORB *orb);
 int css_do_tsch_get_irb(SubchDev *sch, IRB *irb, int *irb_len);
diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
index f8e038fac7..501f3135ad 100644
--- a/target/s390x/ioinst.c
+++ b/target/s390x/ioinst.c
@@ -65,8 +65,6 @@ void ioinst_handle_csch(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);
@@ -74,15 +72,17 @@ void ioinst_handle_csch(S390CPU *cpu, uint64_t reg1)
     }
     trace_ioinst_sch_id("csch", cssid, ssid, schid);
     sch = css_find_subch(m, cssid, ssid, schid);
-    if (sch && css_subch_visible(sch)) {
-        ret = css_do_csch(sch);
+    if (!sch || !css_subch_visible(sch)) {
+        setcc(cpu, 3);
+        return;
     }
-    if (ret == -ENODEV) {
-        cc = 3;
-    } else {
-        cc = 0;
+    css_subch_clear_iret(sch);
+    css_do_csch(sch);
+    if (sch->iret.pgm_chk) {
+        program_interrupt(&cpu->env, sch->iret.irq_code, 4);
+        return;
     }
-    setcc(cpu, cc);
+    setcc(cpu, sch->iret.cc);
 }
 
 void ioinst_handle_hsch(S390CPU *cpu, uint64_t reg1)
-- 
2.13.5