Bugfixes for s390x: set subsystem id in the lowcore when booting from the

s390-ccw bios, and set the channel-program address after I/O completion,
 when applicable.
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Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20140708' into staging

Bugfixes for s390x: set subsystem id in the lowcore when booting from the
s390-ccw bios, and set the channel-program address after I/O completion,
when applicable.

# gpg: Signature made Tue 08 Jul 2014 14:18:20 BST using RSA key ID C6F02FAF
# gpg: Can't check signature: public key not found

* remotes/cohuck/tags/s390x-20140708:
  s390x/css: reflect cpa in scsw
  pc-bios/s390-ccw: update binary
  pc-bios/s390-ccw: store proper subsystem information word

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/s390x/css.c

@@ -200,6 +200,7 @@ static void sch_handle_halt_func(SubchDev *sch)
 
     PMCW *p = &sch->curr_status.pmcw;
     SCSW *s = &sch->curr_status.scsw;
+    hwaddr curr_ccw = sch->channel_prog;
     int path;
 
     /* Path management: In our simple css, we always choose the only path. */
@@ -216,6 +217,10 @@ static void sch_handle_halt_func(SubchDev *sch)
           (s->ctrl & SCSW_ACTL_SUSP))) {
         s->dstat = SCSW_DSTAT_DEVICE_END;
     }
+    if ((s->ctrl & (SCSW_ACTL_SUBCH_ACTIVE | SCSW_ACTL_DEVICE_ACTIVE)) ||
+        (s->ctrl & SCSW_ACTL_SUSP)) {
+        s->cpa = curr_ccw + 8;
+    }
     s->cstat = 0;
     p->lpum = path;
 
@@ -398,6 +403,7 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
                     SCSW_STCTL_STATUS_PEND;
             s->dstat = SCSW_DSTAT_CHANNEL_END | SCSW_DSTAT_DEVICE_END;
+            s->cpa = sch->channel_prog + 8;
             break;
         case -ENOSYS:
             /* unsupported command, generate unit check (command reject) */
@@ -408,6 +414,7 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
+            s->cpa = sch->channel_prog + 8;
             break;
         case -EFAULT:
             /* memory problem, generate channel data check */
@@ -416,6 +423,7 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
+            s->cpa = sch->channel_prog + 8;
             break;
         case -EBUSY:
             /* subchannel busy, generate deferred cc 1 */
@@ -436,6 +444,7 @@ static void sch_handle_start_func(SubchDev *sch, ORB *orb)
             s->ctrl &= ~SCSW_CTRL_MASK_STCTL;
             s->ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
                     SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
+            s->cpa = sch->channel_prog + 8;
             break;
         }
     } while (ret == -EAGAIN);

pc-bios/s390-ccw/bootmap.c

@@ -51,6 +51,8 @@ static void jump_to_IPL_2(void)
 
 static void jump_to_IPL_code(uint64_t address)
 {
+    /* store the subsystem information _after_ the bootmap was loaded */
+    write_subsystem_identification();
     /*
      * The IPL PSW is at address 0. We also must not overwrite the
      * content of non-BIOS memory after we loaded the guest, so we

pc-bios/s390-ccw/main.c

@@ -13,6 +13,22 @@
 
 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
 uint64_t boot_value;
+struct subchannel_id blk_schid = { .one = 1 };
+
+/*
+ * Priniciples of Operations (SA22-7832-09) chapter 17 requires that
+ * a subsystem-identification is at 184-187 and bytes 188-191 are zero
+ * after list-directed-IPL and ccw-IPL.
+ */
+void write_subsystem_identification(void)
+{
+    struct subchannel_id *schid = (struct subchannel_id *) 184;
+    uint32_t *zeroes = (uint32_t *) 188;
+
+    *schid = blk_schid;
+    *zeroes = 0;
+}
+
 
 void virtio_panic(const char *string)
 {
@@ -23,7 +39,6 @@ void virtio_panic(const char *string)
 
 static void virtio_setup(uint64_t dev_info)
 {
-    struct subchannel_id blk_schid = { .one = 1 };
     struct schib schib;
     int i;
     int r;

pc-bios/s390-ccw/s390-ccw.h

@@ -50,6 +50,7 @@ void disabled_wait(void);
 
 /* main.c */
 void virtio_panic(const char *string);
+void write_subsystem_identification(void);
 
 /* sclp-ascii.c */
 void sclp_print(const char *string);