[S390] dasd: fix unsolicited interrupt recognition

The dasd interrupt handler needs to distinguish solicited from
unsolicited interrupts, as unsolicited interrupts may require special
handling (e.g. summary unit checks) and solicited interrupts require
proper error recovery for the failed I/O request.
The interrupt handler needs to check several bit fields in the
interrupt response block (irb) to make this distinction.
So far our check of the status control bits has not been specific
enough, which may lead to a failed request getting just retried
instead of the necessary error recovery.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 30 insertions, 40 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index ea0e565ebc9d..50cf96389d2c 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1776,13 +1776,13 @@ static void dasd_eckd_handle_unsolicited_interrupt(struct dasd_device *device,
         }
 
         /* summary unit check */
-        if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
-            (irb->ecw[7] == 0x0D)) {
+        sense = dasd_get_sense(irb);
+        if (sense && (sense[7] == 0x0D) &&
+            (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK)) {
                 dasd_alias_handle_summary_unit_check(device, irb);
                 return;
         }
 
-        sense = dasd_get_sense(irb);
         /* service information message SIM */
         if (sense && !(sense[27] & DASD_SENSE_BIT_0) &&
             ((sense[6] & DASD_SIM_SENSE) == DASD_SIM_SENSE)) {
@@ -1791,26 +1791,15 @@ static void dasd_eckd_handle_unsolicited_interrupt(struct dasd_device *device,
                 return;
         }
 
-        if ((scsw_cc(&irb->scsw) == 1) &&
-            (scsw_fctl(&irb->scsw) & SCSW_FCTL_START_FUNC) &&
-            (scsw_actl(&irb->scsw) & SCSW_ACTL_START_PEND) &&
-            (scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND)) {
+        if ((scsw_cc(&irb->scsw) == 1) && !sense &&
+            (scsw_fctl(&irb->scsw) == SCSW_FCTL_START_FUNC) &&
+            (scsw_actl(&irb->scsw) == SCSW_ACTL_START_PEND) &&
+            (scsw_stctl(&irb->scsw) == SCSW_STCTL_STATUS_PEND)) {
                 /* fake irb do nothing, they are handled elsewhere */
                 dasd_schedule_device_bh(device);
                 return;
         }
 
-        if (!sense) {
-                /* just report other unsolicited interrupts */
-                DBF_DEV_EVENT(DBF_ERR, device, "%s",
-                            "unsolicited interrupt received");
-        } else {
-                DBF_DEV_EVENT(DBF_ERR, device, "%s",
-                            "unsolicited interrupt received "
-                            "(sense available)");
-                device->discipline->dump_sense_dbf(device, irb, "unsolicited");
-        }
-
         dasd_schedule_device_bh(device);
         return;
 };
@@ -3093,23 +3082,19 @@ dasd_eckd_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
                          char *reason)
 {
         u64 *sense;
-        u32 stat;
+        u64 *stat;
 
         sense = (u64 *) dasd_get_sense(irb);
-        stat = scsw_cstat(&irb->scsw);
-        stat <<= 8;
-        stat |= scsw_dstat(&irb->scsw);
-        stat <<= 8;
-        stat |= scsw_cc(&irb->scsw);
-
+        stat = (u64 *) &irb->scsw;
         if (sense) {
-                DBF_DEV_EVENT(DBF_EMERG, device,
-                              "%s: %s %06x %016llx %016llx %016llx %016llx",
-                              reason, scsw_is_tm(&irb->scsw) ? "t" : "c", stat,
+                DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : "
+                              "%016llx %016llx %016llx %016llx",
+                              reason, *stat, *((u32 *) (stat + 1)),
                               sense[0], sense[1], sense[2], sense[3]);
         } else {
-                DBF_DEV_EVENT(DBF_EMERG, device, "%s",
-                              "SORRY - NO VALID SENSE AVAILABLE\n");
+                DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : %s",
+                              reason, *stat, *((u32 *) (stat + 1)),
+                              "NO VALID SENSE");
         }
 }
 
@@ -3135,9 +3120,12 @@ static void dasd_eckd_dump_sense_ccw(struct dasd_device *device,
                       " I/O status report for device %s:\n",
                       dev_name(&device->cdev->dev));
         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
-                       " in req: %p CS: 0x%02X DS: 0x%02X CC: 0x%02X RC: %d\n",
-                       req, scsw_cstat(&irb->scsw), scsw_dstat(&irb->scsw),
-                       scsw_cc(&irb->scsw), req ? req->intrc : 0);
+                       " in req: %p CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X "
+                       "CS:%02X RC:%d\n",
+                       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
+                       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
+                       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
+                       req ? req->intrc : 0);
         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                        " device %s: Failing CCW: %p\n",
                        dev_name(&device->cdev->dev),
@@ -3238,11 +3226,13 @@ static void dasd_eckd_dump_sense_tcw(struct dasd_device *device,
                       " I/O status report for device %s:\n",
                       dev_name(&device->cdev->dev));
         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
-                       " in req: %p CS: 0x%02X DS: 0x%02X CC: 0x%02X RC: %d "
-                       "fcxs: 0x%02X schxs: 0x%02X\n", req,
-                       scsw_cstat(&irb->scsw), scsw_dstat(&irb->scsw),
-                       scsw_cc(&irb->scsw), req->intrc,
-                       irb->scsw.tm.fcxs, irb->scsw.tm.schxs);
+                       " in req: %p CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X "
+                       "CS:%02X fcxs:%02X schxs:%02X RC:%d\n",
+                       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
+                       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
+                       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
+                       irb->scsw.tm.fcxs, irb->scsw.tm.schxs,
+                       req ? req->intrc : 0);
         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                        " device %s: Failing TCW: %p\n",
                        dev_name(&device->cdev->dev),
@@ -3250,7 +3240,7 @@ static void dasd_eckd_dump_sense_tcw(struct dasd_device *device,
 
         tsb = NULL;
         sense = NULL;
-        if (irb->scsw.tm.tcw && (irb->scsw.tm.fcxs == 0x01))
+        if (irb->scsw.tm.tcw && (irb->scsw.tm.fcxs & 0x01))
                 tsb = tcw_get_tsb(
                         (struct tcw *)(unsigned long)irb->scsw.tm.tcw);
 
@@ -3348,7 +3338,7 @@ static void dasd_eckd_dump_sense_tcw(struct dasd_device *device,
 static void dasd_eckd_dump_sense(struct dasd_device *device,
                                  struct dasd_ccw_req *req, struct irb *irb)
 {
-        if (req && scsw_is_tm(&req->irb.scsw))
+        if (scsw_is_tm(&irb->scsw))
                 dasd_eckd_dump_sense_tcw(device, req, irb);
         else
                 dasd_eckd_dump_sense_ccw(device, req, irb);