[S390] cio: Remove grace period for vary off chpid.

The grace period handling introduced needless complexity. It didn't
help the dasd driver (which can handle terminated I/O just well),
and it doesn't help for long running channel programs (which won't
complete during the grace period anyway). Terminating I/O using a
path that just disappeared immediately is much more consistent with
what the user expects.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

5 files changed, 14 insertions, 76 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 07c7f19339d2..eabe018d348f 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -707,8 +707,7 @@ chp_process_crw(int chpid, int on)
         return chp_add(chpid);
 }
 
-static inline int
-__check_for_io_and_kill(struct subchannel *sch, int index)
+static inline int check_for_io_on_path(struct subchannel *sch, int index)
 {
         int cc;
 
@@ -718,10 +717,8 @@ __check_for_io_and_kill(struct subchannel *sch, int index)
         cc = stsch(sch->schid, &sch->schib);
         if (cc)
                 return 0;
-        if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
-                device_set_waiting(sch);
+        if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index))
                 return 1;
-        }
         return 0;
 }
 
@@ -750,12 +747,10 @@ __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
                 } else {
                         sch->opm &= ~(0x80 >> chp);
                         sch->lpm &= ~(0x80 >> chp);
-                        /*
-                         * Give running I/O a grace period in which it
-                         * can successfully terminate, even using the
-                         * just varied off path. Then kill it.
-                         */
-                        if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
+                        if (check_for_io_on_path(sch, chp))
+                                /* Path verification is done after killing. */
+                                device_kill_io(sch);
+                        else if (!sch->lpm) {
                                 if (css_enqueue_subchannel_slow(sch->schid)) {
                                         css_clear_subchannel_slow_list();
                                         need_rescan = 1;
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 15bd1e28ed70..4c2ff8336288 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -170,7 +170,7 @@ void device_trigger_reprobe(struct subchannel *);
 
 /* Helper functions for vary on/off. */
 int device_is_online(struct subchannel *);
-void device_set_waiting(struct subchannel *);
+void device_kill_io(struct subchannel *);
 
 /* Machine check helper function. */
 void device_kill_pending_timer(struct subchannel *);
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 00be9a5b4acd..c6140cc97a80 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -21,7 +21,6 @@ enum dev_state {
         /* states to wait for i/o completion before doing something */
         DEV_STATE_CLEAR_VERIFY,
         DEV_STATE_TIMEOUT_KILL,
-        DEV_STATE_WAIT4IO,
         DEV_STATE_QUIESCE,
         /* special states for devices gone not operational */
         DEV_STATE_DISCONNECTED,
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 392eb33f3a9c..44e4a53c5981 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -59,18 +59,6 @@ device_set_disconnected(struct subchannel *sch)
         cdev->private->state = DEV_STATE_DISCONNECTED;
 }
 
-void
-device_set_waiting(struct subchannel *sch)
-{
-        struct ccw_device *cdev;
-
-        if (!sch->dev.driver_data)
-                return;
-        cdev = sch->dev.driver_data;
-        ccw_device_set_timeout(cdev, 10*HZ);
-        cdev->private->state = DEV_STATE_WAIT4IO;
-}
-
 /*
  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
  */
@@ -947,7 +935,7 @@ ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
         cdev->private->state = DEV_STATE_ONLINE;
         if (cdev->handler)
                 cdev->handler(cdev, cdev->private->intparm,
-                              ERR_PTR(-ETIMEDOUT));
+                              ERR_PTR(-EIO));
         if (!sch->lpm) {
                 PREPARE_WORK(&cdev->private->kick_work,
                              ccw_device_nopath_notify, (void *)cdev);
@@ -984,51 +972,15 @@ ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
         cdev->private->state = DEV_STATE_ONLINE;
         if (cdev->handler)
                 cdev->handler(cdev, cdev->private->intparm,
-                              ERR_PTR(-ETIMEDOUT));
+                              ERR_PTR(-EIO));
 }
 
-static void
-ccw_device_wait4io_irq(struct ccw_device *cdev, enum dev_event dev_event)
-{
-        struct irb *irb;
-        struct subchannel *sch;
-
-        irb = (struct irb *) __LC_IRB;
-        /*
-         * Accumulate status and find out if a basic sense is needed.
-         * This is fine since we have already adapted the lpm.
-         */
-        ccw_device_accumulate_irb(cdev, irb);
-        if (cdev->private->flags.dosense) {
-                if (ccw_device_do_sense(cdev, irb) == 0) {
-                        cdev->private->state = DEV_STATE_W4SENSE;
-                }
-                return;
-        }
-
-        /* Iff device is idle, reset timeout. */
-        sch = to_subchannel(cdev->dev.parent);
-        if (!stsch(sch->schid, &sch->schib))
-                if (sch->schib.scsw.actl == 0)
-                        ccw_device_set_timeout(cdev, 0);
-        /* Call the handler. */
-        ccw_device_call_handler(cdev);
-        if (!sch->lpm) {
-                PREPARE_WORK(&cdev->private->kick_work,
-                             ccw_device_nopath_notify, (void *)cdev);
-                queue_work(ccw_device_notify_work, &cdev->private->kick_work);
-        } else if (cdev->private->flags.doverify)
-                ccw_device_online_verify(cdev, 0);
-}
-
-static void
-ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
+void device_kill_io(struct subchannel *sch)
 {
         int ret;
-        struct subchannel *sch;
+        struct ccw_device *cdev;
 
-        sch = to_subchannel(cdev->dev.parent);
-        ccw_device_set_timeout(cdev, 0);
+        cdev = sch->dev.driver_data;
         ret = ccw_device_cancel_halt_clear(cdev);
         if (ret == -EBUSY) {
                 ccw_device_set_timeout(cdev, 3*HZ);
@@ -1047,12 +999,12 @@ ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
         }
         if (cdev->handler)
                 cdev->handler(cdev, cdev->private->intparm,
-                              ERR_PTR(-ETIMEDOUT));
+                              ERR_PTR(-EIO));
         if (!sch->lpm) {
                 PREPARE_WORK(&cdev->private->kick_work,
                              ccw_device_nopath_notify, (void *)cdev);
                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
-        } else if (cdev->private->flags.doverify)
+        } else
                 /* Start delayed path verification. */
                 ccw_device_online_verify(cdev, 0);
 }
@@ -1289,12 +1241,6 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
                 [DEV_EVENT_TIMEOUT]     = ccw_device_killing_timeout,
                 [DEV_EVENT_VERIFY]      = ccw_device_nop, //FIXME
         },
-        [DEV_STATE_WAIT4IO] = {
-                [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
-                [DEV_EVENT_INTERRUPT]   = ccw_device_wait4io_irq,
-                [DEV_EVENT_TIMEOUT]     = ccw_device_wait4io_timeout,
-                [DEV_EVENT_VERIFY]      = ccw_device_delay_verify,
-        },
         [DEV_STATE_QUIESCE] = {
                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
                 [DEV_EVENT_INTERRUPT]   = ccw_device_quiesce_done,
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 96219935a06a..b39c1fa48acd 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -50,7 +50,6 @@ ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
         if (cdev->private->state == DEV_STATE_NOT_OPER)
                 return -ENODEV;
         if (cdev->private->state != DEV_STATE_ONLINE &&
-            cdev->private->state != DEV_STATE_WAIT4IO &&
             cdev->private->state != DEV_STATE_W4SENSE)
                 return -EINVAL;
         sch = to_subchannel(cdev->dev.parent);
@@ -155,7 +154,6 @@ ccw_device_halt(struct ccw_device *cdev, unsigned long intparm)
         if (cdev->private->state == DEV_STATE_NOT_OPER)
                 return -ENODEV;
         if (cdev->private->state != DEV_STATE_ONLINE &&
-            cdev->private->state != DEV_STATE_WAIT4IO &&
             cdev->private->state != DEV_STATE_W4SENSE)
                 return -EINVAL;
         sch = to_subchannel(cdev->dev.parent);