patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / drivers / s390 / cio / css.c

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index ffad520..f996528 100644 (file)
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -1,7 +1,7 @@
 /*
  *  drivers/s390/cio/css.c
  *  driver for channel subsystem
- *   $Revision: 1.73 $
+ *   $Revision: 1.77 $
  *
  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
  *                      IBM Corporation
@@ -166,10 +166,12 @@ css_get_subchannel_status(struct subchannel *sch, int schid)
        if (sch && sch->schib.pmcw.dnv &&
            (schib.pmcw.dev != sch->schib.pmcw.dev))
                return CIO_REVALIDATE;
+       if (sch && !sch->lpm)
+               return CIO_NO_PATH;
        return CIO_OPER;
 }
        
-static inline int
+static int
 css_evaluate_subchannel(int irq, int slow)
 {
        int event, ret, disc;
@@ -188,7 +190,11 @@ css_evaluate_subchannel(int irq, int slow)
                return -EAGAIN; /* Will be done on the slow path. */
        }
        event = css_get_subchannel_status(sch, irq);
+       CIO_MSG_EVENT(4, "Evaluating schid %04x, event %d, %s, %s path.\n",
+                     irq, event, sch?(disc?"disconnected":"normal"):"unknown",
+                     slow?"slow":"fast");
        switch (event) {
+       case CIO_NO_PATH:
        case CIO_GONE:
                if (!sch) {
                        /* Never used this subchannel. Ignore. */
@@ -196,7 +202,8 @@ css_evaluate_subchannel(int irq, int slow)
                        break;
                }
                if (sch->driver && sch->driver->notify &&
-                   sch->driver->notify(&sch->dev, CIO_GONE)) {
+                   sch->driver->notify(&sch->dev, event)) {
+                       cio_disable_subchannel(sch);
                        device_set_disconnected(sch);
                        ret = 0;
                        break;
@@ -205,6 +212,7 @@ css_evaluate_subchannel(int irq, int slow)
                 * Unregister subchannel.
                 * The device will be killed automatically.
                 */
+               cio_disable_subchannel(sch);
                device_unregister(&sch->dev);
                /* Reset intparm to zeroes. */
                sch->schib.pmcw.intparm = 0;
@@ -218,12 +226,21 @@ css_evaluate_subchannel(int irq, int slow)
                 * We don't notify the driver since we have to throw the device
                 * away in any case.
                 */
-               device_unregister(&sch->dev);
-               /* Reset intparm to zeroes. */
-               sch->schib.pmcw.intparm = 0;
-               cio_modify(sch);
-               put_device(&sch->dev);
-               ret = css_probe_device(irq);
+               if (!disc) {
+                       device_unregister(&sch->dev);
+                       /* Reset intparm to zeroes. */
+                       sch->schib.pmcw.intparm = 0;
+                       cio_modify(sch);
+                       put_device(&sch->dev);
+                       ret = css_probe_device(irq);
+               } else {
+                       /*
+                        * We can't immediately deregister the disconnected
+                        * device since it might block.
+                        */
+                       device_trigger_reprobe(sch);
+                       ret = 0;
+               }
                break;
        case CIO_OPER:
                if (disc)
@@ -257,23 +274,44 @@ css_rescan_devices(void)
        }
 }
 
-static void
-css_evaluate_slow_subchannel(unsigned long schid)
-{
-       css_evaluate_subchannel(schid, 1);
-}
+struct slow_subchannel {
+       struct list_head slow_list;
+       unsigned long schid;
+};
 
-void
+static LIST_HEAD(slow_subchannels_head);
+static spinlock_t slow_subchannel_lock = SPIN_LOCK_UNLOCKED;
+
+static void
 css_trigger_slow_path(void)
 {
+       CIO_TRACE_EVENT(4, "slowpath");
+
        if (need_rescan) {
                need_rescan = 0;
                css_rescan_devices();
                return;
        }
-       css_walk_subchannel_slow_list(css_evaluate_slow_subchannel);
+
+       spin_lock_irq(&slow_subchannel_lock);
+       while (!list_empty(&slow_subchannels_head)) {
+               struct slow_subchannel *slow_sch =
+                       list_entry(slow_subchannels_head.next,
+                                  struct slow_subchannel, slow_list);
+
+               list_del_init(slow_subchannels_head.next);
+               spin_unlock_irq(&slow_subchannel_lock);
+               css_evaluate_subchannel(slow_sch->schid, 1);
+               spin_lock_irq(&slow_subchannel_lock);
+               kfree(slow_sch);
+       }
+       spin_unlock_irq(&slow_subchannel_lock);
 }
 
+typedef void (*workfunc)(void *);
+DECLARE_WORK(slow_path_work, (workfunc)css_trigger_slow_path, NULL);
+struct workqueue_struct *slow_path_wq;
+
 /*
  * Rescan for new devices. FIXME: This is slow.
  * This function is called when we have lost CRWs due to overflows and we have
@@ -434,14 +472,6 @@ s390_root_dev_unregister(struct device *dev)
                device_unregister(dev);
 }
 
-struct slow_subchannel {
-       struct list_head slow_list;
-       unsigned long schid;
-};
-
-static LIST_HEAD(slow_subchannels_head);
-static spinlock_t slow_subchannel_lock = SPIN_LOCK_UNLOCKED;
-
 int
 css_enqueue_subchannel_slow(unsigned long schid)
 {
@@ -475,25 +505,7 @@ css_clear_subchannel_slow_list(void)
        spin_unlock_irqrestore(&slow_subchannel_lock, flags);
 }
 
-void
-css_walk_subchannel_slow_list(void (*fn)(unsigned long))
-{
-       unsigned long flags;
-
-       spin_lock_irqsave(&slow_subchannel_lock, flags);
-       while (!list_empty(&slow_subchannels_head)) {
-               struct slow_subchannel *slow_sch =
-                       list_entry(slow_subchannels_head.next,
-                                  struct slow_subchannel, slow_list);
 
-               list_del_init(slow_subchannels_head.next);
-               spin_unlock_irqrestore(&slow_subchannel_lock, flags);
-               fn(slow_sch->schid);
-               spin_lock_irqsave(&slow_subchannel_lock, flags);
-               kfree(slow_sch);
-       }
-       spin_unlock_irqrestore(&slow_subchannel_lock, flags);
-}
 
 int
 css_slow_subchannels_exist(void)