s390/zcrypt: Fix blocking queue device after unbind/bind.

When the association between a queue device and the
driver is released via unbind and later re-associated
the queue device was not operational any more. Reason
was a wrong administration of the card/queue lists
within the ap device driver.

This patch introduces revised card/queue list handling
within the ap device driver: when an ap device is
detected it is initial not added to the card/queue list
any more. With driver probe the card device is added to
the card list/the queue device is added to the queue list
within a card. With driver remove the device is removed
from the card/queue list. Additionally there are some
situations within the ap device live where the lists
need update upon card/queue device release (for example
device hot unplug or suspend/resume).

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 9be4596..ea09991 100644 (file)
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -668,10 +668,28 @@ static int ap_device_probe(struct device *dev)
        struct ap_driver *ap_drv = to_ap_drv(dev->driver);
        int rc;
 
+       /* Add queue/card to list of active queues/cards */
+       spin_lock_bh(&ap_list_lock);
+       if (is_card_dev(dev))
+               list_add(&to_ap_card(dev)->list, &ap_card_list);
+       else
+               list_add(&to_ap_queue(dev)->list,
+                        &to_ap_queue(dev)->card->queues);
+       spin_unlock_bh(&ap_list_lock);
+
        ap_dev->drv = ap_drv;
        rc = ap_drv->probe ? ap_drv->probe(ap_dev) : -ENODEV;
-       if (rc)
+
+       if (rc) {
+               spin_lock_bh(&ap_list_lock);
+               if (is_card_dev(dev))
+                       list_del_init(&to_ap_card(dev)->list);
+               else
+                       list_del_init(&to_ap_queue(dev)->list);
+               spin_unlock_bh(&ap_list_lock);
                ap_dev->drv = NULL;
+       }
+
        return rc;
 }
 
@@ -680,14 +698,17 @@ static int ap_device_remove(struct device *dev)
        struct ap_device *ap_dev = to_ap_dev(dev);
        struct ap_driver *ap_drv = ap_dev->drv;
 
+       if (ap_drv->remove)
+               ap_drv->remove(ap_dev);
+
+       /* Remove queue/card from list of active queues/cards */
        spin_lock_bh(&ap_list_lock);
        if (is_card_dev(dev))
                list_del_init(&to_ap_card(dev)->list);
        else
                list_del_init(&to_ap_queue(dev)->list);
        spin_unlock_bh(&ap_list_lock);
-       if (ap_drv->remove)
-               ap_drv->remove(ap_dev);
+
        return 0;
 }
 
@@ -1056,10 +1077,6 @@ static void ap_scan_bus(struct work_struct *unused)
                                }
                                /* get it and thus adjust reference counter */
                                get_device(&ac->ap_dev.device);
-                               /* Add card device to card list */
-                               spin_lock_bh(&ap_list_lock);
-                               list_add(&ac->list, &ap_card_list);
-                               spin_unlock_bh(&ap_list_lock);
                        }
                        /* now create the new queue device */
                        aq = ap_queue_create(qid, type);
@@ -1070,10 +1087,6 @@ static void ap_scan_bus(struct work_struct *unused)
                        aq->ap_dev.device.parent = &ac->ap_dev.device;
                        dev_set_name(&aq->ap_dev.device,
                                     "%02x.%04x", id, dom);
-                       /* Add queue device to card queue list */
-                       spin_lock_bh(&ap_list_lock);
-                       list_add(&aq->list, &ac->queues);
-                       spin_unlock_bh(&ap_list_lock);
                        /* Start with a device reset */
                        spin_lock_bh(&aq->lock);
                        ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
@@ -1081,9 +1094,6 @@ static void ap_scan_bus(struct work_struct *unused)
                        /* Register device */
                        rc = device_register(&aq->ap_dev.device);
                        if (rc) {
-                               spin_lock_bh(&ap_list_lock);
-                               list_del_init(&aq->list);
-                               spin_unlock_bh(&ap_list_lock);
                                put_device(&aq->ap_dev.device);
                                continue;
                        }

diff --git a/drivers/s390/crypto/ap_card.c b/drivers/s390/crypto/ap_card.c
index cfa161c..836efac 100644 (file)
--- a/drivers/s390/crypto/ap_card.c
+++ b/drivers/s390/crypto/ap_card.c
@@ -160,7 +160,14 @@ static struct device_type ap_card_type = {
 
 static void ap_card_device_release(struct device *dev)
 {
-       kfree(to_ap_card(dev));
+       struct ap_card *ac = to_ap_card(dev);
+
+       if (!list_empty(&ac->list)) {
+               spin_lock_bh(&ap_list_lock);
+               list_del_init(&ac->list);
+               spin_unlock_bh(&ap_list_lock);
+       }
+       kfree(ac);
 }
 
 struct ap_card *ap_card_create(int id, int queue_depth, int device_type,

diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 480c58a..0f1a5d0 100644 (file)
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -584,7 +584,14 @@ static struct device_type ap_queue_type = {
 
 static void ap_queue_device_release(struct device *dev)
 {
-       kfree(to_ap_queue(dev));
+       struct ap_queue *aq = to_ap_queue(dev);
+
+       if (!list_empty(&aq->list)) {
+               spin_lock_bh(&ap_list_lock);
+               list_del_init(&aq->list);
+               spin_unlock_bh(&ap_list_lock);
+       }
+       kfree(aq);
 }
 
 struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type)