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qeth: Make s390dbf card entries persistent
authorStefan Raspl <raspl@linux.vnet.ibm.com>
Mon, 21 Jan 2013 02:30:22 +0000 (02:30 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 21 Jan 2013 18:51:15 +0000 (13:51 -0500)
As of now, s390dbf entries for the cards are discarded as soon as the
device is removed. However, this will also bar us of all chances of
getting valuable debug information after a device has been removed.
This patch will keep the s390dbf entries around until the qeth module
is removed.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/s390/net/qeth_core_main.c

index 1cccbad..3535b13 100644 (file)
@@ -5122,13 +5122,81 @@ static const struct device_type qeth_osn_devtype = {
        .groups = qeth_osn_attr_groups,
 };
 
+#define DBF_NAME_LEN   20
+
+struct qeth_dbf_entry {
+       char dbf_name[DBF_NAME_LEN];
+       debug_info_t *dbf_info;
+       struct list_head dbf_list;
+};
+
+static LIST_HEAD(qeth_dbf_list);
+static DEFINE_MUTEX(qeth_dbf_list_mutex);
+
+static debug_info_t *qeth_get_dbf_entry(char *name)
+{
+       struct qeth_dbf_entry *entry;
+       debug_info_t *rc = NULL;
+
+       mutex_lock(&qeth_dbf_list_mutex);
+       list_for_each_entry(entry, &qeth_dbf_list, dbf_list) {
+               if (strcmp(entry->dbf_name, name) == 0) {
+                       rc = entry->dbf_info;
+                       break;
+               }
+       }
+       mutex_unlock(&qeth_dbf_list_mutex);
+       return rc;
+}
+
+static int qeth_add_dbf_entry(struct qeth_card *card, char *name)
+{
+       struct qeth_dbf_entry *new_entry;
+
+       card->debug = debug_register(name, 2, 1, 8);
+       if (!card->debug) {
+               QETH_DBF_TEXT_(SETUP, 2, "%s", "qcdbf");
+               goto err;
+       }
+       if (debug_register_view(card->debug, &debug_hex_ascii_view))
+               goto err_dbg;
+       new_entry = kzalloc(sizeof(struct qeth_dbf_entry), GFP_KERNEL);
+       if (!new_entry)
+               goto err_dbg;
+       strncpy(new_entry->dbf_name, name, DBF_NAME_LEN);
+       new_entry->dbf_info = card->debug;
+       mutex_lock(&qeth_dbf_list_mutex);
+       list_add(&new_entry->dbf_list, &qeth_dbf_list);
+       mutex_unlock(&qeth_dbf_list_mutex);
+
+       return 0;
+
+err_dbg:
+       debug_unregister(card->debug);
+err:
+       return -ENOMEM;
+}
+
+static void qeth_clear_dbf_list(void)
+{
+       struct qeth_dbf_entry *entry, *tmp;
+
+       mutex_lock(&qeth_dbf_list_mutex);
+       list_for_each_entry_safe(entry, tmp, &qeth_dbf_list, dbf_list) {
+               list_del(&entry->dbf_list);
+               debug_unregister(entry->dbf_info);
+               kfree(entry);
+       }
+       mutex_unlock(&qeth_dbf_list_mutex);
+}
+
 static int qeth_core_probe_device(struct ccwgroup_device *gdev)
 {
        struct qeth_card *card;
        struct device *dev;
        int rc;
        unsigned long flags;
-       char dbf_name[20];
+       char dbf_name[DBF_NAME_LEN];
 
        QETH_DBF_TEXT(SETUP, 2, "probedev");
 
@@ -5147,13 +5215,12 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
 
        snprintf(dbf_name, sizeof(dbf_name), "qeth_card_%s",
                dev_name(&gdev->dev));
-       card->debug = debug_register(dbf_name, 2, 1, 8);
+       card->debug = qeth_get_dbf_entry(dbf_name);
        if (!card->debug) {
-               QETH_DBF_TEXT_(SETUP, 2, "%s", "qcdbf");
-               rc = -ENOMEM;
-               goto err_card;
+               rc = qeth_add_dbf_entry(card, dbf_name);
+               if (rc)
+                       goto err_card;
        }
-       debug_register_view(card->debug, &debug_hex_ascii_view);
 
        card->read.ccwdev  = gdev->cdev[0];
        card->write.ccwdev = gdev->cdev[1];
@@ -5167,12 +5234,12 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
        rc = qeth_determine_card_type(card);
        if (rc) {
                QETH_DBF_TEXT_(SETUP, 2, "3err%d", rc);
-               goto err_dbf;
+               goto err_card;
        }
        rc = qeth_setup_card(card);
        if (rc) {
                QETH_DBF_TEXT_(SETUP, 2, "2err%d", rc);
-               goto err_dbf;
+               goto err_card;
        }
 
        if (card->info.type == QETH_CARD_TYPE_OSN)
@@ -5185,7 +5252,7 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
        case QETH_CARD_TYPE_OSM:
                rc = qeth_core_load_discipline(card, QETH_DISCIPLINE_LAYER2);
                if (rc)
-                       goto err_dbf;
+                       goto err_card;
                rc = card->discipline->setup(card->gdev);
                if (rc)
                        goto err_disc;
@@ -5204,8 +5271,6 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
 
 err_disc:
        qeth_core_free_discipline(card);
-err_dbf:
-       debug_unregister(card->debug);
 err_card:
        qeth_core_free_card(card);
 err_dev:
@@ -5225,7 +5290,6 @@ static void qeth_core_remove_device(struct ccwgroup_device *gdev)
                qeth_core_free_discipline(card);
        }
 
-       debug_unregister(card->debug);
        write_lock_irqsave(&qeth_core_card_list.rwlock, flags);
        list_del(&card->list);
        write_unlock_irqrestore(&qeth_core_card_list.rwlock, flags);
@@ -5579,6 +5643,7 @@ static int __init qeth_core_init(void)
 
        pr_info("loading core functions\n");
        INIT_LIST_HEAD(&qeth_core_card_list.list);
+       INIT_LIST_HEAD(&qeth_dbf_list);
        rwlock_init(&qeth_core_card_list.rwlock);
        mutex_init(&qeth_mod_mutex);
 
@@ -5630,6 +5695,7 @@ out_err:
 
 static void __exit qeth_core_exit(void)
 {
+       qeth_clear_dbf_list();
        destroy_workqueue(qeth_wq);
        ccwgroup_driver_unregister(&qeth_core_ccwgroup_driver);
        ccw_driver_unregister(&qeth_ccw_driver);