s390/qeth: unbreak OSM and OSN support

commit b4d72c08b358 ("qeth: bridgeport support - basic control")
broke the support for OSM and OSN devices as follows:

As OSM and OSN are L2 only, qeth_core_probe_device() does an early
setup by loading the l2 discipline and calling qeth_l2_probe_device().
In this context, adding the l2-specific bridgeport sysfs attributes
via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c,
since the basic sysfs infrastructure for the device hasn't been
established yet.

Note that OSN actually has its own unique sysfs attributes
(qeth_osn_devtype), so the additional attributes shouldn't be created
at all.
For OSM, add a new qeth_l2_devtype that contains all the common
and l2-specific sysfs attributes.
When qeth_core_probe_device() does early setup for OSM or OSN, assign
the corresponding devtype so that the ccwgroup probe code creates the
full set of sysfs attributes.
This allows us to skip qeth_l2_create_device_attributes() in case
of an early setup.

Any device that can't do early setup will initially have only the
generic sysfs attributes, and when it's probed later
qeth_l2_probe_device() adds the l2-specific attributes.

If an early-setup device is removed (by calling ccwgroup_ungroup()),
device_unregister() will - using the devtype - delete the
l2-specific attributes before qeth_l2_remove_device() is called.
So make sure to not remove them twice.

What complicates the issue is that qeth_l2_probe_device() and
qeth_l2_remove_device() is also called on a device when its
layer2 attribute changes (ie. its layer mode is switched).
For early-setup devices this wouldn't work properly - we wouldn't
remove the l2-specific attributes when switching to L3.
But switching the layer mode doesn't actually make any sense;
we already decided that the device can only operate in L2!
So just refuse to switch the layer mode on such devices. Note that
OSN doesn't have a layer2 attribute, so we only need to special-case
OSM.

Based on an initial patch by Ursula Braun.

Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index f6aa21176d89780e9e745f9045255ff37f1cf788..30bc6105aac3731f2bfad5ffd0d4f14f07f9d291 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -701,6 +701,7 @@ enum qeth_discipline_id {
 };
 
 struct qeth_discipline {
+       const struct device_type *devtype;
        void (*start_poll)(struct ccw_device *, int, unsigned long);
        qdio_handler_t *input_handler;
        qdio_handler_t *output_handler;
@@ -875,6 +876,9 @@ extern struct qeth_discipline qeth_l2_discipline;
 extern struct qeth_discipline qeth_l3_discipline;
 extern const struct attribute_group *qeth_generic_attr_groups[];
 extern const struct attribute_group *qeth_osn_attr_groups[];
+extern const struct attribute_group qeth_device_attr_group;
+extern const struct attribute_group qeth_device_blkt_group;
+extern const struct device_type qeth_generic_devtype;
 extern struct workqueue_struct *qeth_wq;
 
 int qeth_card_hw_is_reachable(struct qeth_card *);

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 5bfd7c15d6a9d83d5ee7442003c3f969f2febd1b..fc6d85f2b38d60d4c1b62bd169776d5cfcabcc52 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5530,10 +5530,12 @@ void qeth_core_free_discipline(struct qeth_card *card)
        card->discipline = NULL;
 }
 
-static const struct device_type qeth_generic_devtype = {
+const struct device_type qeth_generic_devtype = {
        .name = "qeth_generic",
        .groups = qeth_generic_attr_groups,
 };
+EXPORT_SYMBOL_GPL(qeth_generic_devtype);
+
 static const struct device_type qeth_osn_devtype = {
        .name = "qeth_osn",
        .groups = qeth_osn_attr_groups,
@@ -5659,23 +5661,22 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
                goto err_card;
        }
 
-       if (card->info.type == QETH_CARD_TYPE_OSN)
-               gdev->dev.type = &qeth_osn_devtype;
-       else
-               gdev->dev.type = &qeth_generic_devtype;
-
        switch (card->info.type) {
        case QETH_CARD_TYPE_OSN:
        case QETH_CARD_TYPE_OSM:
                rc = qeth_core_load_discipline(card, QETH_DISCIPLINE_LAYER2);
                if (rc)
                        goto err_card;
+
+               gdev->dev.type = (card->info.type != QETH_CARD_TYPE_OSN)
+                                       ? card->discipline->devtype
+                                       : &qeth_osn_devtype;
                rc = card->discipline->setup(card->gdev);
                if (rc)
                        goto err_disc;
-       case QETH_CARD_TYPE_OSD:
-       case QETH_CARD_TYPE_OSX:
+               break;
        default:
+               gdev->dev.type = &qeth_generic_devtype;
                break;
        }
 

diff --git a/drivers/s390/net/qeth_core_sys.c b/drivers/s390/net/qeth_core_sys.c
index 412ff61891ac0820d36650b232f4d80c97bdd8e7..db6a285d41e033674706543c2353c0312046e331 100644 (file)
--- a/drivers/s390/net/qeth_core_sys.c
+++ b/drivers/s390/net/qeth_core_sys.c
@@ -413,12 +413,16 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 
        if (card->options.layer2 == newdis)
                goto out;
-       else {
-               card->info.mac_bits  = 0;
-               if (card->discipline) {
-                       card->discipline->remove(card->gdev);
-                       qeth_core_free_discipline(card);
-               }
+       if (card->info.type == QETH_CARD_TYPE_OSM) {
+               /* fixed layer, can't switch */
+               rc = -EOPNOTSUPP;
+               goto out;
+       }
+
+       card->info.mac_bits = 0;
+       if (card->discipline) {
+               card->discipline->remove(card->gdev);
+               qeth_core_free_discipline(card);
        }
 
        rc = qeth_core_load_discipline(card, newdis);
@@ -705,10 +709,11 @@ static struct attribute *qeth_blkt_device_attrs[] = {
        &dev_attr_inter_jumbo.attr,
        NULL,
 };
-static struct attribute_group qeth_device_blkt_group = {
+const struct attribute_group qeth_device_blkt_group = {
        .name = "blkt",
        .attrs = qeth_blkt_device_attrs,
 };
+EXPORT_SYMBOL_GPL(qeth_device_blkt_group);
 
 static struct attribute *qeth_device_attrs[] = {
        &dev_attr_state.attr,
@@ -728,9 +733,10 @@ static struct attribute *qeth_device_attrs[] = {
        &dev_attr_switch_attrs.attr,
        NULL,
 };
-static struct attribute_group qeth_device_attr_group = {
+const struct attribute_group qeth_device_attr_group = {
        .attrs = qeth_device_attrs,
 };
+EXPORT_SYMBOL_GPL(qeth_device_attr_group);
 
 const struct attribute_group *qeth_generic_attr_groups[] = {
        &qeth_device_attr_group,

diff --git a/drivers/s390/net/qeth_l2.h b/drivers/s390/net/qeth_l2.h
index 29d9fb3890ad570826db6d54b1396c149f83fcb5..0d59f9a45ea9e3c52ba4eee9cbc7b37b433dd449 100644 (file)
--- a/drivers/s390/net/qeth_l2.h
+++ b/drivers/s390/net/qeth_l2.h
@@ -8,6 +8,8 @@
 
 #include "qeth_core.h"
 
+extern const struct attribute_group *qeth_l2_attr_groups[];
+
 int qeth_l2_create_device_attributes(struct device *);
 void qeth_l2_remove_device_attributes(struct device *);
 void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card);

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 2d2623182abf88fd19625b09348a3d06a28f4e98..04666fe231aa8363ee38891ae675e0ee1fd49ce0 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -880,14 +880,21 @@ static int qeth_l2_stop(struct net_device *dev)
        return 0;
 }
 
+static const struct device_type qeth_l2_devtype = {
+       .name = "qeth_layer2",
+       .groups = qeth_l2_attr_groups,
+};
+
 static int qeth_l2_probe_device(struct ccwgroup_device *gdev)
 {
        struct qeth_card *card = dev_get_drvdata(&gdev->dev);
        int rc;
 
-       rc = qeth_l2_create_device_attributes(&gdev->dev);
-       if (rc)
-               return rc;
+       if (gdev->dev.type == &qeth_generic_devtype) {
+               rc = qeth_l2_create_device_attributes(&gdev->dev);
+               if (rc)
+                       return rc;
+       }
        INIT_LIST_HEAD(&card->vid_list);
        hash_init(card->mac_htable);
        card->options.layer2 = 1;
@@ -899,7 +906,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *cgdev)
 {
        struct qeth_card *card = dev_get_drvdata(&cgdev->dev);
 
-       qeth_l2_remove_device_attributes(&cgdev->dev);
+       if (cgdev->dev.type == &qeth_generic_devtype)
+               qeth_l2_remove_device_attributes(&cgdev->dev);
        qeth_set_allowed_threads(card, 0, 1);
        wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0);
 
@@ -1272,6 +1280,7 @@ static int qeth_l2_control_event(struct qeth_card *card,
 }
 
 struct qeth_discipline qeth_l2_discipline = {
+       .devtype = &qeth_l2_devtype,
        .start_poll = qeth_qdio_start_poll,
        .input_handler = (qdio_handler_t *) qeth_qdio_input_handler,
        .output_handler = (qdio_handler_t *) qeth_qdio_output_handler,

diff --git a/drivers/s390/net/qeth_l2_sys.c b/drivers/s390/net/qeth_l2_sys.c
index 687972356d6b00f8776cb332e31b1ae0063183a5..9696baa49e2d4409062be4338ea383472a7d4ab0 100644 (file)
--- a/drivers/s390/net/qeth_l2_sys.c
+++ b/drivers/s390/net/qeth_l2_sys.c
@@ -269,3 +269,11 @@ void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card)
        } else
                qeth_bridgeport_an_set(card, 0);
 }
+
+const struct attribute_group *qeth_l2_attr_groups[] = {
+       &qeth_device_attr_group,
+       &qeth_device_blkt_group,
+       /* l2 specific, see l2_{create,remove}_device_attributes(): */
+       &qeth_l2_bridgeport_attr_group,
+       NULL,
+};

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index ae70daf33bd53aef3c75717b73c860bdd9e8e262..6c2146fc831aa08c9f8a42104a050ba34d7f9bd6 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -3309,6 +3309,7 @@ static int qeth_l3_control_event(struct qeth_card *card,
 }
 
 struct qeth_discipline qeth_l3_discipline = {
+       .devtype = &qeth_generic_devtype,
        .start_poll = qeth_qdio_start_poll,
        .input_handler = (qdio_handler_t *) qeth_qdio_input_handler,
        .output_handler = (qdio_handler_t *) qeth_qdio_output_handler,