IB/cm: Add basic performance counters

Add performance/debug counters to track sent/received messages, retries,
and duplicates.  Counters are tracked per CM message type, per port.

The counters are always enabled, so intrusive state tracking is not done.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 303 insertions, 40 deletions

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 2e39236d189f..c0150147d347 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2006 Intel Corporation.  All rights reserved.
+ * Copyright (c) 2004-2007 Intel Corporation.  All rights reserved.
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -37,12 +37,14 @@
 
 #include <linux/completion.h>
 #include <linux/dma-mapping.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/idr.h>
 #include <linux/interrupt.h>
 #include <linux/random.h>
 #include <linux/rbtree.h>
 #include <linux/spinlock.h>
+#include <linux/sysfs.h>
 #include <linux/workqueue.h>
 
 #include <rdma/ib_cache.h>
@@ -78,17 +80,94 @@ static struct ib_cm {
         struct workqueue_struct *wq;
 } cm;
 
+/* Counter indexes ordered by attribute ID */
+enum {
+        CM_REQ_COUNTER,
+        CM_MRA_COUNTER,
+        CM_REJ_COUNTER,
+        CM_REP_COUNTER,
+        CM_RTU_COUNTER,
+        CM_DREQ_COUNTER,
+        CM_DREP_COUNTER,
+        CM_SIDR_REQ_COUNTER,
+        CM_SIDR_REP_COUNTER,
+        CM_LAP_COUNTER,
+        CM_APR_COUNTER,
+        CM_ATTR_COUNT,
+        CM_ATTR_ID_OFFSET = 0x0010,
+};
+
+enum {
+        CM_XMIT,
+        CM_XMIT_RETRIES,
+        CM_RECV,
+        CM_RECV_DUPLICATES,
+        CM_COUNTER_GROUPS
+};
+
+static char const counter_group_names[CM_COUNTER_GROUPS]
+                                     [sizeof("cm_rx_duplicates")] = {
+        "cm_tx_msgs", "cm_tx_retries",
+        "cm_rx_msgs", "cm_rx_duplicates"
+};
+
+struct cm_counter_group {
+        struct kobject obj;
+        atomic_long_t counter[CM_ATTR_COUNT];
+};
+
+struct cm_counter_attribute {
+        struct attribute attr;
+        int index;
+};
+
+#define CM_COUNTER_ATTR(_name, _index) \
+struct cm_counter_attribute cm_##_name##_counter_attr = { \
+        .attr = { .name = __stringify(_name), .mode = 0444, .owner = THIS_MODULE }, \
+        .index = _index \
+}
+
+static CM_COUNTER_ATTR(req, CM_REQ_COUNTER);
+static CM_COUNTER_ATTR(mra, CM_MRA_COUNTER);
+static CM_COUNTER_ATTR(rej, CM_REJ_COUNTER);
+static CM_COUNTER_ATTR(rep, CM_REP_COUNTER);
+static CM_COUNTER_ATTR(rtu, CM_RTU_COUNTER);
+static CM_COUNTER_ATTR(dreq, CM_DREQ_COUNTER);
+static CM_COUNTER_ATTR(drep, CM_DREP_COUNTER);
+static CM_COUNTER_ATTR(sidr_req, CM_SIDR_REQ_COUNTER);
+static CM_COUNTER_ATTR(sidr_rep, CM_SIDR_REP_COUNTER);
+static CM_COUNTER_ATTR(lap, CM_LAP_COUNTER);
+static CM_COUNTER_ATTR(apr, CM_APR_COUNTER);
+
+static struct attribute *cm_counter_default_attrs[] = {
+        &cm_req_counter_attr.attr,
+        &cm_mra_counter_attr.attr,
+        &cm_rej_counter_attr.attr,
+        &cm_rep_counter_attr.attr,
+        &cm_rtu_counter_attr.attr,
+        &cm_dreq_counter_attr.attr,
+        &cm_drep_counter_attr.attr,
+        &cm_sidr_req_counter_attr.attr,
+        &cm_sidr_rep_counter_attr.attr,
+        &cm_lap_counter_attr.attr,
+        &cm_apr_counter_attr.attr,
+        NULL
+};
+
 struct cm_port {
         struct cm_device *cm_dev;
         struct ib_mad_agent *mad_agent;
+        struct kobject port_obj;
         u8 port_num;
+        struct cm_counter_group counter_group[CM_COUNTER_GROUPS];
 };
 
 struct cm_device {
         struct list_head list;
         struct ib_device *device;
+        struct kobject dev_obj;
         u8 ack_delay;
-        struct cm_port port[0];
+        struct cm_port *port[0];
 };
 
 struct cm_av {
@@ -278,7 +357,7 @@ static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
         list_for_each_entry(cm_dev, &cm.device_list, list) {
                 if (!ib_find_cached_gid(cm_dev->device, &path->sgid,
                                         &p, NULL)) {
-                        port = &cm_dev->port[p-1];
+                        port = cm_dev->port[p-1];
                         break;
                 }
         }
@@ -1270,6 +1349,9 @@ static void cm_dup_req_handler(struct cm_work *work,
         struct ib_mad_send_buf *msg = NULL;
         int ret;
 
+        atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                        counter[CM_REQ_COUNTER]);
+
         /* Quick state check to discard duplicate REQs. */
         if (cm_id_priv->id.state == IB_CM_REQ_RCVD)
                 return;
@@ -1616,6 +1698,8 @@ static void cm_dup_rep_handler(struct cm_work *work)
         if (!cm_id_priv)
                 return;
 
+        atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                        counter[CM_REP_COUNTER]);
         ret = cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg);
         if (ret)
                 goto deref;
@@ -1781,6 +1865,8 @@ static int cm_rtu_handler(struct cm_work *work)
         if (cm_id_priv->id.state != IB_CM_REP_SENT &&
             cm_id_priv->id.state != IB_CM_MRA_REP_RCVD) {
                 spin_unlock_irq(&cm_id_priv->lock);
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_RTU_COUNTER]);
                 goto out;
         }
         cm_id_priv->id.state = IB_CM_ESTABLISHED;
@@ -1958,6 +2044,8 @@ static int cm_dreq_handler(struct cm_work *work)
         cm_id_priv = cm_acquire_id(dreq_msg->remote_comm_id,
                                    dreq_msg->local_comm_id);
         if (!cm_id_priv) {
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_DREQ_COUNTER]);
                 cm_issue_drep(work->port, work->mad_recv_wc);
                 return -EINVAL;
         }
@@ -1977,6 +2065,8 @@ static int cm_dreq_handler(struct cm_work *work)
         case IB_CM_MRA_REP_RCVD:
                 break;
         case IB_CM_TIMEWAIT:
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_DREQ_COUNTER]);
                 if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
                         goto unlock;
 
@@ -1988,6 +2078,10 @@ static int cm_dreq_handler(struct cm_work *work)
                 if (ib_post_send_mad(msg, NULL))
                         cm_free_msg(msg);
                 goto deref;
+        case IB_CM_DREQ_RCVD:
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_DREQ_COUNTER]);
+                goto unlock;
         default:
                 goto unlock;
         }
@@ -2339,10 +2433,20 @@ static int cm_mra_handler(struct cm_work *work)
                 if (cm_mra_get_msg_mraed(mra_msg) != CM_MSG_RESPONSE_OTHER ||
                     cm_id_priv->id.lap_state != IB_CM_LAP_SENT ||
                     ib_modify_mad(cm_id_priv->av.port->mad_agent,
-                                  cm_id_priv->msg, timeout))
+                                  cm_id_priv->msg, timeout)) {
+                        if (cm_id_priv->id.lap_state == IB_CM_MRA_LAP_RCVD)
+                                atomic_long_inc(&work->port->
+                                                counter_group[CM_RECV_DUPLICATES].
+                                                counter[CM_MRA_COUNTER]);
                         goto out;
+                }
                 cm_id_priv->id.lap_state = IB_CM_MRA_LAP_RCVD;
                 break;
+        case IB_CM_MRA_REQ_RCVD:
+        case IB_CM_MRA_REP_RCVD:
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_MRA_COUNTER]);
+                /* fall through */
         default:
                 goto out;
         }
@@ -2502,6 +2606,8 @@ static int cm_lap_handler(struct cm_work *work)
         case IB_CM_LAP_IDLE:
                 break;
         case IB_CM_MRA_LAP_SENT:
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_LAP_COUNTER]);
                 if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
                         goto unlock;
 
@@ -2515,6 +2621,10 @@ static int cm_lap_handler(struct cm_work *work)
                 if (ib_post_send_mad(msg, NULL))
                         cm_free_msg(msg);
                 goto deref;
+        case IB_CM_LAP_RCVD:
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_LAP_COUNTER]);
+                goto unlock;
         default:
                 goto unlock;
         }
@@ -2796,6 +2906,8 @@ static int cm_sidr_req_handler(struct cm_work *work)
         cur_cm_id_priv = cm_insert_remote_sidr(cm_id_priv);
         if (cur_cm_id_priv) {
                 spin_unlock_irq(&cm.lock);
+                atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
+                                counter[CM_SIDR_REQ_COUNTER]);
                 goto out; /* Duplicate message. */
         }
         cm_id_priv->id.state = IB_CM_SIDR_REQ_RCVD;
@@ -2990,6 +3102,27 @@ static void cm_send_handler(struct ib_mad_agent *mad_agent,
                             struct ib_mad_send_wc *mad_send_wc)
 {
         struct ib_mad_send_buf *msg = mad_send_wc->send_buf;
+        struct cm_port *port;
+        u16 attr_index;
+
+        port = mad_agent->context;
+        attr_index = be16_to_cpu(((struct ib_mad_hdr *)
+                                  msg->mad)->attr_id) - CM_ATTR_ID_OFFSET;
+
+        /*
+         * If the send was in response to a received message (context[0] is not
+         * set to a cm_id), and is not a REJ, then it is a send that was
+         * manually retried.
+         */
+        if (!msg->context[0] && (attr_index != CM_REJ_COUNTER))
+                msg->retries = 1;
+
+        atomic_long_add(1 + msg->retries,
+                        &port->counter_group[CM_XMIT].counter[attr_index]);
+        if (msg->retries)
+                atomic_long_add(msg->retries,
+                                &port->counter_group[CM_XMIT_RETRIES].
+                                counter[attr_index]);
 
         switch (mad_send_wc->status) {
         case IB_WC_SUCCESS:
@@ -3148,8 +3281,10 @@ EXPORT_SYMBOL(ib_cm_notify);
 static void cm_recv_handler(struct ib_mad_agent *mad_agent,
                             struct ib_mad_recv_wc *mad_recv_wc)
 {
+        struct cm_port *port = mad_agent->context;
         struct cm_work *work;
         enum ib_cm_event_type event;
+        u16 attr_id;
         int paths = 0;
 
         switch (mad_recv_wc->recv_buf.mad->mad_hdr.attr_id) {
@@ -3194,6 +3329,10 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent,
                 return;
         }
 
+        attr_id = be16_to_cpu(mad_recv_wc->recv_buf.mad->mad_hdr.attr_id);
+        atomic_long_inc(&port->counter_group[CM_RECV].
+                        counter[attr_id - CM_ATTR_ID_OFFSET]);
+
         work = kmalloc(sizeof *work + sizeof(struct ib_sa_path_rec) * paths,
                        GFP_KERNEL);
         if (!work) {
@@ -3204,7 +3343,7 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent,
         INIT_DELAYED_WORK(&work->work, cm_work_handler);
         work->cm_event.event = event;
         work->mad_recv_wc = mad_recv_wc;
-        work->port = (struct cm_port *)mad_agent->context;
+        work->port = port;
         queue_delayed_work(cm.wq, &work->work, 0);
 }
 
@@ -3379,6 +3518,108 @@ static void cm_get_ack_delay(struct cm_device *cm_dev)
                 cm_dev->ack_delay = attr.local_ca_ack_delay;
 }
 
+static ssize_t cm_show_counter(struct kobject *obj, struct attribute *attr,
+                               char *buf)
+{
+        struct cm_counter_group *group;
+        struct cm_counter_attribute *cm_attr;
+
+        group = container_of(obj, struct cm_counter_group, obj);
+        cm_attr = container_of(attr, struct cm_counter_attribute, attr);
+
+        return sprintf(buf, "%ld\n",
+                       atomic_long_read(&group->counter[cm_attr->index]));
+}
+
+static struct sysfs_ops cm_counter_ops = {
+        .show = cm_show_counter
+};
+
+static struct kobj_type cm_counter_obj_type = {
+        .sysfs_ops = &cm_counter_ops,
+        .default_attrs = cm_counter_default_attrs
+};
+
+static void cm_release_port_obj(struct kobject *obj)
+{
+        struct cm_port *cm_port;
+
+        printk(KERN_ERR "free cm port\n");
+
+        cm_port = container_of(obj, struct cm_port, port_obj);
+        kfree(cm_port);
+}
+
+static struct kobj_type cm_port_obj_type = {
+        .release = cm_release_port_obj
+};
+
+static void cm_release_dev_obj(struct kobject *obj)
+{
+        struct cm_device *cm_dev;
+
+        printk(KERN_ERR "free cm dev\n");
+
+        cm_dev = container_of(obj, struct cm_device, dev_obj);
+        kfree(cm_dev);
+}
+
+static struct kobj_type cm_dev_obj_type = {
+        .release = cm_release_dev_obj
+};
+
+struct class cm_class = {
+        .name    = "infiniband_cm",
+};
+EXPORT_SYMBOL(cm_class);
+
+static void cm_remove_fs_obj(struct kobject *obj)
+{
+        kobject_put(obj->parent);
+        kobject_put(obj);
+}
+
+static int cm_create_port_fs(struct cm_port *port)
+{
+        int i, ret;
+
+        ret = kobject_init_and_add(&port->port_obj, &cm_port_obj_type,
+                                   kobject_get(&port->cm_dev->dev_obj),
+                                   "%d", port->port_num);
+        if (ret) {
+                kfree(port);
+                return ret;
+        }
+
+        for (i = 0; i < CM_COUNTER_GROUPS; i++) {
+                ret = kobject_init_and_add(&port->counter_group[i].obj,
+                                           &cm_counter_obj_type,
+                                           kobject_get(&port->port_obj),
+                                           "%s", counter_group_names[i]);
+                if (ret)
+                        goto error;
+        }
+
+        return 0;
+
+error:
+        while (i--)
+                cm_remove_fs_obj(&port->counter_group[i].obj);
+        cm_remove_fs_obj(&port->port_obj);
+        return ret;
+
+}
+
+static void cm_remove_port_fs(struct cm_port *port)
+{
+        int i;
+
+        for (i = 0; i < CM_COUNTER_GROUPS; i++)
+                cm_remove_fs_obj(&port->counter_group[i].obj);
+
+        cm_remove_fs_obj(&port->port_obj);
+}
+
 static void cm_add_one(struct ib_device *device)
 {
         struct cm_device *cm_dev;
@@ -3397,7 +3638,7 @@ static void cm_add_one(struct ib_device *device)
         if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
                 return;
 
-        cm_dev = kmalloc(sizeof(*cm_dev) + sizeof(*port) *
+        cm_dev = kzalloc(sizeof(*cm_dev) + sizeof(*port) *
                          device->phys_port_cnt, GFP_KERNEL);
         if (!cm_dev)
                 return;
@@ -3405,11 +3646,27 @@ static void cm_add_one(struct ib_device *device)
         cm_dev->device = device;
         cm_get_ack_delay(cm_dev);
 
+        ret = kobject_init_and_add(&cm_dev->dev_obj, &cm_dev_obj_type,
+                                   &cm_class.subsys.kobj, "%s", device->name);
+        if (ret) {
+                kfree(cm_dev);
+                return;
+        }
+
         set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
         for (i = 1; i <= device->phys_port_cnt; i++) {
-                port = &cm_dev->port[i-1];
+                port = kzalloc(sizeof *port, GFP_KERNEL);
+                if (!port)
+                        goto error1;
+
+                cm_dev->port[i-1] = port;
                 port->cm_dev = cm_dev;
                 port->port_num = i;
+
+                ret = cm_create_port_fs(port);
+                if (ret)
+                        goto error1;
+
                 port->mad_agent = ib_register_mad_agent(device, i,
                                                         IB_QPT_GSI,
                                                         &reg_req,
@@ -3418,11 +3675,11 @@ static void cm_add_one(struct ib_device *device)
                                                         cm_recv_handler,
                                                         port);
                 if (IS_ERR(port->mad_agent))
-                        goto error1;
+                        goto error2;
 
                 ret = ib_modify_port(device, i, 0, &port_modify);
                 if (ret)
-                        goto error2;
+                        goto error3;
         }
         ib_set_client_data(device, &cm_client, cm_dev);
 
@@ -3431,17 +3688,20 @@ static void cm_add_one(struct ib_device *device)
         write_unlock_irqrestore(&cm.device_lock, flags);
         return;
 
-error2:
+error3:
         ib_unregister_mad_agent(port->mad_agent);
+error2:
+        cm_remove_port_fs(port);
 error1:
         port_modify.set_port_cap_mask = 0;
         port_modify.clr_port_cap_mask = IB_PORT_CM_SUP;
         while (--i) {
-                port = &cm_dev->port[i-1];
+                port = cm_dev->port[i-1];
                 ib_modify_port(device, port->port_num, 0, &port_modify);
                 ib_unregister_mad_agent(port->mad_agent);
+                cm_remove_port_fs(port);
         }
-        kfree(cm_dev);
+        cm_remove_fs_obj(&cm_dev->dev_obj);
 }
 
 static void cm_remove_one(struct ib_device *device)
@@ -3463,11 +3723,12 @@ static void cm_remove_one(struct ib_device *device)
         write_unlock_irqrestore(&cm.device_lock, flags);
 
         for (i = 1; i <= device->phys_port_cnt; i++) {
-                port = &cm_dev->port[i-1];
+                port = cm_dev->port[i-1];
                 ib_modify_port(device, port->port_num, 0, &port_modify);
                 ib_unregister_mad_agent(port->mad_agent);
+                cm_remove_port_fs(port);
         }
-        kfree(cm_dev);
+        cm_remove_fs_obj(&cm_dev->dev_obj);
 }
 
 static int __init ib_cm_init(void)
@@ -3488,17 +3749,25 @@ static int __init ib_cm_init(void)
         idr_pre_get(&cm.local_id_table, GFP_KERNEL);
         INIT_LIST_HEAD(&cm.timewait_list);
 
-        cm.wq = create_workqueue("ib_cm");
-        if (!cm.wq)
+        ret = class_register(&cm_class);
+        if (ret)
                 return -ENOMEM;
 
+        cm.wq = create_workqueue("ib_cm");
+        if (!cm.wq) {
+                ret = -ENOMEM;
+                goto error1;
+        }
+
         ret = ib_register_client(&cm_client);
         if (ret)
-                goto error;
+                goto error2;
 
         return 0;
-error:
+error2:
         destroy_workqueue(cm.wq);
+error1:
+        class_unregister(&cm_class);
         return ret;
 }
 
@@ -3519,6 +3788,7 @@ static void __exit ib_cm_cleanup(void)
         }
 
         ib_unregister_client(&cm_client);
+        class_unregister(&cm_class);
         idr_destroy(&cm.local_id_table);
 }
 
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 424983f5b1ee..4291ab42a5b9 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -106,6 +106,9 @@ enum {
         IB_UCM_MAX_DEVICES = 32
 };
 
+/* ib_cm and ib_user_cm modules share /sys/class/infiniband_cm */
+extern struct class cm_class;
+
 #define IB_UCM_BASE_DEV MKDEV(IB_UCM_MAJOR, IB_UCM_BASE_MINOR)
 
 static void ib_ucm_add_one(struct ib_device *device);
@@ -1199,7 +1202,7 @@ static int ib_ucm_close(struct inode *inode, struct file *filp)
         return 0;
 }
 
-static void ib_ucm_release_class_dev(struct class_device *class_dev)
+static void ucm_release_class_dev(struct class_device *class_dev)
 {
         struct ib_ucm_device *dev;
 
@@ -1217,11 +1220,6 @@ static const struct file_operations ucm_fops = {
         .poll    = ib_ucm_poll,
 };
 
-static struct class ucm_class = {
-        .name    = "infiniband_cm",
-        .release = ib_ucm_release_class_dev
-};
-
 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
 {
         struct ib_ucm_device *dev;
@@ -1257,9 +1255,10 @@ static void ib_ucm_add_one(struct ib_device *device)
         if (cdev_add(&ucm_dev->dev, IB_UCM_BASE_DEV + ucm_dev->devnum, 1))
                 goto err;
 
-        ucm_dev->class_dev.class = &ucm_class;
+        ucm_dev->class_dev.class = &cm_class;
         ucm_dev->class_dev.dev = device->dma_device;
         ucm_dev->class_dev.devt = ucm_dev->dev.dev;
+        ucm_dev->class_dev.release = ucm_release_class_dev;
         snprintf(ucm_dev->class_dev.class_id, BUS_ID_SIZE, "ucm%d",
                  ucm_dev->devnum);
         if (class_device_register(&ucm_dev->class_dev))
@@ -1306,40 +1305,34 @@ static int __init ib_ucm_init(void)
                                      "infiniband_cm");
         if (ret) {
                 printk(KERN_ERR "ucm: couldn't register device number\n");
-                goto err;
+                goto error1;
         }
 
-        ret = class_register(&ucm_class);
-        if (ret) {
-                printk(KERN_ERR "ucm: couldn't create class infiniband_cm\n");
-                goto err_chrdev;
-        }
-
-        ret = class_create_file(&ucm_class, &class_attr_abi_version);
+        ret = class_create_file(&cm_class, &class_attr_abi_version);
         if (ret) {
                 printk(KERN_ERR "ucm: couldn't create abi_version attribute\n");
-                goto err_class;
+                goto error2;
         }
 
         ret = ib_register_client(&ucm_client);
         if (ret) {
                 printk(KERN_ERR "ucm: couldn't register client\n");
-                goto err_class;
+                goto error3;
         }
         return 0;
 
-err_class:
-        class_unregister(&ucm_class);
-err_chrdev:
+error3:
+        class_remove_file(&cm_class, &class_attr_abi_version);
+error2:
         unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES);
-err:
+error1:
         return ret;
 }
 
 static void __exit ib_ucm_cleanup(void)
 {
         ib_unregister_client(&ucm_client);
-        class_unregister(&ucm_class);
+        class_remove_file(&cm_class, &class_attr_abi_version);
         unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES);
         idr_destroy(&ctx_id_table);
 }