[PATCH] IB uverbs: core implementation

Add the core of the InfiniBand userspace verbs implementation, including
creating character device nodes, dispatching requests from userspace, and
passing event notifications back up to userspace.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 698 insertions, 0 deletions

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
new file mode 100644
index 00000000000..fbbe03d8c90
--- /dev/null
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -0,0 +1,698 @@
+/*
+ * Copyright (c) 2005 Topspin Communications.  All rights reserved.
+ * Copyright (c) 2005 Cisco Systems.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * $Id: uverbs_main.c 2733 2005-06-28 19:14:34Z roland $
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+
+#include <asm/uaccess.h>
+
+#include "uverbs.h"
+
+MODULE_AUTHOR("Roland Dreier");
+MODULE_DESCRIPTION("InfiniBand userspace verbs access");
+MODULE_LICENSE("Dual BSD/GPL");
+
+#define INFINIBANDEVENTFS_MAGIC 0x49426576      /* "IBev" */
+
+enum {
+        IB_UVERBS_MAJOR       = 231,
+        IB_UVERBS_BASE_MINOR  = 192,
+        IB_UVERBS_MAX_DEVICES = 32
+};
+
+#define IB_UVERBS_BASE_DEV      MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
+
+DECLARE_MUTEX(ib_uverbs_idr_mutex);
+DEFINE_IDR(ib_uverbs_pd_idr);
+DEFINE_IDR(ib_uverbs_mr_idr);
+DEFINE_IDR(ib_uverbs_mw_idr);
+DEFINE_IDR(ib_uverbs_ah_idr);
+DEFINE_IDR(ib_uverbs_cq_idr);
+DEFINE_IDR(ib_uverbs_qp_idr);
+
+static spinlock_t map_lock;
+static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
+
+static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
+                                     const char __user *buf, int in_len,
+                                     int out_len) = {
+        [IB_USER_VERBS_CMD_QUERY_PARAMS]  = ib_uverbs_query_params,
+        [IB_USER_VERBS_CMD_GET_CONTEXT]   = ib_uverbs_get_context,
+        [IB_USER_VERBS_CMD_QUERY_DEVICE]  = ib_uverbs_query_device,
+        [IB_USER_VERBS_CMD_QUERY_PORT]    = ib_uverbs_query_port,
+        [IB_USER_VERBS_CMD_QUERY_GID]     = ib_uverbs_query_gid,
+        [IB_USER_VERBS_CMD_QUERY_PKEY]    = ib_uverbs_query_pkey,
+        [IB_USER_VERBS_CMD_ALLOC_PD]      = ib_uverbs_alloc_pd,
+        [IB_USER_VERBS_CMD_DEALLOC_PD]    = ib_uverbs_dealloc_pd,
+        [IB_USER_VERBS_CMD_REG_MR]        = ib_uverbs_reg_mr,
+        [IB_USER_VERBS_CMD_DEREG_MR]      = ib_uverbs_dereg_mr,
+        [IB_USER_VERBS_CMD_CREATE_CQ]     = ib_uverbs_create_cq,
+        [IB_USER_VERBS_CMD_DESTROY_CQ]    = ib_uverbs_destroy_cq,
+        [IB_USER_VERBS_CMD_CREATE_QP]     = ib_uverbs_create_qp,
+        [IB_USER_VERBS_CMD_MODIFY_QP]     = ib_uverbs_modify_qp,
+        [IB_USER_VERBS_CMD_DESTROY_QP]    = ib_uverbs_destroy_qp,
+        [IB_USER_VERBS_CMD_ATTACH_MCAST]  = ib_uverbs_attach_mcast,
+        [IB_USER_VERBS_CMD_DETACH_MCAST]  = ib_uverbs_detach_mcast,
+};
+
+static struct vfsmount *uverbs_event_mnt;
+
+static void ib_uverbs_add_one(struct ib_device *device);
+static void ib_uverbs_remove_one(struct ib_device *device);
+
+static int ib_dealloc_ucontext(struct ib_ucontext *context)
+{
+        struct ib_uobject *uobj, *tmp;
+
+        if (!context)
+                return 0;
+
+        down(&ib_uverbs_idr_mutex);
+
+        /* XXX Free AHs */
+
+        list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
+                struct ib_qp *qp = idr_find(&ib_uverbs_qp_idr, uobj->id);
+                idr_remove(&ib_uverbs_qp_idr, uobj->id);
+                ib_destroy_qp(qp);
+                list_del(&uobj->list);
+                kfree(uobj);
+        }
+
+        list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
+                struct ib_cq *cq = idr_find(&ib_uverbs_cq_idr, uobj->id);
+                idr_remove(&ib_uverbs_cq_idr, uobj->id);
+                ib_destroy_cq(cq);
+                list_del(&uobj->list);
+                kfree(uobj);
+        }
+
+        /* XXX Free SRQs */
+        /* XXX Free MWs */
+
+        list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
+                struct ib_mr *mr = idr_find(&ib_uverbs_mr_idr, uobj->id);
+                struct ib_umem_object *memobj;
+
+                idr_remove(&ib_uverbs_mr_idr, uobj->id);
+                ib_dereg_mr(mr);
+
+                memobj = container_of(uobj, struct ib_umem_object, uobject);
+                ib_umem_release_on_close(mr->device, &memobj->umem);
+
+                list_del(&uobj->list);
+                kfree(memobj);
+        }
+
+        list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
+                struct ib_pd *pd = idr_find(&ib_uverbs_pd_idr, uobj->id);
+                idr_remove(&ib_uverbs_pd_idr, uobj->id);
+                ib_dealloc_pd(pd);
+                list_del(&uobj->list);
+                kfree(uobj);
+        }
+
+        up(&ib_uverbs_idr_mutex);
+
+        return context->device->dealloc_ucontext(context);
+}
+
+static void ib_uverbs_release_file(struct kref *ref)
+{
+        struct ib_uverbs_file *file =
+                container_of(ref, struct ib_uverbs_file, ref);
+
+        module_put(file->device->ib_dev->owner);
+        kfree(file);
+}
+
+static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
+                                    size_t count, loff_t *pos)
+{
+        struct ib_uverbs_event_file *file = filp->private_data;
+        void *event;
+        int eventsz;
+        int ret = 0;
+
+        spin_lock_irq(&file->lock);
+
+        while (list_empty(&file->event_list) && file->fd >= 0) {
+                spin_unlock_irq(&file->lock);
+
+                if (filp->f_flags & O_NONBLOCK)
+                        return -EAGAIN;
+
+                if (wait_event_interruptible(file->poll_wait,
+                                             !list_empty(&file->event_list) ||
+                                             file->fd < 0))
+                        return -ERESTARTSYS;
+
+                spin_lock_irq(&file->lock);
+        }
+
+        if (file->fd < 0) {
+                spin_unlock_irq(&file->lock);
+                return -ENODEV;
+        }
+
+        if (file->is_async) {
+                event   = list_entry(file->event_list.next,
+                                     struct ib_uverbs_async_event, list);
+                eventsz = sizeof (struct ib_uverbs_async_event_desc);
+        } else {
+                event   = list_entry(file->event_list.next,
+                                     struct ib_uverbs_comp_event, list);
+                eventsz = sizeof (struct ib_uverbs_comp_event_desc);
+        }
+
+        if (eventsz > count) {
+                ret   = -EINVAL;
+                event = NULL;
+        } else
+                list_del(file->event_list.next);
+
+        spin_unlock_irq(&file->lock);
+
+        if (event) {
+                if (copy_to_user(buf, event, eventsz))
+                        ret = -EFAULT;
+                else
+                        ret = eventsz;
+        }
+
+        kfree(event);
+
+        return ret;
+}
+
+static unsigned int ib_uverbs_event_poll(struct file *filp,
+                                         struct poll_table_struct *wait)
+{
+        unsigned int pollflags = 0;
+        struct ib_uverbs_event_file *file = filp->private_data;
+
+        poll_wait(filp, &file->poll_wait, wait);
+
+        spin_lock_irq(&file->lock);
+        if (file->fd < 0)
+                pollflags = POLLERR;
+        else if (!list_empty(&file->event_list))
+                pollflags = POLLIN | POLLRDNORM;
+        spin_unlock_irq(&file->lock);
+
+        return pollflags;
+}
+
+static void ib_uverbs_event_release(struct ib_uverbs_event_file *file)
+{
+        struct list_head *entry, *tmp;
+
+        spin_lock_irq(&file->lock);
+        if (file->fd != -1) {
+                file->fd = -1;
+                list_for_each_safe(entry, tmp, &file->event_list)
+                        if (file->is_async)
+                                kfree(list_entry(entry, struct ib_uverbs_async_event, list));
+                        else
+                                kfree(list_entry(entry, struct ib_uverbs_comp_event, list));
+        }
+        spin_unlock_irq(&file->lock);
+}
+
+static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
+{
+        struct ib_uverbs_event_file *file = filp->private_data;
+
+        ib_uverbs_event_release(file);
+        kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
+
+        return 0;
+}
+
+static struct file_operations uverbs_event_fops = {
+        /*
+         * No .owner field since we artificially create event files,
+         * so there is no increment to the module reference count in
+         * the open path.  All event files come from a uverbs command
+         * file, which already takes a module reference, so this is OK.
+         */
+        .read    = ib_uverbs_event_read,
+        .poll    = ib_uverbs_event_poll,
+        .release = ib_uverbs_event_close
+};
+
+void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
+{
+        struct ib_uverbs_file       *file = cq_context;
+        struct ib_uverbs_comp_event *entry;
+        unsigned long                flags;
+
+        entry = kmalloc(sizeof *entry, GFP_ATOMIC);
+        if (!entry)
+                return;
+
+        entry->desc.cq_handle = cq->uobject->user_handle;
+
+        spin_lock_irqsave(&file->comp_file[0].lock, flags);
+        list_add_tail(&entry->list, &file->comp_file[0].event_list);
+        spin_unlock_irqrestore(&file->comp_file[0].lock, flags);
+
+        wake_up_interruptible(&file->comp_file[0].poll_wait);
+}
+
+static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
+                                    __u64 element, __u64 event)
+{
+        struct ib_uverbs_async_event *entry;
+        unsigned long flags;
+
+        entry = kmalloc(sizeof *entry, GFP_ATOMIC);
+        if (!entry)
+                return;
+
+        entry->desc.element    = element;
+        entry->desc.event_type = event;
+
+        spin_lock_irqsave(&file->async_file.lock, flags);
+        list_add_tail(&entry->list, &file->async_file.event_list);
+        spin_unlock_irqrestore(&file->async_file.lock, flags);
+
+        wake_up_interruptible(&file->async_file.poll_wait);
+}
+
+void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
+{
+        ib_uverbs_async_handler(context_ptr,
+                                event->element.cq->uobject->user_handle,
+                                event->event);
+}
+
+void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
+{
+        ib_uverbs_async_handler(context_ptr,
+                                event->element.qp->uobject->user_handle,
+                                event->event);
+}
+
+static void ib_uverbs_event_handler(struct ib_event_handler *handler,
+                                    struct ib_event *event)
+{
+        struct ib_uverbs_file *file =
+                container_of(handler, struct ib_uverbs_file, event_handler);
+
+        ib_uverbs_async_handler(file, event->element.port_num, event->event);
+}
+
+static int ib_uverbs_event_init(struct ib_uverbs_event_file *file,
+                                struct ib_uverbs_file *uverbs_file)
+{
+        struct file *filp;
+
+        spin_lock_init(&file->lock);
+        INIT_LIST_HEAD(&file->event_list);
+        init_waitqueue_head(&file->poll_wait);
+        file->uverbs_file = uverbs_file;
+
+        file->fd = get_unused_fd();
+        if (file->fd < 0)
+                return file->fd;
+
+        filp = get_empty_filp();
+        if (!filp) {
+                put_unused_fd(file->fd);
+                return -ENFILE;
+        }
+
+        filp->f_op         = &uverbs_event_fops;
+        filp->f_vfsmnt     = mntget(uverbs_event_mnt);
+        filp->f_dentry     = dget(uverbs_event_mnt->mnt_root);
+        filp->f_mapping    = filp->f_dentry->d_inode->i_mapping;
+        filp->f_flags      = O_RDONLY;
+        filp->f_mode       = FMODE_READ;
+        filp->private_data = file;
+
+        fd_install(file->fd, filp);
+
+        return 0;
+}
+
+static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
+                             size_t count, loff_t *pos)
+{
+        struct ib_uverbs_file *file = filp->private_data;
+        struct ib_uverbs_cmd_hdr hdr;
+
+        if (count < sizeof hdr)
+                return -EINVAL;
+
+        if (copy_from_user(&hdr, buf, sizeof hdr))
+                return -EFAULT;
+
+        if (hdr.in_words * 4 != count)
+                return -EINVAL;
+
+        if (hdr.command < 0 || hdr.command >= ARRAY_SIZE(uverbs_cmd_table))
+                return -EINVAL;
+
+        if (!file->ucontext                               &&
+            hdr.command != IB_USER_VERBS_CMD_QUERY_PARAMS &&
+            hdr.command != IB_USER_VERBS_CMD_GET_CONTEXT)
+                return -EINVAL;
+
+        return uverbs_cmd_table[hdr.command](file, buf + sizeof hdr,
+                                             hdr.in_words * 4, hdr.out_words * 4);
+}
+
+static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+        struct ib_uverbs_file *file = filp->private_data;
+
+        if (!file->ucontext)
+                return -ENODEV;
+        else
+                return file->device->ib_dev->mmap(file->ucontext, vma);
+}
+
+static int ib_uverbs_open(struct inode *inode, struct file *filp)
+{
+        struct ib_uverbs_device *dev =
+                container_of(inode->i_cdev, struct ib_uverbs_device, dev);
+        struct ib_uverbs_file *file;
+        int i = 0;
+        int ret;
+
+        if (!try_module_get(dev->ib_dev->owner))
+                return -ENODEV;
+
+        file = kmalloc(sizeof *file +
+                       (dev->num_comp - 1) * sizeof (struct ib_uverbs_event_file),
+                       GFP_KERNEL);
+        if (!file)
+                return -ENOMEM;
+
+        file->device = dev;
+        kref_init(&file->ref);
+
+        file->ucontext = NULL;
+
+        ret = ib_uverbs_event_init(&file->async_file, file);
+        if (ret)
+                goto err;
+
+        file->async_file.is_async = 1;
+
+        kref_get(&file->ref);
+
+        for (i = 0; i < dev->num_comp; ++i) {
+                ret = ib_uverbs_event_init(&file->comp_file[i], file);
+                if (ret)
+                        goto err_async;
+                kref_get(&file->ref);
+                file->comp_file[i].is_async = 0;
+        }
+
+
+        filp->private_data = file;
+
+        INIT_IB_EVENT_HANDLER(&file->event_handler, dev->ib_dev,
+                              ib_uverbs_event_handler);
+        if (ib_register_event_handler(&file->event_handler))
+                goto err_async;
+
+        return 0;
+
+err_async:
+        while (i--)
+                ib_uverbs_event_release(&file->comp_file[i]);
+
+        ib_uverbs_event_release(&file->async_file);
+
+err:
+        kref_put(&file->ref, ib_uverbs_release_file);
+
+        return ret;
+}
+
+static int ib_uverbs_close(struct inode *inode, struct file *filp)
+{
+        struct ib_uverbs_file *file = filp->private_data;
+        int i;
+
+        ib_unregister_event_handler(&file->event_handler);
+        ib_uverbs_event_release(&file->async_file);
+        ib_dealloc_ucontext(file->ucontext);
+
+        for (i = 0; i < file->device->num_comp; ++i)
+                ib_uverbs_event_release(&file->comp_file[i]);
+
+        kref_put(&file->ref, ib_uverbs_release_file);
+
+        return 0;
+}
+
+static struct file_operations uverbs_fops = {
+        .owner   = THIS_MODULE,
+        .write   = ib_uverbs_write,
+        .open    = ib_uverbs_open,
+        .release = ib_uverbs_close
+};
+
+static struct file_operations uverbs_mmap_fops = {
+        .owner   = THIS_MODULE,
+        .write   = ib_uverbs_write,
+        .mmap    = ib_uverbs_mmap,
+        .open    = ib_uverbs_open,
+        .release = ib_uverbs_close
+};
+
+static struct ib_client uverbs_client = {
+        .name   = "uverbs",
+        .add    = ib_uverbs_add_one,
+        .remove = ib_uverbs_remove_one
+};
+
+static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
+{
+        struct ib_uverbs_device *dev =
+                container_of(class_dev, struct ib_uverbs_device, class_dev);
+
+        return sprintf(buf, "%s\n", dev->ib_dev->name);
+}
+static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
+
+static void ib_uverbs_release_class_dev(struct class_device *class_dev)
+{
+        struct ib_uverbs_device *dev =
+                container_of(class_dev, struct ib_uverbs_device, class_dev);
+
+        cdev_del(&dev->dev);
+        clear_bit(dev->devnum, dev_map);
+        kfree(dev);
+}
+
+static struct class uverbs_class = {
+        .name    = "infiniband_verbs",
+        .release = ib_uverbs_release_class_dev
+};
+
+static ssize_t show_abi_version(struct class *class, char *buf)
+{
+        return sprintf(buf, "%d\n", IB_USER_VERBS_ABI_VERSION);
+}
+static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
+
+static void ib_uverbs_add_one(struct ib_device *device)
+{
+        struct ib_uverbs_device *uverbs_dev;
+
+        if (!device->alloc_ucontext)
+                return;
+
+        uverbs_dev = kmalloc(sizeof *uverbs_dev, GFP_KERNEL);
+        if (!uverbs_dev)
+                return;
+
+        memset(uverbs_dev, 0, sizeof *uverbs_dev);
+
+        spin_lock(&map_lock);
+        uverbs_dev->devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
+        if (uverbs_dev->devnum >= IB_UVERBS_MAX_DEVICES) {
+                spin_unlock(&map_lock);
+                goto err;
+        }
+        set_bit(uverbs_dev->devnum, dev_map);
+        spin_unlock(&map_lock);
+
+        uverbs_dev->ib_dev   = device;
+        uverbs_dev->num_comp = 1;
+
+        if (device->mmap)
+                cdev_init(&uverbs_dev->dev, &uverbs_mmap_fops);
+        else
+                cdev_init(&uverbs_dev->dev, &uverbs_fops);
+        uverbs_dev->dev.owner = THIS_MODULE;
+        kobject_set_name(&uverbs_dev->dev.kobj, "uverbs%d", uverbs_dev->devnum);
+        if (cdev_add(&uverbs_dev->dev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
+                goto err;
+
+        uverbs_dev->class_dev.class = &uverbs_class;
+        uverbs_dev->class_dev.dev   = device->dma_device;
+        uverbs_dev->class_dev.devt  = uverbs_dev->dev.dev;
+        snprintf(uverbs_dev->class_dev.class_id, BUS_ID_SIZE, "uverbs%d", uverbs_dev->devnum);
+        if (class_device_register(&uverbs_dev->class_dev))
+                goto err_cdev;
+
+        if (class_device_create_file(&uverbs_dev->class_dev, &class_device_attr_ibdev))
+                goto err_class;
+
+        ib_set_client_data(device, &uverbs_client, uverbs_dev);
+
+        return;
+
+err_class:
+        class_device_unregister(&uverbs_dev->class_dev);
+
+err_cdev:
+        cdev_del(&uverbs_dev->dev);
+        clear_bit(uverbs_dev->devnum, dev_map);
+
+err:
+        kfree(uverbs_dev);
+        return;
+}
+
+static void ib_uverbs_remove_one(struct ib_device *device)
+{
+        struct ib_uverbs_device *uverbs_dev = ib_get_client_data(device, &uverbs_client);
+
+        if (!uverbs_dev)
+                return;
+
+        class_device_unregister(&uverbs_dev->class_dev);
+}
+
+static struct super_block *uverbs_event_get_sb(struct file_system_type *fs_type, int flags,
+                                               const char *dev_name, void *data)
+{
+        return get_sb_pseudo(fs_type, "infinibandevent:", NULL,
+                             INFINIBANDEVENTFS_MAGIC);
+}
+
+static struct file_system_type uverbs_event_fs = {
+        /* No owner field so module can be unloaded */
+        .name    = "infinibandeventfs",
+        .get_sb  = uverbs_event_get_sb,
+        .kill_sb = kill_litter_super
+};
+
+static int __init ib_uverbs_init(void)
+{
+        int ret;
+
+        spin_lock_init(&map_lock);
+
+        ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
+                                     "infiniband_verbs");
+        if (ret) {
+                printk(KERN_ERR "user_verbs: couldn't register device number\n");
+                goto out;
+        }
+
+        ret = class_register(&uverbs_class);
+        if (ret) {
+                printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
+                goto out_chrdev;
+        }
+
+        ret = class_create_file(&uverbs_class, &class_attr_abi_version);
+        if (ret) {
+                printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
+                goto out_class;
+        }
+
+        ret = register_filesystem(&uverbs_event_fs);
+        if (ret) {
+                printk(KERN_ERR "user_verbs: couldn't register infinibandeventfs\n");
+                goto out_class;
+        }
+
+        uverbs_event_mnt = kern_mount(&uverbs_event_fs);
+        if (IS_ERR(uverbs_event_mnt)) {
+                ret = PTR_ERR(uverbs_event_mnt);
+                printk(KERN_ERR "user_verbs: couldn't mount infinibandeventfs\n");
+                goto out_fs;
+        }
+
+        ret = ib_register_client(&uverbs_client);
+        if (ret) {
+                printk(KERN_ERR "user_verbs: couldn't register client\n");
+                goto out_mnt;
+        }
+
+        return 0;
+
+out_mnt:
+        mntput(uverbs_event_mnt);
+
+out_fs:
+        unregister_filesystem(&uverbs_event_fs);
+
+out_class:
+        class_unregister(&uverbs_class);
+
+out_chrdev:
+        unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
+
+out:
+        return ret;
+}
+
+static void __exit ib_uverbs_cleanup(void)
+{
+        ib_unregister_client(&uverbs_client);
+        mntput(uverbs_event_mnt);
+        unregister_filesystem(&uverbs_event_fs);
+        class_unregister(&uverbs_class);
+        unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
+}
+
+module_init(ib_uverbs_init);
+module_exit(ib_uverbs_cleanup);