Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / core / uverbs_main.c
diff --git a/kernel/drivers/infiniband/core/uverbs_main.c b/kernel/drivers/infiniband/core/uverbs_main.c
new file mode 100644 (file)
index 0000000..88cce9b
--- /dev/null
@@ -0,0 +1,1039 @@
+/*
+ * Copyright (c) 2005 Topspin Communications.  All rights reserved.
+ * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
+ * Copyright (c) 2005 PathScale, Inc. 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.
+ */
+
+#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/sched.h>
+#include <linux/file.h>
+#include <linux/cdev.h>
+#include <linux/anon_inodes.h>
+#include <linux/slab.h>
+
+#include <asm/uaccess.h>
+
+#include "uverbs.h"
+
+MODULE_AUTHOR("Roland Dreier");
+MODULE_DESCRIPTION("InfiniBand userspace verbs access");
+MODULE_LICENSE("Dual BSD/GPL");
+
+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)
+
+static struct class *uverbs_class;
+
+DEFINE_SPINLOCK(ib_uverbs_idr_lock);
+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);
+DEFINE_IDR(ib_uverbs_srq_idr);
+DEFINE_IDR(ib_uverbs_xrcd_idr);
+DEFINE_IDR(ib_uverbs_rule_idr);
+
+static DEFINE_SPINLOCK(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_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_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_REREG_MR]            = ib_uverbs_rereg_mr,
+       [IB_USER_VERBS_CMD_DEREG_MR]            = ib_uverbs_dereg_mr,
+       [IB_USER_VERBS_CMD_ALLOC_MW]            = ib_uverbs_alloc_mw,
+       [IB_USER_VERBS_CMD_DEALLOC_MW]          = ib_uverbs_dealloc_mw,
+       [IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
+       [IB_USER_VERBS_CMD_CREATE_CQ]           = ib_uverbs_create_cq,
+       [IB_USER_VERBS_CMD_RESIZE_CQ]           = ib_uverbs_resize_cq,
+       [IB_USER_VERBS_CMD_POLL_CQ]             = ib_uverbs_poll_cq,
+       [IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]       = ib_uverbs_req_notify_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_QUERY_QP]            = ib_uverbs_query_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_POST_SEND]           = ib_uverbs_post_send,
+       [IB_USER_VERBS_CMD_POST_RECV]           = ib_uverbs_post_recv,
+       [IB_USER_VERBS_CMD_POST_SRQ_RECV]       = ib_uverbs_post_srq_recv,
+       [IB_USER_VERBS_CMD_CREATE_AH]           = ib_uverbs_create_ah,
+       [IB_USER_VERBS_CMD_DESTROY_AH]          = ib_uverbs_destroy_ah,
+       [IB_USER_VERBS_CMD_ATTACH_MCAST]        = ib_uverbs_attach_mcast,
+       [IB_USER_VERBS_CMD_DETACH_MCAST]        = ib_uverbs_detach_mcast,
+       [IB_USER_VERBS_CMD_CREATE_SRQ]          = ib_uverbs_create_srq,
+       [IB_USER_VERBS_CMD_MODIFY_SRQ]          = ib_uverbs_modify_srq,
+       [IB_USER_VERBS_CMD_QUERY_SRQ]           = ib_uverbs_query_srq,
+       [IB_USER_VERBS_CMD_DESTROY_SRQ]         = ib_uverbs_destroy_srq,
+       [IB_USER_VERBS_CMD_OPEN_XRCD]           = ib_uverbs_open_xrcd,
+       [IB_USER_VERBS_CMD_CLOSE_XRCD]          = ib_uverbs_close_xrcd,
+       [IB_USER_VERBS_CMD_CREATE_XSRQ]         = ib_uverbs_create_xsrq,
+       [IB_USER_VERBS_CMD_OPEN_QP]             = ib_uverbs_open_qp,
+};
+
+static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
+                                   struct ib_udata *ucore,
+                                   struct ib_udata *uhw) = {
+       [IB_USER_VERBS_EX_CMD_CREATE_FLOW]      = ib_uverbs_ex_create_flow,
+       [IB_USER_VERBS_EX_CMD_DESTROY_FLOW]     = ib_uverbs_ex_destroy_flow,
+       [IB_USER_VERBS_EX_CMD_QUERY_DEVICE]     = ib_uverbs_ex_query_device,
+};
+
+static void ib_uverbs_add_one(struct ib_device *device);
+static void ib_uverbs_remove_one(struct ib_device *device);
+
+static void ib_uverbs_release_dev(struct kref *ref)
+{
+       struct ib_uverbs_device *dev =
+               container_of(ref, struct ib_uverbs_device, ref);
+
+       complete(&dev->comp);
+}
+
+static void ib_uverbs_release_event_file(struct kref *ref)
+{
+       struct ib_uverbs_event_file *file =
+               container_of(ref, struct ib_uverbs_event_file, ref);
+
+       kfree(file);
+}
+
+void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
+                         struct ib_uverbs_event_file *ev_file,
+                         struct ib_ucq_object *uobj)
+{
+       struct ib_uverbs_event *evt, *tmp;
+
+       if (ev_file) {
+               spin_lock_irq(&ev_file->lock);
+               list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
+                       list_del(&evt->list);
+                       kfree(evt);
+               }
+               spin_unlock_irq(&ev_file->lock);
+
+               kref_put(&ev_file->ref, ib_uverbs_release_event_file);
+       }
+
+       spin_lock_irq(&file->async_file->lock);
+       list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
+               list_del(&evt->list);
+               kfree(evt);
+       }
+       spin_unlock_irq(&file->async_file->lock);
+}
+
+void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
+                             struct ib_uevent_object *uobj)
+{
+       struct ib_uverbs_event *evt, *tmp;
+
+       spin_lock_irq(&file->async_file->lock);
+       list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
+               list_del(&evt->list);
+               kfree(evt);
+       }
+       spin_unlock_irq(&file->async_file->lock);
+}
+
+static void ib_uverbs_detach_umcast(struct ib_qp *qp,
+                                   struct ib_uqp_object *uobj)
+{
+       struct ib_uverbs_mcast_entry *mcast, *tmp;
+
+       list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
+               ib_detach_mcast(qp, &mcast->gid, mcast->lid);
+               list_del(&mcast->list);
+               kfree(mcast);
+       }
+}
+
+static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
+                                     struct ib_ucontext *context)
+{
+       struct ib_uobject *uobj, *tmp;
+
+       if (!context)
+               return 0;
+
+       context->closing = 1;
+
+       list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
+               struct ib_ah *ah = uobj->object;
+
+               idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
+               ib_destroy_ah(ah);
+               kfree(uobj);
+       }
+
+       /* Remove MWs before QPs, in order to support type 2A MWs. */
+       list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
+               struct ib_mw *mw = uobj->object;
+
+               idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
+               ib_dealloc_mw(mw);
+               kfree(uobj);
+       }
+
+       list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
+               struct ib_flow *flow_id = uobj->object;
+
+               idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
+               ib_destroy_flow(flow_id);
+               kfree(uobj);
+       }
+
+       list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
+               struct ib_qp *qp = uobj->object;
+               struct ib_uqp_object *uqp =
+                       container_of(uobj, struct ib_uqp_object, uevent.uobject);
+
+               idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
+               if (qp != qp->real_qp) {
+                       ib_close_qp(qp);
+               } else {
+                       ib_uverbs_detach_umcast(qp, uqp);
+                       ib_destroy_qp(qp);
+               }
+               ib_uverbs_release_uevent(file, &uqp->uevent);
+               kfree(uqp);
+       }
+
+       list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
+               struct ib_srq *srq = uobj->object;
+               struct ib_uevent_object *uevent =
+                       container_of(uobj, struct ib_uevent_object, uobject);
+
+               idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
+               ib_destroy_srq(srq);
+               ib_uverbs_release_uevent(file, uevent);
+               kfree(uevent);
+       }
+
+       list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
+               struct ib_cq *cq = uobj->object;
+               struct ib_uverbs_event_file *ev_file = cq->cq_context;
+               struct ib_ucq_object *ucq =
+                       container_of(uobj, struct ib_ucq_object, uobject);
+
+               idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
+               ib_destroy_cq(cq);
+               ib_uverbs_release_ucq(file, ev_file, ucq);
+               kfree(ucq);
+       }
+
+       list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
+               struct ib_mr *mr = uobj->object;
+
+               idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
+               ib_dereg_mr(mr);
+               kfree(uobj);
+       }
+
+       mutex_lock(&file->device->xrcd_tree_mutex);
+       list_for_each_entry_safe(uobj, tmp, &context->xrcd_list, list) {
+               struct ib_xrcd *xrcd = uobj->object;
+               struct ib_uxrcd_object *uxrcd =
+                       container_of(uobj, struct ib_uxrcd_object, uobject);
+
+               idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
+               ib_uverbs_dealloc_xrcd(file->device, xrcd);
+               kfree(uxrcd);
+       }
+       mutex_unlock(&file->device->xrcd_tree_mutex);
+
+       list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
+               struct ib_pd *pd = uobj->object;
+
+               idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
+               ib_dealloc_pd(pd);
+               kfree(uobj);
+       }
+
+       put_pid(context->tgid);
+
+       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);
+       kref_put(&file->device->ref, ib_uverbs_release_dev);
+
+       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;
+       struct ib_uverbs_event *event;
+       int eventsz;
+       int ret = 0;
+
+       spin_lock_irq(&file->lock);
+
+       while (list_empty(&file->event_list)) {
+               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)))
+                       return -ERESTARTSYS;
+
+               spin_lock_irq(&file->lock);
+       }
+
+       event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
+
+       if (file->is_async)
+               eventsz = sizeof (struct ib_uverbs_async_event_desc);
+       else
+               eventsz = sizeof (struct ib_uverbs_comp_event_desc);
+
+       if (eventsz > count) {
+               ret   = -EINVAL;
+               event = NULL;
+       } else {
+               list_del(file->event_list.next);
+               if (event->counter) {
+                       ++(*event->counter);
+                       list_del(&event->obj_list);
+               }
+       }
+
+       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 (!list_empty(&file->event_list))
+               pollflags = POLLIN | POLLRDNORM;
+       spin_unlock_irq(&file->lock);
+
+       return pollflags;
+}
+
+static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
+{
+       struct ib_uverbs_event_file *file = filp->private_data;
+
+       return fasync_helper(fd, filp, on, &file->async_queue);
+}
+
+static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
+{
+       struct ib_uverbs_event_file *file = filp->private_data;
+       struct ib_uverbs_event *entry, *tmp;
+
+       spin_lock_irq(&file->lock);
+       file->is_closed = 1;
+       list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
+               if (entry->counter)
+                       list_del(&entry->obj_list);
+               kfree(entry);
+       }
+       spin_unlock_irq(&file->lock);
+
+       if (file->is_async) {
+               ib_unregister_event_handler(&file->uverbs_file->event_handler);
+               kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
+       }
+       kref_put(&file->ref, ib_uverbs_release_event_file);
+
+       return 0;
+}
+
+static const struct file_operations uverbs_event_fops = {
+       .owner   = THIS_MODULE,
+       .read    = ib_uverbs_event_read,
+       .poll    = ib_uverbs_event_poll,
+       .release = ib_uverbs_event_close,
+       .fasync  = ib_uverbs_event_fasync,
+       .llseek  = no_llseek,
+};
+
+void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
+{
+       struct ib_uverbs_event_file    *file = cq_context;
+       struct ib_ucq_object           *uobj;
+       struct ib_uverbs_event         *entry;
+       unsigned long                   flags;
+
+       if (!file)
+               return;
+
+       spin_lock_irqsave(&file->lock, flags);
+       if (file->is_closed) {
+               spin_unlock_irqrestore(&file->lock, flags);
+               return;
+       }
+
+       entry = kmalloc(sizeof *entry, GFP_ATOMIC);
+       if (!entry) {
+               spin_unlock_irqrestore(&file->lock, flags);
+               return;
+       }
+
+       uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
+
+       entry->desc.comp.cq_handle = cq->uobject->user_handle;
+       entry->counter             = &uobj->comp_events_reported;
+
+       list_add_tail(&entry->list, &file->event_list);
+       list_add_tail(&entry->obj_list, &uobj->comp_list);
+       spin_unlock_irqrestore(&file->lock, flags);
+
+       wake_up_interruptible(&file->poll_wait);
+       kill_fasync(&file->async_queue, SIGIO, POLL_IN);
+}
+
+static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
+                                   __u64 element, __u64 event,
+                                   struct list_head *obj_list,
+                                   u32 *counter)
+{
+       struct ib_uverbs_event *entry;
+       unsigned long flags;
+
+       spin_lock_irqsave(&file->async_file->lock, flags);
+       if (file->async_file->is_closed) {
+               spin_unlock_irqrestore(&file->async_file->lock, flags);
+               return;
+       }
+
+       entry = kmalloc(sizeof *entry, GFP_ATOMIC);
+       if (!entry) {
+               spin_unlock_irqrestore(&file->async_file->lock, flags);
+               return;
+       }
+
+       entry->desc.async.element    = element;
+       entry->desc.async.event_type = event;
+       entry->desc.async.reserved   = 0;
+       entry->counter               = counter;
+
+       list_add_tail(&entry->list, &file->async_file->event_list);
+       if (obj_list)
+               list_add_tail(&entry->obj_list, obj_list);
+       spin_unlock_irqrestore(&file->async_file->lock, flags);
+
+       wake_up_interruptible(&file->async_file->poll_wait);
+       kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
+}
+
+void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
+{
+       struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
+                                                 struct ib_ucq_object, uobject);
+
+       ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
+                               event->event, &uobj->async_list,
+                               &uobj->async_events_reported);
+}
+
+void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
+{
+       struct ib_uevent_object *uobj;
+
+       /* for XRC target qp's, check that qp is live */
+       if (!event->element.qp->uobject || !event->element.qp->uobject->live)
+               return;
+
+       uobj = container_of(event->element.qp->uobject,
+                           struct ib_uevent_object, uobject);
+
+       ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
+                               event->event, &uobj->event_list,
+                               &uobj->events_reported);
+}
+
+void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
+{
+       struct ib_uevent_object *uobj;
+
+       uobj = container_of(event->element.srq->uobject,
+                           struct ib_uevent_object, uobject);
+
+       ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
+                               event->event, &uobj->event_list,
+                               &uobj->events_reported);
+}
+
+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,
+                               NULL, NULL);
+}
+
+struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
+                                       int is_async)
+{
+       struct ib_uverbs_event_file *ev_file;
+       struct file *filp;
+
+       ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL);
+       if (!ev_file)
+               return ERR_PTR(-ENOMEM);
+
+       kref_init(&ev_file->ref);
+       spin_lock_init(&ev_file->lock);
+       INIT_LIST_HEAD(&ev_file->event_list);
+       init_waitqueue_head(&ev_file->poll_wait);
+       ev_file->uverbs_file = uverbs_file;
+       ev_file->async_queue = NULL;
+       ev_file->is_async    = is_async;
+       ev_file->is_closed   = 0;
+
+       filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
+                                 ev_file, O_RDONLY);
+       if (IS_ERR(filp))
+               kfree(ev_file);
+
+       return filp;
+}
+
+/*
+ * Look up a completion event file by FD.  If lookup is successful,
+ * takes a ref to the event file struct that it returns; if
+ * unsuccessful, returns NULL.
+ */
+struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
+{
+       struct ib_uverbs_event_file *ev_file = NULL;
+       struct fd f = fdget(fd);
+
+       if (!f.file)
+               return NULL;
+
+       if (f.file->f_op != &uverbs_event_fops)
+               goto out;
+
+       ev_file = f.file->private_data;
+       if (ev_file->is_async) {
+               ev_file = NULL;
+               goto out;
+       }
+
+       kref_get(&ev_file->ref);
+
+out:
+       fdput(f);
+       return ev_file;
+}
+
+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;
+       __u32 flags;
+
+       if (count < sizeof hdr)
+               return -EINVAL;
+
+       if (copy_from_user(&hdr, buf, sizeof hdr))
+               return -EFAULT;
+
+       flags = (hdr.command &
+                IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
+
+       if (!flags) {
+               __u32 command;
+
+               if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
+                                          IB_USER_VERBS_CMD_COMMAND_MASK))
+                       return -EINVAL;
+
+               command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
+
+               if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
+                   !uverbs_cmd_table[command])
+                       return -EINVAL;
+
+               if (!file->ucontext &&
+                   command != IB_USER_VERBS_CMD_GET_CONTEXT)
+                       return -EINVAL;
+
+               if (!(file->device->ib_dev->uverbs_cmd_mask & (1ull << command)))
+                       return -ENOSYS;
+
+               if (hdr.in_words * 4 != count)
+                       return -EINVAL;
+
+               return uverbs_cmd_table[command](file,
+                                                buf + sizeof(hdr),
+                                                hdr.in_words * 4,
+                                                hdr.out_words * 4);
+
+       } else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
+               __u32 command;
+
+               struct ib_uverbs_ex_cmd_hdr ex_hdr;
+               struct ib_udata ucore;
+               struct ib_udata uhw;
+               int err;
+               size_t written_count = count;
+
+               if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
+                                          IB_USER_VERBS_CMD_COMMAND_MASK))
+                       return -EINVAL;
+
+               command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
+
+               if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
+                   !uverbs_ex_cmd_table[command])
+                       return -ENOSYS;
+
+               if (!file->ucontext)
+                       return -EINVAL;
+
+               if (!(file->device->ib_dev->uverbs_ex_cmd_mask & (1ull << command)))
+                       return -ENOSYS;
+
+               if (count < (sizeof(hdr) + sizeof(ex_hdr)))
+                       return -EINVAL;
+
+               if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
+                       return -EFAULT;
+
+               count -= sizeof(hdr) + sizeof(ex_hdr);
+               buf += sizeof(hdr) + sizeof(ex_hdr);
+
+               if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count)
+                       return -EINVAL;
+
+               if (ex_hdr.cmd_hdr_reserved)
+                       return -EINVAL;
+
+               if (ex_hdr.response) {
+                       if (!hdr.out_words && !ex_hdr.provider_out_words)
+                               return -EINVAL;
+
+                       if (!access_ok(VERIFY_WRITE,
+                                      (void __user *) (unsigned long) ex_hdr.response,
+                                      (hdr.out_words + ex_hdr.provider_out_words) * 8))
+                               return -EFAULT;
+               } else {
+                       if (hdr.out_words || ex_hdr.provider_out_words)
+                               return -EINVAL;
+               }
+
+               INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
+                                      hdr.in_words * 8, hdr.out_words * 8);
+
+               INIT_UDATA_BUF_OR_NULL(&uhw,
+                                      buf + ucore.inlen,
+                                      (unsigned long) ex_hdr.response + ucore.outlen,
+                                      ex_hdr.provider_in_words * 8,
+                                      ex_hdr.provider_out_words * 8);
+
+               err = uverbs_ex_cmd_table[command](file,
+                                                  &ucore,
+                                                  &uhw);
+
+               if (err)
+                       return err;
+
+               return written_count;
+       }
+
+       return -ENOSYS;
+}
+
+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);
+}
+
+/*
+ * ib_uverbs_open() does not need the BKL:
+ *
+ *  - the ib_uverbs_device structures are properly reference counted and
+ *    everything else is purely local to the file being created, so
+ *    races against other open calls are not a problem;
+ *  - there is no ioctl method to race against;
+ *  - the open method will either immediately run -ENXIO, or all
+ *    required initialization will be done.
+ */
+static int ib_uverbs_open(struct inode *inode, struct file *filp)
+{
+       struct ib_uverbs_device *dev;
+       struct ib_uverbs_file *file;
+       int ret;
+
+       dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
+       if (dev)
+               kref_get(&dev->ref);
+       else
+               return -ENXIO;
+
+       if (!try_module_get(dev->ib_dev->owner)) {
+               ret = -ENODEV;
+               goto err;
+       }
+
+       file = kmalloc(sizeof *file, GFP_KERNEL);
+       if (!file) {
+               ret = -ENOMEM;
+               goto err_module;
+       }
+
+       file->device     = dev;
+       file->ucontext   = NULL;
+       file->async_file = NULL;
+       kref_init(&file->ref);
+       mutex_init(&file->mutex);
+
+       filp->private_data = file;
+
+       return nonseekable_open(inode, filp);
+
+err_module:
+       module_put(dev->ib_dev->owner);
+
+err:
+       kref_put(&dev->ref, ib_uverbs_release_dev);
+       return ret;
+}
+
+static int ib_uverbs_close(struct inode *inode, struct file *filp)
+{
+       struct ib_uverbs_file *file = filp->private_data;
+
+       ib_uverbs_cleanup_ucontext(file, file->ucontext);
+
+       if (file->async_file)
+               kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
+
+       kref_put(&file->ref, ib_uverbs_release_file);
+
+       return 0;
+}
+
+static const struct file_operations uverbs_fops = {
+       .owner   = THIS_MODULE,
+       .write   = ib_uverbs_write,
+       .open    = ib_uverbs_open,
+       .release = ib_uverbs_close,
+       .llseek  = no_llseek,
+};
+
+static const 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,
+       .llseek  = no_llseek,
+};
+
+static struct ib_client uverbs_client = {
+       .name   = "uverbs",
+       .add    = ib_uverbs_add_one,
+       .remove = ib_uverbs_remove_one
+};
+
+static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
+                         char *buf)
+{
+       struct ib_uverbs_device *dev = dev_get_drvdata(device);
+
+       if (!dev)
+               return -ENODEV;
+
+       return sprintf(buf, "%s\n", dev->ib_dev->name);
+}
+static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
+
+static ssize_t show_dev_abi_version(struct device *device,
+                                   struct device_attribute *attr, char *buf)
+{
+       struct ib_uverbs_device *dev = dev_get_drvdata(device);
+
+       if (!dev)
+               return -ENODEV;
+
+       return sprintf(buf, "%d\n", dev->ib_dev->uverbs_abi_ver);
+}
+static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
+
+static CLASS_ATTR_STRING(abi_version, S_IRUGO,
+                        __stringify(IB_USER_VERBS_ABI_VERSION));
+
+static dev_t overflow_maj;
+static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
+
+/*
+ * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
+ * requesting a new major number and doubling the number of max devices we
+ * support. It's stupid, but simple.
+ */
+static int find_overflow_devnum(void)
+{
+       int ret;
+
+       if (!overflow_maj) {
+               ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
+                                         "infiniband_verbs");
+               if (ret) {
+                       printk(KERN_ERR "user_verbs: couldn't register dynamic device number\n");
+                       return ret;
+               }
+       }
+
+       ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
+       if (ret >= IB_UVERBS_MAX_DEVICES)
+               return -1;
+
+       return ret;
+}
+
+static void ib_uverbs_add_one(struct ib_device *device)
+{
+       int devnum;
+       dev_t base;
+       struct ib_uverbs_device *uverbs_dev;
+
+       if (!device->alloc_ucontext)
+               return;
+
+       uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
+       if (!uverbs_dev)
+               return;
+
+       kref_init(&uverbs_dev->ref);
+       init_completion(&uverbs_dev->comp);
+       uverbs_dev->xrcd_tree = RB_ROOT;
+       mutex_init(&uverbs_dev->xrcd_tree_mutex);
+
+       spin_lock(&map_lock);
+       devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
+       if (devnum >= IB_UVERBS_MAX_DEVICES) {
+               spin_unlock(&map_lock);
+               devnum = find_overflow_devnum();
+               if (devnum < 0)
+                       goto err;
+
+               spin_lock(&map_lock);
+               uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
+               base = devnum + overflow_maj;
+               set_bit(devnum, overflow_map);
+       } else {
+               uverbs_dev->devnum = devnum;
+               base = devnum + IB_UVERBS_BASE_DEV;
+               set_bit(devnum, dev_map);
+       }
+       spin_unlock(&map_lock);
+
+       uverbs_dev->ib_dev           = device;
+       uverbs_dev->num_comp_vectors = device->num_comp_vectors;
+
+       cdev_init(&uverbs_dev->cdev, NULL);
+       uverbs_dev->cdev.owner = THIS_MODULE;
+       uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
+       kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
+       if (cdev_add(&uverbs_dev->cdev, base, 1))
+               goto err_cdev;
+
+       uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
+                                       uverbs_dev->cdev.dev, uverbs_dev,
+                                       "uverbs%d", uverbs_dev->devnum);
+       if (IS_ERR(uverbs_dev->dev))
+               goto err_cdev;
+
+       if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
+               goto err_class;
+       if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
+               goto err_class;
+
+       ib_set_client_data(device, &uverbs_client, uverbs_dev);
+
+       return;
+
+err_class:
+       device_destroy(uverbs_class, uverbs_dev->cdev.dev);
+
+err_cdev:
+       cdev_del(&uverbs_dev->cdev);
+       if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
+               clear_bit(devnum, dev_map);
+       else
+               clear_bit(devnum, overflow_map);
+
+err:
+       kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
+       wait_for_completion(&uverbs_dev->comp);
+       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;
+
+       dev_set_drvdata(uverbs_dev->dev, NULL);
+       device_destroy(uverbs_class, uverbs_dev->cdev.dev);
+       cdev_del(&uverbs_dev->cdev);
+
+       if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
+               clear_bit(uverbs_dev->devnum, dev_map);
+       else
+               clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
+
+       kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
+       wait_for_completion(&uverbs_dev->comp);
+       kfree(uverbs_dev);
+}
+
+static char *uverbs_devnode(struct device *dev, umode_t *mode)
+{
+       if (mode)
+               *mode = 0666;
+       return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
+}
+
+static int __init ib_uverbs_init(void)
+{
+       int ret;
+
+       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;
+       }
+
+       uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
+       if (IS_ERR(uverbs_class)) {
+               ret = PTR_ERR(uverbs_class);
+               printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
+               goto out_chrdev;
+       }
+
+       uverbs_class->devnode = uverbs_devnode;
+
+       ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
+       if (ret) {
+               printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
+               goto out_class;
+       }
+
+       ret = ib_register_client(&uverbs_client);
+       if (ret) {
+               printk(KERN_ERR "user_verbs: couldn't register client\n");
+               goto out_class;
+       }
+
+       return 0;
+
+out_class:
+       class_destroy(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);
+       class_destroy(uverbs_class);
+       unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
+       if (overflow_maj)
+               unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
+       idr_destroy(&ib_uverbs_pd_idr);
+       idr_destroy(&ib_uverbs_mr_idr);
+       idr_destroy(&ib_uverbs_mw_idr);
+       idr_destroy(&ib_uverbs_ah_idr);
+       idr_destroy(&ib_uverbs_cq_idr);
+       idr_destroy(&ib_uverbs_qp_idr);
+       idr_destroy(&ib_uverbs_srq_idr);
+}
+
+module_init(ib_uverbs_init);
+module_exit(ib_uverbs_cleanup);