Initial import

1 files changed, 1039 insertions, 0 deletions

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
new file mode 100644
index 000000000..88cce9bb7
--- /dev/null
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -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);