path: root/drivers/infiniband/core/user_mad.c

/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2008 Cisco. 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/cdev.h>
#include <linux/dma-mapping.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/kref.h>
#include <linux/compat.h>
#include <linux/sched.h>
#include <linux/semaphore.h>
#include <linux/slab.h>

#include <asm/uaccess.h>

#include <rdma/ib_mad.h>
#include <rdma/ib_user_mad.h>

MODULE_AUTHOR("Roland Dreier");
MODULE_DESCRIPTION("InfiniBand userspace MAD packet access");
MODULE_LICENSE("Dual BSD/GPL");

enum {
	IB_UMAD_MAX_PORTS  = 64,
	IB_UMAD_MAX_AGENTS = 32,

	IB_UMAD_MAJOR      = 231,
	IB_UMAD_MINOR_BASE = 0
};

/*
 * Our lifetime rules for these structs are the following:
 * device special file is opened, we take a reference on the
 * ib_umad_port's struct ib_umad_device. We drop these
 * references in the corresponding close().
 *
 * In addition to references coming from open character devices, there
 * is one more reference to each ib_umad_device representing the
 * module's reference taken when allocating the ib_umad_device in
 * ib_umad_add_one().
 *
 * When destroying an ib_umad_device, we drop the module's reference.
 */

struct ib_umad_port {
	struct cdev           cdev;
	struct device	      *dev;

	struct cdev           sm_cdev;
	struct device	      *sm_dev;
	struct semaphore       sm_sem;

	struct mutex	       file_mutex;
	struct list_head       file_list;

	struct ib_device      *ib_dev;
	struct ib_umad_device *umad_dev;
	int                    dev_num;
	u8                     port_num;
};

struct ib_umad_device {
	int                  start_port, end_port;
	struct kref          ref;
	struct ib_umad_port  port[0];
};

struct ib_umad_file {
	struct mutex		mutex;
	struct ib_umad_port    *port;
	struct list_head	recv_list;
	struct list_head	send_list;
	struct list_head	port_list;
	spinlock_t		send_lock;
	wait_queue_head_t	recv_wait;
	struct ib_mad_agent    *agent[IB_UMAD_MAX_AGENTS];
	int			agents_dead;
	u8			use_pkey_index;
	u8			already_used;
};

struct ib_umad_packet {
	struct ib_mad_send_buf *msg;
	struct ib_mad_recv_wc  *recv_wc;
	struct list_head   list;
	int		   length;
	struct ib_user_mad mad;
};

static struct class *umad_class;

static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);

static DEFINE_SPINLOCK(port_lock);
static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS);

static void ib_umad_add_one(struct ib_device *device);
static