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

/*
 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Intel Corporation.  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: ucm.c 2594 2005-06-13 19:46:02Z libor $
 */
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/mutex.h>

#include <asm/uaccess.h>

#include <rdma/ib_cm.h>
#include <rdma/ib_user_cm.h>

MODULE_AUTHOR("Libor Michalek");
MODULE_DESCRIPTION("InfiniBand userspace Connection Manager access");
MODULE_LICENSE("Dual BSD/GPL");

struct ib_ucm_device {
	int			devnum;
	struct cdev		dev;
	struct class_device	class_dev;
	struct ib_device	*ib_dev;
};

struct ib_ucm_file {
	struct semaphore mutex;
	struct file *filp;
	struct ib_ucm_device *device;

	struct list_head  ctxs;
	struct list_head  events;
	wait_queue_head_t poll_wait;
};

struct ib_ucm_context {
	int                 id;
	wait_queue_head_t   wait;
	atomic_t            ref;
	int		    events_reported;

	struct ib_ucm_file *file;
	struct ib_cm_id    *cm_id;
	__u64		   uid;

	struct list_head    events;    /* list of pending events. */
	struct list_head    file_list; /* member in file ctx list */
};

struct ib_ucm_event {
	struct ib_ucm_context *ctx;
	struct list_head file_list; /* member in file event list */
	struct list_head ctx_list;  /* member in ctx event list */

	struct ib_cm_id *cm_id;
	struct ib_ucm_event_resp resp;
	void *data;
	void *info;
	int data_len;
	int info_len;
};

enum {
	IB_UCM_MAJOR = 231,
	IB_UCM_BASE_MINOR = 224,
	IB_UCM_MAX_DEVICES = 32
};

#define IB_UCM_BASE_DEV MKDEV(IB_UCM_MAJOR, IB_UCM_BASE_MINOR)

static void ib_ucm_add_one(struct ib_device *device);
static void ib_ucm_remove_one(struct ib_device *device);

static struct ib_client ucm_client = {
	.name   = "ucm",
	.add    = ib_ucm_add_one,
	.remove = ib_ucm_remove_one
};

static DEFINE_MUTEX(ctx_id_mutex);
static DEFINE_IDR(ctx_id_table);
static DECLARE_BITMAP(dev_map, IB_UCM_MAX_DEVICES);

static struct ib_ucm_context *ib_ucm_ctx_get(struct ib_ucm_file *file, int id)
{
	struct ib_ucm_context *ctx;

	mutex_lock(&ctx_id_mutex);
	ctx = idr_find(&ctx_id_table, id);
	if (!ctx)
		ctx = ERR_PTR(-ENOENT);
	else if (ctx->file != file)
		ctx = ERR_PTR(-EINVAL);
	else
		atomic_inc(&ctx->ref);
	mutex_unlock(&ctx_id_mutex);

	return ctx;
}

static void ib_ucm_ctx_put(struct ib_ucm_context *ctx)
{
	if (atomic_dec_and_test(&ctx->ref))
		wake_up(&ctx->wait);
}

static