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

/*
 * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
 * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
 * Copyright (c) 2005 Network Appliance, 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/dma-mapping.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/sysctl.h>

#include <rdma/iw_cm.h>
#include <rdma/ib_addr.h>
#include <rdma/iw_portmap.h>
#include <rdma/rdma_netlink.h>

#include "iwcm.h"

MODULE_AUTHOR("Tom Tucker");
MODULE_DESCRIPTION("iWARP CM");
MODULE_LICENSE("Dual BSD/GPL");

static const char * const iwcm_rej_reason_strs[] = {
	[ECONNRESET]			= "reset by remote host",
	[ECONNREFUSED]			= "refused by remote application",
	[ETIMEDOUT]			= "setup timeout",
};

const char *__attribute_const__ iwcm_reject_msg(int reason)
{
	size_t index;

	/* iWARP uses negative errnos */
	index = -reason;

	if (index < ARRAY_SIZE(iwcm_rej_reason_strs) &&
	    iwcm_rej_reason_strs[index])
		return iwcm_rej_reason_strs[index];
	else
		return "unrecognized reason";
}
EXPORT_SYMBOL(iwcm_reject_msg);

static struct rdma_nl_cbs iwcm_nl_cb_table[RDMA_NL_IWPM_NUM_OPS] = {
	[RDMA_NL_IWPM_REG_PID] = {.dump = iwpm_register_pid_cb},
	[RDMA_NL_IWPM_ADD_MAPPING] = {.dump = iwpm_add_mapping_cb},
	[RDMA_NL_IWPM_QUERY_MAPPING] = {.dump = iwpm_add_and_query_mapping_cb},
	[RDMA_NL_IWPM_REMOTE_INFO] = {.dump = iwpm_remote_info_cb},
	[RDMA_NL_IWPM_HANDLE_ERR] = {.dump = iwpm_mapping_error_cb},
	[RDMA_NL_IWPM_MAPINFO] = {.dump = iwpm_mapping_info_cb},
	[RDMA_NL_IWPM_MAPINFO_NUM] = {.dump = iwpm_ack_mapping_info_cb}
};

static struct workqueue_struct *iwcm_wq;
struct iwcm_work {
	struct work_struct work;
	struct iwcm_id_private *cm_id;
	struct list_head list;
	struct iw_cm_event event;
	struct list_head free_list;
};

static unsigned int default_backlog = 256;

static struct ctl_table_header *iwcm_ctl_table_hdr;
static struct ctl_table iwcm_ctl_table[] = {
	{
		.procname	= "default_backlog",
		.data		= &default_backlog,
		.maxlen		= sizeof(default_backlog),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{ }
};

/*
 * The following services provide a mechanism for pre-allocating iwcm_work
 * elements.  The design pre-allocates them  based on the cm_id type:
 *	LISTENING IDS: 	Get enough elements preallocated to handle the
 *			listen backlog.
 *	ACTIVE IDS:	4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
 *	PASSIVE IDS:	3: ESTABLISHED, DISCONNECT, CLOSE
 *
 * Allocating them in connect and listen avoids having to deal
 * with allocation failures on the event upcall from the provider (which
 * is called in the interrupt context).
 *
 * One exception is when creating the cm_id for incoming connection requests.
 * There are two cases:
 * 1) in the event upcall, cm_event_handler(), for a listening cm_id.  If
 *    the backlog is exceeded, then no more connection request events will
 *    be processed.  cm_event_handler() returns -ENOMEM in this case.  Its up
 *    to the provider to reject the connection request.
 * 2) in the connection request workqueue handler, cm_conn_req_handler().
 *    If work elements cannot be allocated for the new connect request cm_id,
 *    then IWCM will call the provider reject method.  This is ok since
 *    cm_conn_req_handler() runs in the workqueue thread context.
 */

static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
{
	struct iwcm_work *work;

	if (list_empty(&cm_id_priv->work_free_list))
		return NULL;
	work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
			  free_list);
	list_del_init(&work->free_list);
	return work;
}

static void put_work(struct iwcm_work *work)
{
	list_add(&work