[deliverable/linux.git] / net / rds / ib.c

/*
 * Copyright (c) 2006 Oracle.  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/kernel.h>
#include <linux/in.h>
#include <linux/if.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/if_arp.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include "rds.h"
#include "ib.h"

unsigned int fmr_pool_size = RDS_FMR_POOL_SIZE;
unsigned int fmr_message_size = RDS_FMR_SIZE + 1; /* +1 allows for unaligned MRs */
unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;

module_param(fmr_pool_size, int, 0444);
MODULE_PARM_DESC(fmr_pool_size, " Max number of fmr per HCA");
module_param(fmr_message_size, int, 0444);
MODULE_PARM_DESC(fmr_message_size, " Max size of a RDMA transfer");
module_param(rds_ib_retry_count, int, 0444);
MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");

struct list_head rds_ib_devices;

/* NOTE: if also grabbing ibdev lock, grab this first */
DEFINE_SPINLOCK(ib_nodev_conns_lock);
LIST_HEAD(ib_nodev_conns);

void rds_ib_nodev_connect(void)
{
	struct rds_ib_connection *ic;

	spin_lock(&ib_nodev_conns_lock);
	list_for_each_entry(ic, &ib_nodev_conns, ib_node)
		rds_conn_connect_if_down(ic->conn);
	spin_unlock(&ib_nodev_conns_lock);
}

void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
{
	struct rds_ib_connection *ic;
	unsigned long flags;

	spin_lock_irqsave(&rds_ibdev->spinlock, flags);
	list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
		rds_conn_drop(ic->conn);
	spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
}

/*
 * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
 * from interrupt context so we push freing off into a work struct in krdsd.
 */
static void rds_ib_dev_free(struct work_struct *work)
{
	struct rds_ib_ipaddr *i_ipaddr, *i_next;
	struct rds_ib_device *rds_ibdev = container_of(work,
					struct rds_ib_device, free_work);

	if (rds_ibdev->mr_pool)
		rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
	if (rds_ibdev->mr)
		ib_dereg_mr(rds_ibdev->mr);
	if (rds_ibdev->pd)
		ib_dealloc_pd(rds_ibdev->pd);

	list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
		list_del(&i_ipaddr->list);
		kfree(i_ipaddr);
	}

	kfree(rds_ibdev);
}

void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
{
	BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
	if (atomic_dec_and_test(&rds_ibdev->refcount))
		queue_work(rds_wq, &rds_ibdev->free_work);
}

void rds_ib_add_one(struct ib_device *device)
{
	struct rds_ib_device *rds_ibdev;
	struct ib_device_attr *dev_attr;

	/* Only handle IB (no iWARP) devices */
	if (device->node_type != RDMA_NODE_IB_CA)
		return;

	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
	if (!dev_attr)
		return;

	if (ib_query_device(device, dev_attr)) {
		rdsdebug("Query device failed for %s\n", device->name);
		goto free_attr;
	}

	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
				 ibdev_to_node(device));
	if (!rds_ibdev)
		goto free_attr;

	spin_lock_init(&rds_ibdev->spinlock);
	atomic_set(&rds_ibdev->refcount, 1);
	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);

	rds_ibdev->max_wrs = dev_attr->max_qp_wr;
	rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);

	rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
	rds_ibdev->max_fmrs = dev_attr->max_fmr ?
			min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
			fmr_pool_size;

	rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
	rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;

	rds_ibdev->dev = device;
	rds_ibdev->pd = ib_alloc_pd(device);
	if (IS_ERR(rds_ibdev->pd)) {
		rds_ibdev->pd = NULL;
		goto put_dev;
	}

	rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE);
	if (IS_ERR(rds_ibdev->mr)) {
		rds_ibdev->mr = NULL;
		goto put_dev;
	}

	rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
	if (IS_ERR(rds_ibdev->mr_pool)) {
		rds_ibdev->mr_pool = NULL;
		goto put_dev;
	}

	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
	INIT_LIST_HEAD(&rds_ibdev->conn_list);
	list_add_tail(&rds_ibdev->list, &rds_ib_devices);
	atomic_inc(&rds_ibdev->refcount);

	ib_set_client_data(device, &rds_ib_client, rds_ibdev);
	atomic_inc(&rds_ibdev->refcount);

	rds_ib_nodev_connect();

put_dev:
	rds_ib_dev_put(rds_ibdev);
free_attr:
	kfree(dev_attr);
}

/*
 * New connections use this to find the device to associate with the
 * connection.  It's not in the fast path so we're not concerned about the
 * performance of the IB call.  (As of this writing, it uses an interrupt
 * blocking spinlock to serialize walking a per-device list of all registered
 * clients.)
 *
 * RCU is used to handle incoming connections racing with device teardown.
 * Rather than use a lock to serialize removal from the client_data and
 * getting a new reference, we use an RCU grace period.  The destruction
 * path removes the device from client_data and then waits for all RCU
 * readers to finish.
 *
 * A new connection can get NULL from this if its arriving on a
 * device that is in the process of being removed.
 */
struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
{
	struct rds_ib_device *rds_ibdev;

	rcu_read_lock();
	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
	if (rds_ibdev)
		atomic_inc(&rds_ibdev->refcount);
	rcu_read_unlock();
	return rds_ibdev;
}

/*
 * The IB stack is letting us know that a device is going away.  This can
 * happen if the underlying HCA driver is removed or if PCI hotplug is removing
 * the pci function, for example.
 *
 * This can be called at any time and can be racing with any other RDS path.
 */
void rds_ib_remove_one(struct ib_device *device)
{
	struct rds_ib_device *rds_ibdev;

	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
	if (!rds_ibdev)
		return;

	rds_ib_dev_shutdown(rds_ibdev);

	/*
	 * prevent future connection attempts from getting a reference to this
	 * device and wait for currently racing connection attempts to finish
	 * getting their reference
	 */
	ib_set_client_data(device, &rds_ib_client, NULL);
	synchronize_rcu();
	rds_ib_dev_put(rds_ibdev);

	list_del(&rds_ibdev->list);
	rds_ib_dev_put(rds_ibdev);
}

struct ib_client rds_ib_client = {
	.name   = "rds_ib",
	.add    = rds_ib_add_one,
	.remove = rds_ib_remove_one
};

static int rds_ib_conn_info_visitor(struct rds_connection *conn,
				    void *buffer)
{
	struct rds_info_rdma_connection *iinfo = buffer;
	struct rds_ib_connection *ic;

	/* We will only ever look at IB transports */
	if (conn->c_trans != &rds_ib_transport)
		return 0;

	iinfo->src_addr = conn->c_laddr;
	iinfo->dst_addr = conn->c_faddr;

	memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
	memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
	if (rds_conn_state(conn) == RDS_CONN_UP) {
		struct rds_ib_device *rds_ibdev;
		struct rdma_dev_addr *dev_addr;

		ic = conn->c_transport_data;
		dev_addr = &ic->i_cm_id->route.addr.dev_addr;

		rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
		rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);

		rds_ibdev = ic->rds_ibdev;
		iinfo->max_send_wr = ic->i_send_ring.w_nr;
		iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
		iinfo->max_send_sge = rds_ibdev->max_sge;
		rds_ib_get_mr_info(rds_ibdev, iinfo);
	}
	return 1;
}

static void rds_ib_ic_info(struct socket *sock, unsigned int len,
			   struct rds_info_iterator *iter,
			   struct rds_info_lengths *lens)
{
	rds_for_each_conn_info(sock, len, iter, lens,
				rds_ib_conn_info_visitor,
				sizeof(struct rds_info_rdma_connection));
}


/*
 * Early RDS/IB was built to only bind to an address if there is an IPoIB
 * device with that address set.
 *
 * If it were me, I'd advocate for something more flexible.  Sending and
 * receiving should be device-agnostic.  Transports would try and maintain
 * connections between peers who have messages queued.  Userspace would be
 * allowed to influence which paths have priority.  We could call userspace
 * asserting this policy "routing".
 */
static int rds_ib_laddr_check(__be32 addr)
{
	int ret;
	struct rdma_cm_id *cm_id;
	struct sockaddr_in sin;

	/* Create a CMA ID and try to bind it. This catches both
	 * IB and iWARP capable NICs.
	 */
	cm_id = rdma_create_id(NULL, NULL, RDMA_PS_TCP);
	if (IS_ERR(cm_id))
		return PTR_ERR(cm_id);

	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = addr;

	/* rdma_bind_addr will only succeed for IB & iWARP devices */
	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
	/* due to this, we will claim to support iWARP devices unless we
	   check node_type. */
	if (ret || cm_id->device->node_type != RDMA_NODE_IB_CA)
		ret = -EADDRNOTAVAIL;

	rdsdebug("addr %pI4 ret %d node type %d\n",
		&addr, ret,
		cm_id->device ? cm_id->device->node_type : -1);

	rdma_destroy_id(cm_id);

	return ret;
}

static void rds_ib_unregister_client(void)
{
	ib_unregister_client(&rds_ib_client);
	/* wait for rds_ib_dev_free() to complete */
	flush_workqueue(rds_wq);
}

void rds_ib_exit(void)
{
	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
	rds_ib_unregister_client();
	rds_ib_destroy_nodev_conns();
	rds_ib_sysctl_exit();
	rds_ib_recv_exit();
	rds_trans_unregister(&rds_ib_transport);
}

struct rds_transport rds_ib_transport = {
	.laddr_check		= rds_ib_laddr_check,
	.xmit_complete		= rds_ib_xmit_complete,
	.xmit			= rds_ib_xmit,
	.xmit_rdma		= rds_ib_xmit_rdma,
	.xmit_atomic		= rds_ib_xmit_atomic,
	.recv			= rds_ib_recv,
	.conn_alloc		= rds_ib_conn_alloc,
	.conn_free		= rds_ib_conn_free,
	.conn_connect		= rds_ib_conn_connect,
	.conn_shutdown		= rds_ib_conn_shutdown,
	.inc_copy_to_user	= rds_ib_inc_copy_to_user,
	.inc_free		= rds_ib_inc_free,
	.cm_initiate_connect	= rds_ib_cm_initiate_connect,
	.cm_handle_connect	= rds_ib_cm_handle_connect,
	.cm_connect_complete	= rds_ib_cm_connect_complete,
	.stats_info_copy	= rds_ib_stats_info_copy,
	.exit			= rds_ib_exit,
	.get_mr			= rds_ib_get_mr,
	.sync_mr		= rds_ib_sync_mr,
	.free_mr		= rds_ib_free_mr,
	.flush_mrs		= rds_ib_flush_mrs,
	.t_owner		= THIS_MODULE,
	.t_name			= "infiniband",
	.t_type			= RDS_TRANS_IB
};

int __init rds_ib_init(void)
{
	int ret;

	INIT_LIST_HEAD(&rds_ib_devices);

	ret = ib_register_client(&rds_ib_client);
	if (ret)
		goto out;

	ret = rds_ib_sysctl_init();
	if (ret)
		goto out_ibreg;

	ret = rds_ib_recv_init();
	if (ret)
		goto out_sysctl;

	ret = rds_trans_register(&rds_ib_transport);
	if (ret)
		goto out_recv;

	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);

	goto out;

out_recv:
	rds_ib_recv_exit();
out_sysctl:
	rds_ib_sysctl_exit();
out_ibreg:
	rds_ib_unregister_client();
out:
	return ret;
}

MODULE_LICENSE("GPL");
Commit	Line	Data
ec16227e AG	1	/*
	2	* Copyright (c) 2006 Oracle. All rights reserved.
	3	*
	4	* This software is available to you under a choice of one of two
	5	* licenses. You may choose to be licensed under the terms of the GNU
	6	* General Public License (GPL) Version 2, available from the file
	7	* COPYING in the main directory of this source tree, or the
	8	* OpenIB.org BSD license below:
	9	*
	10	* Redistribution and use in source and binary forms, with or
	11	* without modification, are permitted provided that the following
	12	* conditions are met:
	13	*
	14	* - Redistributions of source code must retain the above
	15	* copyright notice, this list of conditions and the following
	16	* disclaimer.
	17	*
	18	* - Redistributions in binary form must reproduce the above
	19	* copyright notice, this list of conditions and the following
	20	* disclaimer in the documentation and/or other materials
	21	* provided with the distribution.
	22	*
	23	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	24	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	25	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	26	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	27	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	28	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	29	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	30	* SOFTWARE.
	31	*
	32	*/
	33	#include <linux/kernel.h>
	34	#include <linux/in.h>
	35	#include <linux/if.h>
	36	#include <linux/netdevice.h>
	37	#include <linux/inetdevice.h>
	38	#include <linux/if_arp.h>
	39	#include <linux/delay.h>
5a0e3ad6	40	#include <linux/slab.h>
ec16227e AG	41
	42	#include "rds.h"
	43	#include "ib.h"
	44
	45	unsigned int fmr_pool_size = RDS_FMR_POOL_SIZE;
	46	unsigned int fmr_message_size = RDS_FMR_SIZE + 1; /* +1 allows for unaligned MRs */
3ba23ade	47	unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
ec16227e AG	48
	49	module_param(fmr_pool_size, int, 0444);
	50	MODULE_PARM_DESC(fmr_pool_size, " Max number of fmr per HCA");
	51	module_param(fmr_message_size, int, 0444);
	52	MODULE_PARM_DESC(fmr_message_size, " Max size of a RDMA transfer");
3ba23ade AG	53	module_param(rds_ib_retry_count, int, 0444);
3ba23ade AG	54	MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
ec16227e AG	55
	56	struct list_head rds_ib_devices;
	57
745cbcca	58	/* NOTE: if also grabbing ibdev lock, grab this first */
ec16227e AG	59	DEFINE_SPINLOCK(ib_nodev_conns_lock);
	60	LIST_HEAD(ib_nodev_conns);
	61
fc19de38 ZB	62	void rds_ib_nodev_connect(void)
	63	{
	64	struct rds_ib_connection *ic;
	65
	66	spin_lock(&ib_nodev_conns_lock);
	67	list_for_each_entry(ic, &ib_nodev_conns, ib_node)
	68	rds_conn_connect_if_down(ic->conn);
	69	spin_unlock(&ib_nodev_conns_lock);
	70	}
	71
	72	void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
	73	{
	74	struct rds_ib_connection *ic;
	75	unsigned long flags;
	76
	77	spin_lock_irqsave(&rds_ibdev->spinlock, flags);
	78	list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
	79	rds_conn_drop(ic->conn);
	80	spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
	81	}
	82
3e0249f9 ZB	83	/*
	84	* rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
	85	* from interrupt context so we push freing off into a work struct in krdsd.
	86	*/
	87	static void rds_ib_dev_free(struct work_struct *work)
	88	{
	89	struct rds_ib_ipaddr i_ipaddr, i_next;
	90	struct rds_ib_device *rds_ibdev = container_of(work,
	91	struct rds_ib_device, free_work);
	92
	93	if (rds_ibdev->mr_pool)
	94	rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
	95	if (rds_ibdev->mr)
	96	ib_dereg_mr(rds_ibdev->mr);
	97	if (rds_ibdev->pd)
	98	ib_dealloc_pd(rds_ibdev->pd);
	99
	100	list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
	101	list_del(&i_ipaddr->list);
	102	kfree(i_ipaddr);
	103	}
	104
	105	kfree(rds_ibdev);
	106	}
	107
	108	void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
	109	{
	110	BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
	111	if (atomic_dec_and_test(&rds_ibdev->refcount))
	112	queue_work(rds_wq, &rds_ibdev->free_work);
	113	}
	114
ec16227e AG	115	void rds_ib_add_one(struct ib_device *device)
	116	{
	117	struct rds_ib_device *rds_ibdev;
	118	struct ib_device_attr *dev_attr;
	119
	120	/* Only handle IB (no iWARP) devices */
	121	if (device->node_type != RDMA_NODE_IB_CA)
	122	return;
	123
	124	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
	125	if (!dev_attr)
	126	return;
	127
	128	if (ib_query_device(device, dev_attr)) {
	129	rdsdebug("Query device failed for %s\n", device->name);
	130	goto free_attr;
	131	}
	132
3e0249f9 ZB	133	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
3e0249f9 ZB	134	ibdev_to_node(device));
ec16227e AG	135	if (!rds_ibdev)
	136	goto free_attr;
	137
	138	spin_lock_init(&rds_ibdev->spinlock);
3e0249f9 ZB	139	atomic_set(&rds_ibdev->refcount, 1);
3e0249f9 ZB	140	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
ec16227e AG	141
	142	rds_ibdev->max_wrs = dev_attr->max_qp_wr;
	143	rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
	144
ec16227e AG	145	rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
	146	rds_ibdev->max_fmrs = dev_attr->max_fmr ?
	147	min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
	148	fmr_pool_size;
	149
40589e74 AG	150	rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
	151	rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
	152
ec16227e AG	153	rds_ibdev->dev = device;
ec16227e AG	154	rds_ibdev->pd = ib_alloc_pd(device);
3e0249f9 ZB	155	if (IS_ERR(rds_ibdev->pd)) {
	156	rds_ibdev->pd = NULL;
	157	goto put_dev;
	158	}
ec16227e	159
3e0249f9 ZB	160	rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE);
	161	if (IS_ERR(rds_ibdev->mr)) {
	162	rds_ibdev->mr = NULL;
	163	goto put_dev;
	164	}
ec16227e AG	165
	166	rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
	167	if (IS_ERR(rds_ibdev->mr_pool)) {
	168	rds_ibdev->mr_pool = NULL;
3e0249f9	169	goto put_dev;
ec16227e AG	170	}
	171
	172	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
	173	INIT_LIST_HEAD(&rds_ibdev->conn_list);
	174	list_add_tail(&rds_ibdev->list, &rds_ib_devices);
3e0249f9	175	atomic_inc(&rds_ibdev->refcount);
ec16227e AG	176
ec16227e AG	177	ib_set_client_data(device, &rds_ib_client, rds_ibdev);
3e0249f9	178	atomic_inc(&rds_ibdev->refcount);
ec16227e	179
fc19de38 ZB	180	rds_ib_nodev_connect();
fc19de38 ZB	181
3e0249f9 ZB	182	put_dev:
3e0249f9 ZB	183	rds_ib_dev_put(rds_ibdev);
ec16227e AG	184	free_attr:
	185	kfree(dev_attr);
	186	}
	187
3e0249f9 ZB	188	/*
	189	* New connections use this to find the device to associate with the
	190	* connection. It's not in the fast path so we're not concerned about the
	191	* performance of the IB call. (As of this writing, it uses an interrupt
	192	* blocking spinlock to serialize walking a per-device list of all registered
	193	* clients.)
	194	*
	195	* RCU is used to handle incoming connections racing with device teardown.
	196	* Rather than use a lock to serialize removal from the client_data and
	197	* getting a new reference, we use an RCU grace period. The destruction
	198	* path removes the device from client_data and then waits for all RCU
	199	* readers to finish.
	200	*
	201	* A new connection can get NULL from this if its arriving on a
	202	* device that is in the process of being removed.
	203	*/
	204	struct rds_ib_device rds_ib_get_client_data(struct ib_device device)
	205	{
	206	struct rds_ib_device *rds_ibdev;
	207
	208	rcu_read_lock();
	209	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
	210	if (rds_ibdev)
	211	atomic_inc(&rds_ibdev->refcount);
	212	rcu_read_unlock();
	213	return rds_ibdev;
	214	}
	215
	216	/*
	217	* The IB stack is letting us know that a device is going away. This can
	218	* happen if the underlying HCA driver is removed or if PCI hotplug is removing
	219	* the pci function, for example.
	220	*
	221	* This can be called at any time and can be racing with any other RDS path.
	222	*/
ec16227e AG	223	void rds_ib_remove_one(struct ib_device *device)
	224	{
	225	struct rds_ib_device *rds_ibdev;
ec16227e AG	226
	227	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
	228	if (!rds_ibdev)
	229	return;
	230
fc19de38	231	rds_ib_dev_shutdown(rds_ibdev);
ec16227e	232
3e0249f9 ZB	233	/*
	234	* prevent future connection attempts from getting a reference to this
	235	* device and wait for currently racing connection attempts to finish
	236	* getting their reference
	237	*/
	238	ib_set_client_data(device, &rds_ib_client, NULL);
	239	synchronize_rcu();
	240	rds_ib_dev_put(rds_ibdev);
ec16227e AG	241
ec16227e AG	242	list_del(&rds_ibdev->list);
3e0249f9	243	rds_ib_dev_put(rds_ibdev);
ec16227e AG	244	}
	245
	246	struct ib_client rds_ib_client = {
	247	.name = "rds_ib",
	248	.add = rds_ib_add_one,
	249	.remove = rds_ib_remove_one
	250	};
	251
	252	static int rds_ib_conn_info_visitor(struct rds_connection *conn,
	253	void *buffer)
	254	{
	255	struct rds_info_rdma_connection *iinfo = buffer;
	256	struct rds_ib_connection *ic;
	257
	258	/* We will only ever look at IB transports */
	259	if (conn->c_trans != &rds_ib_transport)
	260	return 0;
	261
	262	iinfo->src_addr = conn->c_laddr;
	263	iinfo->dst_addr = conn->c_faddr;
	264
	265	memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
	266	memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
	267	if (rds_conn_state(conn) == RDS_CONN_UP) {
	268	struct rds_ib_device *rds_ibdev;
	269	struct rdma_dev_addr *dev_addr;
	270
	271	ic = conn->c_transport_data;
	272	dev_addr = &ic->i_cm_id->route.addr.dev_addr;
	273
6f8372b6 SH	274	rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
6f8372b6 SH	275	rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
ec16227e	276
3e0249f9	277	rds_ibdev = ic->rds_ibdev;
ec16227e AG	278	iinfo->max_send_wr = ic->i_send_ring.w_nr;
	279	iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
	280	iinfo->max_send_sge = rds_ibdev->max_sge;
	281	rds_ib_get_mr_info(rds_ibdev, iinfo);
	282	}
	283	return 1;
	284	}
	285
	286	static void rds_ib_ic_info(struct socket *sock, unsigned int len,
	287	struct rds_info_iterator *iter,
	288	struct rds_info_lengths *lens)
	289	{
	290	rds_for_each_conn_info(sock, len, iter, lens,
	291	rds_ib_conn_info_visitor,
	292	sizeof(struct rds_info_rdma_connection));
	293	}
	294
	295
	296	/*
	297	* Early RDS/IB was built to only bind to an address if there is an IPoIB
	298	* device with that address set.
	299	*
	300	* If it were me, I'd advocate for something more flexible. Sending and
	301	* receiving should be device-agnostic. Transports would try and maintain
	302	* connections between peers who have messages queued. Userspace would be
	303	* allowed to influence which paths have priority. We could call userspace
	304	* asserting this policy "routing".
	305	*/
	306	static int rds_ib_laddr_check(__be32 addr)
	307	{
	308	int ret;
	309	struct rdma_cm_id *cm_id;
	310	struct sockaddr_in sin;
	311
	312	/* Create a CMA ID and try to bind it. This catches both
	313	* IB and iWARP capable NICs.
	314	*/
	315	cm_id = rdma_create_id(NULL, NULL, RDMA_PS_TCP);
94713bab DC	316	if (IS_ERR(cm_id))
94713bab DC	317	return PTR_ERR(cm_id);
ec16227e AG	318
	319	memset(&sin, 0, sizeof(sin));
	320	sin.sin_family = AF_INET;
	321	sin.sin_addr.s_addr = addr;
	322
	323	/* rdma_bind_addr will only succeed for IB & iWARP devices */
	324	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
	325	/* due to this, we will claim to support iWARP devices unless we
	326	check node_type. */
	327	if (ret \|\| cm_id->device->node_type != RDMA_NODE_IB_CA)
	328	ret = -EADDRNOTAVAIL;
	329
	330	rdsdebug("addr %pI4 ret %d node type %d\n",
	331	&addr, ret,
	332	cm_id->device ? cm_id->device->node_type : -1);
	333
	334	rdma_destroy_id(cm_id);
	335
	336	return ret;
	337	}
	338
24fa163a ZB	339	static void rds_ib_unregister_client(void)
	340	{
	341	ib_unregister_client(&rds_ib_client);
	342	/* wait for rds_ib_dev_free() to complete */
	343	flush_workqueue(rds_wq);
	344	}
	345
ec16227e AG	346	void rds_ib_exit(void)
	347	{
	348	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
24fa163a	349	rds_ib_unregister_client();
8aeb1ba6	350	rds_ib_destroy_nodev_conns();
ec16227e AG	351	rds_ib_sysctl_exit();
	352	rds_ib_recv_exit();
	353	rds_trans_unregister(&rds_ib_transport);
	354	}
	355
	356	struct rds_transport rds_ib_transport = {
	357	.laddr_check = rds_ib_laddr_check,
	358	.xmit_complete = rds_ib_xmit_complete,
	359	.xmit = rds_ib_xmit,
ec16227e	360	.xmit_rdma = rds_ib_xmit_rdma,
15133f6e	361	.xmit_atomic = rds_ib_xmit_atomic,
ec16227e AG	362	.recv = rds_ib_recv,
	363	.conn_alloc = rds_ib_conn_alloc,
	364	.conn_free = rds_ib_conn_free,
	365	.conn_connect = rds_ib_conn_connect,
	366	.conn_shutdown = rds_ib_conn_shutdown,
	367	.inc_copy_to_user = rds_ib_inc_copy_to_user,
ec16227e AG	368	.inc_free = rds_ib_inc_free,
	369	.cm_initiate_connect = rds_ib_cm_initiate_connect,
	370	.cm_handle_connect = rds_ib_cm_handle_connect,
	371	.cm_connect_complete = rds_ib_cm_connect_complete,
	372	.stats_info_copy = rds_ib_stats_info_copy,
	373	.exit = rds_ib_exit,
	374	.get_mr = rds_ib_get_mr,
	375	.sync_mr = rds_ib_sync_mr,
	376	.free_mr = rds_ib_free_mr,
	377	.flush_mrs = rds_ib_flush_mrs,
	378	.t_owner = THIS_MODULE,
	379	.t_name = "infiniband",
335776bd	380	.t_type = RDS_TRANS_IB
ec16227e AG	381	};
	382
	383	int __init rds_ib_init(void)
	384	{
	385	int ret;
	386
	387	INIT_LIST_HEAD(&rds_ib_devices);
	388
	389	ret = ib_register_client(&rds_ib_client);
	390	if (ret)
	391	goto out;
	392
	393	ret = rds_ib_sysctl_init();
	394	if (ret)
	395	goto out_ibreg;
	396
	397	ret = rds_ib_recv_init();
	398	if (ret)
	399	goto out_sysctl;
	400
	401	ret = rds_trans_register(&rds_ib_transport);
	402	if (ret)
	403	goto out_recv;
	404
	405	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
	406
	407	goto out;
	408
	409	out_recv:
	410	rds_ib_recv_exit();
	411	out_sysctl:
	412	rds_ib_sysctl_exit();
	413	out_ibreg:
24fa163a	414	rds_ib_unregister_client();
ec16227e AG	415	out:
	416	return ret;
	417	}
	418
	419	MODULE_LICENSE("GPL");
	420