RDS: Add iWARP support

Support for iWARP NICs is implemented as a separate
RDS transport from IB. The code, however, is very
similar to IB (it was forked, basically.) so let's keep
it in one changeset.

The reason for this duplicationis that despite its similarity
to IB, there are a number of places where it has different
semantics. iwarp zcopy support is still under development,
and giving it its own sandbox ensures that IB code isn't
disrupted while iwarp changes. Over time these transports
will re-converge.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 333 insertions, 0 deletions

diff --git a/net/rds/iw.c b/net/rds/iw.c
new file mode 100644
index 00000000000..1b56905c4c0
--- /dev/null
+++ b/net/rds/iw.c
@@ -0,0 +1,333 @@
+/*
+ * 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 "rds.h"
+#include "iw.h"
+
+unsigned int fastreg_pool_size = RDS_FASTREG_POOL_SIZE;
+unsigned int fastreg_message_size = RDS_FASTREG_SIZE + 1; /* +1 allows for unaligned MRs */
+
+module_param(fastreg_pool_size, int, 0444);
+MODULE_PARM_DESC(fastreg_pool_size, " Max number of fastreg MRs per device");
+module_param(fastreg_message_size, int, 0444);
+MODULE_PARM_DESC(fastreg_message_size, " Max size of a RDMA transfer (fastreg MRs)");
+
+struct list_head rds_iw_devices;
+
+DEFINE_SPINLOCK(iw_nodev_conns_lock);
+LIST_HEAD(iw_nodev_conns);
+
+void rds_iw_add_one(struct ib_device *device)
+{
+	struct rds_iw_device *rds_iwdev;
+	struct ib_device_attr *dev_attr;
+
+	/* Only handle iwarp devices */
+	if (device->node_type != RDMA_NODE_RNIC)
+		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_iwdev = kmalloc(sizeof *rds_iwdev, GFP_KERNEL);
+	if (!rds_iwdev)
+		goto free_attr;
+
+	spin_lock_init(&rds_iwdev->spinlock);
+
+	rds_iwdev->dma_local_lkey = !!(dev_attr->device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY);
+	rds_iwdev->max_wrs = dev_attr->max_qp_wr;
+	rds_iwdev->max_sge = min(dev_attr->max_sge, RDS_IW_MAX_SGE);
+
+	rds_iwdev->page_shift = max(PAGE_SHIFT, ffs(dev_attr->page_size_cap) - 1);
+
+	rds_iwdev->dev = device;
+	rds_iwdev->pd = ib_alloc_pd(device);
+	if (IS_ERR(rds_iwdev->pd))
+		goto free_dev;
+
+	if (!rds_iwdev->dma_local_lkey) {
+		if (device->node_type != RDMA_NODE_RNIC) {
+			rds_iwdev->mr = ib_get_dma_mr(rds_iwdev->pd,
+						IB_ACCESS_LOCAL_WRITE);
+		} else {
+			rds_iwdev->mr = ib_get_dma_mr(rds_iwdev->pd,
+						IB_ACCESS_REMOTE_READ |
+						IB_ACCESS_REMOTE_WRITE |
+						IB_ACCESS_LOCAL_WRITE);
+		}
+		if (IS_ERR(rds_iwdev->mr))
+			goto err_pd;
+	} else
+		rds_iwdev->mr = NULL;
+
+	rds_iwdev->mr_pool = rds_iw_create_mr_pool(rds_iwdev);
+	if (IS_ERR(rds_iwdev->mr_pool)) {
+		rds_iwdev->mr_pool = NULL;
+		goto err_mr;
+	}
+
+	INIT_LIST_HEAD(&rds_iwdev->cm_id_list);
+	INIT_LIST_HEAD(&rds_iwdev->conn_list);
+	list_add_tail(&rds_iwdev->list, &rds_iw_devices);
+
+	ib_set_client_data(device, &rds_iw_client, rds_iwdev);
+
+	goto free_attr;
+
+err_mr:
+	if (rds_iwdev->mr)
+		ib_dereg_mr(rds_iwdev->mr);
+err_pd:
+	ib_dealloc_pd(rds_iwdev->pd);
+free_dev:
+	kfree(rds_iwdev);
+free_attr:
+	kfree(dev_attr);
+}
+
+void rds_iw_remove_one(struct ib_device *device)
+{
+	struct rds_iw_device *rds_iwdev;
+	struct rds_iw_cm_id *i_cm_id, *next;
+
+	rds_iwdev = ib_get_client_data(device, &rds_iw_client);
+	if (!rds_iwdev)
+		return;
+
+	spin_lock_irq(&rds_iwdev->spinlock);
+	list_for_each_entry_safe(i_cm_id, next, &rds_iwdev->cm_id_list, list) {
+		list_del(&i_cm_id->list);
+		kfree(i_cm_id);
+	}
+	spin_unlock_irq(&rds_iwdev->spinlock);
+
+	rds_iw_remove_conns(rds_iwdev);
+
+	if (rds_iwdev->mr_pool)
+		rds_iw_destroy_mr_pool(rds_iwdev->mr_pool);
+
+	if (rds_iwdev->mr)
+		ib_dereg_mr(rds_iwdev->mr);
+
+	while (ib_dealloc_pd(rds_iwdev->pd)) {
+		rdsdebug("Failed to dealloc pd %p\n", rds_iwdev->pd);
+		msleep(1);
+	}
+
+	list_del(&rds_iwdev->list);
+	kfree(rds_iwdev);
+}
+
+struct ib_client rds_iw_client = {
+	.name   = "rds_iw",
+	.add    = rds_iw_add_one,
+	.remove = rds_iw_remove_one
+};
+
+static int rds_iw_conn_info_visitor(struct rds_connection *conn,
+				    void *buffer)
+{
+	struct rds_info_rdma_connection *iinfo = buffer;
+	struct rds_iw_connection *ic;
+
+	/* We will only ever look at IB transports */
+	if (conn->c_trans != &rds_iw_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_iw_device *rds_iwdev;
+		struct rdma_dev_addr *dev_addr;
+
+		ic = conn->c_transport_data;
+		dev_addr = &ic->i_cm_id->route.addr.dev_addr;
+
+		ib_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
+		ib_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
+
+		rds_iwdev = ib_get_client_data(ic->i_cm_id->device, &rds_iw_client);
+		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_iwdev->max_sge;
+		rds_iw_get_mr_info(rds_iwdev, iinfo);
+	}
+	return 1;
+}
+
+static void rds_iw_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_iw_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_iw_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 (!cm_id)
+		return -EADDRNOTAVAIL;
+
+	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 IB devices unless we
+	   check node_type. */
+	if (ret || cm_id->device->node_type != RDMA_NODE_RNIC)
+		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;
+}
+
+void rds_iw_exit(void)
+{
+	rds_info_deregister_func(RDS_INFO_IWARP_CONNECTIONS, rds_iw_ic_info);
+	rds_iw_remove_nodev_conns();
+	ib_unregister_client(&rds_iw_client);
+	rds_iw_sysctl_exit();
+	rds_iw_recv_exit();
+	rds_trans_unregister(&rds_iw_transport);
+}
+
+struct rds_transport rds_iw_transport = {
+	.laddr_check		= rds_iw_laddr_check,
+	.xmit_complete		= rds_iw_xmit_complete,
+	.xmit			= rds_iw_xmit,
+	.xmit_cong_map		= NULL,
+	.xmit_rdma		= rds_iw_xmit_rdma,
+	.recv			= rds_iw_recv,
+	.conn_alloc		= rds_iw_conn_alloc,
+	.conn_free		= rds_iw_conn_free,
+	.conn_connect		= rds_iw_conn_connect,
+	.conn_shutdown		= rds_iw_conn_shutdown,
+	.inc_copy_to_user	= rds_iw_inc_copy_to_user,
+	.inc_purge		= rds_iw_inc_purge,
+	.inc_free		= rds_iw_inc_free,
+	.cm_initiate_connect	= rds_iw_cm_initiate_connect,
+	.cm_handle_connect	= rds_iw_cm_handle_connect,
+	.cm_connect_complete	= rds_iw_cm_connect_complete,
+	.stats_info_copy	= rds_iw_stats_info_copy,
+	.exit			= rds_iw_exit,
+	.get_mr			= rds_iw_get_mr,
+	.sync_mr		= rds_iw_sync_mr,
+	.free_mr		= rds_iw_free_mr,
+	.flush_mrs		= rds_iw_flush_mrs,
+	.t_owner		= THIS_MODULE,
+	.t_name			= "iwarp",
+	.t_prefer_loopback	= 1,
+};
+
+int __init rds_iw_init(void)
+{
+	int ret;
+
+	INIT_LIST_HEAD(&rds_iw_devices);
+
+	ret = ib_register_client(&rds_iw_client);
+	if (ret)
+		goto out;
+
+	ret = rds_iw_sysctl_init();
+	if (ret)
+		goto out_ibreg;
+
+	ret = rds_iw_recv_init();
+	if (ret)
+		goto out_sysctl;
+
+	ret = rds_trans_register(&rds_iw_transport);
+	if (ret)
+		goto out_recv;
+
+	rds_info_register_func(RDS_INFO_IWARP_CONNECTIONS, rds_iw_ic_info);
+
+	goto out;
+
+out_recv:
+	rds_iw_recv_exit();
+out_sysctl:
+	rds_iw_sysctl_exit();
+out_ibreg:
+	ib_unregister_client(&rds_iw_client);
+out:
+	return ret;
+}
+
+MODULE_LICENSE("GPL");
+