v4.19.13 snapshot.
diff --git a/net/rds/ib.c b/net/rds/ib.c
new file mode 100644
index 0000000..eba75c1
--- /dev/null
+++ b/net/rds/ib.c
@@ -0,0 +1,586 @@
+/*
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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 <linux/module.h>
+#include <net/addrconf.h>
+
+#include "rds_single_path.h"
+#include "rds.h"
+#include "ib.h"
+#include "ib_mr.h"
+
+static unsigned int rds_ib_mr_1m_pool_size = RDS_MR_1M_POOL_SIZE;
+static unsigned int rds_ib_mr_8k_pool_size = RDS_MR_8K_POOL_SIZE;
+unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
+static atomic_t rds_ib_unloading;
+
+module_param(rds_ib_mr_1m_pool_size, int, 0444);
+MODULE_PARM_DESC(rds_ib_mr_1m_pool_size, " Max number of 1M mr per HCA");
+module_param(rds_ib_mr_8k_pool_size, int, 0444);
+MODULE_PARM_DESC(rds_ib_mr_8k_pool_size, " Max number of 8K mr per HCA");
+module_param(rds_ib_retry_count, int, 0444);
+MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
+
+/*
+ * we have a clumsy combination of RCU and a rwsem protecting this list
+ * because it is used both in the get_mr fast path and while blocking in
+ * the FMR flushing path.
+ */
+DECLARE_RWSEM(rds_ib_devices_lock);
+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);
+
+static 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);
+}
+
+static 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_8k_pool)
+		rds_ib_destroy_mr_pool(rds_ibdev->mr_8k_pool);
+	if (rds_ibdev->mr_1m_pool)
+		rds_ib_destroy_mr_pool(rds_ibdev->mr_1m_pool);
+	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->vector_load);
+
+	kfree(rds_ibdev);
+}
+
+void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
+{
+	BUG_ON(refcount_read(&rds_ibdev->refcount) == 0);
+	if (refcount_dec_and_test(&rds_ibdev->refcount))
+		queue_work(rds_wq, &rds_ibdev->free_work);
+}
+
+static void rds_ib_add_one(struct ib_device *device)
+{
+	struct rds_ib_device *rds_ibdev;
+	bool has_fr, has_fmr;
+
+	/* Only handle IB (no iWARP) devices */
+	if (device->node_type != RDMA_NODE_IB_CA)
+		return;
+
+	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
+				 ibdev_to_node(device));
+	if (!rds_ibdev)
+		return;
+
+	spin_lock_init(&rds_ibdev->spinlock);
+	refcount_set(&rds_ibdev->refcount, 1);
+	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
+
+	rds_ibdev->max_wrs = device->attrs.max_qp_wr;
+	rds_ibdev->max_sge = min(device->attrs.max_send_sge, RDS_IB_MAX_SGE);
+
+	has_fr = (device->attrs.device_cap_flags &
+		  IB_DEVICE_MEM_MGT_EXTENSIONS);
+	has_fmr = (device->alloc_fmr && device->dealloc_fmr &&
+		   device->map_phys_fmr && device->unmap_fmr);
+	rds_ibdev->use_fastreg = (has_fr && !has_fmr);
+
+	rds_ibdev->fmr_max_remaps = device->attrs.max_map_per_fmr?: 32;
+	rds_ibdev->max_1m_mrs = device->attrs.max_mr ?
+		min_t(unsigned int, (device->attrs.max_mr / 2),
+		      rds_ib_mr_1m_pool_size) : rds_ib_mr_1m_pool_size;
+
+	rds_ibdev->max_8k_mrs = device->attrs.max_mr ?
+		min_t(unsigned int, ((device->attrs.max_mr / 2) * RDS_MR_8K_SCALE),
+		      rds_ib_mr_8k_pool_size) : rds_ib_mr_8k_pool_size;
+
+	rds_ibdev->max_initiator_depth = device->attrs.max_qp_init_rd_atom;
+	rds_ibdev->max_responder_resources = device->attrs.max_qp_rd_atom;
+
+	rds_ibdev->vector_load = kcalloc(device->num_comp_vectors,
+					 sizeof(int),
+					 GFP_KERNEL);
+	if (!rds_ibdev->vector_load) {
+		pr_err("RDS/IB: %s failed to allocate vector memory\n",
+			__func__);
+		goto put_dev;
+	}
+
+	rds_ibdev->dev = device;
+	rds_ibdev->pd = ib_alloc_pd(device, 0);
+	if (IS_ERR(rds_ibdev->pd)) {
+		rds_ibdev->pd = NULL;
+		goto put_dev;
+	}
+
+	rds_ibdev->mr_1m_pool =
+		rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
+	if (IS_ERR(rds_ibdev->mr_1m_pool)) {
+		rds_ibdev->mr_1m_pool = NULL;
+		goto put_dev;
+	}
+
+	rds_ibdev->mr_8k_pool =
+		rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
+	if (IS_ERR(rds_ibdev->mr_8k_pool)) {
+		rds_ibdev->mr_8k_pool = NULL;
+		goto put_dev;
+	}
+
+	rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, fmr_max_remaps = %d, max_1m_mrs = %d, max_8k_mrs = %d\n",
+		 device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
+		 rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_mrs,
+		 rds_ibdev->max_8k_mrs);
+
+	pr_info("RDS/IB: %s: %s supported and preferred\n",
+		device->name,
+		rds_ibdev->use_fastreg ? "FRMR" : "FMR");
+
+	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
+	INIT_LIST_HEAD(&rds_ibdev->conn_list);
+
+	down_write(&rds_ib_devices_lock);
+	list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
+	up_write(&rds_ib_devices_lock);
+	refcount_inc(&rds_ibdev->refcount);
+
+	ib_set_client_data(device, &rds_ib_client, rds_ibdev);
+	refcount_inc(&rds_ibdev->refcount);
+
+	rds_ib_nodev_connect();
+
+put_dev:
+	rds_ib_dev_put(rds_ibdev);
+}
+
+/*
+ * 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)
+		refcount_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.
+ */
+static void rds_ib_remove_one(struct ib_device *device, void *client_data)
+{
+	struct rds_ib_device *rds_ibdev = client_data;
+
+	if (!rds_ibdev)
+		return;
+
+	rds_ib_dev_shutdown(rds_ibdev);
+
+	/* stop connection attempts from getting a reference to this device. */
+	ib_set_client_data(device, &rds_ib_client, NULL);
+
+	down_write(&rds_ib_devices_lock);
+	list_del_rcu(&rds_ibdev->list);
+	up_write(&rds_ib_devices_lock);
+
+	/*
+	 * This synchronize rcu is waiting for readers of both the ib
+	 * client data and the devices list to finish before we drop
+	 * both of those references.
+	 */
+	synchronize_rcu();
+	rds_ib_dev_put(rds_ibdev);
+	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;
+	if (conn->c_isv6)
+		return 0;
+
+	iinfo->src_addr = conn->c_laddr.s6_addr32[3];
+	iinfo->dst_addr = conn->c_faddr.s6_addr32[3];
+
+	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;
+
+		ic = conn->c_transport_data;
+
+		rdma_read_gids(ic->i_cm_id, (union ib_gid *)&iinfo->src_gid,
+			       (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;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* IPv6 version of rds_ib_conn_info_visitor(). */
+static int rds6_ib_conn_info_visitor(struct rds_connection *conn,
+				     void *buffer)
+{
+	struct rds6_info_rdma_connection *iinfo6 = buffer;
+	struct rds_ib_connection *ic;
+
+	/* We will only ever look at IB transports */
+	if (conn->c_trans != &rds_ib_transport)
+		return 0;
+
+	iinfo6->src_addr = conn->c_laddr;
+	iinfo6->dst_addr = conn->c_faddr;
+
+	memset(&iinfo6->src_gid, 0, sizeof(iinfo6->src_gid));
+	memset(&iinfo6->dst_gid, 0, sizeof(iinfo6->dst_gid));
+
+	if (rds_conn_state(conn) == RDS_CONN_UP) {
+		struct rds_ib_device *rds_ibdev;
+
+		ic = conn->c_transport_data;
+		rdma_read_gids(ic->i_cm_id, (union ib_gid *)&iinfo6->src_gid,
+			       (union ib_gid *)&iinfo6->dst_gid);
+		rds_ibdev = ic->rds_ibdev;
+		iinfo6->max_send_wr = ic->i_send_ring.w_nr;
+		iinfo6->max_recv_wr = ic->i_recv_ring.w_nr;
+		iinfo6->max_send_sge = rds_ibdev->max_sge;
+		rds6_ib_get_mr_info(rds_ibdev, iinfo6);
+	}
+	return 1;
+}
+#endif
+
+static void rds_ib_ic_info(struct socket *sock, unsigned int len,
+			   struct rds_info_iterator *iter,
+			   struct rds_info_lengths *lens)
+{
+	u64 buffer[(sizeof(struct rds_info_rdma_connection) + 7) / 8];
+
+	rds_for_each_conn_info(sock, len, iter, lens,
+				rds_ib_conn_info_visitor,
+				buffer,
+				sizeof(struct rds_info_rdma_connection));
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* IPv6 version of rds_ib_ic_info(). */
+static void rds6_ib_ic_info(struct socket *sock, unsigned int len,
+			    struct rds_info_iterator *iter,
+			    struct rds_info_lengths *lens)
+{
+	u64 buffer[(sizeof(struct rds6_info_rdma_connection) + 7) / 8];
+
+	rds_for_each_conn_info(sock, len, iter, lens,
+			       rds6_ib_conn_info_visitor,
+			       buffer,
+			       sizeof(struct rds6_info_rdma_connection));
+}
+#endif
+
+/*
+ * 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(struct net *net, const struct in6_addr *addr,
+			      __u32 scope_id)
+{
+	int ret;
+	struct rdma_cm_id *cm_id;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct sockaddr_in6 sin6;
+#endif
+	struct sockaddr_in sin;
+	struct sockaddr *sa;
+	bool isv4;
+
+	isv4 = ipv6_addr_v4mapped(addr);
+	/* Create a CMA ID and try to bind it. This catches both
+	 * IB and iWARP capable NICs.
+	 */
+	cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler,
+			       NULL, RDMA_PS_TCP, IB_QPT_RC);
+	if (IS_ERR(cm_id))
+		return PTR_ERR(cm_id);
+
+	if (isv4) {
+		memset(&sin, 0, sizeof(sin));
+		sin.sin_family = AF_INET;
+		sin.sin_addr.s_addr = addr->s6_addr32[3];
+		sa = (struct sockaddr *)&sin;
+	} else {
+#if IS_ENABLED(CONFIG_IPV6)
+		memset(&sin6, 0, sizeof(sin6));
+		sin6.sin6_family = AF_INET6;
+		sin6.sin6_addr = *addr;
+		sin6.sin6_scope_id = scope_id;
+		sa = (struct sockaddr *)&sin6;
+
+		/* XXX Do a special IPv6 link local address check here.  The
+		 * reason is that rdma_bind_addr() always succeeds with IPv6
+		 * link local address regardless it is indeed configured in a
+		 * system.
+		 */
+		if (ipv6_addr_type(addr) & IPV6_ADDR_LINKLOCAL) {
+			struct net_device *dev;
+
+			if (scope_id == 0) {
+				ret = -EADDRNOTAVAIL;
+				goto out;
+			}
+
+			/* Use init_net for now as RDS is not network
+			 * name space aware.
+			 */
+			dev = dev_get_by_index(&init_net, scope_id);
+			if (!dev) {
+				ret = -EADDRNOTAVAIL;
+				goto out;
+			}
+			if (!ipv6_chk_addr(&init_net, addr, dev, 1)) {
+				dev_put(dev);
+				ret = -EADDRNOTAVAIL;
+				goto out;
+			}
+			dev_put(dev);
+		}
+#else
+		ret = -EADDRNOTAVAIL;
+		goto out;
+#endif
+	}
+
+	/* rdma_bind_addr will only succeed for IB & iWARP devices */
+	ret = rdma_bind_addr(cm_id, sa);
+	/* due to this, we will claim to support iWARP devices unless we
+	   check node_type. */
+	if (ret || !cm_id->device ||
+	    cm_id->device->node_type != RDMA_NODE_IB_CA)
+		ret = -EADDRNOTAVAIL;
+
+	rdsdebug("addr %pI6c%%%u ret %d node type %d\n",
+		 addr, scope_id, ret,
+		 cm_id->device ? cm_id->device->node_type : -1);
+
+out:
+	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);
+}
+
+static void rds_ib_set_unloading(void)
+{
+	atomic_set(&rds_ib_unloading, 1);
+}
+
+static bool rds_ib_is_unloading(struct rds_connection *conn)
+{
+	struct rds_conn_path *cp = &conn->c_path[0];
+
+	return (test_bit(RDS_DESTROY_PENDING, &cp->cp_flags) ||
+		atomic_read(&rds_ib_unloading) != 0);
+}
+
+void rds_ib_exit(void)
+{
+	rds_ib_set_unloading();
+	synchronize_rcu();
+	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds_info_deregister_func(RDS6_INFO_IB_CONNECTIONS, rds6_ib_ic_info);
+#endif
+	rds_ib_unregister_client();
+	rds_ib_destroy_nodev_conns();
+	rds_ib_sysctl_exit();
+	rds_ib_recv_exit();
+	rds_trans_unregister(&rds_ib_transport);
+	rds_ib_mr_exit();
+}
+
+struct rds_transport rds_ib_transport = {
+	.laddr_check		= rds_ib_laddr_check,
+	.xmit_path_complete	= rds_ib_xmit_path_complete,
+	.xmit			= rds_ib_xmit,
+	.xmit_rdma		= rds_ib_xmit_rdma,
+	.xmit_atomic		= rds_ib_xmit_atomic,
+	.recv_path		= rds_ib_recv_path,
+	.conn_alloc		= rds_ib_conn_alloc,
+	.conn_free		= rds_ib_conn_free,
+	.conn_path_connect	= rds_ib_conn_path_connect,
+	.conn_path_shutdown	= rds_ib_conn_path_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_unloading		= rds_ib_is_unloading,
+	.t_type			= RDS_TRANS_IB
+};
+
+int rds_ib_init(void)
+{
+	int ret;
+
+	INIT_LIST_HEAD(&rds_ib_devices);
+
+	ret = rds_ib_mr_init();
+	if (ret)
+		goto out;
+
+	ret = ib_register_client(&rds_ib_client);
+	if (ret)
+		goto out_mr_exit;
+
+	ret = rds_ib_sysctl_init();
+	if (ret)
+		goto out_ibreg;
+
+	ret = rds_ib_recv_init();
+	if (ret)
+		goto out_sysctl;
+
+	rds_trans_register(&rds_ib_transport);
+
+	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds_info_register_func(RDS6_INFO_IB_CONNECTIONS, rds6_ib_ic_info);
+#endif
+
+	goto out;
+
+out_sysctl:
+	rds_ib_sysctl_exit();
+out_ibreg:
+	rds_ib_unregister_client();
+out_mr_exit:
+	rds_ib_mr_exit();
+out:
+	return ret;
+}
+
+MODULE_LICENSE("GPL");