/*
   * 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 <linux/module.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;
  
  /* NOTE: if also grabbing iwdev lock, grab this first */
  DEFINE_SPINLOCK(iw_nodev_conns_lock);
  LIST_HEAD(iw_nodev_conns);
  
  static 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
  ", 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->dev = device;
  	rds_iwdev->pd = ib_alloc_pd(device);
  	if (IS_ERR(rds_iwdev->pd))
  		goto free_dev;
  
  	if (!rds_iwdev->dma_local_lkey) {
  		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);
  }
  
  static 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_destroy_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
  ", 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;
  
  		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_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, IB_QPT_RC);
  	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 IB devices unless we
  	   check node_type. */
  	if (ret || !cm_id->device ||
  	    cm_id->device->node_type != RDMA_NODE_RNIC)
  		ret = -EADDRNOTAVAIL;
  
  	rdsdebug("addr %pI4 ret %d node type %d
  ",
  		&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_destroy_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_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_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_type			= RDS_TRANS_IWARP,
  	.t_prefer_loopback	= 1,
  };
  
  int 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");