net/rds/ib.c

   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>
  40 #include <linux/slab.h>
  41 #include <linux/module.h>
  42
  43 #include "rds.h"
  44 #include "ib.h"
  45
  46 unsigned int rds_ib_fmr_1m_pool_size = RDS_FMR_1M_POOL_SIZE;
  47 unsigned int rds_ib_fmr_8k_pool_size = RDS_FMR_8K_POOL_SIZE;
  48 unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
  49
  50 module_param(rds_ib_fmr_1m_pool_size, int, 0444);
  51 MODULE_PARM_DESC(rds_ib_fmr_1m_pool_size, " Max number of 1M fmr per HCA");
  52 module_param(rds_ib_fmr_8k_pool_size, int, 0444);
  53 MODULE_PARM_DESC(rds_ib_fmr_8k_pool_size, " Max number of 8K fmr per HCA");
  54 module_param(rds_ib_retry_count, int, 0444);
  55 MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
  56
  57 /*
  58  * we have a clumsy combination of RCU and a rwsem protecting this list
  59  * because it is used both in the get_mr fast path and while blocking in
  60  * the FMR flushing path.
  61  */
  62 DECLARE_RWSEM(rds_ib_devices_lock);
  63 struct list_head rds_ib_devices;
  64
  65 /* NOTE: if also grabbing ibdev lock, grab this first */
  66 DEFINE_SPINLOCK(ib_nodev_conns_lock);
  67 LIST_HEAD(ib_nodev_conns);
  68
  69 static void rds_ib_nodev_connect(void)
  70 {
  71         struct rds_ib_connection *ic;
  72
  73         spin_lock(&ib_nodev_conns_lock);
  74         list_for_each_entry(ic, &ib_nodev_conns, ib_node)
  75                 rds_conn_connect_if_down(ic->conn);
  76         spin_unlock(&ib_nodev_conns_lock);
  77 }
  78
  79 static void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
  80 {
  81         struct rds_ib_connection *ic;
  82         unsigned long flags;
  83
  84         spin_lock_irqsave(&rds_ibdev->spinlock, flags);
  85         list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
  86                 rds_conn_drop(ic->conn);
  87         spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
  88 }
  89
  90 /*
  91  * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
  92  * from interrupt context so we push freing off into a work struct in krdsd.
  93  */
  94 static void rds_ib_dev_free(struct work_struct *work)
  95 {
  96         struct rds_ib_ipaddr *i_ipaddr, *i_next;
  97         struct rds_ib_device *rds_ibdev = container_of(work,
  98                                         struct rds_ib_device, free_work);
  99
 100         if (rds_ibdev->mr_8k_pool)
 101                 rds_ib_destroy_mr_pool(rds_ibdev->mr_8k_pool);
 102         if (rds_ibdev->mr_1m_pool)
 103                 rds_ib_destroy_mr_pool(rds_ibdev->mr_1m_pool);
 104         if (rds_ibdev->pd)
 105                 ib_dealloc_pd(rds_ibdev->pd);
 106
 107         list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
 108                 list_del(&i_ipaddr->list);
 109                 kfree(i_ipaddr);
 110         }
 111
 112         kfree(rds_ibdev);
 113 }
 114
 115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 116 {
 117         BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
 118         if (atomic_dec_and_test(&rds_ibdev->refcount))
 119                 queue_work(rds_wq, &rds_ibdev->free_work);
 120 }
 121
 122 static void rds_ib_add_one(struct ib_device *device)
 123 {
 124         struct rds_ib_device *rds_ibdev;
 125
 126         /* Only handle IB (no iWARP) devices */
 127         if (device->node_type != RDMA_NODE_IB_CA)
 128                 return;
 129
 130         rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
 131                                  ibdev_to_node(device));
 132         if (!rds_ibdev)
 133                 return;
 134
 135         spin_lock_init(&rds_ibdev->spinlock);
 136         atomic_set(&rds_ibdev->refcount, 1);
 137         INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 138
 139         rds_ibdev->max_wrs = device->attrs.max_qp_wr;
 140         rds_ibdev->max_sge = min(device->attrs.max_sge, RDS_IB_MAX_SGE);
 141
 142         rds_ibdev->fmr_max_remaps = device->attrs.max_map_per_fmr?: 32;
 143         rds_ibdev->max_1m_fmrs = device->attrs.max_mr ?
 144                 min_t(unsigned int, (device->attrs.max_mr / 2),
 145                       rds_ib_fmr_1m_pool_size) : rds_ib_fmr_1m_pool_size;
 146
 147         rds_ibdev->max_8k_fmrs = device->attrs.max_mr ?
 148                 min_t(unsigned int, ((device->attrs.max_mr / 2) * RDS_MR_8K_SCALE),
 149                       rds_ib_fmr_8k_pool_size) : rds_ib_fmr_8k_pool_size;
 150
 151         rds_ibdev->max_initiator_depth = device->attrs.max_qp_init_rd_atom;
 152         rds_ibdev->max_responder_resources = device->attrs.max_qp_rd_atom;
 153
 154         rds_ibdev->dev = device;
 155         rds_ibdev->pd = ib_alloc_pd(device);
 156         if (IS_ERR(rds_ibdev->pd)) {
 157                 rds_ibdev->pd = NULL;
 158                 goto put_dev;
 159         }
 160
 161         rds_ibdev->mr_1m_pool =
 162                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
 163         if (IS_ERR(rds_ibdev->mr_1m_pool)) {
 164                 rds_ibdev->mr_1m_pool = NULL;
 165                 goto put_dev;
 166         }
 167
 168         rds_ibdev->mr_8k_pool =
 169                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
 170         if (IS_ERR(rds_ibdev->mr_8k_pool)) {
 171                 rds_ibdev->mr_8k_pool = NULL;
 172                 goto put_dev;
 173         }
 174
 175         rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, fmr_max_remaps = %d, max_1m_fmrs = %d, max_8k_fmrs = %d\n",
 176                  device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
 177                  rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_fmrs,
 178                  rds_ibdev->max_8k_fmrs);
 179
 180         INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
 181         INIT_LIST_HEAD(&rds_ibdev->conn_list);
 182
 183         down_write(&rds_ib_devices_lock);
 184         list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 185         up_write(&rds_ib_devices_lock);
 186         atomic_inc(&rds_ibdev->refcount);
 187
 188         ib_set_client_data(device, &rds_ib_client, rds_ibdev);
 189         atomic_inc(&rds_ibdev->refcount);
 190
 191         rds_ib_nodev_connect();
 192
 193 put_dev:
 194         rds_ib_dev_put(rds_ibdev);
 195 }
 196
 197 /*
 198  * New connections use this to find the device to associate with the
 199  * connection.  It's not in the fast path so we're not concerned about the
 200  * performance of the IB call.  (As of this writing, it uses an interrupt
 201  * blocking spinlock to serialize walking a per-device list of all registered
 202  * clients.)
 203  *
 204  * RCU is used to handle incoming connections racing with device teardown.
 205  * Rather than use a lock to serialize removal from the client_data and
 206  * getting a new reference, we use an RCU grace period.  The destruction
 207  * path removes the device from client_data and then waits for all RCU
 208  * readers to finish.
 209  *
 210  * A new connection can get NULL from this if its arriving on a
 211  * device that is in the process of being removed.
 212  */
 213 struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
 214 {
 215         struct rds_ib_device *rds_ibdev;
 216
 217         rcu_read_lock();
 218         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 219         if (rds_ibdev)
 220                 atomic_inc(&rds_ibdev->refcount);
 221         rcu_read_unlock();
 222         return rds_ibdev;
 223 }
 224
 225 /*
 226  * The IB stack is letting us know that a device is going away.  This can
 227  * happen if the underlying HCA driver is removed or if PCI hotplug is removing
 228  * the pci function, for example.
 229  *
 230  * This can be called at any time and can be racing with any other RDS path.
 231  */
 232 static void rds_ib_remove_one(struct ib_device *device, void *client_data)
 233 {
 234         struct rds_ib_device *rds_ibdev = client_data;
 235
 236         if (!rds_ibdev)
 237                 return;
 238
 239         rds_ib_dev_shutdown(rds_ibdev);
 240
 241         /* stop connection attempts from getting a reference to this device. */
 242         ib_set_client_data(device, &rds_ib_client, NULL);
 243
 244         down_write(&rds_ib_devices_lock);
 245         list_del_rcu(&rds_ibdev->list);
 246         up_write(&rds_ib_devices_lock);
 247
 248         /*
 249          * This synchronize rcu is waiting for readers of both the ib
 250          * client data and the devices list to finish before we drop
 251          * both of those references.
 252          */
 253         synchronize_rcu();
 254         rds_ib_dev_put(rds_ibdev);
 255         rds_ib_dev_put(rds_ibdev);
 256 }
 257
 258 struct ib_client rds_ib_client = {
 259         .name   = "rds_ib",
 260         .add    = rds_ib_add_one,
 261         .remove = rds_ib_remove_one
 262 };
 263
 264 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 265                                     void *buffer)
 266 {
 267         struct rds_info_rdma_connection *iinfo = buffer;
 268         struct rds_ib_connection *ic;
 269
 270         /* We will only ever look at IB transports */
 271         if (conn->c_trans != &rds_ib_transport)
 272                 return 0;
 273
 274         iinfo->src_addr = conn->c_laddr;
 275         iinfo->dst_addr = conn->c_faddr;
 276
 277         memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 278         memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
 279         if (rds_conn_state(conn) == RDS_CONN_UP) {
 280                 struct rds_ib_device *rds_ibdev;
 281                 struct rdma_dev_addr *dev_addr;
 282
 283                 ic = conn->c_transport_data;
 284                 dev_addr = &ic->i_cm_id->route.addr.dev_addr;
 285
 286                 rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
 287                 rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
 288
 289                 rds_ibdev = ic->rds_ibdev;
 290                 iinfo->max_send_wr = ic->i_send_ring.w_nr;
 291                 iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
 292                 iinfo->max_send_sge = rds_ibdev->max_sge;
 293                 rds_ib_get_mr_info(rds_ibdev, iinfo);
 294         }
 295         return 1;
 296 }
 297
 298 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 299                            struct rds_info_iterator *iter,
 300                            struct rds_info_lengths *lens)
 301 {
 302         rds_for_each_conn_info(sock, len, iter, lens,
 303                                 rds_ib_conn_info_visitor,
 304                                 sizeof(struct rds_info_rdma_connection));
 305 }
 306
 307
 308 /*
 309  * Early RDS/IB was built to only bind to an address if there is an IPoIB
 310  * device with that address set.
 311  *
 312  * If it were me, I'd advocate for something more flexible.  Sending and
 313  * receiving should be device-agnostic.  Transports would try and maintain
 314  * connections between peers who have messages queued.  Userspace would be
 315  * allowed to influence which paths have priority.  We could call userspace
 316  * asserting this policy "routing".
 317  */
 318 static int rds_ib_laddr_check(struct net *net, __be32 addr)
 319 {
 320         int ret;
 321         struct rdma_cm_id *cm_id;
 322         struct sockaddr_in sin;
 323
 324         /* Create a CMA ID and try to bind it. This catches both
 325          * IB and iWARP capable NICs.
 326          */
 327         cm_id = rdma_create_id(&init_net, NULL, NULL, RDMA_PS_TCP, IB_QPT_RC);
 328         if (IS_ERR(cm_id))
 329                 return PTR_ERR(cm_id);
 330
 331         memset(&sin, 0, sizeof(sin));
 332         sin.sin_family = AF_INET;
 333         sin.sin_addr.s_addr = addr;
 334
 335         /* rdma_bind_addr will only succeed for IB & iWARP devices */
 336         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 337         /* due to this, we will claim to support iWARP devices unless we
 338            check node_type. */
 339         if (ret || !cm_id->device ||
 340             cm_id->device->node_type != RDMA_NODE_IB_CA)
 341                 ret = -EADDRNOTAVAIL;
 342
 343         rdsdebug("addr %pI4 ret %d node type %d\n",
 344                 &addr, ret,
 345                 cm_id->device ? cm_id->device->node_type : -1);
 346
 347         rdma_destroy_id(cm_id);
 348
 349         return ret;
 350 }
 351
 352 static void rds_ib_unregister_client(void)
 353 {
 354         ib_unregister_client(&rds_ib_client);
 355         /* wait for rds_ib_dev_free() to complete */
 356         flush_workqueue(rds_wq);
 357 }
 358
 359 void rds_ib_exit(void)
 360 {
 361         rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 362         rds_ib_unregister_client();
 363         rds_ib_destroy_nodev_conns();
 364         rds_ib_sysctl_exit();
 365         rds_ib_recv_exit();
 366         rds_trans_unregister(&rds_ib_transport);
 367         rds_ib_fmr_exit();
 368 }
 369
 370 struct rds_transport rds_ib_transport = {
 371         .laddr_check            = rds_ib_laddr_check,
 372         .xmit_complete          = rds_ib_xmit_complete,
 373         .xmit                   = rds_ib_xmit,
 374         .xmit_rdma              = rds_ib_xmit_rdma,
 375         .xmit_atomic            = rds_ib_xmit_atomic,
 376         .recv                   = rds_ib_recv,
 377         .conn_alloc             = rds_ib_conn_alloc,
 378         .conn_free              = rds_ib_conn_free,
 379         .conn_connect           = rds_ib_conn_connect,
 380         .conn_shutdown          = rds_ib_conn_shutdown,
 381         .inc_copy_to_user       = rds_ib_inc_copy_to_user,
 382         .inc_free               = rds_ib_inc_free,
 383         .cm_initiate_connect    = rds_ib_cm_initiate_connect,
 384         .cm_handle_connect      = rds_ib_cm_handle_connect,
 385         .cm_connect_complete    = rds_ib_cm_connect_complete,
 386         .stats_info_copy        = rds_ib_stats_info_copy,
 387         .exit                   = rds_ib_exit,
 388         .get_mr                 = rds_ib_get_mr,
 389         .sync_mr                = rds_ib_sync_mr,
 390         .free_mr                = rds_ib_free_mr,
 391         .flush_mrs              = rds_ib_flush_mrs,
 392         .t_owner                = THIS_MODULE,
 393         .t_name                 = "infiniband",
 394         .t_type                 = RDS_TRANS_IB
 395 };
 396
 397 int rds_ib_init(void)
 398 {
 399         int ret;
 400
 401         INIT_LIST_HEAD(&rds_ib_devices);
 402
 403         ret = rds_ib_fmr_init();
 404         if (ret)
 405                 goto out;
 406
 407         ret = ib_register_client(&rds_ib_client);
 408         if (ret)
 409                 goto out_fmr_exit;
 410
 411         ret = rds_ib_sysctl_init();
 412         if (ret)
 413                 goto out_ibreg;
 414
 415         ret = rds_ib_recv_init();
 416         if (ret)
 417                 goto out_sysctl;
 418
 419         ret = rds_trans_register(&rds_ib_transport);
 420         if (ret)
 421                 goto out_recv;
 422
 423         rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 424
 425         goto out;
 426
 427 out_recv:
 428         rds_ib_recv_exit();
 429 out_sysctl:
 430         rds_ib_sysctl_exit();
 431 out_ibreg:
 432         rds_ib_unregister_client();
 433 out_fmr_exit:
 434         rds_ib_fmr_exit();
 435 out:
 436         return ret;
 437 }
 438
 439 MODULE_LICENSE("GPL");
 440