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_single_path.h"
  44 #include "rds.h"
  45 #include "ib.h"
  46 #include "ib_mr.h"
  47
  48 static unsigned int rds_ib_mr_1m_pool_size = RDS_MR_1M_POOL_SIZE;
  49 static unsigned int rds_ib_mr_8k_pool_size = RDS_MR_8K_POOL_SIZE;
  50 unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
  51 static atomic_t rds_ib_unloading;
  52
  53 module_param(rds_ib_mr_1m_pool_size, int, 0444);
  54 MODULE_PARM_DESC(rds_ib_mr_1m_pool_size, " Max number of 1M mr per HCA");
  55 module_param(rds_ib_mr_8k_pool_size, int, 0444);
  56 MODULE_PARM_DESC(rds_ib_mr_8k_pool_size, " Max number of 8K mr per HCA");
  57 module_param(rds_ib_retry_count, int, 0444);
  58 MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
  59
  60 /*
  61  * we have a clumsy combination of RCU and a rwsem protecting this list
  62  * because it is used both in the get_mr fast path and while blocking in
  63  * the FMR flushing path.
  64  */
  65 DECLARE_RWSEM(rds_ib_devices_lock);
  66 struct list_head rds_ib_devices;
  67
  68 /* NOTE: if also grabbing ibdev lock, grab this first */
  69 DEFINE_SPINLOCK(ib_nodev_conns_lock);
  70 LIST_HEAD(ib_nodev_conns);
  71
  72 static void rds_ib_nodev_connect(void)
  73 {
  74         struct rds_ib_connection *ic;
  75
  76         spin_lock(&ib_nodev_conns_lock);
  77         list_for_each_entry(ic, &ib_nodev_conns, ib_node)
  78                 rds_conn_connect_if_down(ic->conn);
  79         spin_unlock(&ib_nodev_conns_lock);
  80 }
  81
  82 static void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
  83 {
  84         struct rds_ib_connection *ic;
  85         unsigned long flags;
  86
  87         spin_lock_irqsave(&rds_ibdev->spinlock, flags);
  88         list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
  89                 rds_conn_drop(ic->conn);
  90         spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
  91 }
  92
  93 /*
  94  * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
  95  * from interrupt context so we push freing off into a work struct in krdsd.
  96  */
  97 static void rds_ib_dev_free(struct work_struct *work)
  98 {
  99         struct rds_ib_ipaddr *i_ipaddr, *i_next;
 100         struct rds_ib_device *rds_ibdev = container_of(work,
 101                                         struct rds_ib_device, free_work);
 102
 103         if (rds_ibdev->mr_8k_pool)
 104                 rds_ib_destroy_mr_pool(rds_ibdev->mr_8k_pool);
 105         if (rds_ibdev->mr_1m_pool)
 106                 rds_ib_destroy_mr_pool(rds_ibdev->mr_1m_pool);
 107         if (rds_ibdev->pd)
 108                 ib_dealloc_pd(rds_ibdev->pd);
 109
 110         list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
 111                 list_del(&i_ipaddr->list);
 112                 kfree(i_ipaddr);
 113         }
 114
 115         kfree(rds_ibdev->vector_load);
 116
 117         kfree(rds_ibdev);
 118 }
 119
 120 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 121 {
 122         BUG_ON(refcount_read(&rds_ibdev->refcount) == 0);
 123         if (refcount_dec_and_test(&rds_ibdev->refcount))
 124                 queue_work(rds_wq, &rds_ibdev->free_work);
 125 }
 126
 127 static void rds_ib_add_one(struct ib_device *device)
 128 {
 129         struct rds_ib_device *rds_ibdev;
 130         bool has_fr, has_fmr;
 131
 132         /* Only handle IB (no iWARP) devices */
 133         if (device->node_type != RDMA_NODE_IB_CA)
 134                 return;
 135
 136         rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
 137                                  ibdev_to_node(device));
 138         if (!rds_ibdev)
 139                 return;
 140
 141         spin_lock_init(&rds_ibdev->spinlock);
 142         refcount_set(&rds_ibdev->refcount, 1);
 143         INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 144
 145         rds_ibdev->max_wrs = device->attrs.max_qp_wr;
 146         rds_ibdev->max_sge = min(device->attrs.max_sge, RDS_IB_MAX_SGE);
 147
 148         has_fr = (device->attrs.device_cap_flags &
 149                   IB_DEVICE_MEM_MGT_EXTENSIONS);
 150         has_fmr = (device->alloc_fmr && device->dealloc_fmr &&
 151                    device->map_phys_fmr && device->unmap_fmr);
 152         rds_ibdev->use_fastreg = (has_fr && !has_fmr);
 153
 154         rds_ibdev->fmr_max_remaps = device->attrs.max_map_per_fmr?: 32;
 155         rds_ibdev->max_1m_mrs = device->attrs.max_mr ?
 156                 min_t(unsigned int, (device->attrs.max_mr / 2),
 157                       rds_ib_mr_1m_pool_size) : rds_ib_mr_1m_pool_size;
 158
 159         rds_ibdev->max_8k_mrs = device->attrs.max_mr ?
 160                 min_t(unsigned int, ((device->attrs.max_mr / 2) * RDS_MR_8K_SCALE),
 161                       rds_ib_mr_8k_pool_size) : rds_ib_mr_8k_pool_size;
 162
 163         rds_ibdev->max_initiator_depth = device->attrs.max_qp_init_rd_atom;
 164         rds_ibdev->max_responder_resources = device->attrs.max_qp_rd_atom;
 165
 166         rds_ibdev->vector_load = kcalloc(device->num_comp_vectors,
 167                                          sizeof(int),
 168                                          GFP_KERNEL);
 169         if (!rds_ibdev->vector_load) {
 170                 pr_err("RDS/IB: %s failed to allocate vector memory\n",
 171                         __func__);
 172                 goto put_dev;
 173         }
 174
 175         rds_ibdev->dev = device;
 176         rds_ibdev->pd = ib_alloc_pd(device, 0);
 177         if (IS_ERR(rds_ibdev->pd)) {
 178                 rds_ibdev->pd = NULL;
 179                 goto put_dev;
 180         }
 181
 182         rds_ibdev->mr_1m_pool =
 183                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
 184         if (IS_ERR(rds_ibdev->mr_1m_pool)) {
 185                 rds_ibdev->mr_1m_pool = NULL;
 186                 goto put_dev;
 187         }
 188
 189         rds_ibdev->mr_8k_pool =
 190                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
 191         if (IS_ERR(rds_ibdev->mr_8k_pool)) {
 192                 rds_ibdev->mr_8k_pool = NULL;
 193                 goto put_dev;
 194         }
 195
 196         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",
 197                  device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
 198                  rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_mrs,
 199                  rds_ibdev->max_8k_mrs);
 200
 201         pr_info("RDS/IB: %s: %s supported and preferred\n",
 202                 device->name,
 203                 rds_ibdev->use_fastreg ? "FRMR" : "FMR");
 204
 205         INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
 206         INIT_LIST_HEAD(&rds_ibdev->conn_list);
 207
 208         down_write(&rds_ib_devices_lock);
 209         list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 210         up_write(&rds_ib_devices_lock);
 211         refcount_inc(&rds_ibdev->refcount);
 212
 213         ib_set_client_data(device, &rds_ib_client, rds_ibdev);
 214         refcount_inc(&rds_ibdev->refcount);
 215
 216         rds_ib_nodev_connect();
 217
 218 put_dev:
 219         rds_ib_dev_put(rds_ibdev);
 220 }
 221
 222 /*
 223  * New connections use this to find the device to associate with the
 224  * connection.  It's not in the fast path so we're not concerned about the
 225  * performance of the IB call.  (As of this writing, it uses an interrupt
 226  * blocking spinlock to serialize walking a per-device list of all registered
 227  * clients.)
 228  *
 229  * RCU is used to handle incoming connections racing with device teardown.
 230  * Rather than use a lock to serialize removal from the client_data and
 231  * getting a new reference, we use an RCU grace period.  The destruction
 232  * path removes the device from client_data and then waits for all RCU
 233  * readers to finish.
 234  *
 235  * A new connection can get NULL from this if its arriving on a
 236  * device that is in the process of being removed.
 237  */
 238 struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
 239 {
 240         struct rds_ib_device *rds_ibdev;
 241
 242         rcu_read_lock();
 243         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 244         if (rds_ibdev)
 245                 refcount_inc(&rds_ibdev->refcount);
 246         rcu_read_unlock();
 247         return rds_ibdev;
 248 }
 249
 250 /*
 251  * The IB stack is letting us know that a device is going away.  This can
 252  * happen if the underlying HCA driver is removed or if PCI hotplug is removing
 253  * the pci function, for example.
 254  *
 255  * This can be called at any time and can be racing with any other RDS path.
 256  */
 257 static void rds_ib_remove_one(struct ib_device *device, void *client_data)
 258 {
 259         struct rds_ib_device *rds_ibdev = client_data;
 260
 261         if (!rds_ibdev)
 262                 return;
 263
 264         rds_ib_dev_shutdown(rds_ibdev);
 265
 266         /* stop connection attempts from getting a reference to this device. */
 267         ib_set_client_data(device, &rds_ib_client, NULL);
 268
 269         down_write(&rds_ib_devices_lock);
 270         list_del_rcu(&rds_ibdev->list);
 271         up_write(&rds_ib_devices_lock);
 272
 273         /*
 274          * This synchronize rcu is waiting for readers of both the ib
 275          * client data and the devices list to finish before we drop
 276          * both of those references.
 277          */
 278         synchronize_rcu();
 279         rds_ib_dev_put(rds_ibdev);
 280         rds_ib_dev_put(rds_ibdev);
 281 }
 282
 283 struct ib_client rds_ib_client = {
 284         .name   = "rds_ib",
 285         .add    = rds_ib_add_one,
 286         .remove = rds_ib_remove_one
 287 };
 288
 289 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 290                                     void *buffer)
 291 {
 292         struct rds_info_rdma_connection *iinfo = buffer;
 293         struct rds_ib_connection *ic;
 294
 295         /* We will only ever look at IB transports */
 296         if (conn->c_trans != &rds_ib_transport)
 297                 return 0;
 298
 299         iinfo->src_addr = conn->c_laddr;
 300         iinfo->dst_addr = conn->c_faddr;
 301
 302         memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 303         memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
 304         if (rds_conn_state(conn) == RDS_CONN_UP) {
 305                 struct rds_ib_device *rds_ibdev;
 306
 307                 ic = conn->c_transport_data;
 308
 309                 rdma_read_gids(ic->i_cm_id, (union ib_gid *)&iinfo->src_gid,
 310                                (union ib_gid *)&iinfo->dst_gid);
 311
 312                 rds_ibdev = ic->rds_ibdev;
 313                 iinfo->max_send_wr = ic->i_send_ring.w_nr;
 314                 iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
 315                 iinfo->max_send_sge = rds_ibdev->max_sge;
 316                 rds_ib_get_mr_info(rds_ibdev, iinfo);
 317         }
 318         return 1;
 319 }
 320
 321 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 322                            struct rds_info_iterator *iter,
 323                            struct rds_info_lengths *lens)
 324 {
 325         u64 buffer[(sizeof(struct rds_info_rdma_connection) + 7) / 8];
 326
 327         rds_for_each_conn_info(sock, len, iter, lens,
 328                                 rds_ib_conn_info_visitor,
 329                                 buffer,
 330                                 sizeof(struct rds_info_rdma_connection));
 331 }
 332
 333
 334 /*
 335  * Early RDS/IB was built to only bind to an address if there is an IPoIB
 336  * device with that address set.
 337  *
 338  * If it were me, I'd advocate for something more flexible.  Sending and
 339  * receiving should be device-agnostic.  Transports would try and maintain
 340  * connections between peers who have messages queued.  Userspace would be
 341  * allowed to influence which paths have priority.  We could call userspace
 342  * asserting this policy "routing".
 343  */
 344 static int rds_ib_laddr_check(struct net *net, __be32 addr)
 345 {
 346         int ret;
 347         struct rdma_cm_id *cm_id;
 348         struct sockaddr_in sin;
 349
 350         /* Create a CMA ID and try to bind it. This catches both
 351          * IB and iWARP capable NICs.
 352          */
 353         cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler,
 354                                NULL, RDMA_PS_TCP, IB_QPT_RC);
 355         if (IS_ERR(cm_id))
 356                 return PTR_ERR(cm_id);
 357
 358         memset(&sin, 0, sizeof(sin));
 359         sin.sin_family = AF_INET;
 360         sin.sin_addr.s_addr = addr;
 361
 362         /* rdma_bind_addr will only succeed for IB & iWARP devices */
 363         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 364         /* due to this, we will claim to support iWARP devices unless we
 365            check node_type. */
 366         if (ret || !cm_id->device ||
 367             cm_id->device->node_type != RDMA_NODE_IB_CA)
 368                 ret = -EADDRNOTAVAIL;
 369
 370         rdsdebug("addr %pI4 ret %d node type %d\n",
 371                 &addr, ret,
 372                 cm_id->device ? cm_id->device->node_type : -1);
 373
 374         rdma_destroy_id(cm_id);
 375
 376         return ret;
 377 }
 378
 379 static void rds_ib_unregister_client(void)
 380 {
 381         ib_unregister_client(&rds_ib_client);
 382         /* wait for rds_ib_dev_free() to complete */
 383         flush_workqueue(rds_wq);
 384 }
 385
 386 static void rds_ib_set_unloading(void)
 387 {
 388         atomic_set(&rds_ib_unloading, 1);
 389 }
 390
 391 static bool rds_ib_is_unloading(struct rds_connection *conn)
 392 {
 393         struct rds_conn_path *cp = &conn->c_path[0];
 394
 395         return (test_bit(RDS_DESTROY_PENDING, &cp->cp_flags) ||
 396                 atomic_read(&rds_ib_unloading) != 0);
 397 }
 398
 399 void rds_ib_exit(void)
 400 {
 401         rds_ib_set_unloading();
 402         synchronize_rcu();
 403         rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 404         rds_ib_unregister_client();
 405         rds_ib_destroy_nodev_conns();
 406         rds_ib_sysctl_exit();
 407         rds_ib_recv_exit();
 408         rds_trans_unregister(&rds_ib_transport);
 409         rds_ib_mr_exit();
 410 }
 411
 412 struct rds_transport rds_ib_transport = {
 413         .laddr_check            = rds_ib_laddr_check,
 414         .xmit_path_complete     = rds_ib_xmit_path_complete,
 415         .xmit                   = rds_ib_xmit,
 416         .xmit_rdma              = rds_ib_xmit_rdma,
 417         .xmit_atomic            = rds_ib_xmit_atomic,
 418         .recv_path              = rds_ib_recv_path,
 419         .conn_alloc             = rds_ib_conn_alloc,
 420         .conn_free              = rds_ib_conn_free,
 421         .conn_path_connect      = rds_ib_conn_path_connect,
 422         .conn_path_shutdown     = rds_ib_conn_path_shutdown,
 423         .inc_copy_to_user       = rds_ib_inc_copy_to_user,
 424         .inc_free               = rds_ib_inc_free,
 425         .cm_initiate_connect    = rds_ib_cm_initiate_connect,
 426         .cm_handle_connect      = rds_ib_cm_handle_connect,
 427         .cm_connect_complete    = rds_ib_cm_connect_complete,
 428         .stats_info_copy        = rds_ib_stats_info_copy,
 429         .exit                   = rds_ib_exit,
 430         .get_mr                 = rds_ib_get_mr,
 431         .sync_mr                = rds_ib_sync_mr,
 432         .free_mr                = rds_ib_free_mr,
 433         .flush_mrs              = rds_ib_flush_mrs,
 434         .t_owner                = THIS_MODULE,
 435         .t_name                 = "infiniband",
 436         .t_unloading            = rds_ib_is_unloading,
 437         .t_type                 = RDS_TRANS_IB
 438 };
 439
 440 int rds_ib_init(void)
 441 {
 442         int ret;
 443
 444         INIT_LIST_HEAD(&rds_ib_devices);
 445
 446         ret = rds_ib_mr_init();
 447         if (ret)
 448                 goto out;
 449
 450         ret = ib_register_client(&rds_ib_client);
 451         if (ret)
 452                 goto out_mr_exit;
 453
 454         ret = rds_ib_sysctl_init();
 455         if (ret)
 456                 goto out_ibreg;
 457
 458         ret = rds_ib_recv_init();
 459         if (ret)
 460                 goto out_sysctl;
 461
 462         rds_trans_register(&rds_ib_transport);
 463
 464         rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 465
 466         goto out;
 467
 468 out_sysctl:
 469         rds_ib_sysctl_exit();
 470 out_ibreg:
 471         rds_ib_unregister_client();
 472 out_mr_exit:
 473         rds_ib_mr_exit();
 474 out:
 475         return ret;
 476 }
 477
 478 MODULE_LICENSE("GPL");
 479