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 = kzalloc(sizeof(int) * device->num_comp_vectors,
 167                                          GFP_KERNEL);
 168         if (!rds_ibdev->vector_load) {
 169                 pr_err("RDS/IB: %s failed to allocate vector memory\n",
 170                         __func__);
 171                 goto put_dev;
 172         }
 173
 174         rds_ibdev->dev = device;
 175         rds_ibdev->pd = ib_alloc_pd(device, 0);
 176         if (IS_ERR(rds_ibdev->pd)) {
 177                 rds_ibdev->pd = NULL;
 178                 goto put_dev;
 179         }
 180
 181         rds_ibdev->mr_1m_pool =
 182                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
 183         if (IS_ERR(rds_ibdev->mr_1m_pool)) {
 184                 rds_ibdev->mr_1m_pool = NULL;
 185                 goto put_dev;
 186         }
 187
 188         rds_ibdev->mr_8k_pool =
 189                 rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
 190         if (IS_ERR(rds_ibdev->mr_8k_pool)) {
 191                 rds_ibdev->mr_8k_pool = NULL;
 192                 goto put_dev;
 193         }
 194
 195         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",
 196                  device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
 197                  rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_mrs,
 198                  rds_ibdev->max_8k_mrs);
 199
 200         pr_info("RDS/IB: %s: %s supported and preferred\n",
 201                 device->name,
 202                 rds_ibdev->use_fastreg ? "FRMR" : "FMR");
 203
 204         INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
 205         INIT_LIST_HEAD(&rds_ibdev->conn_list);
 206
 207         down_write(&rds_ib_devices_lock);
 208         list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 209         up_write(&rds_ib_devices_lock);
 210         refcount_inc(&rds_ibdev->refcount);
 211
 212         ib_set_client_data(device, &rds_ib_client, rds_ibdev);
 213         refcount_inc(&rds_ibdev->refcount);
 214
 215         rds_ib_nodev_connect();
 216
 217 put_dev:
 218         rds_ib_dev_put(rds_ibdev);
 219 }
 220
 221 /*
 222  * New connections use this to find the device to associate with the
 223  * connection.  It's not in the fast path so we're not concerned about the
 224  * performance of the IB call.  (As of this writing, it uses an interrupt
 225  * blocking spinlock to serialize walking a per-device list of all registered
 226  * clients.)
 227  *
 228  * RCU is used to handle incoming connections racing with device teardown.
 229  * Rather than use a lock to serialize removal from the client_data and
 230  * getting a new reference, we use an RCU grace period.  The destruction
 231  * path removes the device from client_data and then waits for all RCU
 232  * readers to finish.
 233  *
 234  * A new connection can get NULL from this if its arriving on a
 235  * device that is in the process of being removed.
 236  */
 237 struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
 238 {
 239         struct rds_ib_device *rds_ibdev;
 240
 241         rcu_read_lock();
 242         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 243         if (rds_ibdev)
 244                 refcount_inc(&rds_ibdev->refcount);
 245         rcu_read_unlock();
 246         return rds_ibdev;
 247 }
 248
 249 /*
 250  * The IB stack is letting us know that a device is going away.  This can
 251  * happen if the underlying HCA driver is removed or if PCI hotplug is removing
 252  * the pci function, for example.
 253  *
 254  * This can be called at any time and can be racing with any other RDS path.
 255  */
 256 static void rds_ib_remove_one(struct ib_device *device, void *client_data)
 257 {
 258         struct rds_ib_device *rds_ibdev = client_data;
 259
 260         if (!rds_ibdev)
 261                 return;
 262
 263         rds_ib_dev_shutdown(rds_ibdev);
 264
 265         /* stop connection attempts from getting a reference to this device. */
 266         ib_set_client_data(device, &rds_ib_client, NULL);
 267
 268         down_write(&rds_ib_devices_lock);
 269         list_del_rcu(&rds_ibdev->list);
 270         up_write(&rds_ib_devices_lock);
 271
 272         /*
 273          * This synchronize rcu is waiting for readers of both the ib
 274          * client data and the devices list to finish before we drop
 275          * both of those references.
 276          */
 277         synchronize_rcu();
 278         rds_ib_dev_put(rds_ibdev);
 279         rds_ib_dev_put(rds_ibdev);
 280 }
 281
 282 struct ib_client rds_ib_client = {
 283         .name   = "rds_ib",
 284         .add    = rds_ib_add_one,
 285         .remove = rds_ib_remove_one
 286 };
 287
 288 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 289                                     void *buffer)
 290 {
 291         struct rds_info_rdma_connection *iinfo = buffer;
 292         struct rds_ib_connection *ic;
 293
 294         /* We will only ever look at IB transports */
 295         if (conn->c_trans != &rds_ib_transport)
 296                 return 0;
 297
 298         iinfo->src_addr = conn->c_laddr;
 299         iinfo->dst_addr = conn->c_faddr;
 300
 301         memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 302         memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
 303         if (rds_conn_state(conn) == RDS_CONN_UP) {
 304                 struct rds_ib_device *rds_ibdev;
 305
 306                 ic = conn->c_transport_data;
 307
 308                 rdma_read_gids(ic->i_cm_id, (union ib_gid *)&iinfo->src_gid,
 309                                (union ib_gid *)&iinfo->dst_gid);
 310
 311                 rds_ibdev = ic->rds_ibdev;
 312                 iinfo->max_send_wr = ic->i_send_ring.w_nr;
 313                 iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
 314                 iinfo->max_send_sge = rds_ibdev->max_sge;
 315                 rds_ib_get_mr_info(rds_ibdev, iinfo);
 316         }
 317         return 1;
 318 }
 319
 320 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 321                            struct rds_info_iterator *iter,
 322                            struct rds_info_lengths *lens)
 323 {
 324         rds_for_each_conn_info(sock, len, iter, lens,
 325                                 rds_ib_conn_info_visitor,
 326                                 sizeof(struct rds_info_rdma_connection));
 327 }
 328
 329
 330 /*
 331  * Early RDS/IB was built to only bind to an address if there is an IPoIB
 332  * device with that address set.
 333  *
 334  * If it were me, I'd advocate for something more flexible.  Sending and
 335  * receiving should be device-agnostic.  Transports would try and maintain
 336  * connections between peers who have messages queued.  Userspace would be
 337  * allowed to influence which paths have priority.  We could call userspace
 338  * asserting this policy "routing".
 339  */
 340 static int rds_ib_laddr_check(struct net *net, __be32 addr)
 341 {
 342         int ret;
 343         struct rdma_cm_id *cm_id;
 344         struct sockaddr_in sin;
 345
 346         /* Create a CMA ID and try to bind it. This catches both
 347          * IB and iWARP capable NICs.
 348          */
 349         cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler,
 350                                NULL, RDMA_PS_TCP, IB_QPT_RC);
 351         if (IS_ERR(cm_id))
 352                 return PTR_ERR(cm_id);
 353
 354         memset(&sin, 0, sizeof(sin));
 355         sin.sin_family = AF_INET;
 356         sin.sin_addr.s_addr = addr;
 357
 358         /* rdma_bind_addr will only succeed for IB & iWARP devices */
 359         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 360         /* due to this, we will claim to support iWARP devices unless we
 361            check node_type. */
 362         if (ret || !cm_id->device ||
 363             cm_id->device->node_type != RDMA_NODE_IB_CA)
 364                 ret = -EADDRNOTAVAIL;
 365
 366         rdsdebug("addr %pI4 ret %d node type %d\n",
 367                 &addr, ret,
 368                 cm_id->device ? cm_id->device->node_type : -1);
 369
 370         rdma_destroy_id(cm_id);
 371
 372         return ret;
 373 }
 374
 375 static void rds_ib_unregister_client(void)
 376 {
 377         ib_unregister_client(&rds_ib_client);
 378         /* wait for rds_ib_dev_free() to complete */
 379         flush_workqueue(rds_wq);
 380 }
 381
 382 static void rds_ib_set_unloading(void)
 383 {
 384         atomic_set(&rds_ib_unloading, 1);
 385 }
 386
 387 static bool rds_ib_is_unloading(struct rds_connection *conn)
 388 {
 389         struct rds_conn_path *cp = &conn->c_path[0];
 390
 391         return (test_bit(RDS_DESTROY_PENDING, &cp->cp_flags) ||
 392                 atomic_read(&rds_ib_unloading) != 0);
 393 }
 394
 395 void rds_ib_exit(void)
 396 {
 397         rds_ib_set_unloading();
 398         synchronize_rcu();
 399         rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 400         rds_ib_unregister_client();
 401         rds_ib_destroy_nodev_conns();
 402         rds_ib_sysctl_exit();
 403         rds_ib_recv_exit();
 404         rds_trans_unregister(&rds_ib_transport);
 405         rds_ib_mr_exit();
 406 }
 407
 408 struct rds_transport rds_ib_transport = {
 409         .laddr_check            = rds_ib_laddr_check,
 410         .xmit_path_complete     = rds_ib_xmit_path_complete,
 411         .xmit                   = rds_ib_xmit,
 412         .xmit_rdma              = rds_ib_xmit_rdma,
 413         .xmit_atomic            = rds_ib_xmit_atomic,
 414         .recv_path              = rds_ib_recv_path,
 415         .conn_alloc             = rds_ib_conn_alloc,
 416         .conn_free              = rds_ib_conn_free,
 417         .conn_path_connect      = rds_ib_conn_path_connect,
 418         .conn_path_shutdown     = rds_ib_conn_path_shutdown,
 419         .inc_copy_to_user       = rds_ib_inc_copy_to_user,
 420         .inc_free               = rds_ib_inc_free,
 421         .cm_initiate_connect    = rds_ib_cm_initiate_connect,
 422         .cm_handle_connect      = rds_ib_cm_handle_connect,
 423         .cm_connect_complete    = rds_ib_cm_connect_complete,
 424         .stats_info_copy        = rds_ib_stats_info_copy,
 425         .exit                   = rds_ib_exit,
 426         .get_mr                 = rds_ib_get_mr,
 427         .sync_mr                = rds_ib_sync_mr,
 428         .free_mr                = rds_ib_free_mr,
 429         .flush_mrs              = rds_ib_flush_mrs,
 430         .t_owner                = THIS_MODULE,
 431         .t_name                 = "infiniband",
 432         .t_unloading            = rds_ib_is_unloading,
 433         .t_type                 = RDS_TRANS_IB
 434 };
 435
 436 int rds_ib_init(void)
 437 {
 438         int ret;
 439
 440         INIT_LIST_HEAD(&rds_ib_devices);
 441
 442         ret = rds_ib_mr_init();
 443         if (ret)
 444                 goto out;
 445
 446         ret = ib_register_client(&rds_ib_client);
 447         if (ret)
 448                 goto out_mr_exit;
 449
 450         ret = rds_ib_sysctl_init();
 451         if (ret)
 452                 goto out_ibreg;
 453
 454         ret = rds_ib_recv_init();
 455         if (ret)
 456                 goto out_sysctl;
 457
 458         rds_trans_register(&rds_ib_transport);
 459
 460         rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 461
 462         goto out;
 463
 464 out_sysctl:
 465         rds_ib_sysctl_exit();
 466 out_ibreg:
 467         rds_ib_unregister_client();
 468 out_mr_exit:
 469         rds_ib_mr_exit();
 470 out:
 471         return ret;
 472 }
 473
 474 MODULE_LICENSE("GPL");
 475