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