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