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
  42 #include "rds.h"
  43 #include "ib.h"
  44
  45 static unsigned int fmr_pool_size = RDS_FMR_POOL_SIZE;
  46 unsigned int fmr_message_size = RDS_FMR_SIZE + 1; /* +1 allows for unaligned MRs */
  47 unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
  48
  49 module_param(fmr_pool_size, int, 0444);
  50 MODULE_PARM_DESC(fmr_pool_size, " Max number of fmr per HCA");
  51 module_param(fmr_message_size, int, 0444);
  52 MODULE_PARM_DESC(fmr_message_size, " Max size of a RDMA transfer");
  53 module_param(rds_ib_retry_count, int, 0444);
  54 MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
  55
  56 /*
  57  * we have a clumsy combination of RCU and a rwsem protecting this list
  58  * because it is used both in the get_mr fast path and while blocking in
  59  * the FMR flushing path.
  60  */
  61 DECLARE_RWSEM(rds_ib_devices_lock);
  62 struct list_head rds_ib_devices;
  63
  64 /* NOTE: if also grabbing ibdev lock, grab this first */
  65 DEFINE_SPINLOCK(ib_nodev_conns_lock);
  66 LIST_HEAD(ib_nodev_conns);
  67
  68 static void rds_ib_nodev_connect(void)
  69 {
  70         struct rds_ib_connection *ic;
  71
  72         spin_lock(&ib_nodev_conns_lock);
  73         list_for_each_entry(ic, &ib_nodev_conns, ib_node)
  74                 rds_conn_connect_if_down(ic->conn);
  75         spin_unlock(&ib_nodev_conns_lock);
  76 }
  77
  78 static void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
  79 {
  80         struct rds_ib_connection *ic;
  81         unsigned long flags;
  82
  83         spin_lock_irqsave(&rds_ibdev->spinlock, flags);
  84         list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
  85                 rds_conn_drop(ic->conn);
  86         spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
  87 }
  88
  89 /*
  90  * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
  91  * from interrupt context so we push freing off into a work struct in krdsd.
  92  */
  93 static void rds_ib_dev_free(struct work_struct *work)
  94 {
  95         struct rds_ib_ipaddr *i_ipaddr, *i_next;
  96         struct rds_ib_device *rds_ibdev = container_of(work,
  97                                         struct rds_ib_device, free_work);
  98
  99         if (rds_ibdev->mr_pool)
 100                 rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
 101         if (rds_ibdev->mr)
 102                 ib_dereg_mr(rds_ibdev->mr);
 103         if (rds_ibdev->pd)
 104                 ib_dealloc_pd(rds_ibdev->pd);
 105
 106         list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
 107                 list_del(&i_ipaddr->list);
 108                 kfree(i_ipaddr);
 109         }
 110
 111         kfree(rds_ibdev);
 112 }
 113
 114 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 115 {
 116         BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
 117         if (atomic_dec_and_test(&rds_ibdev->refcount))
 118                 queue_work(rds_wq, &rds_ibdev->free_work);
 119 }
 120
 121 static void rds_ib_add_one(struct ib_device *device)
 122 {
 123         struct rds_ib_device *rds_ibdev;
 124         struct ib_device_attr *dev_attr;
 125
 126         /* Only handle IB (no iWARP) devices */
 127         if (device->node_type != RDMA_NODE_IB_CA)
 128                 return;
 129
 130         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
 131         if (!dev_attr)
 132                 return;
 133
 134         if (ib_query_device(device, dev_attr)) {
 135                 rdsdebug("Query device failed for %s\n", device->name);
 136                 goto free_attr;
 137         }
 138
 139         rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
 140                                  ibdev_to_node(device));
 141         if (!rds_ibdev)
 142                 goto free_attr;
 143
 144         spin_lock_init(&rds_ibdev->spinlock);
 145         atomic_set(&rds_ibdev->refcount, 1);
 146         INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 147
 148         rds_ibdev->max_wrs = dev_attr->max_qp_wr;
 149         rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
 150
 151         rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
 152         rds_ibdev->max_fmrs = dev_attr->max_fmr ?
 153                         min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
 154                         fmr_pool_size;
 155
 156         rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
 157         rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
 158
 159         rds_ibdev->dev = device;
 160         rds_ibdev->pd = ib_alloc_pd(device);
 161         if (IS_ERR(rds_ibdev->pd)) {
 162                 rds_ibdev->pd = NULL;
 163                 goto put_dev;
 164         }
 165
 166         rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE);
 167         if (IS_ERR(rds_ibdev->mr)) {
 168                 rds_ibdev->mr = NULL;
 169                 goto put_dev;
 170         }
 171
 172         rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
 173         if (IS_ERR(rds_ibdev->mr_pool)) {
 174                 rds_ibdev->mr_pool = NULL;
 175                 goto put_dev;
 176         }
 177
 178         INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
 179         INIT_LIST_HEAD(&rds_ibdev->conn_list);
 180
 181         down_write(&rds_ib_devices_lock);
 182         list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 183         up_write(&rds_ib_devices_lock);
 184         atomic_inc(&rds_ibdev->refcount);
 185
 186         ib_set_client_data(device, &rds_ib_client, rds_ibdev);
 187         atomic_inc(&rds_ibdev->refcount);
 188
 189         rds_ib_nodev_connect();
 190
 191 put_dev:
 192         rds_ib_dev_put(rds_ibdev);
 193 free_attr:
 194         kfree(dev_attr);
 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)
 233 {
 234         struct rds_ib_device *rds_ibdev;
 235
 236         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 237         if (!rds_ibdev)
 238                 return;
 239
 240         rds_ib_dev_shutdown(rds_ibdev);
 241
 242         /* stop connection attempts from getting a reference to this device. */
 243         ib_set_client_data(device, &rds_ib_client, NULL);
 244
 245         down_write(&rds_ib_devices_lock);
 246         list_del_rcu(&rds_ibdev->list);
 247         up_write(&rds_ib_devices_lock);
 248
 249         /*
 250          * This synchronize rcu is waiting for readers of both the ib
 251          * client data and the devices list to finish before we drop
 252          * both of those references.
 253          */
 254         synchronize_rcu();
 255         rds_ib_dev_put(rds_ibdev);
 256         rds_ib_dev_put(rds_ibdev);
 257 }
 258
 259 struct ib_client rds_ib_client = {
 260         .name   = "rds_ib",
 261         .add    = rds_ib_add_one,
 262         .remove = rds_ib_remove_one
 263 };
 264
 265 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 266                                     void *buffer)
 267 {
 268         struct rds_info_rdma_connection *iinfo = buffer;
 269         struct rds_ib_connection *ic;
 270
 271         /* We will only ever look at IB transports */
 272         if (conn->c_trans != &rds_ib_transport)
 273                 return 0;
 274
 275         iinfo->src_addr = conn->c_laddr;
 276         iinfo->dst_addr = conn->c_faddr;
 277
 278         memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 279         memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
 280         if (rds_conn_state(conn) == RDS_CONN_UP) {
 281                 struct rds_ib_device *rds_ibdev;
 282                 struct rdma_dev_addr *dev_addr;
 283
 284                 ic = conn->c_transport_data;
 285                 dev_addr = &ic->i_cm_id->route.addr.dev_addr;
 286
 287                 rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
 288                 rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
 289
 290                 rds_ibdev = ic->rds_ibdev;
 291                 iinfo->max_send_wr = ic->i_send_ring.w_nr;
 292                 iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
 293                 iinfo->max_send_sge = rds_ibdev->max_sge;
 294                 rds_ib_get_mr_info(rds_ibdev, iinfo);
 295         }
 296         return 1;
 297 }
 298
 299 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 300                            struct rds_info_iterator *iter,
 301                            struct rds_info_lengths *lens)
 302 {
 303         rds_for_each_conn_info(sock, len, iter, lens,
 304                                 rds_ib_conn_info_visitor,
 305                                 sizeof(struct rds_info_rdma_connection));
 306 }
 307
 308
 309 /*
 310  * Early RDS/IB was built to only bind to an address if there is an IPoIB
 311  * device with that address set.
 312  *
 313  * If it were me, I'd advocate for something more flexible.  Sending and
 314  * receiving should be device-agnostic.  Transports would try and maintain
 315  * connections between peers who have messages queued.  Userspace would be
 316  * allowed to influence which paths have priority.  We could call userspace
 317  * asserting this policy "routing".
 318  */
 319 static int rds_ib_laddr_check(__be32 addr)
 320 {
 321         int ret;
 322         struct rdma_cm_id *cm_id;
 323         struct sockaddr_in sin;
 324
 325         /* Create a CMA ID and try to bind it. This catches both
 326          * IB and iWARP capable NICs.
 327          */
 328         cm_id = rdma_create_id(NULL, NULL, RDMA_PS_TCP, IB_QPT_RC);
 329         if (IS_ERR(cm_id))
 330                 return PTR_ERR(cm_id);
 331
 332         memset(&sin, 0, sizeof(sin));
 333         sin.sin_family = AF_INET;
 334         sin.sin_addr.s_addr = addr;
 335
 336         /* rdma_bind_addr will only succeed for IB & iWARP devices */
 337         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 338         /* due to this, we will claim to support iWARP devices unless we
 339            check node_type. */
 340         if (ret || 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 }
 368
 369 struct rds_transport rds_ib_transport = {
 370         .laddr_check            = rds_ib_laddr_check,
 371         .xmit_complete          = rds_ib_xmit_complete,
 372         .xmit                   = rds_ib_xmit,
 373         .xmit_rdma              = rds_ib_xmit_rdma,
 374         .xmit_atomic            = rds_ib_xmit_atomic,
 375         .recv                   = rds_ib_recv,
 376         .conn_alloc             = rds_ib_conn_alloc,
 377         .conn_free              = rds_ib_conn_free,
 378         .conn_connect           = rds_ib_conn_connect,
 379         .conn_shutdown          = rds_ib_conn_shutdown,
 380         .inc_copy_to_user       = rds_ib_inc_copy_to_user,
 381         .inc_free               = rds_ib_inc_free,
 382         .cm_initiate_connect    = rds_ib_cm_initiate_connect,
 383         .cm_handle_connect      = rds_ib_cm_handle_connect,
 384         .cm_connect_complete    = rds_ib_cm_connect_complete,
 385         .stats_info_copy        = rds_ib_stats_info_copy,
 386         .exit                   = rds_ib_exit,
 387         .get_mr                 = rds_ib_get_mr,
 388         .sync_mr                = rds_ib_sync_mr,
 389         .free_mr                = rds_ib_free_mr,
 390         .flush_mrs              = rds_ib_flush_mrs,
 391         .t_owner                = THIS_MODULE,
 392         .t_name                 = "infiniband",
 393         .t_type                 = RDS_TRANS_IB
 394 };
 395
 396 int rds_ib_init(void)
 397 {
 398         int ret;
 399
 400         INIT_LIST_HEAD(&rds_ib_devices);
 401
 402         ret = ib_register_client(&rds_ib_client);
 403         if (ret)
 404                 goto out;
 405
 406         ret = rds_ib_sysctl_init();
 407         if (ret)
 408                 goto out_ibreg;
 409
 410         ret = rds_ib_recv_init();
 411         if (ret)
 412                 goto out_sysctl;
 413
 414         ret = rds_trans_register(&rds_ib_transport);
 415         if (ret)
 416                 goto out_recv;
 417
 418         rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 419
 420         goto out;
 421
 422 out_recv:
 423         rds_ib_recv_exit();
 424 out_sysctl:
 425         rds_ib_sysctl_exit();
 426 out_ibreg:
 427         rds_ib_unregister_client();
 428 out:
 429         return ret;
 430 }
 431
 432 MODULE_LICENSE("GPL");
 433