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