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->mr)
 103                 ib_dereg_mr(rds_ibdev->mr);
 104         if (rds_ibdev->pd)
 105                 ib_dealloc_pd(rds_ibdev->pd);
 106
 107         list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
 108                 list_del(&i_ipaddr->list);
 109                 kfree(i_ipaddr);
 110         }
 111
 112         kfree(rds_ibdev);
 113 }
 114
 115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
 116 {
 117         BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
 118         if (atomic_dec_and_test(&rds_ibdev->refcount))
 119                 queue_work(rds_wq, &rds_ibdev->free_work);
 120 }
 121
 122 static void rds_ib_add_one(struct ib_device *device)
 123 {
 124         struct rds_ib_device *rds_ibdev;
 125         struct ib_device_attr *dev_attr;
 126
 127         /* Only handle IB (no iWARP) devices */
 128         if (device->node_type != RDMA_NODE_IB_CA)
 129                 return;
 130
 131         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
 132         if (!dev_attr)
 133                 return;
 134
 135         if (ib_query_device(device, dev_attr)) {
 136                 rdsdebug("Query device failed for %s\n", device->name);
 137                 goto free_attr;
 138         }
 139
 140         rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
 141                                  ibdev_to_node(device));
 142         if (!rds_ibdev)
 143                 goto free_attr;
 144
 145         spin_lock_init(&rds_ibdev->spinlock);
 146         atomic_set(&rds_ibdev->refcount, 1);
 147         INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 148
 149         rds_ibdev->max_wrs = dev_attr->max_qp_wr;
 150         rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
 151
 152         rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
 153         rds_ibdev->max_fmrs = dev_attr->max_fmr ?
 154                         min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
 155                         fmr_pool_size;
 156
 157         rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
 158         rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
 159
 160         rds_ibdev->dev = device;
 161         rds_ibdev->pd = ib_alloc_pd(device);
 162         if (IS_ERR(rds_ibdev->pd)) {
 163                 rds_ibdev->pd = NULL;
 164                 goto put_dev;
 165         }
 166
 167         rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE);
 168         if (IS_ERR(rds_ibdev->mr)) {
 169                 rds_ibdev->mr = NULL;
 170                 goto put_dev;
 171         }
 172
 173         rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
 174         if (IS_ERR(rds_ibdev->mr_pool)) {
 175                 rds_ibdev->mr_pool = NULL;
 176                 goto put_dev;
 177         }
 178
 179         INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
 180         INIT_LIST_HEAD(&rds_ibdev->conn_list);
 181
 182         down_write(&rds_ib_devices_lock);
 183         list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 184         up_write(&rds_ib_devices_lock);
 185         atomic_inc(&rds_ibdev->refcount);
 186
 187         ib_set_client_data(device, &rds_ib_client, rds_ibdev);
 188         atomic_inc(&rds_ibdev->refcount);
 189
 190         rds_ib_nodev_connect();
 191
 192 put_dev:
 193         rds_ib_dev_put(rds_ibdev);
 194 free_attr:
 195         kfree(dev_attr);
 196 }
 197
 198 /*
 199  * New connections use this to find the device to associate with the
 200  * connection.  It's not in the fast path so we're not concerned about the
 201  * performance of the IB call.  (As of this writing, it uses an interrupt
 202  * blocking spinlock to serialize walking a per-device list of all registered
 203  * clients.)
 204  *
 205  * RCU is used to handle incoming connections racing with device teardown.
 206  * Rather than use a lock to serialize removal from the client_data and
 207  * getting a new reference, we use an RCU grace period.  The destruction
 208  * path removes the device from client_data and then waits for all RCU
 209  * readers to finish.
 210  *
 211  * A new connection can get NULL from this if its arriving on a
 212  * device that is in the process of being removed.
 213  */
 214 struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
 215 {
 216         struct rds_ib_device *rds_ibdev;
 217
 218         rcu_read_lock();
 219         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 220         if (rds_ibdev)
 221                 atomic_inc(&rds_ibdev->refcount);
 222         rcu_read_unlock();
 223         return rds_ibdev;
 224 }
 225
 226 /*
 227  * The IB stack is letting us know that a device is going away.  This can
 228  * happen if the underlying HCA driver is removed or if PCI hotplug is removing
 229  * the pci function, for example.
 230  *
 231  * This can be called at any time and can be racing with any other RDS path.
 232  */
 233 static void rds_ib_remove_one(struct ib_device *device)
 234 {
 235         struct rds_ib_device *rds_ibdev;
 236
 237         rds_ibdev = ib_get_client_data(device, &rds_ib_client);
 238         if (!rds_ibdev)
 239                 return;
 240
 241         rds_ib_dev_shutdown(rds_ibdev);
 242
 243         /* stop connection attempts from getting a reference to this device. */
 244         ib_set_client_data(device, &rds_ib_client, NULL);
 245
 246         down_write(&rds_ib_devices_lock);
 247         list_del_rcu(&rds_ibdev->list);
 248         up_write(&rds_ib_devices_lock);
 249
 250         /*
 251          * This synchronize rcu is waiting for readers of both the ib
 252          * client data and the devices list to finish before we drop
 253          * both of those references.
 254          */
 255         synchronize_rcu();
 256         rds_ib_dev_put(rds_ibdev);
 257         rds_ib_dev_put(rds_ibdev);
 258 }
 259
 260 struct ib_client rds_ib_client = {
 261         .name   = "rds_ib",
 262         .add    = rds_ib_add_one,
 263         .remove = rds_ib_remove_one
 264 };
 265
 266 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
 267                                     void *buffer)
 268 {
 269         struct rds_info_rdma_connection *iinfo = buffer;
 270         struct rds_ib_connection *ic;
 271
 272         /* We will only ever look at IB transports */
 273         if (conn->c_trans != &rds_ib_transport)
 274                 return 0;
 275
 276         iinfo->src_addr = conn->c_laddr;
 277         iinfo->dst_addr = conn->c_faddr;
 278
 279         memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
 280         memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
 281         if (rds_conn_state(conn) == RDS_CONN_UP) {
 282                 struct rds_ib_device *rds_ibdev;
 283                 struct rdma_dev_addr *dev_addr;
 284
 285                 ic = conn->c_transport_data;
 286                 dev_addr = &ic->i_cm_id->route.addr.dev_addr;
 287
 288                 rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
 289                 rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
 290
 291                 rds_ibdev = ic->rds_ibdev;
 292                 iinfo->max_send_wr = ic->i_send_ring.w_nr;
 293                 iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
 294                 iinfo->max_send_sge = rds_ibdev->max_sge;
 295                 rds_ib_get_mr_info(rds_ibdev, iinfo);
 296         }
 297         return 1;
 298 }
 299
 300 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
 301                            struct rds_info_iterator *iter,
 302                            struct rds_info_lengths *lens)
 303 {
 304         rds_for_each_conn_info(sock, len, iter, lens,
 305                                 rds_ib_conn_info_visitor,
 306                                 sizeof(struct rds_info_rdma_connection));
 307 }
 308
 309
 310 /*
 311  * Early RDS/IB was built to only bind to an address if there is an IPoIB
 312  * device with that address set.
 313  *
 314  * If it were me, I'd advocate for something more flexible.  Sending and
 315  * receiving should be device-agnostic.  Transports would try and maintain
 316  * connections between peers who have messages queued.  Userspace would be
 317  * allowed to influence which paths have priority.  We could call userspace
 318  * asserting this policy "routing".
 319  */
 320 static int rds_ib_laddr_check(__be32 addr)
 321 {
 322         int ret;
 323         struct rdma_cm_id *cm_id;
 324         struct sockaddr_in sin;
 325
 326         /* Create a CMA ID and try to bind it. This catches both
 327          * IB and iWARP capable NICs.
 328          */
 329         cm_id = rdma_create_id(NULL, NULL, RDMA_PS_TCP, IB_QPT_RC);
 330         if (IS_ERR(cm_id))
 331                 return PTR_ERR(cm_id);
 332
 333         memset(&sin, 0, sizeof(sin));
 334         sin.sin_family = AF_INET;
 335         sin.sin_addr.s_addr = addr;
 336
 337         /* rdma_bind_addr will only succeed for IB & iWARP devices */
 338         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 339         /* due to this, we will claim to support iWARP devices unless we
 340            check node_type. */
 341         if (ret || cm_id->device->node_type != RDMA_NODE_IB_CA)
 342                 ret = -EADDRNOTAVAIL;
 343
 344         rdsdebug("addr %pI4 ret %d node type %d\n",
 345                 &addr, ret,
 346                 cm_id->device ? cm_id->device->node_type : -1);
 347
 348         rdma_destroy_id(cm_id);
 349
 350         return ret;
 351 }
 352
 353 static void rds_ib_unregister_client(void)
 354 {
 355         ib_unregister_client(&rds_ib_client);
 356         /* wait for rds_ib_dev_free() to complete */
 357         flush_workqueue(rds_wq);
 358 }
 359
 360 void rds_ib_exit(void)
 361 {
 362         rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 363         rds_ib_unregister_client();
 364         rds_ib_destroy_nodev_conns();
 365         rds_ib_sysctl_exit();
 366         rds_ib_recv_exit();
 367         rds_trans_unregister(&rds_ib_transport);
 368 }
 369
 370 struct rds_transport rds_ib_transport = {
 371         .laddr_check            = rds_ib_laddr_check,
 372         .xmit_complete          = rds_ib_xmit_complete,
 373         .xmit                   = rds_ib_xmit,
 374         .xmit_rdma              = rds_ib_xmit_rdma,
 375         .xmit_atomic            = rds_ib_xmit_atomic,
 376         .recv                   = rds_ib_recv,
 377         .conn_alloc             = rds_ib_conn_alloc,
 378         .conn_free              = rds_ib_conn_free,
 379         .conn_connect           = rds_ib_conn_connect,
 380         .conn_shutdown          = rds_ib_conn_shutdown,
 381         .inc_copy_to_user       = rds_ib_inc_copy_to_user,
 382         .inc_free               = rds_ib_inc_free,
 383         .cm_initiate_connect    = rds_ib_cm_initiate_connect,
 384         .cm_handle_connect      = rds_ib_cm_handle_connect,
 385         .cm_connect_complete    = rds_ib_cm_connect_complete,
 386         .stats_info_copy        = rds_ib_stats_info_copy,
 387         .exit                   = rds_ib_exit,
 388         .get_mr                 = rds_ib_get_mr,
 389         .sync_mr                = rds_ib_sync_mr,
 390         .free_mr                = rds_ib_free_mr,
 391         .flush_mrs              = rds_ib_flush_mrs,
 392         .t_owner                = THIS_MODULE,
 393         .t_name                 = "infiniband",
 394         .t_type                 = RDS_TRANS_IB
 395 };
 396
 397 int rds_ib_init(void)
 398 {
 399         int ret;
 400
 401         INIT_LIST_HEAD(&rds_ib_devices);
 402
 403         ret = ib_register_client(&rds_ib_client);
 404         if (ret)
 405                 goto out;
 406
 407         ret = rds_ib_sysctl_init();
 408         if (ret)
 409                 goto out_ibreg;
 410
 411         ret = rds_ib_recv_init();
 412         if (ret)
 413                 goto out_sysctl;
 414
 415         ret = rds_trans_register(&rds_ib_transport);
 416         if (ret)
 417                 goto out_recv;
 418
 419         rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
 420
 421         goto out;
 422
 423 out_recv:
 424         rds_ib_recv_exit();
 425 out_sysctl:
 426         rds_ib_sysctl_exit();
 427 out_ibreg:
 428         rds_ib_unregister_client();
 429 out:
 430         return ret;
 431 }
 432
 433 MODULE_LICENSE("GPL");
 434