net/rds/ib_rdma.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/slab.h>
  35 #include <linux/rculist.h>
  36 #include <linux/llist.h>
  37
  38 #include "ib_mr.h"
  39
  40 struct workqueue_struct *rds_ib_mr_wq;
  41
  42 static DEFINE_PER_CPU(unsigned long, clean_list_grace);
  43 #define CLEAN_LIST_BUSY_BIT 0
  44
  45 static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
  46 {
  47         struct rds_ib_device *rds_ibdev;
  48         struct rds_ib_ipaddr *i_ipaddr;
  49
  50         rcu_read_lock();
  51         list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
  52                 list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
  53                         if (i_ipaddr->ipaddr == ipaddr) {
  54                                 atomic_inc(&rds_ibdev->refcount);
  55                                 rcu_read_unlock();
  56                                 return rds_ibdev;
  57                         }
  58                 }
  59         }
  60         rcu_read_unlock();
  61
  62         return NULL;
  63 }
  64
  65 static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
  66 {
  67         struct rds_ib_ipaddr *i_ipaddr;
  68
  69         i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
  70         if (!i_ipaddr)
  71                 return -ENOMEM;
  72
  73         i_ipaddr->ipaddr = ipaddr;
  74
  75         spin_lock_irq(&rds_ibdev->spinlock);
  76         list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
  77         spin_unlock_irq(&rds_ibdev->spinlock);
  78
  79         return 0;
  80 }
  81
  82 static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
  83 {
  84         struct rds_ib_ipaddr *i_ipaddr;
  85         struct rds_ib_ipaddr *to_free = NULL;
  86
  87
  88         spin_lock_irq(&rds_ibdev->spinlock);
  89         list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
  90                 if (i_ipaddr->ipaddr == ipaddr) {
  91                         list_del_rcu(&i_ipaddr->list);
  92                         to_free = i_ipaddr;
  93                         break;
  94                 }
  95         }
  96         spin_unlock_irq(&rds_ibdev->spinlock);
  97
  98         if (to_free)
  99                 kfree_rcu(to_free, rcu);
 100 }
 101
 102 int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
 103 {
 104         struct rds_ib_device *rds_ibdev_old;
 105
 106         rds_ibdev_old = rds_ib_get_device(ipaddr);
 107         if (!rds_ibdev_old)
 108                 return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
 109
 110         if (rds_ibdev_old != rds_ibdev) {
 111                 rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
 112                 rds_ib_dev_put(rds_ibdev_old);
 113                 return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
 114         }
 115         rds_ib_dev_put(rds_ibdev_old);
 116
 117         return 0;
 118 }
 119
 120 void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
 121 {
 122         struct rds_ib_connection *ic = conn->c_transport_data;
 123
 124         /* conn was previously on the nodev_conns_list */
 125         spin_lock_irq(&ib_nodev_conns_lock);
 126         BUG_ON(list_empty(&ib_nodev_conns));
 127         BUG_ON(list_empty(&ic->ib_node));
 128         list_del(&ic->ib_node);
 129
 130         spin_lock(&rds_ibdev->spinlock);
 131         list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
 132         spin_unlock(&rds_ibdev->spinlock);
 133         spin_unlock_irq(&ib_nodev_conns_lock);
 134
 135         ic->rds_ibdev = rds_ibdev;
 136         atomic_inc(&rds_ibdev->refcount);
 137 }
 138
 139 void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
 140 {
 141         struct rds_ib_connection *ic = conn->c_transport_data;
 142
 143         /* place conn on nodev_conns_list */
 144         spin_lock(&ib_nodev_conns_lock);
 145
 146         spin_lock_irq(&rds_ibdev->spinlock);
 147         BUG_ON(list_empty(&ic->ib_node));
 148         list_del(&ic->ib_node);
 149         spin_unlock_irq(&rds_ibdev->spinlock);
 150
 151         list_add_tail(&ic->ib_node, &ib_nodev_conns);
 152
 153         spin_unlock(&ib_nodev_conns_lock);
 154
 155         ic->rds_ibdev = NULL;
 156         rds_ib_dev_put(rds_ibdev);
 157 }
 158
 159 void rds_ib_destroy_nodev_conns(void)
 160 {
 161         struct rds_ib_connection *ic, *_ic;
 162         LIST_HEAD(tmp_list);
 163
 164         /* avoid calling conn_destroy with irqs off */
 165         spin_lock_irq(&ib_nodev_conns_lock);
 166         list_splice(&ib_nodev_conns, &tmp_list);
 167         spin_unlock_irq(&ib_nodev_conns_lock);
 168
 169         list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
 170                 rds_conn_destroy(ic->conn);
 171 }
 172
 173 void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
 174 {
 175         struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
 176
 177         iinfo->rdma_mr_max = pool_1m->max_items;
 178         iinfo->rdma_mr_size = pool_1m->fmr_attr.max_pages;
 179 }
 180
 181 struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool)
 182 {
 183         struct rds_ib_mr *ibmr = NULL;
 184         struct llist_node *ret;
 185         unsigned long *flag;
 186
 187         preempt_disable();
 188         flag = this_cpu_ptr(&clean_list_grace);
 189         set_bit(CLEAN_LIST_BUSY_BIT, flag);
 190         ret = llist_del_first(&pool->clean_list);
 191         if (ret) {
 192                 ibmr = llist_entry(ret, struct rds_ib_mr, llnode);
 193                 if (pool->pool_type == RDS_IB_MR_8K_POOL)
 194                         rds_ib_stats_inc(s_ib_rdma_mr_8k_reused);
 195                 else
 196                         rds_ib_stats_inc(s_ib_rdma_mr_1m_reused);
 197         }
 198
 199         clear_bit(CLEAN_LIST_BUSY_BIT, flag);
 200         preempt_enable();
 201         return ibmr;
 202 }
 203
 204 static inline void wait_clean_list_grace(void)
 205 {
 206         int cpu;
 207         unsigned long *flag;
 208
 209         for_each_online_cpu(cpu) {
 210                 flag = &per_cpu(clean_list_grace, cpu);
 211                 while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
 212                         cpu_relax();
 213         }
 214 }
 215
 216 void rds_ib_sync_mr(void *trans_private, int direction)
 217 {
 218         struct rds_ib_mr *ibmr = trans_private;
 219         struct rds_ib_device *rds_ibdev = ibmr->device;
 220
 221         switch (direction) {
 222         case DMA_FROM_DEVICE:
 223                 ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
 224                         ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
 225                 break;
 226         case DMA_TO_DEVICE:
 227                 ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
 228                         ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
 229                 break;
 230         }
 231 }
 232
 233 void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
 234 {
 235         struct rds_ib_device *rds_ibdev = ibmr->device;
 236
 237         if (ibmr->sg_dma_len) {
 238                 ib_dma_unmap_sg(rds_ibdev->dev,
 239                                 ibmr->sg, ibmr->sg_len,
 240                                 DMA_BIDIRECTIONAL);
 241                 ibmr->sg_dma_len = 0;
 242         }
 243
 244         /* Release the s/g list */
 245         if (ibmr->sg_len) {
 246                 unsigned int i;
 247
 248                 for (i = 0; i < ibmr->sg_len; ++i) {
 249                         struct page *page = sg_page(&ibmr->sg[i]);
 250
 251                         /* FIXME we need a way to tell a r/w MR
 252                          * from a r/o MR */
 253                         WARN_ON(!page->mapping && irqs_disabled());
 254                         set_page_dirty(page);
 255                         put_page(page);
 256                 }
 257                 kfree(ibmr->sg);
 258
 259                 ibmr->sg = NULL;
 260                 ibmr->sg_len = 0;
 261         }
 262 }
 263
 264 void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
 265 {
 266         unsigned int pinned = ibmr->sg_len;
 267
 268         __rds_ib_teardown_mr(ibmr);
 269         if (pinned) {
 270                 struct rds_ib_mr_pool *pool = ibmr->pool;
 271
 272                 atomic_sub(pinned, &pool->free_pinned);
 273         }
 274 }
 275
 276 static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
 277 {
 278         unsigned int item_count;
 279
 280         item_count = atomic_read(&pool->item_count);
 281         if (free_all)
 282                 return item_count;
 283
 284         return 0;
 285 }
 286
 287 /*
 288  * given an llist of mrs, put them all into the list_head for more processing
 289  */
 290 static unsigned int llist_append_to_list(struct llist_head *llist,
 291                                          struct list_head *list)
 292 {
 293         struct rds_ib_mr *ibmr;
 294         struct llist_node *node;
 295         struct llist_node *next;
 296         unsigned int count = 0;
 297
 298         node = llist_del_all(llist);
 299         while (node) {
 300                 next = node->next;
 301                 ibmr = llist_entry(node, struct rds_ib_mr, llnode);
 302                 list_add_tail(&ibmr->unmap_list, list);
 303                 node = next;
 304                 count++;
 305         }
 306         return count;
 307 }
 308
 309 /*
 310  * this takes a list head of mrs and turns it into linked llist nodes
 311  * of clusters.  Each cluster has linked llist nodes of
 312  * MR_CLUSTER_SIZE mrs that are ready for reuse.
 313  */
 314 static void list_to_llist_nodes(struct rds_ib_mr_pool *pool,
 315                                 struct list_head *list,
 316                                 struct llist_node **nodes_head,
 317                                 struct llist_node **nodes_tail)
 318 {
 319         struct rds_ib_mr *ibmr;
 320         struct llist_node *cur = NULL;
 321         struct llist_node **next = nodes_head;
 322
 323         list_for_each_entry(ibmr, list, unmap_list) {
 324                 cur = &ibmr->llnode;
 325                 *next = cur;
 326                 next = &cur->next;
 327         }
 328         *next = NULL;
 329         *nodes_tail = cur;
 330 }
 331
 332 /*
 333  * Flush our pool of MRs.
 334  * At a minimum, all currently unused MRs are unmapped.
 335  * If the number of MRs allocated exceeds the limit, we also try
 336  * to free as many MRs as needed to get back to this limit.
 337  */
 338 int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
 339                          int free_all, struct rds_ib_mr **ibmr_ret)
 340 {
 341         struct rds_ib_mr *ibmr;
 342         struct llist_node *clean_nodes;
 343         struct llist_node *clean_tail;
 344         LIST_HEAD(unmap_list);
 345         unsigned long unpinned = 0;
 346         unsigned int nfreed = 0, dirty_to_clean = 0, free_goal;
 347
 348         if (pool->pool_type == RDS_IB_MR_8K_POOL)
 349                 rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_flush);
 350         else
 351                 rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_flush);
 352
 353         if (ibmr_ret) {
 354                 DEFINE_WAIT(wait);
 355                 while (!mutex_trylock(&pool->flush_lock)) {
 356                         ibmr = rds_ib_reuse_mr(pool);
 357                         if (ibmr) {
 358                                 *ibmr_ret = ibmr;
 359                                 finish_wait(&pool->flush_wait, &wait);
 360                                 goto out_nolock;
 361                         }
 362
 363                         prepare_to_wait(&pool->flush_wait, &wait,
 364                                         TASK_UNINTERRUPTIBLE);
 365                         if (llist_empty(&pool->clean_list))
 366                                 schedule();
 367
 368                         ibmr = rds_ib_reuse_mr(pool);
 369                         if (ibmr) {
 370                                 *ibmr_ret = ibmr;
 371                                 finish_wait(&pool->flush_wait, &wait);
 372                                 goto out_nolock;
 373                         }
 374                 }
 375                 finish_wait(&pool->flush_wait, &wait);
 376         } else
 377                 mutex_lock(&pool->flush_lock);
 378
 379         if (ibmr_ret) {
 380                 ibmr = rds_ib_reuse_mr(pool);
 381                 if (ibmr) {
 382                         *ibmr_ret = ibmr;
 383                         goto out;
 384                 }
 385         }
 386
 387         /* Get the list of all MRs to be dropped. Ordering matters -
 388          * we want to put drop_list ahead of free_list.
 389          */
 390         dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list);
 391         dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list);
 392         if (free_all)
 393                 llist_append_to_list(&pool->clean_list, &unmap_list);
 394
 395         free_goal = rds_ib_flush_goal(pool, free_all);
 396
 397         if (list_empty(&unmap_list))
 398                 goto out;
 399
 400         if (pool->use_fastreg)
 401                 rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
 402         else
 403                 rds_ib_unreg_fmr(&unmap_list, &nfreed, &unpinned, free_goal);
 404
 405         if (!list_empty(&unmap_list)) {
 406                 /* we have to make sure that none of the things we're about
 407                  * to put on the clean list would race with other cpus trying
 408                  * to pull items off.  The llist would explode if we managed to
 409                  * remove something from the clean list and then add it back again
 410                  * while another CPU was spinning on that same item in llist_del_first.
 411                  *
 412                  * This is pretty unlikely, but just in case  wait for an llist grace period
 413                  * here before adding anything back into the clean list.
 414                  */
 415                 wait_clean_list_grace();
 416
 417                 list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail);
 418                 if (ibmr_ret)
 419                         *ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode);
 420
 421                 /* more than one entry in llist nodes */
 422                 if (clean_nodes->next)
 423                         llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list);
 424
 425         }
 426
 427         atomic_sub(unpinned, &pool->free_pinned);
 428         atomic_sub(dirty_to_clean, &pool->dirty_count);
 429         atomic_sub(nfreed, &pool->item_count);
 430
 431 out:
 432         mutex_unlock(&pool->flush_lock);
 433         if (waitqueue_active(&pool->flush_wait))
 434                 wake_up(&pool->flush_wait);
 435 out_nolock:
 436         return 0;
 437 }
 438
 439 struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *pool)
 440 {
 441         struct rds_ib_mr *ibmr = NULL;
 442         int iter = 0;
 443
 444         if (atomic_read(&pool->dirty_count) >= pool->max_items_soft / 10)
 445                 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
 446
 447         while (1) {
 448                 ibmr = rds_ib_reuse_mr(pool);
 449                 if (ibmr)
 450                         return ibmr;
 451
 452                 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
 453                         break;
 454
 455                 atomic_dec(&pool->item_count);
 456
 457                 if (++iter > 2) {
 458                         if (pool->pool_type == RDS_IB_MR_8K_POOL)
 459                                 rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_depleted);
 460                         else
 461                                 rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_depleted);
 462                         return ERR_PTR(-EAGAIN);
 463                 }
 464
 465                 /* We do have some empty MRs. Flush them out. */
 466                 if (pool->pool_type == RDS_IB_MR_8K_POOL)
 467                         rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_wait);
 468                 else
 469                         rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_wait);
 470
 471                 rds_ib_flush_mr_pool(pool, 0, &ibmr);
 472                 if (ibmr)
 473                         return ibmr;
 474         }
 475
 476         return ibmr;
 477 }
 478
 479 static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
 480 {
 481         struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
 482
 483         rds_ib_flush_mr_pool(pool, 0, NULL);
 484 }
 485
 486 void rds_ib_free_mr(void *trans_private, int invalidate)
 487 {
 488         struct rds_ib_mr *ibmr = trans_private;
 489         struct rds_ib_mr_pool *pool = ibmr->pool;
 490         struct rds_ib_device *rds_ibdev = ibmr->device;
 491
 492         rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
 493
 494         /* Return it to the pool's free list */
 495         if (rds_ibdev->use_fastreg)
 496                 rds_ib_free_frmr_list(ibmr);
 497         else
 498                 rds_ib_free_fmr_list(ibmr);
 499
 500         atomic_add(ibmr->sg_len, &pool->free_pinned);
 501         atomic_inc(&pool->dirty_count);
 502
 503         /* If we've pinned too many pages, request a flush */
 504         if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
 505             atomic_read(&pool->dirty_count) >= pool->max_items / 5)
 506                 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
 507
 508         if (invalidate) {
 509                 if (likely(!in_interrupt())) {
 510                         rds_ib_flush_mr_pool(pool, 0, NULL);
 511                 } else {
 512                         /* We get here if the user created a MR marked
 513                          * as use_once and invalidate at the same time.
 514                          */
 515                         queue_delayed_work(rds_ib_mr_wq,
 516                                            &pool->flush_worker, 10);
 517                 }
 518         }
 519
 520         rds_ib_dev_put(rds_ibdev);
 521 }
 522
 523 void rds_ib_flush_mrs(void)
 524 {
 525         struct rds_ib_device *rds_ibdev;
 526
 527         down_read(&rds_ib_devices_lock);
 528         list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
 529                 if (rds_ibdev->mr_8k_pool)
 530                         rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL);
 531
 532                 if (rds_ibdev->mr_1m_pool)
 533                         rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL);
 534         }
 535         up_read(&rds_ib_devices_lock);
 536 }
 537
 538 void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
 539                     struct rds_sock *rs, u32 *key_ret)
 540 {
 541         struct rds_ib_device *rds_ibdev;
 542         struct rds_ib_mr *ibmr = NULL;
 543         struct rds_ib_connection *ic = rs->rs_conn->c_transport_data;
 544         int ret;
 545
 546         rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
 547         if (!rds_ibdev) {
 548                 ret = -ENODEV;
 549                 goto out;
 550         }
 551
 552         if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) {
 553                 ret = -ENODEV;
 554                 goto out;
 555         }
 556
 557         if (rds_ibdev->use_fastreg)
 558                 ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
 559         else
 560                 ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret);
 561         if (ibmr)
 562                 rds_ibdev = NULL;
 563
 564  out:
 565         if (!ibmr)
 566                 pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
 567
 568         if (rds_ibdev)
 569                 rds_ib_dev_put(rds_ibdev);
 570
 571         return ibmr;
 572 }
 573
 574 void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
 575 {
 576         cancel_delayed_work_sync(&pool->flush_worker);
 577         rds_ib_flush_mr_pool(pool, 1, NULL);
 578         WARN_ON(atomic_read(&pool->item_count));
 579         WARN_ON(atomic_read(&pool->free_pinned));
 580         kfree(pool);
 581 }
 582
 583 struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev,
 584                                              int pool_type)
 585 {
 586         struct rds_ib_mr_pool *pool;
 587
 588         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
 589         if (!pool)
 590                 return ERR_PTR(-ENOMEM);
 591
 592         pool->pool_type = pool_type;
 593         init_llist_head(&pool->free_list);
 594         init_llist_head(&pool->drop_list);
 595         init_llist_head(&pool->clean_list);
 596         mutex_init(&pool->flush_lock);
 597         init_waitqueue_head(&pool->flush_wait);
 598         INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
 599
 600         if (pool_type == RDS_IB_MR_1M_POOL) {
 601                 /* +1 allows for unaligned MRs */
 602                 pool->fmr_attr.max_pages = RDS_MR_1M_MSG_SIZE + 1;
 603                 pool->max_items = RDS_MR_1M_POOL_SIZE;
 604         } else {
 605                 /* pool_type == RDS_IB_MR_8K_POOL */
 606                 pool->fmr_attr.max_pages = RDS_MR_8K_MSG_SIZE + 1;
 607                 pool->max_items = RDS_MR_8K_POOL_SIZE;
 608         }
 609
 610         pool->max_free_pinned = pool->max_items * pool->fmr_attr.max_pages / 4;
 611         pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
 612         pool->fmr_attr.page_shift = PAGE_SHIFT;
 613         pool->max_items_soft = rds_ibdev->max_mrs * 3 / 4;
 614         pool->use_fastreg = rds_ibdev->use_fastreg;
 615
 616         return pool;
 617 }
 618
 619 int rds_ib_mr_init(void)
 620 {
 621         rds_ib_mr_wq = alloc_workqueue("rds_mr_flushd", WQ_MEM_RECLAIM, 0);
 622         if (!rds_ib_mr_wq)
 623                 return -ENOMEM;
 624         return 0;
 625 }
 626
 627 /* By the time this is called all the IB devices should have been torn down and
 628  * had their pools freed.  As each pool is freed its work struct is waited on,
 629  * so the pool flushing work queue should be idle by the time we get here.
 630  */
 631 void rds_ib_mr_exit(void)
 632 {
 633         destroy_workqueue(rds_ib_mr_wq);
 634 }