net/rds/iw_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/ratelimit.h>
  36
  37 #include "rds.h"
  38 #include "iw.h"
  39
  40
  41 /*
  42  * This is stored as mr->r_trans_private.
  43  */
  44 struct rds_iw_mr {
  45         struct rds_iw_device    *device;
  46         struct rds_iw_mr_pool   *pool;
  47         struct rdma_cm_id       *cm_id;
  48
  49         struct ib_mr    *mr;
  50         struct ib_fast_reg_page_list *page_list;
  51
  52         struct rds_iw_mapping   mapping;
  53         unsigned char           remap_count;
  54 };
  55
  56 /*
  57  * Our own little MR pool
  58  */
  59 struct rds_iw_mr_pool {
  60         struct rds_iw_device    *device;                /* back ptr to the device that owns us */
  61
  62         struct mutex            flush_lock;             /* serialize fmr invalidate */
  63         struct work_struct      flush_worker;           /* flush worker */
  64
  65         spinlock_t              list_lock;              /* protect variables below */
  66         atomic_t                item_count;             /* total # of MRs */
  67         atomic_t                dirty_count;            /* # dirty of MRs */
  68         struct list_head        dirty_list;             /* dirty mappings */
  69         struct list_head        clean_list;             /* unused & unamapped MRs */
  70         atomic_t                free_pinned;            /* memory pinned by free MRs */
  71         unsigned long           max_message_size;       /* in pages */
  72         unsigned long           max_items;
  73         unsigned long           max_items_soft;
  74         unsigned long           max_free_pinned;
  75         int                     max_pages;
  76 };
  77
  78 static void rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all);
  79 static void rds_iw_mr_pool_flush_worker(struct work_struct *work);
  80 static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  81 static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
  82                           struct rds_iw_mr *ibmr,
  83                           struct scatterlist *sg, unsigned int nents);
  84 static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  85 static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
  86                         struct list_head *unmap_list,
  87                         struct list_head *kill_list,
  88                         int *unpinned);
  89 static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  90
  91 static int rds_iw_get_device(struct sockaddr_in *src, struct sockaddr_in *dst,
  92                              struct rds_iw_device **rds_iwdev,
  93                              struct rdma_cm_id **cm_id)
  94 {
  95         struct rds_iw_device *iwdev;
  96         struct rds_iw_cm_id *i_cm_id;
  97
  98         *rds_iwdev = NULL;
  99         *cm_id = NULL;
 100
 101         list_for_each_entry(iwdev, &rds_iw_devices, list) {
 102                 spin_lock_irq(&iwdev->spinlock);
 103                 list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) {
 104                         struct sockaddr_in *src_addr, *dst_addr;
 105
 106                         src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr;
 107                         dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr;
 108
 109                         rdsdebug("local ipaddr = %x port %d, "
 110                                  "remote ipaddr = %x port %d"
 111                                  "..looking for %x port %d, "
 112                                  "remote ipaddr = %x port %d\n",
 113                                 src_addr->sin_addr.s_addr,
 114                                 src_addr->sin_port,
 115                                 dst_addr->sin_addr.s_addr,
 116                                 dst_addr->sin_port,
 117                                 src->sin_addr.s_addr,
 118                                 src->sin_port,
 119                                 dst->sin_addr.s_addr,
 120                                 dst->sin_port);
 121 #ifdef WORKING_TUPLE_DETECTION
 122                         if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr &&
 123                             src_addr->sin_port == src->sin_port &&
 124                             dst_addr->sin_addr.s_addr == dst->sin_addr.s_addr &&
 125                             dst_addr->sin_port == dst->sin_port) {
 126 #else
 127                         /* FIXME - needs to compare the local and remote
 128                          * ipaddr/port tuple, but the ipaddr is the only
 129                          * available information in the rds_sock (as the rest are
 130                          * zero'ed.  It doesn't appear to be properly populated
 131                          * during connection setup...
 132                          */
 133                         if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr) {
 134 #endif
 135                                 spin_unlock_irq(&iwdev->spinlock);
 136                                 *rds_iwdev = iwdev;
 137                                 *cm_id = i_cm_id->cm_id;
 138                                 return 0;
 139                         }
 140                 }
 141                 spin_unlock_irq(&iwdev->spinlock);
 142         }
 143
 144         return 1;
 145 }
 146
 147 static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
 148 {
 149         struct rds_iw_cm_id *i_cm_id;
 150
 151         i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL);
 152         if (!i_cm_id)
 153                 return -ENOMEM;
 154
 155         i_cm_id->cm_id = cm_id;
 156
 157         spin_lock_irq(&rds_iwdev->spinlock);
 158         list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list);
 159         spin_unlock_irq(&rds_iwdev->spinlock);
 160
 161         return 0;
 162 }
 163
 164 static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev,
 165                                 struct rdma_cm_id *cm_id)
 166 {
 167         struct rds_iw_cm_id *i_cm_id;
 168
 169         spin_lock_irq(&rds_iwdev->spinlock);
 170         list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) {
 171                 if (i_cm_id->cm_id == cm_id) {
 172                         list_del(&i_cm_id->list);
 173                         kfree(i_cm_id);
 174                         break;
 175                 }
 176         }
 177         spin_unlock_irq(&rds_iwdev->spinlock);
 178 }
 179
 180
 181 int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
 182 {
 183         struct sockaddr_in *src_addr, *dst_addr;
 184         struct rds_iw_device *rds_iwdev_old;
 185         struct rdma_cm_id *pcm_id;
 186         int rc;
 187
 188         src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr;
 189         dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr;
 190
 191         rc = rds_iw_get_device(src_addr, dst_addr, &rds_iwdev_old, &pcm_id);
 192         if (rc)
 193                 rds_iw_remove_cm_id(rds_iwdev, cm_id);
 194
 195         return rds_iw_add_cm_id(rds_iwdev, cm_id);
 196 }
 197
 198 void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
 199 {
 200         struct rds_iw_connection *ic = conn->c_transport_data;
 201
 202         /* conn was previously on the nodev_conns_list */
 203         spin_lock_irq(&iw_nodev_conns_lock);
 204         BUG_ON(list_empty(&iw_nodev_conns));
 205         BUG_ON(list_empty(&ic->iw_node));
 206         list_del(&ic->iw_node);
 207
 208         spin_lock(&rds_iwdev->spinlock);
 209         list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
 210         spin_unlock(&rds_iwdev->spinlock);
 211         spin_unlock_irq(&iw_nodev_conns_lock);
 212
 213         ic->rds_iwdev = rds_iwdev;
 214 }
 215
 216 void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
 217 {
 218         struct rds_iw_connection *ic = conn->c_transport_data;
 219
 220         /* place conn on nodev_conns_list */
 221         spin_lock(&iw_nodev_conns_lock);
 222
 223         spin_lock_irq(&rds_iwdev->spinlock);
 224         BUG_ON(list_empty(&ic->iw_node));
 225         list_del(&ic->iw_node);
 226         spin_unlock_irq(&rds_iwdev->spinlock);
 227
 228         list_add_tail(&ic->iw_node, &iw_nodev_conns);
 229
 230         spin_unlock(&iw_nodev_conns_lock);
 231
 232         rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
 233         ic->rds_iwdev = NULL;
 234 }
 235
 236 void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
 237 {
 238         struct rds_iw_connection *ic, *_ic;
 239         LIST_HEAD(tmp_list);
 240
 241         /* avoid calling conn_destroy with irqs off */
 242         spin_lock_irq(list_lock);
 243         list_splice(list, &tmp_list);
 244         INIT_LIST_HEAD(list);
 245         spin_unlock_irq(list_lock);
 246
 247         list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node)
 248                 rds_conn_destroy(ic->conn);
 249 }
 250
 251 static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg,
 252                 struct scatterlist *list, unsigned int sg_len)
 253 {
 254         sg->list = list;
 255         sg->len = sg_len;
 256         sg->dma_len = 0;
 257         sg->dma_npages = 0;
 258         sg->bytes = 0;
 259 }
 260
 261 static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev,
 262                         struct rds_iw_scatterlist *sg)
 263 {
 264         struct ib_device *dev = rds_iwdev->dev;
 265         u64 *dma_pages = NULL;
 266         int i, j, ret;
 267
 268         WARN_ON(sg->dma_len);
 269
 270         sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
 271         if (unlikely(!sg->dma_len)) {
 272                 printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n");
 273                 return ERR_PTR(-EBUSY);
 274         }
 275
 276         sg->bytes = 0;
 277         sg->dma_npages = 0;
 278
 279         ret = -EINVAL;
 280         for (i = 0; i < sg->dma_len; ++i) {
 281                 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
 282                 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
 283                 u64 end_addr;
 284
 285                 sg->bytes += dma_len;
 286
 287                 end_addr = dma_addr + dma_len;
 288                 if (dma_addr & PAGE_MASK) {
 289                         if (i > 0)
 290                                 goto out_unmap;
 291                         dma_addr &= ~PAGE_MASK;
 292                 }
 293                 if (end_addr & PAGE_MASK) {
 294                         if (i < sg->dma_len - 1)
 295                                 goto out_unmap;
 296                         end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK;
 297                 }
 298
 299                 sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT;
 300         }
 301
 302         /* Now gather the dma addrs into one list */
 303         if (sg->dma_npages > fastreg_message_size)
 304                 goto out_unmap;
 305
 306         dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC);
 307         if (!dma_pages) {
 308                 ret = -ENOMEM;
 309                 goto out_unmap;
 310         }
 311
 312         for (i = j = 0; i < sg->dma_len; ++i) {
 313                 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
 314                 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
 315                 u64 end_addr;
 316
 317                 end_addr = dma_addr + dma_len;
 318                 dma_addr &= ~PAGE_MASK;
 319                 for (; dma_addr < end_addr; dma_addr += PAGE_SIZE)
 320                         dma_pages[j++] = dma_addr;
 321                 BUG_ON(j > sg->dma_npages);
 322         }
 323
 324         return dma_pages;
 325
 326 out_unmap:
 327         ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
 328         sg->dma_len = 0;
 329         kfree(dma_pages);
 330         return ERR_PTR(ret);
 331 }
 332
 333
 334 struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev)
 335 {
 336         struct rds_iw_mr_pool *pool;
 337
 338         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
 339         if (!pool) {
 340                 printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n");
 341                 return ERR_PTR(-ENOMEM);
 342         }
 343
 344         pool->device = rds_iwdev;
 345         INIT_LIST_HEAD(&pool->dirty_list);
 346         INIT_LIST_HEAD(&pool->clean_list);
 347         mutex_init(&pool->flush_lock);
 348         spin_lock_init(&pool->list_lock);
 349         INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker);
 350
 351         pool->max_message_size = fastreg_message_size;
 352         pool->max_items = fastreg_pool_size;
 353         pool->max_free_pinned = pool->max_items * pool->max_message_size / 4;
 354         pool->max_pages = fastreg_message_size;
 355
 356         /* We never allow more than max_items MRs to be allocated.
 357          * When we exceed more than max_items_soft, we start freeing
 358          * items more aggressively.
 359          * Make sure that max_items > max_items_soft > max_items / 2
 360          */
 361         pool->max_items_soft = pool->max_items * 3 / 4;
 362
 363         return pool;
 364 }
 365
 366 void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo)
 367 {
 368         struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 369
 370         iinfo->rdma_mr_max = pool->max_items;
 371         iinfo->rdma_mr_size = pool->max_pages;
 372 }
 373
 374 void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool)
 375 {
 376         flush_workqueue(rds_wq);
 377         rds_iw_flush_mr_pool(pool, 1);
 378         BUG_ON(atomic_read(&pool->item_count));
 379         BUG_ON(atomic_read(&pool->free_pinned));
 380         kfree(pool);
 381 }
 382
 383 static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool)
 384 {
 385         struct rds_iw_mr *ibmr = NULL;
 386         unsigned long flags;
 387
 388         spin_lock_irqsave(&pool->list_lock, flags);
 389         if (!list_empty(&pool->clean_list)) {
 390                 ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list);
 391                 list_del_init(&ibmr->mapping.m_list);
 392         }
 393         spin_unlock_irqrestore(&pool->list_lock, flags);
 394
 395         return ibmr;
 396 }
 397
 398 static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev)
 399 {
 400         struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 401         struct rds_iw_mr *ibmr = NULL;
 402         int err = 0, iter = 0;
 403
 404         while (1) {
 405                 ibmr = rds_iw_reuse_fmr(pool);
 406                 if (ibmr)
 407                         return ibmr;
 408
 409                 /* No clean MRs - now we have the choice of either
 410                  * allocating a fresh MR up to the limit imposed by the
 411                  * driver, or flush any dirty unused MRs.
 412                  * We try to avoid stalling in the send path if possible,
 413                  * so we allocate as long as we're allowed to.
 414                  *
 415                  * We're fussy with enforcing the FMR limit, though. If the driver
 416                  * tells us we can't use more than N fmrs, we shouldn't start
 417                  * arguing with it */
 418                 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
 419                         break;
 420
 421                 atomic_dec(&pool->item_count);
 422
 423                 if (++iter > 2) {
 424                         rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted);
 425                         return ERR_PTR(-EAGAIN);
 426                 }
 427
 428                 /* We do have some empty MRs. Flush them out. */
 429                 rds_iw_stats_inc(s_iw_rdma_mr_pool_wait);
 430                 rds_iw_flush_mr_pool(pool, 0);
 431         }
 432
 433         ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
 434         if (!ibmr) {
 435                 err = -ENOMEM;
 436                 goto out_no_cigar;
 437         }
 438
 439         spin_lock_init(&ibmr->mapping.m_lock);
 440         INIT_LIST_HEAD(&ibmr->mapping.m_list);
 441         ibmr->mapping.m_mr = ibmr;
 442
 443         err = rds_iw_init_fastreg(pool, ibmr);
 444         if (err)
 445                 goto out_no_cigar;
 446
 447         rds_iw_stats_inc(s_iw_rdma_mr_alloc);
 448         return ibmr;
 449
 450 out_no_cigar:
 451         if (ibmr) {
 452                 rds_iw_destroy_fastreg(pool, ibmr);
 453                 kfree(ibmr);
 454         }
 455         atomic_dec(&pool->item_count);
 456         return ERR_PTR(err);
 457 }
 458
 459 void rds_iw_sync_mr(void *trans_private, int direction)
 460 {
 461         struct rds_iw_mr *ibmr = trans_private;
 462         struct rds_iw_device *rds_iwdev = ibmr->device;
 463
 464         switch (direction) {
 465         case DMA_FROM_DEVICE:
 466                 ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list,
 467                         ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
 468                 break;
 469         case DMA_TO_DEVICE:
 470                 ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list,
 471                         ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
 472                 break;
 473         }
 474 }
 475
 476 /*
 477  * Flush our pool of MRs.
 478  * At a minimum, all currently unused MRs are unmapped.
 479  * If the number of MRs allocated exceeds the limit, we also try
 480  * to free as many MRs as needed to get back to this limit.
 481  */
 482 static void rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all)
 483 {
 484         struct rds_iw_mr *ibmr, *next;
 485         LIST_HEAD(unmap_list);
 486         LIST_HEAD(kill_list);
 487         unsigned long flags;
 488         unsigned int nfreed = 0, ncleaned = 0, unpinned = 0;
 489
 490         rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
 491
 492         mutex_lock(&pool->flush_lock);
 493
 494         spin_lock_irqsave(&pool->list_lock, flags);
 495         /* Get the list of all mappings to be destroyed */
 496         list_splice_init(&pool->dirty_list, &unmap_list);
 497         if (free_all)
 498                 list_splice_init(&pool->clean_list, &kill_list);
 499         spin_unlock_irqrestore(&pool->list_lock, flags);
 500
 501         /* Batched invalidate of dirty MRs.
 502          * For FMR based MRs, the mappings on the unmap list are
 503          * actually members of an ibmr (ibmr->mapping). They either
 504          * migrate to the kill_list, or have been cleaned and should be
 505          * moved to the clean_list.
 506          * For fastregs, they will be dynamically allocated, and
 507          * will be destroyed by the unmap function.
 508          */
 509         if (!list_empty(&unmap_list)) {
 510                 ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list,
 511                                                      &kill_list, &unpinned);
 512                 /* If we've been asked to destroy all MRs, move those
 513                  * that were simply cleaned to the kill list */
 514                 if (free_all)
 515                         list_splice_init(&unmap_list, &kill_list);
 516         }
 517
 518         /* Destroy any MRs that are past their best before date */
 519         list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) {
 520                 rds_iw_stats_inc(s_iw_rdma_mr_free);
 521                 list_del(&ibmr->mapping.m_list);
 522                 rds_iw_destroy_fastreg(pool, ibmr);
 523                 kfree(ibmr);
 524                 nfreed++;
 525         }
 526
 527         /* Anything that remains are laundered ibmrs, which we can add
 528          * back to the clean list. */
 529         if (!list_empty(&unmap_list)) {
 530                 spin_lock_irqsave(&pool->list_lock, flags);
 531                 list_splice(&unmap_list, &pool->clean_list);
 532                 spin_unlock_irqrestore(&pool->list_lock, flags);
 533         }
 534
 535         atomic_sub(unpinned, &pool->free_pinned);
 536         atomic_sub(ncleaned, &pool->dirty_count);
 537         atomic_sub(nfreed, &pool->item_count);
 538
 539         mutex_unlock(&pool->flush_lock);
 540 }
 541
 542 static void rds_iw_mr_pool_flush_worker(struct work_struct *work)
 543 {
 544         struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker);
 545
 546         rds_iw_flush_mr_pool(pool, 0);
 547 }
 548
 549 void rds_iw_free_mr(void *trans_private, int invalidate)
 550 {
 551         struct rds_iw_mr *ibmr = trans_private;
 552         struct rds_iw_mr_pool *pool = ibmr->device->mr_pool;
 553
 554         rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len);
 555         if (!pool)
 556                 return;
 557
 558         /* Return it to the pool's free list */
 559         rds_iw_free_fastreg(pool, ibmr);
 560
 561         /* If we've pinned too many pages, request a flush */
 562         if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
 563             atomic_read(&pool->dirty_count) >= pool->max_items / 10)
 564                 queue_work(rds_wq, &pool->flush_worker);
 565
 566         if (invalidate) {
 567                 if (likely(!in_interrupt())) {
 568                         rds_iw_flush_mr_pool(pool, 0);
 569                 } else {
 570                         /* We get here if the user created a MR marked
 571                          * as use_once and invalidate at the same time. */
 572                         queue_work(rds_wq, &pool->flush_worker);
 573                 }
 574         }
 575 }
 576
 577 void rds_iw_flush_mrs(void)
 578 {
 579         struct rds_iw_device *rds_iwdev;
 580
 581         list_for_each_entry(rds_iwdev, &rds_iw_devices, list) {
 582                 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 583
 584                 if (pool)
 585                         rds_iw_flush_mr_pool(pool, 0);
 586         }
 587 }
 588
 589 void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
 590                     struct rds_sock *rs, u32 *key_ret)
 591 {
 592         struct rds_iw_device *rds_iwdev;
 593         struct rds_iw_mr *ibmr = NULL;
 594         struct rdma_cm_id *cm_id;
 595         struct sockaddr_in src = {
 596                 .sin_addr.s_addr = rs->rs_bound_addr,
 597                 .sin_port = rs->rs_bound_port,
 598         };
 599         struct sockaddr_in dst = {
 600                 .sin_addr.s_addr = rs->rs_conn_addr,
 601                 .sin_port = rs->rs_conn_port,
 602         };
 603         int ret;
 604
 605         ret = rds_iw_get_device(&src, &dst, &rds_iwdev, &cm_id);
 606         if (ret || !cm_id) {
 607                 ret = -ENODEV;
 608                 goto out;
 609         }
 610
 611         if (!rds_iwdev->mr_pool) {
 612                 ret = -ENODEV;
 613                 goto out;
 614         }
 615
 616         ibmr = rds_iw_alloc_mr(rds_iwdev);
 617         if (IS_ERR(ibmr))
 618                 return ibmr;
 619
 620         ibmr->cm_id = cm_id;
 621         ibmr->device = rds_iwdev;
 622
 623         ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents);
 624         if (ret == 0)
 625                 *key_ret = ibmr->mr->rkey;
 626         else
 627                 printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret);
 628
 629 out:
 630         if (ret) {
 631                 if (ibmr)
 632                         rds_iw_free_mr(ibmr, 0);
 633                 ibmr = ERR_PTR(ret);
 634         }
 635         return ibmr;
 636 }
 637
 638 /*
 639  * iWARP fastreg handling
 640  *
 641  * The life cycle of a fastreg registration is a bit different from
 642  * FMRs.
 643  * The idea behind fastreg is to have one MR, to which we bind different
 644  * mappings over time. To avoid stalling on the expensive map and invalidate
 645  * operations, these operations are pipelined on the same send queue on
 646  * which we want to send the message containing the r_key.
 647  *
 648  * This creates a bit of a problem for us, as we do not have the destination
 649  * IP in GET_MR, so the connection must be setup prior to the GET_MR call for
 650  * RDMA to be correctly setup.  If a fastreg request is present, rds_iw_xmit
 651  * will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request
 652  * before queuing the SEND. When completions for these arrive, they are
 653  * dispatched to the MR has a bit set showing that RDMa can be performed.
 654  *
 655  * There is another interesting aspect that's related to invalidation.
 656  * The application can request that a mapping is invalidated in FREE_MR.
 657  * The expectation there is that this invalidation step includes ALL
 658  * PREVIOUSLY FREED MRs.
 659  */
 660 static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool,
 661                                 struct rds_iw_mr *ibmr)
 662 {
 663         struct rds_iw_device *rds_iwdev = pool->device;
 664         struct ib_fast_reg_page_list *page_list = NULL;
 665         struct ib_mr *mr;
 666         int err;
 667
 668         mr = ib_alloc_mr(rds_iwdev->pd, IB_MR_TYPE_MEM_REG,
 669                          pool->max_message_size);
 670         if (IS_ERR(mr)) {
 671                 err = PTR_ERR(mr);
 672
 673                 printk(KERN_WARNING "RDS/IW: ib_alloc_mr failed (err=%d)\n", err);
 674                 return err;
 675         }
 676
 677         /* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages
 678          * is not filled in.
 679          */
 680         page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size);
 681         if (IS_ERR(page_list)) {
 682                 err = PTR_ERR(page_list);
 683
 684                 printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err);
 685                 ib_dereg_mr(mr);
 686                 return err;
 687         }
 688
 689         ibmr->page_list = page_list;
 690         ibmr->mr = mr;
 691         return 0;
 692 }
 693
 694 static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping)
 695 {
 696         struct rds_iw_mr *ibmr = mapping->m_mr;
 697         struct ib_send_wr f_wr, *failed_wr;
 698         int ret;
 699
 700         /*
 701          * Perform a WR for the fast_reg_mr. Each individual page
 702          * in the sg list is added to the fast reg page list and placed
 703          * inside the fast_reg_mr WR.  The key used is a rolling 8bit
 704          * counter, which should guarantee uniqueness.
 705          */
 706         ib_update_fast_reg_key(ibmr->mr, ibmr->remap_count++);
 707         mapping->m_rkey = ibmr->mr->rkey;
 708
 709         memset(&f_wr, 0, sizeof(f_wr));
 710         f_wr.wr_id = RDS_IW_FAST_REG_WR_ID;
 711         f_wr.opcode = IB_WR_FAST_REG_MR;
 712         f_wr.wr.fast_reg.length = mapping->m_sg.bytes;
 713         f_wr.wr.fast_reg.rkey = mapping->m_rkey;
 714         f_wr.wr.fast_reg.page_list = ibmr->page_list;
 715         f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len;
 716         f_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
 717         f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE |
 718                                 IB_ACCESS_REMOTE_READ |
 719                                 IB_ACCESS_REMOTE_WRITE;
 720         f_wr.wr.fast_reg.iova_start = 0;
 721         f_wr.send_flags = IB_SEND_SIGNALED;
 722
 723         failed_wr = &f_wr;
 724         ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr);
 725         BUG_ON(failed_wr != &f_wr);
 726         if (ret)
 727                 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
 728                         __func__, __LINE__, ret);
 729         return ret;
 730 }
 731
 732 static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr)
 733 {
 734         struct ib_send_wr s_wr, *failed_wr;
 735         int ret = 0;
 736
 737         if (!ibmr->cm_id->qp || !ibmr->mr)
 738                 goto out;
 739
 740         memset(&s_wr, 0, sizeof(s_wr));
 741         s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID;
 742         s_wr.opcode = IB_WR_LOCAL_INV;
 743         s_wr.ex.invalidate_rkey = ibmr->mr->rkey;
 744         s_wr.send_flags = IB_SEND_SIGNALED;
 745
 746         failed_wr = &s_wr;
 747         ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr);
 748         if (ret) {
 749                 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
 750                         __func__, __LINE__, ret);
 751                 goto out;
 752         }
 753 out:
 754         return ret;
 755 }
 756
 757 static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
 758                         struct rds_iw_mr *ibmr,
 759                         struct scatterlist *sg,
 760                         unsigned int sg_len)
 761 {
 762         struct rds_iw_device *rds_iwdev = pool->device;
 763         struct rds_iw_mapping *mapping = &ibmr->mapping;
 764         u64 *dma_pages;
 765         int i, ret = 0;
 766
 767         rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len);
 768
 769         dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg);
 770         if (IS_ERR(dma_pages)) {
 771                 ret = PTR_ERR(dma_pages);
 772                 dma_pages = NULL;
 773                 goto out;
 774         }
 775
 776         if (mapping->m_sg.dma_len > pool->max_message_size) {
 777                 ret = -EMSGSIZE;
 778                 goto out;
 779         }
 780
 781         for (i = 0; i < mapping->m_sg.dma_npages; ++i)
 782                 ibmr->page_list->page_list[i] = dma_pages[i];
 783
 784         ret = rds_iw_rdma_build_fastreg(mapping);
 785         if (ret)
 786                 goto out;
 787
 788         rds_iw_stats_inc(s_iw_rdma_mr_used);
 789
 790 out:
 791         kfree(dma_pages);
 792
 793         return ret;
 794 }
 795
 796 /*
 797  * "Free" a fastreg MR.
 798  */
 799 static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool,
 800                 struct rds_iw_mr *ibmr)
 801 {
 802         unsigned long flags;
 803         int ret;
 804
 805         if (!ibmr->mapping.m_sg.dma_len)
 806                 return;
 807
 808         ret = rds_iw_rdma_fastreg_inv(ibmr);
 809         if (ret)
 810                 return;
 811
 812         /* Try to post the LOCAL_INV WR to the queue. */
 813         spin_lock_irqsave(&pool->list_lock, flags);
 814
 815         list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list);
 816         atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned);
 817         atomic_inc(&pool->dirty_count);
 818
 819         spin_unlock_irqrestore(&pool->list_lock, flags);
 820 }
 821
 822 static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
 823                                 struct list_head *unmap_list,
 824                                 struct list_head *kill_list,
 825                                 int *unpinned)
 826 {
 827         struct rds_iw_mapping *mapping, *next;
 828         unsigned int ncleaned = 0;
 829         LIST_HEAD(laundered);
 830
 831         /* Batched invalidation of fastreg MRs.
 832          * Why do we do it this way, even though we could pipeline unmap
 833          * and remap? The reason is the application semantics - when the
 834          * application requests an invalidation of MRs, it expects all
 835          * previously released R_Keys to become invalid.
 836          *
 837          * If we implement MR reuse naively, we risk memory corruption
 838          * (this has actually been observed). So the default behavior
 839          * requires that a MR goes through an explicit unmap operation before
 840          * we can reuse it again.
 841          *
 842          * We could probably improve on this a little, by allowing immediate
 843          * reuse of a MR on the same socket (eg you could add small
 844          * cache of unused MRs to strct rds_socket - GET_MR could grab one
 845          * of these without requiring an explicit invalidate).
 846          */
 847         while (!list_empty(unmap_list)) {
 848                 unsigned long flags;
 849
 850                 spin_lock_irqsave(&pool->list_lock, flags);
 851                 list_for_each_entry_safe(mapping, next, unmap_list, m_list) {
 852                         *unpinned += mapping->m_sg.len;
 853                         list_move(&mapping->m_list, &laundered);
 854                         ncleaned++;
 855                 }
 856                 spin_unlock_irqrestore(&pool->list_lock, flags);
 857         }
 858
 859         /* Move all laundered mappings back to the unmap list.
 860          * We do not kill any WRs right now - it doesn't seem the
 861          * fastreg API has a max_remap limit. */
 862         list_splice_init(&laundered, unmap_list);
 863
 864         return ncleaned;
 865 }
 866
 867 static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool,
 868                 struct rds_iw_mr *ibmr)
 869 {
 870         if (ibmr->page_list)
 871                 ib_free_fast_reg_page_list(ibmr->page_list);
 872         if (ibmr->mr)
 873                 ib_dereg_mr(ibmr->mr);
 874 }