linux/net/rds/iw_rdma.c
<<
>>
Prefs
   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 */
  44struct 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 */
  59struct 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
  78static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all);
  79static void rds_iw_mr_pool_flush_worker(struct work_struct *work);
  80static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  81static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
  82                          struct rds_iw_mr *ibmr,
  83                          struct scatterlist *sg, unsigned int nents);
  84static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  85static 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);
  89static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
  90
  91static int rds_iw_get_device(struct rds_sock *rs, struct rds_iw_device **rds_iwdev, struct rdma_cm_id **cm_id)
  92{
  93        struct rds_iw_device *iwdev;
  94        struct rds_iw_cm_id *i_cm_id;
  95
  96        *rds_iwdev = NULL;
  97        *cm_id = NULL;
  98
  99        list_for_each_entry(iwdev, &rds_iw_devices, list) {
 100                spin_lock_irq(&iwdev->spinlock);
 101                list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) {
 102                        struct sockaddr_in *src_addr, *dst_addr;
 103
 104                        src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr;
 105                        dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr;
 106
 107                        rdsdebug("local ipaddr = %x port %d, "
 108                                 "remote ipaddr = %x port %d"
 109                                 "..looking for %x port %d, "
 110                                 "remote ipaddr = %x port %d\n",
 111                                src_addr->sin_addr.s_addr,
 112                                src_addr->sin_port,
 113                                dst_addr->sin_addr.s_addr,
 114                                dst_addr->sin_port,
 115                                rs->rs_bound_addr,
 116                                rs->rs_bound_port,
 117                                rs->rs_conn_addr,
 118                                rs->rs_conn_port);
 119#ifdef WORKING_TUPLE_DETECTION
 120                        if (src_addr->sin_addr.s_addr == rs->rs_bound_addr &&
 121                            src_addr->sin_port == rs->rs_bound_port &&
 122                            dst_addr->sin_addr.s_addr == rs->rs_conn_addr &&
 123                            dst_addr->sin_port == rs->rs_conn_port) {
 124#else
 125                        /* FIXME - needs to compare the local and remote
 126                         * ipaddr/port tuple, but the ipaddr is the only
 127                         * available information in the rds_sock (as the rest are
 128                         * zero'ed.  It doesn't appear to be properly populated
 129                         * during connection setup...
 130                         */
 131                        if (src_addr->sin_addr.s_addr == rs->rs_bound_addr) {
 132#endif
 133                                spin_unlock_irq(&iwdev->spinlock);
 134                                *rds_iwdev = iwdev;
 135                                *cm_id = i_cm_id->cm_id;
 136                                return 0;
 137                        }
 138                }
 139                spin_unlock_irq(&iwdev->spinlock);
 140        }
 141
 142        return 1;
 143}
 144
 145static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
 146{
 147        struct rds_iw_cm_id *i_cm_id;
 148
 149        i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL);
 150        if (!i_cm_id)
 151                return -ENOMEM;
 152
 153        i_cm_id->cm_id = cm_id;
 154
 155        spin_lock_irq(&rds_iwdev->spinlock);
 156        list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list);
 157        spin_unlock_irq(&rds_iwdev->spinlock);
 158
 159        return 0;
 160}
 161
 162static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev,
 163                                struct rdma_cm_id *cm_id)
 164{
 165        struct rds_iw_cm_id *i_cm_id;
 166
 167        spin_lock_irq(&rds_iwdev->spinlock);
 168        list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) {
 169                if (i_cm_id->cm_id == cm_id) {
 170                        list_del(&i_cm_id->list);
 171                        kfree(i_cm_id);
 172                        break;
 173                }
 174        }
 175        spin_unlock_irq(&rds_iwdev->spinlock);
 176}
 177
 178
 179int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
 180{
 181        struct sockaddr_in *src_addr, *dst_addr;
 182        struct rds_iw_device *rds_iwdev_old;
 183        struct rds_sock rs;
 184        struct rdma_cm_id *pcm_id;
 185        int rc;
 186
 187        src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr;
 188        dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr;
 189
 190        rs.rs_bound_addr = src_addr->sin_addr.s_addr;
 191        rs.rs_bound_port = src_addr->sin_port;
 192        rs.rs_conn_addr = dst_addr->sin_addr.s_addr;
 193        rs.rs_conn_port = dst_addr->sin_port;
 194
 195        rc = rds_iw_get_device(&rs, &rds_iwdev_old, &pcm_id);
 196        if (rc)
 197                rds_iw_remove_cm_id(rds_iwdev, cm_id);
 198
 199        return rds_iw_add_cm_id(rds_iwdev, cm_id);
 200}
 201
 202void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
 203{
 204        struct rds_iw_connection *ic = conn->c_transport_data;
 205
 206        /* conn was previously on the nodev_conns_list */
 207        spin_lock_irq(&iw_nodev_conns_lock);
 208        BUG_ON(list_empty(&iw_nodev_conns));
 209        BUG_ON(list_empty(&ic->iw_node));
 210        list_del(&ic->iw_node);
 211
 212        spin_lock(&rds_iwdev->spinlock);
 213        list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
 214        spin_unlock(&rds_iwdev->spinlock);
 215        spin_unlock_irq(&iw_nodev_conns_lock);
 216
 217        ic->rds_iwdev = rds_iwdev;
 218}
 219
 220void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
 221{
 222        struct rds_iw_connection *ic = conn->c_transport_data;
 223
 224        /* place conn on nodev_conns_list */
 225        spin_lock(&iw_nodev_conns_lock);
 226
 227        spin_lock_irq(&rds_iwdev->spinlock);
 228        BUG_ON(list_empty(&ic->iw_node));
 229        list_del(&ic->iw_node);
 230        spin_unlock_irq(&rds_iwdev->spinlock);
 231
 232        list_add_tail(&ic->iw_node, &iw_nodev_conns);
 233
 234        spin_unlock(&iw_nodev_conns_lock);
 235
 236        rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
 237        ic->rds_iwdev = NULL;
 238}
 239
 240void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
 241{
 242        struct rds_iw_connection *ic, *_ic;
 243        LIST_HEAD(tmp_list);
 244
 245        /* avoid calling conn_destroy with irqs off */
 246        spin_lock_irq(list_lock);
 247        list_splice(list, &tmp_list);
 248        INIT_LIST_HEAD(list);
 249        spin_unlock_irq(list_lock);
 250
 251        list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node)
 252                rds_conn_destroy(ic->conn);
 253}
 254
 255static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg,
 256                struct scatterlist *list, unsigned int sg_len)
 257{
 258        sg->list = list;
 259        sg->len = sg_len;
 260        sg->dma_len = 0;
 261        sg->dma_npages = 0;
 262        sg->bytes = 0;
 263}
 264
 265static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev,
 266                        struct rds_iw_scatterlist *sg)
 267{
 268        struct ib_device *dev = rds_iwdev->dev;
 269        u64 *dma_pages = NULL;
 270        int i, j, ret;
 271
 272        WARN_ON(sg->dma_len);
 273
 274        sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
 275        if (unlikely(!sg->dma_len)) {
 276                printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n");
 277                return ERR_PTR(-EBUSY);
 278        }
 279
 280        sg->bytes = 0;
 281        sg->dma_npages = 0;
 282
 283        ret = -EINVAL;
 284        for (i = 0; i < sg->dma_len; ++i) {
 285                unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
 286                u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
 287                u64 end_addr;
 288
 289                sg->bytes += dma_len;
 290
 291                end_addr = dma_addr + dma_len;
 292                if (dma_addr & PAGE_MASK) {
 293                        if (i > 0)
 294                                goto out_unmap;
 295                        dma_addr &= ~PAGE_MASK;
 296                }
 297                if (end_addr & PAGE_MASK) {
 298                        if (i < sg->dma_len - 1)
 299                                goto out_unmap;
 300                        end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK;
 301                }
 302
 303                sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT;
 304        }
 305
 306        /* Now gather the dma addrs into one list */
 307        if (sg->dma_npages > fastreg_message_size)
 308                goto out_unmap;
 309
 310        dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC);
 311        if (!dma_pages) {
 312                ret = -ENOMEM;
 313                goto out_unmap;
 314        }
 315
 316        for (i = j = 0; i < sg->dma_len; ++i) {
 317                unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
 318                u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
 319                u64 end_addr;
 320
 321                end_addr = dma_addr + dma_len;
 322                dma_addr &= ~PAGE_MASK;
 323                for (; dma_addr < end_addr; dma_addr += PAGE_SIZE)
 324                        dma_pages[j++] = dma_addr;
 325                BUG_ON(j > sg->dma_npages);
 326        }
 327
 328        return dma_pages;
 329
 330out_unmap:
 331        ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
 332        sg->dma_len = 0;
 333        kfree(dma_pages);
 334        return ERR_PTR(ret);
 335}
 336
 337
 338struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev)
 339{
 340        struct rds_iw_mr_pool *pool;
 341
 342        pool = kzalloc(sizeof(*pool), GFP_KERNEL);
 343        if (!pool) {
 344                printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n");
 345                return ERR_PTR(-ENOMEM);
 346        }
 347
 348        pool->device = rds_iwdev;
 349        INIT_LIST_HEAD(&pool->dirty_list);
 350        INIT_LIST_HEAD(&pool->clean_list);
 351        mutex_init(&pool->flush_lock);
 352        spin_lock_init(&pool->list_lock);
 353        INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker);
 354
 355        pool->max_message_size = fastreg_message_size;
 356        pool->max_items = fastreg_pool_size;
 357        pool->max_free_pinned = pool->max_items * pool->max_message_size / 4;
 358        pool->max_pages = fastreg_message_size;
 359
 360        /* We never allow more than max_items MRs to be allocated.
 361         * When we exceed more than max_items_soft, we start freeing
 362         * items more aggressively.
 363         * Make sure that max_items > max_items_soft > max_items / 2
 364         */
 365        pool->max_items_soft = pool->max_items * 3 / 4;
 366
 367        return pool;
 368}
 369
 370void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo)
 371{
 372        struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 373
 374        iinfo->rdma_mr_max = pool->max_items;
 375        iinfo->rdma_mr_size = pool->max_pages;
 376}
 377
 378void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool)
 379{
 380        flush_workqueue(rds_wq);
 381        rds_iw_flush_mr_pool(pool, 1);
 382        BUG_ON(atomic_read(&pool->item_count));
 383        BUG_ON(atomic_read(&pool->free_pinned));
 384        kfree(pool);
 385}
 386
 387static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool)
 388{
 389        struct rds_iw_mr *ibmr = NULL;
 390        unsigned long flags;
 391
 392        spin_lock_irqsave(&pool->list_lock, flags);
 393        if (!list_empty(&pool->clean_list)) {
 394                ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list);
 395                list_del_init(&ibmr->mapping.m_list);
 396        }
 397        spin_unlock_irqrestore(&pool->list_lock, flags);
 398
 399        return ibmr;
 400}
 401
 402static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev)
 403{
 404        struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 405        struct rds_iw_mr *ibmr = NULL;
 406        int err = 0, iter = 0;
 407
 408        while (1) {
 409                ibmr = rds_iw_reuse_fmr(pool);
 410                if (ibmr)
 411                        return ibmr;
 412
 413                /* No clean MRs - now we have the choice of either
 414                 * allocating a fresh MR up to the limit imposed by the
 415                 * driver, or flush any dirty unused MRs.
 416                 * We try to avoid stalling in the send path if possible,
 417                 * so we allocate as long as we're allowed to.
 418                 *
 419                 * We're fussy with enforcing the FMR limit, though. If the driver
 420                 * tells us we can't use more than N fmrs, we shouldn't start
 421                 * arguing with it */
 422                if (atomic_inc_return(&pool->item_count) <= pool->max_items)
 423                        break;
 424
 425                atomic_dec(&pool->item_count);
 426
 427                if (++iter > 2) {
 428                        rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted);
 429                        return ERR_PTR(-EAGAIN);
 430                }
 431
 432                /* We do have some empty MRs. Flush them out. */
 433                rds_iw_stats_inc(s_iw_rdma_mr_pool_wait);
 434                rds_iw_flush_mr_pool(pool, 0);
 435        }
 436
 437        ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
 438        if (!ibmr) {
 439                err = -ENOMEM;
 440                goto out_no_cigar;
 441        }
 442
 443        spin_lock_init(&ibmr->mapping.m_lock);
 444        INIT_LIST_HEAD(&ibmr->mapping.m_list);
 445        ibmr->mapping.m_mr = ibmr;
 446
 447        err = rds_iw_init_fastreg(pool, ibmr);
 448        if (err)
 449                goto out_no_cigar;
 450
 451        rds_iw_stats_inc(s_iw_rdma_mr_alloc);
 452        return ibmr;
 453
 454out_no_cigar:
 455        if (ibmr) {
 456                rds_iw_destroy_fastreg(pool, ibmr);
 457                kfree(ibmr);
 458        }
 459        atomic_dec(&pool->item_count);
 460        return ERR_PTR(err);
 461}
 462
 463void rds_iw_sync_mr(void *trans_private, int direction)
 464{
 465        struct rds_iw_mr *ibmr = trans_private;
 466        struct rds_iw_device *rds_iwdev = ibmr->device;
 467
 468        switch (direction) {
 469        case DMA_FROM_DEVICE:
 470                ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list,
 471                        ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
 472                break;
 473        case DMA_TO_DEVICE:
 474                ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list,
 475                        ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
 476                break;
 477        }
 478}
 479
 480/*
 481 * Flush our pool of MRs.
 482 * At a minimum, all currently unused MRs are unmapped.
 483 * If the number of MRs allocated exceeds the limit, we also try
 484 * to free as many MRs as needed to get back to this limit.
 485 */
 486static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all)
 487{
 488        struct rds_iw_mr *ibmr, *next;
 489        LIST_HEAD(unmap_list);
 490        LIST_HEAD(kill_list);
 491        unsigned long flags;
 492        unsigned int nfreed = 0, ncleaned = 0, unpinned = 0;
 493        int ret = 0;
 494
 495        rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
 496
 497        mutex_lock(&pool->flush_lock);
 498
 499        spin_lock_irqsave(&pool->list_lock, flags);
 500        /* Get the list of all mappings to be destroyed */
 501        list_splice_init(&pool->dirty_list, &unmap_list);
 502        if (free_all)
 503                list_splice_init(&pool->clean_list, &kill_list);
 504        spin_unlock_irqrestore(&pool->list_lock, flags);
 505
 506        /* Batched invalidate of dirty MRs.
 507         * For FMR based MRs, the mappings on the unmap list are
 508         * actually members of an ibmr (ibmr->mapping). They either
 509         * migrate to the kill_list, or have been cleaned and should be
 510         * moved to the clean_list.
 511         * For fastregs, they will be dynamically allocated, and
 512         * will be destroyed by the unmap function.
 513         */
 514        if (!list_empty(&unmap_list)) {
 515                ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list,
 516                                                     &kill_list, &unpinned);
 517                /* If we've been asked to destroy all MRs, move those
 518                 * that were simply cleaned to the kill list */
 519                if (free_all)
 520                        list_splice_init(&unmap_list, &kill_list);
 521        }
 522
 523        /* Destroy any MRs that are past their best before date */
 524        list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) {
 525                rds_iw_stats_inc(s_iw_rdma_mr_free);
 526                list_del(&ibmr->mapping.m_list);
 527                rds_iw_destroy_fastreg(pool, ibmr);
 528                kfree(ibmr);
 529                nfreed++;
 530        }
 531
 532        /* Anything that remains are laundered ibmrs, which we can add
 533         * back to the clean list. */
 534        if (!list_empty(&unmap_list)) {
 535                spin_lock_irqsave(&pool->list_lock, flags);
 536                list_splice(&unmap_list, &pool->clean_list);
 537                spin_unlock_irqrestore(&pool->list_lock, flags);
 538        }
 539
 540        atomic_sub(unpinned, &pool->free_pinned);
 541        atomic_sub(ncleaned, &pool->dirty_count);
 542        atomic_sub(nfreed, &pool->item_count);
 543
 544        mutex_unlock(&pool->flush_lock);
 545        return ret;
 546}
 547
 548static void rds_iw_mr_pool_flush_worker(struct work_struct *work)
 549{
 550        struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker);
 551
 552        rds_iw_flush_mr_pool(pool, 0);
 553}
 554
 555void rds_iw_free_mr(void *trans_private, int invalidate)
 556{
 557        struct rds_iw_mr *ibmr = trans_private;
 558        struct rds_iw_mr_pool *pool = ibmr->device->mr_pool;
 559
 560        rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len);
 561        if (!pool)
 562                return;
 563
 564        /* Return it to the pool's free list */
 565        rds_iw_free_fastreg(pool, ibmr);
 566
 567        /* If we've pinned too many pages, request a flush */
 568        if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
 569            atomic_read(&pool->dirty_count) >= pool->max_items / 10)
 570                queue_work(rds_wq, &pool->flush_worker);
 571
 572        if (invalidate) {
 573                if (likely(!in_interrupt())) {
 574                        rds_iw_flush_mr_pool(pool, 0);
 575                } else {
 576                        /* We get here if the user created a MR marked
 577                         * as use_once and invalidate at the same time. */
 578                        queue_work(rds_wq, &pool->flush_worker);
 579                }
 580        }
 581}
 582
 583void rds_iw_flush_mrs(void)
 584{
 585        struct rds_iw_device *rds_iwdev;
 586
 587        list_for_each_entry(rds_iwdev, &rds_iw_devices, list) {
 588                struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
 589
 590                if (pool)
 591                        rds_iw_flush_mr_pool(pool, 0);
 592        }
 593}
 594
 595void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
 596                    struct rds_sock *rs, u32 *key_ret)
 597{
 598        struct rds_iw_device *rds_iwdev;
 599        struct rds_iw_mr *ibmr = NULL;
 600        struct rdma_cm_id *cm_id;
 601        int ret;
 602
 603        ret = rds_iw_get_device(rs, &rds_iwdev, &cm_id);
 604        if (ret || !cm_id) {
 605                ret = -ENODEV;
 606                goto out;
 607        }
 608
 609        if (!rds_iwdev->mr_pool) {
 610                ret = -ENODEV;
 611                goto out;
 612        }
 613
 614        ibmr = rds_iw_alloc_mr(rds_iwdev);
 615        if (IS_ERR(ibmr))
 616                return ibmr;
 617
 618        ibmr->cm_id = cm_id;
 619        ibmr->device = rds_iwdev;
 620
 621        ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents);
 622        if (ret == 0)
 623                *key_ret = ibmr->mr->rkey;
 624        else
 625                printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret);
 626
 627out:
 628        if (ret) {
 629                if (ibmr)
 630                        rds_iw_free_mr(ibmr, 0);
 631                ibmr = ERR_PTR(ret);
 632        }
 633        return ibmr;
 634}
 635
 636/*
 637 * iWARP fastreg handling
 638 *
 639 * The life cycle of a fastreg registration is a bit different from
 640 * FMRs.
 641 * The idea behind fastreg is to have one MR, to which we bind different
 642 * mappings over time. To avoid stalling on the expensive map and invalidate
 643 * operations, these operations are pipelined on the same send queue on
 644 * which we want to send the message containing the r_key.
 645 *
 646 * This creates a bit of a problem for us, as we do not have the destination
 647 * IP in GET_MR, so the connection must be setup prior to the GET_MR call for
 648 * RDMA to be correctly setup.  If a fastreg request is present, rds_iw_xmit
 649 * will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request
 650 * before queuing the SEND. When completions for these arrive, they are
 651 * dispatched to the MR has a bit set showing that RDMa can be performed.
 652 *
 653 * There is another interesting aspect that's related to invalidation.
 654 * The application can request that a mapping is invalidated in FREE_MR.
 655 * The expectation there is that this invalidation step includes ALL
 656 * PREVIOUSLY FREED MRs.
 657 */
 658static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool,
 659                                struct rds_iw_mr *ibmr)
 660{
 661        struct rds_iw_device *rds_iwdev = pool->device;
 662        struct ib_fast_reg_page_list *page_list = NULL;
 663        struct ib_mr *mr;
 664        int err;
 665
 666        mr = ib_alloc_fast_reg_mr(rds_iwdev->pd, pool->max_message_size);
 667        if (IS_ERR(mr)) {
 668                err = PTR_ERR(mr);
 669
 670                printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_mr failed (err=%d)\n", err);
 671                return err;
 672        }
 673
 674        /* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages
 675         * is not filled in.
 676         */
 677        page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size);
 678        if (IS_ERR(page_list)) {
 679                err = PTR_ERR(page_list);
 680
 681                printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err);
 682                ib_dereg_mr(mr);
 683                return err;
 684        }
 685
 686        ibmr->page_list = page_list;
 687        ibmr->mr = mr;
 688        return 0;
 689}
 690
 691static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping)
 692{
 693        struct rds_iw_mr *ibmr = mapping->m_mr;
 694        struct ib_send_wr f_wr, *failed_wr;
 695        int ret;
 696
 697        /*
 698         * Perform a WR for the fast_reg_mr. Each individual page
 699         * in the sg list is added to the fast reg page list and placed
 700         * inside the fast_reg_mr WR.  The key used is a rolling 8bit
 701         * counter, which should guarantee uniqueness.
 702         */
 703        ib_update_fast_reg_key(ibmr->mr, ibmr->remap_count++);
 704        mapping->m_rkey = ibmr->mr->rkey;
 705
 706        memset(&f_wr, 0, sizeof(f_wr));
 707        f_wr.wr_id = RDS_IW_FAST_REG_WR_ID;
 708        f_wr.opcode = IB_WR_FAST_REG_MR;
 709        f_wr.wr.fast_reg.length = mapping->m_sg.bytes;
 710        f_wr.wr.fast_reg.rkey = mapping->m_rkey;
 711        f_wr.wr.fast_reg.page_list = ibmr->page_list;
 712        f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len;
 713        f_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
 714        f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE |
 715                                IB_ACCESS_REMOTE_READ |
 716                                IB_ACCESS_REMOTE_WRITE;
 717        f_wr.wr.fast_reg.iova_start = 0;
 718        f_wr.send_flags = IB_SEND_SIGNALED;
 719
 720        failed_wr = &f_wr;
 721        ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr);
 722        BUG_ON(failed_wr != &f_wr);
 723        if (ret)
 724                printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
 725                        __func__, __LINE__, ret);
 726        return ret;
 727}
 728
 729static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr)
 730{
 731        struct ib_send_wr s_wr, *failed_wr;
 732        int ret = 0;
 733
 734        if (!ibmr->cm_id->qp || !ibmr->mr)
 735                goto out;
 736
 737        memset(&s_wr, 0, sizeof(s_wr));
 738        s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID;
 739        s_wr.opcode = IB_WR_LOCAL_INV;
 740        s_wr.ex.invalidate_rkey = ibmr->mr->rkey;
 741        s_wr.send_flags = IB_SEND_SIGNALED;
 742
 743        failed_wr = &s_wr;
 744        ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr);
 745        if (ret) {
 746                printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
 747                        __func__, __LINE__, ret);
 748                goto out;
 749        }
 750out:
 751        return ret;
 752}
 753
 754static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
 755                        struct rds_iw_mr *ibmr,
 756                        struct scatterlist *sg,
 757                        unsigned int sg_len)
 758{
 759        struct rds_iw_device *rds_iwdev = pool->device;
 760        struct rds_iw_mapping *mapping = &ibmr->mapping;
 761        u64 *dma_pages;
 762        int i, ret = 0;
 763
 764        rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len);
 765
 766        dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg);
 767        if (IS_ERR(dma_pages)) {
 768                ret = PTR_ERR(dma_pages);
 769                dma_pages = NULL;
 770                goto out;
 771        }
 772
 773        if (mapping->m_sg.dma_len > pool->max_message_size) {
 774                ret = -EMSGSIZE;
 775                goto out;
 776        }
 777
 778        for (i = 0; i < mapping->m_sg.dma_npages; ++i)
 779                ibmr->page_list->page_list[i] = dma_pages[i];
 780
 781        ret = rds_iw_rdma_build_fastreg(mapping);
 782        if (ret)
 783                goto out;
 784
 785        rds_iw_stats_inc(s_iw_rdma_mr_used);
 786
 787out:
 788        kfree(dma_pages);
 789
 790        return ret;
 791}
 792
 793/*
 794 * "Free" a fastreg MR.
 795 */
 796static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool,
 797                struct rds_iw_mr *ibmr)
 798{
 799        unsigned long flags;
 800        int ret;
 801
 802        if (!ibmr->mapping.m_sg.dma_len)
 803                return;
 804
 805        ret = rds_iw_rdma_fastreg_inv(ibmr);
 806        if (ret)
 807                return;
 808
 809        /* Try to post the LOCAL_INV WR to the queue. */
 810        spin_lock_irqsave(&pool->list_lock, flags);
 811
 812        list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list);
 813        atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned);
 814        atomic_inc(&pool->dirty_count);
 815
 816        spin_unlock_irqrestore(&pool->list_lock, flags);
 817}
 818
 819static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
 820                                struct list_head *unmap_list,
 821                                struct list_head *kill_list,
 822                                int *unpinned)
 823{
 824        struct rds_iw_mapping *mapping, *next;
 825        unsigned int ncleaned = 0;
 826        LIST_HEAD(laundered);
 827
 828        /* Batched invalidation of fastreg MRs.
 829         * Why do we do it this way, even though we could pipeline unmap
 830         * and remap? The reason is the application semantics - when the
 831         * application requests an invalidation of MRs, it expects all
 832         * previously released R_Keys to become invalid.
 833         *
 834         * If we implement MR reuse naively, we risk memory corruption
 835         * (this has actually been observed). So the default behavior
 836         * requires that a MR goes through an explicit unmap operation before
 837         * we can reuse it again.
 838         *
 839         * We could probably improve on this a little, by allowing immediate
 840         * reuse of a MR on the same socket (eg you could add small
 841         * cache of unused MRs to strct rds_socket - GET_MR could grab one
 842         * of these without requiring an explicit invalidate).
 843         */
 844        while (!list_empty(unmap_list)) {
 845                unsigned long flags;
 846
 847                spin_lock_irqsave(&pool->list_lock, flags);
 848                list_for_each_entry_safe(mapping, next, unmap_list, m_list) {
 849                        *unpinned += mapping->m_sg.len;
 850                        list_move(&mapping->m_list, &laundered);
 851                        ncleaned++;
 852                }
 853                spin_unlock_irqrestore(&pool->list_lock, flags);
 854        }
 855
 856        /* Move all laundered mappings back to the unmap list.
 857         * We do not kill any WRs right now - it doesn't seem the
 858         * fastreg API has a max_remap limit. */
 859        list_splice_init(&laundered, unmap_list);
 860
 861        return ncleaned;
 862}
 863
 864static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool,
 865                struct rds_iw_mr *ibmr)
 866{
 867        if (ibmr->page_list)
 868                ib_free_fast_reg_page_list(ibmr->page_list);
 869        if (ibmr->mr)
 870                ib_dereg_mr(ibmr->mr);
 871}
 872
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.