LXR linux/net/rds/ib

   1/*
   2 * Copyright (c) 2016 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 "ib_mr.h"
  34
  35static inline void
  36rds_transition_frwr_state(struct rds_ib_mr *ibmr,
  37                          enum rds_ib_fr_state old_state,
  38                          enum rds_ib_fr_state new_state)
  39{
  40        if (cmpxchg(&ibmr->u.frmr.fr_state,
  41                    old_state, new_state) == old_state &&
  42            old_state == FRMR_IS_INUSE) {
  43                /* enforce order of ibmr->u.frmr.fr_state update
  44                 * before decrementing i_fastreg_inuse_count
  45                 */
  46                smp_mb__before_atomic();
  47                atomic_dec(&ibmr->ic->i_fastreg_inuse_count);
  48                if (waitqueue_active(&rds_ib_ring_empty_wait))
  49                        wake_up(&rds_ib_ring_empty_wait);
  50        }
  51}
  52
  53static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
  54                                           int npages)
  55{
  56        struct rds_ib_mr_pool *pool;
  57        struct rds_ib_mr *ibmr = NULL;
  58        struct rds_ib_frmr *frmr;
  59        int err = 0;
  60
  61        if (npages <= RDS_MR_8K_MSG_SIZE)
  62                pool = rds_ibdev->mr_8k_pool;
  63        else
  64                pool = rds_ibdev->mr_1m_pool;
  65
  66        ibmr = rds_ib_try_reuse_ibmr(pool);
  67        if (ibmr)
  68                return ibmr;
  69
  70        ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
  71                            rdsibdev_to_node(rds_ibdev));
  72        if (!ibmr) {
  73                err = -ENOMEM;
  74                goto out_no_cigar;
  75        }
  76
  77        frmr = &ibmr->u.frmr;
  78        frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
  79                         pool->max_pages);
  80        if (IS_ERR(frmr->mr)) {
  81                pr_warn("RDS/IB: %s failed to allocate MR", __func__);
  82                err = PTR_ERR(frmr->mr);
  83                goto out_no_cigar;
  84        }
  85
  86        ibmr->pool = pool;
  87        if (pool->pool_type == RDS_IB_MR_8K_POOL)
  88                rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
  89        else
  90                rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
  91
  92        if (atomic_read(&pool->item_count) > pool->max_items_soft)
  93                pool->max_items_soft = pool->max_items;
  94
  95        frmr->fr_state = FRMR_IS_FREE;
  96        init_waitqueue_head(&frmr->fr_inv_done);
  97        init_waitqueue_head(&frmr->fr_reg_done);
  98        return ibmr;
  99
 100out_no_cigar:
 101        kfree(ibmr);
 102        atomic_dec(&pool->item_count);
 103        return ERR_PTR(err);
 104}
 105
 106static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop)
 107{
 108        struct rds_ib_mr_pool *pool = ibmr->pool;
 109
 110        if (drop)
 111                llist_add(&ibmr->llnode, &pool->drop_list);
 112        else
 113                llist_add(&ibmr->llnode, &pool->free_list);
 114        atomic_add(ibmr->sg_len, &pool->free_pinned);
 115        atomic_inc(&pool->dirty_count);
 116
 117        /* If we've pinned too many pages, request a flush */
 118        if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
 119            atomic_read(&pool->dirty_count) >= pool->max_items / 5)
 120                queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
 121}
 122
 123static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
 124{
 125        struct rds_ib_frmr *frmr = &ibmr->u.frmr;
 126        struct ib_reg_wr reg_wr;
 127        int ret, off = 0;
 128
 129        while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
 130                atomic_inc(&ibmr->ic->i_fastreg_wrs);
 131                cpu_relax();
 132        }
 133
 134        ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
 135                                &off, PAGE_SIZE);
 136        if (unlikely(ret != ibmr->sg_dma_len))
 137                return ret < 0 ? ret : -EINVAL;
 138
 139        if (cmpxchg(&frmr->fr_state,
 140                    FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE)
 141                return -EBUSY;
 142
 143        atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
 144
 145        /* Perform a WR for the fast_reg_mr. Each individual page
 146         * in the sg list is added to the fast reg page list and placed
 147         * inside the fast_reg_mr WR.  The key used is a rolling 8bit
 148         * counter, which should guarantee uniqueness.
 149         */
 150        ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
 151        frmr->fr_reg = true;
 152
 153        memset(&reg_wr, 0, sizeof(reg_wr));
 154        reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
 155        reg_wr.wr.opcode = IB_WR_REG_MR;
 156        reg_wr.wr.num_sge = 0;
 157        reg_wr.mr = frmr->mr;
 158        reg_wr.key = frmr->mr->rkey;
 159        reg_wr.access = IB_ACCESS_LOCAL_WRITE |
 160                        IB_ACCESS_REMOTE_READ |
 161                        IB_ACCESS_REMOTE_WRITE;
 162        reg_wr.wr.send_flags = IB_SEND_SIGNALED;
 163
 164        ret = ib_post_send(ibmr->ic->i_cm_id->qp, &reg_wr.wr, NULL);
 165        if (unlikely(ret)) {
 166                /* Failure here can be because of -ENOMEM as well */
 167                rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
 168
 169                atomic_inc(&ibmr->ic->i_fastreg_wrs);
 170                if (printk_ratelimit())
 171                        pr_warn("RDS/IB: %s returned error(%d)\n",
 172                                __func__, ret);
 173                goto out;
 174        }
 175
 176        /* Wait for the registration to complete in order to prevent an invalid
 177         * access error resulting from a race between the memory region already
 178         * being accessed while registration is still pending.
 179         */
 180        wait_event(frmr->fr_reg_done, !frmr->fr_reg);
 181
 182out:
 183
 184        return ret;
 185}
 186
 187static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
 188                           struct rds_ib_mr_pool *pool,
 189                           struct rds_ib_mr *ibmr,
 190                           struct scatterlist *sg, unsigned int sg_len)
 191{
 192        struct ib_device *dev = rds_ibdev->dev;
 193        struct rds_ib_frmr *frmr = &ibmr->u.frmr;
 194        int i;
 195        u32 len;
 196        int ret = 0;
 197
 198        /* We want to teardown old ibmr values here and fill it up with
 199         * new sg values
 200         */
 201        rds_ib_teardown_mr(ibmr);
 202
 203        ibmr->sg = sg;
 204        ibmr->sg_len = sg_len;
 205        ibmr->sg_dma_len = 0;
 206        frmr->sg_byte_len = 0;
 207        WARN_ON(ibmr->sg_dma_len);
 208        ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
 209                                         DMA_BIDIRECTIONAL);
 210        if (unlikely(!ibmr->sg_dma_len)) {
 211                pr_warn("RDS/IB: %s failed!\n", __func__);
 212                return -EBUSY;
 213        }
 214
 215        frmr->sg_byte_len = 0;
 216        frmr->dma_npages = 0;
 217        len = 0;
 218
 219        ret = -EINVAL;
 220        for (i = 0; i < ibmr->sg_dma_len; ++i) {
 221                unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
 222                u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
 223
 224                frmr->sg_byte_len += dma_len;
 225                if (dma_addr & ~PAGE_MASK) {
 226                        if (i > 0)
 227                                goto out_unmap;
 228                        else
 229                                ++frmr->dma_npages;
 230                }
 231
 232                if ((dma_addr + dma_len) & ~PAGE_MASK) {
 233                        if (i < ibmr->sg_dma_len - 1)
 234                                goto out_unmap;
 235                        else
 236                                ++frmr->dma_npages;
 237                }
 238
 239                len += dma_len;
 240        }
 241        frmr->dma_npages += len >> PAGE_SHIFT;
 242
 243        if (frmr->dma_npages > ibmr->pool->max_pages) {
 244                ret = -EMSGSIZE;
 245                goto out_unmap;
 246        }
 247
 248        ret = rds_ib_post_reg_frmr(ibmr);
 249        if (ret)
 250                goto out_unmap;
 251
 252        if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
 253                rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
 254        else
 255                rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
 256
 257        return ret;
 258
 259out_unmap:
 260        ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
 261                        DMA_BIDIRECTIONAL);
 262        ibmr->sg_dma_len = 0;
 263        return ret;
 264}
 265
 266static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
 267{
 268        struct ib_send_wr *s_wr;
 269        struct rds_ib_frmr *frmr = &ibmr->u.frmr;
 270        struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
 271        int ret = -EINVAL;
 272
 273        if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
 274                goto out;
 275
 276        if (frmr->fr_state != FRMR_IS_INUSE)
 277                goto out;
 278
 279        while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
 280                atomic_inc(&ibmr->ic->i_fastreg_wrs);
 281                cpu_relax();
 282        }
 283
 284        frmr->fr_inv = true;
 285        s_wr = &frmr->fr_wr;
 286
 287        memset(s_wr, 0, sizeof(*s_wr));
 288        s_wr->wr_id = (unsigned long)(void *)ibmr;
 289        s_wr->opcode = IB_WR_LOCAL_INV;
 290        s_wr->ex.invalidate_rkey = frmr->mr->rkey;
 291        s_wr->send_flags = IB_SEND_SIGNALED;
 292
 293        ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
 294        if (unlikely(ret)) {
 295                rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
 296                frmr->fr_inv = false;
 297                /* enforce order of frmr->fr_inv update
 298                 * before incrementing i_fastreg_wrs
 299                 */
 300                smp_mb__before_atomic();
 301                atomic_inc(&ibmr->ic->i_fastreg_wrs);
 302                pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
 303                goto out;
 304        }
 305
 306        /* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
 307         * 1) avoid a silly bouncing between "clean_list" and "drop_list"
 308         *    triggered by function "rds_ib_reg_frmr" as it is releases frmr
 309         *    regions whose state is not "FRMR_IS_FREE" right away.
 310         * 2) prevents an invalid access error in a race
 311         *    from a pending "IB_WR_LOCAL_INV" operation
 312         *    with a teardown ("dma_unmap_sg", "put_page")
 313         *    and de-registration ("ib_dereg_mr") of the corresponding
 314         *    memory region.
 315         */
 316        wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
 317
 318out:
 319        return ret;
 320}
 321
 322void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
 323{
 324        struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
 325        struct rds_ib_frmr *frmr = &ibmr->u.frmr;
 326
 327        if (wc->status != IB_WC_SUCCESS) {
 328                rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
 329                if (rds_conn_up(ic->conn))
 330                        rds_ib_conn_error(ic->conn,
 331                                          "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
 332                                          &ic->conn->c_laddr,
 333                                          &ic->conn->c_faddr,
 334                                          wc->status,
 335                                          ib_wc_status_msg(wc->status),
 336                                          wc->vendor_err);
 337        }
 338
 339        if (frmr->fr_inv) {
 340                rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
 341                frmr->fr_inv = false;
 342                wake_up(&frmr->fr_inv_done);
 343        }
 344
 345        if (frmr->fr_reg) {
 346                frmr->fr_reg = false;
 347                wake_up(&frmr->fr_reg_done);
 348        }
 349
 350        /* enforce order of frmr->{fr_reg,fr_inv} update
 351         * before incrementing i_fastreg_wrs
 352         */
 353        smp_mb__before_atomic();
 354        atomic_inc(&ic->i_fastreg_wrs);
 355}
 356
 357void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
 358                       unsigned long *unpinned, unsigned int goal)
 359{
 360        struct rds_ib_mr *ibmr, *next;
 361        struct rds_ib_frmr *frmr;
 362        int ret = 0, ret2;
 363        unsigned int freed = *nfreed;
 364
 365        /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
 366        list_for_each_entry(ibmr, list, unmap_list) {
 367                if (ibmr->sg_dma_len) {
 368                        ret2 = rds_ib_post_inv(ibmr);
 369                        if (ret2 && !ret)
 370                                ret = ret2;
 371                }
 372        }
 373
 374        if (ret)
 375                pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
 376
 377        /* Now we can destroy the DMA mapping and unpin any pages */
 378        list_for_each_entry_safe(ibmr, next, list, unmap_list) {
 379                *unpinned += ibmr->sg_len;
 380                frmr = &ibmr->u.frmr;
 381                __rds_ib_teardown_mr(ibmr);
 382                if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
 383                        /* Don't de-allocate if the MR is not free yet */
 384                        if (frmr->fr_state == FRMR_IS_INUSE)
 385                                continue;
 386
 387                        if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
 388                                rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
 389                        else
 390                                rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
 391                        list_del(&ibmr->unmap_list);
 392                        if (frmr->mr)
 393                                ib_dereg_mr(frmr->mr);
 394                        kfree(ibmr);
 395                        freed++;
 396                }
 397        }
 398        *nfreed = freed;
 399}
 400
 401struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
 402                                  struct rds_ib_connection *ic,
 403                                  struct scatterlist *sg,
 404                                  unsigned long nents, u32 *key)
 405{
 406        struct rds_ib_mr *ibmr = NULL;
 407        struct rds_ib_frmr *frmr;
 408        int ret;
 409
 410        if (!ic) {
 411                /* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
 412                return ERR_PTR(-EOPNOTSUPP);
 413        }
 414
 415        do {
 416                if (ibmr)
 417                        rds_ib_free_frmr(ibmr, true);
 418                ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
 419                if (IS_ERR(ibmr))
 420                        return ibmr;
 421                frmr = &ibmr->u.frmr;
 422        } while (frmr->fr_state != FRMR_IS_FREE);
 423
 424        ibmr->ic = ic;
 425        ibmr->device = rds_ibdev;
 426        ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
 427        if (ret == 0) {
 428                *key = frmr->mr->rkey;
 429        } else {
 430                rds_ib_free_frmr(ibmr, false);
 431                ibmr = ERR_PTR(ret);
 432        }
 433
 434        return ibmr;
 435}
 436
 437void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
 438{
 439        struct rds_ib_mr_pool *pool = ibmr->pool;
 440        struct rds_ib_frmr *frmr = &ibmr->u.frmr;
 441
 442        if (frmr->fr_state == FRMR_IS_STALE)
 443                llist_add(&ibmr->llnode, &pool->drop_list);
 444        else
 445                llist_add(&ibmr->llnode, &pool->free_list);
 446}
 447