net/rds/ib_frmr.c

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