net/rds/ib_fmr.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 struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev, int npages)
  36 {
  37         struct rds_ib_mr_pool *pool;
  38         struct rds_ib_mr *ibmr = NULL;
  39         struct rds_ib_fmr *fmr;
  40         int err = 0;
  41
  42         if (npages <= RDS_MR_8K_MSG_SIZE)
  43                 pool = rds_ibdev->mr_8k_pool;
  44         else
  45                 pool = rds_ibdev->mr_1m_pool;
  46
  47         ibmr = rds_ib_try_reuse_ibmr(pool);
  48         if (ibmr)
  49                 return ibmr;
  50
  51         ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
  52                             rdsibdev_to_node(rds_ibdev));
  53         if (!ibmr) {
  54                 err = -ENOMEM;
  55                 goto out_no_cigar;
  56         }
  57
  58         fmr = &ibmr->u.fmr;
  59         fmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
  60                         (IB_ACCESS_LOCAL_WRITE |
  61                          IB_ACCESS_REMOTE_READ |
  62                          IB_ACCESS_REMOTE_WRITE |
  63                          IB_ACCESS_REMOTE_ATOMIC),
  64                         &pool->fmr_attr);
  65         if (IS_ERR(fmr->fmr)) {
  66                 err = PTR_ERR(fmr->fmr);
  67                 fmr->fmr = NULL;
  68                 pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, err);
  69                 goto out_no_cigar;
  70         }
  71
  72         ibmr->pool = pool;
  73         if (pool->pool_type == RDS_IB_MR_8K_POOL)
  74                 rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
  75         else
  76                 rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
  77
  78         return ibmr;
  79
  80 out_no_cigar:
  81         if (ibmr) {
  82                 if (fmr->fmr)
  83                         ib_dealloc_fmr(fmr->fmr);
  84                 kfree(ibmr);
  85         }
  86         atomic_dec(&pool->item_count);
  87         return ERR_PTR(err);
  88 }
  89
  90 int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
  91                    struct scatterlist *sg, unsigned int nents)
  92 {
  93         struct ib_device *dev = rds_ibdev->dev;
  94         struct rds_ib_fmr *fmr = &ibmr->u.fmr;
  95         struct scatterlist *scat = sg;
  96         u64 io_addr = 0;
  97         u64 *dma_pages;
  98         u32 len;
  99         int page_cnt, sg_dma_len;
 100         int i, j;
 101         int ret;
 102
 103         sg_dma_len = ib_dma_map_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
 104         if (unlikely(!sg_dma_len)) {
 105                 pr_warn("RDS/IB: %s failed!\n", __func__);
 106                 return -EBUSY;
 107         }
 108
 109         len = 0;
 110         page_cnt = 0;
 111
 112         for (i = 0; i < sg_dma_len; ++i) {
 113                 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
 114                 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
 115
 116                 if (dma_addr & ~PAGE_MASK) {
 117                         if (i > 0)
 118                                 return -EINVAL;
 119                         else
 120                                 ++page_cnt;
 121                 }
 122                 if ((dma_addr + dma_len) & ~PAGE_MASK) {
 123                         if (i < sg_dma_len - 1)
 124                                 return -EINVAL;
 125                         else
 126                                 ++page_cnt;
 127                 }
 128
 129                 len += dma_len;
 130         }
 131
 132         page_cnt += len >> PAGE_SHIFT;
 133         if (page_cnt > ibmr->pool->fmr_attr.max_pages)
 134                 return -EINVAL;
 135
 136         dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
 137                                  rdsibdev_to_node(rds_ibdev));
 138         if (!dma_pages)
 139                 return -ENOMEM;
 140
 141         page_cnt = 0;
 142         for (i = 0; i < sg_dma_len; ++i) {
 143                 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
 144                 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
 145
 146                 for (j = 0; j < dma_len; j += PAGE_SIZE)
 147                         dma_pages[page_cnt++] =
 148                                 (dma_addr & PAGE_MASK) + j;
 149         }
 150
 151         ret = ib_map_phys_fmr(fmr->fmr, dma_pages, page_cnt, io_addr);
 152         if (ret)
 153                 goto out;
 154
 155         /* Success - we successfully remapped the MR, so we can
 156          * safely tear down the old mapping.
 157          */
 158         rds_ib_teardown_mr(ibmr);
 159
 160         ibmr->sg = scat;
 161         ibmr->sg_len = nents;
 162         ibmr->sg_dma_len = sg_dma_len;
 163         ibmr->remap_count++;
 164
 165         if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
 166                 rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
 167         else
 168                 rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
 169         ret = 0;
 170
 171 out:
 172         kfree(dma_pages);
 173
 174         return ret;
 175 }
 176
 177 struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *rds_ibdev,
 178                                  struct scatterlist *sg,
 179                                  unsigned long nents,
 180                                  u32 *key)
 181 {
 182         struct rds_ib_mr *ibmr = NULL;
 183         struct rds_ib_fmr *fmr;
 184         int ret;
 185
 186         ibmr = rds_ib_alloc_fmr(rds_ibdev, nents);
 187         if (IS_ERR(ibmr))
 188                 return ibmr;
 189
 190         ibmr->device = rds_ibdev;
 191         fmr = &ibmr->u.fmr;
 192         ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
 193         if (ret == 0)
 194                 *key = fmr->fmr->rkey;
 195         else
 196                 rds_ib_free_mr(ibmr, 0);
 197
 198         return ibmr;
 199 }
 200
 201 void rds_ib_unreg_fmr(struct list_head *list, unsigned int *nfreed,
 202                       unsigned long *unpinned, unsigned int goal)
 203 {
 204         struct rds_ib_mr *ibmr, *next;
 205         struct rds_ib_fmr *fmr;
 206         LIST_HEAD(fmr_list);
 207         int ret = 0;
 208         unsigned int freed = *nfreed;
 209
 210         /* String all ib_mr's onto one list and hand them to  ib_unmap_fmr */
 211         list_for_each_entry(ibmr, list, unmap_list) {
 212                 fmr = &ibmr->u.fmr;
 213                 list_add(&fmr->fmr->list, &fmr_list);
 214         }
 215
 216         ret = ib_unmap_fmr(&fmr_list);
 217         if (ret)
 218                 pr_warn("RDS/IB: FMR invalidation failed (err=%d)\n", ret);
 219
 220         /* Now we can destroy the DMA mapping and unpin any pages */
 221         list_for_each_entry_safe(ibmr, next, list, unmap_list) {
 222                 fmr = &ibmr->u.fmr;
 223                 *unpinned += ibmr->sg_len;
 224                 __rds_ib_teardown_mr(ibmr);
 225                 if (freed < goal ||
 226                     ibmr->remap_count >= ibmr->pool->fmr_attr.max_maps) {
 227                         if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
 228                                 rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
 229                         else
 230                                 rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
 231                         list_del(&ibmr->unmap_list);
 232                         ib_dealloc_fmr(fmr->fmr);
 233                         kfree(ibmr);
 234                         freed++;
 235                 }
 236         }
 237         *nfreed = freed;
 238 }
 239
 240 void rds_ib_free_fmr_list(struct rds_ib_mr *ibmr)
 241 {
 242         struct rds_ib_mr_pool *pool = ibmr->pool;
 243
 244         if (ibmr->remap_count >= pool->fmr_attr.max_maps)
 245                 llist_add(&ibmr->llnode, &pool->drop_list);
 246         else
 247                 llist_add(&ibmr->llnode, &pool->free_list);
 248 }