drivers/infiniband/ulp/iser/iser_memory.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/slab.h>
  36 #include <linux/mm.h>
  37 #include <linux/highmem.h>
  38 #include <linux/scatterlist.h>
  39
  40 #include "iscsi_iser.h"
  41
  42 void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
  43 {
  44         iser_err_comp(wc, "memreg");
  45 }
  46
  47 static struct iser_fr_desc *
  48 iser_reg_desc_get_fr(struct ib_conn *ib_conn)
  49 {
  50         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
  51         struct iser_fr_desc *desc;
  52         unsigned long flags;
  53
  54         spin_lock_irqsave(&fr_pool->lock, flags);
  55         desc = list_first_entry(&fr_pool->list,
  56                                 struct iser_fr_desc, list);
  57         list_del(&desc->list);
  58         spin_unlock_irqrestore(&fr_pool->lock, flags);
  59
  60         return desc;
  61 }
  62
  63 static void
  64 iser_reg_desc_put_fr(struct ib_conn *ib_conn,
  65                      struct iser_fr_desc *desc)
  66 {
  67         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
  68         unsigned long flags;
  69
  70         spin_lock_irqsave(&fr_pool->lock, flags);
  71         list_add(&desc->list, &fr_pool->list);
  72         spin_unlock_irqrestore(&fr_pool->lock, flags);
  73 }
  74
  75 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
  76                             struct iser_data_buf *data,
  77                             enum iser_data_dir iser_dir,
  78                             enum dma_data_direction dma_dir)
  79 {
  80         struct ib_device *dev;
  81
  82         iser_task->dir[iser_dir] = 1;
  83         dev = iser_task->iser_conn->ib_conn.device->ib_device;
  84
  85         data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
  86         if (unlikely(data->dma_nents == 0)) {
  87                 iser_err("dma_map_sg failed!!!\n");
  88                 return -EINVAL;
  89         }
  90         return 0;
  91 }
  92
  93 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
  94                               struct iser_data_buf *data,
  95                               enum dma_data_direction dir)
  96 {
  97         struct ib_device *dev;
  98
  99         dev = iser_task->iser_conn->ib_conn.device->ib_device;
 100         ib_dma_unmap_sg(dev, data->sg, data->size, dir);
 101 }
 102
 103 static int
 104 iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
 105              struct iser_mem_reg *reg)
 106 {
 107         struct scatterlist *sg = mem->sg;
 108
 109         reg->sge.lkey = device->pd->local_dma_lkey;
 110         /*
 111          * FIXME: rework the registration code path to differentiate
 112          * rkey/lkey use cases
 113          */
 114
 115         if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
 116                 reg->rkey = device->pd->unsafe_global_rkey;
 117         else
 118                 reg->rkey = 0;
 119         reg->sge.addr = sg_dma_address(&sg[0]);
 120         reg->sge.length = sg_dma_len(&sg[0]);
 121
 122         iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
 123                  " length=0x%x\n", reg->sge.lkey, reg->rkey,
 124                  reg->sge.addr, reg->sge.length);
 125
 126         return 0;
 127 }
 128
 129 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 130                             enum iser_data_dir cmd_dir)
 131 {
 132         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
 133         struct iser_fr_desc *desc;
 134         struct ib_mr_status mr_status;
 135
 136         desc = reg->mem_h;
 137         if (!desc)
 138                 return;
 139
 140         /*
 141          * The signature MR cannot be invalidated and reused without checking.
 142          * libiscsi calls the check_protection transport handler only if
 143          * SCSI-Response is received. And the signature MR is not checked if
 144          * the task is completed for some other reason like a timeout or error
 145          * handling. That's why we must check the signature MR here before
 146          * putting it to the free pool.
 147          */
 148         if (unlikely(desc->sig_protected)) {
 149                 desc->sig_protected = false;
 150                 ib_check_mr_status(desc->rsc.sig_mr, IB_MR_CHECK_SIG_STATUS,
 151                                    &mr_status);
 152         }
 153         iser_reg_desc_put_fr(&iser_task->iser_conn->ib_conn, reg->mem_h);
 154         reg->mem_h = NULL;
 155 }
 156
 157 static void
 158 iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_domain *domain)
 159 {
 160         domain->sig_type = IB_SIG_TYPE_T10_DIF;
 161         domain->sig.dif.pi_interval = scsi_prot_interval(sc);
 162         domain->sig.dif.ref_tag = t10_pi_ref_tag(sc->request);
 163         /*
 164          * At the moment we hard code those, but in the future
 165          * we will take them from sc.
 166          */
 167         domain->sig.dif.apptag_check_mask = 0xffff;
 168         domain->sig.dif.app_escape = true;
 169         domain->sig.dif.ref_escape = true;
 170         if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
 171                 domain->sig.dif.ref_remap = true;
 172 };
 173
 174 static int
 175 iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
 176 {
 177         switch (scsi_get_prot_op(sc)) {
 178         case SCSI_PROT_WRITE_INSERT:
 179         case SCSI_PROT_READ_STRIP:
 180                 sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
 181                 iser_set_dif_domain(sc, &sig_attrs->wire);
 182                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 183                 break;
 184         case SCSI_PROT_READ_INSERT:
 185         case SCSI_PROT_WRITE_STRIP:
 186                 sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
 187                 iser_set_dif_domain(sc, &sig_attrs->mem);
 188                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 189                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 190                 break;
 191         case SCSI_PROT_READ_PASS:
 192         case SCSI_PROT_WRITE_PASS:
 193                 iser_set_dif_domain(sc, &sig_attrs->wire);
 194                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 195                 iser_set_dif_domain(sc, &sig_attrs->mem);
 196                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 197                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 198                 break;
 199         default:
 200                 iser_err("Unsupported PI operation %d\n",
 201                          scsi_get_prot_op(sc));
 202                 return -EINVAL;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static inline void
 209 iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
 210 {
 211         *mask = 0;
 212         if (sc->prot_flags & SCSI_PROT_REF_CHECK)
 213                 *mask |= IB_SIG_CHECK_REFTAG;
 214         if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
 215                 *mask |= IB_SIG_CHECK_GUARD;
 216 }
 217
 218 static inline void
 219 iser_inv_rkey(struct ib_send_wr *inv_wr,
 220               struct ib_mr *mr,
 221               struct ib_cqe *cqe,
 222               struct ib_send_wr *next_wr)
 223 {
 224         inv_wr->opcode = IB_WR_LOCAL_INV;
 225         inv_wr->wr_cqe = cqe;
 226         inv_wr->ex.invalidate_rkey = mr->rkey;
 227         inv_wr->send_flags = 0;
 228         inv_wr->num_sge = 0;
 229         inv_wr->next = next_wr;
 230 }
 231
 232 static int
 233 iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
 234                 struct iser_data_buf *mem,
 235                 struct iser_data_buf *sig_mem,
 236                 struct iser_reg_resources *rsc,
 237                 struct iser_mem_reg *sig_reg)
 238 {
 239         struct iser_tx_desc *tx_desc = &iser_task->desc;
 240         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 241         struct ib_mr *mr = rsc->sig_mr;
 242         struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
 243         struct ib_reg_wr *wr = &tx_desc->reg_wr;
 244         int ret;
 245
 246         memset(sig_attrs, 0, sizeof(*sig_attrs));
 247         ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
 248         if (ret)
 249                 goto err;
 250
 251         iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
 252
 253         if (rsc->mr_valid)
 254                 iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
 255
 256         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 257
 258         ret = ib_map_mr_sg_pi(mr, mem->sg, mem->dma_nents, NULL,
 259                               sig_mem->sg, sig_mem->dma_nents, NULL, SZ_4K);
 260         if (unlikely(ret)) {
 261                 iser_err("failed to map PI sg (%d)\n",
 262                          mem->dma_nents + sig_mem->dma_nents);
 263                 goto err;
 264         }
 265
 266         memset(wr, 0, sizeof(*wr));
 267         wr->wr.next = &tx_desc->send_wr;
 268         wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
 269         wr->wr.wr_cqe = cqe;
 270         wr->wr.num_sge = 0;
 271         wr->wr.send_flags = 0;
 272         wr->mr = mr;
 273         wr->key = mr->rkey;
 274         wr->access = IB_ACCESS_LOCAL_WRITE |
 275                      IB_ACCESS_REMOTE_READ |
 276                      IB_ACCESS_REMOTE_WRITE;
 277         rsc->mr_valid = 1;
 278
 279         sig_reg->sge.lkey = mr->lkey;
 280         sig_reg->rkey = mr->rkey;
 281         sig_reg->sge.addr = mr->iova;
 282         sig_reg->sge.length = mr->length;
 283
 284         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
 285                  sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
 286                  sig_reg->sge.length);
 287 err:
 288         return ret;
 289 }
 290
 291 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
 292                             struct iser_data_buf *mem,
 293                             struct iser_reg_resources *rsc,
 294                             struct iser_mem_reg *reg)
 295 {
 296         struct iser_tx_desc *tx_desc = &iser_task->desc;
 297         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 298         struct ib_mr *mr = rsc->mr;
 299         struct ib_reg_wr *wr = &tx_desc->reg_wr;
 300         int n;
 301
 302         if (rsc->mr_valid)
 303                 iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
 304
 305         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 306
 307         n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SZ_4K);
 308         if (unlikely(n != mem->dma_nents)) {
 309                 iser_err("failed to map sg (%d/%d)\n",
 310                          n, mem->dma_nents);
 311                 return n < 0 ? n : -EINVAL;
 312         }
 313
 314         wr->wr.next = &tx_desc->send_wr;
 315         wr->wr.opcode = IB_WR_REG_MR;
 316         wr->wr.wr_cqe = cqe;
 317         wr->wr.send_flags = 0;
 318         wr->wr.num_sge = 0;
 319         wr->mr = mr;
 320         wr->key = mr->rkey;
 321         wr->access = IB_ACCESS_LOCAL_WRITE  |
 322                      IB_ACCESS_REMOTE_WRITE |
 323                      IB_ACCESS_REMOTE_READ;
 324
 325         rsc->mr_valid = 1;
 326
 327         reg->sge.lkey = mr->lkey;
 328         reg->rkey = mr->rkey;
 329         reg->sge.addr = mr->iova;
 330         reg->sge.length = mr->length;
 331
 332         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
 333                  reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
 334
 335         return 0;
 336 }
 337
 338 static int
 339 iser_reg_data_sg(struct iscsi_iser_task *task,
 340                  struct iser_data_buf *mem,
 341                  struct iser_fr_desc *desc,
 342                  bool use_dma_key,
 343                  struct iser_mem_reg *reg)
 344 {
 345         struct iser_device *device = task->iser_conn->ib_conn.device;
 346
 347         if (use_dma_key)
 348                 return iser_reg_dma(device, mem, reg);
 349
 350         return iser_fast_reg_mr(task, mem, &desc->rsc, reg);
 351 }
 352
 353 int iser_reg_mem_fastreg(struct iscsi_iser_task *task,
 354                          enum iser_data_dir dir,
 355                          bool all_imm)
 356 {
 357         struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
 358         struct iser_data_buf *mem = &task->data[dir];
 359         struct iser_mem_reg *reg = &task->rdma_reg[dir];
 360         struct iser_fr_desc *desc = NULL;
 361         bool use_dma_key;
 362         int err;
 363
 364         use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
 365                       scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
 366
 367         if (!use_dma_key) {
 368                 desc = iser_reg_desc_get_fr(ib_conn);
 369                 reg->mem_h = desc;
 370         }
 371
 372         if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL) {
 373                 err = iser_reg_data_sg(task, mem, desc, use_dma_key, reg);
 374                 if (unlikely(err))
 375                         goto err_reg;
 376         } else {
 377                 err = iser_reg_sig_mr(task, mem, &task->prot[dir],
 378                                       &desc->rsc, reg);
 379                 if (unlikely(err))
 380                         goto err_reg;
 381
 382                 desc->sig_protected = true;
 383         }
 384
 385         return 0;
 386
 387 err_reg:
 388         if (desc)
 389                 iser_reg_desc_put_fr(ib_conn, desc);
 390
 391         return err;
 392 }
 393