drivers/infiniband/ulp/srpt/ib_srpt.c

   1 /*
   2  * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
   3  * Copyright (C) 2008 - 2011 Bart Van Assche <bvanassche@acm.org>.
   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  */
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/slab.h>
  38 #include <linux/err.h>
  39 #include <linux/ctype.h>
  40 #include <linux/kthread.h>
  41 #include <linux/string.h>
  42 #include <linux/delay.h>
  43 #include <linux/atomic.h>
  44 #include <scsi/scsi_tcq.h>
  45 #include <target/configfs_macros.h>
  46 #include <target/target_core_base.h>
  47 #include <target/target_core_fabric_configfs.h>
  48 #include <target/target_core_fabric.h>
  49 #include <target/target_core_configfs.h>
  50 #include "ib_srpt.h"
  51
  52 /* Name of this kernel module. */
  53 #define DRV_NAME                "ib_srpt"
  54 #define DRV_VERSION             "2.0.0"
  55 #define DRV_RELDATE             "2011-02-14"
  56
  57 #define SRPT_ID_STRING  "Linux SRP target"
  58
  59 #undef pr_fmt
  60 #define pr_fmt(fmt) DRV_NAME " " fmt
  61
  62 MODULE_AUTHOR("Vu Pham and Bart Van Assche");
  63 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol target "
  64                    "v" DRV_VERSION " (" DRV_RELDATE ")");
  65 MODULE_LICENSE("Dual BSD/GPL");
  66
  67 /*
  68  * Global Variables
  69  */
  70
  71 static u64 srpt_service_guid;
  72 static DEFINE_SPINLOCK(srpt_dev_lock);  /* Protects srpt_dev_list. */
  73 static LIST_HEAD(srpt_dev_list);        /* List of srpt_device structures. */
  74
  75 static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
  76 module_param(srp_max_req_size, int, 0444);
  77 MODULE_PARM_DESC(srp_max_req_size,
  78                  "Maximum size of SRP request messages in bytes.");
  79
  80 static int srpt_srq_size = DEFAULT_SRPT_SRQ_SIZE;
  81 module_param(srpt_srq_size, int, 0444);
  82 MODULE_PARM_DESC(srpt_srq_size,
  83                  "Shared receive queue (SRQ) size.");
  84
  85 static int srpt_get_u64_x(char *buffer, struct kernel_param *kp)
  86 {
  87         return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
  88 }
  89 module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
  90                   0444);
  91 MODULE_PARM_DESC(srpt_service_guid,
  92                  "Using this value for ioc_guid, id_ext, and cm_listen_id"
  93                  " instead of using the node_guid of the first HCA.");
  94
  95 static struct ib_client srpt_client;
  96 static struct target_fabric_configfs *srpt_target;
  97 static void srpt_release_channel(struct srpt_rdma_ch *ch);
  98 static int srpt_queue_status(struct se_cmd *cmd);
  99
 100 /**
 101  * opposite_dma_dir() - Swap DMA_TO_DEVICE and DMA_FROM_DEVICE.
 102  */
 103 static inline
 104 enum dma_data_direction opposite_dma_dir(enum dma_data_direction dir)
 105 {
 106         switch (dir) {
 107         case DMA_TO_DEVICE:     return DMA_FROM_DEVICE;
 108         case DMA_FROM_DEVICE:   return DMA_TO_DEVICE;
 109         default:                return dir;
 110         }
 111 }
 112
 113 /**
 114  * srpt_sdev_name() - Return the name associated with the HCA.
 115  *
 116  * Examples are ib0, ib1, ...
 117  */
 118 static inline const char *srpt_sdev_name(struct srpt_device *sdev)
 119 {
 120         return sdev->device->name;
 121 }
 122
 123 static enum rdma_ch_state srpt_get_ch_state(struct srpt_rdma_ch *ch)
 124 {
 125         unsigned long flags;
 126         enum rdma_ch_state state;
 127
 128         spin_lock_irqsave(&ch->spinlock, flags);
 129         state = ch->state;
 130         spin_unlock_irqrestore(&ch->spinlock, flags);
 131         return state;
 132 }
 133
 134 static enum rdma_ch_state
 135 srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new_state)
 136 {
 137         unsigned long flags;
 138         enum rdma_ch_state prev;
 139
 140         spin_lock_irqsave(&ch->spinlock, flags);
 141         prev = ch->state;
 142         ch->state = new_state;
 143         spin_unlock_irqrestore(&ch->spinlock, flags);
 144         return prev;
 145 }
 146
 147 /**
 148  * srpt_test_and_set_ch_state() - Test and set the channel state.
 149  *
 150  * Returns true if and only if the channel state has been set to the new state.
 151  */
 152 static bool
 153 srpt_test_and_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state old,
 154                            enum rdma_ch_state new)
 155 {
 156         unsigned long flags;
 157         enum rdma_ch_state prev;
 158
 159         spin_lock_irqsave(&ch->spinlock, flags);
 160         prev = ch->state;
 161         if (prev == old)
 162                 ch->state = new;
 163         spin_unlock_irqrestore(&ch->spinlock, flags);
 164         return prev == old;
 165 }
 166
 167 /**
 168  * srpt_event_handler() - Asynchronous IB event callback function.
 169  *
 170  * Callback function called by the InfiniBand core when an asynchronous IB
 171  * event occurs. This callback may occur in interrupt context. See also
 172  * section 11.5.2, Set Asynchronous Event Handler in the InfiniBand
 173  * Architecture Specification.
 174  */
 175 static void srpt_event_handler(struct ib_event_handler *handler,
 176                                struct ib_event *event)
 177 {
 178         struct srpt_device *sdev;
 179         struct srpt_port *sport;
 180
 181         sdev = ib_get_client_data(event->device, &srpt_client);
 182         if (!sdev || sdev->device != event->device)
 183                 return;
 184
 185         pr_debug("ASYNC event= %d on device= %s\n", event->event,
 186                  srpt_sdev_name(sdev));
 187
 188         switch (event->event) {
 189         case IB_EVENT_PORT_ERR:
 190                 if (event->element.port_num <= sdev->device->phys_port_cnt) {
 191                         sport = &sdev->port[event->element.port_num - 1];
 192                         sport->lid = 0;
 193                         sport->sm_lid = 0;
 194                 }
 195                 break;
 196         case IB_EVENT_PORT_ACTIVE:
 197         case IB_EVENT_LID_CHANGE:
 198         case IB_EVENT_PKEY_CHANGE:
 199         case IB_EVENT_SM_CHANGE:
 200         case IB_EVENT_CLIENT_REREGISTER:
 201                 /* Refresh port data asynchronously. */
 202                 if (event->element.port_num <= sdev->device->phys_port_cnt) {
 203                         sport = &sdev->port[event->element.port_num - 1];
 204                         if (!sport->lid && !sport->sm_lid)
 205                                 schedule_work(&sport->work);
 206                 }
 207                 break;
 208         default:
 209                 printk(KERN_ERR "received unrecognized IB event %d\n",
 210                        event->event);
 211                 break;
 212         }
 213 }
 214
 215 /**
 216  * srpt_srq_event() - SRQ event callback function.
 217  */
 218 static void srpt_srq_event(struct ib_event *event, void *ctx)
 219 {
 220         printk(KERN_INFO "SRQ event %d\n", event->event);
 221 }
 222
 223 /**
 224  * srpt_qp_event() - QP event callback function.
 225  */
 226 static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
 227 {
 228         pr_debug("QP event %d on cm_id=%p sess_name=%s state=%d\n",
 229                  event->event, ch->cm_id, ch->sess_name, srpt_get_ch_state(ch));
 230
 231         switch (event->event) {
 232         case IB_EVENT_COMM_EST:
 233                 ib_cm_notify(ch->cm_id, event->event);
 234                 break;
 235         case IB_EVENT_QP_LAST_WQE_REACHED:
 236                 if (srpt_test_and_set_ch_state(ch, CH_DRAINING,
 237                                                CH_RELEASING))
 238                         srpt_release_channel(ch);
 239                 else
 240                         pr_debug("%s: state %d - ignored LAST_WQE.\n",
 241                                  ch->sess_name, srpt_get_ch_state(ch));
 242                 break;
 243         default:
 244                 printk(KERN_ERR "received unrecognized IB QP event %d\n",
 245                        event->event);
 246                 break;
 247         }
 248 }
 249
 250 /**
 251  * srpt_set_ioc() - Helper function for initializing an IOUnitInfo structure.
 252  *
 253  * @slot: one-based slot number.
 254  * @value: four-bit value.
 255  *
 256  * Copies the lowest four bits of value in element slot of the array of four
 257  * bit elements called c_list (controller list). The index slot is one-based.
 258  */
 259 static void srpt_set_ioc(u8 *c_list, u32 slot, u8 value)
 260 {
 261         u16 id;
 262         u8 tmp;
 263
 264         id = (slot - 1) / 2;
 265         if (slot & 0x1) {
 266                 tmp = c_list[id] & 0xf;
 267                 c_list[id] = (value << 4) | tmp;
 268         } else {
 269                 tmp = c_list[id] & 0xf0;
 270                 c_list[id] = (value & 0xf) | tmp;
 271         }
 272 }
 273
 274 /**
 275  * srpt_get_class_port_info() - Copy ClassPortInfo to a management datagram.
 276  *
 277  * See also section 16.3.3.1 ClassPortInfo in the InfiniBand Architecture
 278  * Specification.
 279  */
 280 static void srpt_get_class_port_info(struct ib_dm_mad *mad)
 281 {
 282         struct ib_class_port_info *cif;
 283
 284         cif = (struct ib_class_port_info *)mad->data;
 285         memset(cif, 0, sizeof *cif);
 286         cif->base_version = 1;
 287         cif->class_version = 1;
 288         cif->resp_time_value = 20;
 289
 290         mad->mad_hdr.status = 0;
 291 }
 292
 293 /**
 294  * srpt_get_iou() - Write IOUnitInfo to a management datagram.
 295  *
 296  * See also section 16.3.3.3 IOUnitInfo in the InfiniBand Architecture
 297  * Specification. See also section B.7, table B.6 in the SRP r16a document.
 298  */
 299 static void srpt_get_iou(struct ib_dm_mad *mad)
 300 {
 301         struct ib_dm_iou_info *ioui;
 302         u8 slot;
 303         int i;
 304
 305         ioui = (struct ib_dm_iou_info *)mad->data;
 306         ioui->change_id = __constant_cpu_to_be16(1);
 307         ioui->max_controllers = 16;
 308
 309         /* set present for slot 1 and empty for the rest */
 310         srpt_set_ioc(ioui->controller_list, 1, 1);
 311         for (i = 1, slot = 2; i < 16; i++, slot++)
 312                 srpt_set_ioc(ioui->controller_list, slot, 0);
 313
 314         mad->mad_hdr.status = 0;
 315 }
 316
 317 /**
 318  * srpt_get_ioc() - Write IOControllerprofile to a management datagram.
 319  *
 320  * See also section 16.3.3.4 IOControllerProfile in the InfiniBand
 321  * Architecture Specification. See also section B.7, table B.7 in the SRP
 322  * r16a document.
 323  */
 324 static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
 325                          struct ib_dm_mad *mad)
 326 {
 327         struct srpt_device *sdev = sport->sdev;
 328         struct ib_dm_ioc_profile *iocp;
 329
 330         iocp = (struct ib_dm_ioc_profile *)mad->data;
 331
 332         if (!slot || slot > 16) {
 333                 mad->mad_hdr.status
 334                         = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
 335                 return;
 336         }
 337
 338         if (slot > 2) {
 339                 mad->mad_hdr.status
 340                         = __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
 341                 return;
 342         }
 343
 344         memset(iocp, 0, sizeof *iocp);
 345         strcpy(iocp->id_string, SRPT_ID_STRING);
 346         iocp->guid = cpu_to_be64(srpt_service_guid);
 347         iocp->vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
 348         iocp->device_id = cpu_to_be32(sdev->dev_attr.vendor_part_id);
 349         iocp->device_version = cpu_to_be16(sdev->dev_attr.hw_ver);
 350         iocp->subsys_vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
 351         iocp->subsys_device_id = 0x0;
 352         iocp->io_class = __constant_cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
 353         iocp->io_subclass = __constant_cpu_to_be16(SRP_IO_SUBCLASS);
 354         iocp->protocol = __constant_cpu_to_be16(SRP_PROTOCOL);
 355         iocp->protocol_version = __constant_cpu_to_be16(SRP_PROTOCOL_VERSION);
 356         iocp->send_queue_depth = cpu_to_be16(sdev->srq_size);
 357         iocp->rdma_read_depth = 4;
 358         iocp->send_size = cpu_to_be32(srp_max_req_size);
 359         iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
 360                                           1U << 24));
 361         iocp->num_svc_entries = 1;
 362         iocp->op_cap_mask = SRP_SEND_TO_IOC | SRP_SEND_FROM_IOC |
 363                 SRP_RDMA_READ_FROM_IOC | SRP_RDMA_WRITE_FROM_IOC;
 364
 365         mad->mad_hdr.status = 0;
 366 }
 367
 368 /**
 369  * srpt_get_svc_entries() - Write ServiceEntries to a management datagram.
 370  *
 371  * See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
 372  * Specification. See also section B.7, table B.8 in the SRP r16a document.
 373  */
 374 static void srpt_get_svc_entries(u64 ioc_guid,
 375                                  u16 slot, u8 hi, u8 lo, struct ib_dm_mad *mad)
 376 {
 377         struct ib_dm_svc_entries *svc_entries;
 378
 379         WARN_ON(!ioc_guid);
 380
 381         if (!slot || slot > 16) {
 382                 mad->mad_hdr.status
 383                         = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
 384                 return;
 385         }
 386
 387         if (slot > 2 || lo > hi || hi > 1) {
 388                 mad->mad_hdr.status
 389                         = __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
 390                 return;
 391         }
 392
 393         svc_entries = (struct ib_dm_svc_entries *)mad->data;
 394         memset(svc_entries, 0, sizeof *svc_entries);
 395         svc_entries->service_entries[0].id = cpu_to_be64(ioc_guid);
 396         snprintf(svc_entries->service_entries[0].name,
 397                  sizeof(svc_entries->service_entries[0].name),
 398                  "%s%016llx",
 399                  SRP_SERVICE_NAME_PREFIX,
 400                  ioc_guid);
 401
 402         mad->mad_hdr.status = 0;
 403 }
 404
 405 /**
 406  * srpt_mgmt_method_get() - Process a received management datagram.
 407  * @sp:      source port through which the MAD has been received.
 408  * @rq_mad:  received MAD.
 409  * @rsp_mad: response MAD.
 410  */
 411 static void srpt_mgmt_method_get(struct srpt_port *sp, struct ib_mad *rq_mad,
 412                                  struct ib_dm_mad *rsp_mad)
 413 {
 414         u16 attr_id;
 415         u32 slot;
 416         u8 hi, lo;
 417
 418         attr_id = be16_to_cpu(rq_mad->mad_hdr.attr_id);
 419         switch (attr_id) {
 420         case DM_ATTR_CLASS_PORT_INFO:
 421                 srpt_get_class_port_info(rsp_mad);
 422                 break;
 423         case DM_ATTR_IOU_INFO:
 424                 srpt_get_iou(rsp_mad);
 425                 break;
 426         case DM_ATTR_IOC_PROFILE:
 427                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
 428                 srpt_get_ioc(sp, slot, rsp_mad);
 429                 break;
 430         case DM_ATTR_SVC_ENTRIES:
 431                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
 432                 hi = (u8) ((slot >> 8) & 0xff);
 433                 lo = (u8) (slot & 0xff);
 434                 slot = (u16) ((slot >> 16) & 0xffff);
 435                 srpt_get_svc_entries(srpt_service_guid,
 436                                      slot, hi, lo, rsp_mad);
 437                 break;
 438         default:
 439                 rsp_mad->mad_hdr.status =
 440                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
 441                 break;
 442         }
 443 }
 444
 445 /**
 446  * srpt_mad_send_handler() - Post MAD-send callback function.
 447  */
 448 static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
 449                                   struct ib_mad_send_wc *mad_wc)
 450 {
 451         ib_destroy_ah(mad_wc->send_buf->ah);
 452         ib_free_send_mad(mad_wc->send_buf);
 453 }
 454
 455 /**
 456  * srpt_mad_recv_handler() - MAD reception callback function.
 457  */
 458 static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
 459                                   struct ib_mad_recv_wc *mad_wc)
 460 {
 461         struct srpt_port *sport = (struct srpt_port *)mad_agent->context;
 462         struct ib_ah *ah;
 463         struct ib_mad_send_buf *rsp;
 464         struct ib_dm_mad *dm_mad;
 465
 466         if (!mad_wc || !mad_wc->recv_buf.mad)
 467                 return;
 468
 469         ah = ib_create_ah_from_wc(mad_agent->qp->pd, mad_wc->wc,
 470                                   mad_wc->recv_buf.grh, mad_agent->port_num);
 471         if (IS_ERR(ah))
 472                 goto err;
 473
 474         BUILD_BUG_ON(offsetof(struct ib_dm_mad, data) != IB_MGMT_DEVICE_HDR);
 475
 476         rsp = ib_create_send_mad(mad_agent, mad_wc->wc->src_qp,
 477                                  mad_wc->wc->pkey_index, 0,
 478                                  IB_MGMT_DEVICE_HDR, IB_MGMT_DEVICE_DATA,
 479                                  GFP_KERNEL);
 480         if (IS_ERR(rsp))
 481                 goto err_rsp;
 482
 483         rsp->ah = ah;
 484
 485         dm_mad = rsp->mad;
 486         memcpy(dm_mad, mad_wc->recv_buf.mad, sizeof *dm_mad);
 487         dm_mad->mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
 488         dm_mad->mad_hdr.status = 0;
 489
 490         switch (mad_wc->recv_buf.mad->mad_hdr.method) {
 491         case IB_MGMT_METHOD_GET:
 492                 srpt_mgmt_method_get(sport, mad_wc->recv_buf.mad, dm_mad);
 493                 break;
 494         case IB_MGMT_METHOD_SET:
 495                 dm_mad->mad_hdr.status =
 496                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
 497                 break;
 498         default:
 499                 dm_mad->mad_hdr.status =
 500                     __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD);
 501                 break;
 502         }
 503
 504         if (!ib_post_send_mad(rsp, NULL)) {
 505                 ib_free_recv_mad(mad_wc);
 506                 /* will destroy_ah & free_send_mad in send completion */
 507                 return;
 508         }
 509
 510         ib_free_send_mad(rsp);
 511
 512 err_rsp:
 513         ib_destroy_ah(ah);
 514 err:
 515         ib_free_recv_mad(mad_wc);
 516 }
 517
 518 /**
 519  * srpt_refresh_port() - Configure a HCA port.
 520  *
 521  * Enable InfiniBand management datagram processing, update the cached sm_lid,
 522  * lid and gid values, and register a callback function for processing MADs
 523  * on the specified port.
 524  *
 525  * Note: It is safe to call this function more than once for the same port.
 526  */
 527 static int srpt_refresh_port(struct srpt_port *sport)
 528 {
 529         struct ib_mad_reg_req reg_req;
 530         struct ib_port_modify port_modify;
 531         struct ib_port_attr port_attr;
 532         int ret;
 533
 534         memset(&port_modify, 0, sizeof port_modify);
 535         port_modify.set_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
 536         port_modify.clr_port_cap_mask = 0;
 537
 538         ret = ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
 539         if (ret)
 540                 goto err_mod_port;
 541
 542         ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
 543         if (ret)
 544                 goto err_query_port;
 545
 546         sport->sm_lid = port_attr.sm_lid;
 547         sport->lid = port_attr.lid;
 548
 549         ret = ib_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
 550         if (ret)
 551                 goto err_query_port;
 552
 553         if (!sport->mad_agent) {
 554                 memset(&reg_req, 0, sizeof reg_req);
 555                 reg_req.mgmt_class = IB_MGMT_CLASS_DEVICE_MGMT;
 556                 reg_req.mgmt_class_version = IB_MGMT_BASE_VERSION;
 557                 set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
 558                 set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
 559
 560                 sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
 561                                                          sport->port,
 562                                                          IB_QPT_GSI,
 563                                                          &reg_req, 0,
 564                                                          srpt_mad_send_handler,
 565                                                          srpt_mad_recv_handler,
 566                                                          sport);
 567                 if (IS_ERR(sport->mad_agent)) {
 568                         ret = PTR_ERR(sport->mad_agent);
 569                         sport->mad_agent = NULL;
 570                         goto err_query_port;
 571                 }
 572         }
 573
 574         return 0;
 575
 576 err_query_port:
 577
 578         port_modify.set_port_cap_mask = 0;
 579         port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
 580         ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
 581
 582 err_mod_port:
 583
 584         return ret;
 585 }
 586
 587 /**
 588  * srpt_unregister_mad_agent() - Unregister MAD callback functions.
 589  *
 590  * Note: It is safe to call this function more than once for the same device.
 591  */
 592 static void srpt_unregister_mad_agent(struct srpt_device *sdev)
 593 {
 594         struct ib_port_modify port_modify = {
 595                 .clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP,
 596         };
 597         struct srpt_port *sport;
 598         int i;
 599
 600         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
 601                 sport = &sdev->port[i - 1];
 602                 WARN_ON(sport->port != i);
 603                 if (ib_modify_port(sdev->device, i, 0, &port_modify) < 0)
 604                         printk(KERN_ERR "disabling MAD processing failed.\n");
 605                 if (sport->mad_agent) {
 606                         ib_unregister_mad_agent(sport->mad_agent);
 607                         sport->mad_agent = NULL;
 608                 }
 609         }
 610 }
 611
 612 /**
 613  * srpt_alloc_ioctx() - Allocate an SRPT I/O context structure.
 614  */
 615 static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev,
 616                                            int ioctx_size, int dma_size,
 617                                            enum dma_data_direction dir)
 618 {
 619         struct srpt_ioctx *ioctx;
 620
 621         ioctx = kmalloc(ioctx_size, GFP_KERNEL);
 622         if (!ioctx)
 623                 goto err;
 624
 625         ioctx->buf = kmalloc(dma_size, GFP_KERNEL);
 626         if (!ioctx->buf)
 627                 goto err_free_ioctx;
 628
 629         ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf, dma_size, dir);
 630         if (ib_dma_mapping_error(sdev->device, ioctx->dma))
 631                 goto err_free_buf;
 632
 633         return ioctx;
 634
 635 err_free_buf:
 636         kfree(ioctx->buf);
 637 err_free_ioctx:
 638         kfree(ioctx);
 639 err:
 640         return NULL;
 641 }
 642
 643 /**
 644  * srpt_free_ioctx() - Free an SRPT I/O context structure.
 645  */
 646 static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx,
 647                             int dma_size, enum dma_data_direction dir)
 648 {
 649         if (!ioctx)
 650                 return;
 651
 652         ib_dma_unmap_single(sdev->device, ioctx->dma, dma_size, dir);
 653         kfree(ioctx->buf);
 654         kfree(ioctx);
 655 }
 656
 657 /**
 658  * srpt_alloc_ioctx_ring() - Allocate a ring of SRPT I/O context structures.
 659  * @sdev:       Device to allocate the I/O context ring for.
 660  * @ring_size:  Number of elements in the I/O context ring.
 661  * @ioctx_size: I/O context size.
 662  * @dma_size:   DMA buffer size.
 663  * @dir:        DMA data direction.
 664  */
 665 static struct srpt_ioctx **srpt_alloc_ioctx_ring(struct srpt_device *sdev,
 666                                 int ring_size, int ioctx_size,
 667                                 int dma_size, enum dma_data_direction dir)
 668 {
 669         struct srpt_ioctx **ring;
 670         int i;
 671
 672         WARN_ON(ioctx_size != sizeof(struct srpt_recv_ioctx)
 673                 && ioctx_size != sizeof(struct srpt_send_ioctx));
 674
 675         ring = kmalloc(ring_size * sizeof(ring[0]), GFP_KERNEL);
 676         if (!ring)
 677                 goto out;
 678         for (i = 0; i < ring_size; ++i) {
 679                 ring[i] = srpt_alloc_ioctx(sdev, ioctx_size, dma_size, dir);
 680                 if (!ring[i])
 681                         goto err;
 682                 ring[i]->index = i;
 683         }
 684         goto out;
 685
 686 err:
 687         while (--i >= 0)
 688                 srpt_free_ioctx(sdev, ring[i], dma_size, dir);
 689         kfree(ring);
 690         ring = NULL;
 691 out:
 692         return ring;
 693 }
 694
 695 /**
 696  * srpt_free_ioctx_ring() - Free the ring of SRPT I/O context structures.
 697  */
 698 static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
 699                                  struct srpt_device *sdev, int ring_size,
 700                                  int dma_size, enum dma_data_direction dir)
 701 {
 702         int i;
 703
 704         for (i = 0; i < ring_size; ++i)
 705                 srpt_free_ioctx(sdev, ioctx_ring[i], dma_size, dir);
 706         kfree(ioctx_ring);
 707 }
 708
 709 /**
 710  * srpt_get_cmd_state() - Get the state of a SCSI command.
 711  */
 712 static enum srpt_command_state srpt_get_cmd_state(struct srpt_send_ioctx *ioctx)
 713 {
 714         enum srpt_command_state state;
 715         unsigned long flags;
 716
 717         BUG_ON(!ioctx);
 718
 719         spin_lock_irqsave(&ioctx->spinlock, flags);
 720         state = ioctx->state;
 721         spin_unlock_irqrestore(&ioctx->spinlock, flags);
 722         return state;
 723 }
 724
 725 /**
 726  * srpt_set_cmd_state() - Set the state of a SCSI command.
 727  *
 728  * Does not modify the state of aborted commands. Returns the previous command
 729  * state.
 730  */
 731 static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
 732                                                   enum srpt_command_state new)
 733 {
 734         enum srpt_command_state previous;
 735         unsigned long flags;
 736
 737         BUG_ON(!ioctx);
 738
 739         spin_lock_irqsave(&ioctx->spinlock, flags);
 740         previous = ioctx->state;
 741         if (previous != SRPT_STATE_DONE)
 742                 ioctx->state = new;
 743         spin_unlock_irqrestore(&ioctx->spinlock, flags);
 744
 745         return previous;
 746 }
 747
 748 /**
 749  * srpt_test_and_set_cmd_state() - Test and set the state of a command.
 750  *
 751  * Returns true if and only if the previous command state was equal to 'old'.
 752  */
 753 static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
 754                                         enum srpt_command_state old,
 755                                         enum srpt_command_state new)
 756 {
 757         enum srpt_command_state previous;
 758         unsigned long flags;
 759
 760         WARN_ON(!ioctx);
 761         WARN_ON(old == SRPT_STATE_DONE);
 762         WARN_ON(new == SRPT_STATE_NEW);
 763
 764         spin_lock_irqsave(&ioctx->spinlock, flags);
 765         previous = ioctx->state;
 766         if (previous == old)
 767                 ioctx->state = new;
 768         spin_unlock_irqrestore(&ioctx->spinlock, flags);
 769         return previous == old;
 770 }
 771
 772 /**
 773  * srpt_post_recv() - Post an IB receive request.
 774  */
 775 static int srpt_post_recv(struct srpt_device *sdev,
 776                           struct srpt_recv_ioctx *ioctx)
 777 {
 778         struct ib_sge list;
 779         struct ib_recv_wr wr, *bad_wr;
 780
 781         BUG_ON(!sdev);
 782         wr.wr_id = encode_wr_id(SRPT_RECV, ioctx->ioctx.index);
 783
 784         list.addr = ioctx->ioctx.dma;
 785         list.length = srp_max_req_size;
 786         list.lkey = sdev->mr->lkey;
 787
 788         wr.next = NULL;
 789         wr.sg_list = &list;
 790         wr.num_sge = 1;
 791
 792         return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
 793 }
 794
 795 /**
 796  * srpt_post_send() - Post an IB send request.
 797  *
 798  * Returns zero upon success and a non-zero value upon failure.
 799  */
 800 static int srpt_post_send(struct srpt_rdma_ch *ch,
 801                           struct srpt_send_ioctx *ioctx, int len)
 802 {
 803         struct ib_sge list;
 804         struct ib_send_wr wr, *bad_wr;
 805         struct srpt_device *sdev = ch->sport->sdev;
 806         int ret;
 807
 808         atomic_inc(&ch->req_lim);
 809
 810         ret = -ENOMEM;
 811         if (unlikely(atomic_dec_return(&ch->sq_wr_avail) < 0)) {
 812                 printk(KERN_WARNING "IB send queue full (needed 1)\n");
 813                 goto out;
 814         }
 815
 816         ib_dma_sync_single_for_device(sdev->device, ioctx->ioctx.dma, len,
 817                                       DMA_TO_DEVICE);
 818
 819         list.addr = ioctx->ioctx.dma;
 820         list.length = len;
 821         list.lkey = sdev->mr->lkey;
 822
 823         wr.next = NULL;
 824         wr.wr_id = encode_wr_id(SRPT_SEND, ioctx->ioctx.index);
 825         wr.sg_list = &list;
 826         wr.num_sge = 1;
 827         wr.opcode = IB_WR_SEND;
 828         wr.send_flags = IB_SEND_SIGNALED;
 829
 830         ret = ib_post_send(ch->qp, &wr, &bad_wr);
 831
 832 out:
 833         if (ret < 0) {
 834                 atomic_inc(&ch->sq_wr_avail);
 835                 atomic_dec(&ch->req_lim);
 836         }
 837         return ret;
 838 }
 839
 840 /**
 841  * srpt_get_desc_tbl() - Parse the data descriptors of an SRP_CMD request.
 842  * @ioctx: Pointer to the I/O context associated with the request.
 843  * @srp_cmd: Pointer to the SRP_CMD request data.
 844  * @dir: Pointer to the variable to which the transfer direction will be
 845  *   written.
 846  * @data_len: Pointer to the variable to which the total data length of all
 847  *   descriptors in the SRP_CMD request will be written.
 848  *
 849  * This function initializes ioctx->nrbuf and ioctx->r_bufs.
 850  *
 851  * Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
 852  * -ENOMEM when memory allocation fails and zero upon success.
 853  */
 854 static int srpt_get_desc_tbl(struct srpt_send_ioctx *ioctx,
 855                              struct srp_cmd *srp_cmd,
 856                              enum dma_data_direction *dir, u64 *data_len)
 857 {
 858         struct srp_indirect_buf *idb;
 859         struct srp_direct_buf *db;
 860         unsigned add_cdb_offset;
 861         int ret;
 862
 863         /*
 864          * The pointer computations below will only be compiled correctly
 865          * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
 866          * whether srp_cmd::add_data has been declared as a byte pointer.
 867          */
 868         BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
 869                      && !__same_type(srp_cmd->add_data[0], (u8)0));
 870
 871         BUG_ON(!dir);
 872         BUG_ON(!data_len);
 873
 874         ret = 0;
 875         *data_len = 0;
 876
 877         /*
 878          * The lower four bits of the buffer format field contain the DATA-IN
 879          * buffer descriptor format, and the highest four bits contain the
 880          * DATA-OUT buffer descriptor format.
 881          */
 882         *dir = DMA_NONE;
 883         if (srp_cmd->buf_fmt & 0xf)
 884                 /* DATA-IN: transfer data from target to initiator (read). */
 885                 *dir = DMA_FROM_DEVICE;
 886         else if (srp_cmd->buf_fmt >> 4)
 887                 /* DATA-OUT: transfer data from initiator to target (write). */
 888                 *dir = DMA_TO_DEVICE;
 889
 890         /*
 891          * According to the SRP spec, the lower two bits of the 'ADDITIONAL
 892          * CDB LENGTH' field are reserved and the size in bytes of this field
 893          * is four times the value specified in bits 3..7. Hence the "& ~3".
 894          */
 895         add_cdb_offset = srp_cmd->add_cdb_len & ~3;
 896         if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
 897             ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
 898                 ioctx->n_rbuf = 1;
 899                 ioctx->rbufs = &ioctx->single_rbuf;
 900
 901                 db = (struct srp_direct_buf *)(srp_cmd->add_data
 902                                                + add_cdb_offset);
 903                 memcpy(ioctx->rbufs, db, sizeof *db);
 904                 *data_len = be32_to_cpu(db->len);
 905         } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
 906                    ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
 907                 idb = (struct srp_indirect_buf *)(srp_cmd->add_data
 908                                                   + add_cdb_offset);
 909
 910                 ioctx->n_rbuf = be32_to_cpu(idb->table_desc.len) / sizeof *db;
 911
 912                 if (ioctx->n_rbuf >
 913                     (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
 914                         printk(KERN_ERR "received unsupported SRP_CMD request"
 915                                " type (%u out + %u in != %u / %zu)\n",
 916                                srp_cmd->data_out_desc_cnt,
 917                                srp_cmd->data_in_desc_cnt,
 918                                be32_to_cpu(idb->table_desc.len),
 919                                sizeof(*db));
 920                         ioctx->n_rbuf = 0;
 921                         ret = -EINVAL;
 922                         goto out;
 923                 }
 924
 925                 if (ioctx->n_rbuf == 1)
 926                         ioctx->rbufs = &ioctx->single_rbuf;
 927                 else {
 928                         ioctx->rbufs =
 929                                 kmalloc(ioctx->n_rbuf * sizeof *db, GFP_ATOMIC);
 930                         if (!ioctx->rbufs) {
 931                                 ioctx->n_rbuf = 0;
 932                                 ret = -ENOMEM;
 933                                 goto out;
 934                         }
 935                 }
 936
 937                 db = idb->desc_list;
 938                 memcpy(ioctx->rbufs, db, ioctx->n_rbuf * sizeof *db);
 939                 *data_len = be32_to_cpu(idb->len);
 940         }
 941 out:
 942         return ret;
 943 }
 944
 945 /**
 946  * srpt_init_ch_qp() - Initialize queue pair attributes.
 947  *
 948  * Initialized the attributes of queue pair 'qp' by allowing local write,
 949  * remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
 950  */
 951 static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
 952 {
 953         struct ib_qp_attr *attr;
 954         int ret;
 955
 956         attr = kzalloc(sizeof *attr, GFP_KERNEL);
 957         if (!attr)
 958                 return -ENOMEM;
 959
 960         attr->qp_state = IB_QPS_INIT;
 961         attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
 962             IB_ACCESS_REMOTE_WRITE;
 963         attr->port_num = ch->sport->port;
 964         attr->pkey_index = 0;
 965
 966         ret = ib_modify_qp(qp, attr,
 967                            IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
 968                            IB_QP_PKEY_INDEX);
 969
 970         kfree(attr);
 971         return ret;
 972 }
 973
 974 /**
 975  * srpt_ch_qp_rtr() - Change the state of a channel to 'ready to receive' (RTR).
 976  * @ch: channel of the queue pair.
 977  * @qp: queue pair to change the state of.
 978  *
 979  * Returns zero upon success and a negative value upon failure.
 980  *
 981  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
 982  * If this structure ever becomes larger, it might be necessary to allocate
 983  * it dynamically instead of on the stack.
 984  */
 985 static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
 986 {
 987         struct ib_qp_attr qp_attr;
 988         int attr_mask;
 989         int ret;
 990
 991         qp_attr.qp_state = IB_QPS_RTR;
 992         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
 993         if (ret)
 994                 goto out;
 995
 996         qp_attr.max_dest_rd_atomic = 4;
 997
 998         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
 999
1000 out:
1001         return ret;
1002 }
1003
1004 /**
1005  * srpt_ch_qp_rts() - Change the state of a channel to 'ready to send' (RTS).
1006  * @ch: channel of the queue pair.
1007  * @qp: queue pair to change the state of.
1008  *
1009  * Returns zero upon success and a negative value upon failure.
1010  *
1011  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1012  * If this structure ever becomes larger, it might be necessary to allocate
1013  * it dynamically instead of on the stack.
1014  */
1015 static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1016 {
1017         struct ib_qp_attr qp_attr;
1018         int attr_mask;
1019         int ret;
1020
1021         qp_attr.qp_state = IB_QPS_RTS;
1022         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
1023         if (ret)
1024                 goto out;
1025
1026         qp_attr.max_rd_atomic = 4;
1027
1028         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1029
1030 out:
1031         return ret;
1032 }
1033
1034 /**
1035  * srpt_ch_qp_err() - Set the channel queue pair state to 'error'.
1036  */
1037 static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
1038 {
1039         struct ib_qp_attr qp_attr;
1040
1041         qp_attr.qp_state = IB_QPS_ERR;
1042         return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
1043 }
1044
1045 /**
1046  * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
1047  */
1048 static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1049                                     struct srpt_send_ioctx *ioctx)
1050 {
1051         struct scatterlist *sg;
1052         enum dma_data_direction dir;
1053
1054         BUG_ON(!ch);
1055         BUG_ON(!ioctx);
1056         BUG_ON(ioctx->n_rdma && !ioctx->rdma_ius);
1057
1058         while (ioctx->n_rdma)
1059                 kfree(ioctx->rdma_ius[--ioctx->n_rdma].sge);
1060
1061         kfree(ioctx->rdma_ius);
1062         ioctx->rdma_ius = NULL;
1063
1064         if (ioctx->mapped_sg_count) {
1065                 sg = ioctx->sg;
1066                 WARN_ON(!sg);
1067                 dir = ioctx->cmd.data_direction;
1068                 BUG_ON(dir == DMA_NONE);
1069                 ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
1070                                 opposite_dma_dir(dir));
1071                 ioctx->mapped_sg_count = 0;
1072         }
1073 }
1074
1075 /**
1076  * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
1077  */
1078 static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1079                                  struct srpt_send_ioctx *ioctx)
1080 {
1081         struct se_cmd *cmd;
1082         struct scatterlist *sg, *sg_orig;
1083         int sg_cnt;
1084         enum dma_data_direction dir;
1085         struct rdma_iu *riu;
1086         struct srp_direct_buf *db;
1087         dma_addr_t dma_addr;
1088         struct ib_sge *sge;
1089         u64 raddr;
1090         u32 rsize;
1091         u32 tsize;
1092         u32 dma_len;
1093         int count, nrdma;
1094         int i, j, k;
1095
1096         BUG_ON(!ch);
1097         BUG_ON(!ioctx);
1098         cmd = &ioctx->cmd;
1099         dir = cmd->data_direction;
1100         BUG_ON(dir == DMA_NONE);
1101
1102         transport_do_task_sg_chain(cmd);
1103         ioctx->sg = sg = sg_orig = cmd->t_tasks_sg_chained;
1104         ioctx->sg_cnt = sg_cnt = cmd->t_tasks_sg_chained_no;
1105
1106         count = ib_dma_map_sg(ch->sport->sdev->device, sg, sg_cnt,
1107                               opposite_dma_dir(dir));
1108         if (unlikely(!count))
1109                 return -EAGAIN;
1110
1111         ioctx->mapped_sg_count = count;
1112
1113         if (ioctx->rdma_ius && ioctx->n_rdma_ius)
1114                 nrdma = ioctx->n_rdma_ius;
1115         else {
1116                 nrdma = (count + SRPT_DEF_SG_PER_WQE - 1) / SRPT_DEF_SG_PER_WQE
1117                         + ioctx->n_rbuf;
1118
1119                 ioctx->rdma_ius = kzalloc(nrdma * sizeof *riu, GFP_KERNEL);
1120                 if (!ioctx->rdma_ius)
1121                         goto free_mem;
1122
1123                 ioctx->n_rdma_ius = nrdma;
1124         }
1125
1126         db = ioctx->rbufs;
1127         tsize = cmd->data_length;
1128         dma_len = sg_dma_len(&sg[0]);
1129         riu = ioctx->rdma_ius;
1130
1131         /*
1132          * For each remote desc - calculate the #ib_sge.
1133          * If #ib_sge < SRPT_DEF_SG_PER_WQE per rdma operation then
1134          *      each remote desc rdma_iu is required a rdma wr;
1135          * else
1136          *      we need to allocate extra rdma_iu to carry extra #ib_sge in
1137          *      another rdma wr
1138          */
1139         for (i = 0, j = 0;
1140              j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1141                 rsize = be32_to_cpu(db->len);
1142                 raddr = be64_to_cpu(db->va);
1143                 riu->raddr = raddr;
1144                 riu->rkey = be32_to_cpu(db->key);
1145                 riu->sge_cnt = 0;
1146
1147                 /* calculate how many sge required for this remote_buf */
1148                 while (rsize > 0 && tsize > 0) {
1149
1150                         if (rsize >= dma_len) {
1151                                 tsize -= dma_len;
1152                                 rsize -= dma_len;
1153                                 raddr += dma_len;
1154
1155                                 if (tsize > 0) {
1156                                         ++j;
1157                                         if (j < count) {
1158                                                 sg = sg_next(sg);
1159                                                 dma_len = sg_dma_len(sg);
1160                                         }
1161                                 }
1162                         } else {
1163                                 tsize -= rsize;
1164                                 dma_len -= rsize;
1165                                 rsize = 0;
1166                         }
1167
1168                         ++riu->sge_cnt;
1169
1170                         if (rsize > 0 && riu->sge_cnt == SRPT_DEF_SG_PER_WQE) {
1171                                 ++ioctx->n_rdma;
1172                                 riu->sge =
1173                                     kmalloc(riu->sge_cnt * sizeof *riu->sge,
1174                                             GFP_KERNEL);
1175                                 if (!riu->sge)
1176                                         goto free_mem;
1177
1178                                 ++riu;
1179                                 riu->sge_cnt = 0;
1180                                 riu->raddr = raddr;
1181                                 riu->rkey = be32_to_cpu(db->key);
1182                         }
1183                 }
1184
1185                 ++ioctx->n_rdma;
1186                 riu->sge = kmalloc(riu->sge_cnt * sizeof *riu->sge,
1187                                    GFP_KERNEL);
1188                 if (!riu->sge)
1189                         goto free_mem;
1190         }
1191
1192         db = ioctx->rbufs;
1193         tsize = cmd->data_length;
1194         riu = ioctx->rdma_ius;
1195         sg = sg_orig;
1196         dma_len = sg_dma_len(&sg[0]);
1197         dma_addr = sg_dma_address(&sg[0]);
1198
1199         /* this second loop is really mapped sg_addres to rdma_iu->ib_sge */
1200         for (i = 0, j = 0;
1201              j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1202                 rsize = be32_to_cpu(db->len);
1203                 sge = riu->sge;
1204                 k = 0;
1205
1206                 while (rsize > 0 && tsize > 0) {
1207                         sge->addr = dma_addr;
1208                         sge->lkey = ch->sport->sdev->mr->lkey;
1209
1210                         if (rsize >= dma_len) {
1211                                 sge->length =
1212                                         (tsize < dma_len) ? tsize : dma_len;
1213                                 tsize -= dma_len;
1214                                 rsize -= dma_len;
1215
1216                                 if (tsize > 0) {
1217                                         ++j;
1218                                         if (j < count) {
1219                                                 sg = sg_next(sg);
1220                                                 dma_len = sg_dma_len(sg);
1221                                                 dma_addr = sg_dma_address(sg);
1222                                         }
1223                                 }
1224                         } else {
1225                                 sge->length = (tsize < rsize) ? tsize : rsize;
1226                                 tsize -= rsize;
1227                                 dma_len -= rsize;
1228                                 dma_addr += rsize;
1229                                 rsize = 0;
1230                         }
1231
1232                         ++k;
1233                         if (k == riu->sge_cnt && rsize > 0 && tsize > 0) {
1234                                 ++riu;
1235                                 sge = riu->sge;
1236                                 k = 0;
1237                         } else if (rsize > 0 && tsize > 0)
1238                                 ++sge;
1239                 }
1240         }
1241
1242         return 0;
1243
1244 free_mem:
1245         srpt_unmap_sg_to_ib_sge(ch, ioctx);
1246
1247         return -ENOMEM;
1248 }
1249
1250 /**
1251  * srpt_get_send_ioctx() - Obtain an I/O context for sending to the initiator.
1252  */
1253 static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
1254 {
1255         struct srpt_send_ioctx *ioctx;
1256         unsigned long flags;
1257
1258         BUG_ON(!ch);
1259
1260         ioctx = NULL;
1261         spin_lock_irqsave(&ch->spinlock, flags);
1262         if (!list_empty(&ch->free_list)) {
1263                 ioctx = list_first_entry(&ch->free_list,
1264                                          struct srpt_send_ioctx, free_list);
1265                 list_del(&ioctx->free_list);
1266         }
1267         spin_unlock_irqrestore(&ch->spinlock, flags);
1268
1269         if (!ioctx)
1270                 return ioctx;
1271
1272         BUG_ON(ioctx->ch != ch);
1273         kref_init(&ioctx->kref);
1274         spin_lock_init(&ioctx->spinlock);
1275         ioctx->state = SRPT_STATE_NEW;
1276         ioctx->n_rbuf = 0;
1277         ioctx->rbufs = NULL;
1278         ioctx->n_rdma = 0;
1279         ioctx->n_rdma_ius = 0;
1280         ioctx->rdma_ius = NULL;
1281         ioctx->mapped_sg_count = 0;
1282         init_completion(&ioctx->tx_done);
1283         ioctx->queue_status_only = false;
1284         /*
1285          * transport_init_se_cmd() does not initialize all fields, so do it
1286          * here.
1287          */
1288         memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
1289         memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
1290
1291         return ioctx;
1292 }
1293
1294 /**
1295  * srpt_put_send_ioctx() - Free up resources.
1296  */
1297 static void srpt_put_send_ioctx(struct srpt_send_ioctx *ioctx)
1298 {
1299         struct srpt_rdma_ch *ch;
1300         unsigned long flags;
1301
1302         BUG_ON(!ioctx);
1303         ch = ioctx->ch;
1304         BUG_ON(!ch);
1305
1306         WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
1307
1308         srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1309         transport_generic_free_cmd(&ioctx->cmd, 0);
1310
1311         if (ioctx->n_rbuf > 1) {
1312                 kfree(ioctx->rbufs);
1313                 ioctx->rbufs = NULL;
1314                 ioctx->n_rbuf = 0;
1315         }
1316
1317         spin_lock_irqsave(&ch->spinlock, flags);
1318         list_add(&ioctx->free_list, &ch->free_list);
1319         spin_unlock_irqrestore(&ch->spinlock, flags);
1320 }
1321
1322 static void srpt_put_send_ioctx_kref(struct kref *kref)
1323 {
1324         srpt_put_send_ioctx(container_of(kref, struct srpt_send_ioctx, kref));
1325 }
1326
1327 /**
1328  * srpt_abort_cmd() - Abort a SCSI command.
1329  * @ioctx:   I/O context associated with the SCSI command.
1330  * @context: Preferred execution context.
1331  */
1332 static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
1333 {
1334         enum srpt_command_state state;
1335         unsigned long flags;
1336
1337         BUG_ON(!ioctx);
1338
1339         /*
1340          * If the command is in a state where the target core is waiting for
1341          * the ib_srpt driver, change the state to the next state. Changing
1342          * the state of the command from SRPT_STATE_NEED_DATA to
1343          * SRPT_STATE_DATA_IN ensures that srpt_xmit_response() will call this
1344          * function a second time.
1345          */
1346
1347         spin_lock_irqsave(&ioctx->spinlock, flags);
1348         state = ioctx->state;
1349         switch (state) {
1350         case SRPT_STATE_NEED_DATA:
1351                 ioctx->state = SRPT_STATE_DATA_IN;
1352                 break;
1353         case SRPT_STATE_DATA_IN:
1354         case SRPT_STATE_CMD_RSP_SENT:
1355         case SRPT_STATE_MGMT_RSP_SENT:
1356                 ioctx->state = SRPT_STATE_DONE;
1357                 break;
1358         default:
1359                 break;
1360         }
1361         spin_unlock_irqrestore(&ioctx->spinlock, flags);
1362
1363         if (state == SRPT_STATE_DONE)
1364                 goto out;
1365
1366         pr_debug("Aborting cmd with state %d and tag %lld\n", state,
1367                  ioctx->tag);
1368
1369         switch (state) {
1370         case SRPT_STATE_NEW:
1371         case SRPT_STATE_DATA_IN:
1372         case SRPT_STATE_MGMT:
1373                 /*
1374                  * Do nothing - defer abort processing until
1375                  * srpt_queue_response() is invoked.
1376                  */
1377                 WARN_ON(!transport_check_aborted_status(&ioctx->cmd, false));
1378                 break;
1379         case SRPT_STATE_NEED_DATA:
1380                 /* DMA_TO_DEVICE (write) - RDMA read error. */
1381                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1382                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1383                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1384                 transport_generic_handle_data(&ioctx->cmd);
1385                 break;
1386         case SRPT_STATE_CMD_RSP_SENT:
1387                 /*
1388                  * SRP_RSP sending failed or the SRP_RSP send completion has
1389                  * not been received in time.
1390                  */
1391                 srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1392                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1393                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1394                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1395                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1396                 break;
1397         case SRPT_STATE_MGMT_RSP_SENT:
1398                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1399                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1400                 break;
1401         default:
1402                 WARN_ON("ERROR: unexpected command state");
1403                 break;
1404         }
1405
1406 out:
1407         return state;
1408 }
1409
1410 /**
1411  * srpt_handle_send_err_comp() - Process an IB_WC_SEND error completion.
1412  */
1413 static void srpt_handle_send_err_comp(struct srpt_rdma_ch *ch, u64 wr_id)
1414 {
1415         struct srpt_send_ioctx *ioctx;
1416         enum srpt_command_state state;
1417         struct se_cmd *cmd;
1418         u32 index;
1419
1420         atomic_inc(&ch->sq_wr_avail);
1421
1422         index = idx_from_wr_id(wr_id);
1423         ioctx = ch->ioctx_ring[index];
1424         state = srpt_get_cmd_state(ioctx);
1425         cmd = &ioctx->cmd;
1426
1427         WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1428                 && state != SRPT_STATE_MGMT_RSP_SENT
1429                 && state != SRPT_STATE_NEED_DATA
1430                 && state != SRPT_STATE_DONE);
1431
1432         /* If SRP_RSP sending failed, undo the ch->req_lim change. */
1433         if (state == SRPT_STATE_CMD_RSP_SENT
1434             || state == SRPT_STATE_MGMT_RSP_SENT)
1435                 atomic_dec(&ch->req_lim);
1436
1437         srpt_abort_cmd(ioctx);
1438 }
1439
1440 /**
1441  * srpt_handle_send_comp() - Process an IB send completion notification.
1442  */
1443 static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
1444                                   struct srpt_send_ioctx *ioctx)
1445 {
1446         enum srpt_command_state state;
1447
1448         atomic_inc(&ch->sq_wr_avail);
1449
1450         state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1451
1452         if (WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1453                     && state != SRPT_STATE_MGMT_RSP_SENT
1454                     && state != SRPT_STATE_DONE))
1455                 pr_debug("state = %d\n", state);
1456
1457         if (state != SRPT_STATE_DONE)
1458                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1459         else
1460                 printk(KERN_ERR "IB completion has been received too late for"
1461                        " wr_id = %u.\n", ioctx->ioctx.index);
1462 }
1463
1464 /**
1465  * srpt_handle_rdma_comp() - Process an IB RDMA completion notification.
1466  *
1467  * Note: transport_generic_handle_data() is asynchronous so unmapping the
1468  * data that has been transferred via IB RDMA must be postponed until the
1469  * check_stop_free() callback.
1470  */
1471 static void srpt_handle_rdma_comp(struct srpt_rdma_ch *ch,
1472                                   struct srpt_send_ioctx *ioctx,
1473                                   enum srpt_opcode opcode)
1474 {
1475         WARN_ON(ioctx->n_rdma <= 0);
1476         atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1477
1478         if (opcode == SRPT_RDMA_READ_LAST) {
1479                 if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
1480                                                 SRPT_STATE_DATA_IN))
1481                         transport_generic_handle_data(&ioctx->cmd);
1482                 else
1483                         printk(KERN_ERR "%s[%d]: wrong state = %d\n", __func__,
1484                                __LINE__, srpt_get_cmd_state(ioctx));
1485         } else if (opcode == SRPT_RDMA_ABORT) {
1486                 ioctx->rdma_aborted = true;
1487         } else {
1488                 WARN(true, "unexpected opcode %d\n", opcode);
1489         }
1490 }
1491
1492 /**
1493  * srpt_handle_rdma_err_comp() - Process an IB RDMA error completion.
1494  */
1495 static void srpt_handle_rdma_err_comp(struct srpt_rdma_ch *ch,
1496                                       struct srpt_send_ioctx *ioctx,
1497                                       enum srpt_opcode opcode)
1498 {
1499         struct se_cmd *cmd;
1500         enum srpt_command_state state;
1501         unsigned long flags;
1502
1503         cmd = &ioctx->cmd;
1504         state = srpt_get_cmd_state(ioctx);
1505         switch (opcode) {
1506         case SRPT_RDMA_READ_LAST:
1507                 if (ioctx->n_rdma <= 0) {
1508                         printk(KERN_ERR "Received invalid RDMA read"
1509                                " error completion with idx %d\n",
1510                                ioctx->ioctx.index);
1511                         break;
1512                 }
1513                 atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1514                 if (state == SRPT_STATE_NEED_DATA)
1515                         srpt_abort_cmd(ioctx);
1516                 else
1517                         printk(KERN_ERR "%s[%d]: wrong state = %d\n",
1518                                __func__, __LINE__, state);
1519                 break;
1520         case SRPT_RDMA_WRITE_LAST:
1521                 spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1522                 ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1523                 spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1524                 break;
1525         default:
1526                 printk(KERN_ERR "%s[%d]: opcode = %u\n", __func__,
1527                        __LINE__, opcode);
1528                 break;
1529         }
1530 }
1531
1532 /**
1533  * srpt_build_cmd_rsp() - Build an SRP_RSP response.
1534  * @ch: RDMA channel through which the request has been received.
1535  * @ioctx: I/O context associated with the SRP_CMD request. The response will
1536  *   be built in the buffer ioctx->buf points at and hence this function will
1537  *   overwrite the request data.
1538  * @tag: tag of the request for which this response is being generated.
1539  * @status: value for the STATUS field of the SRP_RSP information unit.
1540  *
1541  * Returns the size in bytes of the SRP_RSP response.
1542  *
1543  * An SRP_RSP response contains a SCSI status or service response. See also
1544  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1545  * response. See also SPC-2 for more information about sense data.
1546  */
1547 static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
1548                               struct srpt_send_ioctx *ioctx, u64 tag,
1549                               int status)
1550 {
1551         struct srp_rsp *srp_rsp;
1552         const u8 *sense_data;
1553         int sense_data_len, max_sense_len;
1554
1555         /*
1556          * The lowest bit of all SAM-3 status codes is zero (see also
1557          * paragraph 5.3 in SAM-3).
1558          */
1559         WARN_ON(status & 1);
1560
1561         srp_rsp = ioctx->ioctx.buf;
1562         BUG_ON(!srp_rsp);
1563
1564         sense_data = ioctx->sense_data;
1565         sense_data_len = ioctx->cmd.scsi_sense_length;
1566         WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
1567
1568         memset(srp_rsp, 0, sizeof *srp_rsp);
1569         srp_rsp->opcode = SRP_RSP;
1570         srp_rsp->req_lim_delta =
1571                 __constant_cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1572         srp_rsp->tag = tag;
1573         srp_rsp->status = status;
1574
1575         if (sense_data_len) {
1576                 BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
1577                 max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
1578                 if (sense_data_len > max_sense_len) {
1579                         printk(KERN_WARNING "truncated sense data from %d to %d"
1580                                " bytes\n", sense_data_len, max_sense_len);
1581                         sense_data_len = max_sense_len;
1582                 }
1583
1584                 srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
1585                 srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
1586                 memcpy(srp_rsp + 1, sense_data, sense_data_len);
1587         }
1588
1589         return sizeof(*srp_rsp) + sense_data_len;
1590 }
1591
1592 /**
1593  * srpt_build_tskmgmt_rsp() - Build a task management response.
1594  * @ch:       RDMA channel through which the request has been received.
1595  * @ioctx:    I/O context in which the SRP_RSP response will be built.
1596  * @rsp_code: RSP_CODE that will be stored in the response.
1597  * @tag:      Tag of the request for which this response is being generated.
1598  *
1599  * Returns the size in bytes of the SRP_RSP response.
1600  *
1601  * An SRP_RSP response contains a SCSI status or service response. See also
1602  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1603  * response.
1604  */
1605 static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
1606                                   struct srpt_send_ioctx *ioctx,
1607                                   u8 rsp_code, u64 tag)
1608 {
1609         struct srp_rsp *srp_rsp;
1610         int resp_data_len;
1611         int resp_len;
1612
1613         resp_data_len = (rsp_code == SRP_TSK_MGMT_SUCCESS) ? 0 : 4;
1614         resp_len = sizeof(*srp_rsp) + resp_data_len;
1615
1616         srp_rsp = ioctx->ioctx.buf;
1617         BUG_ON(!srp_rsp);
1618         memset(srp_rsp, 0, sizeof *srp_rsp);
1619
1620         srp_rsp->opcode = SRP_RSP;
1621         srp_rsp->req_lim_delta = __constant_cpu_to_be32(1
1622                                     + atomic_xchg(&ch->req_lim_delta, 0));
1623         srp_rsp->tag = tag;
1624
1625         if (rsp_code != SRP_TSK_MGMT_SUCCESS) {
1626                 srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
1627                 srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
1628                 srp_rsp->data[3] = rsp_code;
1629         }
1630
1631         return resp_len;
1632 }
1633
1634 #define NO_SUCH_LUN ((uint64_t)-1LL)
1635
1636 /*
1637  * SCSI LUN addressing method. See also SAM-2 and the section about
1638  * eight byte LUNs.
1639  */
1640 enum scsi_lun_addr_method {
1641         SCSI_LUN_ADDR_METHOD_PERIPHERAL   = 0,
1642         SCSI_LUN_ADDR_METHOD_FLAT         = 1,
1643         SCSI_LUN_ADDR_METHOD_LUN          = 2,
1644         SCSI_LUN_ADDR_METHOD_EXTENDED_LUN = 3,
1645 };
1646
1647 /*
1648  * srpt_unpack_lun() - Convert from network LUN to linear LUN.
1649  *
1650  * Convert an 2-byte, 4-byte, 6-byte or 8-byte LUN structure in network byte
1651  * order (big endian) to a linear LUN. Supports three LUN addressing methods:
1652  * peripheral, flat and logical unit. See also SAM-2, section 4.9.4 (page 40).
1653  */
1654 static uint64_t srpt_unpack_lun(const uint8_t *lun, int len)
1655 {
1656         uint64_t res = NO_SUCH_LUN;
1657         int addressing_method;
1658
1659         if (unlikely(len < 2)) {
1660                 printk(KERN_ERR "Illegal LUN length %d, expected 2 bytes or "
1661                        "more", len);
1662                 goto out;
1663         }
1664
1665         switch (len) {
1666         case 8:
1667                 if ((*((__be64 *)lun) &
1668                      __constant_cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
1669                         goto out_err;
1670                 break;
1671         case 4:
1672                 if (*((__be16 *)&lun[2]) != 0)
1673                         goto out_err;
1674                 break;
1675         case 6:
1676                 if (*((__be32 *)&lun[2]) != 0)
1677                         goto out_err;
1678                 break;
1679         case 2:
1680                 break;
1681         default:
1682                 goto out_err;
1683         }
1684
1685         addressing_method = (*lun) >> 6; /* highest two bits of byte 0 */
1686         switch (addressing_method) {
1687         case SCSI_LUN_ADDR_METHOD_PERIPHERAL:
1688         case SCSI_LUN_ADDR_METHOD_FLAT:
1689         case SCSI_LUN_ADDR_METHOD_LUN:
1690                 res = *(lun + 1) | (((*lun) & 0x3f) << 8);
1691                 break;
1692
1693         case SCSI_LUN_ADDR_METHOD_EXTENDED_LUN:
1694         default:
1695                 printk(KERN_ERR "Unimplemented LUN addressing method %u",
1696                        addressing_method);
1697                 break;
1698         }
1699
1700 out:
1701         return res;
1702
1703 out_err:
1704         printk(KERN_ERR "Support for multi-level LUNs has not yet been"
1705                " implemented");
1706         goto out;
1707 }
1708
1709 static int srpt_check_stop_free(struct se_cmd *cmd)
1710 {
1711         struct srpt_send_ioctx *ioctx;
1712
1713         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
1714         return kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1715 }
1716
1717 /**
1718  * srpt_handle_cmd() - Process SRP_CMD.
1719  */
1720 static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
1721                            struct srpt_recv_ioctx *recv_ioctx,
1722                            struct srpt_send_ioctx *send_ioctx)
1723 {
1724         struct se_cmd *cmd;
1725         struct srp_cmd *srp_cmd;
1726         uint64_t unpacked_lun;
1727         u64 data_len;
1728         enum dma_data_direction dir;
1729         int ret;
1730
1731         BUG_ON(!send_ioctx);
1732
1733         srp_cmd = recv_ioctx->ioctx.buf;
1734         kref_get(&send_ioctx->kref);
1735         cmd = &send_ioctx->cmd;
1736         send_ioctx->tag = srp_cmd->tag;
1737
1738         switch (srp_cmd->task_attr) {
1739         case SRP_CMD_SIMPLE_Q:
1740                 cmd->sam_task_attr = MSG_SIMPLE_TAG;
1741                 break;
1742         case SRP_CMD_ORDERED_Q:
1743         default:
1744                 cmd->sam_task_attr = MSG_ORDERED_TAG;
1745                 break;
1746         case SRP_CMD_HEAD_OF_Q:
1747                 cmd->sam_task_attr = MSG_HEAD_TAG;
1748                 break;
1749         case SRP_CMD_ACA:
1750                 cmd->sam_task_attr = MSG_ACA_TAG;
1751                 break;
1752         }
1753
1754         ret = srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len);
1755         if (ret) {
1756                 printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
1757                        srp_cmd->tag);
1758                 cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1759                 cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1760                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1761                 goto send_sense;
1762         }
1763
1764         cmd->data_length = data_len;
1765         cmd->data_direction = dir;
1766         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
1767                                        sizeof(srp_cmd->lun));
1768         if (transport_lookup_cmd_lun(cmd, unpacked_lun) < 0) {
1769                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1770                 goto send_sense;
1771         }
1772         ret = transport_generic_allocate_tasks(cmd, srp_cmd->cdb);
1773         if (ret < 0) {
1774                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1775                 if (cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT) {
1776                         srpt_queue_status(cmd);
1777                         return 0;
1778                 } else
1779                         goto send_sense;
1780         }
1781
1782         transport_handle_cdb_direct(cmd);
1783         return 0;
1784
1785 send_sense:
1786         transport_send_check_condition_and_sense(cmd, cmd->scsi_sense_reason,
1787                                                  0);
1788         return -1;
1789 }
1790
1791 /**
1792  * srpt_rx_mgmt_fn_tag() - Process a task management function by tag.
1793  * @ch: RDMA channel of the task management request.
1794  * @fn: Task management function to perform.
1795  * @req_tag: Tag of the SRP task management request.
1796  * @mgmt_ioctx: I/O context of the task management request.
1797  *
1798  * Returns zero if the target core will process the task management
1799  * request asynchronously.
1800  *
1801  * Note: It is assumed that the initiator serializes tag-based task management
1802  * requests.
1803  */
1804 static int srpt_rx_mgmt_fn_tag(struct srpt_send_ioctx *ioctx, u64 tag)
1805 {
1806         struct srpt_device *sdev;
1807         struct srpt_rdma_ch *ch;
1808         struct srpt_send_ioctx *target;
1809         int ret, i;
1810
1811         ret = -EINVAL;
1812         ch = ioctx->ch;
1813         BUG_ON(!ch);
1814         BUG_ON(!ch->sport);
1815         sdev = ch->sport->sdev;
1816         BUG_ON(!sdev);
1817         spin_lock_irq(&sdev->spinlock);
1818         for (i = 0; i < ch->rq_size; ++i) {
1819                 target = ch->ioctx_ring[i];
1820                 if (target->cmd.se_lun == ioctx->cmd.se_lun &&
1821                     target->tag == tag &&
1822                     srpt_get_cmd_state(target) != SRPT_STATE_DONE) {
1823                         ret = 0;
1824                         /* now let the target core abort &target->cmd; */
1825                         break;
1826                 }
1827         }
1828         spin_unlock_irq(&sdev->spinlock);
1829         return ret;
1830 }
1831
1832 static int srp_tmr_to_tcm(int fn)
1833 {
1834         switch (fn) {
1835         case SRP_TSK_ABORT_TASK:
1836                 return TMR_ABORT_TASK;
1837         case SRP_TSK_ABORT_TASK_SET:
1838                 return TMR_ABORT_TASK_SET;
1839         case SRP_TSK_CLEAR_TASK_SET:
1840                 return TMR_CLEAR_TASK_SET;
1841         case SRP_TSK_LUN_RESET:
1842                 return TMR_LUN_RESET;
1843         case SRP_TSK_CLEAR_ACA:
1844                 return TMR_CLEAR_ACA;
1845         default:
1846                 return -1;
1847         }
1848 }
1849
1850 /**
1851  * srpt_handle_tsk_mgmt() - Process an SRP_TSK_MGMT information unit.
1852  *
1853  * Returns 0 if and only if the request will be processed by the target core.
1854  *
1855  * For more information about SRP_TSK_MGMT information units, see also section
1856  * 6.7 in the SRP r16a document.
1857  */
1858 static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
1859                                  struct srpt_recv_ioctx *recv_ioctx,
1860                                  struct srpt_send_ioctx *send_ioctx)
1861 {
1862         struct srp_tsk_mgmt *srp_tsk;
1863         struct se_cmd *cmd;
1864         uint64_t unpacked_lun;
1865         int tcm_tmr;
1866         int res;
1867
1868         BUG_ON(!send_ioctx);
1869
1870         srp_tsk = recv_ioctx->ioctx.buf;
1871         cmd = &send_ioctx->cmd;
1872
1873         pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld"
1874                  " cm_id %p sess %p\n", srp_tsk->tsk_mgmt_func,
1875                  srp_tsk->task_tag, srp_tsk->tag, ch->cm_id, ch->sess);
1876
1877         srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
1878         send_ioctx->tag = srp_tsk->tag;
1879         tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
1880         if (tcm_tmr < 0) {
1881                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1882                 send_ioctx->cmd.se_tmr_req->response =
1883                         TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
1884                 goto process_tmr;
1885         }
1886         res = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
1887         if (res < 0) {
1888                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1889                 send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
1890                 goto process_tmr;
1891         }
1892
1893         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_tsk->lun,
1894                                        sizeof(srp_tsk->lun));
1895         res = transport_lookup_tmr_lun(&send_ioctx->cmd, unpacked_lun);
1896         if (res) {
1897                 pr_debug("rejecting TMR for LUN %lld\n", unpacked_lun);
1898                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1899                 send_ioctx->cmd.se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1900                 goto process_tmr;
1901         }
1902
1903         if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
1904                 srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
1905
1906 process_tmr:
1907         kref_get(&send_ioctx->kref);
1908         if (!(send_ioctx->cmd.se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
1909                 transport_generic_handle_tmr(&send_ioctx->cmd);
1910         else
1911                 transport_send_check_condition_and_sense(cmd,
1912                                                 cmd->scsi_sense_reason, 0);
1913
1914 }
1915
1916 /**
1917  * srpt_handle_new_iu() - Process a newly received information unit.
1918  * @ch:    RDMA channel through which the information unit has been received.
1919  * @ioctx: SRPT I/O context associated with the information unit.
1920  */
1921 static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
1922                                struct srpt_recv_ioctx *recv_ioctx,
1923                                struct srpt_send_ioctx *send_ioctx)
1924 {
1925         struct srp_cmd *srp_cmd;
1926         enum rdma_ch_state ch_state;
1927
1928         BUG_ON(!ch);
1929         BUG_ON(!recv_ioctx);
1930
1931         ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
1932                                    recv_ioctx->ioctx.dma, srp_max_req_size,
1933                                    DMA_FROM_DEVICE);
1934
1935         ch_state = srpt_get_ch_state(ch);
1936         if (unlikely(ch_state == CH_CONNECTING)) {
1937                 list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
1938                 goto out;
1939         }
1940
1941         if (unlikely(ch_state != CH_LIVE))
1942                 goto out;
1943
1944         srp_cmd = recv_ioctx->ioctx.buf;
1945         if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT) {
1946                 if (!send_ioctx)
1947                         send_ioctx = srpt_get_send_ioctx(ch);
1948                 if (unlikely(!send_ioctx)) {
1949                         list_add_tail(&recv_ioctx->wait_list,
1950                                       &ch->cmd_wait_list);
1951                         goto out;
1952                 }
1953         }
1954
1955         transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
1956                               0, DMA_NONE, MSG_SIMPLE_TAG,
1957                               send_ioctx->sense_data);
1958
1959         switch (srp_cmd->opcode) {
1960         case SRP_CMD:
1961                 srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
1962                 break;
1963         case SRP_TSK_MGMT:
1964                 srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
1965                 break;
1966         case SRP_I_LOGOUT:
1967                 printk(KERN_ERR "Not yet implemented: SRP_I_LOGOUT\n");
1968                 break;
1969         case SRP_CRED_RSP:
1970                 pr_debug("received SRP_CRED_RSP\n");
1971                 break;
1972         case SRP_AER_RSP:
1973                 pr_debug("received SRP_AER_RSP\n");
1974                 break;
1975         case SRP_RSP:
1976                 printk(KERN_ERR "Received SRP_RSP\n");
1977                 break;
1978         default:
1979                 printk(KERN_ERR "received IU with unknown opcode 0x%x\n",
1980                        srp_cmd->opcode);
1981                 break;
1982         }
1983
1984         srpt_post_recv(ch->sport->sdev, recv_ioctx);
1985 out:
1986         return;
1987 }
1988
1989 static void srpt_process_rcv_completion(struct ib_cq *cq,
1990                                         struct srpt_rdma_ch *ch,
1991                                         struct ib_wc *wc)
1992 {
1993         struct srpt_device *sdev = ch->sport->sdev;
1994         struct srpt_recv_ioctx *ioctx;
1995         u32 index;
1996
1997         index = idx_from_wr_id(wc->wr_id);
1998         if (wc->status == IB_WC_SUCCESS) {
1999                 int req_lim;
2000
2001                 req_lim = atomic_dec_return(&ch->req_lim);
2002                 if (unlikely(req_lim < 0))
2003                         printk(KERN_ERR "req_lim = %d < 0\n", req_lim);
2004                 ioctx = sdev->ioctx_ring[index];
2005                 srpt_handle_new_iu(ch, ioctx, NULL);
2006         } else {
2007                 printk(KERN_INFO "receiving failed for idx %u with status %d\n",
2008                        index, wc->status);
2009         }
2010 }
2011
2012 /**
2013  * srpt_process_send_completion() - Process an IB send completion.
2014  *
2015  * Note: Although this has not yet been observed during tests, at least in
2016  * theory it is possible that the srpt_get_send_ioctx() call invoked by
2017  * srpt_handle_new_iu() fails. This is possible because the req_lim_delta
2018  * value in each response is set to one, and it is possible that this response
2019  * makes the initiator send a new request before the send completion for that
2020  * response has been processed. This could e.g. happen if the call to
2021  * srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
2022  * if IB retransmission causes generation of the send completion to be
2023  * delayed. Incoming information units for which srpt_get_send_ioctx() fails
2024  * are queued on cmd_wait_list. The code below processes these delayed
2025  * requests one at a time.
2026  */
2027 static void srpt_process_send_completion(struct ib_cq *cq,
2028                                          struct srpt_rdma_ch *ch,
2029                                          struct ib_wc *wc)
2030 {
2031         struct srpt_send_ioctx *send_ioctx;
2032         uint32_t index;
2033         enum srpt_opcode opcode;
2034
2035         index = idx_from_wr_id(wc->wr_id);
2036         opcode = opcode_from_wr_id(wc->wr_id);
2037         send_ioctx = ch->ioctx_ring[index];
2038         if (wc->status == IB_WC_SUCCESS) {
2039                 if (opcode == SRPT_SEND)
2040                         srpt_handle_send_comp(ch, send_ioctx);
2041                 else {
2042                         WARN_ON(opcode != SRPT_RDMA_ABORT &&
2043                                 wc->opcode != IB_WC_RDMA_READ);
2044                         srpt_handle_rdma_comp(ch, send_ioctx, opcode);
2045                 }
2046         } else {
2047                 if (opcode == SRPT_SEND) {
2048                         printk(KERN_INFO "sending response for idx %u failed"
2049                                " with status %d\n", index, wc->status);
2050                         srpt_handle_send_err_comp(ch, wc->wr_id);
2051                 } else if (opcode != SRPT_RDMA_MID) {
2052                         printk(KERN_INFO "RDMA t %d for idx %u failed with"
2053                                 " status %d", opcode, index, wc->status);
2054                         srpt_handle_rdma_err_comp(ch, send_ioctx, opcode);
2055                 }
2056         }
2057
2058         while (unlikely(opcode == SRPT_SEND
2059                         && !list_empty(&ch->cmd_wait_list)
2060                         && srpt_get_ch_state(ch) == CH_LIVE
2061                         && (send_ioctx = srpt_get_send_ioctx(ch)) != NULL)) {
2062                 struct srpt_recv_ioctx *recv_ioctx;
2063
2064                 recv_ioctx = list_first_entry(&ch->cmd_wait_list,
2065                                               struct srpt_recv_ioctx,
2066                                               wait_list);
2067                 list_del(&recv_ioctx->wait_list);
2068                 srpt_handle_new_iu(ch, recv_ioctx, send_ioctx);
2069         }
2070 }
2071
2072 static void srpt_process_completion(struct ib_cq *cq, struct srpt_rdma_ch *ch)
2073 {
2074         struct ib_wc *const wc = ch->wc;
2075         int i, n;
2076
2077         WARN_ON(cq != ch->cq);
2078
2079         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
2080         while ((n = ib_poll_cq(cq, ARRAY_SIZE(ch->wc), wc)) > 0) {
2081                 for (i = 0; i < n; i++) {
2082                         if (opcode_from_wr_id(wc[i].wr_id) == SRPT_RECV)
2083                                 srpt_process_rcv_completion(cq, ch, &wc[i]);
2084                         else
2085                                 srpt_process_send_completion(cq, ch, &wc[i]);
2086                 }
2087         }
2088 }
2089
2090 /**
2091  * srpt_completion() - IB completion queue callback function.
2092  *
2093  * Notes:
2094  * - It is guaranteed that a completion handler will never be invoked
2095  *   concurrently on two different CPUs for the same completion queue. See also
2096  *   Documentation/infiniband/core_locking.txt and the implementation of
2097  *   handle_edge_irq() in kernel/irq/chip.c.
2098  * - When threaded IRQs are enabled, completion handlers are invoked in thread
2099  *   context instead of interrupt context.
2100  */
2101 static void srpt_completion(struct ib_cq *cq, void *ctx)
2102 {
2103         struct srpt_rdma_ch *ch = ctx;
2104
2105         wake_up_interruptible(&ch->wait_queue);
2106 }
2107
2108 static int srpt_compl_thread(void *arg)
2109 {
2110         struct srpt_rdma_ch *ch;
2111
2112         /* Hibernation / freezing of the SRPT kernel thread is not supported. */
2113         current->flags |= PF_NOFREEZE;
2114
2115         ch = arg;
2116         BUG_ON(!ch);
2117         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) started\n",
2118                ch->sess_name, ch->thread->comm, current->pid);
2119         while (!kthread_should_stop()) {
2120                 wait_event_interruptible(ch->wait_queue,
2121                         (srpt_process_completion(ch->cq, ch),
2122                          kthread_should_stop()));
2123         }
2124         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) stopped\n",
2125                ch->sess_name, ch->thread->comm, current->pid);
2126         return 0;
2127 }
2128
2129 /**
2130  * srpt_create_ch_ib() - Create receive and send completion queues.
2131  */
2132 static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
2133 {
2134         struct ib_qp_init_attr *qp_init;
2135         struct srpt_port *sport = ch->sport;
2136         struct srpt_device *sdev = sport->sdev;
2137         u32 srp_sq_size = sport->port_attrib.srp_sq_size;
2138         int ret;
2139
2140         WARN_ON(ch->rq_size < 1);
2141
2142         ret = -ENOMEM;
2143         qp_init = kzalloc(sizeof *qp_init, GFP_KERNEL);
2144         if (!qp_init)
2145                 goto out;
2146
2147         ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
2148                               ch->rq_size + srp_sq_size, 0);
2149         if (IS_ERR(ch->cq)) {
2150                 ret = PTR_ERR(ch->cq);
2151                 printk(KERN_ERR "failed to create CQ cqe= %d ret= %d\n",
2152                        ch->rq_size + srp_sq_size, ret);
2153                 goto out;
2154         }
2155
2156         qp_init->qp_context = (void *)ch;
2157         qp_init->event_handler
2158                 = (void(*)(struct ib_event *, void*))srpt_qp_event;
2159         qp_init->send_cq = ch->cq;
2160         qp_init->recv_cq = ch->cq;
2161         qp_init->srq = sdev->srq;
2162         qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
2163         qp_init->qp_type = IB_QPT_RC;
2164         qp_init->cap.max_send_wr = srp_sq_size;
2165         qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
2166
2167         ch->qp = ib_create_qp(sdev->pd, qp_init);
2168         if (IS_ERR(ch->qp)) {
2169                 ret = PTR_ERR(ch->qp);
2170                 printk(KERN_ERR "failed to create_qp ret= %d\n", ret);
2171                 goto err_destroy_cq;
2172         }
2173
2174         atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
2175
2176         pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
2177                  __func__, ch->cq->cqe, qp_init->cap.max_send_sge,
2178                  qp_init->cap.max_send_wr, ch->cm_id);
2179
2180         ret = srpt_init_ch_qp(ch, ch->qp);
2181         if (ret)
2182                 goto err_destroy_qp;
2183
2184         init_waitqueue_head(&ch->wait_queue);
2185
2186         pr_debug("creating thread for session %s\n", ch->sess_name);
2187
2188         ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
2189         if (IS_ERR(ch->thread)) {
2190                 printk(KERN_ERR "failed to create kernel thread %ld\n",
2191                        PTR_ERR(ch->thread));
2192                 ch->thread = NULL;
2193                 goto err_destroy_qp;
2194         }
2195
2196 out:
2197         kfree(qp_init);
2198         return ret;
2199
2200 err_destroy_qp:
2201         ib_destroy_qp(ch->qp);
2202 err_destroy_cq:
2203         ib_destroy_cq(ch->cq);
2204         goto out;
2205 }
2206
2207 static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
2208 {
2209         if (ch->thread)
2210                 kthread_stop(ch->thread);
2211
2212         ib_destroy_qp(ch->qp);
2213         ib_destroy_cq(ch->cq);
2214 }
2215
2216 /**
2217  * __srpt_close_ch() - Close an RDMA channel by setting the QP error state.
2218  *
2219  * Reset the QP and make sure all resources associated with the channel will
2220  * be deallocated at an appropriate time.
2221  *
2222  * Note: The caller must hold ch->sport->sdev->spinlock.
2223  */
2224 static void __srpt_close_ch(struct srpt_rdma_ch *ch)
2225 {
2226         struct srpt_device *sdev;
2227         enum rdma_ch_state prev_state;
2228         unsigned long flags;
2229
2230         sdev = ch->sport->sdev;
2231
2232         spin_lock_irqsave(&ch->spinlock, flags);
2233         prev_state = ch->state;
2234         switch (prev_state) {
2235         case CH_CONNECTING:
2236         case CH_LIVE:
2237                 ch->state = CH_DISCONNECTING;
2238                 break;
2239         default:
2240                 break;
2241         }
2242         spin_unlock_irqrestore(&ch->spinlock, flags);
2243
2244         switch (prev_state) {
2245         case CH_CONNECTING:
2246                 ib_send_cm_rej(ch->cm_id, IB_CM_REJ_NO_RESOURCES, NULL, 0,
2247                                NULL, 0);
2248                 /* fall through */
2249         case CH_LIVE:
2250                 if (ib_send_cm_dreq(ch->cm_id, NULL, 0) < 0)
2251                         printk(KERN_ERR "sending CM DREQ failed.\n");
2252                 break;
2253         case CH_DISCONNECTING:
2254                 break;
2255         case CH_DRAINING:
2256         case CH_RELEASING:
2257                 break;
2258         }
2259 }
2260
2261 /**
2262  * srpt_close_ch() - Close an RDMA channel.
2263  */
2264 static void srpt_close_ch(struct srpt_rdma_ch *ch)
2265 {
2266         struct srpt_device *sdev;
2267
2268         sdev = ch->sport->sdev;
2269         spin_lock_irq(&sdev->spinlock);
2270         __srpt_close_ch(ch);
2271         spin_unlock_irq(&sdev->spinlock);
2272 }
2273
2274 /**
2275  * srpt_drain_channel() - Drain a channel by resetting the IB queue pair.
2276  * @cm_id: Pointer to the CM ID of the channel to be drained.
2277  *
2278  * Note: Must be called from inside srpt_cm_handler to avoid a race between
2279  * accessing sdev->spinlock and the call to kfree(sdev) in srpt_remove_one()
2280  * (the caller of srpt_cm_handler holds the cm_id spinlock; srpt_remove_one()
2281  * waits until all target sessions for the associated IB device have been
2282  * unregistered and target session registration involves a call to
2283  * ib_destroy_cm_id(), which locks the cm_id spinlock and hence waits until
2284  * this function has finished).
2285  */
2286 static void srpt_drain_channel(struct ib_cm_id *cm_id)
2287 {
2288         struct srpt_device *sdev;
2289         struct srpt_rdma_ch *ch;
2290         int ret;
2291         bool do_reset = false;
2292
2293         WARN_ON_ONCE(irqs_disabled());
2294
2295         sdev = cm_id->context;
2296         BUG_ON(!sdev);
2297         spin_lock_irq(&sdev->spinlock);
2298         list_for_each_entry(ch, &sdev->rch_list, list) {
2299                 if (ch->cm_id == cm_id) {
2300                         do_reset = srpt_test_and_set_ch_state(ch,
2301                                         CH_CONNECTING, CH_DRAINING) ||
2302                                    srpt_test_and_set_ch_state(ch,
2303                                         CH_LIVE, CH_DRAINING) ||
2304                                    srpt_test_and_set_ch_state(ch,
2305                                         CH_DISCONNECTING, CH_DRAINING);
2306                         break;
2307                 }
2308         }
2309         spin_unlock_irq(&sdev->spinlock);
2310
2311         if (do_reset) {
2312                 ret = srpt_ch_qp_err(ch);
2313                 if (ret < 0)
2314                         printk(KERN_ERR "Setting queue pair in error state"
2315                                " failed: %d\n", ret);
2316         }
2317 }
2318
2319 /**
2320  * srpt_find_channel() - Look up an RDMA channel.
2321  * @cm_id: Pointer to the CM ID of the channel to be looked up.
2322  *
2323  * Return NULL if no matching RDMA channel has been found.
2324  */
2325 static struct srpt_rdma_ch *srpt_find_channel(struct srpt_device *sdev,
2326                                               struct ib_cm_id *cm_id)
2327 {
2328         struct srpt_rdma_ch *ch;
2329         bool found;
2330
2331         WARN_ON_ONCE(irqs_disabled());
2332         BUG_ON(!sdev);
2333
2334         found = false;
2335         spin_lock_irq(&sdev->spinlock);
2336         list_for_each_entry(ch, &sdev->rch_list, list) {
2337                 if (ch->cm_id == cm_id) {
2338                         found = true;
2339                         break;
2340                 }
2341         }
2342         spin_unlock_irq(&sdev->spinlock);
2343
2344         return found ? ch : NULL;
2345 }
2346
2347 /**
2348  * srpt_release_channel() - Release channel resources.
2349  *
2350  * Schedules the actual release because:
2351  * - Calling the ib_destroy_cm_id() call from inside an IB CM callback would
2352  *   trigger a deadlock.
2353  * - It is not safe to call TCM transport_* functions from interrupt context.
2354  */
2355 static void srpt_release_channel(struct srpt_rdma_ch *ch)
2356 {
2357         schedule_work(&ch->release_work);
2358 }
2359
2360 static void srpt_release_channel_work(struct work_struct *w)
2361 {
2362         struct srpt_rdma_ch *ch;
2363         struct srpt_device *sdev;
2364
2365         ch = container_of(w, struct srpt_rdma_ch, release_work);
2366         pr_debug("ch = %p; ch->sess = %p; release_done = %p\n", ch, ch->sess,
2367                  ch->release_done);
2368
2369         sdev = ch->sport->sdev;
2370         BUG_ON(!sdev);
2371
2372         transport_deregister_session_configfs(ch->sess);
2373         transport_deregister_session(ch->sess);
2374         ch->sess = NULL;
2375
2376         srpt_destroy_ch_ib(ch);
2377
2378         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2379                              ch->sport->sdev, ch->rq_size,
2380                              ch->rsp_size, DMA_TO_DEVICE);
2381
2382         spin_lock_irq(&sdev->spinlock);
2383         list_del(&ch->list);
2384         spin_unlock_irq(&sdev->spinlock);
2385
2386         ib_destroy_cm_id(ch->cm_id);
2387
2388         if (ch->release_done)
2389                 complete(ch->release_done);
2390
2391         wake_up(&sdev->ch_releaseQ);
2392
2393         kfree(ch);
2394 }
2395
2396 static struct srpt_node_acl *__srpt_lookup_acl(struct srpt_port *sport,
2397                                                u8 i_port_id[16])
2398 {
2399         struct srpt_node_acl *nacl;
2400
2401         list_for_each_entry(nacl, &sport->port_acl_list, list)
2402                 if (memcmp(nacl->i_port_id, i_port_id,
2403                            sizeof(nacl->i_port_id)) == 0)
2404                         return nacl;
2405
2406         return NULL;
2407 }
2408
2409 static struct srpt_node_acl *srpt_lookup_acl(struct srpt_port *sport,
2410                                              u8 i_port_id[16])
2411 {
2412         struct srpt_node_acl *nacl;
2413
2414         spin_lock_irq(&sport->port_acl_lock);
2415         nacl = __srpt_lookup_acl(sport, i_port_id);
2416         spin_unlock_irq(&sport->port_acl_lock);
2417
2418         return nacl;
2419 }
2420
2421 /**
2422  * srpt_cm_req_recv() - Process the event IB_CM_REQ_RECEIVED.
2423  *
2424  * Ownership of the cm_id is transferred to the target session if this
2425  * functions returns zero. Otherwise the caller remains the owner of cm_id.
2426  */
2427 static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
2428                             struct ib_cm_req_event_param *param,
2429                             void *private_data)
2430 {
2431         struct srpt_device *sdev = cm_id->context;
2432         struct srpt_port *sport = &sdev->port[param->port - 1];
2433         struct srp_login_req *req;
2434         struct srp_login_rsp *rsp;
2435         struct srp_login_rej *rej;
2436         struct ib_cm_rep_param *rep_param;
2437         struct srpt_rdma_ch *ch, *tmp_ch;
2438         struct srpt_node_acl *nacl;
2439         u32 it_iu_len;
2440         int i;
2441         int ret = 0;
2442
2443         WARN_ON_ONCE(irqs_disabled());
2444
2445         if (WARN_ON(!sdev || !private_data))
2446                 return -EINVAL;
2447
2448         req = (struct srp_login_req *)private_data;
2449
2450         it_iu_len = be32_to_cpu(req->req_it_iu_len);
2451
2452         printk(KERN_INFO "Received SRP_LOGIN_REQ with i_port_id 0x%llx:0x%llx,"
2453                " t_port_id 0x%llx:0x%llx and it_iu_len %d on port %d"
2454                " (guid=0x%llx:0x%llx)\n",
2455                be64_to_cpu(*(__be64 *)&req->initiator_port_id[0]),
2456                be64_to_cpu(*(__be64 *)&req->initiator_port_id[8]),
2457                be64_to_cpu(*(__be64 *)&req->target_port_id[0]),
2458                be64_to_cpu(*(__be64 *)&req->target_port_id[8]),
2459                it_iu_len,
2460                param->port,
2461                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[0]),
2462                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[8]));
2463
2464         rsp = kzalloc(sizeof *rsp, GFP_KERNEL);
2465         rej = kzalloc(sizeof *rej, GFP_KERNEL);
2466         rep_param = kzalloc(sizeof *rep_param, GFP_KERNEL);
2467
2468         if (!rsp || !rej || !rep_param) {
2469                 ret = -ENOMEM;
2470                 goto out;
2471         }
2472
2473         if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
2474                 rej->reason = __constant_cpu_to_be32(
2475                                 SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
2476                 ret = -EINVAL;
2477                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because its"
2478                        " length (%d bytes) is out of range (%d .. %d)\n",
2479                        it_iu_len, 64, srp_max_req_size);
2480                 goto reject;
2481         }
2482
2483         if (!sport->enabled) {
2484                 rej->reason = __constant_cpu_to_be32(
2485                              SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2486                 ret = -EINVAL;
2487                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because the target port"
2488                        " has not yet been enabled\n");
2489                 goto reject;
2490         }
2491
2492         if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
2493                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN;
2494
2495                 spin_lock_irq(&sdev->spinlock);
2496
2497                 list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list) {
2498                         if (!memcmp(ch->i_port_id, req->initiator_port_id, 16)
2499                             && !memcmp(ch->t_port_id, req->target_port_id, 16)
2500                             && param->port == ch->sport->port
2501                             && param->listen_id == ch->sport->sdev->cm_id
2502                             && ch->cm_id) {
2503                                 enum rdma_ch_state ch_state;
2504
2505                                 ch_state = srpt_get_ch_state(ch);
2506                                 if (ch_state != CH_CONNECTING
2507                                     && ch_state != CH_LIVE)
2508                                         continue;
2509
2510                                 /* found an existing channel */
2511                                 pr_debug("Found existing channel %s"
2512                                          " cm_id= %p state= %d\n",
2513                                          ch->sess_name, ch->cm_id, ch_state);
2514
2515                                 __srpt_close_ch(ch);
2516
2517                                 rsp->rsp_flags =
2518                                         SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
2519                         }
2520                 }
2521
2522                 spin_unlock_irq(&sdev->spinlock);
2523
2524         } else
2525                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
2526
2527         if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
2528             || *(__be64 *)(req->target_port_id + 8) !=
2529                cpu_to_be64(srpt_service_guid)) {
2530                 rej->reason = __constant_cpu_to_be32(
2531                                 SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
2532                 ret = -ENOMEM;
2533                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because it"
2534                        " has an invalid target port identifier.\n");
2535                 goto reject;
2536         }
2537
2538         ch = kzalloc(sizeof *ch, GFP_KERNEL);
2539         if (!ch) {
2540                 rej->reason = __constant_cpu_to_be32(
2541                                         SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2542                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because no memory.\n");
2543                 ret = -ENOMEM;
2544                 goto reject;
2545         }
2546
2547         INIT_WORK(&ch->release_work, srpt_release_channel_work);
2548         memcpy(ch->i_port_id, req->initiator_port_id, 16);
2549         memcpy(ch->t_port_id, req->target_port_id, 16);
2550         ch->sport = &sdev->port[param->port - 1];
2551         ch->cm_id = cm_id;
2552         /*
2553          * Avoid QUEUE_FULL conditions by limiting the number of buffers used
2554          * for the SRP protocol to the command queue size.
2555          */
2556         ch->rq_size = SRPT_RQ_SIZE;
2557         spin_lock_init(&ch->spinlock);
2558         ch->state = CH_CONNECTING;
2559         INIT_LIST_HEAD(&ch->cmd_wait_list);
2560         ch->rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
2561
2562         ch->ioctx_ring = (struct srpt_send_ioctx **)
2563                 srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2564                                       sizeof(*ch->ioctx_ring[0]),
2565                                       ch->rsp_size, DMA_TO_DEVICE);
2566         if (!ch->ioctx_ring)
2567                 goto free_ch;
2568
2569         INIT_LIST_HEAD(&ch->free_list);
2570         for (i = 0; i < ch->rq_size; i++) {
2571                 ch->ioctx_ring[i]->ch = ch;
2572                 list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
2573         }
2574
2575         ret = srpt_create_ch_ib(ch);
2576         if (ret) {
2577                 rej->reason = __constant_cpu_to_be32(
2578                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2579                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because creating"
2580                        " a new RDMA channel failed.\n");
2581                 goto free_ring;
2582         }
2583
2584         ret = srpt_ch_qp_rtr(ch, ch->qp);
2585         if (ret) {
2586                 rej->reason = __constant_cpu_to_be32(
2587                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2588                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because enabling"
2589                        " RTR failed (error code = %d)\n", ret);
2590                 goto destroy_ib;
2591         }
2592         /*
2593          * Use the initator port identifier as the session name.
2594          */
2595         snprintf(ch->sess_name, sizeof(ch->sess_name), "0x%016llx%016llx",
2596                         be64_to_cpu(*(__be64 *)ch->i_port_id),
2597                         be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
2598
2599         pr_debug("registering session %s\n", ch->sess_name);
2600
2601         nacl = srpt_lookup_acl(sport, ch->i_port_id);
2602         if (!nacl) {
2603                 printk(KERN_INFO "Rejected login because no ACL has been"
2604                        " configured yet for initiator %s.\n", ch->sess_name);
2605                 rej->reason = __constant_cpu_to_be32(
2606                                 SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
2607                 goto destroy_ib;
2608         }
2609
2610         ch->sess = transport_init_session();
2611         if (IS_ERR(ch->sess)) {
2612                 rej->reason = __constant_cpu_to_be32(
2613                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2614                 pr_debug("Failed to create session\n");
2615                 goto deregister_session;
2616         }
2617         ch->sess->se_node_acl = &nacl->nacl;
2618         transport_register_session(&sport->port_tpg_1, &nacl->nacl, ch->sess, ch);
2619
2620         pr_debug("Establish connection sess=%p name=%s cm_id=%p\n", ch->sess,
2621                  ch->sess_name, ch->cm_id);
2622
2623         /* create srp_login_response */
2624         rsp->opcode = SRP_LOGIN_RSP;
2625         rsp->tag = req->tag;
2626         rsp->max_it_iu_len = req->req_it_iu_len;
2627         rsp->max_ti_iu_len = req->req_it_iu_len;
2628         ch->max_ti_iu_len = it_iu_len;
2629         rsp->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2630                                               | SRP_BUF_FORMAT_INDIRECT);
2631         rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
2632         atomic_set(&ch->req_lim, ch->rq_size);
2633         atomic_set(&ch->req_lim_delta, 0);
2634
2635         /* create cm reply */
2636         rep_param->qp_num = ch->qp->qp_num;
2637         rep_param->private_data = (void *)rsp;
2638         rep_param->private_data_len = sizeof *rsp;
2639         rep_param->rnr_retry_count = 7;
2640         rep_param->flow_control = 1;
2641         rep_param->failover_accepted = 0;
2642         rep_param->srq = 1;
2643         rep_param->responder_resources = 4;
2644         rep_param->initiator_depth = 4;
2645
2646         ret = ib_send_cm_rep(cm_id, rep_param);
2647         if (ret) {
2648                 printk(KERN_ERR "sending SRP_LOGIN_REQ response failed"
2649                        " (error code = %d)\n", ret);
2650                 goto release_channel;
2651         }
2652
2653         spin_lock_irq(&sdev->spinlock);
2654         list_add_tail(&ch->list, &sdev->rch_list);
2655         spin_unlock_irq(&sdev->spinlock);
2656
2657         goto out;
2658
2659 release_channel:
2660         srpt_set_ch_state(ch, CH_RELEASING);
2661         transport_deregister_session_configfs(ch->sess);
2662
2663 deregister_session:
2664         transport_deregister_session(ch->sess);
2665         ch->sess = NULL;
2666
2667 destroy_ib:
2668         srpt_destroy_ch_ib(ch);
2669
2670 free_ring:
2671         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2672                              ch->sport->sdev, ch->rq_size,
2673                              ch->rsp_size, DMA_TO_DEVICE);
2674 free_ch:
2675         kfree(ch);
2676
2677 reject:
2678         rej->opcode = SRP_LOGIN_REJ;
2679         rej->tag = req->tag;
2680         rej->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2681                                               | SRP_BUF_FORMAT_INDIRECT);
2682
2683         ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
2684                              (void *)rej, sizeof *rej);
2685
2686 out:
2687         kfree(rep_param);
2688         kfree(rsp);
2689         kfree(rej);
2690
2691         return ret;
2692 }
2693
2694 static void srpt_cm_rej_recv(struct ib_cm_id *cm_id)
2695 {
2696         printk(KERN_INFO "Received IB REJ for cm_id %p.\n", cm_id);
2697         srpt_drain_channel(cm_id);
2698 }
2699
2700 /**
2701  * srpt_cm_rtu_recv() - Process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event.
2702  *
2703  * An IB_CM_RTU_RECEIVED message indicates that the connection is established
2704  * and that the recipient may begin transmitting (RTU = ready to use).
2705  */
2706 static void srpt_cm_rtu_recv(struct ib_cm_id *cm_id)
2707 {
2708         struct srpt_rdma_ch *ch;
2709         int ret;
2710
2711         ch = srpt_find_channel(cm_id->context, cm_id);
2712         BUG_ON(!ch);
2713
2714         if (srpt_test_and_set_ch_state(ch, CH_CONNECTING, CH_LIVE)) {
2715                 struct srpt_recv_ioctx *ioctx, *ioctx_tmp;
2716
2717                 ret = srpt_ch_qp_rts(ch, ch->qp);
2718
2719                 list_for_each_entry_safe(ioctx, ioctx_tmp, &ch->cmd_wait_list,
2720                                          wait_list) {
2721                         list_del(&ioctx->wait_list);
2722                         srpt_handle_new_iu(ch, ioctx, NULL);
2723                 }
2724                 if (ret)
2725                         srpt_close_ch(ch);
2726         }
2727 }
2728
2729 static void srpt_cm_timewait_exit(struct ib_cm_id *cm_id)
2730 {
2731         printk(KERN_INFO "Received IB TimeWait exit for cm_id %p.\n", cm_id);
2732         srpt_drain_channel(cm_id);
2733 }
2734
2735 static void srpt_cm_rep_error(struct ib_cm_id *cm_id)
2736 {
2737         printk(KERN_INFO "Received IB REP error for cm_id %p.\n", cm_id);
2738         srpt_drain_channel(cm_id);
2739 }
2740
2741 /**
2742  * srpt_cm_dreq_recv() - Process reception of a DREQ message.
2743  */
2744 static void srpt_cm_dreq_recv(struct ib_cm_id *cm_id)
2745 {
2746         struct srpt_rdma_ch *ch;
2747         unsigned long flags;
2748         bool send_drep = false;
2749
2750         ch = srpt_find_channel(cm_id->context, cm_id);
2751         BUG_ON(!ch);
2752
2753         pr_debug("cm_id= %p ch->state= %d\n", cm_id, srpt_get_ch_state(ch));
2754
2755         spin_lock_irqsave(&ch->spinlock, flags);
2756         switch (ch->state) {
2757         case CH_CONNECTING:
2758         case CH_LIVE:
2759                 send_drep = true;
2760                 ch->state = CH_DISCONNECTING;
2761                 break;
2762         case CH_DISCONNECTING:
2763         case CH_DRAINING:
2764         case CH_RELEASING:
2765                 WARN(true, "unexpected channel state %d\n", ch->state);
2766                 break;
2767         }
2768         spin_unlock_irqrestore(&ch->spinlock, flags);
2769
2770         if (send_drep) {
2771                 if (ib_send_cm_drep(ch->cm_id, NULL, 0) < 0)
2772                         printk(KERN_ERR "Sending IB DREP failed.\n");
2773                 printk(KERN_INFO "Received DREQ and sent DREP for session %s.\n",
2774                        ch->sess_name);
2775         }
2776 }
2777
2778 /**
2779  * srpt_cm_drep_recv() - Process reception of a DREP message.
2780  */
2781 static void srpt_cm_drep_recv(struct ib_cm_id *cm_id)
2782 {
2783         printk(KERN_INFO "Received InfiniBand DREP message for cm_id %p.\n",
2784                cm_id);
2785         srpt_drain_channel(cm_id);
2786 }
2787
2788 /**
2789  * srpt_cm_handler() - IB connection manager callback function.
2790  *
2791  * A non-zero return value will cause the caller destroy the CM ID.
2792  *
2793  * Note: srpt_cm_handler() must only return a non-zero value when transferring
2794  * ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
2795  * a non-zero value in any other case will trigger a race with the
2796  * ib_destroy_cm_id() call in srpt_release_channel().
2797  */
2798 static int srpt_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
2799 {
2800         int ret;
2801
2802         ret = 0;
2803         switch (event->event) {
2804         case IB_CM_REQ_RECEIVED:
2805                 ret = srpt_cm_req_recv(cm_id, &event->param.req_rcvd,
2806                                        event->private_data);
2807                 break;
2808         case IB_CM_REJ_RECEIVED:
2809                 srpt_cm_rej_recv(cm_id);
2810                 break;
2811         case IB_CM_RTU_RECEIVED:
2812         case IB_CM_USER_ESTABLISHED:
2813                 srpt_cm_rtu_recv(cm_id);
2814                 break;
2815         case IB_CM_DREQ_RECEIVED:
2816                 srpt_cm_dreq_recv(cm_id);
2817                 break;
2818         case IB_CM_DREP_RECEIVED:
2819                 srpt_cm_drep_recv(cm_id);
2820                 break;
2821         case IB_CM_TIMEWAIT_EXIT:
2822                 srpt_cm_timewait_exit(cm_id);
2823                 break;
2824         case IB_CM_REP_ERROR:
2825                 srpt_cm_rep_error(cm_id);
2826                 break;
2827         case IB_CM_DREQ_ERROR:
2828                 printk(KERN_INFO "Received IB DREQ ERROR event.\n");
2829                 break;
2830         case IB_CM_MRA_RECEIVED:
2831                 printk(KERN_INFO "Received IB MRA event\n");
2832                 break;
2833         default:
2834                 printk(KERN_ERR "received unrecognized IB CM event %d\n",
2835                        event->event);
2836                 break;
2837         }
2838
2839         return ret;
2840 }
2841
2842 /**
2843  * srpt_perform_rdmas() - Perform IB RDMA.
2844  *
2845  * Returns zero upon success or a negative number upon failure.
2846  */
2847 static int srpt_perform_rdmas(struct srpt_rdma_ch *ch,
2848                               struct srpt_send_ioctx *ioctx)
2849 {
2850         struct ib_send_wr wr;
2851         struct ib_send_wr *bad_wr;
2852         struct rdma_iu *riu;
2853         int i;
2854         int ret;
2855         int sq_wr_avail;
2856         enum dma_data_direction dir;
2857         const int n_rdma = ioctx->n_rdma;
2858
2859         dir = ioctx->cmd.data_direction;
2860         if (dir == DMA_TO_DEVICE) {
2861                 /* write */
2862                 ret = -ENOMEM;
2863                 sq_wr_avail = atomic_sub_return(n_rdma, &ch->sq_wr_avail);
2864                 if (sq_wr_avail < 0) {
2865                         printk(KERN_WARNING "IB send queue full (needed %d)\n",
2866                                n_rdma);
2867                         goto out;
2868                 }
2869         }
2870
2871         ioctx->rdma_aborted = false;
2872         ret = 0;
2873         riu = ioctx->rdma_ius;
2874         memset(&wr, 0, sizeof wr);
2875
2876         for (i = 0; i < n_rdma; ++i, ++riu) {
2877                 if (dir == DMA_FROM_DEVICE) {
2878                         wr.opcode = IB_WR_RDMA_WRITE;
2879                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2880                                                 SRPT_RDMA_WRITE_LAST :
2881                                                 SRPT_RDMA_MID,
2882                                                 ioctx->ioctx.index);
2883                 } else {
2884                         wr.opcode = IB_WR_RDMA_READ;
2885                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2886                                                 SRPT_RDMA_READ_LAST :
2887                                                 SRPT_RDMA_MID,
2888                                                 ioctx->ioctx.index);
2889                 }
2890                 wr.next = NULL;
2891                 wr.wr.rdma.remote_addr = riu->raddr;
2892                 wr.wr.rdma.rkey = riu->rkey;
2893                 wr.num_sge = riu->sge_cnt;
2894                 wr.sg_list = riu->sge;
2895
2896                 /* only get completion event for the last rdma write */
2897                 if (i == (n_rdma - 1) && dir == DMA_TO_DEVICE)
2898                         wr.send_flags = IB_SEND_SIGNALED;
2899
2900                 ret = ib_post_send(ch->qp, &wr, &bad_wr);
2901                 if (ret)
2902                         break;
2903         }
2904
2905         if (ret)
2906                 printk(KERN_ERR "%s[%d]: ib_post_send() returned %d for %d/%d",
2907                                  __func__, __LINE__, ret, i, n_rdma);
2908         if (ret && i > 0) {
2909                 wr.num_sge = 0;
2910                 wr.wr_id = encode_wr_id(SRPT_RDMA_ABORT, ioctx->ioctx.index);
2911                 wr.send_flags = IB_SEND_SIGNALED;
2912                 while (ch->state == CH_LIVE &&
2913                         ib_post_send(ch->qp, &wr, &bad_wr) != 0) {
2914                         printk(KERN_INFO "Trying to abort failed RDMA transfer [%d]",
2915                                 ioctx->ioctx.index);
2916                         msleep(1000);
2917                 }
2918                 while (ch->state != CH_RELEASING && !ioctx->rdma_aborted) {
2919                         printk(KERN_INFO "Waiting until RDMA abort finished [%d]",
2920                                 ioctx->ioctx.index);
2921                         msleep(1000);
2922                 }
2923         }
2924 out:
2925         if (unlikely(dir == DMA_TO_DEVICE && ret < 0))
2926                 atomic_add(n_rdma, &ch->sq_wr_avail);
2927         return ret;
2928 }
2929
2930 /**
2931  * srpt_xfer_data() - Start data transfer from initiator to target.
2932  */
2933 static int srpt_xfer_data(struct srpt_rdma_ch *ch,
2934                           struct srpt_send_ioctx *ioctx)
2935 {
2936         int ret;
2937
2938         ret = srpt_map_sg_to_ib_sge(ch, ioctx);
2939         if (ret) {
2940                 printk(KERN_ERR "%s[%d] ret=%d\n", __func__, __LINE__, ret);
2941                 goto out;
2942         }
2943
2944         ret = srpt_perform_rdmas(ch, ioctx);
2945         if (ret) {
2946                 if (ret == -EAGAIN || ret == -ENOMEM)
2947                         printk(KERN_INFO "%s[%d] queue full -- ret=%d\n",
2948                                    __func__, __LINE__, ret);
2949                 else
2950                         printk(KERN_ERR "%s[%d] fatal error -- ret=%d\n",
2951                                __func__, __LINE__, ret);
2952                 goto out_unmap;
2953         }
2954
2955 out:
2956         return ret;
2957 out_unmap:
2958         srpt_unmap_sg_to_ib_sge(ch, ioctx);
2959         goto out;
2960 }
2961
2962 static int srpt_write_pending_status(struct se_cmd *se_cmd)
2963 {
2964         struct srpt_send_ioctx *ioctx;
2965
2966         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2967         return srpt_get_cmd_state(ioctx) == SRPT_STATE_NEED_DATA;
2968 }
2969
2970 /*
2971  * srpt_write_pending() - Start data transfer from initiator to target (write).
2972  */
2973 static int srpt_write_pending(struct se_cmd *se_cmd)
2974 {
2975         struct srpt_rdma_ch *ch;
2976         struct srpt_send_ioctx *ioctx;
2977         enum srpt_command_state new_state;
2978         enum rdma_ch_state ch_state;
2979         int ret;
2980
2981         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2982
2983         new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
2984         WARN_ON(new_state == SRPT_STATE_DONE);
2985
2986         ch = ioctx->ch;
2987         BUG_ON(!ch);
2988
2989         ch_state = srpt_get_ch_state(ch);
2990         switch (ch_state) {
2991         case CH_CONNECTING:
2992                 WARN(true, "unexpected channel state %d\n", ch_state);
2993                 ret = -EINVAL;
2994                 goto out;
2995         case CH_LIVE:
2996                 break;
2997         case CH_DISCONNECTING:
2998         case CH_DRAINING:
2999         case CH_RELEASING:
3000                 pr_debug("cmd with tag %lld: channel disconnecting\n",
3001                          ioctx->tag);
3002                 srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
3003                 ret = -EINVAL;
3004                 goto out;
3005         }
3006         ret = srpt_xfer_data(ch, ioctx);
3007
3008 out:
3009         return ret;
3010 }
3011
3012 static u8 tcm_to_srp_tsk_mgmt_status(const int tcm_mgmt_status)
3013 {
3014         switch (tcm_mgmt_status) {
3015         case TMR_FUNCTION_COMPLETE:
3016                 return SRP_TSK_MGMT_SUCCESS;
3017         case TMR_FUNCTION_REJECTED:
3018                 return SRP_TSK_MGMT_FUNC_NOT_SUPP;
3019         }
3020         return SRP_TSK_MGMT_FAILED;
3021 }
3022
3023 /**
3024  * srpt_queue_response() - Transmits the response to a SCSI command.
3025  *
3026  * Callback function called by the TCM core. Must not block since it can be
3027  * invoked on the context of the IB completion handler.
3028  */
3029 static int srpt_queue_response(struct se_cmd *cmd)
3030 {
3031         struct srpt_rdma_ch *ch;
3032         struct srpt_send_ioctx *ioctx;
3033         enum srpt_command_state state;
3034         unsigned long flags;
3035         int ret;
3036         enum dma_data_direction dir;
3037         int resp_len;
3038         u8 srp_tm_status;
3039
3040         ret = 0;
3041
3042         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3043         ch = ioctx->ch;
3044         BUG_ON(!ch);
3045
3046         spin_lock_irqsave(&ioctx->spinlock, flags);
3047         state = ioctx->state;
3048         switch (state) {
3049         case SRPT_STATE_NEW:
3050         case SRPT_STATE_DATA_IN:
3051                 ioctx->state = SRPT_STATE_CMD_RSP_SENT;
3052                 break;
3053         case SRPT_STATE_MGMT:
3054                 ioctx->state = SRPT_STATE_MGMT_RSP_SENT;
3055                 break;
3056         default:
3057                 WARN(true, "ch %p; cmd %d: unexpected command state %d\n",
3058                         ch, ioctx->ioctx.index, ioctx->state);
3059                 break;
3060         }
3061         spin_unlock_irqrestore(&ioctx->spinlock, flags);
3062
3063         if (unlikely(transport_check_aborted_status(&ioctx->cmd, false)
3064                      || WARN_ON_ONCE(state == SRPT_STATE_CMD_RSP_SENT))) {
3065                 atomic_inc(&ch->req_lim_delta);
3066                 srpt_abort_cmd(ioctx);
3067                 goto out;
3068         }
3069
3070         dir = ioctx->cmd.data_direction;
3071
3072         /* For read commands, transfer the data to the initiator. */
3073         if (dir == DMA_FROM_DEVICE && ioctx->cmd.data_length &&
3074             !ioctx->queue_status_only) {
3075                 ret = srpt_xfer_data(ch, ioctx);
3076                 if (ret) {
3077                         printk(KERN_ERR "xfer_data failed for tag %llu\n",
3078                                ioctx->tag);
3079                         goto out;
3080                 }
3081         }
3082
3083         if (state != SRPT_STATE_MGMT)
3084                 resp_len = srpt_build_cmd_rsp(ch, ioctx, ioctx->tag,
3085                                               cmd->scsi_status);
3086         else {
3087                 srp_tm_status
3088                         = tcm_to_srp_tsk_mgmt_status(cmd->se_tmr_req->response);
3089                 resp_len = srpt_build_tskmgmt_rsp(ch, ioctx, srp_tm_status,
3090                                                  ioctx->tag);
3091         }
3092         ret = srpt_post_send(ch, ioctx, resp_len);
3093         if (ret) {
3094                 printk(KERN_ERR "sending cmd response failed for tag %llu\n",
3095                        ioctx->tag);
3096                 srpt_unmap_sg_to_ib_sge(ch, ioctx);
3097                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
3098                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
3099         }
3100
3101 out:
3102         return ret;
3103 }
3104
3105 static int srpt_queue_status(struct se_cmd *cmd)
3106 {
3107         struct srpt_send_ioctx *ioctx;
3108
3109         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3110         BUG_ON(ioctx->sense_data != cmd->sense_buffer);
3111         if (cmd->se_cmd_flags &
3112             (SCF_TRANSPORT_TASK_SENSE | SCF_EMULATED_TASK_SENSE))
3113                 WARN_ON(cmd->scsi_status != SAM_STAT_CHECK_CONDITION);
3114         ioctx->queue_status_only = true;
3115         return srpt_queue_response(cmd);
3116 }
3117
3118 static void srpt_refresh_port_work(struct work_struct *work)
3119 {
3120         struct srpt_port *sport = container_of(work, struct srpt_port, work);
3121
3122         srpt_refresh_port(sport);
3123 }
3124
3125 static int srpt_ch_list_empty(struct srpt_device *sdev)
3126 {
3127         int res;
3128
3129         spin_lock_irq(&sdev->spinlock);
3130         res = list_empty(&sdev->rch_list);
3131         spin_unlock_irq(&sdev->spinlock);
3132
3133         return res;
3134 }
3135
3136 /**
3137  * srpt_release_sdev() - Free the channel resources associated with a target.
3138  */
3139 static int srpt_release_sdev(struct srpt_device *sdev)
3140 {
3141         struct srpt_rdma_ch *ch, *tmp_ch;
3142         int res;
3143
3144         WARN_ON_ONCE(irqs_disabled());
3145
3146         BUG_ON(!sdev);
3147
3148         spin_lock_irq(&sdev->spinlock);
3149         list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list)
3150                 __srpt_close_ch(ch);
3151         spin_unlock_irq(&sdev->spinlock);
3152
3153         res = wait_event_interruptible(sdev->ch_releaseQ,
3154                                        srpt_ch_list_empty(sdev));
3155         if (res)
3156                 printk(KERN_ERR "%s: interrupted.\n", __func__);
3157
3158         return 0;
3159 }
3160
3161 static struct srpt_port *__srpt_lookup_port(const char *name)
3162 {
3163         struct ib_device *dev;
3164         struct srpt_device *sdev;
3165         struct srpt_port *sport;
3166         int i;
3167
3168         list_for_each_entry(sdev, &srpt_dev_list, list) {
3169                 dev = sdev->device;
3170                 if (!dev)
3171                         continue;
3172
3173                 for (i = 0; i < dev->phys_port_cnt; i++) {
3174                         sport = &sdev->port[i];
3175
3176                         if (!strcmp(sport->port_guid, name))
3177                                 return sport;
3178                 }
3179         }
3180
3181         return NULL;
3182 }
3183
3184 static struct srpt_port *srpt_lookup_port(const char *name)
3185 {
3186         struct srpt_port *sport;
3187
3188         spin_lock(&srpt_dev_lock);
3189         sport = __srpt_lookup_port(name);
3190         spin_unlock(&srpt_dev_lock);
3191
3192         return sport;
3193 }
3194
3195 /**
3196  * srpt_add_one() - Infiniband device addition callback function.
3197  */
3198 static void srpt_add_one(struct ib_device *device)
3199 {
3200         struct srpt_device *sdev;
3201         struct srpt_port *sport;
3202         struct ib_srq_init_attr srq_attr;
3203         int i;
3204
3205         pr_debug("device = %p, device->dma_ops = %p\n", device,
3206                  device->dma_ops);
3207
3208         sdev = kzalloc(sizeof *sdev, GFP_KERNEL);
3209         if (!sdev)
3210                 goto err;
3211
3212         sdev->device = device;
3213         INIT_LIST_HEAD(&sdev->rch_list);
3214         init_waitqueue_head(&sdev->ch_releaseQ);
3215         spin_lock_init(&sdev->spinlock);
3216
3217         if (ib_query_device(device, &sdev->dev_attr))
3218                 goto free_dev;
3219
3220         sdev->pd = ib_alloc_pd(device);
3221         if (IS_ERR(sdev->pd))
3222                 goto free_dev;
3223
3224         sdev->mr = ib_get_dma_mr(sdev->pd, IB_ACCESS_LOCAL_WRITE);
3225         if (IS_ERR(sdev->mr))
3226                 goto err_pd;
3227
3228         sdev->srq_size = min(srpt_srq_size, sdev->dev_attr.max_srq_wr);
3229
3230         srq_attr.event_handler = srpt_srq_event;
3231         srq_attr.srq_context = (void *)sdev;
3232         srq_attr.attr.max_wr = sdev->srq_size;
3233         srq_attr.attr.max_sge = 1;
3234         srq_attr.attr.srq_limit = 0;
3235         srq_attr.srq_type = IB_SRQT_BASIC;
3236
3237         sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
3238         if (IS_ERR(sdev->srq))
3239                 goto err_mr;
3240
3241         pr_debug("%s: create SRQ #wr= %d max_allow=%d dev= %s\n",
3242                  __func__, sdev->srq_size, sdev->dev_attr.max_srq_wr,
3243                  device->name);
3244
3245         if (!srpt_service_guid)
3246                 srpt_service_guid = be64_to_cpu(device->node_guid);
3247
3248         sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
3249         if (IS_ERR(sdev->cm_id))
3250                 goto err_srq;
3251
3252         /* print out target login information */
3253         pr_debug("Target login info: id_ext=%016llx,ioc_guid=%016llx,"
3254                  "pkey=ffff,service_id=%016llx\n", srpt_service_guid,
3255                  srpt_service_guid, srpt_service_guid);
3256
3257         /*
3258          * We do not have a consistent service_id (ie. also id_ext of target_id)
3259          * to identify this target. We currently use the guid of the first HCA
3260          * in the system as service_id; therefore, the target_id will change
3261          * if this HCA is gone bad and replaced by different HCA
3262          */
3263         if (ib_cm_listen(sdev->cm_id, cpu_to_be64(srpt_service_guid), 0, NULL))
3264                 goto err_cm;
3265
3266         INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
3267                               srpt_event_handler);
3268         if (ib_register_event_handler(&sdev->event_handler))
3269                 goto err_cm;
3270
3271         sdev->ioctx_ring = (struct srpt_recv_ioctx **)
3272                 srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
3273                                       sizeof(*sdev->ioctx_ring[0]),
3274                                       srp_max_req_size, DMA_FROM_DEVICE);
3275         if (!sdev->ioctx_ring)
3276                 goto err_event;
3277
3278         for (i = 0; i < sdev->srq_size; ++i)
3279                 srpt_post_recv(sdev, sdev->ioctx_ring[i]);
3280
3281         WARN_ON(sdev->device->phys_port_cnt > ARRAY_SIZE(sdev->port));
3282
3283         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
3284                 sport = &sdev->port[i - 1];
3285                 sport->sdev = sdev;
3286                 sport->port = i;
3287                 sport->port_attrib.srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
3288                 sport->port_attrib.srp_max_rsp_size = DEFAULT_MAX_RSP_SIZE;
3289                 sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
3290                 INIT_WORK(&sport->work, srpt_refresh_port_work);
3291                 INIT_LIST_HEAD(&sport->port_acl_list);
3292                 spin_lock_init(&sport->port_acl_lock);
3293
3294                 if (srpt_refresh_port(sport)) {
3295                         printk(KERN_ERR "MAD registration failed for %s-%d.\n",
3296                                srpt_sdev_name(sdev), i);
3297                         goto err_ring;
3298                 }
3299                 snprintf(sport->port_guid, sizeof(sport->port_guid),
3300                         "0x%016llx%016llx",
3301                         be64_to_cpu(sport->gid.global.subnet_prefix),
3302                         be64_to_cpu(sport->gid.global.interface_id));
3303         }
3304
3305         spin_lock(&srpt_dev_lock);
3306         list_add_tail(&sdev->list, &srpt_dev_list);
3307         spin_unlock(&srpt_dev_lock);
3308
3309 out:
3310         ib_set_client_data(device, &srpt_client, sdev);
3311         pr_debug("added %s.\n", device->name);
3312         return;
3313
3314 err_ring:
3315         srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3316                              sdev->srq_size, srp_max_req_size,
3317                              DMA_FROM_DEVICE);
3318 err_event:
3319         ib_unregister_event_handler(&sdev->event_handler);
3320 err_cm:
3321         ib_destroy_cm_id(sdev->cm_id);
3322 err_srq:
3323         ib_destroy_srq(sdev->srq);
3324 err_mr:
3325         ib_dereg_mr(sdev->mr);
3326 err_pd:
3327         ib_dealloc_pd(sdev->pd);
3328 free_dev:
3329         kfree(sdev);
3330 err:
3331         sdev = NULL;
3332         printk(KERN_INFO "%s(%s) failed.\n", __func__, device->name);
3333         goto out;
3334 }
3335
3336 /**
3337  * srpt_remove_one() - InfiniBand device removal callback function.
3338  */
3339 static void srpt_remove_one(struct ib_device *device)
3340 {
3341         struct srpt_device *sdev;
3342         int i;
3343
3344         sdev = ib_get_client_data(device, &srpt_client);
3345         if (!sdev) {
3346                 printk(KERN_INFO "%s(%s): nothing to do.\n", __func__,
3347                        device->name);
3348                 return;
3349         }
3350
3351         srpt_unregister_mad_agent(sdev);
3352
3353         ib_unregister_event_handler(&sdev->event_handler);
3354
3355         /* Cancel any work queued by the just unregistered IB event handler. */
3356         for (i = 0; i < sdev->device->phys_port_cnt; i++)
3357                 cancel_work_sync(&sdev->port[i].work);
3358
3359         ib_destroy_cm_id(sdev->cm_id);
3360
3361         /*
3362          * Unregistering a target must happen after destroying sdev->cm_id
3363          * such that no new SRP_LOGIN_REQ information units can arrive while
3364          * destroying the target.
3365          */
3366         spin_lock(&srpt_dev_lock);
3367         list_del(&sdev->list);
3368         spin_unlock(&srpt_dev_lock);
3369         srpt_release_sdev(sdev);
3370
3371         ib_destroy_srq(sdev->srq);
3372         ib_dereg_mr(sdev->mr);
3373         ib_dealloc_pd(sdev->pd);
3374
3375         srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3376                              sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
3377         sdev->ioctx_ring = NULL;
3378         kfree(sdev);
3379 }
3380
3381 static struct ib_client srpt_client = {
3382         .name = DRV_NAME,
3383         .add = srpt_add_one,
3384         .remove = srpt_remove_one
3385 };
3386
3387 static int srpt_check_true(struct se_portal_group *se_tpg)
3388 {
3389         return 1;
3390 }
3391
3392 static int srpt_check_false(struct se_portal_group *se_tpg)
3393 {
3394         return 0;
3395 }
3396
3397 static char *srpt_get_fabric_name(void)
3398 {
3399         return "srpt";
3400 }
3401
3402 static u8 srpt_get_fabric_proto_ident(struct se_portal_group *se_tpg)
3403 {
3404         return SCSI_TRANSPORTID_PROTOCOLID_SRP;
3405 }
3406
3407 static char *srpt_get_fabric_wwn(struct se_portal_group *tpg)
3408 {
3409         struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3410
3411         return sport->port_guid;
3412 }
3413
3414 static u16 srpt_get_tag(struct se_portal_group *tpg)
3415 {
3416         return 1;
3417 }
3418
3419 static u32 srpt_get_default_depth(struct se_portal_group *se_tpg)
3420 {
3421         return 1;
3422 }
3423
3424 static u32 srpt_get_pr_transport_id(struct se_portal_group *se_tpg,
3425                                     struct se_node_acl *se_nacl,
3426                                     struct t10_pr_registration *pr_reg,
3427                                     int *format_code, unsigned char *buf)
3428 {
3429         struct srpt_node_acl *nacl;
3430         struct spc_rdma_transport_id *tr_id;
3431
3432         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3433         tr_id = (void *)buf;
3434         tr_id->protocol_identifier = SCSI_TRANSPORTID_PROTOCOLID_SRP;
3435         memcpy(tr_id->i_port_id, nacl->i_port_id, sizeof(tr_id->i_port_id));
3436         return sizeof(*tr_id);
3437 }
3438
3439 static u32 srpt_get_pr_transport_id_len(struct se_portal_group *se_tpg,
3440                                         struct se_node_acl *se_nacl,
3441                                         struct t10_pr_registration *pr_reg,
3442                                         int *format_code)
3443 {
3444         *format_code = 0;
3445         return sizeof(struct spc_rdma_transport_id);
3446 }
3447
3448 static char *srpt_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
3449                                             const char *buf, u32 *out_tid_len,
3450                                             char **port_nexus_ptr)
3451 {
3452         struct spc_rdma_transport_id *tr_id;
3453
3454         *port_nexus_ptr = NULL;
3455         *out_tid_len = sizeof(struct spc_rdma_transport_id);
3456         tr_id = (void *)buf;
3457         return (char *)tr_id->i_port_id;
3458 }
3459
3460 static struct se_node_acl *srpt_alloc_fabric_acl(struct se_portal_group *se_tpg)
3461 {
3462         struct srpt_node_acl *nacl;
3463
3464         nacl = kzalloc(sizeof(struct srpt_node_acl), GFP_KERNEL);
3465         if (!nacl) {
3466                 printk(KERN_ERR "Unable to allocate struct srpt_node_acl\n");
3467                 return NULL;
3468         }
3469
3470         return &nacl->nacl;
3471 }
3472
3473 static void srpt_release_fabric_acl(struct se_portal_group *se_tpg,
3474                                     struct se_node_acl *se_nacl)
3475 {
3476         struct srpt_node_acl *nacl;
3477
3478         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3479         kfree(nacl);
3480 }
3481
3482 static u32 srpt_tpg_get_inst_index(struct se_portal_group *se_tpg)
3483 {
3484         return 1;
3485 }
3486
3487 static void srpt_release_cmd(struct se_cmd *se_cmd)
3488 {
3489 }
3490
3491 /**
3492  * srpt_shutdown_session() - Whether or not a session may be shut down.
3493  */
3494 static int srpt_shutdown_session(struct se_session *se_sess)
3495 {
3496         return true;
3497 }
3498
3499 /**
3500  * srpt_close_session() - Forcibly close a session.
3501  *
3502  * Callback function invoked by the TCM core to clean up sessions associated
3503  * with a node ACL when the user invokes
3504  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3505  */
3506 static void srpt_close_session(struct se_session *se_sess)
3507 {
3508         DECLARE_COMPLETION_ONSTACK(release_done);
3509         struct srpt_rdma_ch *ch;
3510         struct srpt_device *sdev;
3511         int res;
3512
3513         ch = se_sess->fabric_sess_ptr;
3514         WARN_ON(ch->sess != se_sess);
3515
3516         pr_debug("ch %p state %d\n", ch, srpt_get_ch_state(ch));
3517
3518         sdev = ch->sport->sdev;
3519         spin_lock_irq(&sdev->spinlock);
3520         BUG_ON(ch->release_done);
3521         ch->release_done = &release_done;
3522         __srpt_close_ch(ch);
3523         spin_unlock_irq(&sdev->spinlock);
3524
3525         res = wait_for_completion_timeout(&release_done, 60 * HZ);
3526         WARN_ON(res <= 0);
3527 }
3528
3529 /**
3530  * srpt_sess_get_index() - Return the value of scsiAttIntrPortIndex (SCSI-MIB).
3531  *
3532  * A quote from RFC 4455 (SCSI-MIB) about this MIB object:
3533  * This object represents an arbitrary integer used to uniquely identify a
3534  * particular attached remote initiator port to a particular SCSI target port
3535  * within a particular SCSI target device within a particular SCSI instance.
3536  */
3537 static u32 srpt_sess_get_index(struct se_session *se_sess)
3538 {
3539         return 0;
3540 }
3541
3542 static void srpt_set_default_node_attrs(struct se_node_acl *nacl)
3543 {
3544 }
3545
3546 static u32 srpt_get_task_tag(struct se_cmd *se_cmd)
3547 {
3548         struct srpt_send_ioctx *ioctx;
3549
3550         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3551         return ioctx->tag;
3552 }
3553
3554 /* Note: only used from inside debug printk's by the TCM core. */
3555 static int srpt_get_tcm_cmd_state(struct se_cmd *se_cmd)
3556 {
3557         struct srpt_send_ioctx *ioctx;
3558
3559         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3560         return srpt_get_cmd_state(ioctx);
3561 }
3562
3563 static u16 srpt_set_fabric_sense_len(struct se_cmd *cmd, u32 sense_length)
3564 {
3565         return 0;
3566 }
3567
3568 static u16 srpt_get_fabric_sense_len(void)
3569 {
3570         return 0;
3571 }
3572
3573 /**
3574  * srpt_parse_i_port_id() - Parse an initiator port ID.
3575  * @name: ASCII representation of a 128-bit initiator port ID.
3576  * @i_port_id: Binary 128-bit port ID.
3577  */
3578 static int srpt_parse_i_port_id(u8 i_port_id[16], const char *name)
3579 {
3580         const char *p;
3581         unsigned len, count, leading_zero_bytes;
3582         int ret, rc;
3583
3584         p = name;
3585         if (strnicmp(p, "0x", 2) == 0)
3586                 p += 2;
3587         ret = -EINVAL;
3588         len = strlen(p);
3589         if (len % 2)
3590                 goto out;
3591         count = min(len / 2, 16U);
3592         leading_zero_bytes = 16 - count;
3593         memset(i_port_id, 0, leading_zero_bytes);
3594         rc = hex2bin(i_port_id + leading_zero_bytes, p, count);
3595         if (rc < 0)
3596                 pr_debug("hex2bin failed for srpt_parse_i_port_id: %d\n", rc);
3597         ret = 0;
3598 out:
3599         return ret;
3600 }
3601
3602 /*
3603  * configfs callback function invoked for
3604  * mkdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3605  */
3606 static struct se_node_acl *srpt_make_nodeacl(struct se_portal_group *tpg,
3607                                              struct config_group *group,
3608                                              const char *name)
3609 {
3610         struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3611         struct se_node_acl *se_nacl, *se_nacl_new;
3612         struct srpt_node_acl *nacl;
3613         int ret = 0;
3614         u32 nexus_depth = 1;
3615         u8 i_port_id[16];
3616
3617         if (srpt_parse_i_port_id(i_port_id, name) < 0) {
3618                 printk(KERN_ERR "invalid initiator port ID %s\n", name);
3619                 ret = -EINVAL;
3620                 goto err;
3621         }
3622
3623         se_nacl_new = srpt_alloc_fabric_acl(tpg);
3624         if (!se_nacl_new) {
3625                 ret = -ENOMEM;
3626                 goto err;
3627         }
3628         /*
3629          * nacl_new may be released by core_tpg_add_initiator_node_acl()
3630          * when converting a node ACL from demo mode to explict
3631          */
3632         se_nacl = core_tpg_add_initiator_node_acl(tpg, se_nacl_new, name,
3633                                                   nexus_depth);
3634         if (IS_ERR(se_nacl)) {
3635                 ret = PTR_ERR(se_nacl);
3636                 goto err;
3637         }
3638         /* Locate our struct srpt_node_acl and set sdev and i_port_id. */
3639         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3640         memcpy(&nacl->i_port_id[0], &i_port_id[0], 16);
3641         nacl->sport = sport;
3642
3643         spin_lock_irq(&sport->port_acl_lock);
3644         list_add_tail(&nacl->list, &sport->port_acl_list);
3645         spin_unlock_irq(&sport->port_acl_lock);
3646
3647         return se_nacl;
3648 err:
3649         return ERR_PTR(ret);
3650 }
3651
3652 /*
3653  * configfs callback function invoked for
3654  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3655  */
3656 static void srpt_drop_nodeacl(struct se_node_acl *se_nacl)
3657 {
3658         struct srpt_node_acl *nacl;
3659         struct srpt_device *sdev;
3660         struct srpt_port *sport;
3661
3662         nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3663         sport = nacl->sport;
3664         sdev = sport->sdev;
3665         spin_lock_irq(&sport->port_acl_lock);
3666         list_del(&nacl->list);
3667         spin_unlock_irq(&sport->port_acl_lock);
3668         core_tpg_del_initiator_node_acl(&sport->port_tpg_1, se_nacl, 1);
3669         srpt_release_fabric_acl(NULL, se_nacl);
3670 }
3671
3672 static ssize_t srpt_tpg_attrib_show_srp_max_rdma_size(
3673         struct se_portal_group *se_tpg,
3674         char *page)
3675 {
3676         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3677
3678         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rdma_size);
3679 }
3680
3681 static ssize_t srpt_tpg_attrib_store_srp_max_rdma_size(
3682         struct se_portal_group *se_tpg,
3683         const char *page,
3684         size_t count)
3685 {
3686         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3687         unsigned long val;
3688         int ret;
3689
3690         ret = strict_strtoul(page, 0, &val);
3691         if (ret < 0) {
3692                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3693                 return -EINVAL;
3694         }
3695         if (val > MAX_SRPT_RDMA_SIZE) {
3696                 pr_err("val: %lu exceeds MAX_SRPT_RDMA_SIZE: %d\n", val,
3697                         MAX_SRPT_RDMA_SIZE);
3698                 return -EINVAL;
3699         }
3700         if (val < DEFAULT_MAX_RDMA_SIZE) {
3701                 pr_err("val: %lu smaller than DEFAULT_MAX_RDMA_SIZE: %d\n",
3702                         val, DEFAULT_MAX_RDMA_SIZE);
3703                 return -EINVAL;
3704         }
3705         sport->port_attrib.srp_max_rdma_size = val;
3706
3707         return count;
3708 }
3709
3710 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rdma_size, S_IRUGO | S_IWUSR);
3711
3712 static ssize_t srpt_tpg_attrib_show_srp_max_rsp_size(
3713         struct se_portal_group *se_tpg,
3714         char *page)
3715 {
3716         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3717
3718         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rsp_size);
3719 }
3720
3721 static ssize_t srpt_tpg_attrib_store_srp_max_rsp_size(
3722         struct se_portal_group *se_tpg,
3723         const char *page,
3724         size_t count)
3725 {
3726         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3727         unsigned long val;
3728         int ret;
3729
3730         ret = strict_strtoul(page, 0, &val);
3731         if (ret < 0) {
3732                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3733                 return -EINVAL;
3734         }
3735         if (val > MAX_SRPT_RSP_SIZE) {
3736                 pr_err("val: %lu exceeds MAX_SRPT_RSP_SIZE: %d\n", val,
3737                         MAX_SRPT_RSP_SIZE);
3738                 return -EINVAL;
3739         }
3740         if (val < MIN_MAX_RSP_SIZE) {
3741                 pr_err("val: %lu smaller than MIN_MAX_RSP_SIZE: %d\n", val,
3742                         MIN_MAX_RSP_SIZE);
3743                 return -EINVAL;
3744         }
3745         sport->port_attrib.srp_max_rsp_size = val;
3746
3747         return count;
3748 }
3749
3750 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rsp_size, S_IRUGO | S_IWUSR);
3751
3752 static ssize_t srpt_tpg_attrib_show_srp_sq_size(
3753         struct se_portal_group *se_tpg,
3754         char *page)
3755 {
3756         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3757
3758         return sprintf(page, "%u\n", sport->port_attrib.srp_sq_size);
3759 }
3760
3761 static ssize_t srpt_tpg_attrib_store_srp_sq_size(
3762         struct se_portal_group *se_tpg,
3763         const char *page,
3764         size_t count)
3765 {
3766         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3767         unsigned long val;
3768         int ret;
3769
3770         ret = strict_strtoul(page, 0, &val);
3771         if (ret < 0) {
3772                 pr_err("strict_strtoul() failed with ret: %d\n", ret);
3773                 return -EINVAL;
3774         }
3775         if (val > MAX_SRPT_SRQ_SIZE) {
3776                 pr_err("val: %lu exceeds MAX_SRPT_SRQ_SIZE: %d\n", val,
3777                         MAX_SRPT_SRQ_SIZE);
3778                 return -EINVAL;
3779         }
3780         if (val < MIN_SRPT_SRQ_SIZE) {
3781                 pr_err("val: %lu smaller than MIN_SRPT_SRQ_SIZE: %d\n", val,
3782                         MIN_SRPT_SRQ_SIZE);
3783                 return -EINVAL;
3784         }
3785         sport->port_attrib.srp_sq_size = val;
3786
3787         return count;
3788 }
3789
3790 TF_TPG_ATTRIB_ATTR(srpt, srp_sq_size, S_IRUGO | S_IWUSR);
3791
3792 static struct configfs_attribute *srpt_tpg_attrib_attrs[] = {
3793         &srpt_tpg_attrib_srp_max_rdma_size.attr,
3794         &srpt_tpg_attrib_srp_max_rsp_size.attr,
3795         &srpt_tpg_attrib_srp_sq_size.attr,
3796         NULL,
3797 };
3798
3799 static ssize_t srpt_tpg_show_enable(
3800         struct se_portal_group *se_tpg,
3801         char *page)
3802 {
3803         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3804
3805         return snprintf(page, PAGE_SIZE, "%d\n", (sport->enabled) ? 1: 0);
3806 }
3807
3808 static ssize_t srpt_tpg_store_enable(
3809         struct se_portal_group *se_tpg,
3810         const char *page,
3811         size_t count)
3812 {
3813         struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3814         unsigned long tmp;
3815         int ret;
3816
3817         ret = strict_strtoul(page, 0, &tmp);
3818         if (ret < 0) {
3819                 printk(KERN_ERR "Unable to extract srpt_tpg_store_enable\n");
3820                 return -EINVAL;
3821         }
3822
3823         if ((tmp != 0) && (tmp != 1)) {
3824                 printk(KERN_ERR "Illegal value for srpt_tpg_store_enable: %lu\n", tmp);
3825                 return -EINVAL;
3826         }
3827         if (tmp == 1)
3828                 sport->enabled = true;
3829         else
3830                 sport->enabled = false;
3831
3832         return count;
3833 }
3834
3835 TF_TPG_BASE_ATTR(srpt, enable, S_IRUGO | S_IWUSR);
3836
3837 static struct configfs_attribute *srpt_tpg_attrs[] = {
3838         &srpt_tpg_enable.attr,
3839         NULL,
3840 };
3841
3842 /**
3843  * configfs callback invoked for
3844  * mkdir /sys/kernel/config/target/$driver/$port/$tpg
3845  */
3846 static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
3847                                              struct config_group *group,
3848                                              const char *name)
3849 {
3850         struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3851         int res;
3852
3853         /* Initialize sport->port_wwn and sport->port_tpg_1 */
3854         res = core_tpg_register(&srpt_target->tf_ops, &sport->port_wwn,
3855                         &sport->port_tpg_1, sport, TRANSPORT_TPG_TYPE_NORMAL);
3856         if (res)
3857                 return ERR_PTR(res);
3858
3859         return &sport->port_tpg_1;
3860 }
3861
3862 /**
3863  * configfs callback invoked for
3864  * rmdir /sys/kernel/config/target/$driver/$port/$tpg
3865  */
3866 static void srpt_drop_tpg(struct se_portal_group *tpg)
3867 {
3868         struct srpt_port *sport = container_of(tpg,
3869                                 struct srpt_port, port_tpg_1);
3870
3871         sport->enabled = false;
3872         core_tpg_deregister(&sport->port_tpg_1);
3873 }
3874
3875 /**
3876  * configfs callback invoked for
3877  * mkdir /sys/kernel/config/target/$driver/$port
3878  */
3879 static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf,
3880                                       struct config_group *group,
3881                                       const char *name)
3882 {
3883         struct srpt_port *sport;
3884         int ret;
3885
3886         sport = srpt_lookup_port(name);
3887         pr_debug("make_tport(%s)\n", name);
3888         ret = -EINVAL;
3889         if (!sport)
3890                 goto err;
3891
3892         return &sport->port_wwn;
3893
3894 err:
3895         return ERR_PTR(ret);
3896 }
3897
3898 /**
3899  * configfs callback invoked for
3900  * rmdir /sys/kernel/config/target/$driver/$port
3901  */
3902 static void srpt_drop_tport(struct se_wwn *wwn)
3903 {
3904         struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3905
3906         pr_debug("drop_tport(%s\n", config_item_name(&sport->port_wwn.wwn_group.cg_item));
3907 }
3908
3909 static ssize_t srpt_wwn_show_attr_version(struct target_fabric_configfs *tf,
3910                                               char *buf)
3911 {
3912         return scnprintf(buf, PAGE_SIZE, "%s\n", DRV_VERSION);
3913 }
3914
3915 TF_WWN_ATTR_RO(srpt, version);
3916
3917 static struct configfs_attribute *srpt_wwn_attrs[] = {
3918         &srpt_wwn_version.attr,
3919         NULL,
3920 };
3921
3922 static struct target_core_fabric_ops srpt_template = {
3923         .get_fabric_name                = srpt_get_fabric_name,
3924         .get_fabric_proto_ident         = srpt_get_fabric_proto_ident,
3925         .tpg_get_wwn                    = srpt_get_fabric_wwn,
3926         .tpg_get_tag                    = srpt_get_tag,
3927         .tpg_get_default_depth          = srpt_get_default_depth,
3928         .tpg_get_pr_transport_id        = srpt_get_pr_transport_id,
3929         .tpg_get_pr_transport_id_len    = srpt_get_pr_transport_id_len,
3930         .tpg_parse_pr_out_transport_id  = srpt_parse_pr_out_transport_id,
3931         .tpg_check_demo_mode            = srpt_check_false,
3932         .tpg_check_demo_mode_cache      = srpt_check_true,
3933         .tpg_check_demo_mode_write_protect = srpt_check_true,
3934         .tpg_check_prod_mode_write_protect = srpt_check_false,
3935         .tpg_alloc_fabric_acl           = srpt_alloc_fabric_acl,
3936         .tpg_release_fabric_acl         = srpt_release_fabric_acl,
3937         .tpg_get_inst_index             = srpt_tpg_get_inst_index,
3938         .release_cmd                    = srpt_release_cmd,
3939         .check_stop_free                = srpt_check_stop_free,
3940         .shutdown_session               = srpt_shutdown_session,
3941         .close_session                  = srpt_close_session,
3942         .sess_get_index                 = srpt_sess_get_index,
3943         .sess_get_initiator_sid         = NULL,
3944         .write_pending                  = srpt_write_pending,
3945         .write_pending_status           = srpt_write_pending_status,
3946         .set_default_node_attributes    = srpt_set_default_node_attrs,
3947         .get_task_tag                   = srpt_get_task_tag,
3948         .get_cmd_state                  = srpt_get_tcm_cmd_state,
3949         .queue_data_in                  = srpt_queue_response,
3950         .queue_status                   = srpt_queue_status,
3951         .queue_tm_rsp                   = srpt_queue_response,
3952         .get_fabric_sense_len           = srpt_get_fabric_sense_len,
3953         .set_fabric_sense_len           = srpt_set_fabric_sense_len,
3954         /*
3955          * Setup function pointers for generic logic in
3956          * target_core_fabric_configfs.c
3957          */
3958         .fabric_make_wwn                = srpt_make_tport,
3959         .fabric_drop_wwn                = srpt_drop_tport,
3960         .fabric_make_tpg                = srpt_make_tpg,
3961         .fabric_drop_tpg                = srpt_drop_tpg,
3962         .fabric_post_link               = NULL,
3963         .fabric_pre_unlink              = NULL,
3964         .fabric_make_np                 = NULL,
3965         .fabric_drop_np                 = NULL,
3966         .fabric_make_nodeacl            = srpt_make_nodeacl,
3967         .fabric_drop_nodeacl            = srpt_drop_nodeacl,
3968 };
3969
3970 /**
3971  * srpt_init_module() - Kernel module initialization.
3972  *
3973  * Note: Since ib_register_client() registers callback functions, and since at
3974  * least one of these callback functions (srpt_add_one()) calls target core
3975  * functions, this driver must be registered with the target core before
3976  * ib_register_client() is called.
3977  */
3978 static int __init srpt_init_module(void)
3979 {
3980         int ret;
3981
3982         ret = -EINVAL;
3983         if (srp_max_req_size < MIN_MAX_REQ_SIZE) {
3984                 printk(KERN_ERR "invalid value %d for kernel module parameter"
3985                        " srp_max_req_size -- must be at least %d.\n",
3986                        srp_max_req_size, MIN_MAX_REQ_SIZE);
3987                 goto out;
3988         }
3989
3990         if (srpt_srq_size < MIN_SRPT_SRQ_SIZE
3991             || srpt_srq_size > MAX_SRPT_SRQ_SIZE) {
3992                 printk(KERN_ERR "invalid value %d for kernel module parameter"
3993                        " srpt_srq_size -- must be in the range [%d..%d].\n",
3994                        srpt_srq_size, MIN_SRPT_SRQ_SIZE, MAX_SRPT_SRQ_SIZE);
3995                 goto out;
3996         }
3997
3998         srpt_target = target_fabric_configfs_init(THIS_MODULE, "srpt");
3999         if (IS_ERR(srpt_target)) {
4000                 printk(KERN_ERR "couldn't register\n");
4001                 ret = PTR_ERR(srpt_target);
4002                 goto out;
4003         }
4004
4005         srpt_target->tf_ops = srpt_template;
4006
4007         /* Enable SG chaining */
4008         srpt_target->tf_ops.task_sg_chaining = true;
4009
4010         /*
4011          * Set up default attribute lists.
4012          */
4013         srpt_target->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = srpt_wwn_attrs;
4014         srpt_target->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = srpt_tpg_attrs;
4015         srpt_target->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = srpt_tpg_attrib_attrs;
4016         srpt_target->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
4017         srpt_target->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
4018         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
4019         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
4020         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
4021         srpt_target->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
4022
4023         ret = target_fabric_configfs_register(srpt_target);
4024         if (ret < 0) {
4025                 printk(KERN_ERR "couldn't register\n");
4026                 goto out_free_target;
4027         }
4028
4029         ret = ib_register_client(&srpt_client);
4030         if (ret) {
4031                 printk(KERN_ERR "couldn't register IB client\n");
4032                 goto out_unregister_target;
4033         }
4034
4035         return 0;
4036
4037 out_unregister_target:
4038         target_fabric_configfs_deregister(srpt_target);
4039         srpt_target = NULL;
4040 out_free_target:
4041         if (srpt_target)
4042                 target_fabric_configfs_free(srpt_target);
4043 out:
4044         return ret;
4045 }
4046
4047 static void __exit srpt_cleanup_module(void)
4048 {
4049         ib_unregister_client(&srpt_client);
4050         target_fabric_configfs_deregister(srpt_target);
4051         srpt_target = NULL;
4052 }
4053
4054 module_init(srpt_init_module);
4055 module_exit(srpt_cleanup_module);