drivers/infiniband/ulp/srpt/ib

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This source file includes following definitions.
srpt_get_u64_x
srpt_set_ch_state
srpt_event_handler
srpt_srq_event
get_ch_state_name
srpt_qp_event
srpt_set_ioc
srpt_get_class_port_info
srpt_get_iou
srpt_get_ioc
srpt_get_svc_entries
srpt_mgmt_method_get
srpt_mad_send_handler
srpt_mad_recv_handler
srpt_format_guid
srpt_refresh_port
srpt_unregister_mad_agent
srpt_alloc_ioctx
srpt_free_ioctx
srpt_alloc_ioctx_ring
srpt_free_ioctx_ring
srpt_set_cmd_state
srpt_test_and_set_cmd_state
srpt_post_recv
srpt_zerolength_write
srpt_zerolength_write_done
srpt_alloc_rw_ctxs
srpt_free_rw_ctxs
srpt_get_desc_buf
srpt_get_desc_tbl
srpt_init_ch_qp
srpt_ch_qp_rtr
srpt_ch_qp_rts
srpt_ch_qp_err
srpt_get_send_ioctx
srpt_abort_cmd
srpt_rdma_read_done
srpt_build_cmd_rsp
srpt_build_tskmgmt_rsp
srpt_check_stop_free
srpt_handle_cmd
srp_tmr_to_tcm
srpt_handle_tsk_mgmt
srpt_handle_new_iu
srpt_recv_done
srpt_process_wait_list
srpt_send_done
srpt_create_ch_ib
srpt_destroy_ch_ib
srpt_close_ch
srpt_disconnect_ch
srpt_ch_closed
srpt_disconnect_ch_sync
__srpt_close_all_ch
srpt_get_nexus
srpt_set_enabled
srpt_free_ch
srpt_release_channel_work
srpt_cm_req_recv
srpt_ib_cm_req_recv
srpt_rdma_cm_req_recv
srpt_cm_rej_recv
srpt_cm_rtu_recv
srpt_cm_handler
srpt_rdma_cm_handler
srpt_write_pending
tcm_to_srp_tsk_mgmt_status
srpt_queue_response
srpt_queue_data_in
srpt_queue_tm_rsp
srpt_aborted_task
srpt_queue_status
srpt_refresh_port_work
srpt_ch_list_empty
srpt_release_sport
__srpt_lookup_wwn
srpt_lookup_wwn
srpt_free_srq
srpt_alloc_srq
srpt_use_srq
srpt_add_one
srpt_remove_one
srpt_check_true
srpt_check_false
srpt_tpg_to_sport
srpt_get_fabric_wwn
srpt_get_tag
srpt_tpg_get_inst_index
srpt_release_cmd
srpt_close_session
srpt_sess_get_index
srpt_set_default_node_attrs
srpt_get_tcm_cmd_state
srpt_parse_guid
srpt_parse_i_port_id
srpt_init_nodeacl
srpt_tpg_attrib_srp_max_rdma_size_show
srpt_tpg_attrib_srp_max_rdma_size_store
srpt_tpg_attrib_srp_max_rsp_size_show
srpt_tpg_attrib_srp_max_rsp_size_store
srpt_tpg_attrib_srp_sq_size_show
srpt_tpg_attrib_srp_sq_size_store
srpt_tpg_attrib_use_srq_show
srpt_tpg_attrib_use_srq_store
srpt_create_rdma_id
srpt_rdma_cm_port_show
srpt_rdma_cm_port_store
srpt_tpg_enable_show
srpt_tpg_enable_store
srpt_make_tpg
srpt_drop_tpg
srpt_make_tport
srpt_drop_tport
srpt_wwn_version_show
srpt_init_module
srpt_cleanup_module
   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 <linux/inet.h>
  45 #include <rdma/ib_cache.h>
  46 #include <scsi/scsi_proto.h>
  47 #include <scsi/scsi_tcq.h>
  48 #include <target/target_core_base.h>
  49 #include <target/target_core_fabric.h>
  50 #include "ib_srpt.h"
  51 
  52 /* Name of this kernel module. */
  53 #define DRV_NAME                "ib_srpt"
  54 
  55 #define SRPT_ID_STRING  "Linux SRP target"
  56 
  57 #undef pr_fmt
  58 #define pr_fmt(fmt) DRV_NAME " " fmt
  59 
  60 MODULE_AUTHOR("Vu Pham and Bart Van Assche");
  61 MODULE_DESCRIPTION("SCSI RDMA Protocol target driver");
  62 MODULE_LICENSE("Dual BSD/GPL");
  63 
  64 /*
  65  * Global Variables
  66  */
  67 
  68 static u64 srpt_service_guid;
  69 static DEFINE_SPINLOCK(srpt_dev_lock);  /* Protects srpt_dev_list. */
  70 static LIST_HEAD(srpt_dev_list);        /* List of srpt_device structures. */
  71 
  72 static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
  73 module_param(srp_max_req_size, int, 0444);
  74 MODULE_PARM_DESC(srp_max_req_size,
  75                  "Maximum size of SRP request messages in bytes.");
  76 
  77 static int srpt_srq_size = DEFAULT_SRPT_SRQ_SIZE;
  78 module_param(srpt_srq_size, int, 0444);
  79 MODULE_PARM_DESC(srpt_srq_size,
  80                  "Shared receive queue (SRQ) size.");
  81 
  82 static int srpt_get_u64_x(char *buffer, const struct kernel_param *kp)
  83 {
  84         return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
  85 }
  86 module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
  87                   0444);
  88 MODULE_PARM_DESC(srpt_service_guid,
  89                  "Using this value for ioc_guid, id_ext, and cm_listen_id instead of using the node_guid of the first HCA.");
  90 
  91 static struct ib_client srpt_client;
  92 /* Protects both rdma_cm_port and rdma_cm_id. */
  93 static DEFINE_MUTEX(rdma_cm_mutex);
  94 /* Port number RDMA/CM will bind to. */
  95 static u16 rdma_cm_port;
  96 static struct rdma_cm_id *rdma_cm_id;
  97 static void srpt_release_cmd(struct se_cmd *se_cmd);
  98 static void srpt_free_ch(struct kref *kref);
  99 static int srpt_queue_status(struct se_cmd *cmd);
 100 static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc);
 101 static void srpt_send_done(struct ib_cq *cq, struct ib_wc *wc);
 102 static void srpt_process_wait_list(struct srpt_rdma_ch *ch);
 103 
 104 /*
 105  * The only allowed channel state changes are those that change the channel
 106  * state into a state with a higher numerical value. Hence the new > prev test.
 107  */
 108 static bool srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new)
 109 {
 110         unsigned long flags;
 111         enum rdma_ch_state prev;
 112         bool changed = false;
 113 
 114         spin_lock_irqsave(&ch->spinlock, flags);
 115         prev = ch->state;
 116         if (new > prev) {
 117                 ch->state = new;
 118                 changed = true;
 119         }
 120         spin_unlock_irqrestore(&ch->spinlock, flags);
 121 
 122         return changed;
 123 }
 124 
 125 /**
 126  * srpt_event_handler - asynchronous IB event callback function
 127  * @handler: IB event handler registered by ib_register_event_handler().
 128  * @event: Description of the event that occurred.
 129  *
 130  * Callback function called by the InfiniBand core when an asynchronous IB
 131  * event occurs. This callback may occur in interrupt context. See also
 132  * section 11.5.2, Set Asynchronous Event Handler in the InfiniBand
 133  * Architecture Specification.
 134  */
 135 static void srpt_event_handler(struct ib_event_handler *handler,
 136                                struct ib_event *event)
 137 {
 138         struct srpt_device *sdev;
 139         struct srpt_port *sport;
 140         u8 port_num;
 141 
 142         sdev = ib_get_client_data(event->device, &srpt_client);
 143         if (!sdev || sdev->device != event->device)
 144                 return;
 145 
 146         pr_debug("ASYNC event= %d on device= %s\n", event->event,
 147                  dev_name(&sdev->device->dev));
 148 
 149         switch (event->event) {
 150         case IB_EVENT_PORT_ERR:
 151                 port_num = event->element.port_num - 1;
 152                 if (port_num < sdev->device->phys_port_cnt) {
 153                         sport = &sdev->port[port_num];
 154                         sport->lid = 0;
 155                         sport->sm_lid = 0;
 156                 } else {
 157                         WARN(true, "event %d: port_num %d out of range 1..%d\n",
 158                              event->event, port_num + 1,
 159                              sdev->device->phys_port_cnt);
 160                 }
 161                 break;
 162         case IB_EVENT_PORT_ACTIVE:
 163         case IB_EVENT_LID_CHANGE:
 164         case IB_EVENT_PKEY_CHANGE:
 165         case IB_EVENT_SM_CHANGE:
 166         case IB_EVENT_CLIENT_REREGISTER:
 167         case IB_EVENT_GID_CHANGE:
 168                 /* Refresh port data asynchronously. */
 169                 port_num = event->element.port_num - 1;
 170                 if (port_num < sdev->device->phys_port_cnt) {
 171                         sport = &sdev->port[port_num];
 172                         if (!sport->lid && !sport->sm_lid)
 173                                 schedule_work(&sport->work);
 174                 } else {
 175                         WARN(true, "event %d: port_num %d out of range 1..%d\n",
 176                              event->event, port_num + 1,
 177                              sdev->device->phys_port_cnt);
 178                 }
 179                 break;
 180         default:
 181                 pr_err("received unrecognized IB event %d\n", event->event);
 182                 break;
 183         }
 184 }
 185 
 186 /**
 187  * srpt_srq_event - SRQ event callback function
 188  * @event: Description of the event that occurred.
 189  * @ctx: Context pointer specified at SRQ creation time.
 190  */
 191 static void srpt_srq_event(struct ib_event *event, void *ctx)
 192 {
 193         pr_debug("SRQ event %d\n", event->event);
 194 }
 195 
 196 static const char *get_ch_state_name(enum rdma_ch_state s)
 197 {
 198         switch (s) {
 199         case CH_CONNECTING:
 200                 return "connecting";
 201         case CH_LIVE:
 202                 return "live";
 203         case CH_DISCONNECTING:
 204                 return "disconnecting";
 205         case CH_DRAINING:
 206                 return "draining";
 207         case CH_DISCONNECTED:
 208                 return "disconnected";
 209         }
 210         return "???";
 211 }
 212 
 213 /**
 214  * srpt_qp_event - QP event callback function
 215  * @event: Description of the event that occurred.
 216  * @ch: SRPT RDMA channel.
 217  */
 218 static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
 219 {
 220         pr_debug("QP event %d on ch=%p sess_name=%s state=%d\n",
 221                  event->event, ch, ch->sess_name, ch->state);
 222 
 223         switch (event->event) {
 224         case IB_EVENT_COMM_EST:
 225                 if (ch->using_rdma_cm)
 226                         rdma_notify(ch->rdma_cm.cm_id, event->event);
 227                 else
 228                         ib_cm_notify(ch->ib_cm.cm_id, event->event);
 229                 break;
 230         case IB_EVENT_QP_LAST_WQE_REACHED:
 231                 pr_debug("%s-%d, state %s: received Last WQE event.\n",
 232                          ch->sess_name, ch->qp->qp_num,
 233                          get_ch_state_name(ch->state));
 234                 break;
 235         default:
 236                 pr_err("received unrecognized IB QP event %d\n", event->event);
 237                 break;
 238         }
 239 }
 240 
 241 /**
 242  * srpt_set_ioc - initialize a IOUnitInfo structure
 243  * @c_list: controller list.
 244  * @slot: one-based slot number.
 245  * @value: four-bit value.
 246  *
 247  * Copies the lowest four bits of value in element slot of the array of four
 248  * bit elements called c_list (controller list). The index slot is one-based.
 249  */
 250 static void srpt_set_ioc(u8 *c_list, u32 slot, u8 value)
 251 {
 252         u16 id;
 253         u8 tmp;
 254 
 255         id = (slot - 1) / 2;
 256         if (slot & 0x1) {
 257                 tmp = c_list[id] & 0xf;
 258                 c_list[id] = (value << 4) | tmp;
 259         } else {
 260                 tmp = c_list[id] & 0xf0;
 261                 c_list[id] = (value & 0xf) | tmp;
 262         }
 263 }
 264 
 265 /**
 266  * srpt_get_class_port_info - copy ClassPortInfo to a management datagram
 267  * @mad: Datagram that will be sent as response to DM_ATTR_CLASS_PORT_INFO.
 268  *
 269  * See also section 16.3.3.1 ClassPortInfo in the InfiniBand Architecture
 270  * Specification.
 271  */
 272 static void srpt_get_class_port_info(struct ib_dm_mad *mad)
 273 {
 274         struct ib_class_port_info *cif;
 275 
 276         cif = (struct ib_class_port_info *)mad->data;
 277         memset(cif, 0, sizeof(*cif));
 278         cif->base_version = 1;
 279         cif->class_version = 1;
 280 
 281         ib_set_cpi_resp_time(cif, 20);
 282         mad->mad_hdr.status = 0;
 283 }
 284 
 285 /**
 286  * srpt_get_iou - write IOUnitInfo to a management datagram
 287  * @mad: Datagram that will be sent as response to DM_ATTR_IOU_INFO.
 288  *
 289  * See also section 16.3.3.3 IOUnitInfo in the InfiniBand Architecture
 290  * Specification. See also section B.7, table B.6 in the SRP r16a document.
 291  */
 292 static void srpt_get_iou(struct ib_dm_mad *mad)
 293 {
 294         struct ib_dm_iou_info *ioui;
 295         u8 slot;
 296         int i;
 297 
 298         ioui = (struct ib_dm_iou_info *)mad->data;
 299         ioui->change_id = cpu_to_be16(1);
 300         ioui->max_controllers = 16;
 301 
 302         /* set present for slot 1 and empty for the rest */
 303         srpt_set_ioc(ioui->controller_list, 1, 1);
 304         for (i = 1, slot = 2; i < 16; i++, slot++)
 305                 srpt_set_ioc(ioui->controller_list, slot, 0);
 306 
 307         mad->mad_hdr.status = 0;
 308 }
 309 
 310 /**
 311  * srpt_get_ioc - write IOControllerprofile to a management datagram
 312  * @sport: HCA port through which the MAD has been received.
 313  * @slot: Slot number specified in DM_ATTR_IOC_PROFILE query.
 314  * @mad: Datagram that will be sent as response to DM_ATTR_IOC_PROFILE.
 315  *
 316  * See also section 16.3.3.4 IOControllerProfile in the InfiniBand
 317  * Architecture Specification. See also section B.7, table B.7 in the SRP
 318  * r16a document.
 319  */
 320 static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
 321                          struct ib_dm_mad *mad)
 322 {
 323         struct srpt_device *sdev = sport->sdev;
 324         struct ib_dm_ioc_profile *iocp;
 325         int send_queue_depth;
 326 
 327         iocp = (struct ib_dm_ioc_profile *)mad->data;
 328 
 329         if (!slot || slot > 16) {
 330                 mad->mad_hdr.status
 331                         = cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
 332                 return;
 333         }
 334 
 335         if (slot > 2) {
 336                 mad->mad_hdr.status
 337                         = cpu_to_be16(DM_MAD_STATUS_NO_IOC);
 338                 return;
 339         }
 340 
 341         if (sdev->use_srq)
 342                 send_queue_depth = sdev->srq_size;
 343         else
 344                 send_queue_depth = min(MAX_SRPT_RQ_SIZE,
 345                                        sdev->device->attrs.max_qp_wr);
 346 
 347         memset(iocp, 0, sizeof(*iocp));
 348         strcpy(iocp->id_string, SRPT_ID_STRING);
 349         iocp->guid = cpu_to_be64(srpt_service_guid);
 350         iocp->vendor_id = cpu_to_be32(sdev->device->attrs.vendor_id);
 351         iocp->device_id = cpu_to_be32(sdev->device->attrs.vendor_part_id);
 352         iocp->device_version = cpu_to_be16(sdev->device->attrs.hw_ver);
 353         iocp->subsys_vendor_id = cpu_to_be32(sdev->device->attrs.vendor_id);
 354         iocp->subsys_device_id = 0x0;
 355         iocp->io_class = cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
 356         iocp->io_subclass = cpu_to_be16(SRP_IO_SUBCLASS);
 357         iocp->protocol = cpu_to_be16(SRP_PROTOCOL);
 358         iocp->protocol_version = cpu_to_be16(SRP_PROTOCOL_VERSION);
 359         iocp->send_queue_depth = cpu_to_be16(send_queue_depth);
 360         iocp->rdma_read_depth = 4;
 361         iocp->send_size = cpu_to_be32(srp_max_req_size);
 362         iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
 363                                           1U << 24));
 364         iocp->num_svc_entries = 1;
 365         iocp->op_cap_mask = SRP_SEND_TO_IOC | SRP_SEND_FROM_IOC |
 366                 SRP_RDMA_READ_FROM_IOC | SRP_RDMA_WRITE_FROM_IOC;
 367 
 368         mad->mad_hdr.status = 0;
 369 }
 370 
 371 /**
 372  * srpt_get_svc_entries - write ServiceEntries to a management datagram
 373  * @ioc_guid: I/O controller GUID to use in reply.
 374  * @slot: I/O controller number.
 375  * @hi: End of the range of service entries to be specified in the reply.
 376  * @lo: Start of the range of service entries to be specified in the reply..
 377  * @mad: Datagram that will be sent as response to DM_ATTR_SVC_ENTRIES.
 378  *
 379  * See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
 380  * Specification. See also section B.7, table B.8 in the SRP r16a document.
 381  */
 382 static void srpt_get_svc_entries(u64 ioc_guid,
 383                                  u16 slot, u8 hi, u8 lo, struct ib_dm_mad *mad)
 384 {
 385         struct ib_dm_svc_entries *svc_entries;
 386 
 387         WARN_ON(!ioc_guid);
 388 
 389         if (!slot || slot > 16) {
 390                 mad->mad_hdr.status
 391                         = cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
 392                 return;
 393         }
 394 
 395         if (slot > 2 || lo > hi || hi > 1) {
 396                 mad->mad_hdr.status
 397                         = cpu_to_be16(DM_MAD_STATUS_NO_IOC);
 398                 return;
 399         }
 400 
 401         svc_entries = (struct ib_dm_svc_entries *)mad->data;
 402         memset(svc_entries, 0, sizeof(*svc_entries));
 403         svc_entries->service_entries[0].id = cpu_to_be64(ioc_guid);
 404         snprintf(svc_entries->service_entries[0].name,
 405                  sizeof(svc_entries->service_entries[0].name),
 406                  "%s%016llx",
 407                  SRP_SERVICE_NAME_PREFIX,
 408                  ioc_guid);
 409 
 410         mad->mad_hdr.status = 0;
 411 }
 412 
 413 /**
 414  * srpt_mgmt_method_get - process a received management datagram
 415  * @sp:      HCA port through which the MAD has been received.
 416  * @rq_mad:  received MAD.
 417  * @rsp_mad: response MAD.
 418  */
 419 static void srpt_mgmt_method_get(struct srpt_port *sp, struct ib_mad *rq_mad,
 420                                  struct ib_dm_mad *rsp_mad)
 421 {
 422         u16 attr_id;
 423         u32 slot;
 424         u8 hi, lo;
 425 
 426         attr_id = be16_to_cpu(rq_mad->mad_hdr.attr_id);
 427         switch (attr_id) {
 428         case DM_ATTR_CLASS_PORT_INFO:
 429                 srpt_get_class_port_info(rsp_mad);
 430                 break;
 431         case DM_ATTR_IOU_INFO:
 432                 srpt_get_iou(rsp_mad);
 433                 break;
 434         case DM_ATTR_IOC_PROFILE:
 435                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
 436                 srpt_get_ioc(sp, slot, rsp_mad);
 437                 break;
 438         case DM_ATTR_SVC_ENTRIES:
 439                 slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
 440                 hi = (u8) ((slot >> 8) & 0xff);
 441                 lo = (u8) (slot & 0xff);
 442                 slot = (u16) ((slot >> 16) & 0xffff);
 443                 srpt_get_svc_entries(srpt_service_guid,
 444                                      slot, hi, lo, rsp_mad);
 445                 break;
 446         default:
 447                 rsp_mad->mad_hdr.status =
 448                     cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
 449                 break;
 450         }
 451 }
 452 
 453 /**
 454  * srpt_mad_send_handler - MAD send completion callback
 455  * @mad_agent: Return value of ib_register_mad_agent().
 456  * @mad_wc: Work completion reporting that the MAD has been sent.
 457  */
 458 static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
 459                                   struct ib_mad_send_wc *mad_wc)
 460 {
 461         rdma_destroy_ah(mad_wc->send_buf->ah, RDMA_DESTROY_AH_SLEEPABLE);
 462         ib_free_send_mad(mad_wc->send_buf);
 463 }
 464 
 465 /**
 466  * srpt_mad_recv_handler - MAD reception callback function
 467  * @mad_agent: Return value of ib_register_mad_agent().
 468  * @send_buf: Not used.
 469  * @mad_wc: Work completion reporting that a MAD has been received.
 470  */
 471 static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
 472                                   struct ib_mad_send_buf *send_buf,
 473                                   struct ib_mad_recv_wc *mad_wc)
 474 {
 475         struct srpt_port *sport = (struct srpt_port *)mad_agent->context;
 476         struct ib_ah *ah;
 477         struct ib_mad_send_buf *rsp;
 478         struct ib_dm_mad *dm_mad;
 479 
 480         if (!mad_wc || !mad_wc->recv_buf.mad)
 481                 return;
 482 
 483         ah = ib_create_ah_from_wc(mad_agent->qp->pd, mad_wc->wc,
 484                                   mad_wc->recv_buf.grh, mad_agent->port_num);
 485         if (IS_ERR(ah))
 486                 goto err;
 487 
 488         BUILD_BUG_ON(offsetof(struct ib_dm_mad, data) != IB_MGMT_DEVICE_HDR);
 489 
 490         rsp = ib_create_send_mad(mad_agent, mad_wc->wc->src_qp,
 491                                  mad_wc->wc->pkey_index, 0,
 492                                  IB_MGMT_DEVICE_HDR, IB_MGMT_DEVICE_DATA,
 493                                  GFP_KERNEL,
 494                                  IB_MGMT_BASE_VERSION);
 495         if (IS_ERR(rsp))
 496                 goto err_rsp;
 497 
 498         rsp->ah = ah;
 499 
 500         dm_mad = rsp->mad;
 501         memcpy(dm_mad, mad_wc->recv_buf.mad, sizeof(*dm_mad));
 502         dm_mad->mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
 503         dm_mad->mad_hdr.status = 0;
 504 
 505         switch (mad_wc->recv_buf.mad->mad_hdr.method) {
 506         case IB_MGMT_METHOD_GET:
 507                 srpt_mgmt_method_get(sport, mad_wc->recv_buf.mad, dm_mad);
 508                 break;
 509         case IB_MGMT_METHOD_SET:
 510                 dm_mad->mad_hdr.status =
 511                     cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
 512                 break;
 513         default:
 514                 dm_mad->mad_hdr.status =
 515                     cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD);
 516                 break;
 517         }
 518 
 519         if (!ib_post_send_mad(rsp, NULL)) {
 520                 ib_free_recv_mad(mad_wc);
 521                 /* will destroy_ah & free_send_mad in send completion */
 522                 return;
 523         }
 524 
 525         ib_free_send_mad(rsp);
 526 
 527 err_rsp:
 528         rdma_destroy_ah(ah, RDMA_DESTROY_AH_SLEEPABLE);
 529 err:
 530         ib_free_recv_mad(mad_wc);
 531 }
 532 
 533 static int srpt_format_guid(char *buf, unsigned int size, const __be64 *guid)
 534 {
 535         const __be16 *g = (const __be16 *)guid;
 536 
 537         return snprintf(buf, size, "%04x:%04x:%04x:%04x",
 538                         be16_to_cpu(g[0]), be16_to_cpu(g[1]),
 539                         be16_to_cpu(g[2]), be16_to_cpu(g[3]));
 540 }
 541 
 542 /**
 543  * srpt_refresh_port - configure a HCA port
 544  * @sport: SRPT HCA port.
 545  *
 546  * Enable InfiniBand management datagram processing, update the cached sm_lid,
 547  * lid and gid values, and register a callback function for processing MADs
 548  * on the specified port.
 549  *
 550  * Note: It is safe to call this function more than once for the same port.
 551  */
 552 static int srpt_refresh_port(struct srpt_port *sport)
 553 {
 554         struct ib_mad_reg_req reg_req;
 555         struct ib_port_modify port_modify;
 556         struct ib_port_attr port_attr;
 557         int ret;
 558 
 559         memset(&port_modify, 0, sizeof(port_modify));
 560         port_modify.set_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
 561         port_modify.clr_port_cap_mask = 0;
 562 
 563         ret = ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
 564         if (ret)
 565                 goto err_mod_port;
 566 
 567         ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
 568         if (ret)
 569                 goto err_query_port;
 570 
 571         sport->sm_lid = port_attr.sm_lid;
 572         sport->lid = port_attr.lid;
 573 
 574         ret = rdma_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
 575         if (ret)
 576                 goto err_query_port;
 577 
 578         sport->port_guid_wwn.priv = sport;
 579         srpt_format_guid(sport->port_guid, sizeof(sport->port_guid),
 580                          &sport->gid.global.interface_id);
 581         sport->port_gid_wwn.priv = sport;
 582         snprintf(sport->port_gid, sizeof(sport->port_gid),
 583                  "0x%016llx%016llx",
 584                  be64_to_cpu(sport->gid.global.subnet_prefix),
 585                  be64_to_cpu(sport->gid.global.interface_id));
 586 
 587         if (!sport->mad_agent) {
 588                 memset(&reg_req, 0, sizeof(reg_req));
 589                 reg_req.mgmt_class = IB_MGMT_CLASS_DEVICE_MGMT;
 590                 reg_req.mgmt_class_version = IB_MGMT_BASE_VERSION;
 591                 set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
 592                 set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
 593 
 594                 sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
 595                                                          sport->port,
 596                                                          IB_QPT_GSI,
 597                                                          &reg_req, 0,
 598                                                          srpt_mad_send_handler,
 599                                                          srpt_mad_recv_handler,
 600                                                          sport, 0);
 601                 if (IS_ERR(sport->mad_agent)) {
 602                         ret = PTR_ERR(sport->mad_agent);
 603                         sport->mad_agent = NULL;
 604                         goto err_query_port;
 605                 }
 606         }
 607 
 608         return 0;
 609 
 610 err_query_port:
 611 
 612         port_modify.set_port_cap_mask = 0;
 613         port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
 614         ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
 615 
 616 err_mod_port:
 617 
 618         return ret;
 619 }
 620 
 621 /**
 622  * srpt_unregister_mad_agent - unregister MAD callback functions
 623  * @sdev: SRPT HCA pointer.
 624  *
 625  * Note: It is safe to call this function more than once for the same device.
 626  */
 627 static void srpt_unregister_mad_agent(struct srpt_device *sdev)
 628 {
 629         struct ib_port_modify port_modify = {
 630                 .clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP,
 631         };
 632         struct srpt_port *sport;
 633         int i;
 634 
 635         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
 636                 sport = &sdev->port[i - 1];
 637                 WARN_ON(sport->port != i);
 638                 if (ib_modify_port(sdev->device, i, 0, &port_modify) < 0)
 639                         pr_err("disabling MAD processing failed.\n");
 640                 if (sport->mad_agent) {
 641                         ib_unregister_mad_agent(sport->mad_agent);
 642                         sport->mad_agent = NULL;
 643                 }
 644         }
 645 }
 646 
 647 /**
 648  * srpt_alloc_ioctx - allocate a SRPT I/O context structure
 649  * @sdev: SRPT HCA pointer.
 650  * @ioctx_size: I/O context size.
 651  * @buf_cache: I/O buffer cache.
 652  * @dir: DMA data direction.
 653  */
 654 static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev,
 655                                            int ioctx_size,
 656                                            struct kmem_cache *buf_cache,
 657                                            enum dma_data_direction dir)
 658 {
 659         struct srpt_ioctx *ioctx;
 660 
 661         ioctx = kzalloc(ioctx_size, GFP_KERNEL);
 662         if (!ioctx)
 663                 goto err;
 664 
 665         ioctx->buf = kmem_cache_alloc(buf_cache, GFP_KERNEL);
 666         if (!ioctx->buf)
 667                 goto err_free_ioctx;
 668 
 669         ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf,
 670                                        kmem_cache_size(buf_cache), dir);
 671         if (ib_dma_mapping_error(sdev->device, ioctx->dma))
 672                 goto err_free_buf;
 673 
 674         return ioctx;
 675 
 676 err_free_buf:
 677         kmem_cache_free(buf_cache, ioctx->buf);
 678 err_free_ioctx:
 679         kfree(ioctx);
 680 err:
 681         return NULL;
 682 }
 683 
 684 /**
 685  * srpt_free_ioctx - free a SRPT I/O context structure
 686  * @sdev: SRPT HCA pointer.
 687  * @ioctx: I/O context pointer.
 688  * @buf_cache: I/O buffer cache.
 689  * @dir: DMA data direction.
 690  */
 691 static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx,
 692                             struct kmem_cache *buf_cache,
 693                             enum dma_data_direction dir)
 694 {
 695         if (!ioctx)
 696                 return;
 697 
 698         ib_dma_unmap_single(sdev->device, ioctx->dma,
 699                             kmem_cache_size(buf_cache), dir);
 700         kmem_cache_free(buf_cache, ioctx->buf);
 701         kfree(ioctx);
 702 }
 703 
 704 /**
 705  * srpt_alloc_ioctx_ring - allocate a ring of SRPT I/O context structures
 706  * @sdev:       Device to allocate the I/O context ring for.
 707  * @ring_size:  Number of elements in the I/O context ring.
 708  * @ioctx_size: I/O context size.
 709  * @buf_cache:  I/O buffer cache.
 710  * @alignment_offset: Offset in each ring buffer at which the SRP information
 711  *              unit starts.
 712  * @dir:        DMA data direction.
 713  */
 714 static struct srpt_ioctx **srpt_alloc_ioctx_ring(struct srpt_device *sdev,
 715                                 int ring_size, int ioctx_size,
 716                                 struct kmem_cache *buf_cache,
 717                                 int alignment_offset,
 718                                 enum dma_data_direction dir)
 719 {
 720         struct srpt_ioctx **ring;
 721         int i;
 722 
 723         WARN_ON(ioctx_size != sizeof(struct srpt_recv_ioctx) &&
 724                 ioctx_size != sizeof(struct srpt_send_ioctx));
 725 
 726         ring = kvmalloc_array(ring_size, sizeof(ring[0]), GFP_KERNEL);
 727         if (!ring)
 728                 goto out;
 729         for (i = 0; i < ring_size; ++i) {
 730                 ring[i] = srpt_alloc_ioctx(sdev, ioctx_size, buf_cache, dir);
 731                 if (!ring[i])
 732                         goto err;
 733                 ring[i]->index = i;
 734                 ring[i]->offset = alignment_offset;
 735         }
 736         goto out;
 737 
 738 err:
 739         while (--i >= 0)
 740                 srpt_free_ioctx(sdev, ring[i], buf_cache, dir);
 741         kvfree(ring);
 742         ring = NULL;
 743 out:
 744         return ring;
 745 }
 746 
 747 /**
 748  * srpt_free_ioctx_ring - free the ring of SRPT I/O context structures
 749  * @ioctx_ring: I/O context ring to be freed.
 750  * @sdev: SRPT HCA pointer.
 751  * @ring_size: Number of ring elements.
 752  * @buf_cache: I/O buffer cache.
 753  * @dir: DMA data direction.
 754  */
 755 static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
 756                                  struct srpt_device *sdev, int ring_size,
 757                                  struct kmem_cache *buf_cache,
 758                                  enum dma_data_direction dir)
 759 {
 760         int i;
 761 
 762         if (!ioctx_ring)
 763                 return;
 764 
 765         for (i = 0; i < ring_size; ++i)
 766                 srpt_free_ioctx(sdev, ioctx_ring[i], buf_cache, dir);
 767         kvfree(ioctx_ring);
 768 }
 769 
 770 /**
 771  * srpt_set_cmd_state - set the state of a SCSI command
 772  * @ioctx: Send I/O context.
 773  * @new: New I/O context state.
 774  *
 775  * Does not modify the state of aborted commands. Returns the previous command
 776  * state.
 777  */
 778 static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
 779                                                   enum srpt_command_state new)
 780 {
 781         enum srpt_command_state previous;
 782 
 783         previous = ioctx->state;
 784         if (previous != SRPT_STATE_DONE)
 785                 ioctx->state = new;
 786 
 787         return previous;
 788 }
 789 
 790 /**
 791  * srpt_test_and_set_cmd_state - test and set the state of a command
 792  * @ioctx: Send I/O context.
 793  * @old: Current I/O context state.
 794  * @new: New I/O context state.
 795  *
 796  * Returns true if and only if the previous command state was equal to 'old'.
 797  */
 798 static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
 799                                         enum srpt_command_state old,
 800                                         enum srpt_command_state new)
 801 {
 802         enum srpt_command_state previous;
 803 
 804         WARN_ON(!ioctx);
 805         WARN_ON(old == SRPT_STATE_DONE);
 806         WARN_ON(new == SRPT_STATE_NEW);
 807 
 808         previous = ioctx->state;
 809         if (previous == old)
 810                 ioctx->state = new;
 811 
 812         return previous == old;
 813 }
 814 
 815 /**
 816  * srpt_post_recv - post an IB receive request
 817  * @sdev: SRPT HCA pointer.
 818  * @ch: SRPT RDMA channel.
 819  * @ioctx: Receive I/O context pointer.
 820  */
 821 static int srpt_post_recv(struct srpt_device *sdev, struct srpt_rdma_ch *ch,
 822                           struct srpt_recv_ioctx *ioctx)
 823 {
 824         struct ib_sge list;
 825         struct ib_recv_wr wr;
 826 
 827         BUG_ON(!sdev);
 828         list.addr = ioctx->ioctx.dma + ioctx->ioctx.offset;
 829         list.length = srp_max_req_size;
 830         list.lkey = sdev->lkey;
 831 
 832         ioctx->ioctx.cqe.done = srpt_recv_done;
 833         wr.wr_cqe = &ioctx->ioctx.cqe;
 834         wr.next = NULL;
 835         wr.sg_list = &list;
 836         wr.num_sge = 1;
 837 
 838         if (sdev->use_srq)
 839                 return ib_post_srq_recv(sdev->srq, &wr, NULL);
 840         else
 841                 return ib_post_recv(ch->qp, &wr, NULL);
 842 }
 843 
 844 /**
 845  * srpt_zerolength_write - perform a zero-length RDMA write
 846  * @ch: SRPT RDMA channel.
 847  *
 848  * A quote from the InfiniBand specification: C9-88: For an HCA responder
 849  * using Reliable Connection service, for each zero-length RDMA READ or WRITE
 850  * request, the R_Key shall not be validated, even if the request includes
 851  * Immediate data.
 852  */
 853 static int srpt_zerolength_write(struct srpt_rdma_ch *ch)
 854 {
 855         struct ib_rdma_wr wr = {
 856                 .wr = {
 857                         .next           = NULL,
 858                         { .wr_cqe       = &ch->zw_cqe, },
 859                         .opcode         = IB_WR_RDMA_WRITE,
 860                         .send_flags     = IB_SEND_SIGNALED,
 861                 }
 862         };
 863 
 864         pr_debug("%s-%d: queued zerolength write\n", ch->sess_name,
 865                  ch->qp->qp_num);
 866 
 867         return ib_post_send(ch->qp, &wr.wr, NULL);
 868 }
 869 
 870 static void srpt_zerolength_write_done(struct ib_cq *cq, struct ib_wc *wc)
 871 {
 872         struct srpt_rdma_ch *ch = cq->cq_context;
 873 
 874         pr_debug("%s-%d wc->status %d\n", ch->sess_name, ch->qp->qp_num,
 875                  wc->status);
 876 
 877         if (wc->status == IB_WC_SUCCESS) {
 878                 srpt_process_wait_list(ch);
 879         } else {
 880                 if (srpt_set_ch_state(ch, CH_DISCONNECTED))
 881                         schedule_work(&ch->release_work);
 882                 else
 883                         pr_debug("%s-%d: already disconnected.\n",
 884                                  ch->sess_name, ch->qp->qp_num);
 885         }
 886 }
 887 
 888 static int srpt_alloc_rw_ctxs(struct srpt_send_ioctx *ioctx,
 889                 struct srp_direct_buf *db, int nbufs, struct scatterlist **sg,
 890                 unsigned *sg_cnt)
 891 {
 892         enum dma_data_direction dir = target_reverse_dma_direction(&ioctx->cmd);
 893         struct srpt_rdma_ch *ch = ioctx->ch;
 894         struct scatterlist *prev = NULL;
 895         unsigned prev_nents;
 896         int ret, i;
 897 
 898         if (nbufs == 1) {
 899                 ioctx->rw_ctxs = &ioctx->s_rw_ctx;
 900         } else {
 901                 ioctx->rw_ctxs = kmalloc_array(nbufs, sizeof(*ioctx->rw_ctxs),
 902                         GFP_KERNEL);
 903                 if (!ioctx->rw_ctxs)
 904                         return -ENOMEM;
 905         }
 906 
 907         for (i = ioctx->n_rw_ctx; i < nbufs; i++, db++) {
 908                 struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
 909                 u64 remote_addr = be64_to_cpu(db->va);
 910                 u32 size = be32_to_cpu(db->len);
 911                 u32 rkey = be32_to_cpu(db->key);
 912 
 913                 ret = target_alloc_sgl(&ctx->sg, &ctx->nents, size, false,
 914                                 i < nbufs - 1);
 915                 if (ret)
 916                         goto unwind;
 917 
 918                 ret = rdma_rw_ctx_init(&ctx->rw, ch->qp, ch->sport->port,
 919                                 ctx->sg, ctx->nents, 0, remote_addr, rkey, dir);
 920                 if (ret < 0) {
 921                         target_free_sgl(ctx->sg, ctx->nents);
 922                         goto unwind;
 923                 }
 924 
 925                 ioctx->n_rdma += ret;
 926                 ioctx->n_rw_ctx++;
 927 
 928                 if (prev) {
 929                         sg_unmark_end(&prev[prev_nents - 1]);
 930                         sg_chain(prev, prev_nents + 1, ctx->sg);
 931                 } else {
 932                         *sg = ctx->sg;
 933                 }
 934 
 935                 prev = ctx->sg;
 936                 prev_nents = ctx->nents;
 937 
 938                 *sg_cnt += ctx->nents;
 939         }
 940 
 941         return 0;
 942 
 943 unwind:
 944         while (--i >= 0) {
 945                 struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
 946 
 947                 rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
 948                                 ctx->sg, ctx->nents, dir);
 949                 target_free_sgl(ctx->sg, ctx->nents);
 950         }
 951         if (ioctx->rw_ctxs != &ioctx->s_rw_ctx)
 952                 kfree(ioctx->rw_ctxs);
 953         return ret;
 954 }
 955 
 956 static void srpt_free_rw_ctxs(struct srpt_rdma_ch *ch,
 957                                     struct srpt_send_ioctx *ioctx)
 958 {
 959         enum dma_data_direction dir = target_reverse_dma_direction(&ioctx->cmd);
 960         int i;
 961 
 962         for (i = 0; i < ioctx->n_rw_ctx; i++) {
 963                 struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
 964 
 965                 rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
 966                                 ctx->sg, ctx->nents, dir);
 967                 target_free_sgl(ctx->sg, ctx->nents);
 968         }
 969 
 970         if (ioctx->rw_ctxs != &ioctx->s_rw_ctx)
 971                 kfree(ioctx->rw_ctxs);
 972 }
 973 
 974 static inline void *srpt_get_desc_buf(struct srp_cmd *srp_cmd)
 975 {
 976         /*
 977          * The pointer computations below will only be compiled correctly
 978          * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
 979          * whether srp_cmd::add_data has been declared as a byte pointer.
 980          */
 981         BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0) &&
 982                      !__same_type(srp_cmd->add_data[0], (u8)0));
 983 
 984         /*
 985          * According to the SRP spec, the lower two bits of the 'ADDITIONAL
 986          * CDB LENGTH' field are reserved and the size in bytes of this field
 987          * is four times the value specified in bits 3..7. Hence the "& ~3".
 988          */
 989         return srp_cmd->add_data + (srp_cmd->add_cdb_len & ~3);
 990 }
 991 
 992 /**
 993  * srpt_get_desc_tbl - parse the data descriptors of a SRP_CMD request
 994  * @recv_ioctx: I/O context associated with the received command @srp_cmd.
 995  * @ioctx: I/O context that will be used for responding to the initiator.
 996  * @srp_cmd: Pointer to the SRP_CMD request data.
 997  * @dir: Pointer to the variable to which the transfer direction will be
 998  *   written.
 999  * @sg: [out] scatterlist for the parsed SRP_CMD.
1000  * @sg_cnt: [out] length of @sg.
1001  * @data_len: Pointer to the variable to which the total data length of all
1002  *   descriptors in the SRP_CMD request will be written.
1003  * @imm_data_offset: [in] Offset in SRP_CMD requests at which immediate data
1004  *   starts.
1005  *
1006  * This function initializes ioctx->nrbuf and ioctx->r_bufs.
1007  *
1008  * Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
1009  * -ENOMEM when memory allocation fails and zero upon success.
1010  */
1011 static int srpt_get_desc_tbl(struct srpt_recv_ioctx *recv_ioctx,
1012                 struct srpt_send_ioctx *ioctx,
1013                 struct srp_cmd *srp_cmd, enum dma_data_direction *dir,
1014                 struct scatterlist **sg, unsigned int *sg_cnt, u64 *data_len,
1015                 u16 imm_data_offset)
1016 {
1017         BUG_ON(!dir);
1018         BUG_ON(!data_len);
1019 
1020         /*
1021          * The lower four bits of the buffer format field contain the DATA-IN
1022          * buffer descriptor format, and the highest four bits contain the
1023          * DATA-OUT buffer descriptor format.
1024          */
1025         if (srp_cmd->buf_fmt & 0xf)
1026                 /* DATA-IN: transfer data from target to initiator (read). */
1027                 *dir = DMA_FROM_DEVICE;
1028         else if (srp_cmd->buf_fmt >> 4)
1029                 /* DATA-OUT: transfer data from initiator to target (write). */
1030                 *dir = DMA_TO_DEVICE;
1031         else
1032                 *dir = DMA_NONE;
1033 
1034         /* initialize data_direction early as srpt_alloc_rw_ctxs needs it */
1035         ioctx->cmd.data_direction = *dir;
1036 
1037         if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
1038             ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
1039                 struct srp_direct_buf *db = srpt_get_desc_buf(srp_cmd);
1040 
1041                 *data_len = be32_to_cpu(db->len);
1042                 return srpt_alloc_rw_ctxs(ioctx, db, 1, sg, sg_cnt);
1043         } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
1044                    ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
1045                 struct srp_indirect_buf *idb = srpt_get_desc_buf(srp_cmd);
1046                 int nbufs = be32_to_cpu(idb->table_desc.len) /
1047                                 sizeof(struct srp_direct_buf);
1048 
1049                 if (nbufs >
1050                     (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
1051                         pr_err("received unsupported SRP_CMD request type (%u out + %u in != %u / %zu)\n",
1052                                srp_cmd->data_out_desc_cnt,
1053                                srp_cmd->data_in_desc_cnt,
1054                                be32_to_cpu(idb->table_desc.len),
1055                                sizeof(struct srp_direct_buf));
1056                         return -EINVAL;
1057                 }
1058 
1059                 *data_len = be32_to_cpu(idb->len);
1060                 return srpt_alloc_rw_ctxs(ioctx, idb->desc_list, nbufs,
1061                                 sg, sg_cnt);
1062         } else if ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_IMM) {
1063                 struct srp_imm_buf *imm_buf = srpt_get_desc_buf(srp_cmd);
1064                 void *data = (void *)srp_cmd + imm_data_offset;
1065                 uint32_t len = be32_to_cpu(imm_buf->len);
1066                 uint32_t req_size = imm_data_offset + len;
1067 
1068                 if (req_size > srp_max_req_size) {
1069                         pr_err("Immediate data (length %d + %d) exceeds request size %d\n",
1070                                imm_data_offset, len, srp_max_req_size);
1071                         return -EINVAL;
1072                 }
1073                 if (recv_ioctx->byte_len < req_size) {
1074                         pr_err("Received too few data - %d < %d\n",
1075                                recv_ioctx->byte_len, req_size);
1076                         return -EIO;
1077                 }
1078                 /*
1079                  * The immediate data buffer descriptor must occur before the
1080                  * immediate data itself.
1081                  */
1082                 if ((void *)(imm_buf + 1) > (void *)data) {
1083                         pr_err("Received invalid write request\n");
1084                         return -EINVAL;
1085                 }
1086                 *data_len = len;
1087                 ioctx->recv_ioctx = recv_ioctx;
1088                 if ((uintptr_t)data & 511) {
1089                         pr_warn_once("Internal error - the receive buffers are not aligned properly.\n");
1090                         return -EINVAL;
1091                 }
1092                 sg_init_one(&ioctx->imm_sg, data, len);
1093                 *sg = &ioctx->imm_sg;
1094                 *sg_cnt = 1;
1095                 return 0;
1096         } else {
1097                 *data_len = 0;
1098                 return 0;
1099         }
1100 }
1101 
1102 /**
1103  * srpt_init_ch_qp - initialize queue pair attributes
1104  * @ch: SRPT RDMA channel.
1105  * @qp: Queue pair pointer.
1106  *
1107  * Initialized the attributes of queue pair 'qp' by allowing local write,
1108  * remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
1109  */
1110 static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1111 {
1112         struct ib_qp_attr *attr;
1113         int ret;
1114 
1115         WARN_ON_ONCE(ch->using_rdma_cm);
1116 
1117         attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1118         if (!attr)
1119                 return -ENOMEM;
1120 
1121         attr->qp_state = IB_QPS_INIT;
1122         attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE;
1123         attr->port_num = ch->sport->port;
1124 
1125         ret = ib_find_cached_pkey(ch->sport->sdev->device, ch->sport->port,
1126                                   ch->pkey, &attr->pkey_index);
1127         if (ret < 0)
1128                 pr_err("Translating pkey %#x failed (%d) - using index 0\n",
1129                        ch->pkey, ret);
1130 
1131         ret = ib_modify_qp(qp, attr,
1132                            IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
1133                            IB_QP_PKEY_INDEX);
1134 
1135         kfree(attr);
1136         return ret;
1137 }
1138 
1139 /**
1140  * srpt_ch_qp_rtr - change the state of a channel to 'ready to receive' (RTR)
1141  * @ch: channel of the queue pair.
1142  * @qp: queue pair to change the state of.
1143  *
1144  * Returns zero upon success and a negative value upon failure.
1145  *
1146  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1147  * If this structure ever becomes larger, it might be necessary to allocate
1148  * it dynamically instead of on the stack.
1149  */
1150 static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1151 {
1152         struct ib_qp_attr qp_attr;
1153         int attr_mask;
1154         int ret;
1155 
1156         WARN_ON_ONCE(ch->using_rdma_cm);
1157 
1158         qp_attr.qp_state = IB_QPS_RTR;
1159         ret = ib_cm_init_qp_attr(ch->ib_cm.cm_id, &qp_attr, &attr_mask);
1160         if (ret)
1161                 goto out;
1162 
1163         qp_attr.max_dest_rd_atomic = 4;
1164 
1165         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1166 
1167 out:
1168         return ret;
1169 }
1170 
1171 /**
1172  * srpt_ch_qp_rts - change the state of a channel to 'ready to send' (RTS)
1173  * @ch: channel of the queue pair.
1174  * @qp: queue pair to change the state of.
1175  *
1176  * Returns zero upon success and a negative value upon failure.
1177  *
1178  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1179  * If this structure ever becomes larger, it might be necessary to allocate
1180  * it dynamically instead of on the stack.
1181  */
1182 static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1183 {
1184         struct ib_qp_attr qp_attr;
1185         int attr_mask;
1186         int ret;
1187 
1188         qp_attr.qp_state = IB_QPS_RTS;
1189         ret = ib_cm_init_qp_attr(ch->ib_cm.cm_id, &qp_attr, &attr_mask);
1190         if (ret)
1191                 goto out;
1192 
1193         qp_attr.max_rd_atomic = 4;
1194 
1195         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1196 
1197 out:
1198         return ret;
1199 }
1200 
1201 /**
1202  * srpt_ch_qp_err - set the channel queue pair state to 'error'
1203  * @ch: SRPT RDMA channel.
1204  */
1205 static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
1206 {
1207         struct ib_qp_attr qp_attr;
1208 
1209         qp_attr.qp_state = IB_QPS_ERR;
1210         return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
1211 }
1212 
1213 /**
1214  * srpt_get_send_ioctx - obtain an I/O context for sending to the initiator
1215  * @ch: SRPT RDMA channel.
1216  */
1217 static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
1218 {
1219         struct srpt_send_ioctx *ioctx;
1220         int tag, cpu;
1221 
1222         BUG_ON(!ch);
1223 
1224         tag = sbitmap_queue_get(&ch->sess->sess_tag_pool, &cpu);
1225         if (tag < 0)
1226                 return NULL;
1227 
1228         ioctx = ch->ioctx_ring[tag];
1229         BUG_ON(ioctx->ch != ch);
1230         ioctx->state = SRPT_STATE_NEW;
1231         WARN_ON_ONCE(ioctx->recv_ioctx);
1232         ioctx->n_rdma = 0;
1233         ioctx->n_rw_ctx = 0;
1234         ioctx->queue_status_only = false;
1235         /*
1236          * transport_init_se_cmd() does not initialize all fields, so do it
1237          * here.
1238          */
1239         memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
1240         memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
1241         ioctx->cmd.map_tag = tag;
1242         ioctx->cmd.map_cpu = cpu;
1243 
1244         return ioctx;
1245 }
1246 
1247 /**
1248  * srpt_abort_cmd - abort a SCSI command
1249  * @ioctx:   I/O context associated with the SCSI command.
1250  */
1251 static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
1252 {
1253         enum srpt_command_state state;
1254 
1255         BUG_ON(!ioctx);
1256 
1257         /*
1258          * If the command is in a state where the target core is waiting for
1259          * the ib_srpt driver, change the state to the next state.
1260          */
1261 
1262         state = ioctx->state;
1263         switch (state) {
1264         case SRPT_STATE_NEED_DATA:
1265                 ioctx->state = SRPT_STATE_DATA_IN;
1266                 break;
1267         case SRPT_STATE_CMD_RSP_SENT:
1268         case SRPT_STATE_MGMT_RSP_SENT:
1269                 ioctx->state = SRPT_STATE_DONE;
1270                 break;
1271         default:
1272                 WARN_ONCE(true, "%s: unexpected I/O context state %d\n",
1273                           __func__, state);
1274                 break;
1275         }
1276 
1277         pr_debug("Aborting cmd with state %d -> %d and tag %lld\n", state,
1278                  ioctx->state, ioctx->cmd.tag);
1279 
1280         switch (state) {
1281         case SRPT_STATE_NEW:
1282         case SRPT_STATE_DATA_IN:
1283         case SRPT_STATE_MGMT:
1284         case SRPT_STATE_DONE:
1285                 /*
1286                  * Do nothing - defer abort processing until
1287                  * srpt_queue_response() is invoked.
1288                  */
1289                 break;
1290         case SRPT_STATE_NEED_DATA:
1291                 pr_debug("tag %#llx: RDMA read error\n", ioctx->cmd.tag);
1292                 transport_generic_request_failure(&ioctx->cmd,
1293                                         TCM_CHECK_CONDITION_ABORT_CMD);
1294                 break;
1295         case SRPT_STATE_CMD_RSP_SENT:
1296                 /*
1297                  * SRP_RSP sending failed or the SRP_RSP send completion has
1298                  * not been received in time.
1299                  */
1300                 transport_generic_free_cmd(&ioctx->cmd, 0);
1301                 break;
1302         case SRPT_STATE_MGMT_RSP_SENT:
1303                 transport_generic_free_cmd(&ioctx->cmd, 0);
1304                 break;
1305         default:
1306                 WARN(1, "Unexpected command state (%d)", state);
1307                 break;
1308         }
1309 
1310         return state;
1311 }
1312 
1313 /**
1314  * srpt_rdma_read_done - RDMA read completion callback
1315  * @cq: Completion queue.
1316  * @wc: Work completion.
1317  *
1318  * XXX: what is now target_execute_cmd used to be asynchronous, and unmapping
1319  * the data that has been transferred via IB RDMA had to be postponed until the
1320  * check_stop_free() callback.  None of this is necessary anymore and needs to
1321  * be cleaned up.
1322  */
1323 static void srpt_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
1324 {
1325         struct srpt_rdma_ch *ch = cq->cq_context;
1326         struct srpt_send_ioctx *ioctx =
1327                 container_of(wc->wr_cqe, struct srpt_send_ioctx, rdma_cqe);
1328 
1329         WARN_ON(ioctx->n_rdma <= 0);
1330         atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1331         ioctx->n_rdma = 0;
1332 
1333         if (unlikely(wc->status != IB_WC_SUCCESS)) {
1334                 pr_info("RDMA_READ for ioctx 0x%p failed with status %d\n",
1335                         ioctx, wc->status);
1336                 srpt_abort_cmd(ioctx);
1337                 return;
1338         }
1339 
1340         if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
1341                                         SRPT_STATE_DATA_IN))
1342                 target_execute_cmd(&ioctx->cmd);
1343         else
1344                 pr_err("%s[%d]: wrong state = %d\n", __func__,
1345                        __LINE__, ioctx->state);
1346 }
1347 
1348 /**
1349  * srpt_build_cmd_rsp - build a SRP_RSP response
1350  * @ch: RDMA channel through which the request has been received.
1351  * @ioctx: I/O context associated with the SRP_CMD request. The response will
1352  *   be built in the buffer ioctx->buf points at and hence this function will
1353  *   overwrite the request data.
1354  * @tag: tag of the request for which this response is being generated.
1355  * @status: value for the STATUS field of the SRP_RSP information unit.
1356  *
1357  * Returns the size in bytes of the SRP_RSP response.
1358  *
1359  * An SRP_RSP response contains a SCSI status or service response. See also
1360  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1361  * response. See also SPC-2 for more information about sense data.
1362  */
1363 static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
1364                               struct srpt_send_ioctx *ioctx, u64 tag,
1365                               int status)
1366 {
1367         struct se_cmd *cmd = &ioctx->cmd;
1368         struct srp_rsp *srp_rsp;
1369         const u8 *sense_data;
1370         int sense_data_len, max_sense_len;
1371         u32 resid = cmd->residual_count;
1372 
1373         /*
1374          * The lowest bit of all SAM-3 status codes is zero (see also
1375          * paragraph 5.3 in SAM-3).
1376          */
1377         WARN_ON(status & 1);
1378 
1379         srp_rsp = ioctx->ioctx.buf;
1380         BUG_ON(!srp_rsp);
1381 
1382         sense_data = ioctx->sense_data;
1383         sense_data_len = ioctx->cmd.scsi_sense_length;
1384         WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
1385 
1386         memset(srp_rsp, 0, sizeof(*srp_rsp));
1387         srp_rsp->opcode = SRP_RSP;
1388         srp_rsp->req_lim_delta =
1389                 cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1390         srp_rsp->tag = tag;
1391         srp_rsp->status = status;
1392 
1393         if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1394                 if (cmd->data_direction == DMA_TO_DEVICE) {
1395                         /* residual data from an underflow write */
1396                         srp_rsp->flags = SRP_RSP_FLAG_DOUNDER;
1397                         srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
1398                 } else if (cmd->data_direction == DMA_FROM_DEVICE) {
1399                         /* residual data from an underflow read */
1400                         srp_rsp->flags = SRP_RSP_FLAG_DIUNDER;
1401                         srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
1402                 }
1403         } else if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1404                 if (cmd->data_direction == DMA_TO_DEVICE) {
1405                         /* residual data from an overflow write */
1406                         srp_rsp->flags = SRP_RSP_FLAG_DOOVER;
1407                         srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
1408                 } else if (cmd->data_direction == DMA_FROM_DEVICE) {
1409                         /* residual data from an overflow read */
1410                         srp_rsp->flags = SRP_RSP_FLAG_DIOVER;
1411                         srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
1412                 }
1413         }
1414 
1415         if (sense_data_len) {
1416                 BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
1417                 max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
1418                 if (sense_data_len > max_sense_len) {
1419                         pr_warn("truncated sense data from %d to %d bytes\n",
1420                                 sense_data_len, max_sense_len);
1421                         sense_data_len = max_sense_len;
1422                 }
1423 
1424                 srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
1425                 srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
1426                 memcpy(srp_rsp + 1, sense_data, sense_data_len);
1427         }
1428 
1429         return sizeof(*srp_rsp) + sense_data_len;
1430 }
1431 
1432 /**
1433  * srpt_build_tskmgmt_rsp - build a task management response
1434  * @ch:       RDMA channel through which the request has been received.
1435  * @ioctx:    I/O context in which the SRP_RSP response will be built.
1436  * @rsp_code: RSP_CODE that will be stored in the response.
1437  * @tag:      Tag of the request for which this response is being generated.
1438  *
1439  * Returns the size in bytes of the SRP_RSP response.
1440  *
1441  * An SRP_RSP response contains a SCSI status or service response. See also
1442  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1443  * response.
1444  */
1445 static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
1446                                   struct srpt_send_ioctx *ioctx,
1447                                   u8 rsp_code, u64 tag)
1448 {
1449         struct srp_rsp *srp_rsp;
1450         int resp_data_len;
1451         int resp_len;
1452 
1453         resp_data_len = 4;
1454         resp_len = sizeof(*srp_rsp) + resp_data_len;
1455 
1456         srp_rsp = ioctx->ioctx.buf;
1457         BUG_ON(!srp_rsp);
1458         memset(srp_rsp, 0, sizeof(*srp_rsp));
1459 
1460         srp_rsp->opcode = SRP_RSP;
1461         srp_rsp->req_lim_delta =
1462                 cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1463         srp_rsp->tag = tag;
1464 
1465         srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
1466         srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
1467         srp_rsp->data[3] = rsp_code;
1468 
1469         return resp_len;
1470 }
1471 
1472 static int srpt_check_stop_free(struct se_cmd *cmd)
1473 {
1474         struct srpt_send_ioctx *ioctx = container_of(cmd,
1475                                 struct srpt_send_ioctx, cmd);
1476 
1477         return target_put_sess_cmd(&ioctx->cmd);
1478 }
1479 
1480 /**
1481  * srpt_handle_cmd - process a SRP_CMD information unit
1482  * @ch: SRPT RDMA channel.
1483  * @recv_ioctx: Receive I/O context.
1484  * @send_ioctx: Send I/O context.
1485  */
1486 static void srpt_handle_cmd(struct srpt_rdma_ch *ch,
1487                             struct srpt_recv_ioctx *recv_ioctx,
1488                             struct srpt_send_ioctx *send_ioctx)
1489 {
1490         struct se_cmd *cmd;
1491         struct srp_cmd *srp_cmd;
1492         struct scatterlist *sg = NULL;
1493         unsigned sg_cnt = 0;
1494         u64 data_len;
1495         enum dma_data_direction dir;
1496         int rc;
1497 
1498         BUG_ON(!send_ioctx);
1499 
1500         srp_cmd = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
1501         cmd = &send_ioctx->cmd;
1502         cmd->tag = srp_cmd->tag;
1503 
1504         switch (srp_cmd->task_attr) {
1505         case SRP_CMD_SIMPLE_Q:
1506                 cmd->sam_task_attr = TCM_SIMPLE_TAG;
1507                 break;
1508         case SRP_CMD_ORDERED_Q:
1509         default:
1510                 cmd->sam_task_attr = TCM_ORDERED_TAG;
1511                 break;
1512         case SRP_CMD_HEAD_OF_Q:
1513                 cmd->sam_task_attr = TCM_HEAD_TAG;
1514                 break;
1515         case SRP_CMD_ACA:
1516                 cmd->sam_task_attr = TCM_ACA_TAG;
1517                 break;
1518         }
1519 
1520         rc = srpt_get_desc_tbl(recv_ioctx, send_ioctx, srp_cmd, &dir,
1521                                &sg, &sg_cnt, &data_len, ch->imm_data_offset);
1522         if (rc) {
1523                 if (rc != -EAGAIN) {
1524                         pr_err("0x%llx: parsing SRP descriptor table failed.\n",
1525                                srp_cmd->tag);
1526                 }
1527                 goto busy;
1528         }
1529 
1530         rc = target_submit_cmd_map_sgls(cmd, ch->sess, srp_cmd->cdb,
1531                                &send_ioctx->sense_data[0],
1532                                scsilun_to_int(&srp_cmd->lun), data_len,
1533                                TCM_SIMPLE_TAG, dir, TARGET_SCF_ACK_KREF,
1534                                sg, sg_cnt, NULL, 0, NULL, 0);
1535         if (rc != 0) {
1536                 pr_debug("target_submit_cmd() returned %d for tag %#llx\n", rc,
1537                          srp_cmd->tag);
1538                 goto busy;
1539         }
1540         return;
1541 
1542 busy:
1543         target_send_busy(cmd);
1544 }
1545 
1546 static int srp_tmr_to_tcm(int fn)
1547 {
1548         switch (fn) {
1549         case SRP_TSK_ABORT_TASK:
1550                 return TMR_ABORT_TASK;
1551         case SRP_TSK_ABORT_TASK_SET:
1552                 return TMR_ABORT_TASK_SET;
1553         case SRP_TSK_CLEAR_TASK_SET:
1554                 return TMR_CLEAR_TASK_SET;
1555         case SRP_TSK_LUN_RESET:
1556                 return TMR_LUN_RESET;
1557         case SRP_TSK_CLEAR_ACA:
1558                 return TMR_CLEAR_ACA;
1559         default:
1560                 return -1;
1561         }
1562 }
1563 
1564 /**
1565  * srpt_handle_tsk_mgmt - process a SRP_TSK_MGMT information unit
1566  * @ch: SRPT RDMA channel.
1567  * @recv_ioctx: Receive I/O context.
1568  * @send_ioctx: Send I/O context.
1569  *
1570  * Returns 0 if and only if the request will be processed by the target core.
1571  *
1572  * For more information about SRP_TSK_MGMT information units, see also section
1573  * 6.7 in the SRP r16a document.
1574  */
1575 static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
1576                                  struct srpt_recv_ioctx *recv_ioctx,
1577                                  struct srpt_send_ioctx *send_ioctx)
1578 {
1579         struct srp_tsk_mgmt *srp_tsk;
1580         struct se_cmd *cmd;
1581         struct se_session *sess = ch->sess;
1582         int tcm_tmr;
1583         int rc;
1584 
1585         BUG_ON(!send_ioctx);
1586 
1587         srp_tsk = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
1588         cmd = &send_ioctx->cmd;
1589 
1590         pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld ch %p sess %p\n",
1591                  srp_tsk->tsk_mgmt_func, srp_tsk->task_tag, srp_tsk->tag, ch,
1592                  ch->sess);
1593 
1594         srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
1595         send_ioctx->cmd.tag = srp_tsk->tag;
1596         tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
1597         rc = target_submit_tmr(&send_ioctx->cmd, sess, NULL,
1598                                scsilun_to_int(&srp_tsk->lun), srp_tsk, tcm_tmr,
1599                                GFP_KERNEL, srp_tsk->task_tag,
1600                                TARGET_SCF_ACK_KREF);
1601         if (rc != 0) {
1602                 send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
1603                 cmd->se_tfo->queue_tm_rsp(cmd);
1604         }
1605         return;
1606 }
1607 
1608 /**
1609  * srpt_handle_new_iu - process a newly received information unit
1610  * @ch:    RDMA channel through which the information unit has been received.
1611  * @recv_ioctx: Receive I/O context associated with the information unit.
1612  */
1613 static bool
1614 srpt_handle_new_iu(struct srpt_rdma_ch *ch, struct srpt_recv_ioctx *recv_ioctx)
1615 {
1616         struct srpt_send_ioctx *send_ioctx = NULL;
1617         struct srp_cmd *srp_cmd;
1618         bool res = false;
1619         u8 opcode;
1620 
1621         BUG_ON(!ch);
1622         BUG_ON(!recv_ioctx);
1623 
1624         if (unlikely(ch->state == CH_CONNECTING))
1625                 goto push;
1626 
1627         ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
1628                                    recv_ioctx->ioctx.dma,
1629                                    recv_ioctx->ioctx.offset + srp_max_req_size,
1630                                    DMA_FROM_DEVICE);
1631 
1632         srp_cmd = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
1633         opcode = srp_cmd->opcode;
1634         if (opcode == SRP_CMD || opcode == SRP_TSK_MGMT) {
1635                 send_ioctx = srpt_get_send_ioctx(ch);
1636                 if (unlikely(!send_ioctx))
1637                         goto push;
1638         }
1639 
1640         if (!list_empty(&recv_ioctx->wait_list)) {
1641                 WARN_ON_ONCE(!ch->processing_wait_list);
1642                 list_del_init(&recv_ioctx->wait_list);
1643         }
1644 
1645         switch (opcode) {
1646         case SRP_CMD:
1647                 srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
1648                 break;
1649         case SRP_TSK_MGMT:
1650                 srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
1651                 break;
1652         case SRP_I_LOGOUT:
1653                 pr_err("Not yet implemented: SRP_I_LOGOUT\n");
1654                 break;
1655         case SRP_CRED_RSP:
1656                 pr_debug("received SRP_CRED_RSP\n");
1657                 break;
1658         case SRP_AER_RSP:
1659                 pr_debug("received SRP_AER_RSP\n");
1660                 break;
1661         case SRP_RSP:
1662                 pr_err("Received SRP_RSP\n");
1663                 break;
1664         default:
1665                 pr_err("received IU with unknown opcode 0x%x\n", opcode);
1666                 break;
1667         }
1668 
1669         if (!send_ioctx || !send_ioctx->recv_ioctx)
1670                 srpt_post_recv(ch->sport->sdev, ch, recv_ioctx);
1671         res = true;
1672 
1673 out:
1674         return res;
1675 
1676 push:
1677         if (list_empty(&recv_ioctx->wait_list)) {
1678                 WARN_ON_ONCE(ch->processing_wait_list);
1679                 list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
1680         }
1681         goto out;
1682 }
1683 
1684 static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc)
1685 {
1686         struct srpt_rdma_ch *ch = cq->cq_context;
1687         struct srpt_recv_ioctx *ioctx =
1688                 container_of(wc->wr_cqe, struct srpt_recv_ioctx, ioctx.cqe);
1689 
1690         if (wc->status == IB_WC_SUCCESS) {
1691                 int req_lim;
1692 
1693                 req_lim = atomic_dec_return(&ch->req_lim);
1694                 if (unlikely(req_lim < 0))
1695                         pr_err("req_lim = %d < 0\n", req_lim);
1696                 ioctx->byte_len = wc->byte_len;
1697                 srpt_handle_new_iu(ch, ioctx);
1698         } else {
1699                 pr_info_ratelimited("receiving failed for ioctx %p with status %d\n",
1700                                     ioctx, wc->status);
1701         }
1702 }
1703 
1704 /*
1705  * This function must be called from the context in which RDMA completions are
1706  * processed because it accesses the wait list without protection against
1707  * access from other threads.
1708  */
1709 static void srpt_process_wait_list(struct srpt_rdma_ch *ch)
1710 {
1711         struct srpt_recv_ioctx *recv_ioctx, *tmp;
1712 
1713         WARN_ON_ONCE(ch->state == CH_CONNECTING);
1714 
1715         if (list_empty(&ch->cmd_wait_list))
1716                 return;
1717 
1718         WARN_ON_ONCE(ch->processing_wait_list);
1719         ch->processing_wait_list = true;
1720         list_for_each_entry_safe(recv_ioctx, tmp, &ch->cmd_wait_list,
1721                                  wait_list) {
1722                 if (!srpt_handle_new_iu(ch, recv_ioctx))
1723                         break;
1724         }
1725         ch->processing_wait_list = false;
1726 }
1727 
1728 /**
1729  * srpt_send_done - send completion callback
1730  * @cq: Completion queue.
1731  * @wc: Work completion.
1732  *
1733  * Note: Although this has not yet been observed during tests, at least in
1734  * theory it is possible that the srpt_get_send_ioctx() call invoked by
1735  * srpt_handle_new_iu() fails. This is possible because the req_lim_delta
1736  * value in each response is set to one, and it is possible that this response
1737  * makes the initiator send a new request before the send completion for that
1738  * response has been processed. This could e.g. happen if the call to
1739  * srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
1740  * if IB retransmission causes generation of the send completion to be
1741  * delayed. Incoming information units for which srpt_get_send_ioctx() fails
1742  * are queued on cmd_wait_list. The code below processes these delayed
1743  * requests one at a time.
1744  */
1745 static void srpt_send_done(struct ib_cq *cq, struct ib_wc *wc)
1746 {
1747         struct srpt_rdma_ch *ch = cq->cq_context;
1748         struct srpt_send_ioctx *ioctx =
1749                 container_of(wc->wr_cqe, struct srpt_send_ioctx, ioctx.cqe);
1750         enum srpt_command_state state;
1751 
1752         state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1753 
1754         WARN_ON(state != SRPT_STATE_CMD_RSP_SENT &&
1755                 state != SRPT_STATE_MGMT_RSP_SENT);
1756 
1757         atomic_add(1 + ioctx->n_rdma, &ch->sq_wr_avail);
1758 
1759         if (wc->status != IB_WC_SUCCESS)
1760                 pr_info("sending response for ioctx 0x%p failed with status %d\n",
1761                         ioctx, wc->status);
1762 
1763         if (state != SRPT_STATE_DONE) {
1764                 transport_generic_free_cmd(&ioctx->cmd, 0);
1765         } else {
1766                 pr_err("IB completion has been received too late for wr_id = %u.\n",
1767                        ioctx->ioctx.index);
1768         }
1769 
1770         srpt_process_wait_list(ch);
1771 }
1772 
1773 /**
1774  * srpt_create_ch_ib - create receive and send completion queues
1775  * @ch: SRPT RDMA channel.
1776  */
1777 static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
1778 {
1779         struct ib_qp_init_attr *qp_init;
1780         struct srpt_port *sport = ch->sport;
1781         struct srpt_device *sdev = sport->sdev;
1782         const struct ib_device_attr *attrs = &sdev->device->attrs;
1783         int sq_size = sport->port_attrib.srp_sq_size;
1784         int i, ret;
1785 
1786         WARN_ON(ch->rq_size < 1);
1787 
1788         ret = -ENOMEM;
1789         qp_init = kzalloc(sizeof(*qp_init), GFP_KERNEL);
1790         if (!qp_init)
1791                 goto out;
1792 
1793 retry:
1794         ch->cq = ib_alloc_cq_any(sdev->device, ch, ch->rq_size + sq_size,
1795                                  IB_POLL_WORKQUEUE);
1796         if (IS_ERR(ch->cq)) {
1797                 ret = PTR_ERR(ch->cq);
1798                 pr_err("failed to create CQ cqe= %d ret= %d\n",
1799                        ch->rq_size + sq_size, ret);
1800                 goto out;
1801         }
1802 
1803         qp_init->qp_context = (void *)ch;
1804         qp_init->event_handler
1805                 = (void(*)(struct ib_event *, void*))srpt_qp_event;
1806         qp_init->send_cq = ch->cq;
1807         qp_init->recv_cq = ch->cq;
1808         qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
1809         qp_init->qp_type = IB_QPT_RC;
1810         /*
1811          * We divide up our send queue size into half SEND WRs to send the
1812          * completions, and half R/W contexts to actually do the RDMA
1813          * READ/WRITE transfers.  Note that we need to allocate CQ slots for
1814          * both both, as RDMA contexts will also post completions for the
1815          * RDMA READ case.
1816          */
1817         qp_init->cap.max_send_wr = min(sq_size / 2, attrs->max_qp_wr);
1818         qp_init->cap.max_rdma_ctxs = sq_size / 2;
1819         qp_init->cap.max_send_sge = min(attrs->max_send_sge,
1820                                         SRPT_MAX_SG_PER_WQE);
1821         qp_init->cap.max_recv_sge = min(attrs->max_recv_sge,
1822                                         SRPT_MAX_SG_PER_WQE);
1823         qp_init->port_num = ch->sport->port;
1824         if (sdev->use_srq) {
1825                 qp_init->srq = sdev->srq;
1826         } else {
1827                 qp_init->cap.max_recv_wr = ch->rq_size;
1828                 qp_init->cap.max_recv_sge = min(attrs->max_recv_sge,
1829                                                 SRPT_MAX_SG_PER_WQE);
1830         }
1831 
1832         if (ch->using_rdma_cm) {
1833                 ret = rdma_create_qp(ch->rdma_cm.cm_id, sdev->pd, qp_init);
1834                 ch->qp = ch->rdma_cm.cm_id->qp;
1835         } else {
1836                 ch->qp = ib_create_qp(sdev->pd, qp_init);
1837                 if (!IS_ERR(ch->qp)) {
1838                         ret = srpt_init_ch_qp(ch, ch->qp);
1839                         if (ret)
1840                                 ib_destroy_qp(ch->qp);
1841                 } else {
1842                         ret = PTR_ERR(ch->qp);
1843                 }
1844         }
1845         if (ret) {
1846                 bool retry = sq_size > MIN_SRPT_SQ_SIZE;
1847 
1848                 if (retry) {
1849                         pr_debug("failed to create queue pair with sq_size = %d (%d) - retrying\n",
1850                                  sq_size, ret);
1851                         ib_free_cq(ch->cq);
1852                         sq_size = max(sq_size / 2, MIN_SRPT_SQ_SIZE);
1853                         goto retry;
1854                 } else {
1855                         pr_err("failed to create queue pair with sq_size = %d (%d)\n",
1856                                sq_size, ret);
1857                         goto err_destroy_cq;
1858                 }
1859         }
1860 
1861         atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
1862 
1863         pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d ch= %p\n",
1864                  __func__, ch->cq->cqe, qp_init->cap.max_send_sge,
1865                  qp_init->cap.max_send_wr, ch);
1866 
1867         if (!sdev->use_srq)
1868                 for (i = 0; i < ch->rq_size; i++)
1869                         srpt_post_recv(sdev, ch, ch->ioctx_recv_ring[i]);
1870 
1871 out:
1872         kfree(qp_init);
1873         return ret;
1874 
1875 err_destroy_cq:
1876         ch->qp = NULL;
1877         ib_free_cq(ch->cq);
1878         goto out;
1879 }
1880 
1881 static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
1882 {
1883         ib_destroy_qp(ch->qp);
1884         ib_free_cq(ch->cq);
1885 }
1886 
1887 /**
1888  * srpt_close_ch - close a RDMA channel
1889  * @ch: SRPT RDMA channel.
1890  *
1891  * Make sure all resources associated with the channel will be deallocated at
1892  * an appropriate time.
1893  *
1894  * Returns true if and only if the channel state has been modified into
1895  * CH_DRAINING.
1896  */
1897 static bool srpt_close_ch(struct srpt_rdma_ch *ch)
1898 {
1899         int ret;
1900 
1901         if (!srpt_set_ch_state(ch, CH_DRAINING)) {
1902                 pr_debug("%s: already closed\n", ch->sess_name);
1903                 return false;
1904         }
1905 
1906         kref_get(&ch->kref);
1907 
1908         ret = srpt_ch_qp_err(ch);
1909         if (ret < 0)
1910                 pr_err("%s-%d: changing queue pair into error state failed: %d\n",
1911                        ch->sess_name, ch->qp->qp_num, ret);
1912 
1913         ret = srpt_zerolength_write(ch);
1914         if (ret < 0) {
1915                 pr_err("%s-%d: queuing zero-length write failed: %d\n",
1916                        ch->sess_name, ch->qp->qp_num, ret);
1917                 if (srpt_set_ch_state(ch, CH_DISCONNECTED))
1918                         schedule_work(&ch->release_work);
1919                 else
1920                         WARN_ON_ONCE(true);
1921         }
1922 
1923         kref_put(&ch->kref, srpt_free_ch);
1924 
1925         return true;
1926 }
1927 
1928 /*
1929  * Change the channel state into CH_DISCONNECTING. If a channel has not yet
1930  * reached the connected state, close it. If a channel is in the connected
1931  * state, send a DREQ. If a DREQ has been received, send a DREP. Note: it is
1932  * the responsibility of the caller to ensure that this function is not
1933  * invoked concurrently with the code that accepts a connection. This means
1934  * that this function must either be invoked from inside a CM callback
1935  * function or that it must be invoked with the srpt_port.mutex held.
1936  */
1937 static int srpt_disconnect_ch(struct srpt_rdma_ch *ch)
1938 {
1939         int ret;
1940 
1941         if (!srpt_set_ch_state(ch, CH_DISCONNECTING))
1942                 return -ENOTCONN;
1943 
1944         if (ch->using_rdma_cm) {
1945                 ret = rdma_disconnect(ch->rdma_cm.cm_id);
1946         } else {
1947                 ret = ib_send_cm_dreq(ch->ib_cm.cm_id, NULL, 0);
1948                 if (ret < 0)
1949                         ret = ib_send_cm_drep(ch->ib_cm.cm_id, NULL, 0);
1950         }
1951 
1952         if (ret < 0 && srpt_close_ch(ch))
1953                 ret = 0;
1954 
1955         return ret;
1956 }
1957 
1958 static bool srpt_ch_closed(struct srpt_port *sport, struct srpt_rdma_ch *ch)
1959 {
1960         struct srpt_nexus *nexus;
1961         struct srpt_rdma_ch *ch2;
1962         bool res = true;
1963 
1964         rcu_read_lock();
1965         list_for_each_entry(nexus, &sport->nexus_list, entry) {
1966                 list_for_each_entry(ch2, &nexus->ch_list, list) {
1967                         if (ch2 == ch) {
1968                                 res = false;
1969                                 goto done;
1970                         }
1971                 }
1972         }
1973 done:
1974         rcu_read_unlock();
1975 
1976         return res;
1977 }
1978 
1979 /* Send DREQ and wait for DREP. */
1980 static void srpt_disconnect_ch_sync(struct srpt_rdma_ch *ch)
1981 {
1982         struct srpt_port *sport = ch->sport;
1983 
1984         pr_debug("ch %s-%d state %d\n", ch->sess_name, ch->qp->qp_num,
1985                  ch->state);
1986 
1987         mutex_lock(&sport->mutex);
1988         srpt_disconnect_ch(ch);
1989         mutex_unlock(&sport->mutex);
1990 
1991         while (wait_event_timeout(sport->ch_releaseQ, srpt_ch_closed(sport, ch),
1992                                   5 * HZ) == 0)
1993                 pr_info("%s(%s-%d state %d): still waiting ...\n", __func__,
1994                         ch->sess_name, ch->qp->qp_num, ch->state);
1995 
1996 }
1997 
1998 static void __srpt_close_all_ch(struct srpt_port *sport)
1999 {
2000         struct srpt_nexus *nexus;
2001         struct srpt_rdma_ch *ch;
2002 
2003         lockdep_assert_held(&sport->mutex);
2004 
2005         list_for_each_entry(nexus, &sport->nexus_list, entry) {
2006                 list_for_each_entry(ch, &nexus->ch_list, list) {
2007                         if (srpt_disconnect_ch(ch) >= 0)
2008                                 pr_info("Closing channel %s because target %s_%d has been disabled\n",
2009                                         ch->sess_name,
2010                                         dev_name(&sport->sdev->device->dev),
2011                                         sport->port);
2012                         srpt_close_ch(ch);
2013                 }
2014         }
2015 }
2016 
2017 /*
2018  * Look up (i_port_id, t_port_id) in sport->nexus_list. Create an entry if
2019  * it does not yet exist.
2020  */
2021 static struct srpt_nexus *srpt_get_nexus(struct srpt_port *sport,
2022                                          const u8 i_port_id[16],
2023                                          const u8 t_port_id[16])
2024 {
2025         struct srpt_nexus *nexus = NULL, *tmp_nexus = NULL, *n;
2026 
2027         for (;;) {
2028                 mutex_lock(&sport->mutex);
2029                 list_for_each_entry(n, &sport->nexus_list, entry) {
2030                         if (memcmp(n->i_port_id, i_port_id, 16) == 0 &&
2031                             memcmp(n->t_port_id, t_port_id, 16) == 0) {
2032                                 nexus = n;
2033                                 break;
2034                         }
2035                 }
2036                 if (!nexus && tmp_nexus) {
2037                         list_add_tail_rcu(&tmp_nexus->entry,
2038                                           &sport->nexus_list);
2039                         swap(nexus, tmp_nexus);
2040                 }
2041                 mutex_unlock(&sport->mutex);
2042 
2043                 if (nexus)
2044                         break;
2045                 tmp_nexus = kzalloc(sizeof(*nexus), GFP_KERNEL);
2046                 if (!tmp_nexus) {
2047                         nexus = ERR_PTR(-ENOMEM);
2048                         break;
2049                 }
2050                 INIT_LIST_HEAD(&tmp_nexus->ch_list);
2051                 memcpy(tmp_nexus->i_port_id, i_port_id, 16);
2052                 memcpy(tmp_nexus->t_port_id, t_port_id, 16);
2053         }
2054 
2055         kfree(tmp_nexus);
2056 
2057         return nexus;
2058 }
2059 
2060 static void srpt_set_enabled(struct srpt_port *sport, bool enabled)
2061         __must_hold(&sport->mutex)
2062 {
2063         lockdep_assert_held(&sport->mutex);
2064 
2065         if (sport->enabled == enabled)
2066                 return;
2067         sport->enabled = enabled;
2068         if (!enabled)
2069                 __srpt_close_all_ch(sport);
2070 }
2071 
2072 static void srpt_free_ch(struct kref *kref)
2073 {
2074         struct srpt_rdma_ch *ch = container_of(kref, struct srpt_rdma_ch, kref);
2075 
2076         kfree_rcu(ch, rcu);
2077 }
2078 
2079 /*
2080  * Shut down the SCSI target session, tell the connection manager to
2081  * disconnect the associated RDMA channel, transition the QP to the error
2082  * state and remove the channel from the channel list. This function is
2083  * typically called from inside srpt_zerolength_write_done(). Concurrent
2084  * srpt_zerolength_write() calls from inside srpt_close_ch() are possible
2085  * as long as the channel is on sport->nexus_list.
2086  */
2087 static void srpt_release_channel_work(struct work_struct *w)
2088 {
2089         struct srpt_rdma_ch *ch;
2090         struct srpt_device *sdev;
2091         struct srpt_port *sport;
2092         struct se_session *se_sess;
2093 
2094         ch = container_of(w, struct srpt_rdma_ch, release_work);
2095         pr_debug("%s-%d\n", ch->sess_name, ch->qp->qp_num);
2096 
2097         sdev = ch->sport->sdev;
2098         BUG_ON(!sdev);
2099 
2100         se_sess = ch->sess;
2101         BUG_ON(!se_sess);
2102 
2103         target_sess_cmd_list_set_waiting(se_sess);
2104         target_wait_for_sess_cmds(se_sess);
2105 
2106         target_remove_session(se_sess);
2107         ch->sess = NULL;
2108 
2109         if (ch->using_rdma_cm)
2110                 rdma_destroy_id(ch->rdma_cm.cm_id);
2111         else
2112                 ib_destroy_cm_id(ch->ib_cm.cm_id);
2113 
2114         sport = ch->sport;
2115         mutex_lock(&sport->mutex);
2116         list_del_rcu(&ch->list);
2117         mutex_unlock(&sport->mutex);
2118 
2119         srpt_destroy_ch_ib(ch);
2120 
2121         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2122                              ch->sport->sdev, ch->rq_size,
2123                              ch->rsp_buf_cache, DMA_TO_DEVICE);
2124 
2125         kmem_cache_destroy(ch->rsp_buf_cache);
2126 
2127         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
2128                              sdev, ch->rq_size,
2129                              ch->req_buf_cache, DMA_FROM_DEVICE);
2130 
2131         kmem_cache_destroy(ch->req_buf_cache);
2132 
2133         wake_up(&sport->ch_releaseQ);
2134 
2135         kref_put(&ch->kref, srpt_free_ch);
2136 }
2137 
2138 /**
2139  * srpt_cm_req_recv - process the event IB_CM_REQ_RECEIVED
2140  * @sdev: HCA through which the login request was received.
2141  * @ib_cm_id: IB/CM connection identifier in case of IB/CM.
2142  * @rdma_cm_id: RDMA/CM connection identifier in case of RDMA/CM.
2143  * @port_num: Port through which the REQ message was received.
2144  * @pkey: P_Key of the incoming connection.
2145  * @req: SRP login request.
2146  * @src_addr: GID (IB/CM) or IP address (RDMA/CM) of the port that submitted
2147  * the login request.
2148  *
2149  * Ownership of the cm_id is transferred to the target session if this
2150  * function returns zero. Otherwise the caller remains the owner of cm_id.
2151  */
2152 static int srpt_cm_req_recv(struct srpt_device *const sdev,
2153                             struct ib_cm_id *ib_cm_id,
2154                             struct rdma_cm_id *rdma_cm_id,
2155                             u8 port_num, __be16 pkey,
2156                             const struct srp_login_req *req,
2157                             const char *src_addr)
2158 {
2159         struct srpt_port *sport = &sdev->port[port_num - 1];
2160         struct srpt_nexus *nexus;
2161         struct srp_login_rsp *rsp = NULL;
2162         struct srp_login_rej *rej = NULL;
2163         union {
2164                 struct rdma_conn_param rdma_cm;
2165                 struct ib_cm_rep_param ib_cm;
2166         } *rep_param = NULL;
2167         struct srpt_rdma_ch *ch = NULL;
2168         char i_port_id[36];
2169         u32 it_iu_len;
2170         int i, tag_num, tag_size, ret;
2171 
2172         WARN_ON_ONCE(irqs_disabled());
2173 
2174         if (WARN_ON(!sdev || !req))
2175                 return -EINVAL;
2176 
2177         it_iu_len = be32_to_cpu(req->req_it_iu_len);
2178 
2179         pr_info("Received SRP_LOGIN_REQ with i_port_id %pI6, t_port_id %pI6 and it_iu_len %d on port %d (guid=%pI6); pkey %#04x\n",
2180                 req->initiator_port_id, req->target_port_id, it_iu_len,
2181                 port_num, &sport->gid, be16_to_cpu(pkey));
2182 
2183         nexus = srpt_get_nexus(sport, req->initiator_port_id,
2184                                req->target_port_id);
2185         if (IS_ERR(nexus)) {
2186                 ret = PTR_ERR(nexus);
2187                 goto out;
2188         }
2189 
2190         ret = -ENOMEM;
2191         rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
2192         rej = kzalloc(sizeof(*rej), GFP_KERNEL);
2193         rep_param = kzalloc(sizeof(*rep_param), GFP_KERNEL);
2194         if (!rsp || !rej || !rep_param)
2195                 goto out;
2196 
2197         ret = -EINVAL;
2198         if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
2199                 rej->reason = cpu_to_be32(
2200                                 SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
2201                 pr_err("rejected SRP_LOGIN_REQ because its length (%d bytes) is out of range (%d .. %d)\n",
2202                        it_iu_len, 64, srp_max_req_size);
2203                 goto reject;
2204         }
2205 
2206         if (!sport->enabled) {
2207                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2208                 pr_info("rejected SRP_LOGIN_REQ because target port %s_%d has not yet been enabled\n",
2209                         dev_name(&sport->sdev->device->dev), port_num);
2210                 goto reject;
2211         }
2212 
2213         if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
2214             || *(__be64 *)(req->target_port_id + 8) !=
2215                cpu_to_be64(srpt_service_guid)) {
2216                 rej->reason = cpu_to_be32(
2217                                 SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
2218                 pr_err("rejected SRP_LOGIN_REQ because it has an invalid target port identifier.\n");
2219                 goto reject;
2220         }
2221 
2222         ret = -ENOMEM;
2223         ch = kzalloc(sizeof(*ch), GFP_KERNEL);
2224         if (!ch) {
2225                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2226                 pr_err("rejected SRP_LOGIN_REQ because out of memory.\n");
2227                 goto reject;
2228         }
2229 
2230         kref_init(&ch->kref);
2231         ch->pkey = be16_to_cpu(pkey);
2232         ch->nexus = nexus;
2233         ch->zw_cqe.done = srpt_zerolength_write_done;
2234         INIT_WORK(&ch->release_work, srpt_release_channel_work);
2235         ch->sport = sport;
2236         if (ib_cm_id) {
2237                 ch->ib_cm.cm_id = ib_cm_id;
2238                 ib_cm_id->context = ch;
2239         } else {
2240                 ch->using_rdma_cm = true;
2241                 ch->rdma_cm.cm_id = rdma_cm_id;
2242                 rdma_cm_id->context = ch;
2243         }
2244         /*
2245          * ch->rq_size should be at least as large as the initiator queue
2246          * depth to avoid that the initiator driver has to report QUEUE_FULL
2247          * to the SCSI mid-layer.
2248          */
2249         ch->rq_size = min(MAX_SRPT_RQ_SIZE, sdev->device->attrs.max_qp_wr);
2250         spin_lock_init(&ch->spinlock);
2251         ch->state = CH_CONNECTING;
2252         INIT_LIST_HEAD(&ch->cmd_wait_list);
2253         ch->max_rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
2254 
2255         ch->rsp_buf_cache = kmem_cache_create("srpt-rsp-buf", ch->max_rsp_size,
2256                                               512, 0, NULL);
2257         if (!ch->rsp_buf_cache)
2258                 goto free_ch;
2259 
2260         ch->ioctx_ring = (struct srpt_send_ioctx **)
2261                 srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2262                                       sizeof(*ch->ioctx_ring[0]),
2263                                       ch->rsp_buf_cache, 0, DMA_TO_DEVICE);
2264         if (!ch->ioctx_ring) {
2265                 pr_err("rejected SRP_LOGIN_REQ because creating a new QP SQ ring failed.\n");
2266                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2267                 goto free_rsp_cache;
2268         }
2269 
2270         for (i = 0; i < ch->rq_size; i++)
2271                 ch->ioctx_ring[i]->ch = ch;
2272         if (!sdev->use_srq) {
2273                 u16 imm_data_offset = req->req_flags & SRP_IMMED_REQUESTED ?
2274                         be16_to_cpu(req->imm_data_offset) : 0;
2275                 u16 alignment_offset;
2276                 u32 req_sz;
2277 
2278                 if (req->req_flags & SRP_IMMED_REQUESTED)
2279                         pr_debug("imm_data_offset = %d\n",
2280                                  be16_to_cpu(req->imm_data_offset));
2281                 if (imm_data_offset >= sizeof(struct srp_cmd)) {
2282                         ch->imm_data_offset = imm_data_offset;
2283                         rsp->rsp_flags |= SRP_LOGIN_RSP_IMMED_SUPP;
2284                 } else {
2285                         ch->imm_data_offset = 0;
2286                 }
2287                 alignment_offset = round_up(imm_data_offset, 512) -
2288                         imm_data_offset;
2289                 req_sz = alignment_offset + imm_data_offset + srp_max_req_size;
2290                 ch->req_buf_cache = kmem_cache_create("srpt-req-buf", req_sz,
2291                                                       512, 0, NULL);
2292                 if (!ch->req_buf_cache)
2293                         goto free_rsp_ring;
2294 
2295                 ch->ioctx_recv_ring = (struct srpt_recv_ioctx **)
2296                         srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2297                                               sizeof(*ch->ioctx_recv_ring[0]),
2298                                               ch->req_buf_cache,
2299                                               alignment_offset,
2300                                               DMA_FROM_DEVICE);
2301                 if (!ch->ioctx_recv_ring) {
2302                         pr_err("rejected SRP_LOGIN_REQ because creating a new QP RQ ring failed.\n");
2303                         rej->reason =
2304                             cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2305                         goto free_recv_cache;
2306                 }
2307                 for (i = 0; i < ch->rq_size; i++)
2308                         INIT_LIST_HEAD(&ch->ioctx_recv_ring[i]->wait_list);
2309         }
2310 
2311         ret = srpt_create_ch_ib(ch);
2312         if (ret) {
2313                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2314                 pr_err("rejected SRP_LOGIN_REQ because creating a new RDMA channel failed.\n");
2315                 goto free_recv_ring;
2316         }
2317 
2318         strlcpy(ch->sess_name, src_addr, sizeof(ch->sess_name));
2319         snprintf(i_port_id, sizeof(i_port_id), "0x%016llx%016llx",
2320                         be64_to_cpu(*(__be64 *)nexus->i_port_id),
2321                         be64_to_cpu(*(__be64 *)(nexus->i_port_id + 8)));
2322 
2323         pr_debug("registering session %s\n", ch->sess_name);
2324 
2325         tag_num = ch->rq_size;
2326         tag_size = 1; /* ib_srpt does not use se_sess->sess_cmd_map */
2327         if (sport->port_guid_tpg.se_tpg_wwn)
2328                 ch->sess = target_setup_session(&sport->port_guid_tpg, tag_num,
2329                                                 tag_size, TARGET_PROT_NORMAL,
2330                                                 ch->sess_name, ch, NULL);
2331         if (sport->port_gid_tpg.se_tpg_wwn && IS_ERR_OR_NULL(ch->sess))
2332                 ch->sess = target_setup_session(&sport->port_gid_tpg, tag_num,
2333                                         tag_size, TARGET_PROT_NORMAL, i_port_id,
2334                                         ch, NULL);
2335         /* Retry without leading "0x" */
2336         if (sport->port_gid_tpg.se_tpg_wwn && IS_ERR_OR_NULL(ch->sess))
2337                 ch->sess = target_setup_session(&sport->port_gid_tpg, tag_num,
2338                                                 tag_size, TARGET_PROT_NORMAL,
2339                                                 i_port_id + 2, ch, NULL);
2340         if (IS_ERR_OR_NULL(ch->sess)) {
2341                 WARN_ON_ONCE(ch->sess == NULL);
2342                 ret = PTR_ERR(ch->sess);
2343                 ch->sess = NULL;
2344                 pr_info("Rejected login for initiator %s: ret = %d.\n",
2345                         ch->sess_name, ret);
2346                 rej->reason = cpu_to_be32(ret == -ENOMEM ?
2347                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES :
2348                                 SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
2349                 goto destroy_ib;
2350         }
2351 
2352         mutex_lock(&sport->mutex);
2353 
2354         if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
2355                 struct srpt_rdma_ch *ch2;
2356 
2357                 list_for_each_entry(ch2, &nexus->ch_list, list) {
2358                         if (srpt_disconnect_ch(ch2) < 0)
2359                                 continue;
2360                         pr_info("Relogin - closed existing channel %s\n",
2361                                 ch2->sess_name);
2362                         rsp->rsp_flags |= SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
2363                 }
2364         } else {
2365                 rsp->rsp_flags |= SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
2366         }
2367 
2368         list_add_tail_rcu(&ch->list, &nexus->ch_list);
2369 
2370         if (!sport->enabled) {
2371                 rej->reason = cpu_to_be32(
2372                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2373                 pr_info("rejected SRP_LOGIN_REQ because target %s_%d is not enabled\n",
2374                         dev_name(&sdev->device->dev), port_num);
2375                 mutex_unlock(&sport->mutex);
2376                 goto reject;
2377         }
2378 
2379         mutex_unlock(&sport->mutex);
2380 
2381         ret = ch->using_rdma_cm ? 0 : srpt_ch_qp_rtr(ch, ch->qp);
2382         if (ret) {
2383                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2384                 pr_err("rejected SRP_LOGIN_REQ because enabling RTR failed (error code = %d)\n",
2385                        ret);
2386                 goto reject;
2387         }
2388 
2389         pr_debug("Establish connection sess=%p name=%s ch=%p\n", ch->sess,
2390                  ch->sess_name, ch);
2391 
2392         /* create srp_login_response */
2393         rsp->opcode = SRP_LOGIN_RSP;
2394         rsp->tag = req->tag;
2395         rsp->max_it_iu_len = cpu_to_be32(srp_max_req_size);
2396         rsp->max_ti_iu_len = req->req_it_iu_len;
2397         ch->max_ti_iu_len = it_iu_len;
2398         rsp->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
2399                                    SRP_BUF_FORMAT_INDIRECT);
2400         rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
2401         atomic_set(&ch->req_lim, ch->rq_size);
2402         atomic_set(&ch->req_lim_delta, 0);
2403 
2404         /* create cm reply */
2405         if (ch->using_rdma_cm) {
2406                 rep_param->rdma_cm.private_data = (void *)rsp;
2407                 rep_param->rdma_cm.private_data_len = sizeof(*rsp);
2408                 rep_param->rdma_cm.rnr_retry_count = 7;
2409                 rep_param->rdma_cm.flow_control = 1;
2410                 rep_param->rdma_cm.responder_resources = 4;
2411                 rep_param->rdma_cm.initiator_depth = 4;
2412         } else {
2413                 rep_param->ib_cm.qp_num = ch->qp->qp_num;
2414                 rep_param->ib_cm.private_data = (void *)rsp;
2415                 rep_param->ib_cm.private_data_len = sizeof(*rsp);
2416                 rep_param->ib_cm.rnr_retry_count = 7;
2417                 rep_param->ib_cm.flow_control = 1;
2418                 rep_param->ib_cm.failover_accepted = 0;
2419                 rep_param->ib_cm.srq = 1;
2420                 rep_param->ib_cm.responder_resources = 4;
2421                 rep_param->ib_cm.initiator_depth = 4;
2422         }
2423 
2424         /*
2425          * Hold the sport mutex while accepting a connection to avoid that
2426          * srpt_disconnect_ch() is invoked concurrently with this code.
2427          */
2428         mutex_lock(&sport->mutex);
2429         if (sport->enabled && ch->state == CH_CONNECTING) {
2430                 if (ch->using_rdma_cm)
2431                         ret = rdma_accept(rdma_cm_id, &rep_param->rdma_cm);
2432                 else
2433                         ret = ib_send_cm_rep(ib_cm_id, &rep_param->ib_cm);
2434         } else {
2435                 ret = -EINVAL;
2436         }
2437         mutex_unlock(&sport->mutex);
2438 
2439         switch (ret) {
2440         case 0:
2441                 break;
2442         case -EINVAL:
2443                 goto reject;
2444         default:
2445                 rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2446                 pr_err("sending SRP_LOGIN_REQ response failed (error code = %d)\n",
2447                        ret);
2448                 goto reject;
2449         }
2450 
2451         goto out;
2452 
2453 destroy_ib:
2454         srpt_destroy_ch_ib(ch);
2455 
2456 free_recv_ring:
2457         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
2458                              ch->sport->sdev, ch->rq_size,
2459                              ch->req_buf_cache, DMA_FROM_DEVICE);
2460 
2461 free_recv_cache:
2462         kmem_cache_destroy(ch->req_buf_cache);
2463 
2464 free_rsp_ring:
2465         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2466                              ch->sport->sdev, ch->rq_size,
2467                              ch->rsp_buf_cache, DMA_TO_DEVICE);
2468 
2469 free_rsp_cache:
2470         kmem_cache_destroy(ch->rsp_buf_cache);
2471 
2472 free_ch:
2473         if (rdma_cm_id)
2474                 rdma_cm_id->context = NULL;
2475         else
2476                 ib_cm_id->context = NULL;
2477         kfree(ch);
2478         ch = NULL;
2479 
2480         WARN_ON_ONCE(ret == 0);
2481 
2482 reject:
2483         pr_info("Rejecting login with reason %#x\n", be32_to_cpu(rej->reason));
2484         rej->opcode = SRP_LOGIN_REJ;
2485         rej->tag = req->tag;
2486         rej->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
2487                                    SRP_BUF_FORMAT_INDIRECT);
2488 
2489         if (rdma_cm_id)
2490                 rdma_reject(rdma_cm_id, rej, sizeof(*rej));
2491         else
2492                 ib_send_cm_rej(ib_cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
2493                                rej, sizeof(*rej));
2494 
2495         if (ch && ch->sess) {
2496                 srpt_close_ch(ch);
2497                 /*
2498                  * Tell the caller not to free cm_id since
2499                  * srpt_release_channel_work() will do that.
2500                  */
2501                 ret = 0;
2502         }
2503 
2504 out:
2505         kfree(rep_param);
2506         kfree(rsp);
2507         kfree(rej);
2508 
2509         return ret;
2510 }
2511 
2512 static int srpt_ib_cm_req_recv(struct ib_cm_id *cm_id,
2513                                const struct ib_cm_req_event_param *param,
2514                                void *private_data)
2515 {
2516         char sguid[40];
2517 
2518         srpt_format_guid(sguid, sizeof(sguid),
2519                          &param->primary_path->dgid.global.interface_id);
2520 
2521         return srpt_cm_req_recv(cm_id->context, cm_id, NULL, param->port,
2522                                 param->primary_path->pkey,
2523                                 private_data, sguid);
2524 }
2525 
2526 static int srpt_rdma_cm_req_recv(struct rdma_cm_id *cm_id,
2527                                  struct rdma_cm_event *event)
2528 {
2529         struct srpt_device *sdev;
2530         struct srp_login_req req;
2531         const struct srp_login_req_rdma *req_rdma;
2532         char src_addr[40];
2533 
2534         sdev = ib_get_client_data(cm_id->device, &srpt_client);
2535         if (!sdev)
2536                 return -ECONNREFUSED;
2537 
2538         if (event->param.conn.private_data_len < sizeof(*req_rdma))
2539                 return -EINVAL;
2540 
2541         /* Transform srp_login_req_rdma into srp_login_req. */
2542         req_rdma = event->param.conn.private_data;
2543         memset(&req, 0, sizeof(req));
2544         req.opcode              = req_rdma->opcode;
2545         req.tag                 = req_rdma->tag;
2546         req.req_it_iu_len       = req_rdma->req_it_iu_len;
2547         req.req_buf_fmt         = req_rdma->req_buf_fmt;
2548         req.req_flags           = req_rdma->req_flags;
2549         memcpy(req.initiator_port_id, req_rdma->initiator_port_id, 16);
2550         memcpy(req.target_port_id, req_rdma->target_port_id, 16);
2551         req.imm_data_offset     = req_rdma->imm_data_offset;
2552 
2553         snprintf(src_addr, sizeof(src_addr), "%pIS",
2554                  &cm_id->route.addr.src_addr);
2555 
2556         return srpt_cm_req_recv(sdev, NULL, cm_id, cm_id->port_num,
2557                                 cm_id->route.path_rec->pkey, &req, src_addr);
2558 }
2559 
2560 static void srpt_cm_rej_recv(struct srpt_rdma_ch *ch,
2561                              enum ib_cm_rej_reason reason,
2562                              const u8 *private_data,
2563                              u8 private_data_len)
2564 {
2565         char *priv = NULL;
2566         int i;
2567 
2568         if (private_data_len && (priv = kmalloc(private_data_len * 3 + 1,
2569                                                 GFP_KERNEL))) {
2570                 for (i = 0; i < private_data_len; i++)
2571                         sprintf(priv + 3 * i, " %02x", private_data[i]);
2572         }
2573         pr_info("Received CM REJ for ch %s-%d; reason %d%s%s.\n",
2574                 ch->sess_name, ch->qp->qp_num, reason, private_data_len ?
2575                 "; private data" : "", priv ? priv : " (?)");
2576         kfree(priv);
2577 }
2578 
2579 /**
2580  * srpt_cm_rtu_recv - process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event
2581  * @ch: SRPT RDMA channel.
2582  *
2583  * An RTU (ready to use) message indicates that the connection has been
2584  * established and that the recipient may begin transmitting.
2585  */
2586 static void srpt_cm_rtu_recv(struct srpt_rdma_ch *ch)
2587 {
2588         int ret;
2589 
2590         ret = ch->using_rdma_cm ? 0 : srpt_ch_qp_rts(ch, ch->qp);
2591         if (ret < 0) {
2592                 pr_err("%s-%d: QP transition to RTS failed\n", ch->sess_name,
2593                        ch->qp->qp_num);
2594                 srpt_close_ch(ch);
2595                 return;
2596         }
2597 
2598         /*
2599          * Note: calling srpt_close_ch() if the transition to the LIVE state
2600          * fails is not necessary since that means that that function has
2601          * already been invoked from another thread.
2602          */
2603         if (!srpt_set_ch_state(ch, CH_LIVE)) {
2604                 pr_err("%s-%d: channel transition to LIVE state failed\n",
2605                        ch->sess_name, ch->qp->qp_num);
2606                 return;
2607         }
2608 
2609         /* Trigger wait list processing. */
2610         ret = srpt_zerolength_write(ch);
2611         WARN_ONCE(ret < 0, "%d\n", ret);
2612 }
2613 
2614 /**
2615  * srpt_cm_handler - IB connection manager callback function
2616  * @cm_id: IB/CM connection identifier.
2617  * @event: IB/CM event.
2618  *
2619  * A non-zero return value will cause the caller destroy the CM ID.
2620  *
2621  * Note: srpt_cm_handler() must only return a non-zero value when transferring
2622  * ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
2623  * a non-zero value in any other case will trigger a race with the
2624  * ib_destroy_cm_id() call in srpt_release_channel().
2625  */
2626 static int srpt_cm_handler(struct ib_cm_id *cm_id,
2627                            const struct ib_cm_event *event)
2628 {
2629         struct srpt_rdma_ch *ch = cm_id->context;
2630         int ret;
2631 
2632         ret = 0;
2633         switch (event->event) {
2634         case IB_CM_REQ_RECEIVED:
2635                 ret = srpt_ib_cm_req_recv(cm_id, &event->param.req_rcvd,
2636                                           event->private_data);
2637                 break;
2638         case IB_CM_REJ_RECEIVED:
2639                 srpt_cm_rej_recv(ch, event->param.rej_rcvd.reason,
2640                                  event->private_data,
2641                                  IB_CM_REJ_PRIVATE_DATA_SIZE);
2642                 break;
2643         case IB_CM_RTU_RECEIVED:
2644         case IB_CM_USER_ESTABLISHED:
2645                 srpt_cm_rtu_recv(ch);
2646                 break;
2647         case IB_CM_DREQ_RECEIVED:
2648                 srpt_disconnect_ch(ch);
2649                 break;
2650         case IB_CM_DREP_RECEIVED:
2651                 pr_info("Received CM DREP message for ch %s-%d.\n",
2652                         ch->sess_name, ch->qp->qp_num);
2653                 srpt_close_ch(ch);
2654                 break;
2655         case IB_CM_TIMEWAIT_EXIT:
2656                 pr_info("Received CM TimeWait exit for ch %s-%d.\n",
2657                         ch->sess_name, ch->qp->qp_num);
2658                 srpt_close_ch(ch);
2659                 break;
2660         case IB_CM_REP_ERROR:
2661                 pr_info("Received CM REP error for ch %s-%d.\n", ch->sess_name,
2662                         ch->qp->qp_num);
2663                 break;
2664         case IB_CM_DREQ_ERROR:
2665                 pr_info("Received CM DREQ ERROR event.\n");
2666                 break;
2667         case IB_CM_MRA_RECEIVED:
2668                 pr_info("Received CM MRA event\n");
2669                 break;
2670         default:
2671                 pr_err("received unrecognized CM event %d\n", event->event);
2672                 break;
2673         }
2674 
2675         return ret;
2676 }
2677 
2678 static int srpt_rdma_cm_handler(struct rdma_cm_id *cm_id,
2679                                 struct rdma_cm_event *event)
2680 {
2681         struct srpt_rdma_ch *ch = cm_id->context;
2682         int ret = 0;
2683 
2684         switch (event->event) {
2685         case RDMA_CM_EVENT_CONNECT_REQUEST:
2686                 ret = srpt_rdma_cm_req_recv(cm_id, event);
2687                 break;
2688         case RDMA_CM_EVENT_REJECTED:
2689                 srpt_cm_rej_recv(ch, event->status,
2690                                  event->param.conn.private_data,
2691                                  event->param.conn.private_data_len);
2692                 break;
2693         case RDMA_CM_EVENT_ESTABLISHED:
2694                 srpt_cm_rtu_recv(ch);
2695                 break;
2696         case RDMA_CM_EVENT_DISCONNECTED:
2697                 if (ch->state < CH_DISCONNECTING)
2698                         srpt_disconnect_ch(ch);
2699                 else
2700                         srpt_close_ch(ch);
2701                 break;
2702         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2703                 srpt_close_ch(ch);
2704                 break;
2705         case RDMA_CM_EVENT_UNREACHABLE:
2706                 pr_info("Received CM REP error for ch %s-%d.\n", ch->sess_name,
2707                         ch->qp->qp_num);
2708                 break;
2709         case RDMA_CM_EVENT_DEVICE_REMOVAL:
2710         case RDMA_CM_EVENT_ADDR_CHANGE:
2711                 break;
2712         default:
2713                 pr_err("received unrecognized RDMA CM event %d\n",
2714                        event->event);
2715                 break;
2716         }
2717 
2718         return ret;
2719 }
2720 
2721 /*
2722  * srpt_write_pending - Start data transfer from initiator to target (write).
2723  */
2724 static int srpt_write_pending(struct se_cmd *se_cmd)
2725 {
2726         struct srpt_send_ioctx *ioctx =
2727                 container_of(se_cmd, struct srpt_send_ioctx, cmd);
2728         struct srpt_rdma_ch *ch = ioctx->ch;
2729         struct ib_send_wr *first_wr = NULL;
2730         struct ib_cqe *cqe = &ioctx->rdma_cqe;
2731         enum srpt_command_state new_state;
2732         int ret, i;
2733 
2734         if (ioctx->recv_ioctx) {
2735                 srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
2736                 target_execute_cmd(&ioctx->cmd);
2737                 return 0;
2738         }
2739 
2740         new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
2741         WARN_ON(new_state == SRPT_STATE_DONE);
2742 
2743         if (atomic_sub_return(ioctx->n_rdma, &ch->sq_wr_avail) < 0) {
2744                 pr_warn("%s: IB send queue full (needed %d)\n",
2745                                 __func__, ioctx->n_rdma);
2746                 ret = -ENOMEM;
2747                 goto out_undo;
2748         }
2749 
2750         cqe->done = srpt_rdma_read_done;
2751         for (i = ioctx->n_rw_ctx - 1; i >= 0; i--) {
2752                 struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
2753 
2754                 first_wr = rdma_rw_ctx_wrs(&ctx->rw, ch->qp, ch->sport->port,
2755                                 cqe, first_wr);
2756                 cqe = NULL;
2757         }
2758 
2759         ret = ib_post_send(ch->qp, first_wr, NULL);
2760         if (ret) {
2761                 pr_err("%s: ib_post_send() returned %d for %d (avail: %d)\n",
2762                          __func__, ret, ioctx->n_rdma,
2763                          atomic_read(&ch->sq_wr_avail));
2764                 goto out_undo;
2765         }
2766 
2767         return 0;
2768 out_undo:
2769         atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
2770         return ret;
2771 }
2772 
2773 static u8 tcm_to_srp_tsk_mgmt_status(const int tcm_mgmt_status)
2774 {
2775         switch (tcm_mgmt_status) {
2776         case TMR_FUNCTION_COMPLETE:
2777                 return SRP_TSK_MGMT_SUCCESS;
2778         case TMR_FUNCTION_REJECTED:
2779                 return SRP_TSK_MGMT_FUNC_NOT_SUPP;
2780         }
2781         return SRP_TSK_MGMT_FAILED;
2782 }
2783 
2784 /**
2785  * srpt_queue_response - transmit the response to a SCSI command
2786  * @cmd: SCSI target command.
2787  *
2788  * Callback function called by the TCM core. Must not block since it can be
2789  * invoked on the context of the IB completion handler.
2790  */
2791 static void srpt_queue_response(struct se_cmd *cmd)
2792 {
2793         struct srpt_send_ioctx *ioctx =
2794                 container_of(cmd, struct srpt_send_ioctx, cmd);
2795         struct srpt_rdma_ch *ch = ioctx->ch;
2796         struct srpt_device *sdev = ch->sport->sdev;
2797         struct ib_send_wr send_wr, *first_wr = &send_wr;
2798         struct ib_sge sge;
2799         enum srpt_command_state state;
2800         int resp_len, ret, i;
2801         u8 srp_tm_status;
2802 
2803         BUG_ON(!ch);
2804 
2805         state = ioctx->state;
2806         switch (state) {
2807         case SRPT_STATE_NEW:
2808         case SRPT_STATE_DATA_IN:
2809                 ioctx->state = SRPT_STATE_CMD_RSP_SENT;
2810                 break;
2811         case SRPT_STATE_MGMT:
2812                 ioctx->state = SRPT_STATE_MGMT_RSP_SENT;
2813                 break;
2814         default:
2815                 WARN(true, "ch %p; cmd %d: unexpected command state %d\n",
2816                         ch, ioctx->ioctx.index, ioctx->state);
2817                 break;
2818         }
2819 
2820         if (WARN_ON_ONCE(state == SRPT_STATE_CMD_RSP_SENT))
2821                 return;
2822 
2823         /* For read commands, transfer the data to the initiator. */
2824         if (ioctx->cmd.data_direction == DMA_FROM_DEVICE &&
2825             ioctx->cmd.data_length &&
2826             !ioctx->queue_status_only) {
2827                 for (i = ioctx->n_rw_ctx - 1; i >= 0; i--) {
2828                         struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
2829 
2830                         first_wr = rdma_rw_ctx_wrs(&ctx->rw, ch->qp,
2831                                         ch->sport->port, NULL, first_wr);
2832                 }
2833         }
2834 
2835         if (state != SRPT_STATE_MGMT)
2836                 resp_len = srpt_build_cmd_rsp(ch, ioctx, ioctx->cmd.tag,
2837                                               cmd->scsi_status);
2838         else {
2839                 srp_tm_status
2840                         = tcm_to_srp_tsk_mgmt_status(cmd->se_tmr_req->response);
2841                 resp_len = srpt_build_tskmgmt_rsp(ch, ioctx, srp_tm_status,
2842                                                  ioctx->cmd.tag);
2843         }
2844 
2845         atomic_inc(&ch->req_lim);
2846 
2847         if (unlikely(atomic_sub_return(1 + ioctx->n_rdma,
2848                         &ch->sq_wr_avail) < 0)) {
2849                 pr_warn("%s: IB send queue full (needed %d)\n",
2850                                 __func__, ioctx->n_rdma);
2851                 ret = -ENOMEM;
2852                 goto out;
2853         }
2854 
2855         ib_dma_sync_single_for_device(sdev->device, ioctx->ioctx.dma, resp_len,
2856                                       DMA_TO_DEVICE);
2857 
2858         sge.addr = ioctx->ioctx.dma;
2859         sge.length = resp_len;
2860         sge.lkey = sdev->lkey;
2861 
2862         ioctx->ioctx.cqe.done = srpt_send_done;
2863         send_wr.next = NULL;
2864         send_wr.wr_cqe = &ioctx->ioctx.cqe;
2865         send_wr.sg_list = &sge;
2866         send_wr.num_sge = 1;
2867         send_wr.opcode = IB_WR_SEND;
2868         send_wr.send_flags = IB_SEND_SIGNALED;
2869 
2870         ret = ib_post_send(ch->qp, first_wr, NULL);
2871         if (ret < 0) {
2872                 pr_err("%s: sending cmd response failed for tag %llu (%d)\n",
2873                         __func__, ioctx->cmd.tag, ret);
2874                 goto out;
2875         }
2876 
2877         return;
2878 
2879 out:
2880         atomic_add(1 + ioctx->n_rdma, &ch->sq_wr_avail);
2881         atomic_dec(&ch->req_lim);
2882         srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
2883         target_put_sess_cmd(&ioctx->cmd);
2884 }
2885 
2886 static int srpt_queue_data_in(struct se_cmd *cmd)
2887 {
2888         srpt_queue_response(cmd);
2889         return 0;
2890 }
2891 
2892 static void srpt_queue_tm_rsp(struct se_cmd *cmd)
2893 {
2894         srpt_queue_response(cmd);
2895 }
2896 
2897 /*
2898  * This function is called for aborted commands if no response is sent to the
2899  * initiator. Make sure that the credits freed by aborting a command are
2900  * returned to the initiator the next time a response is sent by incrementing
2901  * ch->req_lim_delta.
2902  */
2903 static void srpt_aborted_task(struct se_cmd *cmd)
2904 {
2905         struct srpt_send_ioctx *ioctx = container_of(cmd,
2906                                 struct srpt_send_ioctx, cmd);
2907         struct srpt_rdma_ch *ch = ioctx->ch;
2908 
2909         atomic_inc(&ch->req_lim_delta);
2910 }
2911 
2912 static int srpt_queue_status(struct se_cmd *cmd)
2913 {
2914         struct srpt_send_ioctx *ioctx;
2915 
2916         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
2917         BUG_ON(ioctx->sense_data != cmd->sense_buffer);
2918         if (cmd->se_cmd_flags &
2919             (SCF_TRANSPORT_TASK_SENSE | SCF_EMULATED_TASK_SENSE))
2920                 WARN_ON(cmd->scsi_status != SAM_STAT_CHECK_CONDITION);
2921         ioctx->queue_status_only = true;
2922         srpt_queue_response(cmd);
2923         return 0;
2924 }
2925 
2926 static void srpt_refresh_port_work(struct work_struct *work)
2927 {
2928         struct srpt_port *sport = container_of(work, struct srpt_port, work);
2929 
2930         srpt_refresh_port(sport);
2931 }
2932 
2933 static bool srpt_ch_list_empty(struct srpt_port *sport)
2934 {
2935         struct srpt_nexus *nexus;
2936         bool res = true;
2937 
2938         rcu_read_lock();
2939         list_for_each_entry(nexus, &sport->nexus_list, entry)
2940                 if (!list_empty(&nexus->ch_list))
2941                         res = false;
2942         rcu_read_unlock();
2943 
2944         return res;
2945 }
2946 
2947 /**
2948  * srpt_release_sport - disable login and wait for associated channels
2949  * @sport: SRPT HCA port.
2950  */
2951 static int srpt_release_sport(struct srpt_port *sport)
2952 {
2953         struct srpt_nexus *nexus, *next_n;
2954         struct srpt_rdma_ch *ch;
2955 
2956         WARN_ON_ONCE(irqs_disabled());
2957 
2958         mutex_lock(&sport->mutex);
2959         srpt_set_enabled(sport, false);
2960         mutex_unlock(&sport->mutex);
2961 
2962         while (wait_event_timeout(sport->ch_releaseQ,
2963                                   srpt_ch_list_empty(sport), 5 * HZ) <= 0) {
2964                 pr_info("%s_%d: waiting for session unregistration ...\n",
2965                         dev_name(&sport->sdev->device->dev), sport->port);
2966                 rcu_read_lock();
2967                 list_for_each_entry(nexus, &sport->nexus_list, entry) {
2968                         list_for_each_entry(ch, &nexus->ch_list, list) {
2969                                 pr_info("%s-%d: state %s\n",
2970                                         ch->sess_name, ch->qp->qp_num,
2971                                         get_ch_state_name(ch->state));
2972                         }
2973                 }
2974                 rcu_read_unlock();
2975         }
2976 
2977         mutex_lock(&sport->mutex);
2978         list_for_each_entry_safe(nexus, next_n, &sport->nexus_list, entry) {
2979                 list_del(&nexus->entry);
2980                 kfree_rcu(nexus, rcu);
2981         }
2982         mutex_unlock(&sport->mutex);
2983 
2984         return 0;
2985 }
2986 
2987 static struct se_wwn *__srpt_lookup_wwn(const char *name)
2988 {
2989         struct ib_device *dev;
2990         struct srpt_device *sdev;
2991         struct srpt_port *sport;
2992         int i;
2993 
2994         list_for_each_entry(sdev, &srpt_dev_list, list) {
2995                 dev = sdev->device;
2996                 if (!dev)
2997                         continue;
2998 
2999                 for (i = 0; i < dev->phys_port_cnt; i++) {
3000                         sport = &sdev->port[i];
3001 
3002                         if (strcmp(sport->port_guid, name) == 0)
3003                                 return &sport->port_guid_wwn;
3004                         if (strcmp(sport->port_gid, name) == 0)
3005                                 return &sport->port_gid_wwn;
3006                 }
3007         }
3008 
3009         return NULL;
3010 }
3011 
3012 static struct se_wwn *srpt_lookup_wwn(const char *name)
3013 {
3014         struct se_wwn *wwn;
3015 
3016         spin_lock(&srpt_dev_lock);
3017         wwn = __srpt_lookup_wwn(name);
3018         spin_unlock(&srpt_dev_lock);
3019 
3020         return wwn;
3021 }
3022 
3023 static void srpt_free_srq(struct srpt_device *sdev)
3024 {
3025         if (!sdev->srq)
3026                 return;
3027 
3028         ib_destroy_srq(sdev->srq);
3029         srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3030                              sdev->srq_size, sdev->req_buf_cache,
3031                              DMA_FROM_DEVICE);
3032         kmem_cache_destroy(sdev->req_buf_cache);
3033         sdev->srq = NULL;
3034 }
3035 
3036 static int srpt_alloc_srq(struct srpt_device *sdev)
3037 {
3038         struct ib_srq_init_attr srq_attr = {
3039                 .event_handler = srpt_srq_event,
3040                 .srq_context = (void *)sdev,
3041                 .attr.max_wr = sdev->srq_size,
3042                 .attr.max_sge = 1,
3043                 .srq_type = IB_SRQT_BASIC,
3044         };
3045         struct ib_device *device = sdev->device;
3046         struct ib_srq *srq;
3047         int i;
3048 
3049         WARN_ON_ONCE(sdev->srq);
3050         srq = ib_create_srq(sdev->pd, &srq_attr);
3051         if (IS_ERR(srq)) {
3052                 pr_debug("ib_create_srq() failed: %ld\n", PTR_ERR(srq));
3053                 return PTR_ERR(srq);
3054         }
3055 
3056         pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n", sdev->srq_size,
3057                  sdev->device->attrs.max_srq_wr, dev_name(&device->dev));
3058 
3059         sdev->req_buf_cache = kmem_cache_create("srpt-srq-req-buf",
3060                                                 srp_max_req_size, 0, 0, NULL);
3061         if (!sdev->req_buf_cache)
3062                 goto free_srq;
3063 
3064         sdev->ioctx_ring = (struct srpt_recv_ioctx **)
3065                 srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
3066                                       sizeof(*sdev->ioctx_ring[0]),
3067                                       sdev->req_buf_cache, 0, DMA_FROM_DEVICE);
3068         if (!sdev->ioctx_ring)
3069                 goto free_cache;
3070 
3071         sdev->use_srq = true;
3072         sdev->srq = srq;
3073 
3074         for (i = 0; i < sdev->srq_size; ++i) {
3075                 INIT_LIST_HEAD(&sdev->ioctx_ring[i]->wait_list);
3076                 srpt_post_recv(sdev, NULL, sdev->ioctx_ring[i]);
3077         }
3078 
3079         return 0;
3080 
3081 free_cache:
3082         kmem_cache_destroy(sdev->req_buf_cache);
3083 
3084 free_srq:
3085         ib_destroy_srq(srq);
3086         return -ENOMEM;
3087 }
3088 
3089 static int srpt_use_srq(struct srpt_device *sdev, bool use_srq)
3090 {
3091         struct ib_device *device = sdev->device;
3092         int ret = 0;
3093 
3094         if (!use_srq) {
3095                 srpt_free_srq(sdev);
3096                 sdev->use_srq = false;
3097         } else if (use_srq && !sdev->srq) {
3098                 ret = srpt_alloc_srq(sdev);
3099         }
3100         pr_debug("%s(%s): use_srq = %d; ret = %d\n", __func__,
3101                  dev_name(&device->dev), sdev->use_srq, ret);
3102         return ret;
3103 }
3104 
3105 /**
3106  * srpt_add_one - InfiniBand device addition callback function
3107  * @device: Describes a HCA.
3108  */
3109 static void srpt_add_one(struct ib_device *device)
3110 {
3111         struct srpt_device *sdev;
3112         struct srpt_port *sport;
3113         int i, ret;
3114 
3115         pr_debug("device = %p\n", device);
3116 
3117         sdev = kzalloc(struct_size(sdev, port, device->phys_port_cnt),
3118                        GFP_KERNEL);
3119         if (!sdev)
3120                 goto err;
3121 
3122         sdev->device = device;
3123         mutex_init(&sdev->sdev_mutex);
3124 
3125         sdev->pd = ib_alloc_pd(device, 0);
3126         if (IS_ERR(sdev->pd))
3127                 goto free_dev;
3128 
3129         sdev->lkey = sdev->pd->local_dma_lkey;
3130 
3131         sdev->srq_size = min(srpt_srq_size, sdev->device->attrs.max_srq_wr);
3132 
3133         srpt_use_srq(sdev, sdev->port[0].port_attrib.use_srq);
3134 
3135         if (!srpt_service_guid)
3136                 srpt_service_guid = be64_to_cpu(device->node_guid);
3137 
3138         if (rdma_port_get_link_layer(device, 1) == IB_LINK_LAYER_INFINIBAND)
3139                 sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
3140         if (IS_ERR(sdev->cm_id)) {
3141                 pr_info("ib_create_cm_id() failed: %ld\n",
3142                         PTR_ERR(sdev->cm_id));
3143                 sdev->cm_id = NULL;
3144                 if (!rdma_cm_id)
3145                         goto err_ring;
3146         }
3147 
3148         /* print out target login information */
3149         pr_debug("Target login info: id_ext=%016llx,ioc_guid=%016llx,pkey=ffff,service_id=%016llx\n",
3150                  srpt_service_guid, srpt_service_guid, srpt_service_guid);
3151 
3152         /*
3153          * We do not have a consistent service_id (ie. also id_ext of target_id)
3154          * to identify this target. We currently use the guid of the first HCA
3155          * in the system as service_id; therefore, the target_id will change
3156          * if this HCA is gone bad and replaced by different HCA
3157          */
3158         ret = sdev->cm_id ?
3159                 ib_cm_listen(sdev->cm_id, cpu_to_be64(srpt_service_guid), 0) :
3160                 0;
3161         if (ret < 0) {
3162                 pr_err("ib_cm_listen() failed: %d (cm_id state = %d)\n", ret,
3163                        sdev->cm_id->state);
3164                 goto err_cm;
3165         }
3166 
3167         INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
3168                               srpt_event_handler);
3169         ib_register_event_handler(&sdev->event_handler);
3170 
3171         for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
3172                 sport = &sdev->port[i - 1];
3173                 INIT_LIST_HEAD(&sport->nexus_list);
3174                 init_waitqueue_head(&sport->ch_releaseQ);
3175                 mutex_init(&sport->mutex);
3176                 sport->sdev = sdev;
3177                 sport->port = i;
3178                 sport->port_attrib.srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
3179                 sport->port_attrib.srp_max_rsp_size = DEFAULT_MAX_RSP_SIZE;
3180                 sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
3181                 sport->port_attrib.use_srq = false;
3182                 INIT_WORK(&sport->work, srpt_refresh_port_work);
3183 
3184                 if (srpt_refresh_port(sport)) {
3185                         pr_err("MAD registration failed for %s-%d.\n",
3186                                dev_name(&sdev->device->dev), i);
3187                         goto err_event;
3188                 }
3189         }
3190 
3191         spin_lock(&srpt_dev_lock);
3192         list_add_tail(&sdev->list, &srpt_dev_list);
3193         spin_unlock(&srpt_dev_lock);
3194 
3195 out:
3196         ib_set_client_data(device, &srpt_client, sdev);
3197         pr_debug("added %s.\n", dev_name(&device->dev));
3198         return;
3199 
3200 err_event:
3201         ib_unregister_event_handler(&sdev->event_handler);
3202 err_cm:
3203         if (sdev->cm_id)
3204                 ib_destroy_cm_id(sdev->cm_id);
3205 err_ring:
3206         srpt_free_srq(sdev);
3207         ib_dealloc_pd(sdev->pd);
3208 free_dev:
3209         kfree(sdev);
3210 err:
3211         sdev = NULL;
3212         pr_info("%s(%s) failed.\n", __func__, dev_name(&device->dev));
3213         goto out;
3214 }
3215 
3216 /**
3217  * srpt_remove_one - InfiniBand device removal callback function
3218  * @device: Describes a HCA.
3219  * @client_data: The value passed as the third argument to ib_set_client_data().
3220  */
3221 static void srpt_remove_one(struct ib_device *device, void *client_data)
3222 {
3223         struct srpt_device *sdev = client_data;
3224         int i;
3225 
3226         if (!sdev) {
3227                 pr_info("%s(%s): nothing to do.\n", __func__,
3228                         dev_name(&device->dev));
3229                 return;
3230         }
3231 
3232         srpt_unregister_mad_agent(sdev);
3233 
3234         ib_unregister_event_handler(&sdev->event_handler);
3235 
3236         /* Cancel any work queued by the just unregistered IB event handler. */
3237         for (i = 0; i < sdev->device->phys_port_cnt; i++)
3238                 cancel_work_sync(&sdev->port[i].work);
3239 
3240         if (sdev->cm_id)
3241                 ib_destroy_cm_id(sdev->cm_id);
3242 
3243         ib_set_client_data(device, &srpt_client, NULL);
3244 
3245         /*
3246          * Unregistering a target must happen after destroying sdev->cm_id
3247          * such that no new SRP_LOGIN_REQ information units can arrive while
3248          * destroying the target.
3249          */
3250         spin_lock(&srpt_dev_lock);
3251         list_del(&sdev->list);
3252         spin_unlock(&srpt_dev_lock);
3253 
3254         for (i = 0; i < sdev->device->phys_port_cnt; i++)
3255                 srpt_release_sport(&sdev->port[i]);
3256 
3257         srpt_free_srq(sdev);
3258 
3259         ib_dealloc_pd(sdev->pd);
3260 
3261         kfree(sdev);
3262 }
3263 
3264 static struct ib_client srpt_client = {
3265         .name = DRV_NAME,
3266         .add = srpt_add_one,
3267         .remove = srpt_remove_one
3268 };
3269 
3270 static int srpt_check_true(struct se_portal_group *se_tpg)
3271 {
3272         return 1;
3273 }
3274 
3275 static int srpt_check_false(struct se_portal_group *se_tpg)
3276 {
3277         return 0;
3278 }
3279 
3280 static struct srpt_port *srpt_tpg_to_sport(struct se_portal_group *tpg)
3281 {
3282         return tpg->se_tpg_wwn->priv;
3283 }
3284 
3285 static char *srpt_get_fabric_wwn(struct se_portal_group *tpg)
3286 {
3287         struct srpt_port *sport = srpt_tpg_to_sport(tpg);
3288 
3289         WARN_ON_ONCE(tpg != &sport->port_guid_tpg &&
3290                      tpg != &sport->port_gid_tpg);
3291         return tpg == &sport->port_guid_tpg ? sport->port_guid :
3292                 sport->port_gid;
3293 }
3294 
3295 static u16 srpt_get_tag(struct se_portal_group *tpg)
3296 {
3297         return 1;
3298 }
3299 
3300 static u32 srpt_tpg_get_inst_index(struct se_portal_group *se_tpg)
3301 {
3302         return 1;
3303 }
3304 
3305 static void srpt_release_cmd(struct se_cmd *se_cmd)
3306 {
3307         struct srpt_send_ioctx *ioctx = container_of(se_cmd,
3308                                 struct srpt_send_ioctx, cmd);
3309         struct srpt_rdma_ch *ch = ioctx->ch;
3310         struct srpt_recv_ioctx *recv_ioctx = ioctx->recv_ioctx;
3311 
3312         WARN_ON_ONCE(ioctx->state != SRPT_STATE_DONE &&
3313                      !(ioctx->cmd.transport_state & CMD_T_ABORTED));
3314 
3315         if (recv_ioctx) {
3316                 WARN_ON_ONCE(!list_empty(&recv_ioctx->wait_list));
3317                 ioctx->recv_ioctx = NULL;
3318                 srpt_post_recv(ch->sport->sdev, ch, recv_ioctx);
3319         }
3320 
3321         if (ioctx->n_rw_ctx) {
3322                 srpt_free_rw_ctxs(ch, ioctx);
3323                 ioctx->n_rw_ctx = 0;
3324         }
3325 
3326         target_free_tag(se_cmd->se_sess, se_cmd);
3327 }
3328 
3329 /**
3330  * srpt_close_session - forcibly close a session
3331  * @se_sess: SCSI target session.
3332  *
3333  * Callback function invoked by the TCM core to clean up sessions associated
3334  * with a node ACL when the user invokes
3335  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3336  */
3337 static void srpt_close_session(struct se_session *se_sess)
3338 {
3339         struct srpt_rdma_ch *ch = se_sess->fabric_sess_ptr;
3340 
3341         srpt_disconnect_ch_sync(ch);
3342 }
3343 
3344 /**
3345  * srpt_sess_get_index - return the value of scsiAttIntrPortIndex (SCSI-MIB)
3346  * @se_sess: SCSI target session.
3347  *
3348  * A quote from RFC 4455 (SCSI-MIB) about this MIB object:
3349  * This object represents an arbitrary integer used to uniquely identify a
3350  * particular attached remote initiator port to a particular SCSI target port
3351  * within a particular SCSI target device within a particular SCSI instance.
3352  */
3353 static u32 srpt_sess_get_index(struct se_session *se_sess)
3354 {
3355         return 0;
3356 }
3357 
3358 static void srpt_set_default_node_attrs(struct se_node_acl *nacl)
3359 {
3360 }
3361 
3362 /* Note: only used from inside debug printk's by the TCM core. */
3363 static int srpt_get_tcm_cmd_state(struct se_cmd *se_cmd)
3364 {
3365         struct srpt_send_ioctx *ioctx;
3366 
3367         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3368         return ioctx->state;
3369 }
3370 
3371 static int srpt_parse_guid(u64 *guid, const char *name)
3372 {
3373         u16 w[4];
3374         int ret = -EINVAL;
3375 
3376         if (sscanf(name, "%hx:%hx:%hx:%hx", &w[0], &w[1], &w[2], &w[3]) != 4)
3377                 goto out;
3378         *guid = get_unaligned_be64(w);
3379         ret = 0;
3380 out:
3381         return ret;
3382 }
3383 
3384 /**
3385  * srpt_parse_i_port_id - parse an initiator port ID
3386  * @name: ASCII representation of a 128-bit initiator port ID.
3387  * @i_port_id: Binary 128-bit port ID.
3388  */
3389 static int srpt_parse_i_port_id(u8 i_port_id[16], const char *name)
3390 {
3391         const char *p;
3392         unsigned len, count, leading_zero_bytes;
3393         int ret;
3394 
3395         p = name;
3396         if (strncasecmp(p, "0x", 2) == 0)
3397                 p += 2;
3398         ret = -EINVAL;
3399         len = strlen(p);
3400         if (len % 2)
3401                 goto out;
3402         count = min(len / 2, 16U);
3403         leading_zero_bytes = 16 - count;
3404         memset(i_port_id, 0, leading_zero_bytes);
3405         ret = hex2bin(i_port_id + leading_zero_bytes, p, count);
3406 
3407 out:
3408         return ret;
3409 }
3410 
3411 /*
3412  * configfs callback function invoked for mkdir
3413  * /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3414  *
3415  * i_port_id must be an initiator port GUID, GID or IP address. See also the
3416  * target_alloc_session() calls in this driver. Examples of valid initiator
3417  * port IDs:
3418  * 0x0000000000000000505400fffe4a0b7b
3419  * 0000000000000000505400fffe4a0b7b
3420  * 5054:00ff:fe4a:0b7b
3421  * 192.168.122.76
3422  */
3423 static int srpt_init_nodeacl(struct se_node_acl *se_nacl, const char *name)
3424 {
3425         struct sockaddr_storage sa;
3426         u64 guid;
3427         u8 i_port_id[16];
3428         int ret;
3429 
3430         ret = srpt_parse_guid(&guid, name);
3431         if (ret < 0)
3432                 ret = srpt_parse_i_port_id(i_port_id, name);
3433         if (ret < 0)
3434                 ret = inet_pton_with_scope(&init_net, AF_UNSPEC, name, NULL,
3435                                            &sa);
3436         if (ret < 0)
3437                 pr_err("invalid initiator port ID %s\n", name);
3438         return ret;
3439 }
3440 
3441 static ssize_t srpt_tpg_attrib_srp_max_rdma_size_show(struct config_item *item,
3442                 char *page)
3443 {
3444         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3445         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3446 
3447         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rdma_size);
3448 }
3449 
3450 static ssize_t srpt_tpg_attrib_srp_max_rdma_size_store(struct config_item *item,
3451                 const char *page, size_t count)
3452 {
3453         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3454         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3455         unsigned long val;
3456         int ret;
3457 
3458         ret = kstrtoul(page, 0, &val);
3459         if (ret < 0) {
3460                 pr_err("kstrtoul() failed with ret: %d\n", ret);
3461                 return -EINVAL;
3462         }
3463         if (val > MAX_SRPT_RDMA_SIZE) {
3464                 pr_err("val: %lu exceeds MAX_SRPT_RDMA_SIZE: %d\n", val,
3465                         MAX_SRPT_RDMA_SIZE);
3466                 return -EINVAL;
3467         }
3468         if (val < DEFAULT_MAX_RDMA_SIZE) {
3469                 pr_err("val: %lu smaller than DEFAULT_MAX_RDMA_SIZE: %d\n",
3470                         val, DEFAULT_MAX_RDMA_SIZE);
3471                 return -EINVAL;
3472         }
3473         sport->port_attrib.srp_max_rdma_size = val;
3474 
3475         return count;
3476 }
3477 
3478 static ssize_t srpt_tpg_attrib_srp_max_rsp_size_show(struct config_item *item,
3479                 char *page)
3480 {
3481         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3482         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3483 
3484         return sprintf(page, "%u\n", sport->port_attrib.srp_max_rsp_size);
3485 }
3486 
3487 static ssize_t srpt_tpg_attrib_srp_max_rsp_size_store(struct config_item *item,
3488                 const char *page, size_t count)
3489 {
3490         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3491         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3492         unsigned long val;
3493         int ret;
3494 
3495         ret = kstrtoul(page, 0, &val);
3496         if (ret < 0) {
3497                 pr_err("kstrtoul() failed with ret: %d\n", ret);
3498                 return -EINVAL;
3499         }
3500         if (val > MAX_SRPT_RSP_SIZE) {
3501                 pr_err("val: %lu exceeds MAX_SRPT_RSP_SIZE: %d\n", val,
3502                         MAX_SRPT_RSP_SIZE);
3503                 return -EINVAL;
3504         }
3505         if (val < MIN_MAX_RSP_SIZE) {
3506                 pr_err("val: %lu smaller than MIN_MAX_RSP_SIZE: %d\n", val,
3507                         MIN_MAX_RSP_SIZE);
3508                 return -EINVAL;
3509         }
3510         sport->port_attrib.srp_max_rsp_size = val;
3511 
3512         return count;
3513 }
3514 
3515 static ssize_t srpt_tpg_attrib_srp_sq_size_show(struct config_item *item,
3516                 char *page)
3517 {
3518         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3519         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3520 
3521         return sprintf(page, "%u\n", sport->port_attrib.srp_sq_size);
3522 }
3523 
3524 static ssize_t srpt_tpg_attrib_srp_sq_size_store(struct config_item *item,
3525                 const char *page, size_t count)
3526 {
3527         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3528         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3529         unsigned long val;
3530         int ret;
3531 
3532         ret = kstrtoul(page, 0, &val);
3533         if (ret < 0) {
3534                 pr_err("kstrtoul() failed with ret: %d\n", ret);
3535                 return -EINVAL;
3536         }
3537         if (val > MAX_SRPT_SRQ_SIZE) {
3538                 pr_err("val: %lu exceeds MAX_SRPT_SRQ_SIZE: %d\n", val,
3539                         MAX_SRPT_SRQ_SIZE);
3540                 return -EINVAL;
3541         }
3542         if (val < MIN_SRPT_SRQ_SIZE) {
3543                 pr_err("val: %lu smaller than MIN_SRPT_SRQ_SIZE: %d\n", val,
3544                         MIN_SRPT_SRQ_SIZE);
3545                 return -EINVAL;
3546         }
3547         sport->port_attrib.srp_sq_size = val;
3548 
3549         return count;
3550 }
3551 
3552 static ssize_t srpt_tpg_attrib_use_srq_show(struct config_item *item,
3553                                             char *page)
3554 {
3555         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3556         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3557 
3558         return sprintf(page, "%d\n", sport->port_attrib.use_srq);
3559 }
3560 
3561 static ssize_t srpt_tpg_attrib_use_srq_store(struct config_item *item,
3562                                              const char *page, size_t count)
3563 {
3564         struct se_portal_group *se_tpg = attrib_to_tpg(item);
3565         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3566         struct srpt_device *sdev = sport->sdev;
3567         unsigned long val;
3568         bool enabled;
3569         int ret;
3570 
3571         ret = kstrtoul(page, 0, &val);
3572         if (ret < 0)
3573                 return ret;
3574         if (val != !!val)
3575                 return -EINVAL;
3576 
3577         ret = mutex_lock_interruptible(&sdev->sdev_mutex);
3578         if (ret < 0)
3579                 return ret;
3580         ret = mutex_lock_interruptible(&sport->mutex);
3581         if (ret < 0)
3582                 goto unlock_sdev;
3583         enabled = sport->enabled;
3584         /* Log out all initiator systems before changing 'use_srq'. */
3585         srpt_set_enabled(sport, false);
3586         sport->port_attrib.use_srq = val;
3587         srpt_use_srq(sdev, sport->port_attrib.use_srq);
3588         srpt_set_enabled(sport, enabled);
3589         ret = count;
3590         mutex_unlock(&sport->mutex);
3591 unlock_sdev:
3592         mutex_unlock(&sdev->sdev_mutex);
3593 
3594         return ret;
3595 }
3596 
3597 CONFIGFS_ATTR(srpt_tpg_attrib_,  srp_max_rdma_size);
3598 CONFIGFS_ATTR(srpt_tpg_attrib_,  srp_max_rsp_size);
3599 CONFIGFS_ATTR(srpt_tpg_attrib_,  srp_sq_size);
3600 CONFIGFS_ATTR(srpt_tpg_attrib_,  use_srq);
3601 
3602 static struct configfs_attribute *srpt_tpg_attrib_attrs[] = {
3603         &srpt_tpg_attrib_attr_srp_max_rdma_size,
3604         &srpt_tpg_attrib_attr_srp_max_rsp_size,
3605         &srpt_tpg_attrib_attr_srp_sq_size,
3606         &srpt_tpg_attrib_attr_use_srq,
3607         NULL,
3608 };
3609 
3610 static struct rdma_cm_id *srpt_create_rdma_id(struct sockaddr *listen_addr)
3611 {
3612         struct rdma_cm_id *rdma_cm_id;
3613         int ret;
3614 
3615         rdma_cm_id = rdma_create_id(&init_net, srpt_rdma_cm_handler,
3616                                     NULL, RDMA_PS_TCP, IB_QPT_RC);
3617         if (IS_ERR(rdma_cm_id)) {
3618                 pr_err("RDMA/CM ID creation failed: %ld\n",
3619                        PTR_ERR(rdma_cm_id));
3620                 goto out;
3621         }
3622 
3623         ret = rdma_bind_addr(rdma_cm_id, listen_addr);
3624         if (ret) {
3625                 char addr_str[64];
3626 
3627                 snprintf(addr_str, sizeof(addr_str), "%pISp", listen_addr);
3628                 pr_err("Binding RDMA/CM ID to address %s failed: %d\n",
3629                        addr_str, ret);
3630                 rdma_destroy_id(rdma_cm_id);
3631                 rdma_cm_id = ERR_PTR(ret);
3632                 goto out;
3633         }
3634 
3635         ret = rdma_listen(rdma_cm_id, 128);
3636         if (ret) {
3637                 pr_err("rdma_listen() failed: %d\n", ret);
3638                 rdma_destroy_id(rdma_cm_id);
3639                 rdma_cm_id = ERR_PTR(ret);
3640         }
3641 
3642 out:
3643         return rdma_cm_id;
3644 }
3645 
3646 static ssize_t srpt_rdma_cm_port_show(struct config_item *item, char *page)
3647 {
3648         return sprintf(page, "%d\n", rdma_cm_port);
3649 }
3650 
3651 static ssize_t srpt_rdma_cm_port_store(struct config_item *item,
3652                                        const char *page, size_t count)
3653 {
3654         struct sockaddr_in  addr4 = { .sin_family  = AF_INET  };
3655         struct sockaddr_in6 addr6 = { .sin6_family = AF_INET6 };
3656         struct rdma_cm_id *new_id = NULL;
3657         u16 val;
3658         int ret;
3659 
3660         ret = kstrtou16(page, 0, &val);
3661         if (ret < 0)
3662                 return ret;
3663         ret = count;
3664         if (rdma_cm_port == val)
3665                 goto out;
3666 
3667         if (val) {
3668                 addr6.sin6_port = cpu_to_be16(val);
3669                 new_id = srpt_create_rdma_id((struct sockaddr *)&addr6);
3670                 if (IS_ERR(new_id)) {
3671                         addr4.sin_port = cpu_to_be16(val);
3672                         new_id = srpt_create_rdma_id((struct sockaddr *)&addr4);
3673                         if (IS_ERR(new_id)) {
3674                                 ret = PTR_ERR(new_id);
3675                                 goto out;
3676                         }
3677                 }
3678         }
3679 
3680         mutex_lock(&rdma_cm_mutex);
3681         rdma_cm_port = val;
3682         swap(rdma_cm_id, new_id);
3683         mutex_unlock(&rdma_cm_mutex);
3684 
3685         if (new_id)
3686                 rdma_destroy_id(new_id);
3687         ret = count;
3688 out:
3689         return ret;
3690 }
3691 
3692 CONFIGFS_ATTR(srpt_, rdma_cm_port);
3693 
3694 static struct configfs_attribute *srpt_da_attrs[] = {
3695         &srpt_attr_rdma_cm_port,
3696         NULL,
3697 };
3698 
3699 static ssize_t srpt_tpg_enable_show(struct config_item *item, char *page)
3700 {
3701         struct se_portal_group *se_tpg = to_tpg(item);
3702         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3703 
3704         return snprintf(page, PAGE_SIZE, "%d\n", sport->enabled);
3705 }
3706 
3707 static ssize_t srpt_tpg_enable_store(struct config_item *item,
3708                 const char *page, size_t count)
3709 {
3710         struct se_portal_group *se_tpg = to_tpg(item);
3711         struct srpt_port *sport = srpt_tpg_to_sport(se_tpg);
3712         unsigned long tmp;
3713         int ret;
3714 
3715         ret = kstrtoul(page, 0, &tmp);
3716         if (ret < 0) {
3717                 pr_err("Unable to extract srpt_tpg_store_enable\n");
3718                 return -EINVAL;
3719         }
3720 
3721         if ((tmp != 0) && (tmp != 1)) {
3722                 pr_err("Illegal value for srpt_tpg_store_enable: %lu\n", tmp);
3723                 return -EINVAL;
3724         }
3725 
3726         mutex_lock(&sport->mutex);
3727         srpt_set_enabled(sport, tmp);
3728         mutex_unlock(&sport->mutex);
3729 
3730         return count;
3731 }
3732 
3733 CONFIGFS_ATTR(srpt_tpg_, enable);
3734 
3735 static struct configfs_attribute *srpt_tpg_attrs[] = {
3736         &srpt_tpg_attr_enable,
3737         NULL,
3738 };
3739 
3740 /**
3741  * srpt_make_tpg - configfs callback invoked for mkdir /sys/kernel/config/target/$driver/$port/$tpg
3742  * @wwn: Corresponds to $driver/$port.
3743  * @name: $tpg.
3744  */
3745 static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
3746                                              const char *name)
3747 {
3748         struct srpt_port *sport = wwn->priv;
3749         struct se_portal_group *tpg;
3750         int res;
3751 
3752         WARN_ON_ONCE(wwn != &sport->port_guid_wwn &&
3753                      wwn != &sport->port_gid_wwn);
3754         tpg = wwn == &sport->port_guid_wwn ? &sport->port_guid_tpg :
3755                 &sport->port_gid_tpg;
3756         res = core_tpg_register(wwn, tpg, SCSI_PROTOCOL_SRP);
3757         if (res)
3758                 return ERR_PTR(res);
3759 
3760         return tpg;
3761 }
3762 
3763 /**
3764  * srpt_drop_tpg - configfs callback invoked for rmdir /sys/kernel/config/target/$driver/$port/$tpg
3765  * @tpg: Target portal group to deregister.
3766  */
3767 static void srpt_drop_tpg(struct se_portal_group *tpg)
3768 {
3769         struct srpt_port *sport = srpt_tpg_to_sport(tpg);
3770 
3771         sport->enabled = false;
3772         core_tpg_deregister(tpg);
3773 }
3774 
3775 /**
3776  * srpt_make_tport - configfs callback invoked for mkdir /sys/kernel/config/target/$driver/$port
3777  * @tf: Not used.
3778  * @group: Not used.
3779  * @name: $port.
3780  */
3781 static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf,
3782                                       struct config_group *group,
3783                                       const char *name)
3784 {
3785         return srpt_lookup_wwn(name) ? : ERR_PTR(-EINVAL);
3786 }
3787 
3788 /**
3789  * srpt_drop_tport - configfs callback invoked for rmdir /sys/kernel/config/target/$driver/$port
3790  * @wwn: $port.
3791  */
3792 static void srpt_drop_tport(struct se_wwn *wwn)
3793 {
3794 }
3795 
3796 static ssize_t srpt_wwn_version_show(struct config_item *item, char *buf)
3797 {
3798         return scnprintf(buf, PAGE_SIZE, "\n");
3799 }
3800 
3801 CONFIGFS_ATTR_RO(srpt_wwn_, version);
3802 
3803 static struct configfs_attribute *srpt_wwn_attrs[] = {
3804         &srpt_wwn_attr_version,
3805         NULL,
3806 };
3807 
3808 static const struct target_core_fabric_ops srpt_template = {
3809         .module                         = THIS_MODULE,
3810         .fabric_name                    = "srpt",
3811         .tpg_get_wwn                    = srpt_get_fabric_wwn,
3812         .tpg_get_tag                    = srpt_get_tag,
3813         .tpg_check_demo_mode            = srpt_check_false,
3814         .tpg_check_demo_mode_cache      = srpt_check_true,
3815         .tpg_check_demo_mode_write_protect = srpt_check_true,
3816         .tpg_check_prod_mode_write_protect = srpt_check_false,
3817         .tpg_get_inst_index             = srpt_tpg_get_inst_index,
3818         .release_cmd                    = srpt_release_cmd,
3819         .check_stop_free                = srpt_check_stop_free,
3820         .close_session                  = srpt_close_session,
3821         .sess_get_index                 = srpt_sess_get_index,
3822         .sess_get_initiator_sid         = NULL,
3823         .write_pending                  = srpt_write_pending,
3824         .set_default_node_attributes    = srpt_set_default_node_attrs,
3825         .get_cmd_state                  = srpt_get_tcm_cmd_state,
3826         .queue_data_in                  = srpt_queue_data_in,
3827         .queue_status                   = srpt_queue_status,
3828         .queue_tm_rsp                   = srpt_queue_tm_rsp,
3829         .aborted_task                   = srpt_aborted_task,
3830         /*
3831          * Setup function pointers for generic logic in
3832          * target_core_fabric_configfs.c
3833          */
3834         .fabric_make_wwn                = srpt_make_tport,
3835         .fabric_drop_wwn                = srpt_drop_tport,
3836         .fabric_make_tpg                = srpt_make_tpg,
3837         .fabric_drop_tpg                = srpt_drop_tpg,
3838         .fabric_init_nodeacl            = srpt_init_nodeacl,
3839 
3840         .tfc_discovery_attrs            = srpt_da_attrs,
3841         .tfc_wwn_attrs                  = srpt_wwn_attrs,
3842         .tfc_tpg_base_attrs             = srpt_tpg_attrs,
3843         .tfc_tpg_attrib_attrs           = srpt_tpg_attrib_attrs,
3844 };
3845 
3846 /**
3847  * srpt_init_module - kernel module initialization
3848  *
3849  * Note: Since ib_register_client() registers callback functions, and since at
3850  * least one of these callback functions (srpt_add_one()) calls target core
3851  * functions, this driver must be registered with the target core before
3852  * ib_register_client() is called.
3853  */
3854 static int __init srpt_init_module(void)
3855 {
3856         int ret;
3857 
3858         ret = -EINVAL;
3859         if (srp_max_req_size < MIN_MAX_REQ_SIZE) {
3860                 pr_err("invalid value %d for kernel module parameter srp_max_req_size -- must be at least %d.\n",
3861                        srp_max_req_size, MIN_MAX_REQ_SIZE);
3862                 goto out;
3863         }
3864 
3865         if (srpt_srq_size < MIN_SRPT_SRQ_SIZE
3866             || srpt_srq_size > MAX_SRPT_SRQ_SIZE) {
3867                 pr_err("invalid value %d for kernel module parameter srpt_srq_size -- must be in the range [%d..%d].\n",
3868                        srpt_srq_size, MIN_SRPT_SRQ_SIZE, MAX_SRPT_SRQ_SIZE);
3869                 goto out;
3870         }
3871 
3872         ret = target_register_template(&srpt_template);
3873         if (ret)
3874                 goto out;
3875 
3876         ret = ib_register_client(&srpt_client);
3877         if (ret) {
3878                 pr_err("couldn't register IB client\n");
3879                 goto out_unregister_target;
3880         }
3881 
3882         return 0;
3883 
3884 out_unregister_target:
3885         target_unregister_template(&srpt_template);
3886 out:
3887         return ret;
3888 }
3889 
3890 static void __exit srpt_cleanup_module(void)
3891 {
3892         if (rdma_cm_id)
3893                 rdma_destroy_id(rdma_cm_id);
3894         ib_unregister_client(&srpt_client);
3895         target_unregister_template(&srpt_template);
3896 }
3897 
3898 module_init(srpt_init_module);
3899 module_exit(srpt_cleanup_module);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/infiniband/ulp/srpt/ib_srpt.c

DEFINITIONS
