drivers/target/tcm_fc/tfc_cmd.c

   1 /*
   2  * Copyright (c) 2010 Cisco Systems, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 /* XXX TBD some includes may be extraneous */
  19
  20 #include <linux/module.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/version.h>
  23 #include <generated/utsrelease.h>
  24 #include <linux/utsname.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/kthread.h>
  28 #include <linux/types.h>
  29 #include <linux/string.h>
  30 #include <linux/configfs.h>
  31 #include <linux/ctype.h>
  32 #include <linux/hash.h>
  33 #include <asm/unaligned.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/scsi_host.h>
  36 #include <scsi/scsi_device.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_tcq.h>
  39 #include <scsi/libfc.h>
  40 #include <scsi/fc_encode.h>
  41
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_transport.h>
  44 #include <target/target_core_fabric_ops.h>
  45 #include <target/target_core_device.h>
  46 #include <target/target_core_tpg.h>
  47 #include <target/target_core_configfs.h>
  48 #include <target/target_core_base.h>
  49 #include <target/target_core_tmr.h>
  50 #include <target/configfs_macros.h>
  51
  52 #include "tcm_fc.h"
  53
  54 /*
  55  * Dump cmd state for debugging.
  56  */
  57 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  58 {
  59         struct fc_exch *ep;
  60         struct fc_seq *sp;
  61         struct se_cmd *se_cmd;
  62         struct se_mem *mem;
  63
  64         if (!(ft_debug_logging & FT_DEBUG_IO))
  65                 return;
  66
  67         se_cmd = &cmd->se_cmd;
  68         printk(KERN_INFO "%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
  69                 caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
  70         printk(KERN_INFO "%s: cmd %p cdb %p\n",
  71                 caller, cmd, cmd->cdb);
  72         printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
  73
  74         printk(KERN_INFO "%s: cmd %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
  75                caller, cmd, se_cmd->t_tasks_se_num,
  76                se_cmd->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
  77
  78         list_for_each_entry(mem, &se_cmd->t_mem_list, se_list)
  79                 printk(KERN_INFO "%s: cmd %p mem %p page %p "
  80                        "len 0x%x off 0x%x\n",
  81                        caller, cmd, mem,
  82                        mem->se_page, mem->se_len, mem->se_off);
  83         sp = cmd->seq;
  84         if (sp) {
  85                 ep = fc_seq_exch(sp);
  86                 printk(KERN_INFO "%s: cmd %p sid %x did %x "
  87                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  88                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  89                         sp->id, ep->esb_stat);
  90         }
  91         print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
  92                 16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
  93 }
  94
  95 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
  96 {
  97         struct se_queue_obj *qobj;
  98         unsigned long flags;
  99
 100         qobj = &sess->tport->tpg->qobj;
 101         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 102         list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
 103         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 104         atomic_inc(&qobj->queue_cnt);
 105         wake_up_interruptible(&qobj->thread_wq);
 106 }
 107
 108 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
 109 {
 110         unsigned long flags;
 111         struct se_queue_req *qr;
 112
 113         spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
 114         if (list_empty(&qobj->qobj_list)) {
 115                 spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 116                 return NULL;
 117         }
 118         qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
 119         list_del(&qr->qr_list);
 120         atomic_dec(&qobj->queue_cnt);
 121         spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
 122         return container_of(qr, struct ft_cmd, se_req);
 123 }
 124
 125 static void ft_free_cmd(struct ft_cmd *cmd)
 126 {
 127         struct fc_frame *fp;
 128         struct fc_lport *lport;
 129
 130         if (!cmd)
 131                 return;
 132         fp = cmd->req_frame;
 133         lport = fr_dev(fp);
 134         if (fr_seq(fp))
 135                 lport->tt.seq_release(fr_seq(fp));
 136         fc_frame_free(fp);
 137         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 138         kfree(cmd);
 139 }
 140
 141 void ft_release_cmd(struct se_cmd *se_cmd)
 142 {
 143         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 144
 145         ft_free_cmd(cmd);
 146 }
 147
 148 void ft_check_stop_free(struct se_cmd *se_cmd)
 149 {
 150         transport_generic_free_cmd(se_cmd, 0, 0);
 151 }
 152
 153 /*
 154  * Send response.
 155  */
 156 int ft_queue_status(struct se_cmd *se_cmd)
 157 {
 158         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 159         struct fc_frame *fp;
 160         struct fcp_resp_with_ext *fcp;
 161         struct fc_lport *lport;
 162         struct fc_exch *ep;
 163         size_t len;
 164
 165         ft_dump_cmd(cmd, __func__);
 166         ep = fc_seq_exch(cmd->seq);
 167         lport = ep->lp;
 168         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 169         fp = fc_frame_alloc(lport, len);
 170         if (!fp) {
 171                 /* XXX shouldn't just drop it - requeue and retry? */
 172                 return 0;
 173         }
 174         fcp = fc_frame_payload_get(fp, len);
 175         memset(fcp, 0, len);
 176         fcp->resp.fr_status = se_cmd->scsi_status;
 177
 178         len = se_cmd->scsi_sense_length;
 179         if (len) {
 180                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 181                 fcp->ext.fr_sns_len = htonl(len);
 182                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 183         }
 184
 185         /*
 186          * Test underflow and overflow with one mask.  Usually both are off.
 187          * Bidirectional commands are not handled yet.
 188          */
 189         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 190                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 191                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 192                 else
 193                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 194                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 195         }
 196
 197         /*
 198          * Send response.
 199          */
 200         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 201         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 202                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 203
 204         lport->tt.seq_send(lport, cmd->seq, fp);
 205         lport->tt.exch_done(cmd->seq);
 206         return 0;
 207 }
 208
 209 int ft_write_pending_status(struct se_cmd *se_cmd)
 210 {
 211         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 212
 213         return cmd->write_data_len != se_cmd->data_length;
 214 }
 215
 216 /*
 217  * Send TX_RDY (transfer ready).
 218  */
 219 int ft_write_pending(struct se_cmd *se_cmd)
 220 {
 221         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 222         struct fc_frame *fp;
 223         struct fcp_txrdy *txrdy;
 224         struct fc_lport *lport;
 225         struct fc_exch *ep;
 226         struct fc_frame_header *fh;
 227         u32 f_ctl;
 228
 229         ft_dump_cmd(cmd, __func__);
 230
 231         ep = fc_seq_exch(cmd->seq);
 232         lport = ep->lp;
 233         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 234         if (!fp)
 235                 return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 236
 237         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 238         memset(txrdy, 0, sizeof(*txrdy));
 239         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 240
 241         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 242         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 243                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 244
 245         fh = fc_frame_header_get(fp);
 246         f_ctl = ntoh24(fh->fh_f_ctl);
 247
 248         /* Only if it is 'Exchange Responder' */
 249         if (f_ctl & FC_FC_EX_CTX) {
 250                 /* Target is 'exchange responder' and sending XFER_READY
 251                  * to 'exchange initiator (initiator)'
 252                  */
 253                 if ((ep->xid <= lport->lro_xid) &&
 254                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 255                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 256                                 /*
 257                                  * Map se_mem list to scatterlist, so that
 258                                  * DDP can be setup. DDP setup function require
 259                                  * scatterlist. se_mem_list is internal to
 260                                  * TCM/LIO target
 261                                  */
 262                                 transport_do_task_sg_chain(se_cmd);
 263                                 cmd->sg = se_cmd->t_tasks_sg_chained;
 264                                 cmd->sg_cnt =
 265                                         se_cmd->t_tasks_sg_chained_no;
 266                         }
 267                         if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
 268                                                     cmd->sg, cmd->sg_cnt))
 269                                 cmd->was_ddp_setup = 1;
 270                 }
 271         }
 272         lport->tt.seq_send(lport, cmd->seq, fp);
 273         return 0;
 274 }
 275
 276 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 277 {
 278         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 279
 280         return fc_seq_exch(cmd->seq)->rxid;
 281 }
 282
 283 int ft_get_cmd_state(struct se_cmd *se_cmd)
 284 {
 285         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 286
 287         return cmd->state;
 288 }
 289
 290 int ft_is_state_remove(struct se_cmd *se_cmd)
 291 {
 292         return 0;       /* XXX TBD */
 293 }
 294
 295 /*
 296  * FC sequence response handler for follow-on sequences (data) and aborts.
 297  */
 298 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 299 {
 300         struct ft_cmd *cmd = arg;
 301         struct fc_frame_header *fh;
 302
 303         if (IS_ERR(fp)) {
 304                 /* XXX need to find cmd if queued */
 305                 cmd->se_cmd.t_state = TRANSPORT_REMOVE;
 306                 cmd->seq = NULL;
 307                 transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 308                 return;
 309         }
 310
 311         fh = fc_frame_header_get(fp);
 312
 313         switch (fh->fh_r_ctl) {
 314         case FC_RCTL_DD_SOL_DATA:       /* write data */
 315                 ft_recv_write_data(cmd, fp);
 316                 break;
 317         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 318         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 319         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 320         default:
 321                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 322                        __func__, fh->fh_r_ctl);
 323                 fc_frame_free(fp);
 324                 transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 325                 break;
 326         }
 327 }
 328
 329 /*
 330  * Send a FCP response including SCSI status and optional FCP rsp_code.
 331  * status is SAM_STAT_GOOD (zero) iff code is valid.
 332  * This is used in error cases, such as allocation failures.
 333  */
 334 static void ft_send_resp_status(struct fc_lport *lport,
 335                                 const struct fc_frame *rx_fp,
 336                                 u32 status, enum fcp_resp_rsp_codes code)
 337 {
 338         struct fc_frame *fp;
 339         struct fc_seq *sp;
 340         const struct fc_frame_header *fh;
 341         size_t len;
 342         struct fcp_resp_with_ext *fcp;
 343         struct fcp_resp_rsp_info *info;
 344
 345         fh = fc_frame_header_get(rx_fp);
 346         FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
 347                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 348         len = sizeof(*fcp);
 349         if (status == SAM_STAT_GOOD)
 350                 len += sizeof(*info);
 351         fp = fc_frame_alloc(lport, len);
 352         if (!fp)
 353                 return;
 354         fcp = fc_frame_payload_get(fp, len);
 355         memset(fcp, 0, len);
 356         fcp->resp.fr_status = status;
 357         if (status == SAM_STAT_GOOD) {
 358                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 359                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 360                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 361                 info->rsp_code = code;
 362         }
 363
 364         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 365         sp = fr_seq(fp);
 366         if (sp)
 367                 lport->tt.seq_send(lport, sp, fp);
 368         else
 369                 lport->tt.frame_send(lport, fp);
 370 }
 371
 372 /*
 373  * Send error or task management response.
 374  * Always frees the cmd and associated state.
 375  */
 376 static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
 377 {
 378         ft_send_resp_status(cmd->sess->tport->lport,
 379                             cmd->req_frame, SAM_STAT_GOOD, code);
 380         ft_free_cmd(cmd);
 381 }
 382
 383 /*
 384  * Handle Task Management Request.
 385  */
 386 static void ft_send_tm(struct ft_cmd *cmd)
 387 {
 388         struct se_tmr_req *tmr;
 389         struct fcp_cmnd *fcp;
 390         struct ft_sess *sess;
 391         u8 tm_func;
 392
 393         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 394
 395         switch (fcp->fc_tm_flags) {
 396         case FCP_TMF_LUN_RESET:
 397                 tm_func = TMR_LUN_RESET;
 398                 break;
 399         case FCP_TMF_TGT_RESET:
 400                 tm_func = TMR_TARGET_WARM_RESET;
 401                 break;
 402         case FCP_TMF_CLR_TASK_SET:
 403                 tm_func = TMR_CLEAR_TASK_SET;
 404                 break;
 405         case FCP_TMF_ABT_TASK_SET:
 406                 tm_func = TMR_ABORT_TASK_SET;
 407                 break;
 408         case FCP_TMF_CLR_ACA:
 409                 tm_func = TMR_CLEAR_ACA;
 410                 break;
 411         default:
 412                 /*
 413                  * FCP4r01 indicates having a combination of
 414                  * tm_flags set is invalid.
 415                  */
 416                 FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 417                 ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 418                 return;
 419         }
 420
 421         FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
 422         tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
 423         if (!tmr) {
 424                 FT_TM_DBG("alloc failed\n");
 425                 ft_send_resp_code(cmd, FCP_TMF_FAILED);
 426                 return;
 427         }
 428         cmd->se_cmd.se_tmr_req = tmr;
 429
 430         switch (fcp->fc_tm_flags) {
 431         case FCP_TMF_LUN_RESET:
 432                 cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 433                 if (transport_lookup_tmr_lun(&cmd->se_cmd, cmd->lun) < 0) {
 434                         /*
 435                          * Make sure to clean up newly allocated TMR request
 436                          * since "unable to  handle TMR request because failed
 437                          * to get to LUN"
 438                          */
 439                         FT_TM_DBG("Failed to get LUN for TMR func %d, "
 440                                   "se_cmd %p, unpacked_lun %d\n",
 441                                   tm_func, &cmd->se_cmd, cmd->lun);
 442                         ft_dump_cmd(cmd, __func__);
 443                         sess = cmd->sess;
 444                         transport_send_check_condition_and_sense(&cmd->se_cmd,
 445                                 cmd->se_cmd.scsi_sense_reason, 0);
 446                         transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 447                         ft_sess_put(sess);
 448                         return;
 449                 }
 450                 break;
 451         case FCP_TMF_TGT_RESET:
 452         case FCP_TMF_CLR_TASK_SET:
 453         case FCP_TMF_ABT_TASK_SET:
 454         case FCP_TMF_CLR_ACA:
 455                 break;
 456         default:
 457                 return;
 458         }
 459         transport_generic_handle_tmr(&cmd->se_cmd);
 460 }
 461
 462 /*
 463  * Send status from completed task management request.
 464  */
 465 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 466 {
 467         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 468         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 469         enum fcp_resp_rsp_codes code;
 470
 471         switch (tmr->response) {
 472         case TMR_FUNCTION_COMPLETE:
 473                 code = FCP_TMF_CMPL;
 474                 break;
 475         case TMR_LUN_DOES_NOT_EXIST:
 476                 code = FCP_TMF_INVALID_LUN;
 477                 break;
 478         case TMR_FUNCTION_REJECTED:
 479                 code = FCP_TMF_REJECTED;
 480                 break;
 481         case TMR_TASK_DOES_NOT_EXIST:
 482         case TMR_TASK_STILL_ALLEGIANT:
 483         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 484         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 485         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 486         default:
 487                 code = FCP_TMF_FAILED;
 488                 break;
 489         }
 490         FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
 491                   tmr->function, tmr->response, code);
 492         ft_send_resp_code(cmd, code);
 493         return 0;
 494 }
 495
 496 /*
 497  * Handle incoming FCP command.
 498  */
 499 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 500 {
 501         struct ft_cmd *cmd;
 502         struct fc_lport *lport = sess->tport->lport;
 503
 504         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 505         if (!cmd)
 506                 goto busy;
 507         cmd->sess = sess;
 508         cmd->seq = lport->tt.seq_assign(lport, fp);
 509         if (!cmd->seq) {
 510                 kfree(cmd);
 511                 goto busy;
 512         }
 513         cmd->req_frame = fp;            /* hold frame during cmd */
 514         ft_queue_cmd(sess, cmd);
 515         return;
 516
 517 busy:
 518         FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
 519         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 520         fc_frame_free(fp);
 521         ft_sess_put(sess);              /* undo get from lookup */
 522 }
 523
 524
 525 /*
 526  * Handle incoming FCP frame.
 527  * Caller has verified that the frame is type FCP.
 528  */
 529 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 530 {
 531         struct fc_frame_header *fh = fc_frame_header_get(fp);
 532
 533         switch (fh->fh_r_ctl) {
 534         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 535                 ft_recv_cmd(sess, fp);
 536                 break;
 537         case FC_RCTL_DD_SOL_DATA:       /* write data */
 538         case FC_RCTL_DD_UNSOL_CTL:
 539         case FC_RCTL_DD_SOL_CTL:
 540         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 541         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 542         default:
 543                 printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
 544                        __func__, fh->fh_r_ctl);
 545                 fc_frame_free(fp);
 546                 ft_sess_put(sess);      /* undo get from lookup */
 547                 break;
 548         }
 549 }
 550
 551 /*
 552  * Send new command to target.
 553  */
 554 static void ft_send_cmd(struct ft_cmd *cmd)
 555 {
 556         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 557         struct se_cmd *se_cmd;
 558         struct fcp_cmnd *fcp;
 559         int data_dir;
 560         u32 data_len;
 561         int task_attr;
 562         int ret;
 563
 564         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 565         if (!fcp)
 566                 goto err;
 567
 568         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 569                 goto err;               /* not handling longer CDBs yet */
 570
 571         if (fcp->fc_tm_flags) {
 572                 task_attr = FCP_PTA_SIMPLE;
 573                 data_dir = DMA_NONE;
 574                 data_len = 0;
 575         } else {
 576                 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 577                 case 0:
 578                         data_dir = DMA_NONE;
 579                         break;
 580                 case FCP_CFL_RDDATA:
 581                         data_dir = DMA_FROM_DEVICE;
 582                         break;
 583                 case FCP_CFL_WRDATA:
 584                         data_dir = DMA_TO_DEVICE;
 585                         break;
 586                 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 587                         goto err;       /* TBD not supported by tcm_fc yet */
 588                 }
 589                 /*
 590                  * Locate the SAM Task Attr from fc_pri_ta
 591                  */
 592                 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 593                 case FCP_PTA_HEADQ:
 594                         task_attr = MSG_HEAD_TAG;
 595                         break;
 596                 case FCP_PTA_ORDERED:
 597                         task_attr = MSG_ORDERED_TAG;
 598                         break;
 599                 case FCP_PTA_ACA:
 600                         task_attr = MSG_ACA_TAG;
 601                         break;
 602                 case FCP_PTA_SIMPLE: /* Fallthrough */
 603                 default:
 604                         task_attr = MSG_SIMPLE_TAG;
 605                 }
 606
 607
 608                 task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
 609                 data_len = ntohl(fcp->fc_dl);
 610                 cmd->cdb = fcp->fc_cdb;
 611         }
 612
 613         se_cmd = &cmd->se_cmd;
 614         /*
 615          * Initialize struct se_cmd descriptor from target_core_mod
 616          * infrastructure
 617          */
 618         transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
 619                               data_len, data_dir, task_attr,
 620                               &cmd->ft_sense_buffer[0]);
 621         /*
 622          * Check for FCP task management flags
 623          */
 624         if (fcp->fc_tm_flags) {
 625                 ft_send_tm(cmd);
 626                 return;
 627         }
 628
 629         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 630
 631         cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
 632         ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
 633         if (ret < 0) {
 634                 ft_dump_cmd(cmd, __func__);
 635                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 636                         cmd->se_cmd.scsi_sense_reason, 0);
 637                 return;
 638         }
 639
 640         ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
 641
 642         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
 643         ft_dump_cmd(cmd, __func__);
 644
 645         if (ret == -ENOMEM) {
 646                 transport_send_check_condition_and_sense(se_cmd,
 647                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 648                 transport_generic_free_cmd(se_cmd, 0, 0);
 649                 return;
 650         }
 651         if (ret == -EINVAL) {
 652                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
 653                         ft_queue_status(se_cmd);
 654                 else
 655                         transport_send_check_condition_and_sense(se_cmd,
 656                                         se_cmd->scsi_sense_reason, 0);
 657                 transport_generic_free_cmd(se_cmd, 0, 0);
 658                 return;
 659         }
 660         transport_generic_handle_cdb(se_cmd);
 661         return;
 662
 663 err:
 664         ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
 665 }
 666
 667 /*
 668  * Handle request in the command thread.
 669  */
 670 static void ft_exec_req(struct ft_cmd *cmd)
 671 {
 672         FT_IO_DBG("cmd state %x\n", cmd->state);
 673         switch (cmd->state) {
 674         case FC_CMD_ST_NEW:
 675                 ft_send_cmd(cmd);
 676                 break;
 677         default:
 678                 break;
 679         }
 680 }
 681
 682 /*
 683  * Processing thread.
 684  * Currently one thread per tpg.
 685  */
 686 int ft_thread(void *arg)
 687 {
 688         struct ft_tpg *tpg = arg;
 689         struct se_queue_obj *qobj = &tpg->qobj;
 690         struct ft_cmd *cmd;
 691         int ret;
 692
 693         set_user_nice(current, -20);
 694
 695         while (!kthread_should_stop()) {
 696                 ret = wait_event_interruptible(qobj->thread_wq,
 697                         atomic_read(&qobj->queue_cnt) || kthread_should_stop());
 698                 if (ret < 0 || kthread_should_stop())
 699                         goto out;
 700                 cmd = ft_dequeue_cmd(qobj);
 701                 if (cmd)
 702                         ft_exec_req(cmd);
 703         }
 704
 705 out:
 706         return 0;
 707 }