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 <generated/utsrelease.h>
  23 #include <linux/utsname.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/kthread.h>
  27 #include <linux/types.h>
  28 #include <linux/string.h>
  29 #include <linux/configfs.h>
  30 #include <linux/ctype.h>
  31 #include <linux/hash.h>
  32 #include <asm/unaligned.h>
  33 #include <scsi/scsi.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi_device.h>
  36 #include <scsi/scsi_cmnd.h>
  37 #include <scsi/scsi_tcq.h>
  38 #include <scsi/libfc.h>
  39 #include <scsi/fc_encode.h>
  40
  41 #include <target/target_core_base.h>
  42 #include <target/target_core_fabric.h>
  43 #include <target/target_core_configfs.h>
  44 #include <target/configfs_macros.h>
  45
  46 #include "tcm_fc.h"
  47
  48 /*
  49  * Dump cmd state for debugging.
  50  */
  51 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  52 {
  53         struct fc_exch *ep;
  54         struct fc_seq *sp;
  55         struct se_cmd *se_cmd;
  56         struct scatterlist *sg;
  57         int count;
  58
  59         se_cmd = &cmd->se_cmd;
  60         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  61                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  62
  63         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  64                 caller, cmd, se_cmd->t_data_nents,
  65                se_cmd->data_length, se_cmd->se_cmd_flags);
  66
  67         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  68                 pr_debug("%s: cmd %p sg %p page %p "
  69                         "len 0x%x off 0x%x\n",
  70                         caller, cmd, sg,
  71                         sg_page(sg), sg->length, sg->offset);
  72
  73         sp = cmd->seq;
  74         if (sp) {
  75                 ep = fc_seq_exch(sp);
  76                 pr_debug("%s: cmd %p sid %x did %x "
  77                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  78                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  79                         sp->id, ep->esb_stat);
  80         }
  81 }
  82
  83 static void ft_free_cmd(struct ft_cmd *cmd)
  84 {
  85         struct fc_frame *fp;
  86         struct fc_lport *lport;
  87
  88         if (!cmd)
  89                 return;
  90         fp = cmd->req_frame;
  91         lport = fr_dev(fp);
  92         if (fr_seq(fp))
  93                 lport->tt.seq_release(fr_seq(fp));
  94         fc_frame_free(fp);
  95         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
  96         kfree(cmd);
  97 }
  98
  99 void ft_release_cmd(struct se_cmd *se_cmd)
 100 {
 101         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 102
 103         ft_free_cmd(cmd);
 104 }
 105
 106 int ft_check_stop_free(struct se_cmd *se_cmd)
 107 {
 108         transport_generic_free_cmd(se_cmd, 0);
 109         return 1;
 110 }
 111
 112 /*
 113  * Send response.
 114  */
 115 int ft_queue_status(struct se_cmd *se_cmd)
 116 {
 117         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 118         struct fc_frame *fp;
 119         struct fcp_resp_with_ext *fcp;
 120         struct fc_lport *lport;
 121         struct fc_exch *ep;
 122         size_t len;
 123
 124         ft_dump_cmd(cmd, __func__);
 125         ep = fc_seq_exch(cmd->seq);
 126         lport = ep->lp;
 127         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 128         fp = fc_frame_alloc(lport, len);
 129         if (!fp) {
 130                 /* XXX shouldn't just drop it - requeue and retry? */
 131                 return 0;
 132         }
 133         fcp = fc_frame_payload_get(fp, len);
 134         memset(fcp, 0, len);
 135         fcp->resp.fr_status = se_cmd->scsi_status;
 136
 137         len = se_cmd->scsi_sense_length;
 138         if (len) {
 139                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 140                 fcp->ext.fr_sns_len = htonl(len);
 141                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 142         }
 143
 144         /*
 145          * Test underflow and overflow with one mask.  Usually both are off.
 146          * Bidirectional commands are not handled yet.
 147          */
 148         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 149                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 150                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 151                 else
 152                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 153                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 154         }
 155
 156         /*
 157          * Send response.
 158          */
 159         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 160         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 161                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 162
 163         lport->tt.seq_send(lport, cmd->seq, fp);
 164         lport->tt.exch_done(cmd->seq);
 165         return 0;
 166 }
 167
 168 int ft_write_pending_status(struct se_cmd *se_cmd)
 169 {
 170         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 171
 172         return cmd->write_data_len != se_cmd->data_length;
 173 }
 174
 175 /*
 176  * Send TX_RDY (transfer ready).
 177  */
 178 int ft_write_pending(struct se_cmd *se_cmd)
 179 {
 180         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 181         struct fc_frame *fp;
 182         struct fcp_txrdy *txrdy;
 183         struct fc_lport *lport;
 184         struct fc_exch *ep;
 185         struct fc_frame_header *fh;
 186         u32 f_ctl;
 187
 188         ft_dump_cmd(cmd, __func__);
 189
 190         ep = fc_seq_exch(cmd->seq);
 191         lport = ep->lp;
 192         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 193         if (!fp)
 194                 return -ENOMEM; /* Signal QUEUE_FULL */
 195
 196         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 197         memset(txrdy, 0, sizeof(*txrdy));
 198         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 199
 200         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 201         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 202                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 203
 204         fh = fc_frame_header_get(fp);
 205         f_ctl = ntoh24(fh->fh_f_ctl);
 206
 207         /* Only if it is 'Exchange Responder' */
 208         if (f_ctl & FC_FC_EX_CTX) {
 209                 /* Target is 'exchange responder' and sending XFER_READY
 210                  * to 'exchange initiator (initiator)'
 211                  */
 212                 if ((ep->xid <= lport->lro_xid) &&
 213                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 214                         if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
 215                                 /*
 216                                  * cmd may have been broken up into multiple
 217                                  * tasks. Link their sgs together so we can
 218                                  * operate on them all at once.
 219                                  */
 220                                 transport_do_task_sg_chain(se_cmd);
 221                                 cmd->sg = se_cmd->t_tasks_sg_chained;
 222                                 cmd->sg_cnt =
 223                                         se_cmd->t_tasks_sg_chained_no;
 224                         }
 225                         if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
 226                                                             cmd->sg,
 227                                                             cmd->sg_cnt))
 228                                 cmd->was_ddp_setup = 1;
 229                 }
 230         }
 231         lport->tt.seq_send(lport, cmd->seq, fp);
 232         return 0;
 233 }
 234
 235 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 236 {
 237         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 238
 239         return fc_seq_exch(cmd->seq)->rxid;
 240 }
 241
 242 int ft_get_cmd_state(struct se_cmd *se_cmd)
 243 {
 244         return 0;
 245 }
 246
 247 int ft_is_state_remove(struct se_cmd *se_cmd)
 248 {
 249         return 0;       /* XXX TBD */
 250 }
 251
 252 /*
 253  * FC sequence response handler for follow-on sequences (data) and aborts.
 254  */
 255 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 256 {
 257         struct ft_cmd *cmd = arg;
 258         struct fc_frame_header *fh;
 259
 260         if (IS_ERR(fp)) {
 261                 /* XXX need to find cmd if queued */
 262                 cmd->seq = NULL;
 263                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 264                 return;
 265         }
 266
 267         fh = fc_frame_header_get(fp);
 268
 269         switch (fh->fh_r_ctl) {
 270         case FC_RCTL_DD_SOL_DATA:       /* write data */
 271                 ft_recv_write_data(cmd, fp);
 272                 break;
 273         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 274         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 275         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 276         default:
 277                 pr_debug("%s: unhandled frame r_ctl %x\n",
 278                        __func__, fh->fh_r_ctl);
 279                 ft_invl_hw_context(cmd);
 280                 fc_frame_free(fp);
 281                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 282                 break;
 283         }
 284 }
 285
 286 /*
 287  * Send a FCP response including SCSI status and optional FCP rsp_code.
 288  * status is SAM_STAT_GOOD (zero) iff code is valid.
 289  * This is used in error cases, such as allocation failures.
 290  */
 291 static void ft_send_resp_status(struct fc_lport *lport,
 292                                 const struct fc_frame *rx_fp,
 293                                 u32 status, enum fcp_resp_rsp_codes code)
 294 {
 295         struct fc_frame *fp;
 296         struct fc_seq *sp;
 297         const struct fc_frame_header *fh;
 298         size_t len;
 299         struct fcp_resp_with_ext *fcp;
 300         struct fcp_resp_rsp_info *info;
 301
 302         fh = fc_frame_header_get(rx_fp);
 303         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 304                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 305         len = sizeof(*fcp);
 306         if (status == SAM_STAT_GOOD)
 307                 len += sizeof(*info);
 308         fp = fc_frame_alloc(lport, len);
 309         if (!fp)
 310                 return;
 311         fcp = fc_frame_payload_get(fp, len);
 312         memset(fcp, 0, len);
 313         fcp->resp.fr_status = status;
 314         if (status == SAM_STAT_GOOD) {
 315                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 316                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 317                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 318                 info->rsp_code = code;
 319         }
 320
 321         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 322         sp = fr_seq(fp);
 323         if (sp)
 324                 lport->tt.seq_send(lport, sp, fp);
 325         else
 326                 lport->tt.frame_send(lport, fp);
 327 }
 328
 329 /*
 330  * Send error or task management response.
 331  */
 332 static void ft_send_resp_code(struct ft_cmd *cmd,
 333                               enum fcp_resp_rsp_codes code)
 334 {
 335         ft_send_resp_status(cmd->sess->tport->lport,
 336                             cmd->req_frame, SAM_STAT_GOOD, code);
 337 }
 338
 339
 340 /*
 341  * Send error or task management response.
 342  * Always frees the cmd and associated state.
 343  */
 344 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 345                                       enum fcp_resp_rsp_codes code)
 346 {
 347         ft_send_resp_code(cmd, code);
 348         ft_free_cmd(cmd);
 349 }
 350
 351 /*
 352  * Handle Task Management Request.
 353  */
 354 static void ft_send_tm(struct ft_cmd *cmd)
 355 {
 356         struct fcp_cmnd *fcp;
 357         struct ft_sess *sess;
 358         int rc;
 359         u8 tm_func;
 360
 361         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 362
 363         switch (fcp->fc_tm_flags) {
 364         case FCP_TMF_LUN_RESET:
 365                 tm_func = TMR_LUN_RESET;
 366                 break;
 367         case FCP_TMF_TGT_RESET:
 368                 tm_func = TMR_TARGET_WARM_RESET;
 369                 break;
 370         case FCP_TMF_CLR_TASK_SET:
 371                 tm_func = TMR_CLEAR_TASK_SET;
 372                 break;
 373         case FCP_TMF_ABT_TASK_SET:
 374                 tm_func = TMR_ABORT_TASK_SET;
 375                 break;
 376         case FCP_TMF_CLR_ACA:
 377                 tm_func = TMR_CLEAR_ACA;
 378                 break;
 379         default:
 380                 /*
 381                  * FCP4r01 indicates having a combination of
 382                  * tm_flags set is invalid.
 383                  */
 384                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 385                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 386                 return;
 387         }
 388
 389         transport_init_se_cmd(&cmd->se_cmd, &ft_configfs->tf_ops,
 390                         cmd->sess->se_sess, 0, DMA_NONE, 0,
 391                         &cmd->ft_sense_buffer[0]);
 392         target_get_sess_cmd(cmd->sess->se_sess, &cmd->se_cmd, false);
 393
 394         pr_debug("alloc tm cmd fn %d\n", tm_func);
 395         rc = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func, GFP_KERNEL);
 396         if (rc < 0) {
 397                 pr_debug("alloc failed\n");
 398                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 399                 return;
 400         }
 401
 402         rc = transport_lookup_tmr_lun(&cmd->se_cmd, scsilun_to_int(&fcp->fc_lun));
 403         if (rc < 0) {
 404                 pr_debug("Failed to get LUN for TMR func %d, "
 405                           "se_cmd %p, unpacked_lun %d\n",
 406                           tm_func, &cmd->se_cmd, scsilun_to_int(&fcp->fc_lun));
 407                 ft_dump_cmd(cmd, __func__);
 408                 sess = cmd->sess;
 409                 transport_send_check_condition_and_sense(&cmd->se_cmd,
 410                         cmd->se_cmd.scsi_sense_reason, 0);
 411                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 412                 return;
 413         }
 414
 415         transport_generic_handle_tmr(&cmd->se_cmd);
 416 }
 417
 418 /*
 419  * Send status from completed task management request.
 420  */
 421 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 422 {
 423         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 424         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 425         enum fcp_resp_rsp_codes code;
 426
 427         switch (tmr->response) {
 428         case TMR_FUNCTION_COMPLETE:
 429                 code = FCP_TMF_CMPL;
 430                 break;
 431         case TMR_LUN_DOES_NOT_EXIST:
 432                 code = FCP_TMF_INVALID_LUN;
 433                 break;
 434         case TMR_FUNCTION_REJECTED:
 435                 code = FCP_TMF_REJECTED;
 436                 break;
 437         case TMR_TASK_DOES_NOT_EXIST:
 438         case TMR_TASK_STILL_ALLEGIANT:
 439         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 440         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 441         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 442         default:
 443                 code = FCP_TMF_FAILED;
 444                 break;
 445         }
 446         pr_debug("tmr fn %d resp %d fcp code %d\n",
 447                   tmr->function, tmr->response, code);
 448         ft_send_resp_code(cmd, code);
 449         return 0;
 450 }
 451
 452 static void ft_send_work(struct work_struct *work);
 453
 454 /*
 455  * Handle incoming FCP command.
 456  */
 457 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 458 {
 459         struct ft_cmd *cmd;
 460         struct fc_lport *lport = sess->tport->lport;
 461
 462         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 463         if (!cmd)
 464                 goto busy;
 465         cmd->sess = sess;
 466         cmd->seq = lport->tt.seq_assign(lport, fp);
 467         if (!cmd->seq) {
 468                 kfree(cmd);
 469                 goto busy;
 470         }
 471         cmd->req_frame = fp;            /* hold frame during cmd */
 472
 473         INIT_WORK(&cmd->work, ft_send_work);
 474         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 475         return;
 476
 477 busy:
 478         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 479         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 480         fc_frame_free(fp);
 481         ft_sess_put(sess);              /* undo get from lookup */
 482 }
 483
 484
 485 /*
 486  * Handle incoming FCP frame.
 487  * Caller has verified that the frame is type FCP.
 488  */
 489 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 490 {
 491         struct fc_frame_header *fh = fc_frame_header_get(fp);
 492
 493         switch (fh->fh_r_ctl) {
 494         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 495                 ft_recv_cmd(sess, fp);
 496                 break;
 497         case FC_RCTL_DD_SOL_DATA:       /* write data */
 498         case FC_RCTL_DD_UNSOL_CTL:
 499         case FC_RCTL_DD_SOL_CTL:
 500         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 501         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 502         default:
 503                 pr_debug("%s: unhandled frame r_ctl %x\n",
 504                        __func__, fh->fh_r_ctl);
 505                 fc_frame_free(fp);
 506                 ft_sess_put(sess);      /* undo get from lookup */
 507                 break;
 508         }
 509 }
 510
 511 /*
 512  * Send new command to target.
 513  */
 514 static void ft_send_work(struct work_struct *work)
 515 {
 516         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 517         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 518         struct fcp_cmnd *fcp;
 519         int data_dir = 0;
 520         int task_attr;
 521
 522         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 523         if (!fcp)
 524                 goto err;
 525
 526         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 527                 goto err;               /* not handling longer CDBs yet */
 528
 529         /*
 530          * Check for FCP task management flags
 531          */
 532         if (fcp->fc_tm_flags) {
 533                 ft_send_tm(cmd);
 534                 return;
 535         }
 536
 537         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 538         case 0:
 539                 data_dir = DMA_NONE;
 540                 break;
 541         case FCP_CFL_RDDATA:
 542                 data_dir = DMA_FROM_DEVICE;
 543                 break;
 544         case FCP_CFL_WRDATA:
 545                 data_dir = DMA_TO_DEVICE;
 546                 break;
 547         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 548                 goto err;       /* TBD not supported by tcm_fc yet */
 549         }
 550         /*
 551          * Locate the SAM Task Attr from fc_pri_ta
 552          */
 553         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 554         case FCP_PTA_HEADQ:
 555                 task_attr = MSG_HEAD_TAG;
 556                 break;
 557         case FCP_PTA_ORDERED:
 558                 task_attr = MSG_ORDERED_TAG;
 559                 break;
 560         case FCP_PTA_ACA:
 561                 task_attr = MSG_ACA_TAG;
 562                 break;
 563         case FCP_PTA_SIMPLE: /* Fallthrough */
 564         default:
 565                 task_attr = MSG_SIMPLE_TAG;
 566         }
 567
 568         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 569         /*
 570          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 571          * directly from ft_check_stop_free callback in response path.
 572          */
 573         target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 574                         &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 575                         ntohl(fcp->fc_dl), task_attr, data_dir, 0);
 576         pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
 577         return;
 578
 579 err:
 580         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 581 }