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