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 <linux/percpu_ida.h>
  32 #include <asm/unaligned.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/libfc.h>
  35 #include <scsi/fc_encode.h>
  36
  37 #include <target/target_core_base.h>
  38 #include <target/target_core_fabric.h>
  39
  40 #include "tcm_fc.h"
  41
  42 /*
  43  * Dump cmd state for debugging.
  44  */
  45 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  46 {
  47         struct fc_exch *ep;
  48         struct fc_seq *sp;
  49         struct se_cmd *se_cmd;
  50         struct scatterlist *sg;
  51         int count;
  52
  53         se_cmd = &cmd->se_cmd;
  54         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  55                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  56
  57         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  58                 caller, cmd, se_cmd->t_data_nents,
  59                se_cmd->data_length, se_cmd->se_cmd_flags);
  60
  61         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  62                 pr_debug("%s: cmd %p sg %p page %p "
  63                         "len 0x%x off 0x%x\n",
  64                         caller, cmd, sg,
  65                         sg_page(sg), sg->length, sg->offset);
  66
  67         sp = cmd->seq;
  68         if (sp) {
  69                 ep = fc_seq_exch(sp);
  70                 pr_debug("%s: cmd %p sid %x did %x "
  71                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  72                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  73                         sp->id, ep->esb_stat);
  74         }
  75 }
  76
  77 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  78 {
  79         if (unlikely(ft_debug_logging))
  80                 _ft_dump_cmd(cmd, caller);
  81 }
  82
  83 static void ft_free_cmd(struct ft_cmd *cmd)
  84 {
  85         struct fc_frame *fp;
  86         struct fc_lport *lport;
  87         struct ft_sess *sess;
  88
  89         if (!cmd)
  90                 return;
  91         sess = cmd->sess;
  92         fp = cmd->req_frame;
  93         lport = fr_dev(fp);
  94         if (fr_seq(fp))
  95                 fc_seq_release(fr_seq(fp));
  96         fc_frame_free(fp);
  97         percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
  98         ft_sess_put(sess);      /* undo get from lookup at recv */
  99 }
 100
 101 void ft_release_cmd(struct se_cmd *se_cmd)
 102 {
 103         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 104
 105         ft_free_cmd(cmd);
 106 }
 107
 108 int ft_check_stop_free(struct se_cmd *se_cmd)
 109 {
 110         return transport_generic_free_cmd(se_cmd, 0);
 111 }
 112
 113 /*
 114  * Send response.
 115  */
 116 int ft_queue_status(struct se_cmd *se_cmd)
 117 {
 118         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 119         struct fc_frame *fp;
 120         struct fcp_resp_with_ext *fcp;
 121         struct fc_lport *lport;
 122         struct fc_exch *ep;
 123         size_t len;
 124         int rc;
 125
 126         if (cmd->aborted)
 127                 return 0;
 128         ft_dump_cmd(cmd, __func__);
 129         ep = fc_seq_exch(cmd->seq);
 130         lport = ep->lp;
 131         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 132         fp = fc_frame_alloc(lport, len);
 133         if (!fp) {
 134                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 135                 return -ENOMEM;
 136         }
 137
 138         fcp = fc_frame_payload_get(fp, len);
 139         memset(fcp, 0, len);
 140         fcp->resp.fr_status = se_cmd->scsi_status;
 141
 142         len = se_cmd->scsi_sense_length;
 143         if (len) {
 144                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 145                 fcp->ext.fr_sns_len = htonl(len);
 146                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 147         }
 148
 149         /*
 150          * Test underflow and overflow with one mask.  Usually both are off.
 151          * Bidirectional commands are not handled yet.
 152          */
 153         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 154                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 155                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 156                 else
 157                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 158                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 159         }
 160
 161         /*
 162          * Send response.
 163          */
 164         cmd->seq = fc_seq_start_next(cmd->seq);
 165         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 166                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 167
 168         rc = fc_seq_send(lport, cmd->seq, fp);
 169         if (rc) {
 170                 pr_info_ratelimited("%s: Failed to send response frame %p, "
 171                                     "xid <0x%x>\n", __func__, fp, ep->xid);
 172                 /*
 173                  * Generate a TASK_SET_FULL status to notify the initiator
 174                  * to reduce it's queue_depth after the se_cmd response has
 175                  * been re-queued by target-core.
 176                  */
 177                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 178                 return -ENOMEM;
 179         }
 180         fc_exch_done(cmd->seq);
 181         /*
 182          * Drop the extra ACK_KREF reference taken by target_submit_cmd()
 183          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 184          * final se_cmd->cmd_kref put.
 185          */
 186         target_put_sess_cmd(&cmd->se_cmd);
 187         return 0;
 188 }
 189
 190 int ft_write_pending_status(struct se_cmd *se_cmd)
 191 {
 192         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 193
 194         return cmd->write_data_len != se_cmd->data_length;
 195 }
 196
 197 /*
 198  * Send TX_RDY (transfer ready).
 199  */
 200 int ft_write_pending(struct se_cmd *se_cmd)
 201 {
 202         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 203         struct fc_frame *fp;
 204         struct fcp_txrdy *txrdy;
 205         struct fc_lport *lport;
 206         struct fc_exch *ep;
 207         struct fc_frame_header *fh;
 208         u32 f_ctl;
 209
 210         ft_dump_cmd(cmd, __func__);
 211
 212         if (cmd->aborted)
 213                 return 0;
 214         ep = fc_seq_exch(cmd->seq);
 215         lport = ep->lp;
 216         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 217         if (!fp)
 218                 return -ENOMEM; /* Signal QUEUE_FULL */
 219
 220         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 221         memset(txrdy, 0, sizeof(*txrdy));
 222         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 223
 224         cmd->seq = fc_seq_start_next(cmd->seq);
 225         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 226                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 227
 228         fh = fc_frame_header_get(fp);
 229         f_ctl = ntoh24(fh->fh_f_ctl);
 230
 231         /* Only if it is 'Exchange Responder' */
 232         if (f_ctl & FC_FC_EX_CTX) {
 233                 /* Target is 'exchange responder' and sending XFER_READY
 234                  * to 'exchange initiator (initiator)'
 235                  */
 236                 if ((ep->xid <= lport->lro_xid) &&
 237                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 238                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
 239                             lport->tt.ddp_target(lport, ep->xid,
 240                                                  se_cmd->t_data_sg,
 241                                                  se_cmd->t_data_nents))
 242                                 cmd->was_ddp_setup = 1;
 243                 }
 244         }
 245         fc_seq_send(lport, cmd->seq, fp);
 246         return 0;
 247 }
 248
 249 int ft_get_cmd_state(struct se_cmd *se_cmd)
 250 {
 251         return 0;
 252 }
 253
 254 /*
 255  * FC sequence response handler for follow-on sequences (data) and aborts.
 256  */
 257 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 258 {
 259         struct ft_cmd *cmd = arg;
 260         struct fc_frame_header *fh;
 261
 262         if (IS_ERR(fp)) {
 263                 /* XXX need to find cmd if queued */
 264                 cmd->seq = NULL;
 265                 cmd->aborted = true;
 266                 return;
 267         }
 268
 269         fh = fc_frame_header_get(fp);
 270
 271         switch (fh->fh_r_ctl) {
 272         case FC_RCTL_DD_SOL_DATA:       /* write data */
 273                 ft_recv_write_data(cmd, fp);
 274                 break;
 275         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 276         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 277         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 278         default:
 279                 pr_debug("%s: unhandled frame r_ctl %x\n",
 280                        __func__, fh->fh_r_ctl);
 281                 ft_invl_hw_context(cmd);
 282                 fc_frame_free(fp);
 283                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 284                 break;
 285         }
 286 }
 287
 288 /*
 289  * Send a FCP response including SCSI status and optional FCP rsp_code.
 290  * status is SAM_STAT_GOOD (zero) iff code is valid.
 291  * This is used in error cases, such as allocation failures.
 292  */
 293 static void ft_send_resp_status(struct fc_lport *lport,
 294                                 const struct fc_frame *rx_fp,
 295                                 u32 status, enum fcp_resp_rsp_codes code)
 296 {
 297         struct fc_frame *fp;
 298         struct fc_seq *sp;
 299         const struct fc_frame_header *fh;
 300         size_t len;
 301         struct fcp_resp_with_ext *fcp;
 302         struct fcp_resp_rsp_info *info;
 303
 304         fh = fc_frame_header_get(rx_fp);
 305         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 306                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 307         len = sizeof(*fcp);
 308         if (status == SAM_STAT_GOOD)
 309                 len += sizeof(*info);
 310         fp = fc_frame_alloc(lport, len);
 311         if (!fp)
 312                 return;
 313         fcp = fc_frame_payload_get(fp, len);
 314         memset(fcp, 0, len);
 315         fcp->resp.fr_status = status;
 316         if (status == SAM_STAT_GOOD) {
 317                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 318                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 319                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 320                 info->rsp_code = code;
 321         }
 322
 323         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 324         sp = fr_seq(fp);
 325         if (sp) {
 326                 fc_seq_send(lport, sp, fp);
 327                 fc_exch_done(sp);
 328         } else {
 329                 lport->tt.frame_send(lport, fp);
 330         }
 331 }
 332
 333 /*
 334  * Send error or task management response.
 335  */
 336 static void ft_send_resp_code(struct ft_cmd *cmd,
 337                               enum fcp_resp_rsp_codes code)
 338 {
 339         ft_send_resp_status(cmd->sess->tport->lport,
 340                             cmd->req_frame, SAM_STAT_GOOD, code);
 341 }
 342
 343
 344 /*
 345  * Send error or task management response.
 346  * Always frees the cmd and associated state.
 347  */
 348 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 349                                       enum fcp_resp_rsp_codes code)
 350 {
 351         ft_send_resp_code(cmd, code);
 352         ft_free_cmd(cmd);
 353 }
 354
 355 /*
 356  * Handle Task Management Request.
 357  */
 358 static void ft_send_tm(struct ft_cmd *cmd)
 359 {
 360         struct fcp_cmnd *fcp;
 361         int rc;
 362         u8 tm_func;
 363
 364         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 365
 366         switch (fcp->fc_tm_flags) {
 367         case FCP_TMF_LUN_RESET:
 368                 tm_func = TMR_LUN_RESET;
 369                 break;
 370         case FCP_TMF_TGT_RESET:
 371                 tm_func = TMR_TARGET_WARM_RESET;
 372                 break;
 373         case FCP_TMF_CLR_TASK_SET:
 374                 tm_func = TMR_CLEAR_TASK_SET;
 375                 break;
 376         case FCP_TMF_ABT_TASK_SET:
 377                 tm_func = TMR_ABORT_TASK_SET;
 378                 break;
 379         case FCP_TMF_CLR_ACA:
 380                 tm_func = TMR_CLEAR_ACA;
 381                 break;
 382         default:
 383                 /*
 384                  * FCP4r01 indicates having a combination of
 385                  * tm_flags set is invalid.
 386                  */
 387                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 388                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 389                 return;
 390         }
 391
 392         /* FIXME: Add referenced task tag for ABORT_TASK */
 393         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 394                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 395                 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
 396         if (rc < 0)
 397                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 398 }
 399
 400 /*
 401  * Send status from completed task management request.
 402  */
 403 void ft_queue_tm_resp(struct se_cmd *se_cmd)
 404 {
 405         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 406         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 407         enum fcp_resp_rsp_codes code;
 408
 409         if (cmd->aborted)
 410                 return;
 411         switch (tmr->response) {
 412         case TMR_FUNCTION_COMPLETE:
 413                 code = FCP_TMF_CMPL;
 414                 break;
 415         case TMR_LUN_DOES_NOT_EXIST:
 416                 code = FCP_TMF_INVALID_LUN;
 417                 break;
 418         case TMR_FUNCTION_REJECTED:
 419                 code = FCP_TMF_REJECTED;
 420                 break;
 421         case TMR_TASK_DOES_NOT_EXIST:
 422         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 423         default:
 424                 code = FCP_TMF_FAILED;
 425                 break;
 426         }
 427         pr_debug("tmr fn %d resp %d fcp code %d\n",
 428                   tmr->function, tmr->response, code);
 429         ft_send_resp_code(cmd, code);
 430         /*
 431          * Drop the extra ACK_KREF reference taken by target_submit_tmr()
 432          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 433          * final se_cmd->cmd_kref put.
 434          */
 435         target_put_sess_cmd(&cmd->se_cmd);
 436 }
 437
 438 void ft_aborted_task(struct se_cmd *se_cmd)
 439 {
 440         return;
 441 }
 442
 443 static void ft_send_work(struct work_struct *work);
 444
 445 /*
 446  * Handle incoming FCP command.
 447  */
 448 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 449 {
 450         struct ft_cmd *cmd;
 451         struct fc_lport *lport = sess->tport->lport;
 452         struct se_session *se_sess = sess->se_sess;
 453         int tag;
 454
 455         tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
 456         if (tag < 0)
 457                 goto busy;
 458
 459         cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
 460         memset(cmd, 0, sizeof(struct ft_cmd));
 461
 462         cmd->se_cmd.map_tag = tag;
 463         cmd->sess = sess;
 464         cmd->seq = fc_seq_assign(lport, fp);
 465         if (!cmd->seq) {
 466                 percpu_ida_free(&se_sess->sess_tag_pool, tag);
 467                 goto busy;
 468         }
 469         cmd->req_frame = fp;            /* hold frame during cmd */
 470
 471         INIT_WORK(&cmd->work, ft_send_work);
 472         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 473         return;
 474
 475 busy:
 476         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 477         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 478         fc_frame_free(fp);
 479         ft_sess_put(sess);              /* undo get from lookup */
 480 }
 481
 482
 483 /*
 484  * Handle incoming FCP frame.
 485  * Caller has verified that the frame is type FCP.
 486  */
 487 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 488 {
 489         struct fc_frame_header *fh = fc_frame_header_get(fp);
 490
 491         switch (fh->fh_r_ctl) {
 492         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 493                 ft_recv_cmd(sess, fp);
 494                 break;
 495         case FC_RCTL_DD_SOL_DATA:       /* write data */
 496         case FC_RCTL_DD_UNSOL_CTL:
 497         case FC_RCTL_DD_SOL_CTL:
 498         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 499         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 500         default:
 501                 pr_debug("%s: unhandled frame r_ctl %x\n",
 502                        __func__, fh->fh_r_ctl);
 503                 fc_frame_free(fp);
 504                 ft_sess_put(sess);      /* undo get from lookup */
 505                 break;
 506         }
 507 }
 508
 509 /*
 510  * Send new command to target.
 511  */
 512 static void ft_send_work(struct work_struct *work)
 513 {
 514         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 515         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 516         struct fcp_cmnd *fcp;
 517         int data_dir = 0;
 518         int task_attr;
 519
 520         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 521         if (!fcp)
 522                 goto err;
 523
 524         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 525                 goto err;               /* not handling longer CDBs yet */
 526
 527         /*
 528          * Check for FCP task management flags
 529          */
 530         if (fcp->fc_tm_flags) {
 531                 ft_send_tm(cmd);
 532                 return;
 533         }
 534
 535         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 536         case 0:
 537                 data_dir = DMA_NONE;
 538                 break;
 539         case FCP_CFL_RDDATA:
 540                 data_dir = DMA_FROM_DEVICE;
 541                 break;
 542         case FCP_CFL_WRDATA:
 543                 data_dir = DMA_TO_DEVICE;
 544                 break;
 545         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 546                 goto err;       /* TBD not supported by tcm_fc yet */
 547         }
 548         /*
 549          * Locate the SAM Task Attr from fc_pri_ta
 550          */
 551         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 552         case FCP_PTA_HEADQ:
 553                 task_attr = TCM_HEAD_TAG;
 554                 break;
 555         case FCP_PTA_ORDERED:
 556                 task_attr = TCM_ORDERED_TAG;
 557                 break;
 558         case FCP_PTA_ACA:
 559                 task_attr = TCM_ACA_TAG;
 560                 break;
 561         case FCP_PTA_SIMPLE: /* Fallthrough */
 562         default:
 563                 task_attr = TCM_SIMPLE_TAG;
 564         }
 565
 566         fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 567         cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
 568         /*
 569          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 570          * directly from ft_check_stop_free callback in response path.
 571          */
 572         if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 573                               &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 574                               ntohl(fcp->fc_dl), task_attr, data_dir,
 575                               TARGET_SCF_ACK_KREF | TARGET_SCF_USE_CPUID))
 576                 goto err;
 577
 578         pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
 579         return;
 580
 581 err:
 582         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 583 }