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.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 static 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 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  84 {
  85         if (unlikely(ft_debug_logging))
  86                 _ft_dump_cmd(cmd, caller);
  87 }
  88
  89 static void ft_free_cmd(struct ft_cmd *cmd)
  90 {
  91         struct fc_frame *fp;
  92         struct fc_lport *lport;
  93         struct se_session *se_sess;
  94
  95         if (!cmd)
  96                 return;
  97         se_sess = cmd->sess->se_sess;
  98         fp = cmd->req_frame;
  99         lport = fr_dev(fp);
 100         if (fr_seq(fp))
 101                 lport->tt.seq_release(fr_seq(fp));
 102         fc_frame_free(fp);
 103         percpu_ida_free(&se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
 104         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 105 }
 106
 107 void ft_release_cmd(struct se_cmd *se_cmd)
 108 {
 109         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 110
 111         ft_free_cmd(cmd);
 112 }
 113
 114 int ft_check_stop_free(struct se_cmd *se_cmd)
 115 {
 116         transport_generic_free_cmd(se_cmd, 0);
 117         return 1;
 118 }
 119
 120 /*
 121  * Send response.
 122  */
 123 int ft_queue_status(struct se_cmd *se_cmd)
 124 {
 125         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 126         struct fc_frame *fp;
 127         struct fcp_resp_with_ext *fcp;
 128         struct fc_lport *lport;
 129         struct fc_exch *ep;
 130         size_t len;
 131
 132         if (cmd->aborted)
 133                 return 0;
 134         ft_dump_cmd(cmd, __func__);
 135         ep = fc_seq_exch(cmd->seq);
 136         lport = ep->lp;
 137         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 138         fp = fc_frame_alloc(lport, len);
 139         if (!fp) {
 140                 /* XXX shouldn't just drop it - requeue and retry? */
 141                 return 0;
 142         }
 143         fcp = fc_frame_payload_get(fp, len);
 144         memset(fcp, 0, len);
 145         fcp->resp.fr_status = se_cmd->scsi_status;
 146
 147         len = se_cmd->scsi_sense_length;
 148         if (len) {
 149                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 150                 fcp->ext.fr_sns_len = htonl(len);
 151                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 152         }
 153
 154         /*
 155          * Test underflow and overflow with one mask.  Usually both are off.
 156          * Bidirectional commands are not handled yet.
 157          */
 158         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 159                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 160                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 161                 else
 162                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 163                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 164         }
 165
 166         /*
 167          * Send response.
 168          */
 169         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 170         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 171                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 172
 173         lport->tt.seq_send(lport, cmd->seq, fp);
 174         lport->tt.exch_done(cmd->seq);
 175         return 0;
 176 }
 177
 178 int ft_write_pending_status(struct se_cmd *se_cmd)
 179 {
 180         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 181
 182         return cmd->write_data_len != se_cmd->data_length;
 183 }
 184
 185 /*
 186  * Send TX_RDY (transfer ready).
 187  */
 188 int ft_write_pending(struct se_cmd *se_cmd)
 189 {
 190         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 191         struct fc_frame *fp;
 192         struct fcp_txrdy *txrdy;
 193         struct fc_lport *lport;
 194         struct fc_exch *ep;
 195         struct fc_frame_header *fh;
 196         u32 f_ctl;
 197
 198         ft_dump_cmd(cmd, __func__);
 199
 200         if (cmd->aborted)
 201                 return 0;
 202         ep = fc_seq_exch(cmd->seq);
 203         lport = ep->lp;
 204         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 205         if (!fp)
 206                 return -ENOMEM; /* Signal QUEUE_FULL */
 207
 208         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 209         memset(txrdy, 0, sizeof(*txrdy));
 210         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 211
 212         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 213         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 214                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 215
 216         fh = fc_frame_header_get(fp);
 217         f_ctl = ntoh24(fh->fh_f_ctl);
 218
 219         /* Only if it is 'Exchange Responder' */
 220         if (f_ctl & FC_FC_EX_CTX) {
 221                 /* Target is 'exchange responder' and sending XFER_READY
 222                  * to 'exchange initiator (initiator)'
 223                  */
 224                 if ((ep->xid <= lport->lro_xid) &&
 225                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 226                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
 227                             lport->tt.ddp_target(lport, ep->xid,
 228                                                  se_cmd->t_data_sg,
 229                                                  se_cmd->t_data_nents))
 230                                 cmd->was_ddp_setup = 1;
 231                 }
 232         }
 233         lport->tt.seq_send(lport, cmd->seq, fp);
 234         return 0;
 235 }
 236
 237 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 238 {
 239         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 240
 241         if (cmd->aborted)
 242                 return ~0;
 243         return fc_seq_exch(cmd->seq)->rxid;
 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 (unlikely(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                 lport->tt.seq_send(lport, sp, fp);
 324                 lport->tt.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, 0);
 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
 429 static void ft_send_work(struct work_struct *work);
 430
 431 /*
 432  * Handle incoming FCP command.
 433  */
 434 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 435 {
 436         struct ft_cmd *cmd;
 437         struct fc_lport *lport = sess->tport->lport;
 438         struct se_session *se_sess = sess->se_sess;
 439         int tag;
 440
 441         tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
 442         if (tag < 0)
 443                 goto busy;
 444
 445         cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
 446         memset(cmd, 0, sizeof(struct ft_cmd));
 447
 448         cmd->se_cmd.map_tag = tag;
 449         cmd->sess = sess;
 450         cmd->seq = lport->tt.seq_assign(lport, fp);
 451         if (!cmd->seq) {
 452                 percpu_ida_free(&se_sess->sess_tag_pool, tag);
 453                 goto busy;
 454         }
 455         cmd->req_frame = fp;            /* hold frame during cmd */
 456
 457         INIT_WORK(&cmd->work, ft_send_work);
 458         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 459         return;
 460
 461 busy:
 462         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 463         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 464         fc_frame_free(fp);
 465         ft_sess_put(sess);              /* undo get from lookup */
 466 }
 467
 468
 469 /*
 470  * Handle incoming FCP frame.
 471  * Caller has verified that the frame is type FCP.
 472  */
 473 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 474 {
 475         struct fc_frame_header *fh = fc_frame_header_get(fp);
 476
 477         switch (fh->fh_r_ctl) {
 478         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 479                 ft_recv_cmd(sess, fp);
 480                 break;
 481         case FC_RCTL_DD_SOL_DATA:       /* write data */
 482         case FC_RCTL_DD_UNSOL_CTL:
 483         case FC_RCTL_DD_SOL_CTL:
 484         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 485         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 486         default:
 487                 pr_debug("%s: unhandled frame r_ctl %x\n",
 488                        __func__, fh->fh_r_ctl);
 489                 fc_frame_free(fp);
 490                 ft_sess_put(sess);      /* undo get from lookup */
 491                 break;
 492         }
 493 }
 494
 495 /*
 496  * Send new command to target.
 497  */
 498 static void ft_send_work(struct work_struct *work)
 499 {
 500         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 501         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 502         struct fcp_cmnd *fcp;
 503         int data_dir = 0;
 504         int task_attr;
 505
 506         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 507         if (!fcp)
 508                 goto err;
 509
 510         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 511                 goto err;               /* not handling longer CDBs yet */
 512
 513         /*
 514          * Check for FCP task management flags
 515          */
 516         if (fcp->fc_tm_flags) {
 517                 ft_send_tm(cmd);
 518                 return;
 519         }
 520
 521         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 522         case 0:
 523                 data_dir = DMA_NONE;
 524                 break;
 525         case FCP_CFL_RDDATA:
 526                 data_dir = DMA_FROM_DEVICE;
 527                 break;
 528         case FCP_CFL_WRDATA:
 529                 data_dir = DMA_TO_DEVICE;
 530                 break;
 531         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 532                 goto err;       /* TBD not supported by tcm_fc yet */
 533         }
 534         /*
 535          * Locate the SAM Task Attr from fc_pri_ta
 536          */
 537         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 538         case FCP_PTA_HEADQ:
 539                 task_attr = MSG_HEAD_TAG;
 540                 break;
 541         case FCP_PTA_ORDERED:
 542                 task_attr = MSG_ORDERED_TAG;
 543                 break;
 544         case FCP_PTA_ACA:
 545                 task_attr = MSG_ACA_TAG;
 546                 break;
 547         case FCP_PTA_SIMPLE: /* Fallthrough */
 548         default:
 549                 task_attr = MSG_SIMPLE_TAG;
 550         }
 551
 552         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 553         /*
 554          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 555          * directly from ft_check_stop_free callback in response path.
 556          */
 557         if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 558                               &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 559                               ntohl(fcp->fc_dl), task_attr, data_dir, 0))
 560                 goto err;
 561
 562         pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
 563         return;
 564
 565 err:
 566         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 567 }