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 #include <target/target_core_configfs.h>
  40 #include <target/configfs_macros.h>
  41
  42 #include "tcm_fc.h"
  43
  44 /*
  45  * Dump cmd state for debugging.
  46  */
  47 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  48 {
  49         struct fc_exch *ep;
  50         struct fc_seq *sp;
  51         struct se_cmd *se_cmd;
  52         struct scatterlist *sg;
  53         int count;
  54
  55         se_cmd = &cmd->se_cmd;
  56         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  57                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  58
  59         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  60                 caller, cmd, se_cmd->t_data_nents,
  61                se_cmd->data_length, se_cmd->se_cmd_flags);
  62
  63         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  64                 pr_debug("%s: cmd %p sg %p page %p "
  65                         "len 0x%x off 0x%x\n",
  66                         caller, cmd, sg,
  67                         sg_page(sg), sg->length, sg->offset);
  68
  69         sp = cmd->seq;
  70         if (sp) {
  71                 ep = fc_seq_exch(sp);
  72                 pr_debug("%s: cmd %p sid %x did %x "
  73                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  74                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  75                         sp->id, ep->esb_stat);
  76         }
  77 }
  78
  79 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  80 {
  81         if (unlikely(ft_debug_logging))
  82                 _ft_dump_cmd(cmd, caller);
  83 }
  84
  85 static void ft_free_cmd(struct ft_cmd *cmd)
  86 {
  87         struct fc_frame *fp;
  88         struct fc_lport *lport;
  89         struct ft_sess *sess;
  90
  91         if (!cmd)
  92                 return;
  93         sess = cmd->sess;
  94         fp = cmd->req_frame;
  95         lport = fr_dev(fp);
  96         if (fr_seq(fp))
  97                 lport->tt.seq_release(fr_seq(fp));
  98         fc_frame_free(fp);
  99         percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
 100         ft_sess_put(sess);      /* undo get from lookup at recv */
 101 }
 102
 103 void ft_release_cmd(struct se_cmd *se_cmd)
 104 {
 105         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 106
 107         ft_free_cmd(cmd);
 108 }
 109
 110 int ft_check_stop_free(struct se_cmd *se_cmd)
 111 {
 112         transport_generic_free_cmd(se_cmd, 0);
 113         return 1;
 114 }
 115
 116 /*
 117  * Send response.
 118  */
 119 int ft_queue_status(struct se_cmd *se_cmd)
 120 {
 121         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 122         struct fc_frame *fp;
 123         struct fcp_resp_with_ext *fcp;
 124         struct fc_lport *lport;
 125         struct fc_exch *ep;
 126         size_t len;
 127         int rc;
 128
 129         if (cmd->aborted)
 130                 return 0;
 131         ft_dump_cmd(cmd, __func__);
 132         ep = fc_seq_exch(cmd->seq);
 133         lport = ep->lp;
 134         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 135         fp = fc_frame_alloc(lport, len);
 136         if (!fp) {
 137                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 138                 return -ENOMEM;
 139         }
 140
 141         fcp = fc_frame_payload_get(fp, len);
 142         memset(fcp, 0, len);
 143         fcp->resp.fr_status = se_cmd->scsi_status;
 144
 145         len = se_cmd->scsi_sense_length;
 146         if (len) {
 147                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 148                 fcp->ext.fr_sns_len = htonl(len);
 149                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 150         }
 151
 152         /*
 153          * Test underflow and overflow with one mask.  Usually both are off.
 154          * Bidirectional commands are not handled yet.
 155          */
 156         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 157                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 158                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 159                 else
 160                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 161                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 162         }
 163
 164         /*
 165          * Send response.
 166          */
 167         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 168         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 169                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 170
 171         rc = lport->tt.seq_send(lport, cmd->seq, fp);
 172         if (rc) {
 173                 pr_info_ratelimited("%s: Failed to send response frame %p, "
 174                                     "xid <0x%x>\n", __func__, fp, ep->xid);
 175                 /*
 176                  * Generate a TASK_SET_FULL status to notify the initiator
 177                  * to reduce it's queue_depth after the se_cmd response has
 178                  * been re-queued by target-core.
 179                  */
 180                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 181                 return -ENOMEM;
 182         }
 183         lport->tt.exch_done(cmd->seq);
 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 = lport->tt.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         lport->tt.seq_send(lport, cmd->seq, fp);
 243         return 0;
 244 }
 245
 246 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 247 {
 248         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 249
 250         if (cmd->aborted)
 251                 return ~0;
 252         return fc_seq_exch(cmd->seq)->rxid;
 253 }
 254
 255 int ft_get_cmd_state(struct se_cmd *se_cmd)
 256 {
 257         return 0;
 258 }
 259
 260 /*
 261  * FC sequence response handler for follow-on sequences (data) and aborts.
 262  */
 263 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 264 {
 265         struct ft_cmd *cmd = arg;
 266         struct fc_frame_header *fh;
 267
 268         if (unlikely(IS_ERR(fp))) {
 269                 /* XXX need to find cmd if queued */
 270                 cmd->seq = NULL;
 271                 cmd->aborted = true;
 272                 return;
 273         }
 274
 275         fh = fc_frame_header_get(fp);
 276
 277         switch (fh->fh_r_ctl) {
 278         case FC_RCTL_DD_SOL_DATA:       /* write data */
 279                 ft_recv_write_data(cmd, fp);
 280                 break;
 281         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 282         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 283         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 284         default:
 285                 pr_debug("%s: unhandled frame r_ctl %x\n",
 286                        __func__, fh->fh_r_ctl);
 287                 ft_invl_hw_context(cmd);
 288                 fc_frame_free(fp);
 289                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 290                 break;
 291         }
 292 }
 293
 294 /*
 295  * Send a FCP response including SCSI status and optional FCP rsp_code.
 296  * status is SAM_STAT_GOOD (zero) iff code is valid.
 297  * This is used in error cases, such as allocation failures.
 298  */
 299 static void ft_send_resp_status(struct fc_lport *lport,
 300                                 const struct fc_frame *rx_fp,
 301                                 u32 status, enum fcp_resp_rsp_codes code)
 302 {
 303         struct fc_frame *fp;
 304         struct fc_seq *sp;
 305         const struct fc_frame_header *fh;
 306         size_t len;
 307         struct fcp_resp_with_ext *fcp;
 308         struct fcp_resp_rsp_info *info;
 309
 310         fh = fc_frame_header_get(rx_fp);
 311         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 312                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 313         len = sizeof(*fcp);
 314         if (status == SAM_STAT_GOOD)
 315                 len += sizeof(*info);
 316         fp = fc_frame_alloc(lport, len);
 317         if (!fp)
 318                 return;
 319         fcp = fc_frame_payload_get(fp, len);
 320         memset(fcp, 0, len);
 321         fcp->resp.fr_status = status;
 322         if (status == SAM_STAT_GOOD) {
 323                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 324                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 325                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 326                 info->rsp_code = code;
 327         }
 328
 329         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 330         sp = fr_seq(fp);
 331         if (sp) {
 332                 lport->tt.seq_send(lport, sp, fp);
 333                 lport->tt.exch_done(sp);
 334         } else {
 335                 lport->tt.frame_send(lport, fp);
 336         }
 337 }
 338
 339 /*
 340  * Send error or task management response.
 341  */
 342 static void ft_send_resp_code(struct ft_cmd *cmd,
 343                               enum fcp_resp_rsp_codes code)
 344 {
 345         ft_send_resp_status(cmd->sess->tport->lport,
 346                             cmd->req_frame, SAM_STAT_GOOD, code);
 347 }
 348
 349
 350 /*
 351  * Send error or task management response.
 352  * Always frees the cmd and associated state.
 353  */
 354 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 355                                       enum fcp_resp_rsp_codes code)
 356 {
 357         ft_send_resp_code(cmd, code);
 358         ft_free_cmd(cmd);
 359 }
 360
 361 /*
 362  * Handle Task Management Request.
 363  */
 364 static void ft_send_tm(struct ft_cmd *cmd)
 365 {
 366         struct fcp_cmnd *fcp;
 367         int rc;
 368         u8 tm_func;
 369
 370         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 371
 372         switch (fcp->fc_tm_flags) {
 373         case FCP_TMF_LUN_RESET:
 374                 tm_func = TMR_LUN_RESET;
 375                 break;
 376         case FCP_TMF_TGT_RESET:
 377                 tm_func = TMR_TARGET_WARM_RESET;
 378                 break;
 379         case FCP_TMF_CLR_TASK_SET:
 380                 tm_func = TMR_CLEAR_TASK_SET;
 381                 break;
 382         case FCP_TMF_ABT_TASK_SET:
 383                 tm_func = TMR_ABORT_TASK_SET;
 384                 break;
 385         case FCP_TMF_CLR_ACA:
 386                 tm_func = TMR_CLEAR_ACA;
 387                 break;
 388         default:
 389                 /*
 390                  * FCP4r01 indicates having a combination of
 391                  * tm_flags set is invalid.
 392                  */
 393                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 394                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 395                 return;
 396         }
 397
 398         /* FIXME: Add referenced task tag for ABORT_TASK */
 399         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 400                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 401                 cmd, tm_func, GFP_KERNEL, 0, 0);
 402         if (rc < 0)
 403                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 404 }
 405
 406 /*
 407  * Send status from completed task management request.
 408  */
 409 void ft_queue_tm_resp(struct se_cmd *se_cmd)
 410 {
 411         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 412         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 413         enum fcp_resp_rsp_codes code;
 414
 415         if (cmd->aborted)
 416                 return;
 417         switch (tmr->response) {
 418         case TMR_FUNCTION_COMPLETE:
 419                 code = FCP_TMF_CMPL;
 420                 break;
 421         case TMR_LUN_DOES_NOT_EXIST:
 422                 code = FCP_TMF_INVALID_LUN;
 423                 break;
 424         case TMR_FUNCTION_REJECTED:
 425                 code = FCP_TMF_REJECTED;
 426                 break;
 427         case TMR_TASK_DOES_NOT_EXIST:
 428         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 429         default:
 430                 code = FCP_TMF_FAILED;
 431                 break;
 432         }
 433         pr_debug("tmr fn %d resp %d fcp code %d\n",
 434                   tmr->function, tmr->response, code);
 435         ft_send_resp_code(cmd, code);
 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 = lport->tt.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_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 567         /*
 568          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 569          * directly from ft_check_stop_free callback in response path.
 570          */
 571         if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 572                               &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 573                               ntohl(fcp->fc_dl), task_attr, data_dir, 0))
 574                 goto err;
 575
 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 }