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