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