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