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 <asm/unaligned.h>
  32 #include <scsi/scsi_tcq.h>
  33 #include <scsi/libfc.h>
  34 #include <scsi/fc_encode.h>
  35
  36 #include <target/target_core_base.h>
  37 #include <target/target_core_fabric.h>
  38
  39 #include "tcm_fc.h"
  40
  41 /*
  42  * Dump cmd state for debugging.
  43  */
  44 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  45 {
  46         struct fc_exch *ep;
  47         struct fc_seq *sp;
  48         struct se_cmd *se_cmd;
  49         struct scatterlist *sg;
  50         int count;
  51
  52         se_cmd = &cmd->se_cmd;
  53         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  54                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  55
  56         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  57                 caller, cmd, se_cmd->t_data_nents,
  58                se_cmd->data_length, se_cmd->se_cmd_flags);
  59
  60         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  61                 pr_debug("%s: cmd %p sg %p page %p "
  62                         "len 0x%x off 0x%x\n",
  63                         caller, cmd, sg,
  64                         sg_page(sg), sg->length, sg->offset);
  65
  66         sp = cmd->seq;
  67         if (sp) {
  68                 ep = fc_seq_exch(sp);
  69                 pr_debug("%s: cmd %p sid %x did %x "
  70                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  71                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  72                         sp->id, ep->esb_stat);
  73         }
  74 }
  75
  76 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  77 {
  78         if (unlikely(ft_debug_logging))
  79                 _ft_dump_cmd(cmd, caller);
  80 }
  81
  82 static void ft_free_cmd(struct ft_cmd *cmd)
  83 {
  84         struct fc_frame *fp;
  85         struct ft_sess *sess;
  86
  87         if (!cmd)
  88                 return;
  89         sess = cmd->sess;
  90         fp = cmd->req_frame;
  91         if (fr_seq(fp))
  92                 fc_seq_release(fr_seq(fp));
  93         fc_frame_free(fp);
  94         target_free_tag(sess->se_sess, &cmd->se_cmd);
  95         ft_sess_put(sess);      /* undo get from lookup at recv */
  96 }
  97
  98 void ft_release_cmd(struct se_cmd *se_cmd)
  99 {
 100         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 101
 102         ft_free_cmd(cmd);
 103 }
 104
 105 int ft_check_stop_free(struct se_cmd *se_cmd)
 106 {
 107         return transport_generic_free_cmd(se_cmd, 0);
 108 }
 109
 110 /*
 111  * Send response.
 112  */
 113 int ft_queue_status(struct se_cmd *se_cmd)
 114 {
 115         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 116         struct fc_frame *fp;
 117         struct fcp_resp_with_ext *fcp;
 118         struct fc_lport *lport;
 119         struct fc_exch *ep;
 120         size_t len;
 121         int rc;
 122
 123         if (cmd->aborted)
 124                 return 0;
 125         ft_dump_cmd(cmd, __func__);
 126         ep = fc_seq_exch(cmd->seq);
 127         lport = ep->lp;
 128         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 129         fp = fc_frame_alloc(lport, len);
 130         if (!fp) {
 131                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 132                 return -ENOMEM;
 133         }
 134
 135         fcp = fc_frame_payload_get(fp, len);
 136         memset(fcp, 0, len);
 137         fcp->resp.fr_status = se_cmd->scsi_status;
 138
 139         len = se_cmd->scsi_sense_length;
 140         if (len) {
 141                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 142                 fcp->ext.fr_sns_len = htonl(len);
 143                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 144         }
 145
 146         /*
 147          * Test underflow and overflow with one mask.  Usually both are off.
 148          * Bidirectional commands are not handled yet.
 149          */
 150         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 151                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 152                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 153                 else
 154                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 155                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 156         }
 157
 158         /*
 159          * Send response.
 160          */
 161         cmd->seq = fc_seq_start_next(cmd->seq);
 162         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 163                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 164
 165         rc = fc_seq_send(lport, cmd->seq, fp);
 166         if (rc) {
 167                 pr_info_ratelimited("%s: Failed to send response frame %p, "
 168                                     "xid <0x%x>\n", __func__, fp, ep->xid);
 169                 /*
 170                  * Generate a TASK_SET_FULL status to notify the initiator
 171                  * to reduce it's queue_depth after the se_cmd response has
 172                  * been re-queued by target-core.
 173                  */
 174                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 175                 return -ENOMEM;
 176         }
 177         fc_exch_done(cmd->seq);
 178         /*
 179          * Drop the extra ACK_KREF reference taken by target_submit_cmd()
 180          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 181          * final se_cmd->cmd_kref put.
 182          */
 183         target_put_sess_cmd(&cmd->se_cmd);
 184         return 0;
 185 }
 186
 187 /*
 188  * Send TX_RDY (transfer ready).
 189  */
 190 int ft_write_pending(struct se_cmd *se_cmd)
 191 {
 192         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 193         struct fc_frame *fp;
 194         struct fcp_txrdy *txrdy;
 195         struct fc_lport *lport;
 196         struct fc_exch *ep;
 197         struct fc_frame_header *fh;
 198         u32 f_ctl;
 199
 200         ft_dump_cmd(cmd, __func__);
 201
 202         if (cmd->aborted)
 203                 return 0;
 204         ep = fc_seq_exch(cmd->seq);
 205         lport = ep->lp;
 206         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 207         if (!fp)
 208                 return -ENOMEM; /* Signal QUEUE_FULL */
 209
 210         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 211         memset(txrdy, 0, sizeof(*txrdy));
 212         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 213
 214         cmd->seq = fc_seq_start_next(cmd->seq);
 215         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 216                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 217
 218         fh = fc_frame_header_get(fp);
 219         f_ctl = ntoh24(fh->fh_f_ctl);
 220
 221         /* Only if it is 'Exchange Responder' */
 222         if (f_ctl & FC_FC_EX_CTX) {
 223                 /* Target is 'exchange responder' and sending XFER_READY
 224                  * to 'exchange initiator (initiator)'
 225                  */
 226                 if ((ep->xid <= lport->lro_xid) &&
 227                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 228                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
 229                             lport->tt.ddp_target(lport, ep->xid,
 230                                                  se_cmd->t_data_sg,
 231                                                  se_cmd->t_data_nents))
 232                                 cmd->was_ddp_setup = 1;
 233                 }
 234         }
 235         fc_seq_send(lport, cmd->seq, fp);
 236         return 0;
 237 }
 238
 239 int ft_get_cmd_state(struct se_cmd *se_cmd)
 240 {
 241         return 0;
 242 }
 243
 244 /*
 245  * FC sequence response handler for follow-on sequences (data) and aborts.
 246  */
 247 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 248 {
 249         struct ft_cmd *cmd = arg;
 250         struct fc_frame_header *fh;
 251
 252         if (IS_ERR(fp)) {
 253                 /* XXX need to find cmd if queued */
 254                 cmd->seq = NULL;
 255                 cmd->aborted = true;
 256                 return;
 257         }
 258
 259         fh = fc_frame_header_get(fp);
 260
 261         switch (fh->fh_r_ctl) {
 262         case FC_RCTL_DD_SOL_DATA:       /* write data */
 263                 ft_recv_write_data(cmd, fp);
 264                 break;
 265         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 266         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 267         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 268         default:
 269                 pr_debug("%s: unhandled frame r_ctl %x\n",
 270                        __func__, fh->fh_r_ctl);
 271                 ft_invl_hw_context(cmd);
 272                 fc_frame_free(fp);
 273                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 274                 break;
 275         }
 276 }
 277
 278 /*
 279  * Send a FCP response including SCSI status and optional FCP rsp_code.
 280  * status is SAM_STAT_GOOD (zero) iff code is valid.
 281  * This is used in error cases, such as allocation failures.
 282  */
 283 static void ft_send_resp_status(struct fc_lport *lport,
 284                                 const struct fc_frame *rx_fp,
 285                                 u32 status, enum fcp_resp_rsp_codes code)
 286 {
 287         struct fc_frame *fp;
 288         struct fc_seq *sp;
 289         const struct fc_frame_header *fh;
 290         size_t len;
 291         struct fcp_resp_with_ext *fcp;
 292         struct fcp_resp_rsp_info *info;
 293
 294         fh = fc_frame_header_get(rx_fp);
 295         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 296                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 297         len = sizeof(*fcp);
 298         if (status == SAM_STAT_GOOD)
 299                 len += sizeof(*info);
 300         fp = fc_frame_alloc(lport, len);
 301         if (!fp)
 302                 return;
 303         fcp = fc_frame_payload_get(fp, len);
 304         memset(fcp, 0, len);
 305         fcp->resp.fr_status = status;
 306         if (status == SAM_STAT_GOOD) {
 307                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 308                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 309                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 310                 info->rsp_code = code;
 311         }
 312
 313         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 314         sp = fr_seq(fp);
 315         if (sp) {
 316                 fc_seq_send(lport, sp, fp);
 317                 fc_exch_done(sp);
 318         } else {
 319                 lport->tt.frame_send(lport, fp);
 320         }
 321 }
 322
 323 /*
 324  * Send error or task management response.
 325  */
 326 static void ft_send_resp_code(struct ft_cmd *cmd,
 327                               enum fcp_resp_rsp_codes code)
 328 {
 329         ft_send_resp_status(cmd->sess->tport->lport,
 330                             cmd->req_frame, SAM_STAT_GOOD, code);
 331 }
 332
 333
 334 /*
 335  * Send error or task management response.
 336  * Always frees the cmd and associated state.
 337  */
 338 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 339                                       enum fcp_resp_rsp_codes code)
 340 {
 341         ft_send_resp_code(cmd, code);
 342         ft_free_cmd(cmd);
 343 }
 344
 345 /*
 346  * Handle Task Management Request.
 347  */
 348 static void ft_send_tm(struct ft_cmd *cmd)
 349 {
 350         struct fcp_cmnd *fcp;
 351         int rc;
 352         u8 tm_func;
 353
 354         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 355
 356         switch (fcp->fc_tm_flags) {
 357         case FCP_TMF_LUN_RESET:
 358                 tm_func = TMR_LUN_RESET;
 359                 break;
 360         case FCP_TMF_TGT_RESET:
 361                 tm_func = TMR_TARGET_WARM_RESET;
 362                 break;
 363         case FCP_TMF_CLR_TASK_SET:
 364                 tm_func = TMR_CLEAR_TASK_SET;
 365                 break;
 366         case FCP_TMF_ABT_TASK_SET:
 367                 tm_func = TMR_ABORT_TASK_SET;
 368                 break;
 369         case FCP_TMF_CLR_ACA:
 370                 tm_func = TMR_CLEAR_ACA;
 371                 break;
 372         default:
 373                 /*
 374                  * FCP4r01 indicates having a combination of
 375                  * tm_flags set is invalid.
 376                  */
 377                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 378                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 379                 return;
 380         }
 381
 382         /* FIXME: Add referenced task tag for ABORT_TASK */
 383         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 384                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 385                 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
 386         if (rc < 0)
 387                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 388 }
 389
 390 /*
 391  * Send status from completed task management request.
 392  */
 393 void ft_queue_tm_resp(struct se_cmd *se_cmd)
 394 {
 395         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 396         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 397         enum fcp_resp_rsp_codes code;
 398
 399         if (cmd->aborted)
 400                 return;
 401         switch (tmr->response) {
 402         case TMR_FUNCTION_COMPLETE:
 403                 code = FCP_TMF_CMPL;
 404                 break;
 405         case TMR_LUN_DOES_NOT_EXIST:
 406                 code = FCP_TMF_INVALID_LUN;
 407                 break;
 408         case TMR_FUNCTION_REJECTED:
 409                 code = FCP_TMF_REJECTED;
 410                 break;
 411         case TMR_TASK_DOES_NOT_EXIST:
 412         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 413         default:
 414                 code = FCP_TMF_FAILED;
 415                 break;
 416         }
 417         pr_debug("tmr fn %d resp %d fcp code %d\n",
 418                   tmr->function, tmr->response, code);
 419         ft_send_resp_code(cmd, code);
 420         /*
 421          * Drop the extra ACK_KREF reference taken by target_submit_tmr()
 422          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 423          * final se_cmd->cmd_kref put.
 424          */
 425         target_put_sess_cmd(&cmd->se_cmd);
 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, cpu;
 444
 445         tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
 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->se_cmd.map_cpu = cpu;
 454         cmd->sess = sess;
 455         cmd->seq = fc_seq_assign(lport, fp);
 456         if (!cmd->seq) {
 457                 target_free_tag(se_sess, &cmd->se_cmd);
 458                 goto busy;
 459         }
 460         cmd->req_frame = fp;            /* hold frame during cmd */
 461
 462         INIT_WORK(&cmd->work, ft_send_work);
 463         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 464         return;
 465
 466 busy:
 467         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 468         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 469         fc_frame_free(fp);
 470         ft_sess_put(sess);              /* undo get from lookup */
 471 }
 472
 473
 474 /*
 475  * Handle incoming FCP frame.
 476  * Caller has verified that the frame is type FCP.
 477  */
 478 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 479 {
 480         struct fc_frame_header *fh = fc_frame_header_get(fp);
 481
 482         switch (fh->fh_r_ctl) {
 483         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 484                 ft_recv_cmd(sess, fp);
 485                 break;
 486         case FC_RCTL_DD_SOL_DATA:       /* write data */
 487         case FC_RCTL_DD_UNSOL_CTL:
 488         case FC_RCTL_DD_SOL_CTL:
 489         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 490         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 491         default:
 492                 pr_debug("%s: unhandled frame r_ctl %x\n",
 493                        __func__, fh->fh_r_ctl);
 494                 fc_frame_free(fp);
 495                 ft_sess_put(sess);      /* undo get from lookup */
 496                 break;
 497         }
 498 }
 499
 500 /*
 501  * Send new command to target.
 502  */
 503 static void ft_send_work(struct work_struct *work)
 504 {
 505         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 506         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 507         struct fcp_cmnd *fcp;
 508         int data_dir = 0;
 509         int task_attr;
 510
 511         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 512         if (!fcp)
 513                 goto err;
 514
 515         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 516                 goto err;               /* not handling longer CDBs yet */
 517
 518         /*
 519          * Check for FCP task management flags
 520          */
 521         if (fcp->fc_tm_flags) {
 522                 ft_send_tm(cmd);
 523                 return;
 524         }
 525
 526         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 527         case 0:
 528                 data_dir = DMA_NONE;
 529                 break;
 530         case FCP_CFL_RDDATA:
 531                 data_dir = DMA_FROM_DEVICE;
 532                 break;
 533         case FCP_CFL_WRDATA:
 534                 data_dir = DMA_TO_DEVICE;
 535                 break;
 536         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 537                 goto err;       /* TBD not supported by tcm_fc yet */
 538         }
 539         /*
 540          * Locate the SAM Task Attr from fc_pri_ta
 541          */
 542         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 543         case FCP_PTA_HEADQ:
 544                 task_attr = TCM_HEAD_TAG;
 545                 break;
 546         case FCP_PTA_ORDERED:
 547                 task_attr = TCM_ORDERED_TAG;
 548                 break;
 549         case FCP_PTA_ACA:
 550                 task_attr = TCM_ACA_TAG;
 551                 break;
 552         case FCP_PTA_SIMPLE: /* Fallthrough */
 553         default:
 554                 task_attr = TCM_SIMPLE_TAG;
 555         }
 556
 557         fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 558         cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
 559         /*
 560          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 561          * directly from ft_check_stop_free callback in response path.
 562          */
 563         if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 564                               &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 565                               ntohl(fcp->fc_dl), task_attr, data_dir,
 566                               TARGET_SCF_ACK_KREF | TARGET_SCF_USE_CPUID))
 567                 goto err;
 568
 569         pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
 570         return;
 571
 572 err:
 573         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 574 }