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.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi_device.h>
  35 #include <scsi/scsi_cmnd.h>
  36 #include <scsi/scsi_tcq.h>
  37 #include <scsi/libfc.h>
  38 #include <scsi/fc_encode.h>
  39
  40 #include <target/target_core_base.h>
  41 #include <target/target_core_fabric.h>
  42 #include <target/target_core_configfs.h>
  43 #include <target/configfs_macros.h>
  44
  45 #include "tcm_fc.h"
  46
  47 /*
  48  * Dump cmd state for debugging.
  49  */
  50 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  51 {
  52         struct fc_exch *ep;
  53         struct fc_seq *sp;
  54         struct se_cmd *se_cmd;
  55         struct scatterlist *sg;
  56         int count;
  57
  58         se_cmd = &cmd->se_cmd;
  59         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  60                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  61
  62         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  63                 caller, cmd, se_cmd->t_data_nents,
  64                se_cmd->data_length, se_cmd->se_cmd_flags);
  65
  66         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  67                 pr_debug("%s: cmd %p sg %p page %p "
  68                         "len 0x%x off 0x%x\n",
  69                         caller, cmd, sg,
  70                         sg_page(sg), sg->length, sg->offset);
  71
  72         sp = cmd->seq;
  73         if (sp) {
  74                 ep = fc_seq_exch(sp);
  75                 pr_debug("%s: cmd %p sid %x did %x "
  76                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  77                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  78                         sp->id, ep->esb_stat);
  79         }
  80 }
  81
  82 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  83 {
  84         if (unlikely(ft_debug_logging))
  85                 _ft_dump_cmd(cmd, caller);
  86 }
  87
  88 static void ft_free_cmd(struct ft_cmd *cmd)
  89 {
  90         struct fc_frame *fp;
  91         struct fc_lport *lport;
  92
  93         if (!cmd)
  94                 return;
  95         fp = cmd->req_frame;
  96         lport = fr_dev(fp);
  97         if (fr_seq(fp))
  98                 lport->tt.seq_release(fr_seq(fp));
  99         fc_frame_free(fp);
 100         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
 101         kfree(cmd);
 102 }
 103
 104 void ft_release_cmd(struct se_cmd *se_cmd)
 105 {
 106         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 107
 108         ft_free_cmd(cmd);
 109 }
 110
 111 int ft_check_stop_free(struct se_cmd *se_cmd)
 112 {
 113         transport_generic_free_cmd(se_cmd, 0);
 114         return 1;
 115 }
 116
 117 /*
 118  * Send response.
 119  */
 120 int ft_queue_status(struct se_cmd *se_cmd)
 121 {
 122         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 123         struct fc_frame *fp;
 124         struct fcp_resp_with_ext *fcp;
 125         struct fc_lport *lport;
 126         struct fc_exch *ep;
 127         size_t len;
 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                 /* XXX shouldn't just drop it - requeue and retry? */
 138                 return 0;
 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         lport->tt.seq_send(lport, cmd->seq, fp);
 171         lport->tt.exch_done(cmd->seq);
 172         return 0;
 173 }
 174
 175 int ft_write_pending_status(struct se_cmd *se_cmd)
 176 {
 177         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 178
 179         return cmd->write_data_len != se_cmd->data_length;
 180 }
 181
 182 /*
 183  * Send TX_RDY (transfer ready).
 184  */
 185 int ft_write_pending(struct se_cmd *se_cmd)
 186 {
 187         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 188         struct fc_frame *fp;
 189         struct fcp_txrdy *txrdy;
 190         struct fc_lport *lport;
 191         struct fc_exch *ep;
 192         struct fc_frame_header *fh;
 193         u32 f_ctl;
 194
 195         ft_dump_cmd(cmd, __func__);
 196
 197         if (cmd->aborted)
 198                 return 0;
 199         ep = fc_seq_exch(cmd->seq);
 200         lport = ep->lp;
 201         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 202         if (!fp)
 203                 return -ENOMEM; /* Signal QUEUE_FULL */
 204
 205         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 206         memset(txrdy, 0, sizeof(*txrdy));
 207         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 208
 209         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 210         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 211                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 212
 213         fh = fc_frame_header_get(fp);
 214         f_ctl = ntoh24(fh->fh_f_ctl);
 215
 216         /* Only if it is 'Exchange Responder' */
 217         if (f_ctl & FC_FC_EX_CTX) {
 218                 /* Target is 'exchange responder' and sending XFER_READY
 219                  * to 'exchange initiator (initiator)'
 220                  */
 221                 if ((ep->xid <= lport->lro_xid) &&
 222                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 223                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
 224                             lport->tt.ddp_target(lport, ep->xid,
 225                                                  se_cmd->t_data_sg,
 226                                                  se_cmd->t_data_nents))
 227                                 cmd->was_ddp_setup = 1;
 228                 }
 229         }
 230         lport->tt.seq_send(lport, cmd->seq, fp);
 231         return 0;
 232 }
 233
 234 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 235 {
 236         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 237
 238         if (cmd->aborted)
 239                 return ~0;
 240         return fc_seq_exch(cmd->seq)->rxid;
 241 }
 242
 243 int ft_get_cmd_state(struct se_cmd *se_cmd)
 244 {
 245         return 0;
 246 }
 247
 248 /*
 249  * FC sequence response handler for follow-on sequences (data) and aborts.
 250  */
 251 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 252 {
 253         struct ft_cmd *cmd = arg;
 254         struct fc_frame_header *fh;
 255
 256         if (unlikely(IS_ERR(fp))) {
 257                 /* XXX need to find cmd if queued */
 258                 cmd->seq = NULL;
 259                 cmd->aborted = true;
 260                 return;
 261         }
 262
 263         fh = fc_frame_header_get(fp);
 264
 265         switch (fh->fh_r_ctl) {
 266         case FC_RCTL_DD_SOL_DATA:       /* write data */
 267                 ft_recv_write_data(cmd, fp);
 268                 break;
 269         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 270         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 271         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 272         default:
 273                 pr_debug("%s: unhandled frame r_ctl %x\n",
 274                        __func__, fh->fh_r_ctl);
 275                 ft_invl_hw_context(cmd);
 276                 fc_frame_free(fp);
 277                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 278                 break;
 279         }
 280 }
 281
 282 /*
 283  * Send a FCP response including SCSI status and optional FCP rsp_code.
 284  * status is SAM_STAT_GOOD (zero) iff code is valid.
 285  * This is used in error cases, such as allocation failures.
 286  */
 287 static void ft_send_resp_status(struct fc_lport *lport,
 288                                 const struct fc_frame *rx_fp,
 289                                 u32 status, enum fcp_resp_rsp_codes code)
 290 {
 291         struct fc_frame *fp;
 292         struct fc_seq *sp;
 293         const struct fc_frame_header *fh;
 294         size_t len;
 295         struct fcp_resp_with_ext *fcp;
 296         struct fcp_resp_rsp_info *info;
 297
 298         fh = fc_frame_header_get(rx_fp);
 299         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 300                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 301         len = sizeof(*fcp);
 302         if (status == SAM_STAT_GOOD)
 303                 len += sizeof(*info);
 304         fp = fc_frame_alloc(lport, len);
 305         if (!fp)
 306                 return;
 307         fcp = fc_frame_payload_get(fp, len);
 308         memset(fcp, 0, len);
 309         fcp->resp.fr_status = status;
 310         if (status == SAM_STAT_GOOD) {
 311                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 312                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 313                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 314                 info->rsp_code = code;
 315         }
 316
 317         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 318         sp = fr_seq(fp);
 319         if (sp) {
 320                 lport->tt.seq_send(lport, sp, fp);
 321                 lport->tt.exch_done(sp);
 322         } else {
 323                 lport->tt.frame_send(lport, fp);
 324         }
 325 }
 326
 327 /*
 328  * Send error or task management response.
 329  */
 330 static void ft_send_resp_code(struct ft_cmd *cmd,
 331                               enum fcp_resp_rsp_codes code)
 332 {
 333         ft_send_resp_status(cmd->sess->tport->lport,
 334                             cmd->req_frame, SAM_STAT_GOOD, code);
 335 }
 336
 337
 338 /*
 339  * Send error or task management response.
 340  * Always frees the cmd and associated state.
 341  */
 342 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 343                                       enum fcp_resp_rsp_codes code)
 344 {
 345         ft_send_resp_code(cmd, code);
 346         ft_free_cmd(cmd);
 347 }
 348
 349 /*
 350  * Handle Task Management Request.
 351  */
 352 static void ft_send_tm(struct ft_cmd *cmd)
 353 {
 354         struct fcp_cmnd *fcp;
 355         int rc;
 356         u8 tm_func;
 357
 358         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 359
 360         switch (fcp->fc_tm_flags) {
 361         case FCP_TMF_LUN_RESET:
 362                 tm_func = TMR_LUN_RESET;
 363                 break;
 364         case FCP_TMF_TGT_RESET:
 365                 tm_func = TMR_TARGET_WARM_RESET;
 366                 break;
 367         case FCP_TMF_CLR_TASK_SET:
 368                 tm_func = TMR_CLEAR_TASK_SET;
 369                 break;
 370         case FCP_TMF_ABT_TASK_SET:
 371                 tm_func = TMR_ABORT_TASK_SET;
 372                 break;
 373         case FCP_TMF_CLR_ACA:
 374                 tm_func = TMR_CLEAR_ACA;
 375                 break;
 376         default:
 377                 /*
 378                  * FCP4r01 indicates having a combination of
 379                  * tm_flags set is invalid.
 380                  */
 381                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 382                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 383                 return;
 384         }
 385
 386         /* FIXME: Add referenced task tag for ABORT_TASK */
 387         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 388                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 389                 cmd, tm_func, GFP_KERNEL, 0, 0);
 390         if (rc < 0)
 391                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 392 }
 393
 394 /*
 395  * Send status from completed task management request.
 396  */
 397 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 398 {
 399         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 400         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 401         enum fcp_resp_rsp_codes code;
 402
 403         if (cmd->aborted)
 404                 return 0;
 405         switch (tmr->response) {
 406         case TMR_FUNCTION_COMPLETE:
 407                 code = FCP_TMF_CMPL;
 408                 break;
 409         case TMR_LUN_DOES_NOT_EXIST:
 410                 code = FCP_TMF_INVALID_LUN;
 411                 break;
 412         case TMR_FUNCTION_REJECTED:
 413                 code = FCP_TMF_REJECTED;
 414                 break;
 415         case TMR_TASK_DOES_NOT_EXIST:
 416         case TMR_TASK_STILL_ALLEGIANT:
 417         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 418         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 419         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 420         default:
 421                 code = FCP_TMF_FAILED;
 422                 break;
 423         }
 424         pr_debug("tmr fn %d resp %d fcp code %d\n",
 425                   tmr->function, tmr->response, code);
 426         ft_send_resp_code(cmd, code);
 427         return 0;
 428 }
 429
 430 static void ft_send_work(struct work_struct *work);
 431
 432 /*
 433  * Handle incoming FCP command.
 434  */
 435 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 436 {
 437         struct ft_cmd *cmd;
 438         struct fc_lport *lport = sess->tport->lport;
 439
 440         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 441         if (!cmd)
 442                 goto busy;
 443         cmd->sess = sess;
 444         cmd->seq = lport->tt.seq_assign(lport, fp);
 445         if (!cmd->seq) {
 446                 kfree(cmd);
 447                 goto busy;
 448         }
 449         cmd->req_frame = fp;            /* hold frame during cmd */
 450
 451         INIT_WORK(&cmd->work, ft_send_work);
 452         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 453         return;
 454
 455 busy:
 456         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 457         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 458         fc_frame_free(fp);
 459         ft_sess_put(sess);              /* undo get from lookup */
 460 }
 461
 462
 463 /*
 464  * Handle incoming FCP frame.
 465  * Caller has verified that the frame is type FCP.
 466  */
 467 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 468 {
 469         struct fc_frame_header *fh = fc_frame_header_get(fp);
 470
 471         switch (fh->fh_r_ctl) {
 472         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 473                 ft_recv_cmd(sess, fp);
 474                 break;
 475         case FC_RCTL_DD_SOL_DATA:       /* write data */
 476         case FC_RCTL_DD_UNSOL_CTL:
 477         case FC_RCTL_DD_SOL_CTL:
 478         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 479         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 480         default:
 481                 pr_debug("%s: unhandled frame r_ctl %x\n",
 482                        __func__, fh->fh_r_ctl);
 483                 fc_frame_free(fp);
 484                 ft_sess_put(sess);      /* undo get from lookup */
 485                 break;
 486         }
 487 }
 488
 489 /*
 490  * Send new command to target.
 491  */
 492 static void ft_send_work(struct work_struct *work)
 493 {
 494         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 495         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 496         struct fcp_cmnd *fcp;
 497         int data_dir = 0;
 498         int task_attr;
 499
 500         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 501         if (!fcp)
 502                 goto err;
 503
 504         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 505                 goto err;               /* not handling longer CDBs yet */
 506
 507         /*
 508          * Check for FCP task management flags
 509          */
 510         if (fcp->fc_tm_flags) {
 511                 ft_send_tm(cmd);
 512                 return;
 513         }
 514
 515         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 516         case 0:
 517                 data_dir = DMA_NONE;
 518                 break;
 519         case FCP_CFL_RDDATA:
 520                 data_dir = DMA_FROM_DEVICE;
 521                 break;
 522         case FCP_CFL_WRDATA:
 523                 data_dir = DMA_TO_DEVICE;
 524                 break;
 525         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 526                 goto err;       /* TBD not supported by tcm_fc yet */
 527         }
 528         /*
 529          * Locate the SAM Task Attr from fc_pri_ta
 530          */
 531         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 532         case FCP_PTA_HEADQ:
 533                 task_attr = MSG_HEAD_TAG;
 534                 break;
 535         case FCP_PTA_ORDERED:
 536                 task_attr = MSG_ORDERED_TAG;
 537                 break;
 538         case FCP_PTA_ACA:
 539                 task_attr = MSG_ACA_TAG;
 540                 break;
 541         case FCP_PTA_SIMPLE: /* Fallthrough */
 542         default:
 543                 task_attr = MSG_SIMPLE_TAG;
 544         }
 545
 546         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 547         /*
 548          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 549          * directly from ft_check_stop_free callback in response path.
 550          */
 551         if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 552                               &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 553                               ntohl(fcp->fc_dl), task_attr, data_dir, 0))
 554                 goto err;
 555
 556         pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
 557         return;
 558
 559 err:
 560         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 561 }