drivers/target/tcm_fc/tfc_cmd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010 Cisco Systems, Inc.
   4  */
   5
   6 /* XXX TBD some includes may be extraneous */
   7
   8 #include <linux/module.h>
   9 #include <linux/moduleparam.h>
  10 #include <linux/utsname.h>
  11 #include <linux/init.h>
  12 #include <linux/slab.h>
  13 #include <linux/kthread.h>
  14 #include <linux/types.h>
  15 #include <linux/string.h>
  16 #include <linux/configfs.h>
  17 #include <linux/ctype.h>
  18 #include <linux/hash.h>
  19 #include <asm/unaligned.h>
  20 #include <scsi/scsi_tcq.h>
  21 #include <scsi/libfc.h>
  22
  23 #include <target/target_core_base.h>
  24 #include <target/target_core_fabric.h>
  25
  26 #include "tcm_fc.h"
  27
  28 /*
  29  * Dump cmd state for debugging.
  30  */
  31 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  32 {
  33         struct fc_exch *ep;
  34         struct fc_seq *sp;
  35         struct se_cmd *se_cmd;
  36         struct scatterlist *sg;
  37         int count;
  38
  39         se_cmd = &cmd->se_cmd;
  40         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  41                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  42
  43         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  44                 caller, cmd, se_cmd->t_data_nents,
  45                se_cmd->data_length, se_cmd->se_cmd_flags);
  46
  47         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  48                 pr_debug("%s: cmd %p sg %p page %p "
  49                         "len 0x%x off 0x%x\n",
  50                         caller, cmd, sg,
  51                         sg_page(sg), sg->length, sg->offset);
  52
  53         sp = cmd->seq;
  54         if (sp) {
  55                 ep = fc_seq_exch(sp);
  56                 pr_debug("%s: cmd %p sid %x did %x "
  57                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  58                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  59                         sp->id, ep->esb_stat);
  60         }
  61 }
  62
  63 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  64 {
  65         if (unlikely(ft_debug_logging))
  66                 _ft_dump_cmd(cmd, caller);
  67 }
  68
  69 static void ft_free_cmd(struct ft_cmd *cmd)
  70 {
  71         struct fc_frame *fp;
  72         struct ft_sess *sess;
  73
  74         if (!cmd)
  75                 return;
  76         sess = cmd->sess;
  77         fp = cmd->req_frame;
  78         if (fr_seq(fp))
  79                 fc_seq_release(fr_seq(fp));
  80         fc_frame_free(fp);
  81         target_free_tag(sess->se_sess, &cmd->se_cmd);
  82         ft_sess_put(sess);      /* undo get from lookup at recv */
  83 }
  84
  85 void ft_release_cmd(struct se_cmd *se_cmd)
  86 {
  87         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  88
  89         ft_free_cmd(cmd);
  90 }
  91
  92 int ft_check_stop_free(struct se_cmd *se_cmd)
  93 {
  94         return transport_generic_free_cmd(se_cmd, 0);
  95 }
  96
  97 /*
  98  * Send response.
  99  */
 100 int ft_queue_status(struct se_cmd *se_cmd)
 101 {
 102         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 103         struct fc_frame *fp;
 104         struct fcp_resp_with_ext *fcp;
 105         struct fc_lport *lport;
 106         struct fc_exch *ep;
 107         size_t len;
 108         int rc;
 109
 110         if (cmd->aborted)
 111                 return 0;
 112         ft_dump_cmd(cmd, __func__);
 113         ep = fc_seq_exch(cmd->seq);
 114         lport = ep->lp;
 115         len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 116         fp = fc_frame_alloc(lport, len);
 117         if (!fp) {
 118                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 119                 return -ENOMEM;
 120         }
 121
 122         fcp = fc_frame_payload_get(fp, len);
 123         memset(fcp, 0, len);
 124         fcp->resp.fr_status = se_cmd->scsi_status;
 125
 126         len = se_cmd->scsi_sense_length;
 127         if (len) {
 128                 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
 129                 fcp->ext.fr_sns_len = htonl(len);
 130                 memcpy((fcp + 1), se_cmd->sense_buffer, len);
 131         }
 132
 133         /*
 134          * Test underflow and overflow with one mask.  Usually both are off.
 135          * Bidirectional commands are not handled yet.
 136          */
 137         if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
 138                 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
 139                         fcp->resp.fr_flags |= FCP_RESID_OVER;
 140                 else
 141                         fcp->resp.fr_flags |= FCP_RESID_UNDER;
 142                 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
 143         }
 144
 145         /*
 146          * Send response.
 147          */
 148         cmd->seq = fc_seq_start_next(cmd->seq);
 149         fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 150                        FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 151
 152         rc = fc_seq_send(lport, cmd->seq, fp);
 153         if (rc) {
 154                 pr_info_ratelimited("%s: Failed to send response frame %p, "
 155                                     "xid <0x%x>\n", __func__, fp, ep->xid);
 156                 /*
 157                  * Generate a TASK_SET_FULL status to notify the initiator
 158                  * to reduce it's queue_depth after the se_cmd response has
 159                  * been re-queued by target-core.
 160                  */
 161                 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 162                 return -ENOMEM;
 163         }
 164         fc_exch_done(cmd->seq);
 165         /*
 166          * Drop the extra ACK_KREF reference taken by target_submit_cmd()
 167          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 168          * final se_cmd->cmd_kref put.
 169          */
 170         target_put_sess_cmd(&cmd->se_cmd);
 171         return 0;
 172 }
 173
 174 /*
 175  * Send TX_RDY (transfer ready).
 176  */
 177 int ft_write_pending(struct se_cmd *se_cmd)
 178 {
 179         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 180         struct fc_frame *fp;
 181         struct fcp_txrdy *txrdy;
 182         struct fc_lport *lport;
 183         struct fc_exch *ep;
 184         struct fc_frame_header *fh;
 185         u32 f_ctl;
 186
 187         ft_dump_cmd(cmd, __func__);
 188
 189         if (cmd->aborted)
 190                 return 0;
 191         ep = fc_seq_exch(cmd->seq);
 192         lport = ep->lp;
 193         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 194         if (!fp)
 195                 return -ENOMEM; /* Signal QUEUE_FULL */
 196
 197         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 198         memset(txrdy, 0, sizeof(*txrdy));
 199         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 200
 201         cmd->seq = fc_seq_start_next(cmd->seq);
 202         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 203                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 204
 205         fh = fc_frame_header_get(fp);
 206         f_ctl = ntoh24(fh->fh_f_ctl);
 207
 208         /* Only if it is 'Exchange Responder' */
 209         if (f_ctl & FC_FC_EX_CTX) {
 210                 /* Target is 'exchange responder' and sending XFER_READY
 211                  * to 'exchange initiator (initiator)'
 212                  */
 213                 if ((ep->xid <= lport->lro_xid) &&
 214                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 215                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
 216                             lport->tt.ddp_target(lport, ep->xid,
 217                                                  se_cmd->t_data_sg,
 218                                                  se_cmd->t_data_nents))
 219                                 cmd->was_ddp_setup = 1;
 220                 }
 221         }
 222         fc_seq_send(lport, cmd->seq, fp);
 223         return 0;
 224 }
 225
 226 /*
 227  * FC sequence response handler for follow-on sequences (data) and aborts.
 228  */
 229 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 230 {
 231         struct ft_cmd *cmd = arg;
 232         struct fc_frame_header *fh;
 233
 234         if (IS_ERR(fp)) {
 235                 /* XXX need to find cmd if queued */
 236                 cmd->seq = NULL;
 237                 cmd->aborted = true;
 238                 return;
 239         }
 240
 241         fh = fc_frame_header_get(fp);
 242
 243         switch (fh->fh_r_ctl) {
 244         case FC_RCTL_DD_SOL_DATA:       /* write data */
 245                 ft_recv_write_data(cmd, fp);
 246                 break;
 247         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 248         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 249         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 250         default:
 251                 pr_debug("%s: unhandled frame r_ctl %x\n",
 252                        __func__, fh->fh_r_ctl);
 253                 ft_invl_hw_context(cmd);
 254                 fc_frame_free(fp);
 255                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 256                 break;
 257         }
 258 }
 259
 260 /*
 261  * Send a FCP response including SCSI status and optional FCP rsp_code.
 262  * status is SAM_STAT_GOOD (zero) iff code is valid.
 263  * This is used in error cases, such as allocation failures.
 264  */
 265 static void ft_send_resp_status(struct fc_lport *lport,
 266                                 const struct fc_frame *rx_fp,
 267                                 u32 status, enum fcp_resp_rsp_codes code)
 268 {
 269         struct fc_frame *fp;
 270         struct fc_seq *sp;
 271         const struct fc_frame_header *fh;
 272         size_t len;
 273         struct fcp_resp_with_ext *fcp;
 274         struct fcp_resp_rsp_info *info;
 275
 276         fh = fc_frame_header_get(rx_fp);
 277         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 278                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 279         len = sizeof(*fcp);
 280         if (status == SAM_STAT_GOOD)
 281                 len += sizeof(*info);
 282         fp = fc_frame_alloc(lport, len);
 283         if (!fp)
 284                 return;
 285         fcp = fc_frame_payload_get(fp, len);
 286         memset(fcp, 0, len);
 287         fcp->resp.fr_status = status;
 288         if (status == SAM_STAT_GOOD) {
 289                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 290                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 291                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 292                 info->rsp_code = code;
 293         }
 294
 295         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 296         sp = fr_seq(fp);
 297         if (sp) {
 298                 fc_seq_send(lport, sp, fp);
 299                 fc_exch_done(sp);
 300         } else {
 301                 lport->tt.frame_send(lport, fp);
 302         }
 303 }
 304
 305 /*
 306  * Send error or task management response.
 307  */
 308 static void ft_send_resp_code(struct ft_cmd *cmd,
 309                               enum fcp_resp_rsp_codes code)
 310 {
 311         ft_send_resp_status(cmd->sess->tport->lport,
 312                             cmd->req_frame, SAM_STAT_GOOD, code);
 313 }
 314
 315
 316 /*
 317  * Send error or task management response.
 318  * Always frees the cmd and associated state.
 319  */
 320 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 321                                       enum fcp_resp_rsp_codes code)
 322 {
 323         ft_send_resp_code(cmd, code);
 324         ft_free_cmd(cmd);
 325 }
 326
 327 /*
 328  * Handle Task Management Request.
 329  */
 330 static void ft_send_tm(struct ft_cmd *cmd)
 331 {
 332         struct fcp_cmnd *fcp;
 333         int rc;
 334         u8 tm_func;
 335
 336         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 337
 338         switch (fcp->fc_tm_flags) {
 339         case FCP_TMF_LUN_RESET:
 340                 tm_func = TMR_LUN_RESET;
 341                 break;
 342         case FCP_TMF_TGT_RESET:
 343                 tm_func = TMR_TARGET_WARM_RESET;
 344                 break;
 345         case FCP_TMF_CLR_TASK_SET:
 346                 tm_func = TMR_CLEAR_TASK_SET;
 347                 break;
 348         case FCP_TMF_ABT_TASK_SET:
 349                 tm_func = TMR_ABORT_TASK_SET;
 350                 break;
 351         case FCP_TMF_CLR_ACA:
 352                 tm_func = TMR_CLEAR_ACA;
 353                 break;
 354         default:
 355                 /*
 356                  * FCP4r01 indicates having a combination of
 357                  * tm_flags set is invalid.
 358                  */
 359                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 360                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 361                 return;
 362         }
 363
 364         /* FIXME: Add referenced task tag for ABORT_TASK */
 365         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 366                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 367                 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
 368         if (rc < 0)
 369                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 370 }
 371
 372 /*
 373  * Send status from completed task management request.
 374  */
 375 void ft_queue_tm_resp(struct se_cmd *se_cmd)
 376 {
 377         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 378         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 379         enum fcp_resp_rsp_codes code;
 380
 381         if (cmd->aborted)
 382                 return;
 383         switch (tmr->response) {
 384         case TMR_FUNCTION_COMPLETE:
 385                 code = FCP_TMF_CMPL;
 386                 break;
 387         case TMR_LUN_DOES_NOT_EXIST:
 388                 code = FCP_TMF_INVALID_LUN;
 389                 break;
 390         case TMR_FUNCTION_REJECTED:
 391                 code = FCP_TMF_REJECTED;
 392                 break;
 393         case TMR_TASK_DOES_NOT_EXIST:
 394         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 395         default:
 396                 code = FCP_TMF_FAILED;
 397                 break;
 398         }
 399         pr_debug("tmr fn %d resp %d fcp code %d\n",
 400                   tmr->function, tmr->response, code);
 401         ft_send_resp_code(cmd, code);
 402         /*
 403          * Drop the extra ACK_KREF reference taken by target_submit_tmr()
 404          * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
 405          * final se_cmd->cmd_kref put.
 406          */
 407         target_put_sess_cmd(&cmd->se_cmd);
 408 }
 409
 410 void ft_aborted_task(struct se_cmd *se_cmd)
 411 {
 412         return;
 413 }
 414
 415 static void ft_send_work(struct work_struct *work);
 416
 417 /*
 418  * Handle incoming FCP command.
 419  */
 420 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 421 {
 422         struct ft_cmd *cmd;
 423         struct fc_lport *lport = sess->tport->lport;
 424         struct se_session *se_sess = sess->se_sess;
 425         int tag, cpu;
 426
 427         tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
 428         if (tag < 0)
 429                 goto busy;
 430
 431         cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
 432         memset(cmd, 0, sizeof(struct ft_cmd));
 433
 434         cmd->se_cmd.map_tag = tag;
 435         cmd->se_cmd.map_cpu = cpu;
 436         cmd->sess = sess;
 437         cmd->seq = fc_seq_assign(lport, fp);
 438         if (!cmd->seq) {
 439                 target_free_tag(se_sess, &cmd->se_cmd);
 440                 goto busy;
 441         }
 442         cmd->req_frame = fp;            /* hold frame during cmd */
 443
 444         INIT_WORK(&cmd->work, ft_send_work);
 445         queue_work(sess->tport->tpg->workqueue, &cmd->work);
 446         return;
 447
 448 busy:
 449         pr_debug("cmd or seq allocation failure - sending BUSY\n");
 450         ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
 451         fc_frame_free(fp);
 452         ft_sess_put(sess);              /* undo get from lookup */
 453 }
 454
 455
 456 /*
 457  * Handle incoming FCP frame.
 458  * Caller has verified that the frame is type FCP.
 459  */
 460 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
 461 {
 462         struct fc_frame_header *fh = fc_frame_header_get(fp);
 463
 464         switch (fh->fh_r_ctl) {
 465         case FC_RCTL_DD_UNSOL_CMD:      /* command */
 466                 ft_recv_cmd(sess, fp);
 467                 break;
 468         case FC_RCTL_DD_SOL_DATA:       /* write data */
 469         case FC_RCTL_DD_UNSOL_CTL:
 470         case FC_RCTL_DD_SOL_CTL:
 471         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 472         case FC_RCTL_ELS4_REQ:          /* SRR, perhaps */
 473         default:
 474                 pr_debug("%s: unhandled frame r_ctl %x\n",
 475                        __func__, fh->fh_r_ctl);
 476                 fc_frame_free(fp);
 477                 ft_sess_put(sess);      /* undo get from lookup */
 478                 break;
 479         }
 480 }
 481
 482 /*
 483  * Send new command to target.
 484  */
 485 static void ft_send_work(struct work_struct *work)
 486 {
 487         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 488         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
 489         struct fcp_cmnd *fcp;
 490         int data_dir = 0;
 491         int task_attr;
 492
 493         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 494         if (!fcp)
 495                 goto err;
 496
 497         if (fcp->fc_flags & FCP_CFL_LEN_MASK)
 498                 goto err;               /* not handling longer CDBs yet */
 499
 500         /*
 501          * Check for FCP task management flags
 502          */
 503         if (fcp->fc_tm_flags) {
 504                 ft_send_tm(cmd);
 505                 return;
 506         }
 507
 508         switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
 509         case 0:
 510                 data_dir = DMA_NONE;
 511                 break;
 512         case FCP_CFL_RDDATA:
 513                 data_dir = DMA_FROM_DEVICE;
 514                 break;
 515         case FCP_CFL_WRDATA:
 516                 data_dir = DMA_TO_DEVICE;
 517                 break;
 518         case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
 519                 goto err;       /* TBD not supported by tcm_fc yet */
 520         }
 521         /*
 522          * Locate the SAM Task Attr from fc_pri_ta
 523          */
 524         switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 525         case FCP_PTA_HEADQ:
 526                 task_attr = TCM_HEAD_TAG;
 527                 break;
 528         case FCP_PTA_ORDERED:
 529                 task_attr = TCM_ORDERED_TAG;
 530                 break;
 531         case FCP_PTA_ACA:
 532                 task_attr = TCM_ACA_TAG;
 533                 break;
 534         case FCP_PTA_SIMPLE:
 535         default:
 536                 task_attr = TCM_SIMPLE_TAG;
 537         }
 538
 539         fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 540         cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
 541
 542         /*
 543          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 544          * directly from ft_check_stop_free callback in response path.
 545          */
 546         if (target_init_cmd(&cmd->se_cmd, cmd->sess->se_sess,
 547                             &cmd->ft_sense_buffer[0],
 548                             scsilun_to_int(&fcp->fc_lun), ntohl(fcp->fc_dl),
 549                             task_attr, data_dir, TARGET_SCF_ACK_KREF))
 550                 goto err;
 551
 552         if (target_submit_prep(&cmd->se_cmd, fcp->fc_cdb, NULL, 0, NULL, 0,
 553                                NULL, 0, GFP_KERNEL))
 554                 return;
 555
 556         target_submit(&cmd->se_cmd);
 557         pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
 558         return;
 559
 560 err:
 561         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 562 }