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 <generated/utsrelease.h>
  23 #include <linux/utsname.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/kthread.h>
  27 #include <linux/types.h>
  28 #include <linux/string.h>
  29 #include <linux/configfs.h>
  30 #include <linux/ctype.h>
  31 #include <linux/hash.h>
  32 #include <asm/unaligned.h>
  33 #include <scsi/scsi.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi_device.h>
  36 #include <scsi/scsi_cmnd.h>
  37 #include <scsi/scsi_tcq.h>
  38 #include <scsi/libfc.h>
  39 #include <scsi/fc_encode.h>
  40
  41 #include <target/target_core_base.h>
  42 #include <target/target_core_fabric.h>
  43 #include <target/target_core_configfs.h>
  44 #include <target/configfs_macros.h>
  45
  46 #include "tcm_fc.h"
  47
  48 /*
  49  * Dump cmd state for debugging.
  50  */
  51 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  52 {
  53         struct fc_exch *ep;
  54         struct fc_seq *sp;
  55         struct se_cmd *se_cmd;
  56         struct scatterlist *sg;
  57         int count;
  58
  59         se_cmd = &cmd->se_cmd;
  60         pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
  61                 caller, cmd, cmd->sess, cmd->seq, se_cmd);
  62
  63         pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
  64                 caller, cmd, se_cmd->t_data_nents,
  65                se_cmd->data_length, se_cmd->se_cmd_flags);
  66
  67         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
  68                 pr_debug("%s: cmd %p sg %p page %p "
  69                         "len 0x%x off 0x%x\n",
  70                         caller, cmd, sg,
  71                         sg_page(sg), sg->length, sg->offset);
  72
  73         sp = cmd->seq;
  74         if (sp) {
  75                 ep = fc_seq_exch(sp);
  76                 pr_debug("%s: cmd %p sid %x did %x "
  77                         "ox_id %x rx_id %x seq_id %x e_stat %x\n",
  78                         caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  79                         sp->id, ep->esb_stat);
  80         }
  81 }
  82
  83 static void ft_free_cmd(struct ft_cmd *cmd)
  84 {
  85         struct fc_frame *fp;
  86         struct fc_lport *lport;
  87
  88         if (!cmd)
  89                 return;
  90         fp = cmd->req_frame;
  91         lport = fr_dev(fp);
  92         if (fr_seq(fp))
  93                 lport->tt.seq_release(fr_seq(fp));
  94         fc_frame_free(fp);
  95         ft_sess_put(cmd->sess); /* undo get from lookup at recv */
  96         kfree(cmd);
  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         transport_generic_free_cmd(se_cmd, 0);
 109         return 1;
 110 }
 111
 112 /*
 113  * Send response.
 114  */
 115 int ft_queue_status(struct se_cmd *se_cmd)
 116 {
 117         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 118         struct fc_frame *fp;
 119         struct fcp_resp_with_ext *fcp;
 120         struct fc_lport *lport;
 121         struct fc_exch *ep;
 122         size_t len;
 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                 /* XXX shouldn't just drop it - requeue and retry? */
 133                 return 0;
 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 = lport->tt.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         lport->tt.seq_send(lport, cmd->seq, fp);
 166         lport->tt.exch_done(cmd->seq);
 167         return 0;
 168 }
 169
 170 int ft_write_pending_status(struct se_cmd *se_cmd)
 171 {
 172         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 173
 174         return cmd->write_data_len != se_cmd->data_length;
 175 }
 176
 177 /*
 178  * Send TX_RDY (transfer ready).
 179  */
 180 int ft_write_pending(struct se_cmd *se_cmd)
 181 {
 182         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 183         struct fc_frame *fp;
 184         struct fcp_txrdy *txrdy;
 185         struct fc_lport *lport;
 186         struct fc_exch *ep;
 187         struct fc_frame_header *fh;
 188         u32 f_ctl;
 189
 190         ft_dump_cmd(cmd, __func__);
 191
 192         if (cmd->aborted)
 193                 return 0;
 194         ep = fc_seq_exch(cmd->seq);
 195         lport = ep->lp;
 196         fp = fc_frame_alloc(lport, sizeof(*txrdy));
 197         if (!fp)
 198                 return -ENOMEM; /* Signal QUEUE_FULL */
 199
 200         txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
 201         memset(txrdy, 0, sizeof(*txrdy));
 202         txrdy->ft_burst_len = htonl(se_cmd->data_length);
 203
 204         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 205         fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
 206                        FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
 207
 208         fh = fc_frame_header_get(fp);
 209         f_ctl = ntoh24(fh->fh_f_ctl);
 210
 211         /* Only if it is 'Exchange Responder' */
 212         if (f_ctl & FC_FC_EX_CTX) {
 213                 /* Target is 'exchange responder' and sending XFER_READY
 214                  * to 'exchange initiator (initiator)'
 215                  */
 216                 if ((ep->xid <= lport->lro_xid) &&
 217                     (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
 218                         if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) &&
 219                             lport->tt.ddp_target(lport, ep->xid,
 220                                                  se_cmd->t_data_sg,
 221                                                  se_cmd->t_data_nents))
 222                                 cmd->was_ddp_setup = 1;
 223                 }
 224         }
 225         lport->tt.seq_send(lport, cmd->seq, fp);
 226         return 0;
 227 }
 228
 229 u32 ft_get_task_tag(struct se_cmd *se_cmd)
 230 {
 231         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 232
 233         return fc_seq_exch(cmd->seq)->rxid;
 234 }
 235
 236 int ft_get_cmd_state(struct se_cmd *se_cmd)
 237 {
 238         return 0;
 239 }
 240
 241 /*
 242  * FC sequence response handler for follow-on sequences (data) and aborts.
 243  */
 244 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 245 {
 246         struct ft_cmd *cmd = arg;
 247         struct fc_frame_header *fh;
 248
 249         if (unlikely(IS_ERR(fp))) {
 250                 /* XXX need to find cmd if queued */
 251                 cmd->seq = NULL;
 252                 cmd->aborted = true;
 253                 return;
 254         }
 255
 256         fh = fc_frame_header_get(fp);
 257
 258         switch (fh->fh_r_ctl) {
 259         case FC_RCTL_DD_SOL_DATA:       /* write data */
 260                 ft_recv_write_data(cmd, fp);
 261                 break;
 262         case FC_RCTL_DD_UNSOL_CTL:      /* command */
 263         case FC_RCTL_DD_SOL_CTL:        /* transfer ready */
 264         case FC_RCTL_DD_DATA_DESC:      /* transfer ready */
 265         default:
 266                 pr_debug("%s: unhandled frame r_ctl %x\n",
 267                        __func__, fh->fh_r_ctl);
 268                 ft_invl_hw_context(cmd);
 269                 fc_frame_free(fp);
 270                 transport_generic_free_cmd(&cmd->se_cmd, 0);
 271                 break;
 272         }
 273 }
 274
 275 /*
 276  * Send a FCP response including SCSI status and optional FCP rsp_code.
 277  * status is SAM_STAT_GOOD (zero) iff code is valid.
 278  * This is used in error cases, such as allocation failures.
 279  */
 280 static void ft_send_resp_status(struct fc_lport *lport,
 281                                 const struct fc_frame *rx_fp,
 282                                 u32 status, enum fcp_resp_rsp_codes code)
 283 {
 284         struct fc_frame *fp;
 285         struct fc_seq *sp;
 286         const struct fc_frame_header *fh;
 287         size_t len;
 288         struct fcp_resp_with_ext *fcp;
 289         struct fcp_resp_rsp_info *info;
 290
 291         fh = fc_frame_header_get(rx_fp);
 292         pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
 293                   ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
 294         len = sizeof(*fcp);
 295         if (status == SAM_STAT_GOOD)
 296                 len += sizeof(*info);
 297         fp = fc_frame_alloc(lport, len);
 298         if (!fp)
 299                 return;
 300         fcp = fc_frame_payload_get(fp, len);
 301         memset(fcp, 0, len);
 302         fcp->resp.fr_status = status;
 303         if (status == SAM_STAT_GOOD) {
 304                 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
 305                 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
 306                 info = (struct fcp_resp_rsp_info *)(fcp + 1);
 307                 info->rsp_code = code;
 308         }
 309
 310         fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
 311         sp = fr_seq(fp);
 312         if (sp) {
 313                 lport->tt.seq_send(lport, sp, fp);
 314                 lport->tt.exch_done(sp);
 315         } else {
 316                 lport->tt.frame_send(lport, fp);
 317         }
 318 }
 319
 320 /*
 321  * Send error or task management response.
 322  */
 323 static void ft_send_resp_code(struct ft_cmd *cmd,
 324                               enum fcp_resp_rsp_codes code)
 325 {
 326         ft_send_resp_status(cmd->sess->tport->lport,
 327                             cmd->req_frame, SAM_STAT_GOOD, code);
 328 }
 329
 330
 331 /*
 332  * Send error or task management response.
 333  * Always frees the cmd and associated state.
 334  */
 335 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
 336                                       enum fcp_resp_rsp_codes code)
 337 {
 338         ft_send_resp_code(cmd, code);
 339         ft_free_cmd(cmd);
 340 }
 341
 342 /*
 343  * Handle Task Management Request.
 344  */
 345 static void ft_send_tm(struct ft_cmd *cmd)
 346 {
 347         struct fcp_cmnd *fcp;
 348         int rc;
 349         u8 tm_func;
 350
 351         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 352
 353         switch (fcp->fc_tm_flags) {
 354         case FCP_TMF_LUN_RESET:
 355                 tm_func = TMR_LUN_RESET;
 356                 break;
 357         case FCP_TMF_TGT_RESET:
 358                 tm_func = TMR_TARGET_WARM_RESET;
 359                 break;
 360         case FCP_TMF_CLR_TASK_SET:
 361                 tm_func = TMR_CLEAR_TASK_SET;
 362                 break;
 363         case FCP_TMF_ABT_TASK_SET:
 364                 tm_func = TMR_ABORT_TASK_SET;
 365                 break;
 366         case FCP_TMF_CLR_ACA:
 367                 tm_func = TMR_CLEAR_ACA;
 368                 break;
 369         default:
 370                 /*
 371                  * FCP4r01 indicates having a combination of
 372                  * tm_flags set is invalid.
 373                  */
 374                 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
 375                 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 376                 return;
 377         }
 378
 379         /* FIXME: Add referenced task tag for ABORT_TASK */
 380         rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
 381                 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 382                 cmd, tm_func, GFP_KERNEL, 0, 0);
 383         if (rc < 0)
 384                 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
 385 }
 386
 387 /*
 388  * Send status from completed task management request.
 389  */
 390 int ft_queue_tm_resp(struct se_cmd *se_cmd)
 391 {
 392         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
 393         struct se_tmr_req *tmr = se_cmd->se_tmr_req;
 394         enum fcp_resp_rsp_codes code;
 395
 396         if (cmd->aborted)
 397                 return 0;
 398         switch (tmr->response) {
 399         case TMR_FUNCTION_COMPLETE:
 400                 code = FCP_TMF_CMPL;
 401                 break;
 402         case TMR_LUN_DOES_NOT_EXIST:
 403                 code = FCP_TMF_INVALID_LUN;
 404                 break;
 405         case TMR_FUNCTION_REJECTED:
 406                 code = FCP_TMF_REJECTED;
 407                 break;
 408         case TMR_TASK_DOES_NOT_EXIST:
 409         case TMR_TASK_STILL_ALLEGIANT:
 410         case TMR_TASK_FAILOVER_NOT_SUPPORTED:
 411         case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
 412         case TMR_FUNCTION_AUTHORIZATION_FAILED:
 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         return 0;
 421 }
 422
 423 static void ft_send_work(struct work_struct *work);
 424
 425 /*
 426  * Handle incoming FCP command.
 427  */
 428 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
 429 {
 430         struct ft_cmd *cmd;
 431         struct fc_lport *lport = sess->tport->lport;
 432
 433         cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
 434         if (!cmd)
 435                 goto busy;
 436         cmd->sess = sess;
 437         cmd->seq = lport->tt.seq_assign(lport, fp);
 438         if (!cmd->seq) {
 439                 kfree(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 = MSG_HEAD_TAG;
 527                 break;
 528         case FCP_PTA_ORDERED:
 529                 task_attr = MSG_ORDERED_TAG;
 530                 break;
 531         case FCP_PTA_ACA:
 532                 task_attr = MSG_ACA_TAG;
 533                 break;
 534         case FCP_PTA_SIMPLE: /* Fallthrough */
 535         default:
 536                 task_attr = MSG_SIMPLE_TAG;
 537         }
 538
 539         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 540         /*
 541          * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 542          * directly from ft_check_stop_free callback in response path.
 543          */
 544         target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
 545                         &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
 546                         ntohl(fcp->fc_dl), task_attr, data_dir, 0);
 547         pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
 548         return;
 549
 550 err:
 551         ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
 552 }