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 #include <target/target_core_configfs.h> 40 #include <target/configfs_macros.h> 41 42 #include "tcm_fc.h" 43 44 /* 45 * Dump cmd state for debugging. 46 */ 47 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 48 { 49 struct fc_exch *ep; 50 struct fc_seq *sp; 51 struct se_cmd *se_cmd; 52 struct scatterlist *sg; 53 int count; 54 55 se_cmd = &cmd->se_cmd; 56 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n", 57 caller, cmd, cmd->sess, cmd->seq, se_cmd); 58 59 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n", 60 caller, cmd, se_cmd->t_data_nents, 61 se_cmd->data_length, se_cmd->se_cmd_flags); 62 63 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count) 64 pr_debug("%s: cmd %p sg %p page %p " 65 "len 0x%x off 0x%x\n", 66 caller, cmd, sg, 67 sg_page(sg), sg->length, sg->offset); 68 69 sp = cmd->seq; 70 if (sp) { 71 ep = fc_seq_exch(sp); 72 pr_debug("%s: cmd %p sid %x did %x " 73 "ox_id %x rx_id %x seq_id %x e_stat %x\n", 74 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid, 75 sp->id, ep->esb_stat); 76 } 77 } 78 79 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 80 { 81 if (unlikely(ft_debug_logging)) 82 _ft_dump_cmd(cmd, caller); 83 } 84 85 static void ft_free_cmd(struct ft_cmd *cmd) 86 { 87 struct fc_frame *fp; 88 struct fc_lport *lport; 89 struct ft_sess *sess; 90 91 if (!cmd) 92 return; 93 sess = cmd->sess; 94 fp = cmd->req_frame; 95 lport = fr_dev(fp); 96 if (fr_seq(fp)) 97 lport->tt.seq_release(fr_seq(fp)); 98 fc_frame_free(fp); 99 percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag); 100 ft_sess_put(sess); /* undo get from lookup at recv */ 101 } 102 103 void ft_release_cmd(struct se_cmd *se_cmd) 104 { 105 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 106 107 ft_free_cmd(cmd); 108 } 109 110 int ft_check_stop_free(struct se_cmd *se_cmd) 111 { 112 transport_generic_free_cmd(se_cmd, 0); 113 return 1; 114 } 115 116 /* 117 * Send response. 118 */ 119 int ft_queue_status(struct se_cmd *se_cmd) 120 { 121 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 122 struct fc_frame *fp; 123 struct fcp_resp_with_ext *fcp; 124 struct fc_lport *lport; 125 struct fc_exch *ep; 126 size_t len; 127 int rc; 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 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 138 return -ENOMEM; 139 } 140 141 fcp = fc_frame_payload_get(fp, len); 142 memset(fcp, 0, len); 143 fcp->resp.fr_status = se_cmd->scsi_status; 144 145 len = se_cmd->scsi_sense_length; 146 if (len) { 147 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL; 148 fcp->ext.fr_sns_len = htonl(len); 149 memcpy((fcp + 1), se_cmd->sense_buffer, len); 150 } 151 152 /* 153 * Test underflow and overflow with one mask. Usually both are off. 154 * Bidirectional commands are not handled yet. 155 */ 156 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) { 157 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) 158 fcp->resp.fr_flags |= FCP_RESID_OVER; 159 else 160 fcp->resp.fr_flags |= FCP_RESID_UNDER; 161 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count); 162 } 163 164 /* 165 * Send response. 166 */ 167 cmd->seq = lport->tt.seq_start_next(cmd->seq); 168 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP, 169 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0); 170 171 rc = lport->tt.seq_send(lport, cmd->seq, fp); 172 if (rc) { 173 pr_info_ratelimited("%s: Failed to send response frame %p, " 174 "xid <0x%x>\n", __func__, fp, ep->xid); 175 /* 176 * Generate a TASK_SET_FULL status to notify the initiator 177 * to reduce it's queue_depth after the se_cmd response has 178 * been re-queued by target-core. 179 */ 180 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 181 return -ENOMEM; 182 } 183 lport->tt.exch_done(cmd->seq); 184 return 0; 185 } 186 187 int ft_write_pending_status(struct se_cmd *se_cmd) 188 { 189 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 190 191 return cmd->write_data_len != se_cmd->data_length; 192 } 193 194 /* 195 * Send TX_RDY (transfer ready). 196 */ 197 int ft_write_pending(struct se_cmd *se_cmd) 198 { 199 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 200 struct fc_frame *fp; 201 struct fcp_txrdy *txrdy; 202 struct fc_lport *lport; 203 struct fc_exch *ep; 204 struct fc_frame_header *fh; 205 u32 f_ctl; 206 207 ft_dump_cmd(cmd, __func__); 208 209 if (cmd->aborted) 210 return 0; 211 ep = fc_seq_exch(cmd->seq); 212 lport = ep->lp; 213 fp = fc_frame_alloc(lport, sizeof(*txrdy)); 214 if (!fp) 215 return -ENOMEM; /* Signal QUEUE_FULL */ 216 217 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy)); 218 memset(txrdy, 0, sizeof(*txrdy)); 219 txrdy->ft_burst_len = htonl(se_cmd->data_length); 220 221 cmd->seq = lport->tt.seq_start_next(cmd->seq); 222 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP, 223 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); 224 225 fh = fc_frame_header_get(fp); 226 f_ctl = ntoh24(fh->fh_f_ctl); 227 228 /* Only if it is 'Exchange Responder' */ 229 if (f_ctl & FC_FC_EX_CTX) { 230 /* Target is 'exchange responder' and sending XFER_READY 231 * to 'exchange initiator (initiator)' 232 */ 233 if ((ep->xid <= lport->lro_xid) && 234 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) { 235 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && 236 lport->tt.ddp_target(lport, ep->xid, 237 se_cmd->t_data_sg, 238 se_cmd->t_data_nents)) 239 cmd->was_ddp_setup = 1; 240 } 241 } 242 lport->tt.seq_send(lport, cmd->seq, fp); 243 return 0; 244 } 245 246 u32 ft_get_task_tag(struct se_cmd *se_cmd) 247 { 248 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 249 250 if (cmd->aborted) 251 return ~0; 252 return fc_seq_exch(cmd->seq)->rxid; 253 } 254 255 int ft_get_cmd_state(struct se_cmd *se_cmd) 256 { 257 return 0; 258 } 259 260 /* 261 * FC sequence response handler for follow-on sequences (data) and aborts. 262 */ 263 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg) 264 { 265 struct ft_cmd *cmd = arg; 266 struct fc_frame_header *fh; 267 268 if (unlikely(IS_ERR(fp))) { 269 /* XXX need to find cmd if queued */ 270 cmd->seq = NULL; 271 cmd->aborted = true; 272 return; 273 } 274 275 fh = fc_frame_header_get(fp); 276 277 switch (fh->fh_r_ctl) { 278 case FC_RCTL_DD_SOL_DATA: /* write data */ 279 ft_recv_write_data(cmd, fp); 280 break; 281 case FC_RCTL_DD_UNSOL_CTL: /* command */ 282 case FC_RCTL_DD_SOL_CTL: /* transfer ready */ 283 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 284 default: 285 pr_debug("%s: unhandled frame r_ctl %x\n", 286 __func__, fh->fh_r_ctl); 287 ft_invl_hw_context(cmd); 288 fc_frame_free(fp); 289 transport_generic_free_cmd(&cmd->se_cmd, 0); 290 break; 291 } 292 } 293 294 /* 295 * Send a FCP response including SCSI status and optional FCP rsp_code. 296 * status is SAM_STAT_GOOD (zero) iff code is valid. 297 * This is used in error cases, such as allocation failures. 298 */ 299 static void ft_send_resp_status(struct fc_lport *lport, 300 const struct fc_frame *rx_fp, 301 u32 status, enum fcp_resp_rsp_codes code) 302 { 303 struct fc_frame *fp; 304 struct fc_seq *sp; 305 const struct fc_frame_header *fh; 306 size_t len; 307 struct fcp_resp_with_ext *fcp; 308 struct fcp_resp_rsp_info *info; 309 310 fh = fc_frame_header_get(rx_fp); 311 pr_debug("FCP error response: did %x oxid %x status %x code %x\n", 312 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code); 313 len = sizeof(*fcp); 314 if (status == SAM_STAT_GOOD) 315 len += sizeof(*info); 316 fp = fc_frame_alloc(lport, len); 317 if (!fp) 318 return; 319 fcp = fc_frame_payload_get(fp, len); 320 memset(fcp, 0, len); 321 fcp->resp.fr_status = status; 322 if (status == SAM_STAT_GOOD) { 323 fcp->ext.fr_rsp_len = htonl(sizeof(*info)); 324 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL; 325 info = (struct fcp_resp_rsp_info *)(fcp + 1); 326 info->rsp_code = code; 327 } 328 329 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0); 330 sp = fr_seq(fp); 331 if (sp) { 332 lport->tt.seq_send(lport, sp, fp); 333 lport->tt.exch_done(sp); 334 } else { 335 lport->tt.frame_send(lport, fp); 336 } 337 } 338 339 /* 340 * Send error or task management response. 341 */ 342 static void ft_send_resp_code(struct ft_cmd *cmd, 343 enum fcp_resp_rsp_codes code) 344 { 345 ft_send_resp_status(cmd->sess->tport->lport, 346 cmd->req_frame, SAM_STAT_GOOD, code); 347 } 348 349 350 /* 351 * Send error or task management response. 352 * Always frees the cmd and associated state. 353 */ 354 static void ft_send_resp_code_and_free(struct ft_cmd *cmd, 355 enum fcp_resp_rsp_codes code) 356 { 357 ft_send_resp_code(cmd, code); 358 ft_free_cmd(cmd); 359 } 360 361 /* 362 * Handle Task Management Request. 363 */ 364 static void ft_send_tm(struct ft_cmd *cmd) 365 { 366 struct fcp_cmnd *fcp; 367 int rc; 368 u8 tm_func; 369 370 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 371 372 switch (fcp->fc_tm_flags) { 373 case FCP_TMF_LUN_RESET: 374 tm_func = TMR_LUN_RESET; 375 break; 376 case FCP_TMF_TGT_RESET: 377 tm_func = TMR_TARGET_WARM_RESET; 378 break; 379 case FCP_TMF_CLR_TASK_SET: 380 tm_func = TMR_CLEAR_TASK_SET; 381 break; 382 case FCP_TMF_ABT_TASK_SET: 383 tm_func = TMR_ABORT_TASK_SET; 384 break; 385 case FCP_TMF_CLR_ACA: 386 tm_func = TMR_CLEAR_ACA; 387 break; 388 default: 389 /* 390 * FCP4r01 indicates having a combination of 391 * tm_flags set is invalid. 392 */ 393 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags); 394 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 395 return; 396 } 397 398 /* FIXME: Add referenced task tag for ABORT_TASK */ 399 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess, 400 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 401 cmd, tm_func, GFP_KERNEL, 0, 0); 402 if (rc < 0) 403 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED); 404 } 405 406 /* 407 * Send status from completed task management request. 408 */ 409 void ft_queue_tm_resp(struct se_cmd *se_cmd) 410 { 411 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 412 struct se_tmr_req *tmr = se_cmd->se_tmr_req; 413 enum fcp_resp_rsp_codes code; 414 415 if (cmd->aborted) 416 return; 417 switch (tmr->response) { 418 case TMR_FUNCTION_COMPLETE: 419 code = FCP_TMF_CMPL; 420 break; 421 case TMR_LUN_DOES_NOT_EXIST: 422 code = FCP_TMF_INVALID_LUN; 423 break; 424 case TMR_FUNCTION_REJECTED: 425 code = FCP_TMF_REJECTED; 426 break; 427 case TMR_TASK_DOES_NOT_EXIST: 428 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED: 429 default: 430 code = FCP_TMF_FAILED; 431 break; 432 } 433 pr_debug("tmr fn %d resp %d fcp code %d\n", 434 tmr->function, tmr->response, code); 435 ft_send_resp_code(cmd, code); 436 } 437 438 void ft_aborted_task(struct se_cmd *se_cmd) 439 { 440 return; 441 } 442 443 static void ft_send_work(struct work_struct *work); 444 445 /* 446 * Handle incoming FCP command. 447 */ 448 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) 449 { 450 struct ft_cmd *cmd; 451 struct fc_lport *lport = sess->tport->lport; 452 struct se_session *se_sess = sess->se_sess; 453 int tag; 454 455 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); 456 if (tag < 0) 457 goto busy; 458 459 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag]; 460 memset(cmd, 0, sizeof(struct ft_cmd)); 461 462 cmd->se_cmd.map_tag = tag; 463 cmd->sess = sess; 464 cmd->seq = lport->tt.seq_assign(lport, fp); 465 if (!cmd->seq) { 466 percpu_ida_free(&se_sess->sess_tag_pool, tag); 467 goto busy; 468 } 469 cmd->req_frame = fp; /* hold frame during cmd */ 470 471 INIT_WORK(&cmd->work, ft_send_work); 472 queue_work(sess->tport->tpg->workqueue, &cmd->work); 473 return; 474 475 busy: 476 pr_debug("cmd or seq allocation failure - sending BUSY\n"); 477 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0); 478 fc_frame_free(fp); 479 ft_sess_put(sess); /* undo get from lookup */ 480 } 481 482 483 /* 484 * Handle incoming FCP frame. 485 * Caller has verified that the frame is type FCP. 486 */ 487 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp) 488 { 489 struct fc_frame_header *fh = fc_frame_header_get(fp); 490 491 switch (fh->fh_r_ctl) { 492 case FC_RCTL_DD_UNSOL_CMD: /* command */ 493 ft_recv_cmd(sess, fp); 494 break; 495 case FC_RCTL_DD_SOL_DATA: /* write data */ 496 case FC_RCTL_DD_UNSOL_CTL: 497 case FC_RCTL_DD_SOL_CTL: 498 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 499 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */ 500 default: 501 pr_debug("%s: unhandled frame r_ctl %x\n", 502 __func__, fh->fh_r_ctl); 503 fc_frame_free(fp); 504 ft_sess_put(sess); /* undo get from lookup */ 505 break; 506 } 507 } 508 509 /* 510 * Send new command to target. 511 */ 512 static void ft_send_work(struct work_struct *work) 513 { 514 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 515 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame); 516 struct fcp_cmnd *fcp; 517 int data_dir = 0; 518 int task_attr; 519 520 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 521 if (!fcp) 522 goto err; 523 524 if (fcp->fc_flags & FCP_CFL_LEN_MASK) 525 goto err; /* not handling longer CDBs yet */ 526 527 /* 528 * Check for FCP task management flags 529 */ 530 if (fcp->fc_tm_flags) { 531 ft_send_tm(cmd); 532 return; 533 } 534 535 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) { 536 case 0: 537 data_dir = DMA_NONE; 538 break; 539 case FCP_CFL_RDDATA: 540 data_dir = DMA_FROM_DEVICE; 541 break; 542 case FCP_CFL_WRDATA: 543 data_dir = DMA_TO_DEVICE; 544 break; 545 case FCP_CFL_WRDATA | FCP_CFL_RDDATA: 546 goto err; /* TBD not supported by tcm_fc yet */ 547 } 548 /* 549 * Locate the SAM Task Attr from fc_pri_ta 550 */ 551 switch (fcp->fc_pri_ta & FCP_PTA_MASK) { 552 case FCP_PTA_HEADQ: 553 task_attr = TCM_HEAD_TAG; 554 break; 555 case FCP_PTA_ORDERED: 556 task_attr = TCM_ORDERED_TAG; 557 break; 558 case FCP_PTA_ACA: 559 task_attr = TCM_ACA_TAG; 560 break; 561 case FCP_PTA_SIMPLE: /* Fallthrough */ 562 default: 563 task_attr = TCM_SIMPLE_TAG; 564 } 565 566 fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd); 567 /* 568 * Use a single se_cmd->cmd_kref as we expect to release se_cmd 569 * directly from ft_check_stop_free callback in response path. 570 */ 571 if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb, 572 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 573 ntohl(fcp->fc_dl), task_attr, data_dir, 0)) 574 goto err; 575 576 pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl); 577 return; 578 579 err: 580 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 581 } 582