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 40 #include "tcm_fc.h" 41 42 /* 43 * Dump cmd state for debugging. 44 */ 45 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 46 { 47 struct fc_exch *ep; 48 struct fc_seq *sp; 49 struct se_cmd *se_cmd; 50 struct scatterlist *sg; 51 int count; 52 53 se_cmd = &cmd->se_cmd; 54 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n", 55 caller, cmd, cmd->sess, cmd->seq, se_cmd); 56 57 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n", 58 caller, cmd, se_cmd->t_data_nents, 59 se_cmd->data_length, se_cmd->se_cmd_flags); 60 61 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count) 62 pr_debug("%s: cmd %p sg %p page %p " 63 "len 0x%x off 0x%x\n", 64 caller, cmd, sg, 65 sg_page(sg), sg->length, sg->offset); 66 67 sp = cmd->seq; 68 if (sp) { 69 ep = fc_seq_exch(sp); 70 pr_debug("%s: cmd %p sid %x did %x " 71 "ox_id %x rx_id %x seq_id %x e_stat %x\n", 72 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid, 73 sp->id, ep->esb_stat); 74 } 75 } 76 77 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 78 { 79 if (unlikely(ft_debug_logging)) 80 _ft_dump_cmd(cmd, caller); 81 } 82 83 static void ft_free_cmd(struct ft_cmd *cmd) 84 { 85 struct fc_frame *fp; 86 struct fc_lport *lport; 87 struct ft_sess *sess; 88 89 if (!cmd) 90 return; 91 sess = cmd->sess; 92 fp = cmd->req_frame; 93 lport = fr_dev(fp); 94 if (fr_seq(fp)) 95 lport->tt.seq_release(fr_seq(fp)); 96 fc_frame_free(fp); 97 percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag); 98 ft_sess_put(sess); /* undo get from lookup at recv */ 99 } 100 101 void ft_release_cmd(struct se_cmd *se_cmd) 102 { 103 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 104 105 ft_free_cmd(cmd); 106 } 107 108 int ft_check_stop_free(struct se_cmd *se_cmd) 109 { 110 return transport_generic_free_cmd(se_cmd, 0); 111 } 112 113 /* 114 * Send response. 115 */ 116 int ft_queue_status(struct se_cmd *se_cmd) 117 { 118 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 119 struct fc_frame *fp; 120 struct fcp_resp_with_ext *fcp; 121 struct fc_lport *lport; 122 struct fc_exch *ep; 123 size_t len; 124 int rc; 125 126 if (cmd->aborted) 127 return 0; 128 ft_dump_cmd(cmd, __func__); 129 ep = fc_seq_exch(cmd->seq); 130 lport = ep->lp; 131 len = sizeof(*fcp) + se_cmd->scsi_sense_length; 132 fp = fc_frame_alloc(lport, len); 133 if (!fp) { 134 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 135 return -ENOMEM; 136 } 137 138 fcp = fc_frame_payload_get(fp, len); 139 memset(fcp, 0, len); 140 fcp->resp.fr_status = se_cmd->scsi_status; 141 142 len = se_cmd->scsi_sense_length; 143 if (len) { 144 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL; 145 fcp->ext.fr_sns_len = htonl(len); 146 memcpy((fcp + 1), se_cmd->sense_buffer, len); 147 } 148 149 /* 150 * Test underflow and overflow with one mask. Usually both are off. 151 * Bidirectional commands are not handled yet. 152 */ 153 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) { 154 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) 155 fcp->resp.fr_flags |= FCP_RESID_OVER; 156 else 157 fcp->resp.fr_flags |= FCP_RESID_UNDER; 158 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count); 159 } 160 161 /* 162 * Send response. 163 */ 164 cmd->seq = lport->tt.seq_start_next(cmd->seq); 165 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP, 166 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0); 167 168 rc = lport->tt.seq_send(lport, cmd->seq, fp); 169 if (rc) { 170 pr_info_ratelimited("%s: Failed to send response frame %p, " 171 "xid <0x%x>\n", __func__, fp, ep->xid); 172 /* 173 * Generate a TASK_SET_FULL status to notify the initiator 174 * to reduce it's queue_depth after the se_cmd response has 175 * been re-queued by target-core. 176 */ 177 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 178 return -ENOMEM; 179 } 180 lport->tt.exch_done(cmd->seq); 181 /* 182 * Drop the extra ACK_KREF reference taken by target_submit_cmd() 183 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 184 * final se_cmd->cmd_kref put. 185 */ 186 target_put_sess_cmd(&cmd->se_cmd); 187 return 0; 188 } 189 190 int ft_write_pending_status(struct se_cmd *se_cmd) 191 { 192 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 193 194 return cmd->write_data_len != se_cmd->data_length; 195 } 196 197 /* 198 * Send TX_RDY (transfer ready). 199 */ 200 int ft_write_pending(struct se_cmd *se_cmd) 201 { 202 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 203 struct fc_frame *fp; 204 struct fcp_txrdy *txrdy; 205 struct fc_lport *lport; 206 struct fc_exch *ep; 207 struct fc_frame_header *fh; 208 u32 f_ctl; 209 210 ft_dump_cmd(cmd, __func__); 211 212 if (cmd->aborted) 213 return 0; 214 ep = fc_seq_exch(cmd->seq); 215 lport = ep->lp; 216 fp = fc_frame_alloc(lport, sizeof(*txrdy)); 217 if (!fp) 218 return -ENOMEM; /* Signal QUEUE_FULL */ 219 220 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy)); 221 memset(txrdy, 0, sizeof(*txrdy)); 222 txrdy->ft_burst_len = htonl(se_cmd->data_length); 223 224 cmd->seq = lport->tt.seq_start_next(cmd->seq); 225 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP, 226 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); 227 228 fh = fc_frame_header_get(fp); 229 f_ctl = ntoh24(fh->fh_f_ctl); 230 231 /* Only if it is 'Exchange Responder' */ 232 if (f_ctl & FC_FC_EX_CTX) { 233 /* Target is 'exchange responder' and sending XFER_READY 234 * to 'exchange initiator (initiator)' 235 */ 236 if ((ep->xid <= lport->lro_xid) && 237 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) { 238 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && 239 lport->tt.ddp_target(lport, ep->xid, 240 se_cmd->t_data_sg, 241 se_cmd->t_data_nents)) 242 cmd->was_ddp_setup = 1; 243 } 244 } 245 lport->tt.seq_send(lport, cmd->seq, fp); 246 return 0; 247 } 248 249 int ft_get_cmd_state(struct se_cmd *se_cmd) 250 { 251 return 0; 252 } 253 254 /* 255 * FC sequence response handler for follow-on sequences (data) and aborts. 256 */ 257 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg) 258 { 259 struct ft_cmd *cmd = arg; 260 struct fc_frame_header *fh; 261 262 if (IS_ERR(fp)) { 263 /* XXX need to find cmd if queued */ 264 cmd->seq = NULL; 265 cmd->aborted = true; 266 return; 267 } 268 269 fh = fc_frame_header_get(fp); 270 271 switch (fh->fh_r_ctl) { 272 case FC_RCTL_DD_SOL_DATA: /* write data */ 273 ft_recv_write_data(cmd, fp); 274 break; 275 case FC_RCTL_DD_UNSOL_CTL: /* command */ 276 case FC_RCTL_DD_SOL_CTL: /* transfer ready */ 277 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 278 default: 279 pr_debug("%s: unhandled frame r_ctl %x\n", 280 __func__, fh->fh_r_ctl); 281 ft_invl_hw_context(cmd); 282 fc_frame_free(fp); 283 transport_generic_free_cmd(&cmd->se_cmd, 0); 284 break; 285 } 286 } 287 288 /* 289 * Send a FCP response including SCSI status and optional FCP rsp_code. 290 * status is SAM_STAT_GOOD (zero) iff code is valid. 291 * This is used in error cases, such as allocation failures. 292 */ 293 static void ft_send_resp_status(struct fc_lport *lport, 294 const struct fc_frame *rx_fp, 295 u32 status, enum fcp_resp_rsp_codes code) 296 { 297 struct fc_frame *fp; 298 struct fc_seq *sp; 299 const struct fc_frame_header *fh; 300 size_t len; 301 struct fcp_resp_with_ext *fcp; 302 struct fcp_resp_rsp_info *info; 303 304 fh = fc_frame_header_get(rx_fp); 305 pr_debug("FCP error response: did %x oxid %x status %x code %x\n", 306 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code); 307 len = sizeof(*fcp); 308 if (status == SAM_STAT_GOOD) 309 len += sizeof(*info); 310 fp = fc_frame_alloc(lport, len); 311 if (!fp) 312 return; 313 fcp = fc_frame_payload_get(fp, len); 314 memset(fcp, 0, len); 315 fcp->resp.fr_status = status; 316 if (status == SAM_STAT_GOOD) { 317 fcp->ext.fr_rsp_len = htonl(sizeof(*info)); 318 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL; 319 info = (struct fcp_resp_rsp_info *)(fcp + 1); 320 info->rsp_code = code; 321 } 322 323 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0); 324 sp = fr_seq(fp); 325 if (sp) { 326 lport->tt.seq_send(lport, sp, fp); 327 lport->tt.exch_done(sp); 328 } else { 329 lport->tt.frame_send(lport, fp); 330 } 331 } 332 333 /* 334 * Send error or task management response. 335 */ 336 static void ft_send_resp_code(struct ft_cmd *cmd, 337 enum fcp_resp_rsp_codes code) 338 { 339 ft_send_resp_status(cmd->sess->tport->lport, 340 cmd->req_frame, SAM_STAT_GOOD, code); 341 } 342 343 344 /* 345 * Send error or task management response. 346 * Always frees the cmd and associated state. 347 */ 348 static void ft_send_resp_code_and_free(struct ft_cmd *cmd, 349 enum fcp_resp_rsp_codes code) 350 { 351 ft_send_resp_code(cmd, code); 352 ft_free_cmd(cmd); 353 } 354 355 /* 356 * Handle Task Management Request. 357 */ 358 static void ft_send_tm(struct ft_cmd *cmd) 359 { 360 struct fcp_cmnd *fcp; 361 int rc; 362 u8 tm_func; 363 364 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 365 366 switch (fcp->fc_tm_flags) { 367 case FCP_TMF_LUN_RESET: 368 tm_func = TMR_LUN_RESET; 369 break; 370 case FCP_TMF_TGT_RESET: 371 tm_func = TMR_TARGET_WARM_RESET; 372 break; 373 case FCP_TMF_CLR_TASK_SET: 374 tm_func = TMR_CLEAR_TASK_SET; 375 break; 376 case FCP_TMF_ABT_TASK_SET: 377 tm_func = TMR_ABORT_TASK_SET; 378 break; 379 case FCP_TMF_CLR_ACA: 380 tm_func = TMR_CLEAR_ACA; 381 break; 382 default: 383 /* 384 * FCP4r01 indicates having a combination of 385 * tm_flags set is invalid. 386 */ 387 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags); 388 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 389 return; 390 } 391 392 /* FIXME: Add referenced task tag for ABORT_TASK */ 393 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess, 394 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 395 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF); 396 if (rc < 0) 397 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED); 398 } 399 400 /* 401 * Send status from completed task management request. 402 */ 403 void ft_queue_tm_resp(struct se_cmd *se_cmd) 404 { 405 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 406 struct se_tmr_req *tmr = se_cmd->se_tmr_req; 407 enum fcp_resp_rsp_codes code; 408 409 if (cmd->aborted) 410 return; 411 switch (tmr->response) { 412 case TMR_FUNCTION_COMPLETE: 413 code = FCP_TMF_CMPL; 414 break; 415 case TMR_LUN_DOES_NOT_EXIST: 416 code = FCP_TMF_INVALID_LUN; 417 break; 418 case TMR_FUNCTION_REJECTED: 419 code = FCP_TMF_REJECTED; 420 break; 421 case TMR_TASK_DOES_NOT_EXIST: 422 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED: 423 default: 424 code = FCP_TMF_FAILED; 425 break; 426 } 427 pr_debug("tmr fn %d resp %d fcp code %d\n", 428 tmr->function, tmr->response, code); 429 ft_send_resp_code(cmd, code); 430 /* 431 * Drop the extra ACK_KREF reference taken by target_submit_tmr() 432 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 433 * final se_cmd->cmd_kref put. 434 */ 435 target_put_sess_cmd(&cmd->se_cmd); 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 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid; 568 /* 569 * Use a single se_cmd->cmd_kref as we expect to release se_cmd 570 * directly from ft_check_stop_free callback in response path. 571 */ 572 if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb, 573 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 574 ntohl(fcp->fc_dl), task_attr, data_dir, 575 TARGET_SCF_ACK_KREF)) 576 goto err; 577 578 pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl); 579 return; 580 581 err: 582 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 583 } 584