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 ft_sess *sess; 87 88 if (!cmd) 89 return; 90 sess = cmd->sess; 91 fp = cmd->req_frame; 92 if (fr_seq(fp)) 93 fc_seq_release(fr_seq(fp)); 94 fc_frame_free(fp); 95 percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag); 96 ft_sess_put(sess); /* undo get from lookup at recv */ 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 return transport_generic_free_cmd(se_cmd, 0); 109 } 110 111 /* 112 * Send response. 113 */ 114 int ft_queue_status(struct se_cmd *se_cmd) 115 { 116 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 117 struct fc_frame *fp; 118 struct fcp_resp_with_ext *fcp; 119 struct fc_lport *lport; 120 struct fc_exch *ep; 121 size_t len; 122 int rc; 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 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 133 return -ENOMEM; 134 } 135 136 fcp = fc_frame_payload_get(fp, len); 137 memset(fcp, 0, len); 138 fcp->resp.fr_status = se_cmd->scsi_status; 139 140 len = se_cmd->scsi_sense_length; 141 if (len) { 142 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL; 143 fcp->ext.fr_sns_len = htonl(len); 144 memcpy((fcp + 1), se_cmd->sense_buffer, len); 145 } 146 147 /* 148 * Test underflow and overflow with one mask. Usually both are off. 149 * Bidirectional commands are not handled yet. 150 */ 151 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) { 152 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) 153 fcp->resp.fr_flags |= FCP_RESID_OVER; 154 else 155 fcp->resp.fr_flags |= FCP_RESID_UNDER; 156 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count); 157 } 158 159 /* 160 * Send response. 161 */ 162 cmd->seq = fc_seq_start_next(cmd->seq); 163 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP, 164 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0); 165 166 rc = fc_seq_send(lport, cmd->seq, fp); 167 if (rc) { 168 pr_info_ratelimited("%s: Failed to send response frame %p, " 169 "xid <0x%x>\n", __func__, fp, ep->xid); 170 /* 171 * Generate a TASK_SET_FULL status to notify the initiator 172 * to reduce it's queue_depth after the se_cmd response has 173 * been re-queued by target-core. 174 */ 175 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 176 return -ENOMEM; 177 } 178 fc_exch_done(cmd->seq); 179 /* 180 * Drop the extra ACK_KREF reference taken by target_submit_cmd() 181 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 182 * final se_cmd->cmd_kref put. 183 */ 184 target_put_sess_cmd(&cmd->se_cmd); 185 return 0; 186 } 187 188 int ft_write_pending_status(struct se_cmd *se_cmd) 189 { 190 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 191 192 return cmd->write_data_len != se_cmd->data_length; 193 } 194 195 /* 196 * Send TX_RDY (transfer ready). 197 */ 198 int ft_write_pending(struct se_cmd *se_cmd) 199 { 200 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 201 struct fc_frame *fp; 202 struct fcp_txrdy *txrdy; 203 struct fc_lport *lport; 204 struct fc_exch *ep; 205 struct fc_frame_header *fh; 206 u32 f_ctl; 207 208 ft_dump_cmd(cmd, __func__); 209 210 if (cmd->aborted) 211 return 0; 212 ep = fc_seq_exch(cmd->seq); 213 lport = ep->lp; 214 fp = fc_frame_alloc(lport, sizeof(*txrdy)); 215 if (!fp) 216 return -ENOMEM; /* Signal QUEUE_FULL */ 217 218 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy)); 219 memset(txrdy, 0, sizeof(*txrdy)); 220 txrdy->ft_burst_len = htonl(se_cmd->data_length); 221 222 cmd->seq = fc_seq_start_next(cmd->seq); 223 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP, 224 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); 225 226 fh = fc_frame_header_get(fp); 227 f_ctl = ntoh24(fh->fh_f_ctl); 228 229 /* Only if it is 'Exchange Responder' */ 230 if (f_ctl & FC_FC_EX_CTX) { 231 /* Target is 'exchange responder' and sending XFER_READY 232 * to 'exchange initiator (initiator)' 233 */ 234 if ((ep->xid <= lport->lro_xid) && 235 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) { 236 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && 237 lport->tt.ddp_target(lport, ep->xid, 238 se_cmd->t_data_sg, 239 se_cmd->t_data_nents)) 240 cmd->was_ddp_setup = 1; 241 } 242 } 243 fc_seq_send(lport, cmd->seq, fp); 244 return 0; 245 } 246 247 int ft_get_cmd_state(struct se_cmd *se_cmd) 248 { 249 return 0; 250 } 251 252 /* 253 * FC sequence response handler for follow-on sequences (data) and aborts. 254 */ 255 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg) 256 { 257 struct ft_cmd *cmd = arg; 258 struct fc_frame_header *fh; 259 260 if (IS_ERR(fp)) { 261 /* XXX need to find cmd if queued */ 262 cmd->seq = NULL; 263 cmd->aborted = true; 264 return; 265 } 266 267 fh = fc_frame_header_get(fp); 268 269 switch (fh->fh_r_ctl) { 270 case FC_RCTL_DD_SOL_DATA: /* write data */ 271 ft_recv_write_data(cmd, fp); 272 break; 273 case FC_RCTL_DD_UNSOL_CTL: /* command */ 274 case FC_RCTL_DD_SOL_CTL: /* transfer ready */ 275 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 276 default: 277 pr_debug("%s: unhandled frame r_ctl %x\n", 278 __func__, fh->fh_r_ctl); 279 ft_invl_hw_context(cmd); 280 fc_frame_free(fp); 281 transport_generic_free_cmd(&cmd->se_cmd, 0); 282 break; 283 } 284 } 285 286 /* 287 * Send a FCP response including SCSI status and optional FCP rsp_code. 288 * status is SAM_STAT_GOOD (zero) iff code is valid. 289 * This is used in error cases, such as allocation failures. 290 */ 291 static void ft_send_resp_status(struct fc_lport *lport, 292 const struct fc_frame *rx_fp, 293 u32 status, enum fcp_resp_rsp_codes code) 294 { 295 struct fc_frame *fp; 296 struct fc_seq *sp; 297 const struct fc_frame_header *fh; 298 size_t len; 299 struct fcp_resp_with_ext *fcp; 300 struct fcp_resp_rsp_info *info; 301 302 fh = fc_frame_header_get(rx_fp); 303 pr_debug("FCP error response: did %x oxid %x status %x code %x\n", 304 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code); 305 len = sizeof(*fcp); 306 if (status == SAM_STAT_GOOD) 307 len += sizeof(*info); 308 fp = fc_frame_alloc(lport, len); 309 if (!fp) 310 return; 311 fcp = fc_frame_payload_get(fp, len); 312 memset(fcp, 0, len); 313 fcp->resp.fr_status = status; 314 if (status == SAM_STAT_GOOD) { 315 fcp->ext.fr_rsp_len = htonl(sizeof(*info)); 316 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL; 317 info = (struct fcp_resp_rsp_info *)(fcp + 1); 318 info->rsp_code = code; 319 } 320 321 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0); 322 sp = fr_seq(fp); 323 if (sp) { 324 fc_seq_send(lport, sp, fp); 325 fc_exch_done(sp); 326 } else { 327 lport->tt.frame_send(lport, fp); 328 } 329 } 330 331 /* 332 * Send error or task management response. 333 */ 334 static void ft_send_resp_code(struct ft_cmd *cmd, 335 enum fcp_resp_rsp_codes code) 336 { 337 ft_send_resp_status(cmd->sess->tport->lport, 338 cmd->req_frame, SAM_STAT_GOOD, code); 339 } 340 341 342 /* 343 * Send error or task management response. 344 * Always frees the cmd and associated state. 345 */ 346 static void ft_send_resp_code_and_free(struct ft_cmd *cmd, 347 enum fcp_resp_rsp_codes code) 348 { 349 ft_send_resp_code(cmd, code); 350 ft_free_cmd(cmd); 351 } 352 353 /* 354 * Handle Task Management Request. 355 */ 356 static void ft_send_tm(struct ft_cmd *cmd) 357 { 358 struct fcp_cmnd *fcp; 359 int rc; 360 u8 tm_func; 361 362 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 363 364 switch (fcp->fc_tm_flags) { 365 case FCP_TMF_LUN_RESET: 366 tm_func = TMR_LUN_RESET; 367 break; 368 case FCP_TMF_TGT_RESET: 369 tm_func = TMR_TARGET_WARM_RESET; 370 break; 371 case FCP_TMF_CLR_TASK_SET: 372 tm_func = TMR_CLEAR_TASK_SET; 373 break; 374 case FCP_TMF_ABT_TASK_SET: 375 tm_func = TMR_ABORT_TASK_SET; 376 break; 377 case FCP_TMF_CLR_ACA: 378 tm_func = TMR_CLEAR_ACA; 379 break; 380 default: 381 /* 382 * FCP4r01 indicates having a combination of 383 * tm_flags set is invalid. 384 */ 385 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags); 386 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 387 return; 388 } 389 390 /* FIXME: Add referenced task tag for ABORT_TASK */ 391 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess, 392 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 393 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF); 394 if (rc < 0) 395 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED); 396 } 397 398 /* 399 * Send status from completed task management request. 400 */ 401 void ft_queue_tm_resp(struct se_cmd *se_cmd) 402 { 403 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 404 struct se_tmr_req *tmr = se_cmd->se_tmr_req; 405 enum fcp_resp_rsp_codes code; 406 407 if (cmd->aborted) 408 return; 409 switch (tmr->response) { 410 case TMR_FUNCTION_COMPLETE: 411 code = FCP_TMF_CMPL; 412 break; 413 case TMR_LUN_DOES_NOT_EXIST: 414 code = FCP_TMF_INVALID_LUN; 415 break; 416 case TMR_FUNCTION_REJECTED: 417 code = FCP_TMF_REJECTED; 418 break; 419 case TMR_TASK_DOES_NOT_EXIST: 420 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED: 421 default: 422 code = FCP_TMF_FAILED; 423 break; 424 } 425 pr_debug("tmr fn %d resp %d fcp code %d\n", 426 tmr->function, tmr->response, code); 427 ft_send_resp_code(cmd, code); 428 /* 429 * Drop the extra ACK_KREF reference taken by target_submit_tmr() 430 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 431 * final se_cmd->cmd_kref put. 432 */ 433 target_put_sess_cmd(&cmd->se_cmd); 434 } 435 436 void ft_aborted_task(struct se_cmd *se_cmd) 437 { 438 return; 439 } 440 441 static void ft_send_work(struct work_struct *work); 442 443 /* 444 * Handle incoming FCP command. 445 */ 446 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) 447 { 448 struct ft_cmd *cmd; 449 struct fc_lport *lport = sess->tport->lport; 450 struct se_session *se_sess = sess->se_sess; 451 int tag; 452 453 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); 454 if (tag < 0) 455 goto busy; 456 457 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag]; 458 memset(cmd, 0, sizeof(struct ft_cmd)); 459 460 cmd->se_cmd.map_tag = tag; 461 cmd->sess = sess; 462 cmd->seq = fc_seq_assign(lport, fp); 463 if (!cmd->seq) { 464 percpu_ida_free(&se_sess->sess_tag_pool, tag); 465 goto busy; 466 } 467 cmd->req_frame = fp; /* hold frame during cmd */ 468 469 INIT_WORK(&cmd->work, ft_send_work); 470 queue_work(sess->tport->tpg->workqueue, &cmd->work); 471 return; 472 473 busy: 474 pr_debug("cmd or seq allocation failure - sending BUSY\n"); 475 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0); 476 fc_frame_free(fp); 477 ft_sess_put(sess); /* undo get from lookup */ 478 } 479 480 481 /* 482 * Handle incoming FCP frame. 483 * Caller has verified that the frame is type FCP. 484 */ 485 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp) 486 { 487 struct fc_frame_header *fh = fc_frame_header_get(fp); 488 489 switch (fh->fh_r_ctl) { 490 case FC_RCTL_DD_UNSOL_CMD: /* command */ 491 ft_recv_cmd(sess, fp); 492 break; 493 case FC_RCTL_DD_SOL_DATA: /* write data */ 494 case FC_RCTL_DD_UNSOL_CTL: 495 case FC_RCTL_DD_SOL_CTL: 496 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 497 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */ 498 default: 499 pr_debug("%s: unhandled frame r_ctl %x\n", 500 __func__, fh->fh_r_ctl); 501 fc_frame_free(fp); 502 ft_sess_put(sess); /* undo get from lookup */ 503 break; 504 } 505 } 506 507 /* 508 * Send new command to target. 509 */ 510 static void ft_send_work(struct work_struct *work) 511 { 512 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 513 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame); 514 struct fcp_cmnd *fcp; 515 int data_dir = 0; 516 int task_attr; 517 518 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 519 if (!fcp) 520 goto err; 521 522 if (fcp->fc_flags & FCP_CFL_LEN_MASK) 523 goto err; /* not handling longer CDBs yet */ 524 525 /* 526 * Check for FCP task management flags 527 */ 528 if (fcp->fc_tm_flags) { 529 ft_send_tm(cmd); 530 return; 531 } 532 533 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) { 534 case 0: 535 data_dir = DMA_NONE; 536 break; 537 case FCP_CFL_RDDATA: 538 data_dir = DMA_FROM_DEVICE; 539 break; 540 case FCP_CFL_WRDATA: 541 data_dir = DMA_TO_DEVICE; 542 break; 543 case FCP_CFL_WRDATA | FCP_CFL_RDDATA: 544 goto err; /* TBD not supported by tcm_fc yet */ 545 } 546 /* 547 * Locate the SAM Task Attr from fc_pri_ta 548 */ 549 switch (fcp->fc_pri_ta & FCP_PTA_MASK) { 550 case FCP_PTA_HEADQ: 551 task_attr = TCM_HEAD_TAG; 552 break; 553 case FCP_PTA_ORDERED: 554 task_attr = TCM_ORDERED_TAG; 555 break; 556 case FCP_PTA_ACA: 557 task_attr = TCM_ACA_TAG; 558 break; 559 case FCP_PTA_SIMPLE: /* Fallthrough */ 560 default: 561 task_attr = TCM_SIMPLE_TAG; 562 } 563 564 fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd); 565 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid; 566 /* 567 * Use a single se_cmd->cmd_kref as we expect to release se_cmd 568 * directly from ft_check_stop_free callback in response path. 569 */ 570 if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb, 571 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 572 ntohl(fcp->fc_dl), task_attr, data_dir, 573 TARGET_SCF_ACK_KREF | TARGET_SCF_USE_CPUID)) 574 goto err; 575 576 pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd); 577 return; 578 579 err: 580 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 581 } 582