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 <asm/unaligned.h> 32 #include <scsi/scsi_tcq.h> 33 #include <scsi/libfc.h> 34 #include <scsi/fc_encode.h> 35 36 #include <target/target_core_base.h> 37 #include <target/target_core_fabric.h> 38 39 #include "tcm_fc.h" 40 41 /* 42 * Dump cmd state for debugging. 43 */ 44 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 45 { 46 struct fc_exch *ep; 47 struct fc_seq *sp; 48 struct se_cmd *se_cmd; 49 struct scatterlist *sg; 50 int count; 51 52 se_cmd = &cmd->se_cmd; 53 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n", 54 caller, cmd, cmd->sess, cmd->seq, se_cmd); 55 56 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n", 57 caller, cmd, se_cmd->t_data_nents, 58 se_cmd->data_length, se_cmd->se_cmd_flags); 59 60 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count) 61 pr_debug("%s: cmd %p sg %p page %p " 62 "len 0x%x off 0x%x\n", 63 caller, cmd, sg, 64 sg_page(sg), sg->length, sg->offset); 65 66 sp = cmd->seq; 67 if (sp) { 68 ep = fc_seq_exch(sp); 69 pr_debug("%s: cmd %p sid %x did %x " 70 "ox_id %x rx_id %x seq_id %x e_stat %x\n", 71 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid, 72 sp->id, ep->esb_stat); 73 } 74 } 75 76 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller) 77 { 78 if (unlikely(ft_debug_logging)) 79 _ft_dump_cmd(cmd, caller); 80 } 81 82 static void ft_free_cmd(struct ft_cmd *cmd) 83 { 84 struct fc_frame *fp; 85 struct ft_sess *sess; 86 87 if (!cmd) 88 return; 89 sess = cmd->sess; 90 fp = cmd->req_frame; 91 if (fr_seq(fp)) 92 fc_seq_release(fr_seq(fp)); 93 fc_frame_free(fp); 94 target_free_tag(sess->se_sess, &cmd->se_cmd); 95 ft_sess_put(sess); /* undo get from lookup at recv */ 96 } 97 98 void ft_release_cmd(struct se_cmd *se_cmd) 99 { 100 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 101 102 ft_free_cmd(cmd); 103 } 104 105 int ft_check_stop_free(struct se_cmd *se_cmd) 106 { 107 return transport_generic_free_cmd(se_cmd, 0); 108 } 109 110 /* 111 * Send response. 112 */ 113 int ft_queue_status(struct se_cmd *se_cmd) 114 { 115 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 116 struct fc_frame *fp; 117 struct fcp_resp_with_ext *fcp; 118 struct fc_lport *lport; 119 struct fc_exch *ep; 120 size_t len; 121 int rc; 122 123 if (cmd->aborted) 124 return 0; 125 ft_dump_cmd(cmd, __func__); 126 ep = fc_seq_exch(cmd->seq); 127 lport = ep->lp; 128 len = sizeof(*fcp) + se_cmd->scsi_sense_length; 129 fp = fc_frame_alloc(lport, len); 130 if (!fp) { 131 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 132 return -ENOMEM; 133 } 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 = fc_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 rc = fc_seq_send(lport, cmd->seq, fp); 166 if (rc) { 167 pr_info_ratelimited("%s: Failed to send response frame %p, " 168 "xid <0x%x>\n", __func__, fp, ep->xid); 169 /* 170 * Generate a TASK_SET_FULL status to notify the initiator 171 * to reduce it's queue_depth after the se_cmd response has 172 * been re-queued by target-core. 173 */ 174 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 175 return -ENOMEM; 176 } 177 fc_exch_done(cmd->seq); 178 /* 179 * Drop the extra ACK_KREF reference taken by target_submit_cmd() 180 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 181 * final se_cmd->cmd_kref put. 182 */ 183 target_put_sess_cmd(&cmd->se_cmd); 184 return 0; 185 } 186 187 /* 188 * Send TX_RDY (transfer ready). 189 */ 190 int ft_write_pending(struct se_cmd *se_cmd) 191 { 192 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 193 struct fc_frame *fp; 194 struct fcp_txrdy *txrdy; 195 struct fc_lport *lport; 196 struct fc_exch *ep; 197 struct fc_frame_header *fh; 198 u32 f_ctl; 199 200 ft_dump_cmd(cmd, __func__); 201 202 if (cmd->aborted) 203 return 0; 204 ep = fc_seq_exch(cmd->seq); 205 lport = ep->lp; 206 fp = fc_frame_alloc(lport, sizeof(*txrdy)); 207 if (!fp) 208 return -ENOMEM; /* Signal QUEUE_FULL */ 209 210 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy)); 211 memset(txrdy, 0, sizeof(*txrdy)); 212 txrdy->ft_burst_len = htonl(se_cmd->data_length); 213 214 cmd->seq = fc_seq_start_next(cmd->seq); 215 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP, 216 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); 217 218 fh = fc_frame_header_get(fp); 219 f_ctl = ntoh24(fh->fh_f_ctl); 220 221 /* Only if it is 'Exchange Responder' */ 222 if (f_ctl & FC_FC_EX_CTX) { 223 /* Target is 'exchange responder' and sending XFER_READY 224 * to 'exchange initiator (initiator)' 225 */ 226 if ((ep->xid <= lport->lro_xid) && 227 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) { 228 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && 229 lport->tt.ddp_target(lport, ep->xid, 230 se_cmd->t_data_sg, 231 se_cmd->t_data_nents)) 232 cmd->was_ddp_setup = 1; 233 } 234 } 235 fc_seq_send(lport, cmd->seq, fp); 236 return 0; 237 } 238 239 int ft_get_cmd_state(struct se_cmd *se_cmd) 240 { 241 return 0; 242 } 243 244 /* 245 * FC sequence response handler for follow-on sequences (data) and aborts. 246 */ 247 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg) 248 { 249 struct ft_cmd *cmd = arg; 250 struct fc_frame_header *fh; 251 252 if (IS_ERR(fp)) { 253 /* XXX need to find cmd if queued */ 254 cmd->seq = NULL; 255 cmd->aborted = true; 256 return; 257 } 258 259 fh = fc_frame_header_get(fp); 260 261 switch (fh->fh_r_ctl) { 262 case FC_RCTL_DD_SOL_DATA: /* write data */ 263 ft_recv_write_data(cmd, fp); 264 break; 265 case FC_RCTL_DD_UNSOL_CTL: /* command */ 266 case FC_RCTL_DD_SOL_CTL: /* transfer ready */ 267 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 268 default: 269 pr_debug("%s: unhandled frame r_ctl %x\n", 270 __func__, fh->fh_r_ctl); 271 ft_invl_hw_context(cmd); 272 fc_frame_free(fp); 273 transport_generic_free_cmd(&cmd->se_cmd, 0); 274 break; 275 } 276 } 277 278 /* 279 * Send a FCP response including SCSI status and optional FCP rsp_code. 280 * status is SAM_STAT_GOOD (zero) iff code is valid. 281 * This is used in error cases, such as allocation failures. 282 */ 283 static void ft_send_resp_status(struct fc_lport *lport, 284 const struct fc_frame *rx_fp, 285 u32 status, enum fcp_resp_rsp_codes code) 286 { 287 struct fc_frame *fp; 288 struct fc_seq *sp; 289 const struct fc_frame_header *fh; 290 size_t len; 291 struct fcp_resp_with_ext *fcp; 292 struct fcp_resp_rsp_info *info; 293 294 fh = fc_frame_header_get(rx_fp); 295 pr_debug("FCP error response: did %x oxid %x status %x code %x\n", 296 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code); 297 len = sizeof(*fcp); 298 if (status == SAM_STAT_GOOD) 299 len += sizeof(*info); 300 fp = fc_frame_alloc(lport, len); 301 if (!fp) 302 return; 303 fcp = fc_frame_payload_get(fp, len); 304 memset(fcp, 0, len); 305 fcp->resp.fr_status = status; 306 if (status == SAM_STAT_GOOD) { 307 fcp->ext.fr_rsp_len = htonl(sizeof(*info)); 308 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL; 309 info = (struct fcp_resp_rsp_info *)(fcp + 1); 310 info->rsp_code = code; 311 } 312 313 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0); 314 sp = fr_seq(fp); 315 if (sp) { 316 fc_seq_send(lport, sp, fp); 317 fc_exch_done(sp); 318 } else { 319 lport->tt.frame_send(lport, fp); 320 } 321 } 322 323 /* 324 * Send error or task management response. 325 */ 326 static void ft_send_resp_code(struct ft_cmd *cmd, 327 enum fcp_resp_rsp_codes code) 328 { 329 ft_send_resp_status(cmd->sess->tport->lport, 330 cmd->req_frame, SAM_STAT_GOOD, code); 331 } 332 333 334 /* 335 * Send error or task management response. 336 * Always frees the cmd and associated state. 337 */ 338 static void ft_send_resp_code_and_free(struct ft_cmd *cmd, 339 enum fcp_resp_rsp_codes code) 340 { 341 ft_send_resp_code(cmd, code); 342 ft_free_cmd(cmd); 343 } 344 345 /* 346 * Handle Task Management Request. 347 */ 348 static void ft_send_tm(struct ft_cmd *cmd) 349 { 350 struct fcp_cmnd *fcp; 351 int rc; 352 u8 tm_func; 353 354 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 355 356 switch (fcp->fc_tm_flags) { 357 case FCP_TMF_LUN_RESET: 358 tm_func = TMR_LUN_RESET; 359 break; 360 case FCP_TMF_TGT_RESET: 361 tm_func = TMR_TARGET_WARM_RESET; 362 break; 363 case FCP_TMF_CLR_TASK_SET: 364 tm_func = TMR_CLEAR_TASK_SET; 365 break; 366 case FCP_TMF_ABT_TASK_SET: 367 tm_func = TMR_ABORT_TASK_SET; 368 break; 369 case FCP_TMF_CLR_ACA: 370 tm_func = TMR_CLEAR_ACA; 371 break; 372 default: 373 /* 374 * FCP4r01 indicates having a combination of 375 * tm_flags set is invalid. 376 */ 377 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags); 378 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 379 return; 380 } 381 382 /* FIXME: Add referenced task tag for ABORT_TASK */ 383 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess, 384 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 385 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF); 386 if (rc < 0) 387 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED); 388 } 389 390 /* 391 * Send status from completed task management request. 392 */ 393 void ft_queue_tm_resp(struct se_cmd *se_cmd) 394 { 395 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 396 struct se_tmr_req *tmr = se_cmd->se_tmr_req; 397 enum fcp_resp_rsp_codes code; 398 399 if (cmd->aborted) 400 return; 401 switch (tmr->response) { 402 case TMR_FUNCTION_COMPLETE: 403 code = FCP_TMF_CMPL; 404 break; 405 case TMR_LUN_DOES_NOT_EXIST: 406 code = FCP_TMF_INVALID_LUN; 407 break; 408 case TMR_FUNCTION_REJECTED: 409 code = FCP_TMF_REJECTED; 410 break; 411 case TMR_TASK_DOES_NOT_EXIST: 412 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED: 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 /* 421 * Drop the extra ACK_KREF reference taken by target_submit_tmr() 422 * ahead of ft_check_stop_free() -> transport_generic_free_cmd() 423 * final se_cmd->cmd_kref put. 424 */ 425 target_put_sess_cmd(&cmd->se_cmd); 426 } 427 428 void ft_aborted_task(struct se_cmd *se_cmd) 429 { 430 return; 431 } 432 433 static void ft_send_work(struct work_struct *work); 434 435 /* 436 * Handle incoming FCP command. 437 */ 438 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) 439 { 440 struct ft_cmd *cmd; 441 struct fc_lport *lport = sess->tport->lport; 442 struct se_session *se_sess = sess->se_sess; 443 int tag, cpu; 444 445 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); 446 if (tag < 0) 447 goto busy; 448 449 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag]; 450 memset(cmd, 0, sizeof(struct ft_cmd)); 451 452 cmd->se_cmd.map_tag = tag; 453 cmd->se_cmd.map_cpu = cpu; 454 cmd->sess = sess; 455 cmd->seq = fc_seq_assign(lport, fp); 456 if (!cmd->seq) { 457 target_free_tag(se_sess, &cmd->se_cmd); 458 goto busy; 459 } 460 cmd->req_frame = fp; /* hold frame during cmd */ 461 462 INIT_WORK(&cmd->work, ft_send_work); 463 queue_work(sess->tport->tpg->workqueue, &cmd->work); 464 return; 465 466 busy: 467 pr_debug("cmd or seq allocation failure - sending BUSY\n"); 468 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0); 469 fc_frame_free(fp); 470 ft_sess_put(sess); /* undo get from lookup */ 471 } 472 473 474 /* 475 * Handle incoming FCP frame. 476 * Caller has verified that the frame is type FCP. 477 */ 478 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp) 479 { 480 struct fc_frame_header *fh = fc_frame_header_get(fp); 481 482 switch (fh->fh_r_ctl) { 483 case FC_RCTL_DD_UNSOL_CMD: /* command */ 484 ft_recv_cmd(sess, fp); 485 break; 486 case FC_RCTL_DD_SOL_DATA: /* write data */ 487 case FC_RCTL_DD_UNSOL_CTL: 488 case FC_RCTL_DD_SOL_CTL: 489 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 490 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */ 491 default: 492 pr_debug("%s: unhandled frame r_ctl %x\n", 493 __func__, fh->fh_r_ctl); 494 fc_frame_free(fp); 495 ft_sess_put(sess); /* undo get from lookup */ 496 break; 497 } 498 } 499 500 /* 501 * Send new command to target. 502 */ 503 static void ft_send_work(struct work_struct *work) 504 { 505 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 506 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame); 507 struct fcp_cmnd *fcp; 508 int data_dir = 0; 509 int task_attr; 510 511 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 512 if (!fcp) 513 goto err; 514 515 if (fcp->fc_flags & FCP_CFL_LEN_MASK) 516 goto err; /* not handling longer CDBs yet */ 517 518 /* 519 * Check for FCP task management flags 520 */ 521 if (fcp->fc_tm_flags) { 522 ft_send_tm(cmd); 523 return; 524 } 525 526 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) { 527 case 0: 528 data_dir = DMA_NONE; 529 break; 530 case FCP_CFL_RDDATA: 531 data_dir = DMA_FROM_DEVICE; 532 break; 533 case FCP_CFL_WRDATA: 534 data_dir = DMA_TO_DEVICE; 535 break; 536 case FCP_CFL_WRDATA | FCP_CFL_RDDATA: 537 goto err; /* TBD not supported by tcm_fc yet */ 538 } 539 /* 540 * Locate the SAM Task Attr from fc_pri_ta 541 */ 542 switch (fcp->fc_pri_ta & FCP_PTA_MASK) { 543 case FCP_PTA_HEADQ: 544 task_attr = TCM_HEAD_TAG; 545 break; 546 case FCP_PTA_ORDERED: 547 task_attr = TCM_ORDERED_TAG; 548 break; 549 case FCP_PTA_ACA: 550 task_attr = TCM_ACA_TAG; 551 break; 552 case FCP_PTA_SIMPLE: /* Fallthrough */ 553 default: 554 task_attr = TCM_SIMPLE_TAG; 555 } 556 557 fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd); 558 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid; 559 /* 560 * Use a single se_cmd->cmd_kref as we expect to release se_cmd 561 * directly from ft_check_stop_free callback in response path. 562 */ 563 if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb, 564 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 565 ntohl(fcp->fc_dl), task_attr, data_dir, 566 TARGET_SCF_ACK_KREF | TARGET_SCF_USE_CPUID)) 567 goto err; 568 569 pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd); 570 return; 571 572 err: 573 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 574 } 575