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 transport_generic_free_cmd(se_cmd, 0); 111 return 1; 112 } 113 114 /* 115 * Send response. 116 */ 117 int ft_queue_status(struct se_cmd *se_cmd) 118 { 119 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 120 struct fc_frame *fp; 121 struct fcp_resp_with_ext *fcp; 122 struct fc_lport *lport; 123 struct fc_exch *ep; 124 size_t len; 125 int rc; 126 127 if (cmd->aborted) 128 return 0; 129 ft_dump_cmd(cmd, __func__); 130 ep = fc_seq_exch(cmd->seq); 131 lport = ep->lp; 132 len = sizeof(*fcp) + se_cmd->scsi_sense_length; 133 fp = fc_frame_alloc(lport, len); 134 if (!fp) { 135 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 136 return -ENOMEM; 137 } 138 139 fcp = fc_frame_payload_get(fp, len); 140 memset(fcp, 0, len); 141 fcp->resp.fr_status = se_cmd->scsi_status; 142 143 len = se_cmd->scsi_sense_length; 144 if (len) { 145 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL; 146 fcp->ext.fr_sns_len = htonl(len); 147 memcpy((fcp + 1), se_cmd->sense_buffer, len); 148 } 149 150 /* 151 * Test underflow and overflow with one mask. Usually both are off. 152 * Bidirectional commands are not handled yet. 153 */ 154 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) { 155 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) 156 fcp->resp.fr_flags |= FCP_RESID_OVER; 157 else 158 fcp->resp.fr_flags |= FCP_RESID_UNDER; 159 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count); 160 } 161 162 /* 163 * Send response. 164 */ 165 cmd->seq = lport->tt.seq_start_next(cmd->seq); 166 fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP, 167 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0); 168 169 rc = lport->tt.seq_send(lport, cmd->seq, fp); 170 if (rc) { 171 pr_info_ratelimited("%s: Failed to send response frame %p, " 172 "xid <0x%x>\n", __func__, fp, ep->xid); 173 /* 174 * Generate a TASK_SET_FULL status to notify the initiator 175 * to reduce it's queue_depth after the se_cmd response has 176 * been re-queued by target-core. 177 */ 178 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 179 return -ENOMEM; 180 } 181 lport->tt.exch_done(cmd->seq); 182 return 0; 183 } 184 185 int ft_write_pending_status(struct se_cmd *se_cmd) 186 { 187 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 188 189 return cmd->write_data_len != se_cmd->data_length; 190 } 191 192 /* 193 * Send TX_RDY (transfer ready). 194 */ 195 int ft_write_pending(struct se_cmd *se_cmd) 196 { 197 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 198 struct fc_frame *fp; 199 struct fcp_txrdy *txrdy; 200 struct fc_lport *lport; 201 struct fc_exch *ep; 202 struct fc_frame_header *fh; 203 u32 f_ctl; 204 205 ft_dump_cmd(cmd, __func__); 206 207 if (cmd->aborted) 208 return 0; 209 ep = fc_seq_exch(cmd->seq); 210 lport = ep->lp; 211 fp = fc_frame_alloc(lport, sizeof(*txrdy)); 212 if (!fp) 213 return -ENOMEM; /* Signal QUEUE_FULL */ 214 215 txrdy = fc_frame_payload_get(fp, sizeof(*txrdy)); 216 memset(txrdy, 0, sizeof(*txrdy)); 217 txrdy->ft_burst_len = htonl(se_cmd->data_length); 218 219 cmd->seq = lport->tt.seq_start_next(cmd->seq); 220 fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP, 221 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); 222 223 fh = fc_frame_header_get(fp); 224 f_ctl = ntoh24(fh->fh_f_ctl); 225 226 /* Only if it is 'Exchange Responder' */ 227 if (f_ctl & FC_FC_EX_CTX) { 228 /* Target is 'exchange responder' and sending XFER_READY 229 * to 'exchange initiator (initiator)' 230 */ 231 if ((ep->xid <= lport->lro_xid) && 232 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) { 233 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && 234 lport->tt.ddp_target(lport, ep->xid, 235 se_cmd->t_data_sg, 236 se_cmd->t_data_nents)) 237 cmd->was_ddp_setup = 1; 238 } 239 } 240 lport->tt.seq_send(lport, cmd->seq, fp); 241 return 0; 242 } 243 244 int ft_get_cmd_state(struct se_cmd *se_cmd) 245 { 246 return 0; 247 } 248 249 /* 250 * FC sequence response handler for follow-on sequences (data) and aborts. 251 */ 252 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg) 253 { 254 struct ft_cmd *cmd = arg; 255 struct fc_frame_header *fh; 256 257 if (IS_ERR(fp)) { 258 /* XXX need to find cmd if queued */ 259 cmd->seq = NULL; 260 cmd->aborted = true; 261 return; 262 } 263 264 fh = fc_frame_header_get(fp); 265 266 switch (fh->fh_r_ctl) { 267 case FC_RCTL_DD_SOL_DATA: /* write data */ 268 ft_recv_write_data(cmd, fp); 269 break; 270 case FC_RCTL_DD_UNSOL_CTL: /* command */ 271 case FC_RCTL_DD_SOL_CTL: /* transfer ready */ 272 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 273 default: 274 pr_debug("%s: unhandled frame r_ctl %x\n", 275 __func__, fh->fh_r_ctl); 276 ft_invl_hw_context(cmd); 277 fc_frame_free(fp); 278 transport_generic_free_cmd(&cmd->se_cmd, 0); 279 break; 280 } 281 } 282 283 /* 284 * Send a FCP response including SCSI status and optional FCP rsp_code. 285 * status is SAM_STAT_GOOD (zero) iff code is valid. 286 * This is used in error cases, such as allocation failures. 287 */ 288 static void ft_send_resp_status(struct fc_lport *lport, 289 const struct fc_frame *rx_fp, 290 u32 status, enum fcp_resp_rsp_codes code) 291 { 292 struct fc_frame *fp; 293 struct fc_seq *sp; 294 const struct fc_frame_header *fh; 295 size_t len; 296 struct fcp_resp_with_ext *fcp; 297 struct fcp_resp_rsp_info *info; 298 299 fh = fc_frame_header_get(rx_fp); 300 pr_debug("FCP error response: did %x oxid %x status %x code %x\n", 301 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code); 302 len = sizeof(*fcp); 303 if (status == SAM_STAT_GOOD) 304 len += sizeof(*info); 305 fp = fc_frame_alloc(lport, len); 306 if (!fp) 307 return; 308 fcp = fc_frame_payload_get(fp, len); 309 memset(fcp, 0, len); 310 fcp->resp.fr_status = status; 311 if (status == SAM_STAT_GOOD) { 312 fcp->ext.fr_rsp_len = htonl(sizeof(*info)); 313 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL; 314 info = (struct fcp_resp_rsp_info *)(fcp + 1); 315 info->rsp_code = code; 316 } 317 318 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0); 319 sp = fr_seq(fp); 320 if (sp) { 321 lport->tt.seq_send(lport, sp, fp); 322 lport->tt.exch_done(sp); 323 } else { 324 lport->tt.frame_send(lport, fp); 325 } 326 } 327 328 /* 329 * Send error or task management response. 330 */ 331 static void ft_send_resp_code(struct ft_cmd *cmd, 332 enum fcp_resp_rsp_codes code) 333 { 334 ft_send_resp_status(cmd->sess->tport->lport, 335 cmd->req_frame, SAM_STAT_GOOD, code); 336 } 337 338 339 /* 340 * Send error or task management response. 341 * Always frees the cmd and associated state. 342 */ 343 static void ft_send_resp_code_and_free(struct ft_cmd *cmd, 344 enum fcp_resp_rsp_codes code) 345 { 346 ft_send_resp_code(cmd, code); 347 ft_free_cmd(cmd); 348 } 349 350 /* 351 * Handle Task Management Request. 352 */ 353 static void ft_send_tm(struct ft_cmd *cmd) 354 { 355 struct fcp_cmnd *fcp; 356 int rc; 357 u8 tm_func; 358 359 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 360 361 switch (fcp->fc_tm_flags) { 362 case FCP_TMF_LUN_RESET: 363 tm_func = TMR_LUN_RESET; 364 break; 365 case FCP_TMF_TGT_RESET: 366 tm_func = TMR_TARGET_WARM_RESET; 367 break; 368 case FCP_TMF_CLR_TASK_SET: 369 tm_func = TMR_CLEAR_TASK_SET; 370 break; 371 case FCP_TMF_ABT_TASK_SET: 372 tm_func = TMR_ABORT_TASK_SET; 373 break; 374 case FCP_TMF_CLR_ACA: 375 tm_func = TMR_CLEAR_ACA; 376 break; 377 default: 378 /* 379 * FCP4r01 indicates having a combination of 380 * tm_flags set is invalid. 381 */ 382 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags); 383 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 384 return; 385 } 386 387 /* FIXME: Add referenced task tag for ABORT_TASK */ 388 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess, 389 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 390 cmd, tm_func, GFP_KERNEL, 0, 0); 391 if (rc < 0) 392 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED); 393 } 394 395 /* 396 * Send status from completed task management request. 397 */ 398 void ft_queue_tm_resp(struct se_cmd *se_cmd) 399 { 400 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 401 struct se_tmr_req *tmr = se_cmd->se_tmr_req; 402 enum fcp_resp_rsp_codes code; 403 404 if (cmd->aborted) 405 return; 406 switch (tmr->response) { 407 case TMR_FUNCTION_COMPLETE: 408 code = FCP_TMF_CMPL; 409 break; 410 case TMR_LUN_DOES_NOT_EXIST: 411 code = FCP_TMF_INVALID_LUN; 412 break; 413 case TMR_FUNCTION_REJECTED: 414 code = FCP_TMF_REJECTED; 415 break; 416 case TMR_TASK_DOES_NOT_EXIST: 417 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED: 418 default: 419 code = FCP_TMF_FAILED; 420 break; 421 } 422 pr_debug("tmr fn %d resp %d fcp code %d\n", 423 tmr->function, tmr->response, code); 424 ft_send_resp_code(cmd, code); 425 } 426 427 void ft_aborted_task(struct se_cmd *se_cmd) 428 { 429 return; 430 } 431 432 static void ft_send_work(struct work_struct *work); 433 434 /* 435 * Handle incoming FCP command. 436 */ 437 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) 438 { 439 struct ft_cmd *cmd; 440 struct fc_lport *lport = sess->tport->lport; 441 struct se_session *se_sess = sess->se_sess; 442 int tag; 443 444 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); 445 if (tag < 0) 446 goto busy; 447 448 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag]; 449 memset(cmd, 0, sizeof(struct ft_cmd)); 450 451 cmd->se_cmd.map_tag = tag; 452 cmd->sess = sess; 453 cmd->seq = lport->tt.seq_assign(lport, fp); 454 if (!cmd->seq) { 455 percpu_ida_free(&se_sess->sess_tag_pool, tag); 456 goto busy; 457 } 458 cmd->req_frame = fp; /* hold frame during cmd */ 459 460 INIT_WORK(&cmd->work, ft_send_work); 461 queue_work(sess->tport->tpg->workqueue, &cmd->work); 462 return; 463 464 busy: 465 pr_debug("cmd or seq allocation failure - sending BUSY\n"); 466 ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0); 467 fc_frame_free(fp); 468 ft_sess_put(sess); /* undo get from lookup */ 469 } 470 471 472 /* 473 * Handle incoming FCP frame. 474 * Caller has verified that the frame is type FCP. 475 */ 476 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp) 477 { 478 struct fc_frame_header *fh = fc_frame_header_get(fp); 479 480 switch (fh->fh_r_ctl) { 481 case FC_RCTL_DD_UNSOL_CMD: /* command */ 482 ft_recv_cmd(sess, fp); 483 break; 484 case FC_RCTL_DD_SOL_DATA: /* write data */ 485 case FC_RCTL_DD_UNSOL_CTL: 486 case FC_RCTL_DD_SOL_CTL: 487 case FC_RCTL_DD_DATA_DESC: /* transfer ready */ 488 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */ 489 default: 490 pr_debug("%s: unhandled frame r_ctl %x\n", 491 __func__, fh->fh_r_ctl); 492 fc_frame_free(fp); 493 ft_sess_put(sess); /* undo get from lookup */ 494 break; 495 } 496 } 497 498 /* 499 * Send new command to target. 500 */ 501 static void ft_send_work(struct work_struct *work) 502 { 503 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 504 struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame); 505 struct fcp_cmnd *fcp; 506 int data_dir = 0; 507 int task_attr; 508 509 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp)); 510 if (!fcp) 511 goto err; 512 513 if (fcp->fc_flags & FCP_CFL_LEN_MASK) 514 goto err; /* not handling longer CDBs yet */ 515 516 /* 517 * Check for FCP task management flags 518 */ 519 if (fcp->fc_tm_flags) { 520 ft_send_tm(cmd); 521 return; 522 } 523 524 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) { 525 case 0: 526 data_dir = DMA_NONE; 527 break; 528 case FCP_CFL_RDDATA: 529 data_dir = DMA_FROM_DEVICE; 530 break; 531 case FCP_CFL_WRDATA: 532 data_dir = DMA_TO_DEVICE; 533 break; 534 case FCP_CFL_WRDATA | FCP_CFL_RDDATA: 535 goto err; /* TBD not supported by tcm_fc yet */ 536 } 537 /* 538 * Locate the SAM Task Attr from fc_pri_ta 539 */ 540 switch (fcp->fc_pri_ta & FCP_PTA_MASK) { 541 case FCP_PTA_HEADQ: 542 task_attr = TCM_HEAD_TAG; 543 break; 544 case FCP_PTA_ORDERED: 545 task_attr = TCM_ORDERED_TAG; 546 break; 547 case FCP_PTA_ACA: 548 task_attr = TCM_ACA_TAG; 549 break; 550 case FCP_PTA_SIMPLE: /* Fallthrough */ 551 default: 552 task_attr = TCM_SIMPLE_TAG; 553 } 554 555 fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd); 556 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid; 557 /* 558 * Use a single se_cmd->cmd_kref as we expect to release se_cmd 559 * directly from ft_check_stop_free callback in response path. 560 */ 561 if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb, 562 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun), 563 ntohl(fcp->fc_dl), task_attr, data_dir, 0)) 564 goto err; 565 566 pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl); 567 return; 568 569 err: 570 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID); 571 } 572