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 */
_ft_dump_cmd(struct ft_cmd * cmd,const char * caller)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
ft_dump_cmd(struct ft_cmd * cmd,const char * caller)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
ft_free_cmd(struct ft_cmd * cmd)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
ft_release_cmd(struct se_cmd * se_cmd)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
ft_check_stop_free(struct se_cmd * se_cmd)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 */
ft_queue_status(struct se_cmd * se_cmd)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
ft_write_pending_status(struct se_cmd * se_cmd)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 */
ft_write_pending(struct se_cmd * se_cmd)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 = fc_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 fc_seq_send(lport, cmd->seq, fp);
243 return 0;
244 }
245
ft_get_cmd_state(struct se_cmd * se_cmd)246 int ft_get_cmd_state(struct se_cmd *se_cmd)
247 {
248 return 0;
249 }
250
251 /*
252 * FC sequence response handler for follow-on sequences (data) and aborts.
253 */
ft_recv_seq(struct fc_seq * sp,struct fc_frame * fp,void * arg)254 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
255 {
256 struct ft_cmd *cmd = arg;
257 struct fc_frame_header *fh;
258
259 if (IS_ERR(fp)) {
260 /* XXX need to find cmd if queued */
261 cmd->seq = NULL;
262 cmd->aborted = true;
263 return;
264 }
265
266 fh = fc_frame_header_get(fp);
267
268 switch (fh->fh_r_ctl) {
269 case FC_RCTL_DD_SOL_DATA: /* write data */
270 ft_recv_write_data(cmd, fp);
271 break;
272 case FC_RCTL_DD_UNSOL_CTL: /* command */
273 case FC_RCTL_DD_SOL_CTL: /* transfer ready */
274 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
275 default:
276 pr_debug("%s: unhandled frame r_ctl %x\n",
277 __func__, fh->fh_r_ctl);
278 ft_invl_hw_context(cmd);
279 fc_frame_free(fp);
280 transport_generic_free_cmd(&cmd->se_cmd, 0);
281 break;
282 }
283 }
284
285 /*
286 * Send a FCP response including SCSI status and optional FCP rsp_code.
287 * status is SAM_STAT_GOOD (zero) iff code is valid.
288 * This is used in error cases, such as allocation failures.
289 */
ft_send_resp_status(struct fc_lport * lport,const struct fc_frame * rx_fp,u32 status,enum fcp_resp_rsp_codes code)290 static void ft_send_resp_status(struct fc_lport *lport,
291 const struct fc_frame *rx_fp,
292 u32 status, enum fcp_resp_rsp_codes code)
293 {
294 struct fc_frame *fp;
295 struct fc_seq *sp;
296 const struct fc_frame_header *fh;
297 size_t len;
298 struct fcp_resp_with_ext *fcp;
299 struct fcp_resp_rsp_info *info;
300
301 fh = fc_frame_header_get(rx_fp);
302 pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
303 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
304 len = sizeof(*fcp);
305 if (status == SAM_STAT_GOOD)
306 len += sizeof(*info);
307 fp = fc_frame_alloc(lport, len);
308 if (!fp)
309 return;
310 fcp = fc_frame_payload_get(fp, len);
311 memset(fcp, 0, len);
312 fcp->resp.fr_status = status;
313 if (status == SAM_STAT_GOOD) {
314 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
315 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
316 info = (struct fcp_resp_rsp_info *)(fcp + 1);
317 info->rsp_code = code;
318 }
319
320 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
321 sp = fr_seq(fp);
322 if (sp) {
323 fc_seq_send(lport, sp, fp);
324 fc_exch_done(sp);
325 } else {
326 lport->tt.frame_send(lport, fp);
327 }
328 }
329
330 /*
331 * Send error or task management response.
332 */
ft_send_resp_code(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)333 static void ft_send_resp_code(struct ft_cmd *cmd,
334 enum fcp_resp_rsp_codes code)
335 {
336 ft_send_resp_status(cmd->sess->tport->lport,
337 cmd->req_frame, SAM_STAT_GOOD, code);
338 }
339
340
341 /*
342 * Send error or task management response.
343 * Always frees the cmd and associated state.
344 */
ft_send_resp_code_and_free(struct ft_cmd * cmd,enum fcp_resp_rsp_codes code)345 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
346 enum fcp_resp_rsp_codes code)
347 {
348 ft_send_resp_code(cmd, code);
349 ft_free_cmd(cmd);
350 }
351
352 /*
353 * Handle Task Management Request.
354 */
ft_send_tm(struct ft_cmd * cmd)355 static void ft_send_tm(struct ft_cmd *cmd)
356 {
357 struct fcp_cmnd *fcp;
358 int rc;
359 u8 tm_func;
360
361 fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
362
363 switch (fcp->fc_tm_flags) {
364 case FCP_TMF_LUN_RESET:
365 tm_func = TMR_LUN_RESET;
366 break;
367 case FCP_TMF_TGT_RESET:
368 tm_func = TMR_TARGET_WARM_RESET;
369 break;
370 case FCP_TMF_CLR_TASK_SET:
371 tm_func = TMR_CLEAR_TASK_SET;
372 break;
373 case FCP_TMF_ABT_TASK_SET:
374 tm_func = TMR_ABORT_TASK_SET;
375 break;
376 case FCP_TMF_CLR_ACA:
377 tm_func = TMR_CLEAR_ACA;
378 break;
379 default:
380 /*
381 * FCP4r01 indicates having a combination of
382 * tm_flags set is invalid.
383 */
384 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
385 ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
386 return;
387 }
388
389 /* FIXME: Add referenced task tag for ABORT_TASK */
390 rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
391 &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
392 cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
393 if (rc < 0)
394 ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
395 }
396
397 /*
398 * Send status from completed task management request.
399 */
ft_queue_tm_resp(struct se_cmd * se_cmd)400 void ft_queue_tm_resp(struct se_cmd *se_cmd)
401 {
402 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
403 struct se_tmr_req *tmr = se_cmd->se_tmr_req;
404 enum fcp_resp_rsp_codes code;
405
406 if (cmd->aborted)
407 return;
408 switch (tmr->response) {
409 case TMR_FUNCTION_COMPLETE:
410 code = FCP_TMF_CMPL;
411 break;
412 case TMR_LUN_DOES_NOT_EXIST:
413 code = FCP_TMF_INVALID_LUN;
414 break;
415 case TMR_FUNCTION_REJECTED:
416 code = FCP_TMF_REJECTED;
417 break;
418 case TMR_TASK_DOES_NOT_EXIST:
419 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
420 default:
421 code = FCP_TMF_FAILED;
422 break;
423 }
424 pr_debug("tmr fn %d resp %d fcp code %d\n",
425 tmr->function, tmr->response, code);
426 ft_send_resp_code(cmd, code);
427 /*
428 * Drop the extra ACK_KREF reference taken by target_submit_tmr()
429 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
430 * final se_cmd->cmd_kref put.
431 */
432 target_put_sess_cmd(&cmd->se_cmd);
433 }
434
ft_aborted_task(struct se_cmd * se_cmd)435 void ft_aborted_task(struct se_cmd *se_cmd)
436 {
437 return;
438 }
439
440 static void ft_send_work(struct work_struct *work);
441
442 /*
443 * Handle incoming FCP command.
444 */
ft_recv_cmd(struct ft_sess * sess,struct fc_frame * fp)445 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
446 {
447 struct ft_cmd *cmd;
448 struct fc_lport *lport = sess->tport->lport;
449 struct se_session *se_sess = sess->se_sess;
450 int tag, cpu;
451
452 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
453 if (tag < 0)
454 goto busy;
455
456 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
457 memset(cmd, 0, sizeof(struct ft_cmd));
458
459 cmd->se_cmd.map_tag = tag;
460 cmd->se_cmd.map_cpu = cpu;
461 cmd->sess = sess;
462 cmd->seq = fc_seq_assign(lport, fp);
463 if (!cmd->seq) {
464 target_free_tag(se_sess, &cmd->se_cmd);
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 */
ft_recv_req(struct ft_sess * sess,struct fc_frame * fp)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 */
ft_send_work(struct work_struct * work)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
