xref: /openbmc/linux/drivers/target/tcm_fc/tfc_cmd.c (revision 0da85d1e) 
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.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_cmnd.h>
37 #include <scsi/scsi_tcq.h>
38 #include <scsi/libfc.h>
39 #include <scsi/fc_encode.h>
40 
41 #include <target/target_core_base.h>
42 #include <target/target_core_fabric.h>
43 #include <target/target_core_configfs.h>
44 #include <target/configfs_macros.h>
45 
46 #include "tcm_fc.h"
47 
48 /*
49  * Dump cmd state for debugging.
50  */
51 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
52 {
53 	struct fc_exch *ep;
54 	struct fc_seq *sp;
55 	struct se_cmd *se_cmd;
56 	struct scatterlist *sg;
57 	int count;
58 
59 	se_cmd = &cmd->se_cmd;
60 	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
61 		caller, cmd, cmd->sess, cmd->seq, se_cmd);
62 
63 	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
64 		caller, cmd, se_cmd->t_data_nents,
65 	       se_cmd->data_length, se_cmd->se_cmd_flags);
66 
67 	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
68 		pr_debug("%s: cmd %p sg %p page %p "
69 			"len 0x%x off 0x%x\n",
70 			caller, cmd, sg,
71 			sg_page(sg), sg->length, sg->offset);
72 
73 	sp = cmd->seq;
74 	if (sp) {
75 		ep = fc_seq_exch(sp);
76 		pr_debug("%s: cmd %p sid %x did %x "
77 			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
78 			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
79 			sp->id, ep->esb_stat);
80 	}
81 }
82 
83 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
84 {
85 	if (unlikely(ft_debug_logging))
86 		_ft_dump_cmd(cmd, caller);
87 }
88 
89 static void ft_free_cmd(struct ft_cmd *cmd)
90 {
91 	struct fc_frame *fp;
92 	struct fc_lport *lport;
93 	struct ft_sess *sess;
94 
95 	if (!cmd)
96 		return;
97 	sess = cmd->sess;
98 	fp = cmd->req_frame;
99 	lport = fr_dev(fp);
100 	if (fr_seq(fp))
101 		lport->tt.seq_release(fr_seq(fp));
102 	fc_frame_free(fp);
103 	percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
104 	ft_sess_put(sess);	/* undo get from lookup at recv */
105 }
106 
107 void ft_release_cmd(struct se_cmd *se_cmd)
108 {
109 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
110 
111 	ft_free_cmd(cmd);
112 }
113 
114 int ft_check_stop_free(struct se_cmd *se_cmd)
115 {
116 	transport_generic_free_cmd(se_cmd, 0);
117 	return 1;
118 }
119 
120 /*
121  * Send response.
122  */
123 int ft_queue_status(struct se_cmd *se_cmd)
124 {
125 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
126 	struct fc_frame *fp;
127 	struct fcp_resp_with_ext *fcp;
128 	struct fc_lport *lport;
129 	struct fc_exch *ep;
130 	size_t len;
131 	int rc;
132 
133 	if (cmd->aborted)
134 		return 0;
135 	ft_dump_cmd(cmd, __func__);
136 	ep = fc_seq_exch(cmd->seq);
137 	lport = ep->lp;
138 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
139 	fp = fc_frame_alloc(lport, len);
140 	if (!fp) {
141 		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
142 		return -ENOMEM;
143 	}
144 
145 	fcp = fc_frame_payload_get(fp, len);
146 	memset(fcp, 0, len);
147 	fcp->resp.fr_status = se_cmd->scsi_status;
148 
149 	len = se_cmd->scsi_sense_length;
150 	if (len) {
151 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
152 		fcp->ext.fr_sns_len = htonl(len);
153 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
154 	}
155 
156 	/*
157 	 * Test underflow and overflow with one mask.  Usually both are off.
158 	 * Bidirectional commands are not handled yet.
159 	 */
160 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
161 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
162 			fcp->resp.fr_flags |= FCP_RESID_OVER;
163 		else
164 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
165 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
166 	}
167 
168 	/*
169 	 * Send response.
170 	 */
171 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
172 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
173 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
174 
175 	rc = lport->tt.seq_send(lport, cmd->seq, fp);
176 	if (rc) {
177 		pr_info_ratelimited("%s: Failed to send response frame %p, "
178 				    "xid <0x%x>\n", __func__, fp, ep->xid);
179 		/*
180 		 * Generate a TASK_SET_FULL status to notify the initiator
181 		 * to reduce it's queue_depth after the se_cmd response has
182 		 * been re-queued by target-core.
183 		 */
184 		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
185 		return -ENOMEM;
186 	}
187 	lport->tt.exch_done(cmd->seq);
188 	return 0;
189 }
190 
191 int ft_write_pending_status(struct se_cmd *se_cmd)
192 {
193 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
194 
195 	return cmd->write_data_len != se_cmd->data_length;
196 }
197 
198 /*
199  * Send TX_RDY (transfer ready).
200  */
201 int ft_write_pending(struct se_cmd *se_cmd)
202 {
203 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
204 	struct fc_frame *fp;
205 	struct fcp_txrdy *txrdy;
206 	struct fc_lport *lport;
207 	struct fc_exch *ep;
208 	struct fc_frame_header *fh;
209 	u32 f_ctl;
210 
211 	ft_dump_cmd(cmd, __func__);
212 
213 	if (cmd->aborted)
214 		return 0;
215 	ep = fc_seq_exch(cmd->seq);
216 	lport = ep->lp;
217 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
218 	if (!fp)
219 		return -ENOMEM; /* Signal QUEUE_FULL */
220 
221 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
222 	memset(txrdy, 0, sizeof(*txrdy));
223 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
224 
225 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
226 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
227 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
228 
229 	fh = fc_frame_header_get(fp);
230 	f_ctl = ntoh24(fh->fh_f_ctl);
231 
232 	/* Only if it is 'Exchange Responder' */
233 	if (f_ctl & FC_FC_EX_CTX) {
234 		/* Target is 'exchange responder' and sending XFER_READY
235 		 * to 'exchange initiator (initiator)'
236 		 */
237 		if ((ep->xid <= lport->lro_xid) &&
238 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
239 			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
240 			    lport->tt.ddp_target(lport, ep->xid,
241 						 se_cmd->t_data_sg,
242 						 se_cmd->t_data_nents))
243 				cmd->was_ddp_setup = 1;
244 		}
245 	}
246 	lport->tt.seq_send(lport, cmd->seq, fp);
247 	return 0;
248 }
249 
250 u32 ft_get_task_tag(struct se_cmd *se_cmd)
251 {
252 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
253 
254 	if (cmd->aborted)
255 		return ~0;
256 	return fc_seq_exch(cmd->seq)->rxid;
257 }
258 
259 int ft_get_cmd_state(struct se_cmd *se_cmd)
260 {
261 	return 0;
262 }
263 
264 /*
265  * FC sequence response handler for follow-on sequences (data) and aborts.
266  */
267 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
268 {
269 	struct ft_cmd *cmd = arg;
270 	struct fc_frame_header *fh;
271 
272 	if (unlikely(IS_ERR(fp))) {
273 		/* XXX need to find cmd if queued */
274 		cmd->seq = NULL;
275 		cmd->aborted = true;
276 		return;
277 	}
278 
279 	fh = fc_frame_header_get(fp);
280 
281 	switch (fh->fh_r_ctl) {
282 	case FC_RCTL_DD_SOL_DATA:	/* write data */
283 		ft_recv_write_data(cmd, fp);
284 		break;
285 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
286 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
287 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
288 	default:
289 		pr_debug("%s: unhandled frame r_ctl %x\n",
290 		       __func__, fh->fh_r_ctl);
291 		ft_invl_hw_context(cmd);
292 		fc_frame_free(fp);
293 		transport_generic_free_cmd(&cmd->se_cmd, 0);
294 		break;
295 	}
296 }
297 
298 /*
299  * Send a FCP response including SCSI status and optional FCP rsp_code.
300  * status is SAM_STAT_GOOD (zero) iff code is valid.
301  * This is used in error cases, such as allocation failures.
302  */
303 static void ft_send_resp_status(struct fc_lport *lport,
304 				const struct fc_frame *rx_fp,
305 				u32 status, enum fcp_resp_rsp_codes code)
306 {
307 	struct fc_frame *fp;
308 	struct fc_seq *sp;
309 	const struct fc_frame_header *fh;
310 	size_t len;
311 	struct fcp_resp_with_ext *fcp;
312 	struct fcp_resp_rsp_info *info;
313 
314 	fh = fc_frame_header_get(rx_fp);
315 	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
316 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
317 	len = sizeof(*fcp);
318 	if (status == SAM_STAT_GOOD)
319 		len += sizeof(*info);
320 	fp = fc_frame_alloc(lport, len);
321 	if (!fp)
322 		return;
323 	fcp = fc_frame_payload_get(fp, len);
324 	memset(fcp, 0, len);
325 	fcp->resp.fr_status = status;
326 	if (status == SAM_STAT_GOOD) {
327 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
328 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
329 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
330 		info->rsp_code = code;
331 	}
332 
333 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
334 	sp = fr_seq(fp);
335 	if (sp) {
336 		lport->tt.seq_send(lport, sp, fp);
337 		lport->tt.exch_done(sp);
338 	} else {
339 		lport->tt.frame_send(lport, fp);
340 	}
341 }
342 
343 /*
344  * Send error or task management response.
345  */
346 static void ft_send_resp_code(struct ft_cmd *cmd,
347 			      enum fcp_resp_rsp_codes code)
348 {
349 	ft_send_resp_status(cmd->sess->tport->lport,
350 			    cmd->req_frame, SAM_STAT_GOOD, code);
351 }
352 
353 
354 /*
355  * Send error or task management response.
356  * Always frees the cmd and associated state.
357  */
358 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
359 				      enum fcp_resp_rsp_codes code)
360 {
361 	ft_send_resp_code(cmd, code);
362 	ft_free_cmd(cmd);
363 }
364 
365 /*
366  * Handle Task Management Request.
367  */
368 static void ft_send_tm(struct ft_cmd *cmd)
369 {
370 	struct fcp_cmnd *fcp;
371 	int rc;
372 	u8 tm_func;
373 
374 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
375 
376 	switch (fcp->fc_tm_flags) {
377 	case FCP_TMF_LUN_RESET:
378 		tm_func = TMR_LUN_RESET;
379 		break;
380 	case FCP_TMF_TGT_RESET:
381 		tm_func = TMR_TARGET_WARM_RESET;
382 		break;
383 	case FCP_TMF_CLR_TASK_SET:
384 		tm_func = TMR_CLEAR_TASK_SET;
385 		break;
386 	case FCP_TMF_ABT_TASK_SET:
387 		tm_func = TMR_ABORT_TASK_SET;
388 		break;
389 	case FCP_TMF_CLR_ACA:
390 		tm_func = TMR_CLEAR_ACA;
391 		break;
392 	default:
393 		/*
394 		 * FCP4r01 indicates having a combination of
395 		 * tm_flags set is invalid.
396 		 */
397 		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
398 		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
399 		return;
400 	}
401 
402 	/* FIXME: Add referenced task tag for ABORT_TASK */
403 	rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
404 		&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
405 		cmd, tm_func, GFP_KERNEL, 0, 0);
406 	if (rc < 0)
407 		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
408 }
409 
410 /*
411  * Send status from completed task management request.
412  */
413 void ft_queue_tm_resp(struct se_cmd *se_cmd)
414 {
415 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
416 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
417 	enum fcp_resp_rsp_codes code;
418 
419 	if (cmd->aborted)
420 		return;
421 	switch (tmr->response) {
422 	case TMR_FUNCTION_COMPLETE:
423 		code = FCP_TMF_CMPL;
424 		break;
425 	case TMR_LUN_DOES_NOT_EXIST:
426 		code = FCP_TMF_INVALID_LUN;
427 		break;
428 	case TMR_FUNCTION_REJECTED:
429 		code = FCP_TMF_REJECTED;
430 		break;
431 	case TMR_TASK_DOES_NOT_EXIST:
432 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
433 	default:
434 		code = FCP_TMF_FAILED;
435 		break;
436 	}
437 	pr_debug("tmr fn %d resp %d fcp code %d\n",
438 		  tmr->function, tmr->response, code);
439 	ft_send_resp_code(cmd, code);
440 }
441 
442 void ft_aborted_task(struct se_cmd *se_cmd)
443 {
444 	return;
445 }
446 
447 static void ft_send_work(struct work_struct *work);
448 
449 /*
450  * Handle incoming FCP command.
451  */
452 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
453 {
454 	struct ft_cmd *cmd;
455 	struct fc_lport *lport = sess->tport->lport;
456 	struct se_session *se_sess = sess->se_sess;
457 	int tag;
458 
459 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
460 	if (tag < 0)
461 		goto busy;
462 
463 	cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
464 	memset(cmd, 0, sizeof(struct ft_cmd));
465 
466 	cmd->se_cmd.map_tag = tag;
467 	cmd->sess = sess;
468 	cmd->seq = lport->tt.seq_assign(lport, fp);
469 	if (!cmd->seq) {
470 		percpu_ida_free(&se_sess->sess_tag_pool, tag);
471 		goto busy;
472 	}
473 	cmd->req_frame = fp;		/* hold frame during cmd */
474 
475 	INIT_WORK(&cmd->work, ft_send_work);
476 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
477 	return;
478 
479 busy:
480 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
481 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
482 	fc_frame_free(fp);
483 	ft_sess_put(sess);		/* undo get from lookup */
484 }
485 
486 
487 /*
488  * Handle incoming FCP frame.
489  * Caller has verified that the frame is type FCP.
490  */
491 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
492 {
493 	struct fc_frame_header *fh = fc_frame_header_get(fp);
494 
495 	switch (fh->fh_r_ctl) {
496 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
497 		ft_recv_cmd(sess, fp);
498 		break;
499 	case FC_RCTL_DD_SOL_DATA:	/* write data */
500 	case FC_RCTL_DD_UNSOL_CTL:
501 	case FC_RCTL_DD_SOL_CTL:
502 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
503 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
504 	default:
505 		pr_debug("%s: unhandled frame r_ctl %x\n",
506 		       __func__, fh->fh_r_ctl);
507 		fc_frame_free(fp);
508 		ft_sess_put(sess);	/* undo get from lookup */
509 		break;
510 	}
511 }
512 
513 /*
514  * Send new command to target.
515  */
516 static void ft_send_work(struct work_struct *work)
517 {
518 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
519 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
520 	struct fcp_cmnd *fcp;
521 	int data_dir = 0;
522 	int task_attr;
523 
524 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
525 	if (!fcp)
526 		goto err;
527 
528 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
529 		goto err;		/* not handling longer CDBs yet */
530 
531 	/*
532 	 * Check for FCP task management flags
533 	 */
534 	if (fcp->fc_tm_flags) {
535 		ft_send_tm(cmd);
536 		return;
537 	}
538 
539 	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
540 	case 0:
541 		data_dir = DMA_NONE;
542 		break;
543 	case FCP_CFL_RDDATA:
544 		data_dir = DMA_FROM_DEVICE;
545 		break;
546 	case FCP_CFL_WRDATA:
547 		data_dir = DMA_TO_DEVICE;
548 		break;
549 	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
550 		goto err;	/* TBD not supported by tcm_fc yet */
551 	}
552 	/*
553 	 * Locate the SAM Task Attr from fc_pri_ta
554 	 */
555 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
556 	case FCP_PTA_HEADQ:
557 		task_attr = TCM_HEAD_TAG;
558 		break;
559 	case FCP_PTA_ORDERED:
560 		task_attr = TCM_ORDERED_TAG;
561 		break;
562 	case FCP_PTA_ACA:
563 		task_attr = TCM_ACA_TAG;
564 		break;
565 	case FCP_PTA_SIMPLE: /* Fallthrough */
566 	default:
567 		task_attr = TCM_SIMPLE_TAG;
568 	}
569 
570 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
571 	/*
572 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
573 	 * directly from ft_check_stop_free callback in response path.
574 	 */
575 	if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
576 			      &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
577 			      ntohl(fcp->fc_dl), task_attr, data_dir, 0))
578 		goto err;
579 
580 	pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
581 	return;
582 
583 err:
584 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
585 }
586