xref: /linux/drivers/target/tcm_fc/tfc_cmd.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571) 
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 <generated/utsrelease.h>
23 #include <linux/utsname.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/kthread.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/configfs.h>
30 #include <linux/ctype.h>
31 #include <linux/hash.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 
94 	if (!cmd)
95 		return;
96 	fp = cmd->req_frame;
97 	lport = fr_dev(fp);
98 	if (fr_seq(fp))
99 		lport->tt.seq_release(fr_seq(fp));
100 	fc_frame_free(fp);
101 	ft_sess_put(cmd->sess);	/* undo get from lookup at recv */
102 	kfree(cmd);
103 }
104 
105 void ft_release_cmd(struct se_cmd *se_cmd)
106 {
107 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
108 
109 	ft_free_cmd(cmd);
110 }
111 
112 int ft_check_stop_free(struct se_cmd *se_cmd)
113 {
114 	transport_generic_free_cmd(se_cmd, 0);
115 	return 1;
116 }
117 
118 /*
119  * Send response.
120  */
121 int ft_queue_status(struct se_cmd *se_cmd)
122 {
123 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
124 	struct fc_frame *fp;
125 	struct fcp_resp_with_ext *fcp;
126 	struct fc_lport *lport;
127 	struct fc_exch *ep;
128 	size_t len;
129 
130 	if (cmd->aborted)
131 		return 0;
132 	ft_dump_cmd(cmd, __func__);
133 	ep = fc_seq_exch(cmd->seq);
134 	lport = ep->lp;
135 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
136 	fp = fc_frame_alloc(lport, len);
137 	if (!fp) {
138 		/* XXX shouldn't just drop it - requeue and retry? */
139 		return 0;
140 	}
141 	fcp = fc_frame_payload_get(fp, len);
142 	memset(fcp, 0, len);
143 	fcp->resp.fr_status = se_cmd->scsi_status;
144 
145 	len = se_cmd->scsi_sense_length;
146 	if (len) {
147 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
148 		fcp->ext.fr_sns_len = htonl(len);
149 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
150 	}
151 
152 	/*
153 	 * Test underflow and overflow with one mask.  Usually both are off.
154 	 * Bidirectional commands are not handled yet.
155 	 */
156 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
157 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
158 			fcp->resp.fr_flags |= FCP_RESID_OVER;
159 		else
160 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
161 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
162 	}
163 
164 	/*
165 	 * Send response.
166 	 */
167 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
168 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
169 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
170 
171 	lport->tt.seq_send(lport, cmd->seq, fp);
172 	lport->tt.exch_done(cmd->seq);
173 	return 0;
174 }
175 
176 int ft_write_pending_status(struct se_cmd *se_cmd)
177 {
178 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
179 
180 	return cmd->write_data_len != se_cmd->data_length;
181 }
182 
183 /*
184  * Send TX_RDY (transfer ready).
185  */
186 int ft_write_pending(struct se_cmd *se_cmd)
187 {
188 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
189 	struct fc_frame *fp;
190 	struct fcp_txrdy *txrdy;
191 	struct fc_lport *lport;
192 	struct fc_exch *ep;
193 	struct fc_frame_header *fh;
194 	u32 f_ctl;
195 
196 	ft_dump_cmd(cmd, __func__);
197 
198 	if (cmd->aborted)
199 		return 0;
200 	ep = fc_seq_exch(cmd->seq);
201 	lport = ep->lp;
202 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
203 	if (!fp)
204 		return -ENOMEM; /* Signal QUEUE_FULL */
205 
206 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
207 	memset(txrdy, 0, sizeof(*txrdy));
208 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
209 
210 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
211 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
212 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
213 
214 	fh = fc_frame_header_get(fp);
215 	f_ctl = ntoh24(fh->fh_f_ctl);
216 
217 	/* Only if it is 'Exchange Responder' */
218 	if (f_ctl & FC_FC_EX_CTX) {
219 		/* Target is 'exchange responder' and sending XFER_READY
220 		 * to 'exchange initiator (initiator)'
221 		 */
222 		if ((ep->xid <= lport->lro_xid) &&
223 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
224 			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
225 			    lport->tt.ddp_target(lport, ep->xid,
226 						 se_cmd->t_data_sg,
227 						 se_cmd->t_data_nents))
228 				cmd->was_ddp_setup = 1;
229 		}
230 	}
231 	lport->tt.seq_send(lport, cmd->seq, fp);
232 	return 0;
233 }
234 
235 u32 ft_get_task_tag(struct se_cmd *se_cmd)
236 {
237 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
238 
239 	if (cmd->aborted)
240 		return ~0;
241 	return fc_seq_exch(cmd->seq)->rxid;
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 (unlikely(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 int 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 0;
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_STILL_ALLEGIANT:
418 	case TMR_TASK_FAILOVER_NOT_SUPPORTED:
419 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
420 	case TMR_FUNCTION_AUTHORIZATION_FAILED:
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 	return 0;
429 }
430 
431 static void ft_send_work(struct work_struct *work);
432 
433 /*
434  * Handle incoming FCP command.
435  */
436 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
437 {
438 	struct ft_cmd *cmd;
439 	struct fc_lport *lport = sess->tport->lport;
440 
441 	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
442 	if (!cmd)
443 		goto busy;
444 	cmd->sess = sess;
445 	cmd->seq = lport->tt.seq_assign(lport, fp);
446 	if (!cmd->seq) {
447 		kfree(cmd);
448 		goto busy;
449 	}
450 	cmd->req_frame = fp;		/* hold frame during cmd */
451 
452 	INIT_WORK(&cmd->work, ft_send_work);
453 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
454 	return;
455 
456 busy:
457 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
458 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
459 	fc_frame_free(fp);
460 	ft_sess_put(sess);		/* undo get from lookup */
461 }
462 
463 
464 /*
465  * Handle incoming FCP frame.
466  * Caller has verified that the frame is type FCP.
467  */
468 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
469 {
470 	struct fc_frame_header *fh = fc_frame_header_get(fp);
471 
472 	switch (fh->fh_r_ctl) {
473 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
474 		ft_recv_cmd(sess, fp);
475 		break;
476 	case FC_RCTL_DD_SOL_DATA:	/* write data */
477 	case FC_RCTL_DD_UNSOL_CTL:
478 	case FC_RCTL_DD_SOL_CTL:
479 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
480 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
481 	default:
482 		pr_debug("%s: unhandled frame r_ctl %x\n",
483 		       __func__, fh->fh_r_ctl);
484 		fc_frame_free(fp);
485 		ft_sess_put(sess);	/* undo get from lookup */
486 		break;
487 	}
488 }
489 
490 /*
491  * Send new command to target.
492  */
493 static void ft_send_work(struct work_struct *work)
494 {
495 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
496 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
497 	struct fcp_cmnd *fcp;
498 	int data_dir = 0;
499 	int task_attr;
500 
501 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
502 	if (!fcp)
503 		goto err;
504 
505 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
506 		goto err;		/* not handling longer CDBs yet */
507 
508 	/*
509 	 * Check for FCP task management flags
510 	 */
511 	if (fcp->fc_tm_flags) {
512 		ft_send_tm(cmd);
513 		return;
514 	}
515 
516 	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
517 	case 0:
518 		data_dir = DMA_NONE;
519 		break;
520 	case FCP_CFL_RDDATA:
521 		data_dir = DMA_FROM_DEVICE;
522 		break;
523 	case FCP_CFL_WRDATA:
524 		data_dir = DMA_TO_DEVICE;
525 		break;
526 	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
527 		goto err;	/* TBD not supported by tcm_fc yet */
528 	}
529 	/*
530 	 * Locate the SAM Task Attr from fc_pri_ta
531 	 */
532 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
533 	case FCP_PTA_HEADQ:
534 		task_attr = MSG_HEAD_TAG;
535 		break;
536 	case FCP_PTA_ORDERED:
537 		task_attr = MSG_ORDERED_TAG;
538 		break;
539 	case FCP_PTA_ACA:
540 		task_attr = MSG_ACA_TAG;
541 		break;
542 	case FCP_PTA_SIMPLE: /* Fallthrough */
543 	default:
544 		task_attr = MSG_SIMPLE_TAG;
545 	}
546 
547 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
548 	/*
549 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
550 	 * directly from ft_check_stop_free callback in response path.
551 	 */
552 	if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
553 			      &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
554 			      ntohl(fcp->fc_dl), task_attr, data_dir, 0))
555 		goto err;
556 
557 	pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
558 	return;
559 
560 err:
561 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
562 }
563