xref: /openbmc/linux/drivers/target/tcm_fc/tfc_cmd.c (revision c0e297dc) 
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 #include <target/configfs_macros.h>
40 
41 #include "tcm_fc.h"
42 
43 /*
44  * Dump cmd state for debugging.
45  */
46 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
47 {
48 	struct fc_exch *ep;
49 	struct fc_seq *sp;
50 	struct se_cmd *se_cmd;
51 	struct scatterlist *sg;
52 	int count;
53 
54 	se_cmd = &cmd->se_cmd;
55 	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
56 		caller, cmd, cmd->sess, cmd->seq, se_cmd);
57 
58 	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
59 		caller, cmd, se_cmd->t_data_nents,
60 	       se_cmd->data_length, se_cmd->se_cmd_flags);
61 
62 	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
63 		pr_debug("%s: cmd %p sg %p page %p "
64 			"len 0x%x off 0x%x\n",
65 			caller, cmd, sg,
66 			sg_page(sg), sg->length, sg->offset);
67 
68 	sp = cmd->seq;
69 	if (sp) {
70 		ep = fc_seq_exch(sp);
71 		pr_debug("%s: cmd %p sid %x did %x "
72 			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
73 			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
74 			sp->id, ep->esb_stat);
75 	}
76 }
77 
78 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
79 {
80 	if (unlikely(ft_debug_logging))
81 		_ft_dump_cmd(cmd, caller);
82 }
83 
84 static void ft_free_cmd(struct ft_cmd *cmd)
85 {
86 	struct fc_frame *fp;
87 	struct fc_lport *lport;
88 	struct ft_sess *sess;
89 
90 	if (!cmd)
91 		return;
92 	sess = cmd->sess;
93 	fp = cmd->req_frame;
94 	lport = fr_dev(fp);
95 	if (fr_seq(fp))
96 		lport->tt.seq_release(fr_seq(fp));
97 	fc_frame_free(fp);
98 	percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
99 	ft_sess_put(sess);	/* undo get from lookup at recv */
100 }
101 
102 void ft_release_cmd(struct se_cmd *se_cmd)
103 {
104 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
105 
106 	ft_free_cmd(cmd);
107 }
108 
109 int ft_check_stop_free(struct se_cmd *se_cmd)
110 {
111 	transport_generic_free_cmd(se_cmd, 0);
112 	return 1;
113 }
114 
115 /*
116  * Send response.
117  */
118 int ft_queue_status(struct se_cmd *se_cmd)
119 {
120 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
121 	struct fc_frame *fp;
122 	struct fcp_resp_with_ext *fcp;
123 	struct fc_lport *lport;
124 	struct fc_exch *ep;
125 	size_t len;
126 	int rc;
127 
128 	if (cmd->aborted)
129 		return 0;
130 	ft_dump_cmd(cmd, __func__);
131 	ep = fc_seq_exch(cmd->seq);
132 	lport = ep->lp;
133 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
134 	fp = fc_frame_alloc(lport, len);
135 	if (!fp) {
136 		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
137 		return -ENOMEM;
138 	}
139 
140 	fcp = fc_frame_payload_get(fp, len);
141 	memset(fcp, 0, len);
142 	fcp->resp.fr_status = se_cmd->scsi_status;
143 
144 	len = se_cmd->scsi_sense_length;
145 	if (len) {
146 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
147 		fcp->ext.fr_sns_len = htonl(len);
148 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
149 	}
150 
151 	/*
152 	 * Test underflow and overflow with one mask.  Usually both are off.
153 	 * Bidirectional commands are not handled yet.
154 	 */
155 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
156 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
157 			fcp->resp.fr_flags |= FCP_RESID_OVER;
158 		else
159 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
160 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
161 	}
162 
163 	/*
164 	 * Send response.
165 	 */
166 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
167 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
168 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
169 
170 	rc = lport->tt.seq_send(lport, cmd->seq, fp);
171 	if (rc) {
172 		pr_info_ratelimited("%s: Failed to send response frame %p, "
173 				    "xid <0x%x>\n", __func__, fp, ep->xid);
174 		/*
175 		 * Generate a TASK_SET_FULL status to notify the initiator
176 		 * to reduce it's queue_depth after the se_cmd response has
177 		 * been re-queued by target-core.
178 		 */
179 		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
180 		return -ENOMEM;
181 	}
182 	lport->tt.exch_done(cmd->seq);
183 	return 0;
184 }
185 
186 int ft_write_pending_status(struct se_cmd *se_cmd)
187 {
188 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
189 
190 	return cmd->write_data_len != se_cmd->data_length;
191 }
192 
193 /*
194  * Send TX_RDY (transfer ready).
195  */
196 int ft_write_pending(struct se_cmd *se_cmd)
197 {
198 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
199 	struct fc_frame *fp;
200 	struct fcp_txrdy *txrdy;
201 	struct fc_lport *lport;
202 	struct fc_exch *ep;
203 	struct fc_frame_header *fh;
204 	u32 f_ctl;
205 
206 	ft_dump_cmd(cmd, __func__);
207 
208 	if (cmd->aborted)
209 		return 0;
210 	ep = fc_seq_exch(cmd->seq);
211 	lport = ep->lp;
212 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
213 	if (!fp)
214 		return -ENOMEM; /* Signal QUEUE_FULL */
215 
216 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
217 	memset(txrdy, 0, sizeof(*txrdy));
218 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
219 
220 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
221 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
222 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
223 
224 	fh = fc_frame_header_get(fp);
225 	f_ctl = ntoh24(fh->fh_f_ctl);
226 
227 	/* Only if it is 'Exchange Responder' */
228 	if (f_ctl & FC_FC_EX_CTX) {
229 		/* Target is 'exchange responder' and sending XFER_READY
230 		 * to 'exchange initiator (initiator)'
231 		 */
232 		if ((ep->xid <= lport->lro_xid) &&
233 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
234 			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
235 			    lport->tt.ddp_target(lport, ep->xid,
236 						 se_cmd->t_data_sg,
237 						 se_cmd->t_data_nents))
238 				cmd->was_ddp_setup = 1;
239 		}
240 	}
241 	lport->tt.seq_send(lport, cmd->seq, fp);
242 	return 0;
243 }
244 
245 int ft_get_cmd_state(struct se_cmd *se_cmd)
246 {
247 	return 0;
248 }
249 
250 /*
251  * FC sequence response handler for follow-on sequences (data) and aborts.
252  */
253 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
254 {
255 	struct ft_cmd *cmd = arg;
256 	struct fc_frame_header *fh;
257 
258 	if (unlikely(IS_ERR(fp))) {
259 		/* XXX need to find cmd if queued */
260 		cmd->seq = NULL;
261 		cmd->aborted = true;
262 		return;
263 	}
264 
265 	fh = fc_frame_header_get(fp);
266 
267 	switch (fh->fh_r_ctl) {
268 	case FC_RCTL_DD_SOL_DATA:	/* write data */
269 		ft_recv_write_data(cmd, fp);
270 		break;
271 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
272 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
273 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
274 	default:
275 		pr_debug("%s: unhandled frame r_ctl %x\n",
276 		       __func__, fh->fh_r_ctl);
277 		ft_invl_hw_context(cmd);
278 		fc_frame_free(fp);
279 		transport_generic_free_cmd(&cmd->se_cmd, 0);
280 		break;
281 	}
282 }
283 
284 /*
285  * Send a FCP response including SCSI status and optional FCP rsp_code.
286  * status is SAM_STAT_GOOD (zero) iff code is valid.
287  * This is used in error cases, such as allocation failures.
288  */
289 static void ft_send_resp_status(struct fc_lport *lport,
290 				const struct fc_frame *rx_fp,
291 				u32 status, enum fcp_resp_rsp_codes code)
292 {
293 	struct fc_frame *fp;
294 	struct fc_seq *sp;
295 	const struct fc_frame_header *fh;
296 	size_t len;
297 	struct fcp_resp_with_ext *fcp;
298 	struct fcp_resp_rsp_info *info;
299 
300 	fh = fc_frame_header_get(rx_fp);
301 	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
302 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
303 	len = sizeof(*fcp);
304 	if (status == SAM_STAT_GOOD)
305 		len += sizeof(*info);
306 	fp = fc_frame_alloc(lport, len);
307 	if (!fp)
308 		return;
309 	fcp = fc_frame_payload_get(fp, len);
310 	memset(fcp, 0, len);
311 	fcp->resp.fr_status = status;
312 	if (status == SAM_STAT_GOOD) {
313 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
314 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
315 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
316 		info->rsp_code = code;
317 	}
318 
319 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
320 	sp = fr_seq(fp);
321 	if (sp) {
322 		lport->tt.seq_send(lport, sp, fp);
323 		lport->tt.exch_done(sp);
324 	} else {
325 		lport->tt.frame_send(lport, fp);
326 	}
327 }
328 
329 /*
330  * Send error or task management response.
331  */
332 static void ft_send_resp_code(struct ft_cmd *cmd,
333 			      enum fcp_resp_rsp_codes code)
334 {
335 	ft_send_resp_status(cmd->sess->tport->lport,
336 			    cmd->req_frame, SAM_STAT_GOOD, code);
337 }
338 
339 
340 /*
341  * Send error or task management response.
342  * Always frees the cmd and associated state.
343  */
344 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
345 				      enum fcp_resp_rsp_codes code)
346 {
347 	ft_send_resp_code(cmd, code);
348 	ft_free_cmd(cmd);
349 }
350 
351 /*
352  * Handle Task Management Request.
353  */
354 static void ft_send_tm(struct ft_cmd *cmd)
355 {
356 	struct fcp_cmnd *fcp;
357 	int rc;
358 	u8 tm_func;
359 
360 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
361 
362 	switch (fcp->fc_tm_flags) {
363 	case FCP_TMF_LUN_RESET:
364 		tm_func = TMR_LUN_RESET;
365 		break;
366 	case FCP_TMF_TGT_RESET:
367 		tm_func = TMR_TARGET_WARM_RESET;
368 		break;
369 	case FCP_TMF_CLR_TASK_SET:
370 		tm_func = TMR_CLEAR_TASK_SET;
371 		break;
372 	case FCP_TMF_ABT_TASK_SET:
373 		tm_func = TMR_ABORT_TASK_SET;
374 		break;
375 	case FCP_TMF_CLR_ACA:
376 		tm_func = TMR_CLEAR_ACA;
377 		break;
378 	default:
379 		/*
380 		 * FCP4r01 indicates having a combination of
381 		 * tm_flags set is invalid.
382 		 */
383 		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
384 		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
385 		return;
386 	}
387 
388 	/* FIXME: Add referenced task tag for ABORT_TASK */
389 	rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
390 		&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
391 		cmd, tm_func, GFP_KERNEL, 0, 0);
392 	if (rc < 0)
393 		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
394 }
395 
396 /*
397  * Send status from completed task management request.
398  */
399 void ft_queue_tm_resp(struct se_cmd *se_cmd)
400 {
401 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
402 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
403 	enum fcp_resp_rsp_codes code;
404 
405 	if (cmd->aborted)
406 		return;
407 	switch (tmr->response) {
408 	case TMR_FUNCTION_COMPLETE:
409 		code = FCP_TMF_CMPL;
410 		break;
411 	case TMR_LUN_DOES_NOT_EXIST:
412 		code = FCP_TMF_INVALID_LUN;
413 		break;
414 	case TMR_FUNCTION_REJECTED:
415 		code = FCP_TMF_REJECTED;
416 		break;
417 	case TMR_TASK_DOES_NOT_EXIST:
418 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
419 	default:
420 		code = FCP_TMF_FAILED;
421 		break;
422 	}
423 	pr_debug("tmr fn %d resp %d fcp code %d\n",
424 		  tmr->function, tmr->response, code);
425 	ft_send_resp_code(cmd, code);
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;
444 
445 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
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->sess = sess;
454 	cmd->seq = lport->tt.seq_assign(lport, fp);
455 	if (!cmd->seq) {
456 		percpu_ida_free(&se_sess->sess_tag_pool, tag);
457 		goto busy;
458 	}
459 	cmd->req_frame = fp;		/* hold frame during cmd */
460 
461 	INIT_WORK(&cmd->work, ft_send_work);
462 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
463 	return;
464 
465 busy:
466 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
467 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
468 	fc_frame_free(fp);
469 	ft_sess_put(sess);		/* undo get from lookup */
470 }
471 
472 
473 /*
474  * Handle incoming FCP frame.
475  * Caller has verified that the frame is type FCP.
476  */
477 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
478 {
479 	struct fc_frame_header *fh = fc_frame_header_get(fp);
480 
481 	switch (fh->fh_r_ctl) {
482 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
483 		ft_recv_cmd(sess, fp);
484 		break;
485 	case FC_RCTL_DD_SOL_DATA:	/* write data */
486 	case FC_RCTL_DD_UNSOL_CTL:
487 	case FC_RCTL_DD_SOL_CTL:
488 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
489 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
490 	default:
491 		pr_debug("%s: unhandled frame r_ctl %x\n",
492 		       __func__, fh->fh_r_ctl);
493 		fc_frame_free(fp);
494 		ft_sess_put(sess);	/* undo get from lookup */
495 		break;
496 	}
497 }
498 
499 /*
500  * Send new command to target.
501  */
502 static void ft_send_work(struct work_struct *work)
503 {
504 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
505 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
506 	struct fcp_cmnd *fcp;
507 	int data_dir = 0;
508 	int task_attr;
509 
510 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
511 	if (!fcp)
512 		goto err;
513 
514 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
515 		goto err;		/* not handling longer CDBs yet */
516 
517 	/*
518 	 * Check for FCP task management flags
519 	 */
520 	if (fcp->fc_tm_flags) {
521 		ft_send_tm(cmd);
522 		return;
523 	}
524 
525 	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
526 	case 0:
527 		data_dir = DMA_NONE;
528 		break;
529 	case FCP_CFL_RDDATA:
530 		data_dir = DMA_FROM_DEVICE;
531 		break;
532 	case FCP_CFL_WRDATA:
533 		data_dir = DMA_TO_DEVICE;
534 		break;
535 	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
536 		goto err;	/* TBD not supported by tcm_fc yet */
537 	}
538 	/*
539 	 * Locate the SAM Task Attr from fc_pri_ta
540 	 */
541 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
542 	case FCP_PTA_HEADQ:
543 		task_attr = TCM_HEAD_TAG;
544 		break;
545 	case FCP_PTA_ORDERED:
546 		task_attr = TCM_ORDERED_TAG;
547 		break;
548 	case FCP_PTA_ACA:
549 		task_attr = TCM_ACA_TAG;
550 		break;
551 	case FCP_PTA_SIMPLE: /* Fallthrough */
552 	default:
553 		task_attr = TCM_SIMPLE_TAG;
554 	}
555 
556 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
557 	cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
558 	/*
559 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
560 	 * directly from ft_check_stop_free callback in response path.
561 	 */
562 	if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
563 			      &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
564 			      ntohl(fcp->fc_dl), task_attr, data_dir, 0))
565 		goto err;
566 
567 	pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
568 	return;
569 
570 err:
571 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
572 }
573