xref: /openbmc/linux/drivers/target/tcm_fc/tfc_cmd.c (revision 77d84ff8) 
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 se_session *se_sess;
94 
95 	if (!cmd)
96 		return;
97 	se_sess = cmd->sess->se_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(&se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
104 	ft_sess_put(cmd->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 
132 	if (cmd->aborted)
133 		return 0;
134 	ft_dump_cmd(cmd, __func__);
135 	ep = fc_seq_exch(cmd->seq);
136 	lport = ep->lp;
137 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
138 	fp = fc_frame_alloc(lport, len);
139 	if (!fp) {
140 		/* XXX shouldn't just drop it - requeue and retry? */
141 		return 0;
142 	}
143 	fcp = fc_frame_payload_get(fp, len);
144 	memset(fcp, 0, len);
145 	fcp->resp.fr_status = se_cmd->scsi_status;
146 
147 	len = se_cmd->scsi_sense_length;
148 	if (len) {
149 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
150 		fcp->ext.fr_sns_len = htonl(len);
151 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
152 	}
153 
154 	/*
155 	 * Test underflow and overflow with one mask.  Usually both are off.
156 	 * Bidirectional commands are not handled yet.
157 	 */
158 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
159 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
160 			fcp->resp.fr_flags |= FCP_RESID_OVER;
161 		else
162 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
163 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
164 	}
165 
166 	/*
167 	 * Send response.
168 	 */
169 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
170 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
171 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
172 
173 	lport->tt.seq_send(lport, cmd->seq, fp);
174 	lport->tt.exch_done(cmd->seq);
175 	return 0;
176 }
177 
178 int ft_write_pending_status(struct se_cmd *se_cmd)
179 {
180 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
181 
182 	return cmd->write_data_len != se_cmd->data_length;
183 }
184 
185 /*
186  * Send TX_RDY (transfer ready).
187  */
188 int ft_write_pending(struct se_cmd *se_cmd)
189 {
190 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
191 	struct fc_frame *fp;
192 	struct fcp_txrdy *txrdy;
193 	struct fc_lport *lport;
194 	struct fc_exch *ep;
195 	struct fc_frame_header *fh;
196 	u32 f_ctl;
197 
198 	ft_dump_cmd(cmd, __func__);
199 
200 	if (cmd->aborted)
201 		return 0;
202 	ep = fc_seq_exch(cmd->seq);
203 	lport = ep->lp;
204 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
205 	if (!fp)
206 		return -ENOMEM; /* Signal QUEUE_FULL */
207 
208 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
209 	memset(txrdy, 0, sizeof(*txrdy));
210 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
211 
212 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
213 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
214 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
215 
216 	fh = fc_frame_header_get(fp);
217 	f_ctl = ntoh24(fh->fh_f_ctl);
218 
219 	/* Only if it is 'Exchange Responder' */
220 	if (f_ctl & FC_FC_EX_CTX) {
221 		/* Target is 'exchange responder' and sending XFER_READY
222 		 * to 'exchange initiator (initiator)'
223 		 */
224 		if ((ep->xid <= lport->lro_xid) &&
225 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
226 			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
227 			    lport->tt.ddp_target(lport, ep->xid,
228 						 se_cmd->t_data_sg,
229 						 se_cmd->t_data_nents))
230 				cmd->was_ddp_setup = 1;
231 		}
232 	}
233 	lport->tt.seq_send(lport, cmd->seq, fp);
234 	return 0;
235 }
236 
237 u32 ft_get_task_tag(struct se_cmd *se_cmd)
238 {
239 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
240 
241 	if (cmd->aborted)
242 		return ~0;
243 	return fc_seq_exch(cmd->seq)->rxid;
244 }
245 
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  */
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 (unlikely(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  */
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 		lport->tt.seq_send(lport, sp, fp);
324 		lport->tt.exch_done(sp);
325 	} else {
326 		lport->tt.frame_send(lport, fp);
327 	}
328 }
329 
330 /*
331  * Send error or task management response.
332  */
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  */
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  */
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, 0);
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  */
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 
429 static void ft_send_work(struct work_struct *work);
430 
431 /*
432  * Handle incoming FCP command.
433  */
434 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
435 {
436 	struct ft_cmd *cmd;
437 	struct fc_lport *lport = sess->tport->lport;
438 	struct se_session *se_sess = sess->se_sess;
439 	int tag;
440 
441 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC);
442 	if (tag < 0)
443 		goto busy;
444 
445 	cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
446 	memset(cmd, 0, sizeof(struct ft_cmd));
447 
448 	cmd->se_cmd.map_tag = tag;
449 	cmd->sess = sess;
450 	cmd->seq = lport->tt.seq_assign(lport, fp);
451 	if (!cmd->seq) {
452 		percpu_ida_free(&se_sess->sess_tag_pool, tag);
453 		goto busy;
454 	}
455 	cmd->req_frame = fp;		/* hold frame during cmd */
456 
457 	INIT_WORK(&cmd->work, ft_send_work);
458 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
459 	return;
460 
461 busy:
462 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
463 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
464 	fc_frame_free(fp);
465 	ft_sess_put(sess);		/* undo get from lookup */
466 }
467 
468 
469 /*
470  * Handle incoming FCP frame.
471  * Caller has verified that the frame is type FCP.
472  */
473 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
474 {
475 	struct fc_frame_header *fh = fc_frame_header_get(fp);
476 
477 	switch (fh->fh_r_ctl) {
478 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
479 		ft_recv_cmd(sess, fp);
480 		break;
481 	case FC_RCTL_DD_SOL_DATA:	/* write data */
482 	case FC_RCTL_DD_UNSOL_CTL:
483 	case FC_RCTL_DD_SOL_CTL:
484 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
485 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
486 	default:
487 		pr_debug("%s: unhandled frame r_ctl %x\n",
488 		       __func__, fh->fh_r_ctl);
489 		fc_frame_free(fp);
490 		ft_sess_put(sess);	/* undo get from lookup */
491 		break;
492 	}
493 }
494 
495 /*
496  * Send new command to target.
497  */
498 static void ft_send_work(struct work_struct *work)
499 {
500 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
501 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
502 	struct fcp_cmnd *fcp;
503 	int data_dir = 0;
504 	int task_attr;
505 
506 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
507 	if (!fcp)
508 		goto err;
509 
510 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
511 		goto err;		/* not handling longer CDBs yet */
512 
513 	/*
514 	 * Check for FCP task management flags
515 	 */
516 	if (fcp->fc_tm_flags) {
517 		ft_send_tm(cmd);
518 		return;
519 	}
520 
521 	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
522 	case 0:
523 		data_dir = DMA_NONE;
524 		break;
525 	case FCP_CFL_RDDATA:
526 		data_dir = DMA_FROM_DEVICE;
527 		break;
528 	case FCP_CFL_WRDATA:
529 		data_dir = DMA_TO_DEVICE;
530 		break;
531 	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
532 		goto err;	/* TBD not supported by tcm_fc yet */
533 	}
534 	/*
535 	 * Locate the SAM Task Attr from fc_pri_ta
536 	 */
537 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
538 	case FCP_PTA_HEADQ:
539 		task_attr = MSG_HEAD_TAG;
540 		break;
541 	case FCP_PTA_ORDERED:
542 		task_attr = MSG_ORDERED_TAG;
543 		break;
544 	case FCP_PTA_ACA:
545 		task_attr = MSG_ACA_TAG;
546 		break;
547 	case FCP_PTA_SIMPLE: /* Fallthrough */
548 	default:
549 		task_attr = MSG_SIMPLE_TAG;
550 	}
551 
552 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
553 	/*
554 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
555 	 * directly from ft_check_stop_free callback in response path.
556 	 */
557 	if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
558 			      &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
559 			      ntohl(fcp->fc_dl), task_attr, data_dir, 0))
560 		goto err;
561 
562 	pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
563 	return;
564 
565 err:
566 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
567 }
568