xref: /openbmc/linux/drivers/target/tcm_fc/tfc_cmd.c (revision e23feb16) 
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.h>
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi_device.h>
35 #include <scsi/scsi_cmnd.h>
36 #include <scsi/scsi_tcq.h>
37 #include <scsi/libfc.h>
38 #include <scsi/fc_encode.h>
39 
40 #include <target/target_core_base.h>
41 #include <target/target_core_fabric.h>
42 #include <target/target_core_configfs.h>
43 #include <target/configfs_macros.h>
44 
45 #include "tcm_fc.h"
46 
47 /*
48  * Dump cmd state for debugging.
49  */
50 static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
51 {
52 	struct fc_exch *ep;
53 	struct fc_seq *sp;
54 	struct se_cmd *se_cmd;
55 	struct scatterlist *sg;
56 	int count;
57 
58 	se_cmd = &cmd->se_cmd;
59 	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
60 		caller, cmd, cmd->sess, cmd->seq, se_cmd);
61 
62 	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
63 		caller, cmd, se_cmd->t_data_nents,
64 	       se_cmd->data_length, se_cmd->se_cmd_flags);
65 
66 	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
67 		pr_debug("%s: cmd %p sg %p page %p "
68 			"len 0x%x off 0x%x\n",
69 			caller, cmd, sg,
70 			sg_page(sg), sg->length, sg->offset);
71 
72 	sp = cmd->seq;
73 	if (sp) {
74 		ep = fc_seq_exch(sp);
75 		pr_debug("%s: cmd %p sid %x did %x "
76 			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
77 			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
78 			sp->id, ep->esb_stat);
79 	}
80 }
81 
82 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
83 {
84 	if (unlikely(ft_debug_logging))
85 		_ft_dump_cmd(cmd, caller);
86 }
87 
88 static void ft_free_cmd(struct ft_cmd *cmd)
89 {
90 	struct fc_frame *fp;
91 	struct fc_lport *lport;
92 
93 	if (!cmd)
94 		return;
95 	fp = cmd->req_frame;
96 	lport = fr_dev(fp);
97 	if (fr_seq(fp))
98 		lport->tt.seq_release(fr_seq(fp));
99 	fc_frame_free(fp);
100 	ft_sess_put(cmd->sess);	/* undo get from lookup at recv */
101 	kfree(cmd);
102 }
103 
104 void ft_release_cmd(struct se_cmd *se_cmd)
105 {
106 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
107 
108 	ft_free_cmd(cmd);
109 }
110 
111 int ft_check_stop_free(struct se_cmd *se_cmd)
112 {
113 	transport_generic_free_cmd(se_cmd, 0);
114 	return 1;
115 }
116 
117 /*
118  * Send response.
119  */
120 int ft_queue_status(struct se_cmd *se_cmd)
121 {
122 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
123 	struct fc_frame *fp;
124 	struct fcp_resp_with_ext *fcp;
125 	struct fc_lport *lport;
126 	struct fc_exch *ep;
127 	size_t len;
128 
129 	if (cmd->aborted)
130 		return 0;
131 	ft_dump_cmd(cmd, __func__);
132 	ep = fc_seq_exch(cmd->seq);
133 	lport = ep->lp;
134 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
135 	fp = fc_frame_alloc(lport, len);
136 	if (!fp) {
137 		/* XXX shouldn't just drop it - requeue and retry? */
138 		return 0;
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 	lport->tt.seq_send(lport, cmd->seq, fp);
171 	lport->tt.exch_done(cmd->seq);
172 	return 0;
173 }
174 
175 int ft_write_pending_status(struct se_cmd *se_cmd)
176 {
177 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
178 
179 	return cmd->write_data_len != se_cmd->data_length;
180 }
181 
182 /*
183  * Send TX_RDY (transfer ready).
184  */
185 int ft_write_pending(struct se_cmd *se_cmd)
186 {
187 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
188 	struct fc_frame *fp;
189 	struct fcp_txrdy *txrdy;
190 	struct fc_lport *lport;
191 	struct fc_exch *ep;
192 	struct fc_frame_header *fh;
193 	u32 f_ctl;
194 
195 	ft_dump_cmd(cmd, __func__);
196 
197 	if (cmd->aborted)
198 		return 0;
199 	ep = fc_seq_exch(cmd->seq);
200 	lport = ep->lp;
201 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
202 	if (!fp)
203 		return -ENOMEM; /* Signal QUEUE_FULL */
204 
205 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
206 	memset(txrdy, 0, sizeof(*txrdy));
207 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
208 
209 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
210 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
211 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
212 
213 	fh = fc_frame_header_get(fp);
214 	f_ctl = ntoh24(fh->fh_f_ctl);
215 
216 	/* Only if it is 'Exchange Responder' */
217 	if (f_ctl & FC_FC_EX_CTX) {
218 		/* Target is 'exchange responder' and sending XFER_READY
219 		 * to 'exchange initiator (initiator)'
220 		 */
221 		if ((ep->xid <= lport->lro_xid) &&
222 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
223 			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
224 			    lport->tt.ddp_target(lport, ep->xid,
225 						 se_cmd->t_data_sg,
226 						 se_cmd->t_data_nents))
227 				cmd->was_ddp_setup = 1;
228 		}
229 	}
230 	lport->tt.seq_send(lport, cmd->seq, fp);
231 	return 0;
232 }
233 
234 u32 ft_get_task_tag(struct se_cmd *se_cmd)
235 {
236 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
237 
238 	if (cmd->aborted)
239 		return ~0;
240 	return fc_seq_exch(cmd->seq)->rxid;
241 }
242 
243 int ft_get_cmd_state(struct se_cmd *se_cmd)
244 {
245 	return 0;
246 }
247 
248 /*
249  * FC sequence response handler for follow-on sequences (data) and aborts.
250  */
251 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
252 {
253 	struct ft_cmd *cmd = arg;
254 	struct fc_frame_header *fh;
255 
256 	if (unlikely(IS_ERR(fp))) {
257 		/* XXX need to find cmd if queued */
258 		cmd->seq = NULL;
259 		cmd->aborted = true;
260 		return;
261 	}
262 
263 	fh = fc_frame_header_get(fp);
264 
265 	switch (fh->fh_r_ctl) {
266 	case FC_RCTL_DD_SOL_DATA:	/* write data */
267 		ft_recv_write_data(cmd, fp);
268 		break;
269 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
270 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
271 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
272 	default:
273 		pr_debug("%s: unhandled frame r_ctl %x\n",
274 		       __func__, fh->fh_r_ctl);
275 		ft_invl_hw_context(cmd);
276 		fc_frame_free(fp);
277 		transport_generic_free_cmd(&cmd->se_cmd, 0);
278 		break;
279 	}
280 }
281 
282 /*
283  * Send a FCP response including SCSI status and optional FCP rsp_code.
284  * status is SAM_STAT_GOOD (zero) iff code is valid.
285  * This is used in error cases, such as allocation failures.
286  */
287 static void ft_send_resp_status(struct fc_lport *lport,
288 				const struct fc_frame *rx_fp,
289 				u32 status, enum fcp_resp_rsp_codes code)
290 {
291 	struct fc_frame *fp;
292 	struct fc_seq *sp;
293 	const struct fc_frame_header *fh;
294 	size_t len;
295 	struct fcp_resp_with_ext *fcp;
296 	struct fcp_resp_rsp_info *info;
297 
298 	fh = fc_frame_header_get(rx_fp);
299 	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
300 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
301 	len = sizeof(*fcp);
302 	if (status == SAM_STAT_GOOD)
303 		len += sizeof(*info);
304 	fp = fc_frame_alloc(lport, len);
305 	if (!fp)
306 		return;
307 	fcp = fc_frame_payload_get(fp, len);
308 	memset(fcp, 0, len);
309 	fcp->resp.fr_status = status;
310 	if (status == SAM_STAT_GOOD) {
311 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
312 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
313 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
314 		info->rsp_code = code;
315 	}
316 
317 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
318 	sp = fr_seq(fp);
319 	if (sp) {
320 		lport->tt.seq_send(lport, sp, fp);
321 		lport->tt.exch_done(sp);
322 	} else {
323 		lport->tt.frame_send(lport, fp);
324 	}
325 }
326 
327 /*
328  * Send error or task management response.
329  */
330 static void ft_send_resp_code(struct ft_cmd *cmd,
331 			      enum fcp_resp_rsp_codes code)
332 {
333 	ft_send_resp_status(cmd->sess->tport->lport,
334 			    cmd->req_frame, SAM_STAT_GOOD, code);
335 }
336 
337 
338 /*
339  * Send error or task management response.
340  * Always frees the cmd and associated state.
341  */
342 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
343 				      enum fcp_resp_rsp_codes code)
344 {
345 	ft_send_resp_code(cmd, code);
346 	ft_free_cmd(cmd);
347 }
348 
349 /*
350  * Handle Task Management Request.
351  */
352 static void ft_send_tm(struct ft_cmd *cmd)
353 {
354 	struct fcp_cmnd *fcp;
355 	int rc;
356 	u8 tm_func;
357 
358 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
359 
360 	switch (fcp->fc_tm_flags) {
361 	case FCP_TMF_LUN_RESET:
362 		tm_func = TMR_LUN_RESET;
363 		break;
364 	case FCP_TMF_TGT_RESET:
365 		tm_func = TMR_TARGET_WARM_RESET;
366 		break;
367 	case FCP_TMF_CLR_TASK_SET:
368 		tm_func = TMR_CLEAR_TASK_SET;
369 		break;
370 	case FCP_TMF_ABT_TASK_SET:
371 		tm_func = TMR_ABORT_TASK_SET;
372 		break;
373 	case FCP_TMF_CLR_ACA:
374 		tm_func = TMR_CLEAR_ACA;
375 		break;
376 	default:
377 		/*
378 		 * FCP4r01 indicates having a combination of
379 		 * tm_flags set is invalid.
380 		 */
381 		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
382 		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
383 		return;
384 	}
385 
386 	/* FIXME: Add referenced task tag for ABORT_TASK */
387 	rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
388 		&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
389 		cmd, tm_func, GFP_KERNEL, 0, 0);
390 	if (rc < 0)
391 		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
392 }
393 
394 /*
395  * Send status from completed task management request.
396  */
397 void ft_queue_tm_resp(struct se_cmd *se_cmd)
398 {
399 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
400 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
401 	enum fcp_resp_rsp_codes code;
402 
403 	if (cmd->aborted)
404 		return;
405 	switch (tmr->response) {
406 	case TMR_FUNCTION_COMPLETE:
407 		code = FCP_TMF_CMPL;
408 		break;
409 	case TMR_LUN_DOES_NOT_EXIST:
410 		code = FCP_TMF_INVALID_LUN;
411 		break;
412 	case TMR_FUNCTION_REJECTED:
413 		code = FCP_TMF_REJECTED;
414 		break;
415 	case TMR_TASK_DOES_NOT_EXIST:
416 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
417 	default:
418 		code = FCP_TMF_FAILED;
419 		break;
420 	}
421 	pr_debug("tmr fn %d resp %d fcp code %d\n",
422 		  tmr->function, tmr->response, code);
423 	ft_send_resp_code(cmd, code);
424 }
425 
426 static void ft_send_work(struct work_struct *work);
427 
428 /*
429  * Handle incoming FCP command.
430  */
431 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
432 {
433 	struct ft_cmd *cmd;
434 	struct fc_lport *lport = sess->tport->lport;
435 
436 	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
437 	if (!cmd)
438 		goto busy;
439 	cmd->sess = sess;
440 	cmd->seq = lport->tt.seq_assign(lport, fp);
441 	if (!cmd->seq) {
442 		kfree(cmd);
443 		goto busy;
444 	}
445 	cmd->req_frame = fp;		/* hold frame during cmd */
446 
447 	INIT_WORK(&cmd->work, ft_send_work);
448 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
449 	return;
450 
451 busy:
452 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
453 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
454 	fc_frame_free(fp);
455 	ft_sess_put(sess);		/* undo get from lookup */
456 }
457 
458 
459 /*
460  * Handle incoming FCP frame.
461  * Caller has verified that the frame is type FCP.
462  */
463 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
464 {
465 	struct fc_frame_header *fh = fc_frame_header_get(fp);
466 
467 	switch (fh->fh_r_ctl) {
468 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
469 		ft_recv_cmd(sess, fp);
470 		break;
471 	case FC_RCTL_DD_SOL_DATA:	/* write data */
472 	case FC_RCTL_DD_UNSOL_CTL:
473 	case FC_RCTL_DD_SOL_CTL:
474 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
475 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
476 	default:
477 		pr_debug("%s: unhandled frame r_ctl %x\n",
478 		       __func__, fh->fh_r_ctl);
479 		fc_frame_free(fp);
480 		ft_sess_put(sess);	/* undo get from lookup */
481 		break;
482 	}
483 }
484 
485 /*
486  * Send new command to target.
487  */
488 static void ft_send_work(struct work_struct *work)
489 {
490 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
491 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
492 	struct fcp_cmnd *fcp;
493 	int data_dir = 0;
494 	int task_attr;
495 
496 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
497 	if (!fcp)
498 		goto err;
499 
500 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
501 		goto err;		/* not handling longer CDBs yet */
502 
503 	/*
504 	 * Check for FCP task management flags
505 	 */
506 	if (fcp->fc_tm_flags) {
507 		ft_send_tm(cmd);
508 		return;
509 	}
510 
511 	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
512 	case 0:
513 		data_dir = DMA_NONE;
514 		break;
515 	case FCP_CFL_RDDATA:
516 		data_dir = DMA_FROM_DEVICE;
517 		break;
518 	case FCP_CFL_WRDATA:
519 		data_dir = DMA_TO_DEVICE;
520 		break;
521 	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
522 		goto err;	/* TBD not supported by tcm_fc yet */
523 	}
524 	/*
525 	 * Locate the SAM Task Attr from fc_pri_ta
526 	 */
527 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
528 	case FCP_PTA_HEADQ:
529 		task_attr = MSG_HEAD_TAG;
530 		break;
531 	case FCP_PTA_ORDERED:
532 		task_attr = MSG_ORDERED_TAG;
533 		break;
534 	case FCP_PTA_ACA:
535 		task_attr = MSG_ACA_TAG;
536 		break;
537 	case FCP_PTA_SIMPLE: /* Fallthrough */
538 	default:
539 		task_attr = MSG_SIMPLE_TAG;
540 	}
541 
542 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
543 	/*
544 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
545 	 * directly from ft_check_stop_free callback in response path.
546 	 */
547 	if (target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
548 			      &cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
549 			      ntohl(fcp->fc_dl), task_attr, data_dir, 0))
550 		goto err;
551 
552 	pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
553 	return;
554 
555 err:
556 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
557 }
558