1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2010 Cisco Systems, Inc.
4 */
5
6/* XXX TBD some includes may be extraneous */
7
8#include <linux/module.h>
9#include <linux/moduleparam.h>
10#include <linux/utsname.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13#include <linux/kthread.h>
14#include <linux/types.h>
15#include <linux/string.h>
16#include <linux/configfs.h>
17#include <linux/ctype.h>
18#include <linux/hash.h>
19#include <asm/unaligned.h>
20#include <scsi/scsi_tcq.h>
21#include <scsi/libfc.h>
22
23#include <target/target_core_base.h>
24#include <target/target_core_fabric.h>
25
26#include "tcm_fc.h"
27
28/*
29 * Dump cmd state for debugging.
30 */
31static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
32{
33 struct fc_exch *ep;
34 struct fc_seq *sp;
35 struct se_cmd *se_cmd;
36 struct scatterlist *sg;
37 int count;
38
39 se_cmd = &cmd->se_cmd;
40 pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
41 caller, cmd, cmd->sess, cmd->seq, se_cmd);
42
43 pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
44 caller, cmd, se_cmd->t_data_nents,
45 se_cmd->data_length, se_cmd->se_cmd_flags);
46
47 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
48 pr_debug("%s: cmd %p sg %p page %p "
49 "len 0x%x off 0x%x\n",
50 caller, cmd, sg,
51 sg_page(sg), sg->length, sg->offset);
52
53 sp = cmd->seq;
54 if (sp) {
55 ep = fc_seq_exch(sp);
56 pr_debug("%s: cmd %p sid %x did %x "
57 "ox_id %x rx_id %x seq_id %x e_stat %x\n",
58 caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
59 sp->id, ep->esb_stat);
60 }
61}
62
63void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
64{
65 if (unlikely(ft_debug_logging))
66 _ft_dump_cmd(cmd, caller);
67}
68
69static void ft_free_cmd(struct ft_cmd *cmd)
70{
71 struct fc_frame *fp;
72 struct ft_sess *sess;
73
74 if (!cmd)
75 return;
76 sess = cmd->sess;
77 fp = cmd->req_frame;
78 if (fr_seq(fp))
79 fc_seq_release(fr_seq(fp));
80 fc_frame_free(fp);
81 target_free_tag(sess: sess->se_sess, cmd: &cmd->se_cmd);
82 ft_sess_put(sess); /* undo get from lookup at recv */
83}
84
85void ft_release_cmd(struct se_cmd *se_cmd)
86{
87 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
88
89 ft_free_cmd(cmd);
90}
91
92int ft_check_stop_free(struct se_cmd *se_cmd)
93{
94 return transport_generic_free_cmd(se_cmd, 0);
95}
96
97/*
98 * Send response.
99 */
100int ft_queue_status(struct se_cmd *se_cmd)
101{
102 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
103 struct fc_frame *fp;
104 struct fcp_resp_with_ext *fcp;
105 struct fc_lport *lport;
106 struct fc_exch *ep;
107 size_t len;
108 int rc;
109
110 if (cmd->aborted)
111 return 0;
112 ft_dump_cmd(cmd, caller: __func__);
113 ep = fc_seq_exch(cmd->seq);
114 lport = ep->lp;
115 len = sizeof(*fcp) + se_cmd->scsi_sense_length;
116 fp = fc_frame_alloc(dev: lport, len);
117 if (!fp) {
118 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
119 return -ENOMEM;
120 }
121
122 fcp = fc_frame_payload_get(fp, len);
123 memset(fcp, 0, len);
124 fcp->resp.fr_status = se_cmd->scsi_status;
125
126 len = se_cmd->scsi_sense_length;
127 if (len) {
128 fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
129 fcp->ext.fr_sns_len = htonl(len);
130 memcpy((fcp + 1), se_cmd->sense_buffer, len);
131 }
132
133 /*
134 * Test underflow and overflow with one mask. Usually both are off.
135 * Bidirectional commands are not handled yet.
136 */
137 if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
138 if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
139 fcp->resp.fr_flags |= FCP_RESID_OVER;
140 else
141 fcp->resp.fr_flags |= FCP_RESID_UNDER;
142 fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
143 }
144
145 /*
146 * Send response.
147 */
148 cmd->seq = fc_seq_start_next(sp: cmd->seq);
149 fc_fill_fc_hdr(fp, r_ctl: FC_RCTL_DD_CMD_STATUS, did: ep->did, sid: ep->sid, type: FC_TYPE_FCP,
150 FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, parm_offset: 0);
151
152 rc = fc_seq_send(lport, sp: cmd->seq, fp);
153 if (rc) {
154 pr_info_ratelimited("%s: Failed to send response frame %p, "
155 "xid <0x%x>\n", __func__, fp, ep->xid);
156 /*
157 * Generate a TASK_SET_FULL status to notify the initiator
158 * to reduce it's queue_depth after the se_cmd response has
159 * been re-queued by target-core.
160 */
161 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
162 return -ENOMEM;
163 }
164 fc_exch_done(sp: cmd->seq);
165 /*
166 * Drop the extra ACK_KREF reference taken by target_submit_cmd()
167 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
168 * final se_cmd->cmd_kref put.
169 */
170 target_put_sess_cmd(&cmd->se_cmd);
171 return 0;
172}
173
174/*
175 * Send TX_RDY (transfer ready).
176 */
177int ft_write_pending(struct se_cmd *se_cmd)
178{
179 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
180 struct fc_frame *fp;
181 struct fcp_txrdy *txrdy;
182 struct fc_lport *lport;
183 struct fc_exch *ep;
184 struct fc_frame_header *fh;
185 u32 f_ctl;
186
187 ft_dump_cmd(cmd, caller: __func__);
188
189 if (cmd->aborted)
190 return 0;
191 ep = fc_seq_exch(cmd->seq);
192 lport = ep->lp;
193 fp = fc_frame_alloc(dev: lport, len: sizeof(*txrdy));
194 if (!fp)
195 return -ENOMEM; /* Signal QUEUE_FULL */
196
197 txrdy = fc_frame_payload_get(fp, len: sizeof(*txrdy));
198 memset(txrdy, 0, sizeof(*txrdy));
199 txrdy->ft_burst_len = htonl(se_cmd->data_length);
200
201 cmd->seq = fc_seq_start_next(sp: cmd->seq);
202 fc_fill_fc_hdr(fp, r_ctl: FC_RCTL_DD_DATA_DESC, did: ep->did, sid: ep->sid, type: FC_TYPE_FCP,
203 FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, parm_offset: 0);
204
205 fh = fc_frame_header_get(fp);
206 f_ctl = ntoh24(p: fh->fh_f_ctl);
207
208 /* Only if it is 'Exchange Responder' */
209 if (f_ctl & FC_FC_EX_CTX) {
210 /* Target is 'exchange responder' and sending XFER_READY
211 * to 'exchange initiator (initiator)'
212 */
213 if ((ep->xid <= lport->lro_xid) &&
214 (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
215 if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
216 lport->tt.ddp_target(lport, ep->xid,
217 se_cmd->t_data_sg,
218 se_cmd->t_data_nents))
219 cmd->was_ddp_setup = 1;
220 }
221 }
222 fc_seq_send(lport, sp: cmd->seq, fp);
223 return 0;
224}
225
226/*
227 * FC sequence response handler for follow-on sequences (data) and aborts.
228 */
229static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
230{
231 struct ft_cmd *cmd = arg;
232 struct fc_frame_header *fh;
233
234 if (IS_ERR(ptr: fp)) {
235 /* XXX need to find cmd if queued */
236 cmd->seq = NULL;
237 cmd->aborted = true;
238 return;
239 }
240
241 fh = fc_frame_header_get(fp);
242
243 switch (fh->fh_r_ctl) {
244 case FC_RCTL_DD_SOL_DATA: /* write data */
245 ft_recv_write_data(cmd, fp);
246 break;
247 case FC_RCTL_DD_UNSOL_CTL: /* command */
248 case FC_RCTL_DD_SOL_CTL: /* transfer ready */
249 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
250 default:
251 pr_debug("%s: unhandled frame r_ctl %x\n",
252 __func__, fh->fh_r_ctl);
253 ft_invl_hw_context(cmd);
254 fc_frame_free(fp);
255 transport_generic_free_cmd(&cmd->se_cmd, 0);
256 break;
257 }
258}
259
260/*
261 * Send a FCP response including SCSI status and optional FCP rsp_code.
262 * status is SAM_STAT_GOOD (zero) iff code is valid.
263 * This is used in error cases, such as allocation failures.
264 */
265static void ft_send_resp_status(struct fc_lport *lport,
266 const struct fc_frame *rx_fp,
267 u32 status, enum fcp_resp_rsp_codes code)
268{
269 struct fc_frame *fp;
270 struct fc_seq *sp;
271 const struct fc_frame_header *fh;
272 size_t len;
273 struct fcp_resp_with_ext *fcp;
274 struct fcp_resp_rsp_info *info;
275
276 fh = fc_frame_header_get(fp: rx_fp);
277 pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
278 ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
279 len = sizeof(*fcp);
280 if (status == SAM_STAT_GOOD)
281 len += sizeof(*info);
282 fp = fc_frame_alloc(dev: lport, len);
283 if (!fp)
284 return;
285 fcp = fc_frame_payload_get(fp, len);
286 memset(fcp, 0, len);
287 fcp->resp.fr_status = status;
288 if (status == SAM_STAT_GOOD) {
289 fcp->ext.fr_rsp_len = htonl(sizeof(*info));
290 fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
291 info = (struct fcp_resp_rsp_info *)(fcp + 1);
292 info->rsp_code = code;
293 }
294
295 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, parm_offset: 0);
296 sp = fr_seq(fp);
297 if (sp) {
298 fc_seq_send(lport, sp, fp);
299 fc_exch_done(sp);
300 } else {
301 lport->tt.frame_send(lport, fp);
302 }
303}
304
305/*
306 * Send error or task management response.
307 */
308static void ft_send_resp_code(struct ft_cmd *cmd,
309 enum fcp_resp_rsp_codes code)
310{
311 ft_send_resp_status(lport: cmd->sess->tport->lport,
312 rx_fp: cmd->req_frame, status: SAM_STAT_GOOD, code);
313}
314
315
316/*
317 * Send error or task management response.
318 * Always frees the cmd and associated state.
319 */
320static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
321 enum fcp_resp_rsp_codes code)
322{
323 ft_send_resp_code(cmd, code);
324 ft_free_cmd(cmd);
325}
326
327/*
328 * Handle Task Management Request.
329 */
330static void ft_send_tm(struct ft_cmd *cmd)
331{
332 struct fcp_cmnd *fcp;
333 int rc;
334 u8 tm_func;
335
336 fcp = fc_frame_payload_get(fp: cmd->req_frame, len: sizeof(*fcp));
337
338 switch (fcp->fc_tm_flags) {
339 case FCP_TMF_LUN_RESET:
340 tm_func = TMR_LUN_RESET;
341 break;
342 case FCP_TMF_TGT_RESET:
343 tm_func = TMR_TARGET_WARM_RESET;
344 break;
345 case FCP_TMF_CLR_TASK_SET:
346 tm_func = TMR_CLEAR_TASK_SET;
347 break;
348 case FCP_TMF_ABT_TASK_SET:
349 tm_func = TMR_ABORT_TASK_SET;
350 break;
351 case FCP_TMF_CLR_ACA:
352 tm_func = TMR_CLEAR_ACA;
353 break;
354 default:
355 /*
356 * FCP4r01 indicates having a combination of
357 * tm_flags set is invalid.
358 */
359 pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
360 ft_send_resp_code_and_free(cmd, code: FCP_CMND_FIELDS_INVALID);
361 return;
362 }
363
364 /* FIXME: Add referenced task tag for ABORT_TASK */
365 rc = target_submit_tmr(se_cmd: &cmd->se_cmd, se_sess: cmd->sess->se_sess,
366 sense: &cmd->ft_sense_buffer[0], unpacked_lun: scsilun_to_int(&fcp->fc_lun),
367 fabric_tmr_ptr: cmd, tm_type: tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
368 if (rc < 0)
369 ft_send_resp_code_and_free(cmd, code: FCP_TMF_FAILED);
370}
371
372/*
373 * Send status from completed task management request.
374 */
375void ft_queue_tm_resp(struct se_cmd *se_cmd)
376{
377 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
378 struct se_tmr_req *tmr = se_cmd->se_tmr_req;
379 enum fcp_resp_rsp_codes code;
380
381 if (cmd->aborted)
382 return;
383 switch (tmr->response) {
384 case TMR_FUNCTION_COMPLETE:
385 code = FCP_TMF_CMPL;
386 break;
387 case TMR_LUN_DOES_NOT_EXIST:
388 code = FCP_TMF_INVALID_LUN;
389 break;
390 case TMR_FUNCTION_REJECTED:
391 code = FCP_TMF_REJECTED;
392 break;
393 case TMR_TASK_DOES_NOT_EXIST:
394 case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
395 default:
396 code = FCP_TMF_FAILED;
397 break;
398 }
399 pr_debug("tmr fn %d resp %d fcp code %d\n",
400 tmr->function, tmr->response, code);
401 ft_send_resp_code(cmd, code);
402 /*
403 * Drop the extra ACK_KREF reference taken by target_submit_tmr()
404 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
405 * final se_cmd->cmd_kref put.
406 */
407 target_put_sess_cmd(&cmd->se_cmd);
408}
409
410void ft_aborted_task(struct se_cmd *se_cmd)
411{
412 return;
413}
414
415static void ft_send_work(struct work_struct *work);
416
417/*
418 * Handle incoming FCP command.
419 */
420static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
421{
422 struct ft_cmd *cmd;
423 struct fc_lport *lport = sess->tport->lport;
424 struct se_session *se_sess = sess->se_sess;
425 int tag, cpu;
426
427 tag = sbitmap_queue_get(sbq: &se_sess->sess_tag_pool, cpu: &cpu);
428 if (tag < 0)
429 goto busy;
430
431 cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
432 memset(cmd, 0, sizeof(struct ft_cmd));
433
434 cmd->se_cmd.map_tag = tag;
435 cmd->se_cmd.map_cpu = cpu;
436 cmd->sess = sess;
437 cmd->seq = fc_seq_assign(lport, fp);
438 if (!cmd->seq) {
439 target_free_tag(sess: se_sess, cmd: &cmd->se_cmd);
440 goto busy;
441 }
442 cmd->req_frame = fp; /* hold frame during cmd */
443
444 INIT_WORK(&cmd->work, ft_send_work);
445 queue_work(wq: sess->tport->tpg->workqueue, work: &cmd->work);
446 return;
447
448busy:
449 pr_debug("cmd or seq allocation failure - sending BUSY\n");
450 ft_send_resp_status(lport, rx_fp: fp, status: SAM_STAT_BUSY, code: 0);
451 fc_frame_free(fp);
452 ft_sess_put(sess); /* undo get from lookup */
453}
454
455
456/*
457 * Handle incoming FCP frame.
458 * Caller has verified that the frame is type FCP.
459 */
460void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
461{
462 struct fc_frame_header *fh = fc_frame_header_get(fp);
463
464 switch (fh->fh_r_ctl) {
465 case FC_RCTL_DD_UNSOL_CMD: /* command */
466 ft_recv_cmd(sess, fp);
467 break;
468 case FC_RCTL_DD_SOL_DATA: /* write data */
469 case FC_RCTL_DD_UNSOL_CTL:
470 case FC_RCTL_DD_SOL_CTL:
471 case FC_RCTL_DD_DATA_DESC: /* transfer ready */
472 case FC_RCTL_ELS4_REQ: /* SRR, perhaps */
473 default:
474 pr_debug("%s: unhandled frame r_ctl %x\n",
475 __func__, fh->fh_r_ctl);
476 fc_frame_free(fp);
477 ft_sess_put(sess); /* undo get from lookup */
478 break;
479 }
480}
481
482/*
483 * Send new command to target.
484 */
485static void ft_send_work(struct work_struct *work)
486{
487 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
488 struct fc_frame_header *fh = fc_frame_header_get(fp: cmd->req_frame);
489 struct fcp_cmnd *fcp;
490 int data_dir = 0;
491 int task_attr;
492
493 fcp = fc_frame_payload_get(fp: cmd->req_frame, len: sizeof(*fcp));
494 if (!fcp)
495 goto err;
496
497 if (fcp->fc_flags & FCP_CFL_LEN_MASK)
498 goto err; /* not handling longer CDBs yet */
499
500 /*
501 * Check for FCP task management flags
502 */
503 if (fcp->fc_tm_flags) {
504 ft_send_tm(cmd);
505 return;
506 }
507
508 switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
509 case 0:
510 data_dir = DMA_NONE;
511 break;
512 case FCP_CFL_RDDATA:
513 data_dir = DMA_FROM_DEVICE;
514 break;
515 case FCP_CFL_WRDATA:
516 data_dir = DMA_TO_DEVICE;
517 break;
518 case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
519 goto err; /* TBD not supported by tcm_fc yet */
520 }
521 /*
522 * Locate the SAM Task Attr from fc_pri_ta
523 */
524 switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
525 case FCP_PTA_HEADQ:
526 task_attr = TCM_HEAD_TAG;
527 break;
528 case FCP_PTA_ORDERED:
529 task_attr = TCM_ORDERED_TAG;
530 break;
531 case FCP_PTA_ACA:
532 task_attr = TCM_ACA_TAG;
533 break;
534 case FCP_PTA_SIMPLE:
535 default:
536 task_attr = TCM_SIMPLE_TAG;
537 }
538
539 fc_seq_set_resp(sp: cmd->seq, resp: ft_recv_seq, arg: cmd);
540 cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
541
542 /*
543 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
544 * directly from ft_check_stop_free callback in response path.
545 */
546 if (target_init_cmd(se_cmd: &cmd->se_cmd, se_sess: cmd->sess->se_sess,
547 sense: &cmd->ft_sense_buffer[0],
548 unpacked_lun: scsilun_to_int(&fcp->fc_lun), ntohl(fcp->fc_dl),
549 task_attr, data_dir, flags: TARGET_SCF_ACK_KREF))
550 goto err;
551
552 if (target_submit_prep(se_cmd: &cmd->se_cmd, cdb: fcp->fc_cdb, NULL, sgl_count: 0, NULL, sgl_bidi_count: 0,
553 NULL, sgl_prot_count: 0, GFP_KERNEL))
554 return;
555
556 target_submit(se_cmd: &cmd->se_cmd);
557 pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
558 return;
559
560err:
561 ft_send_resp_code_and_free(cmd, code: FCP_CMND_FIELDS_INVALID);
562}
563

source code of linux/drivers/target/tcm_fc/tfc_cmd.c