1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2010 Cisco Systems, Inc.
4 *
5 * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
6 *
7 * Copyright (c) 2007 Intel Corporation. All rights reserved.
8 * Copyright (c) 2008 Red Hat, Inc. All rights reserved.
9 * Copyright (c) 2008 Mike Christie
10 * Copyright (c) 2009 Rising Tide, Inc.
11 * Copyright (c) 2009 Linux-iSCSI.org
12 * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
13 */
14
15/* XXX TBD some includes may be extraneous */
16
17#include <linux/module.h>
18#include <linux/moduleparam.h>
19#include <linux/utsname.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/kthread.h>
23#include <linux/types.h>
24#include <linux/string.h>
25#include <linux/configfs.h>
26#include <linux/ctype.h>
27#include <linux/hash.h>
28#include <linux/ratelimit.h>
29#include <asm/unaligned.h>
30#include <scsi/libfc.h>
31
32#include <target/target_core_base.h>
33#include <target/target_core_fabric.h>
34
35#include "tcm_fc.h"
36
37/*
38 * Deliver read data back to initiator.
39 * XXX TBD handle resource problems later.
40 */
41int ft_queue_data_in(struct se_cmd *se_cmd)
42{
43 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
44 struct fc_frame *fp = NULL;
45 struct fc_exch *ep;
46 struct fc_lport *lport;
47 struct scatterlist *sg = NULL;
48 size_t remaining;
49 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
50 u32 mem_off = 0;
51 u32 fh_off = 0;
52 u32 frame_off = 0;
53 size_t frame_len = 0;
54 size_t mem_len = 0;
55 size_t tlen;
56 size_t off_in_page;
57 struct page *page = NULL;
58 int use_sg;
59 int error;
60 void *page_addr;
61 void *from;
62 void *to = NULL;
63
64 if (cmd->aborted)
65 return 0;
66
67 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
68 goto queue_status;
69
70 ep = fc_seq_exch(cmd->seq);
71 lport = ep->lp;
72 cmd->seq = fc_seq_start_next(sp: cmd->seq);
73
74 remaining = se_cmd->data_length;
75
76 /*
77 * Setup to use first mem list entry, unless no data.
78 */
79 BUG_ON(remaining && !se_cmd->t_data_sg);
80 if (remaining) {
81 sg = se_cmd->t_data_sg;
82 mem_len = sg->length;
83 mem_off = sg->offset;
84 page = sg_page(sg);
85 }
86
87 /* no scatter/gather in skb for odd word length due to fc_seq_send() */
88 use_sg = !(remaining % 4);
89
90 while (remaining) {
91 struct fc_seq *seq = cmd->seq;
92
93 if (!seq) {
94 pr_debug("%s: Command aborted, xid 0x%x\n",
95 __func__, ep->xid);
96 break;
97 }
98 if (!mem_len) {
99 sg = sg_next(sg);
100 mem_len = min((size_t)sg->length, remaining);
101 mem_off = sg->offset;
102 page = sg_page(sg);
103 }
104 if (!frame_len) {
105 /*
106 * If lport's has capability of Large Send Offload LSO)
107 * , then allow 'frame_len' to be as big as 'lso_max'
108 * if indicated transfer length is >= lport->lso_max
109 */
110 frame_len = (lport->seq_offload) ? lport->lso_max :
111 cmd->sess->max_frame;
112 frame_len = min(frame_len, remaining);
113 fp = fc_frame_alloc(dev: lport, len: use_sg ? 0 : frame_len);
114 if (!fp)
115 return -ENOMEM;
116 to = fc_frame_payload_get(fp, len: 0);
117 fh_off = frame_off;
118 frame_off += frame_len;
119 /*
120 * Setup the frame's max payload which is used by base
121 * driver to indicate HW about max frame size, so that
122 * HW can do fragmentation appropriately based on
123 * "gso_max_size" of underline netdev.
124 */
125 fr_max_payload(fp) = cmd->sess->max_frame;
126 }
127 tlen = min(mem_len, frame_len);
128
129 if (use_sg) {
130 off_in_page = mem_off;
131 BUG_ON(!page);
132 get_page(page);
133 skb_fill_page_desc(fp_skb(fp),
134 skb_shinfo(fp_skb(fp))->nr_frags,
135 page, off: off_in_page, size: tlen);
136 fr_len(fp) += tlen;
137 fp_skb(fp)->data_len += tlen;
138 fp_skb(fp)->truesize += page_size(page);
139 } else {
140 BUG_ON(!page);
141 from = kmap_atomic(page: page + (mem_off >> PAGE_SHIFT));
142 page_addr = from;
143 from += offset_in_page(mem_off);
144 tlen = min(tlen, (size_t)(PAGE_SIZE -
145 offset_in_page(mem_off)));
146 memcpy(to, from, tlen);
147 kunmap_atomic(page_addr);
148 to += tlen;
149 }
150
151 mem_off += tlen;
152 mem_len -= tlen;
153 frame_len -= tlen;
154 remaining -= tlen;
155
156 if (frame_len &&
157 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
158 continue;
159 if (!remaining)
160 f_ctl |= FC_FC_END_SEQ;
161 fc_fill_fc_hdr(fp, r_ctl: FC_RCTL_DD_SOL_DATA, did: ep->did, sid: ep->sid,
162 type: FC_TYPE_FCP, f_ctl, parm_offset: fh_off);
163 error = fc_seq_send(lport, sp: seq, fp);
164 if (error) {
165 pr_info_ratelimited("%s: Failed to send frame %p, "
166 "xid <0x%x>, remaining %zu, "
167 "lso_max <0x%x>\n",
168 __func__, fp, ep->xid,
169 remaining, lport->lso_max);
170 /*
171 * Go ahead and set TASK_SET_FULL status ignoring the
172 * rest of the DataIN, and immediately attempt to
173 * send the response via ft_queue_status() in order
174 * to notify the initiator that it should reduce it's
175 * per LUN queue_depth.
176 */
177 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
178 break;
179 }
180 }
181queue_status:
182 return ft_queue_status(se_cmd);
183}
184
185static void ft_execute_work(struct work_struct *work)
186{
187 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
188
189 target_execute_cmd(cmd: &cmd->se_cmd);
190}
191
192/*
193 * Receive write data frame.
194 */
195void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
196{
197 struct se_cmd *se_cmd = &cmd->se_cmd;
198 struct fc_seq *seq = cmd->seq;
199 struct fc_exch *ep;
200 struct fc_lport *lport;
201 struct fc_frame_header *fh;
202 struct scatterlist *sg = NULL;
203 u32 mem_off = 0;
204 u32 rel_off;
205 size_t frame_len;
206 size_t mem_len = 0;
207 size_t tlen;
208 struct page *page = NULL;
209 void *page_addr;
210 void *from;
211 void *to;
212 u32 f_ctl;
213 void *buf;
214
215 fh = fc_frame_header_get(fp);
216 if (!(ntoh24(p: fh->fh_f_ctl) & FC_FC_REL_OFF))
217 goto drop;
218
219 f_ctl = ntoh24(p: fh->fh_f_ctl);
220 ep = fc_seq_exch(seq);
221 lport = ep->lp;
222 if (cmd->was_ddp_setup) {
223 BUG_ON(!lport);
224 /*
225 * Since DDP (Large Rx offload) was setup for this request,
226 * payload is expected to be copied directly to user buffers.
227 */
228 buf = fc_frame_payload_get(fp, len: 1);
229 if (buf)
230 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
231 "cmd->sg_cnt 0x%x. DDP was setup"
232 " hence not expected to receive frame with "
233 "payload, Frame will be dropped if"
234 "'Sequence Initiative' bit in f_ctl is"
235 "not set\n", __func__, ep->xid, f_ctl,
236 se_cmd->t_data_sg, se_cmd->t_data_nents);
237 /*
238 * Invalidate HW DDP context if it was setup for respective
239 * command. Invalidation of HW DDP context is requited in both
240 * situation (success and error).
241 */
242 ft_invl_hw_context(cmd);
243
244 /*
245 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
246 * write data frame is received successfully where payload is
247 * posted directly to user buffer and only the last frame's
248 * header is posted in receive queue.
249 *
250 * If "Sequence Initiative (TSI)" bit is not set, means error
251 * condition w.r.t. DDP, hence drop the packet and let explict
252 * ABORTS from other end of exchange timer trigger the recovery.
253 */
254 if (f_ctl & FC_FC_SEQ_INIT)
255 goto last_frame;
256 else
257 goto drop;
258 }
259
260 rel_off = ntohl(fh->fh_parm_offset);
261 frame_len = fr_len(fp);
262 if (frame_len <= sizeof(*fh))
263 goto drop;
264 frame_len -= sizeof(*fh);
265 from = fc_frame_payload_get(fp, len: 0);
266 if (rel_off >= se_cmd->data_length)
267 goto drop;
268 if (frame_len + rel_off > se_cmd->data_length)
269 frame_len = se_cmd->data_length - rel_off;
270
271 /*
272 * Setup to use first mem list entry, unless no data.
273 */
274 BUG_ON(frame_len && !se_cmd->t_data_sg);
275 if (frame_len) {
276 sg = se_cmd->t_data_sg;
277 mem_len = sg->length;
278 mem_off = sg->offset;
279 page = sg_page(sg);
280 }
281
282 while (frame_len) {
283 if (!mem_len) {
284 sg = sg_next(sg);
285 mem_len = sg->length;
286 mem_off = sg->offset;
287 page = sg_page(sg);
288 }
289 if (rel_off >= mem_len) {
290 rel_off -= mem_len;
291 mem_len = 0;
292 continue;
293 }
294 mem_off += rel_off;
295 mem_len -= rel_off;
296 rel_off = 0;
297
298 tlen = min(mem_len, frame_len);
299
300 to = kmap_atomic(page: page + (mem_off >> PAGE_SHIFT));
301 page_addr = to;
302 to += offset_in_page(mem_off);
303 tlen = min(tlen, (size_t)(PAGE_SIZE -
304 offset_in_page(mem_off)));
305 memcpy(to, from, tlen);
306 kunmap_atomic(page_addr);
307
308 from += tlen;
309 frame_len -= tlen;
310 mem_off += tlen;
311 mem_len -= tlen;
312 cmd->write_data_len += tlen;
313 }
314last_frame:
315 if (cmd->write_data_len == se_cmd->data_length) {
316 INIT_WORK(&cmd->work, ft_execute_work);
317 queue_work(wq: cmd->sess->tport->tpg->workqueue, work: &cmd->work);
318 }
319drop:
320 fc_frame_free(fp);
321}
322
323/*
324 * Handle and cleanup any HW specific resources if
325 * received ABORTS, errors, timeouts.
326 */
327void ft_invl_hw_context(struct ft_cmd *cmd)
328{
329 struct fc_seq *seq;
330 struct fc_exch *ep = NULL;
331 struct fc_lport *lport = NULL;
332
333 BUG_ON(!cmd);
334 seq = cmd->seq;
335
336 /* Cleanup the DDP context in HW if DDP was setup */
337 if (cmd->was_ddp_setup && seq) {
338 ep = fc_seq_exch(seq);
339 if (ep) {
340 lport = ep->lp;
341 if (lport && (ep->xid <= lport->lro_xid)) {
342 /*
343 * "ddp_done" trigger invalidation of HW
344 * specific DDP context
345 */
346 cmd->write_data_len = lport->tt.ddp_done(lport,
347 ep->xid);
348
349 /*
350 * Resetting same variable to indicate HW's
351 * DDP context has been invalidated to avoid
352 * re_invalidation of same context (context is
353 * identified using ep->xid)
354 */
355 cmd->was_ddp_setup = 0;
356 }
357 }
358 }
359}
360

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