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 #include <scsi/fc_encode.h>
32
33 #include <target/target_core_base.h>
34 #include <target/target_core_fabric.h>
35
36 #include "tcm_fc.h"
37
38 /*
39 * Deliver read data back to initiator.
40 * XXX TBD handle resource problems later.
41 */
42 int ft_queue_data_in(struct se_cmd *se_cmd)
43 {
44 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
45 struct fc_frame *fp = NULL;
46 struct fc_exch *ep;
47 struct fc_lport *lport;
48 struct scatterlist *sg = NULL;
49 size_t remaining;
50 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
51 u32 mem_off = 0;
52 u32 fh_off = 0;
53 u32 frame_off = 0;
54 size_t frame_len = 0;
55 size_t mem_len = 0;
56 size_t tlen;
57 size_t off_in_page;
58 struct page *page = NULL;
59 int use_sg;
60 int error;
61 void *page_addr;
62 void *from;
63 void *to = NULL;
64
65 if (cmd->aborted)
66 return 0;
67
68 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
69 goto queue_status;
70
71 ep = fc_seq_exch(cmd->seq);
72 lport = ep->lp;
73 cmd->seq = fc_seq_start_next(cmd->seq);
74
75 remaining = se_cmd->data_length;
76
77 /*
78 * Setup to use first mem list entry, unless no data.
79 */
80 BUG_ON(remaining && !se_cmd->t_data_sg);
81 if (remaining) {
82 sg = se_cmd->t_data_sg;
83 mem_len = sg->length;
84 mem_off = sg->offset;
85 page = sg_page(sg);
86 }
87
88 /* no scatter/gather in skb for odd word length due to fc_seq_send() */
89 use_sg = !(remaining % 4);
90
91 while (remaining) {
92 struct fc_seq *seq = cmd->seq;
93
94 if (!seq) {
95 pr_debug("%s: Command aborted, xid 0x%x\n",
96 __func__, ep->xid);
97 break;
98 }
99 if (!mem_len) {
100 sg = sg_next(sg);
101 mem_len = min((size_t)sg->length, remaining);
102 mem_off = sg->offset;
103 page = sg_page(sg);
104 }
105 if (!frame_len) {
106 /*
107 * If lport's has capability of Large Send Offload LSO)
108 * , then allow 'frame_len' to be as big as 'lso_max'
109 * if indicated transfer length is >= lport->lso_max
110 */
111 frame_len = (lport->seq_offload) ? lport->lso_max :
112 cmd->sess->max_frame;
113 frame_len = min(frame_len, remaining);
114 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
115 if (!fp)
116 return -ENOMEM;
117 to = fc_frame_payload_get(fp, 0);
118 fh_off = frame_off;
119 frame_off += frame_len;
120 /*
121 * Setup the frame's max payload which is used by base
122 * driver to indicate HW about max frame size, so that
123 * HW can do fragmentation appropriately based on
124 * "gso_max_size" of underline netdev.
125 */
126 fr_max_payload(fp) = cmd->sess->max_frame;
127 }
128 tlen = min(mem_len, frame_len);
129
130 if (use_sg) {
131 off_in_page = mem_off;
132 BUG_ON(!page);
133 get_page(page);
134 skb_fill_page_desc(fp_skb(fp),
135 skb_shinfo(fp_skb(fp))->nr_frags,
136 page, off_in_page, tlen);
137 fr_len(fp) += tlen;
138 fp_skb(fp)->data_len += tlen;
139 fp_skb(fp)->truesize += page_size(page);
140 } else {
141 BUG_ON(!page);
142 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
143 page_addr = from;
144 from += offset_in_page(mem_off);
145 tlen = min(tlen, (size_t)(PAGE_SIZE -
146 offset_in_page(mem_off)));
147 memcpy(to, from, tlen);
148 kunmap_atomic(page_addr);
149 to += tlen;
150 }
151
152 mem_off += tlen;
153 mem_len -= tlen;
154 frame_len -= tlen;
155 remaining -= tlen;
156
157 if (frame_len &&
158 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
159 continue;
160 if (!remaining)
161 f_ctl |= FC_FC_END_SEQ;
162 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
163 FC_TYPE_FCP, f_ctl, fh_off);
164 error = fc_seq_send(lport, seq, fp);
165 if (error) {
166 pr_info_ratelimited("%s: Failed to send frame %p, "
167 "xid <0x%x>, remaining %zu, "
168 "lso_max <0x%x>\n",
169 __func__, fp, ep->xid,
170 remaining, lport->lso_max);
171 /*
172 * Go ahead and set TASK_SET_FULL status ignoring the
173 * rest of the DataIN, and immediately attempt to
174 * send the response via ft_queue_status() in order
175 * to notify the initiator that it should reduce it's
176 * per LUN queue_depth.
177 */
178 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
179 break;
180 }
181 }
182 queue_status:
183 return ft_queue_status(se_cmd);
184 }
185
186 static void ft_execute_work(struct work_struct *work)
187 {
188 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
189
190 target_execute_cmd(&cmd->se_cmd);
191 }
192
193 /*
194 * Receive write data frame.
195 */
196 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
197 {
198 struct se_cmd *se_cmd = &cmd->se_cmd;
199 struct fc_seq *seq = cmd->seq;
200 struct fc_exch *ep;
201 struct fc_lport *lport;
202 struct fc_frame_header *fh;
203 struct scatterlist *sg = NULL;
204 u32 mem_off = 0;
205 u32 rel_off;
206 size_t frame_len;
207 size_t mem_len = 0;
208 size_t tlen;
209 struct page *page = NULL;
210 void *page_addr;
211 void *from;
212 void *to;
213 u32 f_ctl;
214 void *buf;
215
216 fh = fc_frame_header_get(fp);
217 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
218 goto drop;
219
220 f_ctl = ntoh24(fh->fh_f_ctl);
221 ep = fc_seq_exch(seq);
222 lport = ep->lp;
223 if (cmd->was_ddp_setup) {
224 BUG_ON(!ep);
225 BUG_ON(!lport);
226 /*
227 * Since DDP (Large Rx offload) was setup for this request,
228 * payload is expected to be copied directly to user buffers.
229 */
230 buf = fc_frame_payload_get(fp, 1);
231 if (buf)
232 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
233 "cmd->sg_cnt 0x%x. DDP was setup"
234 " hence not expected to receive frame with "
235 "payload, Frame will be dropped if"
236 "'Sequence Initiative' bit in f_ctl is"
237 "not set\n", __func__, ep->xid, f_ctl,
238 se_cmd->t_data_sg, se_cmd->t_data_nents);
239 /*
240 * Invalidate HW DDP context if it was setup for respective
241 * command. Invalidation of HW DDP context is requited in both
242 * situation (success and error).
243 */
244 ft_invl_hw_context(cmd);
245
246 /*
247 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
248 * write data frame is received successfully where payload is
249 * posted directly to user buffer and only the last frame's
250 * header is posted in receive queue.
251 *
252 * If "Sequence Initiative (TSI)" bit is not set, means error
253 * condition w.r.t. DDP, hence drop the packet and let explict
254 * ABORTS from other end of exchange timer trigger the recovery.
255 */
256 if (f_ctl & FC_FC_SEQ_INIT)
257 goto last_frame;
258 else
259 goto drop;
260 }
261
262 rel_off = ntohl(fh->fh_parm_offset);
263 frame_len = fr_len(fp);
264 if (frame_len <= sizeof(*fh))
265 goto drop;
266 frame_len -= sizeof(*fh);
267 from = fc_frame_payload_get(fp, 0);
268 if (rel_off >= se_cmd->data_length)
269 goto drop;
270 if (frame_len + rel_off > se_cmd->data_length)
271 frame_len = se_cmd->data_length - rel_off;
272
273 /*
274 * Setup to use first mem list entry, unless no data.
275 */
276 BUG_ON(frame_len && !se_cmd->t_data_sg);
277 if (frame_len) {
278 sg = se_cmd->t_data_sg;
279 mem_len = sg->length;
280 mem_off = sg->offset;
281 page = sg_page(sg);
282 }
283
284 while (frame_len) {
285 if (!mem_len) {
286 sg = sg_next(sg);
287 mem_len = sg->length;
288 mem_off = sg->offset;
289 page = sg_page(sg);
290 }
291 if (rel_off >= mem_len) {
292 rel_off -= mem_len;
293 mem_len = 0;
294 continue;
295 }
296 mem_off += rel_off;
297 mem_len -= rel_off;
298 rel_off = 0;
299
300 tlen = min(mem_len, frame_len);
301
302 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
303 page_addr = to;
304 to += offset_in_page(mem_off);
305 tlen = min(tlen, (size_t)(PAGE_SIZE -
306 offset_in_page(mem_off)));
307 memcpy(to, from, tlen);
308 kunmap_atomic(page_addr);
309
310 from += tlen;
311 frame_len -= tlen;
312 mem_off += tlen;
313 mem_len -= tlen;
314 cmd->write_data_len += tlen;
315 }
316 last_frame:
317 if (cmd->write_data_len == se_cmd->data_length) {
318 INIT_WORK(&cmd->work, ft_execute_work);
319 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
320 }
321 drop:
322 fc_frame_free(fp);
323 }
324
325 /*
326 * Handle and cleanup any HW specific resources if
327 * received ABORTS, errors, timeouts.
328 */
329 void ft_invl_hw_context(struct ft_cmd *cmd)
330 {
331 struct fc_seq *seq;
332 struct fc_exch *ep = NULL;
333 struct fc_lport *lport = NULL;
334
335 BUG_ON(!cmd);
336 seq = cmd->seq;
337
338 /* Cleanup the DDP context in HW if DDP was setup */
339 if (cmd->was_ddp_setup && seq) {
340 ep = fc_seq_exch(seq);
341 if (ep) {
342 lport = ep->lp;
343 if (lport && (ep->xid <= lport->lro_xid)) {
344 /*
345 * "ddp_done" trigger invalidation of HW
346 * specific DDP context
347 */
348 cmd->write_data_len = lport->tt.ddp_done(lport,
349 ep->xid);
350
351 /*
352 * Resetting same variable to indicate HW's
353 * DDP context has been invalidated to avoid
354 * re_invalidation of same context (context is
355 * identified using ep->xid)
356 */
357 cmd->was_ddp_setup = 0;
358 }
359 }
360 }
361 }