summaryrefslogtreecommitdiff
path: root/drivers/target/tcm_fc/tfc_io.c
blob: 8e2a46ddcccb5b5ce808b1545e7c91afb741d56a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
/*
 * Copyright (c) 2010 Cisco Systems, Inc.
 *
 * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
 *
 * Copyright (c) 2007 Intel Corporation. All rights reserved.
 * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
 * Copyright (c) 2008 Mike Christie
 * Copyright (c) 2009 Rising Tide, Inc.
 * Copyright (c) 2009 Linux-iSCSI.org
 * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* XXX TBD some includes may be extraneous */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/version.h>
#include <generated/utsrelease.h>
#include <linux/utsname.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/configfs.h>
#include <linux/ctype.h>
#include <linux/hash.h>
#include <linux/ratelimit.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>

#include <target/target_core_base.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>
#include <target/target_core_device.h>
#include <target/target_core_tpg.h>
#include <target/target_core_configfs.h>
#include <target/configfs_macros.h>

#include "tcm_fc.h"

/*
 * Deliver read data back to initiator.
 * XXX TBD handle resource problems later.
 */
int ft_queue_data_in(struct se_cmd *se_cmd)
{
	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
	struct fc_frame *fp = NULL;
	struct fc_exch *ep;
	struct fc_lport *lport;
	struct scatterlist *sg = NULL;
	size_t remaining;
	u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
	u32 mem_off = 0;
	u32 fh_off = 0;
	u32 frame_off = 0;
	size_t frame_len = 0;
	size_t mem_len = 0;
	size_t tlen;
	size_t off_in_page;
	struct page *page = NULL;
	int use_sg;
	int error;
	void *page_addr;
	void *from;
	void *to = NULL;

	ep = fc_seq_exch(cmd->seq);
	lport = ep->lp;
	cmd->seq = lport->tt.seq_start_next(cmd->seq);

	remaining = se_cmd->data_length;

	/*
	 * Setup to use first mem list entry, unless no data.
	 */
	BUG_ON(remaining && !se_cmd->t_data_sg);
	if (remaining) {
		sg = se_cmd->t_data_sg;
		mem_len = sg->length;
		mem_off = sg->offset;
		page = sg_page(sg);
	}

	/* no scatter/gather in skb for odd word length due to fc_seq_send() */
	use_sg = !(remaining % 4);

	while (remaining) {
		if (!mem_len) {
			sg = sg_next(sg);
			mem_len = min((size_t)sg->length, remaining);
			mem_off = sg->offset;
			page = sg_page(sg);
		}
		if (!frame_len) {
			/*
			 * If lport's has capability of Large Send Offload LSO)
			 * , then allow 'frame_len' to be as big as 'lso_max'
			 * if indicated transfer length is >= lport->lso_max
			 */
			frame_len = (lport->seq_offload) ? lport->lso_max :
							  cmd->sess->max_frame;
			frame_len = min(frame_len, remaining);
			fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
			if (!fp)
				return -ENOMEM;
			to = fc_frame_payload_get(fp, 0);
			fh_off = frame_off;
			frame_off += frame_len;
			/*
			 * Setup the frame's max payload which is used by base
			 * driver to indicate HW about max frame size, so that
			 * HW can do fragmentation appropriately based on
			 * "gso_max_size" of underline netdev.
			 */
			fr_max_payload(fp) = cmd->sess->max_frame;
		}
		tlen = min(mem_len, frame_len);

		if (use_sg) {
			off_in_page = mem_off;
			BUG_ON(!page);
			get_page(page);
			skb_fill_page_desc(fp_skb(fp),
					   skb_shinfo(fp_skb(fp))->nr_frags,
					   page, off_in_page, tlen);
			fr_len(fp) += tlen;
			fp_skb(fp)->data_len += tlen;
			fp_skb(fp)->truesize +=
					PAGE_SIZE << compound_order(page);
		} else {
			BUG_ON(!page);
			from = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
					   KM_SOFTIRQ0);
			page_addr = from;
			from += mem_off & ~PAGE_MASK;
			tlen = min(tlen, (size_t)(PAGE_SIZE -
						(mem_off & ~PAGE_MASK)));
			memcpy(to, from, tlen);
			kunmap_atomic(page_addr, KM_SOFTIRQ0);
			to += tlen;
		}

		mem_off += tlen;
		mem_len -= tlen;
		frame_len -= tlen;
		remaining -= tlen;

		if (frame_len &&
		    (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
			continue;
		if (!remaining)
			f_ctl |= FC_FC_END_SEQ;
		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
			       FC_TYPE_FCP, f_ctl, fh_off);
		error = lport->tt.seq_send(lport, cmd->seq, fp);
		if (error) {
			/* XXX For now, initiator will retry */
			pr_err_ratelimited("%s: Failed to send frame %p, "
						"xid <0x%x>, remaining %zu, "
						"lso_max <0x%x>\n",
						__func__, fp, ep->xid,
						remaining, lport->lso_max);
		}
	}
	return ft_queue_status(se_cmd);
}

/*
 * Receive write data frame.
 */
void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct fc_seq *seq = cmd->seq;
	struct fc_exch *ep;
	struct fc_lport *lport;
	struct fc_frame_header *fh;
	struct scatterlist *sg = NULL;
	u32 mem_off = 0;
	u32 rel_off;
	size_t frame_len;
	size_t mem_len = 0;
	size_t tlen;
	struct page *page = NULL;
	void *page_addr;
	void *from;
	void *to;
	u32 f_ctl;
	void *buf;

	fh = fc_frame_header_get(fp);
	if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
		goto drop;

	/*
	 * Doesn't expect even single byte of payload. Payload
	 * is expected to be copied directly to user buffers
	 * due to DDP (Large Rx offload) feature, hence
	 * BUG_ON if BUF is non-NULL
	 */
	buf = fc_frame_payload_get(fp, 1);
	if (cmd->was_ddp_setup && buf) {
		pr_debug("%s: When DDP was setup, not expected to"
				 "receive frame with payload, Payload shall be"
				 "copied directly to buffer instead of coming "
				 "via. legacy receive queues\n", __func__);
		BUG_ON(buf);
	}

	/*
	 * If ft_cmd indicated 'ddp_setup', in that case only the last frame
	 * should come with 'TSI bit being set'. If 'TSI bit is not set and if
	 * data frame appears here, means error condition. In both the cases
	 * release the DDP context (ddp_put) and in error case, as well
	 * initiate error recovery mechanism.
	 */
	ep = fc_seq_exch(seq);
	if (cmd->was_ddp_setup) {
		BUG_ON(!ep);
		lport = ep->lp;
		BUG_ON(!lport);
	}
	if (cmd->was_ddp_setup && ep->xid != FC_XID_UNKNOWN) {
		f_ctl = ntoh24(fh->fh_f_ctl);
		/*
		 * If TSI bit set in f_ctl, means last write data frame is
		 * received successfully where payload is posted directly
		 * to user buffer and only the last frame's header is posted
		 * in legacy receive queue
		 */
		if (f_ctl & FC_FC_SEQ_INIT) { /* TSI bit set in FC frame */
			cmd->write_data_len = lport->tt.ddp_done(lport,
								ep->xid);
			goto last_frame;
		} else {
			/*
			 * Updating the write_data_len may be meaningless at
			 * this point, but just in case if required in future
			 * for debugging or any other purpose
			 */
			pr_err("%s: Received frame with TSI bit not"
					" being SET, dropping the frame, "
					"cmd->sg <%p>, cmd->sg_cnt <0x%x>\n",
					__func__, cmd->sg, cmd->sg_cnt);
			cmd->write_data_len = lport->tt.ddp_done(lport,
							      ep->xid);
			lport->tt.seq_exch_abort(cmd->seq, 0);
			goto drop;
		}
	}

	rel_off = ntohl(fh->fh_parm_offset);
	frame_len = fr_len(fp);
	if (frame_len <= sizeof(*fh))
		goto drop;
	frame_len -= sizeof(*fh);
	from = fc_frame_payload_get(fp, 0);
	if (rel_off >= se_cmd->data_length)
		goto drop;
	if (frame_len + rel_off > se_cmd->data_length)
		frame_len = se_cmd->data_length - rel_off;

	/*
	 * Setup to use first mem list entry, unless no data.
	 */
	BUG_ON(frame_len && !se_cmd->t_data_sg);
	if (frame_len) {
		sg = se_cmd->t_data_sg;
		mem_len = sg->length;
		mem_off = sg->offset;
		page = sg_page(sg);
	}

	while (frame_len) {
		if (!mem_len) {
			sg = sg_next(sg);
			mem_len = sg->length;
			mem_off = sg->offset;
			page = sg_page(sg);
		}
		if (rel_off >= mem_len) {
			rel_off -= mem_len;
			mem_len = 0;
			continue;
		}
		mem_off += rel_off;
		mem_len -= rel_off;
		rel_off = 0;

		tlen = min(mem_len, frame_len);

		to = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
				 KM_SOFTIRQ0);
		page_addr = to;
		to += mem_off & ~PAGE_MASK;
		tlen = min(tlen, (size_t)(PAGE_SIZE -
					  (mem_off & ~PAGE_MASK)));
		memcpy(to, from, tlen);
		kunmap_atomic(page_addr, KM_SOFTIRQ0);

		from += tlen;
		frame_len -= tlen;
		mem_off += tlen;
		mem_len -= tlen;
		cmd->write_data_len += tlen;
	}
last_frame:
	if (cmd->write_data_len == se_cmd->data_length)
		transport_generic_handle_data(se_cmd);
drop:
	fc_frame_free(fp);
}