summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/libfc/fc_libfc.c
blob: 8d65a51a7598dad8d0a93d326108f0e8a4edfa73 (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
/*
 * Copyright(c) 2009 Intel Corporation. All rights reserved.
 *
 * 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.
 *
 * Maintained at www.Open-FCoE.org
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/crc32.h>
#include <linux/module.h>

#include <scsi/libfc.h>
#include <scsi/fc_encode.h>

#include "fc_libfc.h"

MODULE_AUTHOR("Open-FCoE.org");
MODULE_DESCRIPTION("libfc");
MODULE_LICENSE("GPL v2");

unsigned int fc_debug_logging;
module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");

DEFINE_MUTEX(fc_prov_mutex);
static LIST_HEAD(fc_local_ports);
struct blocking_notifier_head fc_lport_notifier_head =
		BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
EXPORT_SYMBOL(fc_lport_notifier_head);

/*
 * Providers which primarily send requests and PRLIs.
 */
struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
	[0] = &fc_rport_t0_prov,
	[FC_TYPE_FCP] = &fc_rport_fcp_init,
};

/*
 * Providers which receive requests.
 */
struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
	[FC_TYPE_ELS] = &fc_lport_els_prov,
};

/**
 * libfc_init() - Initialize libfc.ko
 */
static int __init libfc_init(void)
{
	int rc = 0;

	rc = fc_setup_fcp();
	if (rc)
		return rc;

	rc = fc_setup_exch_mgr();
	if (rc)
		goto destroy_pkt_cache;

	rc = fc_setup_rport();
	if (rc)
		goto destroy_em;

	return rc;
destroy_em:
	fc_destroy_exch_mgr();
destroy_pkt_cache:
	fc_destroy_fcp();
	return rc;
}
module_init(libfc_init);

/**
 * libfc_exit() - Tear down libfc.ko
 */
static void __exit libfc_exit(void)
{
	fc_destroy_fcp();
	fc_destroy_exch_mgr();
	fc_destroy_rport();
}
module_exit(libfc_exit);

/**
 * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
 *				into a scatter-gather list (SG list).
 *
 * @buf: pointer to the data buffer.
 * @len: the byte-length of the data buffer.
 * @sg: pointer to the pointer of the SG list.
 * @nents: pointer to the remaining number of entries in the SG list.
 * @offset: pointer to the current offset in the SG list.
 * @crc: pointer to the 32-bit crc value.
 *	 If crc is NULL, CRC is not calculated.
 */
u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
			     struct scatterlist *sg,
			     u32 *nents, size_t *offset,
			     u32 *crc)
{
	size_t remaining = len;
	u32 copy_len = 0;

	while (remaining > 0 && sg) {
		size_t off, sg_bytes;
		void *page_addr;

		if (*offset >= sg->length) {
			/*
			 * Check for end and drop resources
			 * from the last iteration.
			 */
			if (!(*nents))
				break;
			--(*nents);
			*offset -= sg->length;
			sg = sg_next(sg);
			continue;
		}
		sg_bytes = min(remaining, sg->length - *offset);

		/*
		 * The scatterlist item may be bigger than PAGE_SIZE,
		 * but we are limited to mapping PAGE_SIZE at a time.
		 */
		off = *offset + sg->offset;
		sg_bytes = min(sg_bytes,
			       (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
		page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
		if (crc)
			*crc = crc32(*crc, buf, sg_bytes);
		memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
		kunmap_atomic(page_addr);
		buf += sg_bytes;
		*offset += sg_bytes;
		remaining -= sg_bytes;
		copy_len += sg_bytes;
	}
	return copy_len;
}

/**
 * fc_fill_hdr() -  fill FC header fields based on request
 * @fp: reply frame containing header to be filled in
 * @in_fp: request frame containing header to use in filling in reply
 * @r_ctl: R_CTL value for header
 * @f_ctl: F_CTL value for header, with 0 pad
 * @seq_cnt: sequence count for the header, ignored if frame has a sequence
 * @parm_offset: parameter / offset value
 */
void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
		 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
{
	struct fc_frame_header *fh;
	struct fc_frame_header *in_fh;
	struct fc_seq *sp;
	u32 fill;

	fh = __fc_frame_header_get(fp);
	in_fh = __fc_frame_header_get(in_fp);

	if (f_ctl & FC_FC_END_SEQ) {
		fill = -fr_len(fp) & 3;
		if (fill) {
			/* TODO, this may be a problem with fragmented skb */
			memset(skb_put(fp_skb(fp), fill), 0, fill);
			f_ctl |= fill;
		}
		fr_eof(fp) = FC_EOF_T;
	} else {
		WARN_ON(fr_len(fp) % 4 != 0);	/* no pad to non last frame */
		fr_eof(fp) = FC_EOF_N;
	}

	fh->fh_r_ctl = r_ctl;
	memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
	memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
	fh->fh_type = in_fh->fh_type;
	hton24(fh->fh_f_ctl, f_ctl);
	fh->fh_ox_id = in_fh->fh_ox_id;
	fh->fh_rx_id = in_fh->fh_rx_id;
	fh->fh_cs_ctl = 0;
	fh->fh_df_ctl = 0;
	fh->fh_parm_offset = htonl(parm_offset);

	sp = fr_seq(in_fp);
	if (sp) {
		fr_seq(fp) = sp;
		fh->fh_seq_id = sp->id;
		seq_cnt = sp->cnt;
	} else {
		fh->fh_seq_id = 0;
	}
	fh->fh_seq_cnt = ntohs(seq_cnt);
	fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
	fr_encaps(fp) = fr_encaps(in_fp);
}
EXPORT_SYMBOL(fc_fill_hdr);

/**
 * fc_fill_reply_hdr() -  fill FC reply header fields based on request
 * @fp: reply frame containing header to be filled in
 * @in_fp: request frame containing header to use in filling in reply
 * @r_ctl: R_CTL value for reply
 * @parm_offset: parameter / offset value
 */
void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
		       enum fc_rctl r_ctl, u32 parm_offset)
{
	struct fc_seq *sp;

	sp = fr_seq(in_fp);
	if (sp)
		fr_seq(fp) = fr_dev(in_fp)->tt.seq_start_next(sp);
	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
}
EXPORT_SYMBOL(fc_fill_reply_hdr);

/**
 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
 * if there is service provider (target provider) registered with libfc
 * for specified "fc_ft_type"
 * @lport: Local port which service_params needs to be modified
 * @type: FC-4 type, such as FC_TYPE_FCP
 */
void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
{
	struct fc4_prov *prov_entry;
	BUG_ON(type >= FC_FC4_PROV_SIZE);
	BUG_ON(!lport);
	prov_entry = fc_passive_prov[type];
	if (type == FC_TYPE_FCP) {
		if (prov_entry && prov_entry->recv)
			lport->service_params |= FCP_SPPF_TARG_FCN;
	}
}

void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg)
{
	struct fc_lport *lport;

	mutex_lock(&fc_prov_mutex);
	list_for_each_entry(lport, &fc_local_ports, lport_list)
		notify(lport, arg);
	mutex_unlock(&fc_prov_mutex);
}
EXPORT_SYMBOL(fc_lport_iterate);

/**
 * fc_fc4_register_provider() - register FC-4 upper-level provider.
 * @type: FC-4 type, such as FC_TYPE_FCP
 * @prov: structure describing provider including ops vector.
 *
 * Returns 0 on success, negative error otherwise.
 */
int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
{
	struct fc4_prov **prov_entry;
	int ret = 0;

	if (type >= FC_FC4_PROV_SIZE)
		return -EINVAL;
	mutex_lock(&fc_prov_mutex);
	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
	if (*prov_entry)
		ret = -EBUSY;
	else
		*prov_entry = prov;
	mutex_unlock(&fc_prov_mutex);
	return ret;
}
EXPORT_SYMBOL(fc_fc4_register_provider);

/**
 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
 * @type: FC-4 type, such as FC_TYPE_FCP
 * @prov: structure describing provider including ops vector.
 */
void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
{
	BUG_ON(type >= FC_FC4_PROV_SIZE);
	mutex_lock(&fc_prov_mutex);
	if (prov->recv)
		rcu_assign_pointer(fc_passive_prov[type], NULL);
	else
		rcu_assign_pointer(fc_active_prov[type], NULL);
	mutex_unlock(&fc_prov_mutex);
	synchronize_rcu();
}
EXPORT_SYMBOL(fc_fc4_deregister_provider);

/**
 * fc_fc4_add_lport() - add new local port to list and run notifiers.
 * @lport:  The new local port.
 */
void fc_fc4_add_lport(struct fc_lport *lport)
{
	mutex_lock(&fc_prov_mutex);
	list_add_tail(&lport->lport_list, &fc_local_ports);
	blocking_notifier_call_chain(&fc_lport_notifier_head,
				     FC_LPORT_EV_ADD, lport);
	mutex_unlock(&fc_prov_mutex);
}

/**
 * fc_fc4_del_lport() - remove local port from list and run notifiers.
 * @lport:  The new local port.
 */
void fc_fc4_del_lport(struct fc_lport *lport)
{
	mutex_lock(&fc_prov_mutex);
	list_del(&lport->lport_list);
	blocking_notifier_call_chain(&fc_lport_notifier_head,
				     FC_LPORT_EV_DEL, lport);
	mutex_unlock(&fc_prov_mutex);
}
OpenPOWER on IntegriCloud