1/*
2 * Copyright(c) 2009 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Maintained at www.Open-FCoE.org
18 */
19
20#include <linux/kernel.h>
21#include <linux/types.h>
22#include <linux/scatterlist.h>
23#include <linux/crc32.h>
24#include <linux/module.h>
25
26#include <scsi/libfc.h>
27#include <scsi/fc_encode.h>
28
29#include "fc_libfc.h"
30
31MODULE_AUTHOR("Open-FCoE.org");
32MODULE_DESCRIPTION("libfc");
33MODULE_LICENSE("GPL v2");
34
35unsigned int fc_debug_logging;
36module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
37MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
38
39DEFINE_MUTEX(fc_prov_mutex);
40static LIST_HEAD(fc_local_ports);
41struct blocking_notifier_head fc_lport_notifier_head =
42		BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
43EXPORT_SYMBOL(fc_lport_notifier_head);
44
45/*
46 * Providers which primarily send requests and PRLIs.
47 */
48struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
49	[0] = &fc_rport_t0_prov,
50	[FC_TYPE_FCP] = &fc_rport_fcp_init,
51};
52
53/*
54 * Providers which receive requests.
55 */
56struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
57	[FC_TYPE_ELS] = &fc_lport_els_prov,
58};
59
60/**
61 * libfc_init() - Initialize libfc.ko
62 */
63static int __init libfc_init(void)
64{
65	int rc = 0;
66
67	rc = fc_setup_fcp();
68	if (rc)
69		return rc;
70
71	rc = fc_setup_exch_mgr();
72	if (rc)
73		goto destroy_pkt_cache;
74
75	rc = fc_setup_rport();
76	if (rc)
77		goto destroy_em;
78
79	return rc;
80destroy_em:
81	fc_destroy_exch_mgr();
82destroy_pkt_cache:
83	fc_destroy_fcp();
84	return rc;
85}
86module_init(libfc_init);
87
88/**
89 * libfc_exit() - Tear down libfc.ko
90 */
91static void __exit libfc_exit(void)
92{
93	fc_destroy_fcp();
94	fc_destroy_exch_mgr();
95	fc_destroy_rport();
96}
97module_exit(libfc_exit);
98
99/**
100 * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
101 *				into a scatter-gather list (SG list).
102 *
103 * @buf: pointer to the data buffer.
104 * @len: the byte-length of the data buffer.
105 * @sg: pointer to the pointer of the SG list.
106 * @nents: pointer to the remaining number of entries in the SG list.
107 * @offset: pointer to the current offset in the SG list.
108 * @crc: pointer to the 32-bit crc value.
109 *	 If crc is NULL, CRC is not calculated.
110 */
111u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
112			     struct scatterlist *sg,
113			     u32 *nents, size_t *offset,
114			     u32 *crc)
115{
116	size_t remaining = len;
117	u32 copy_len = 0;
118
119	while (remaining > 0 && sg) {
120		size_t off, sg_bytes;
121		void *page_addr;
122
123		if (*offset >= sg->length) {
124			/*
125			 * Check for end and drop resources
126			 * from the last iteration.
127			 */
128			if (!(*nents))
129				break;
130			--(*nents);
131			*offset -= sg->length;
132			sg = sg_next(sg);
133			continue;
134		}
135		sg_bytes = min(remaining, sg->length - *offset);
136
137		/*
138		 * The scatterlist item may be bigger than PAGE_SIZE,
139		 * but we are limited to mapping PAGE_SIZE at a time.
140		 */
141		off = *offset + sg->offset;
142		sg_bytes = min(sg_bytes,
143			       (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
144		page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
145		if (crc)
146			*crc = crc32(*crc, buf, sg_bytes);
147		memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
148		kunmap_atomic(page_addr);
149		buf += sg_bytes;
150		*offset += sg_bytes;
151		remaining -= sg_bytes;
152		copy_len += sg_bytes;
153	}
154	return copy_len;
155}
156
157/**
158 * fc_fill_hdr() -  fill FC header fields based on request
159 * @fp: reply frame containing header to be filled in
160 * @in_fp: request frame containing header to use in filling in reply
161 * @r_ctl: R_CTL value for header
162 * @f_ctl: F_CTL value for header, with 0 pad
163 * @seq_cnt: sequence count for the header, ignored if frame has a sequence
164 * @parm_offset: parameter / offset value
165 */
166void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
167		 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
168{
169	struct fc_frame_header *fh;
170	struct fc_frame_header *in_fh;
171	struct fc_seq *sp;
172	u32 fill;
173
174	fh = __fc_frame_header_get(fp);
175	in_fh = __fc_frame_header_get(in_fp);
176
177	if (f_ctl & FC_FC_END_SEQ) {
178		fill = -fr_len(fp) & 3;
179		if (fill) {
180			/* TODO, this may be a problem with fragmented skb */
181			memset(skb_put(fp_skb(fp), fill), 0, fill);
182			f_ctl |= fill;
183		}
184		fr_eof(fp) = FC_EOF_T;
185	} else {
186		WARN_ON(fr_len(fp) % 4 != 0);	/* no pad to non last frame */
187		fr_eof(fp) = FC_EOF_N;
188	}
189
190	fh->fh_r_ctl = r_ctl;
191	memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
192	memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
193	fh->fh_type = in_fh->fh_type;
194	hton24(fh->fh_f_ctl, f_ctl);
195	fh->fh_ox_id = in_fh->fh_ox_id;
196	fh->fh_rx_id = in_fh->fh_rx_id;
197	fh->fh_cs_ctl = 0;
198	fh->fh_df_ctl = 0;
199	fh->fh_parm_offset = htonl(parm_offset);
200
201	sp = fr_seq(in_fp);
202	if (sp) {
203		fr_seq(fp) = sp;
204		fh->fh_seq_id = sp->id;
205		seq_cnt = sp->cnt;
206	} else {
207		fh->fh_seq_id = 0;
208	}
209	fh->fh_seq_cnt = ntohs(seq_cnt);
210	fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
211	fr_encaps(fp) = fr_encaps(in_fp);
212}
213EXPORT_SYMBOL(fc_fill_hdr);
214
215/**
216 * fc_fill_reply_hdr() -  fill FC reply header fields based on request
217 * @fp: reply frame containing header to be filled in
218 * @in_fp: request frame containing header to use in filling in reply
219 * @r_ctl: R_CTL value for reply
220 * @parm_offset: parameter / offset value
221 */
222void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
223		       enum fc_rctl r_ctl, u32 parm_offset)
224{
225	struct fc_seq *sp;
226
227	sp = fr_seq(in_fp);
228	if (sp)
229		fr_seq(fp) = fr_dev(in_fp)->tt.seq_start_next(sp);
230	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
231}
232EXPORT_SYMBOL(fc_fill_reply_hdr);
233
234/**
235 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
236 * if there is service provider (target provider) registered with libfc
237 * for specified "fc_ft_type"
238 * @lport: Local port which service_params needs to be modified
239 * @type: FC-4 type, such as FC_TYPE_FCP
240 */
241void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
242{
243	struct fc4_prov *prov_entry;
244	BUG_ON(type >= FC_FC4_PROV_SIZE);
245	BUG_ON(!lport);
246	prov_entry = fc_passive_prov[type];
247	if (type == FC_TYPE_FCP) {
248		if (prov_entry && prov_entry->recv)
249			lport->service_params |= FCP_SPPF_TARG_FCN;
250	}
251}
252
253void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg)
254{
255	struct fc_lport *lport;
256
257	mutex_lock(&fc_prov_mutex);
258	list_for_each_entry(lport, &fc_local_ports, lport_list)
259		notify(lport, arg);
260	mutex_unlock(&fc_prov_mutex);
261}
262EXPORT_SYMBOL(fc_lport_iterate);
263
264/**
265 * fc_fc4_register_provider() - register FC-4 upper-level provider.
266 * @type: FC-4 type, such as FC_TYPE_FCP
267 * @prov: structure describing provider including ops vector.
268 *
269 * Returns 0 on success, negative error otherwise.
270 */
271int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
272{
273	struct fc4_prov **prov_entry;
274	int ret = 0;
275
276	if (type >= FC_FC4_PROV_SIZE)
277		return -EINVAL;
278	mutex_lock(&fc_prov_mutex);
279	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
280	if (*prov_entry)
281		ret = -EBUSY;
282	else
283		*prov_entry = prov;
284	mutex_unlock(&fc_prov_mutex);
285	return ret;
286}
287EXPORT_SYMBOL(fc_fc4_register_provider);
288
289/**
290 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
291 * @type: FC-4 type, such as FC_TYPE_FCP
292 * @prov: structure describing provider including ops vector.
293 */
294void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
295{
296	BUG_ON(type >= FC_FC4_PROV_SIZE);
297	mutex_lock(&fc_prov_mutex);
298	if (prov->recv)
299		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
300	else
301		RCU_INIT_POINTER(fc_active_prov[type], NULL);
302	mutex_unlock(&fc_prov_mutex);
303	synchronize_rcu();
304}
305EXPORT_SYMBOL(fc_fc4_deregister_provider);
306
307/**
308 * fc_fc4_add_lport() - add new local port to list and run notifiers.
309 * @lport:  The new local port.
310 */
311void fc_fc4_add_lport(struct fc_lport *lport)
312{
313	mutex_lock(&fc_prov_mutex);
314	list_add_tail(&lport->lport_list, &fc_local_ports);
315	blocking_notifier_call_chain(&fc_lport_notifier_head,
316				     FC_LPORT_EV_ADD, lport);
317	mutex_unlock(&fc_prov_mutex);
318}
319
320/**
321 * fc_fc4_del_lport() - remove local port from list and run notifiers.
322 * @lport:  The new local port.
323 */
324void fc_fc4_del_lport(struct fc_lport *lport)
325{
326	mutex_lock(&fc_prov_mutex);
327	list_del(&lport->lport_list);
328	blocking_notifier_call_chain(&fc_lport_notifier_head,
329				     FC_LPORT_EV_DEL, lport);
330	mutex_unlock(&fc_prov_mutex);
331}
332