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
31 MODULE_AUTHOR("Open-FCoE.org");
32 MODULE_DESCRIPTION("libfc");
33 MODULE_LICENSE("GPL v2");
34
35 unsigned int fc_debug_logging;
36 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
37 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
38
39 DEFINE_MUTEX(fc_prov_mutex);
40 static LIST_HEAD(fc_local_ports);
41 struct blocking_notifier_head fc_lport_notifier_head =
42 BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
43 EXPORT_SYMBOL(fc_lport_notifier_head);
44
45 /*
46 * Providers which primarily send requests and PRLIs.
47 */
48 struct 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 */
56 struct 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 */
libfc_init(void)63 static 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;
80 destroy_em:
81 fc_destroy_exch_mgr();
82 destroy_pkt_cache:
83 fc_destroy_fcp();
84 return rc;
85 }
86 module_init(libfc_init);
87
88 /**
89 * libfc_exit() - Tear down libfc.ko
90 */
libfc_exit(void)91 static void __exit libfc_exit(void)
92 {
93 fc_destroy_fcp();
94 fc_destroy_exch_mgr();
95 fc_destroy_rport();
96 }
97 module_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 */
fc_copy_buffer_to_sglist(void * buf,size_t len,struct scatterlist * sg,u32 * nents,size_t * offset,u32 * crc)111 u32 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 */
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)166 void 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 skb_put_zero(fp_skb(fp), 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 }
213 EXPORT_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 */
fc_fill_reply_hdr(struct fc_frame * fp,const struct fc_frame * in_fp,enum fc_rctl r_ctl,u32 parm_offset)222 void 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) = fc_seq_start_next(sp);
230 fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
231 }
232 EXPORT_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 */
fc_fc4_conf_lport_params(struct fc_lport * lport,enum fc_fh_type type)241 void 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
fc_lport_iterate(void (* notify)(struct fc_lport *,void *),void * arg)253 void 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 }
262 EXPORT_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 */
fc_fc4_register_provider(enum fc_fh_type type,struct fc4_prov * prov)271 int 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 }
287 EXPORT_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 */
fc_fc4_deregister_provider(enum fc_fh_type type,struct fc4_prov * prov)294 void 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 }
305 EXPORT_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 */
fc_fc4_add_lport(struct fc_lport * lport)311 void 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 */
fc_fc4_del_lport(struct fc_lport * lport)324 void 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
