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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2009 Intel Corporation. All rights reserved.
4 *
5 * Maintained at www.Open-FCoE.org
6 */
7
8#include <linux/kernel.h>
9#include <linux/types.h>
10#include <linux/scatterlist.h>
11#include <linux/crc32.h>
12#include <linux/module.h>
13
14#include <scsi/libfc.h>
15
16#include "fc_encode.h"
17#include "fc_libfc.h"
18
19MODULE_AUTHOR("Open-FCoE.org");
20MODULE_DESCRIPTION("libfc");
21MODULE_LICENSE("GPL v2");
22
23unsigned int fc_debug_logging;
24module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
25MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
26
27DEFINE_MUTEX(fc_prov_mutex);
28static LIST_HEAD(fc_local_ports);
29struct blocking_notifier_head fc_lport_notifier_head =
30 BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
31EXPORT_SYMBOL(fc_lport_notifier_head);
32
33/*
34 * Providers which primarily send requests and PRLIs.
35 */
36struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
37 [0] = &fc_rport_t0_prov,
38 [FC_TYPE_FCP] = &fc_rport_fcp_init,
39};
40
41/*
42 * Providers which receive requests.
43 */
44struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
45 [FC_TYPE_ELS] = &fc_lport_els_prov,
46};
47
48/**
49 * libfc_init() - Initialize libfc.ko
50 */
51static int __init libfc_init(void)
52{
53 int rc = 0;
54
55 rc = fc_setup_fcp();
56 if (rc)
57 return rc;
58
59 rc = fc_setup_exch_mgr();
60 if (rc)
61 goto destroy_pkt_cache;
62
63 rc = fc_setup_rport();
64 if (rc)
65 goto destroy_em;
66
67 return rc;
68destroy_em:
69 fc_destroy_exch_mgr();
70destroy_pkt_cache:
71 fc_destroy_fcp();
72 return rc;
73}
74module_init(libfc_init);
75
76/**
77 * libfc_exit() - Tear down libfc.ko
78 */
79static void __exit libfc_exit(void)
80{
81 fc_destroy_fcp();
82 fc_destroy_exch_mgr();
83 fc_destroy_rport();
84}
85module_exit(libfc_exit);
86
87/**
88 * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
89 * into a scatter-gather list (SG list).
90 *
91 * @buf: pointer to the data buffer.
92 * @len: the byte-length of the data buffer.
93 * @sg: pointer to the pointer of the SG list.
94 * @nents: pointer to the remaining number of entries in the SG list.
95 * @offset: pointer to the current offset in the SG list.
96 * @crc: pointer to the 32-bit crc value.
97 * If crc is NULL, CRC is not calculated.
98 */
99u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
100 struct scatterlist *sg,
101 u32 *nents, size_t *offset,
102 u32 *crc)
103{
104 size_t remaining = len;
105 u32 copy_len = 0;
106
107 while (remaining > 0 && sg) {
108 size_t off, sg_bytes;
109 void *page_addr;
110
111 if (*offset >= sg->length) {
112 /*
113 * Check for end and drop resources
114 * from the last iteration.
115 */
116 if (!(*nents))
117 break;
118 --(*nents);
119 *offset -= sg->length;
120 sg = sg_next(sg);
121 continue;
122 }
123 sg_bytes = min(remaining, sg->length - *offset);
124
125 /*
126 * The scatterlist item may be bigger than PAGE_SIZE,
127 * but we are limited to mapping PAGE_SIZE at a time.
128 */
129 off = *offset + sg->offset;
130 sg_bytes = min(sg_bytes,
131 (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
132 page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
133 if (crc)
134 *crc = crc32(*crc, buf, sg_bytes);
135 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
136 kunmap_atomic(page_addr);
137 buf += sg_bytes;
138 *offset += sg_bytes;
139 remaining -= sg_bytes;
140 copy_len += sg_bytes;
141 }
142 return copy_len;
143}
144
145/**
146 * fc_fill_hdr() - fill FC header fields based on request
147 * @fp: reply frame containing header to be filled in
148 * @in_fp: request frame containing header to use in filling in reply
149 * @r_ctl: R_CTL value for header
150 * @f_ctl: F_CTL value for header, with 0 pad
151 * @seq_cnt: sequence count for the header, ignored if frame has a sequence
152 * @parm_offset: parameter / offset value
153 */
154void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
155 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
156{
157 struct fc_frame_header *fh;
158 struct fc_frame_header *in_fh;
159 struct fc_seq *sp;
160 u32 fill;
161
162 fh = __fc_frame_header_get(fp);
163 in_fh = __fc_frame_header_get(in_fp);
164
165 if (f_ctl & FC_FC_END_SEQ) {
166 fill = -fr_len(fp) & 3;
167 if (fill) {
168 /* TODO, this may be a problem with fragmented skb */
169 skb_put_zero(fp_skb(fp), fill);
170 f_ctl |= fill;
171 }
172 fr_eof(fp) = FC_EOF_T;
173 } else {
174 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
175 fr_eof(fp) = FC_EOF_N;
176 }
177
178 fh->fh_r_ctl = r_ctl;
179 memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
180 memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
181 fh->fh_type = in_fh->fh_type;
182 hton24(fh->fh_f_ctl, f_ctl);
183 fh->fh_ox_id = in_fh->fh_ox_id;
184 fh->fh_rx_id = in_fh->fh_rx_id;
185 fh->fh_cs_ctl = 0;
186 fh->fh_df_ctl = 0;
187 fh->fh_parm_offset = htonl(parm_offset);
188
189 sp = fr_seq(in_fp);
190 if (sp) {
191 fr_seq(fp) = sp;
192 fh->fh_seq_id = sp->id;
193 seq_cnt = sp->cnt;
194 } else {
195 fh->fh_seq_id = 0;
196 }
197 fh->fh_seq_cnt = ntohs(seq_cnt);
198 fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
199 fr_encaps(fp) = fr_encaps(in_fp);
200}
201EXPORT_SYMBOL(fc_fill_hdr);
202
203/**
204 * fc_fill_reply_hdr() - fill FC reply header fields based on request
205 * @fp: reply frame containing header to be filled in
206 * @in_fp: request frame containing header to use in filling in reply
207 * @r_ctl: R_CTL value for reply
208 * @parm_offset: parameter / offset value
209 */
210void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
211 enum fc_rctl r_ctl, u32 parm_offset)
212{
213 struct fc_seq *sp;
214
215 sp = fr_seq(in_fp);
216 if (sp)
217 fr_seq(fp) = fc_seq_start_next(sp);
218 fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
219}
220EXPORT_SYMBOL(fc_fill_reply_hdr);
221
222/**
223 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
224 * if there is service provider (target provider) registered with libfc
225 * for specified "fc_ft_type"
226 * @lport: Local port which service_params needs to be modified
227 * @type: FC-4 type, such as FC_TYPE_FCP
228 */
229void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
230{
231 struct fc4_prov *prov_entry;
232 BUG_ON(type >= FC_FC4_PROV_SIZE);
233 BUG_ON(!lport);
234 prov_entry = fc_passive_prov[type];
235 if (type == FC_TYPE_FCP) {
236 if (prov_entry && prov_entry->recv)
237 lport->service_params |= FCP_SPPF_TARG_FCN;
238 }
239}
240
241void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg)
242{
243 struct fc_lport *lport;
244
245 mutex_lock(&fc_prov_mutex);
246 list_for_each_entry(lport, &fc_local_ports, lport_list)
247 notify(lport, arg);
248 mutex_unlock(&fc_prov_mutex);
249}
250EXPORT_SYMBOL(fc_lport_iterate);
251
252/**
253 * fc_fc4_register_provider() - register FC-4 upper-level provider.
254 * @type: FC-4 type, such as FC_TYPE_FCP
255 * @prov: structure describing provider including ops vector.
256 *
257 * Returns 0 on success, negative error otherwise.
258 */
259int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
260{
261 struct fc4_prov **prov_entry;
262 int ret = 0;
263
264 if (type >= FC_FC4_PROV_SIZE)
265 return -EINVAL;
266 mutex_lock(&fc_prov_mutex);
267 prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
268 if (*prov_entry)
269 ret = -EBUSY;
270 else
271 *prov_entry = prov;
272 mutex_unlock(&fc_prov_mutex);
273 return ret;
274}
275EXPORT_SYMBOL(fc_fc4_register_provider);
276
277/**
278 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
279 * @type: FC-4 type, such as FC_TYPE_FCP
280 * @prov: structure describing provider including ops vector.
281 */
282void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
283{
284 BUG_ON(type >= FC_FC4_PROV_SIZE);
285 mutex_lock(&fc_prov_mutex);
286 if (prov->recv)
287 RCU_INIT_POINTER(fc_passive_prov[type], NULL);
288 else
289 RCU_INIT_POINTER(fc_active_prov[type], NULL);
290 mutex_unlock(&fc_prov_mutex);
291 synchronize_rcu();
292}
293EXPORT_SYMBOL(fc_fc4_deregister_provider);
294
295/**
296 * fc_fc4_add_lport() - add new local port to list and run notifiers.
297 * @lport: The new local port.
298 */
299void fc_fc4_add_lport(struct fc_lport *lport)
300{
301 mutex_lock(&fc_prov_mutex);
302 list_add_tail(&lport->lport_list, &fc_local_ports);
303 blocking_notifier_call_chain(&fc_lport_notifier_head,
304 FC_LPORT_EV_ADD, lport);
305 mutex_unlock(&fc_prov_mutex);
306}
307
308/**
309 * fc_fc4_del_lport() - remove local port from list and run notifiers.
310 * @lport: The new local port.
311 */
312void fc_fc4_del_lport(struct fc_lport *lport)
313{
314 mutex_lock(&fc_prov_mutex);
315 list_del(&lport->lport_list);
316 blocking_notifier_call_chain(&fc_lport_notifier_head,
317 FC_LPORT_EV_DEL, lport);
318 mutex_unlock(&fc_prov_mutex);
319}