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 */ 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 */ 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 * @km_type: dedicated page table slot type for kmap_atomic. 109 * @crc: pointer to the 32-bit crc value. 110 * If crc is NULL, CRC is not calculated. 111 */ 112 u32 fc_copy_buffer_to_sglist(void *buf, size_t len, 113 struct scatterlist *sg, 114 u32 *nents, size_t *offset, 115 enum km_type km_type, u32 *crc) 116 { 117 size_t remaining = len; 118 u32 copy_len = 0; 119 120 while (remaining > 0 && sg) { 121 size_t off, sg_bytes; 122 void *page_addr; 123 124 if (*offset >= sg->length) { 125 /* 126 * Check for end and drop resources 127 * from the last iteration. 128 */ 129 if (!(*nents)) 130 break; 131 --(*nents); 132 *offset -= sg->length; 133 sg = sg_next(sg); 134 continue; 135 } 136 sg_bytes = min(remaining, sg->length - *offset); 137 138 /* 139 * The scatterlist item may be bigger than PAGE_SIZE, 140 * but we are limited to mapping PAGE_SIZE at a time. 141 */ 142 off = *offset + sg->offset; 143 sg_bytes = min(sg_bytes, 144 (size_t)(PAGE_SIZE - (off & ~PAGE_MASK))); 145 page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT), 146 km_type); 147 if (crc) 148 *crc = crc32(*crc, buf, sg_bytes); 149 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes); 150 kunmap_atomic(page_addr, km_type); 151 buf += sg_bytes; 152 *offset += sg_bytes; 153 remaining -= sg_bytes; 154 copy_len += sg_bytes; 155 } 156 return copy_len; 157 } 158 159 /** 160 * fc_fill_hdr() - fill FC header fields based on request 161 * @fp: reply frame containing header to be filled in 162 * @in_fp: request frame containing header to use in filling in reply 163 * @r_ctl: R_CTL value for header 164 * @f_ctl: F_CTL value for header, with 0 pad 165 * @seq_cnt: sequence count for the header, ignored if frame has a sequence 166 * @parm_offset: parameter / offset value 167 */ 168 void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp, 169 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset) 170 { 171 struct fc_frame_header *fh; 172 struct fc_frame_header *in_fh; 173 struct fc_seq *sp; 174 u32 fill; 175 176 fh = __fc_frame_header_get(fp); 177 in_fh = __fc_frame_header_get(in_fp); 178 179 if (f_ctl & FC_FC_END_SEQ) { 180 fill = -fr_len(fp) & 3; 181 if (fill) { 182 /* TODO, this may be a problem with fragmented skb */ 183 memset(skb_put(fp_skb(fp), fill), 0, fill); 184 f_ctl |= fill; 185 } 186 fr_eof(fp) = FC_EOF_T; 187 } else { 188 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */ 189 fr_eof(fp) = FC_EOF_N; 190 } 191 192 fh->fh_r_ctl = r_ctl; 193 memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id)); 194 memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id)); 195 fh->fh_type = in_fh->fh_type; 196 hton24(fh->fh_f_ctl, f_ctl); 197 fh->fh_ox_id = in_fh->fh_ox_id; 198 fh->fh_rx_id = in_fh->fh_rx_id; 199 fh->fh_cs_ctl = 0; 200 fh->fh_df_ctl = 0; 201 fh->fh_parm_offset = htonl(parm_offset); 202 203 sp = fr_seq(in_fp); 204 if (sp) { 205 fr_seq(fp) = sp; 206 fh->fh_seq_id = sp->id; 207 seq_cnt = sp->cnt; 208 } else { 209 fh->fh_seq_id = 0; 210 } 211 fh->fh_seq_cnt = ntohs(seq_cnt); 212 fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3; 213 fr_encaps(fp) = fr_encaps(in_fp); 214 } 215 EXPORT_SYMBOL(fc_fill_hdr); 216 217 /** 218 * fc_fill_reply_hdr() - fill FC reply header fields based on request 219 * @fp: reply frame containing header to be filled in 220 * @in_fp: request frame containing header to use in filling in reply 221 * @r_ctl: R_CTL value for reply 222 * @parm_offset: parameter / offset value 223 */ 224 void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp, 225 enum fc_rctl r_ctl, u32 parm_offset) 226 { 227 struct fc_seq *sp; 228 229 sp = fr_seq(in_fp); 230 if (sp) 231 fr_seq(fp) = fr_dev(in_fp)->tt.seq_start_next(sp); 232 fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset); 233 } 234 EXPORT_SYMBOL(fc_fill_reply_hdr); 235 236 /** 237 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport 238 * if there is service provider (target provider) registered with libfc 239 * for specified "fc_ft_type" 240 * @lport: Local port which service_params needs to be modified 241 * @type: FC-4 type, such as FC_TYPE_FCP 242 */ 243 void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type) 244 { 245 struct fc4_prov *prov_entry; 246 BUG_ON(type >= FC_FC4_PROV_SIZE); 247 BUG_ON(!lport); 248 prov_entry = fc_passive_prov[type]; 249 if (type == FC_TYPE_FCP) { 250 if (prov_entry && prov_entry->recv) 251 lport->service_params |= FCP_SPPF_TARG_FCN; 252 } 253 } 254 255 void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg) 256 { 257 struct fc_lport *lport; 258 259 mutex_lock(&fc_prov_mutex); 260 list_for_each_entry(lport, &fc_local_ports, lport_list) 261 notify(lport, arg); 262 mutex_unlock(&fc_prov_mutex); 263 } 264 EXPORT_SYMBOL(fc_lport_iterate); 265 266 /** 267 * fc_fc4_register_provider() - register FC-4 upper-level provider. 268 * @type: FC-4 type, such as FC_TYPE_FCP 269 * @prov: structure describing provider including ops vector. 270 * 271 * Returns 0 on success, negative error otherwise. 272 */ 273 int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov) 274 { 275 struct fc4_prov **prov_entry; 276 int ret = 0; 277 278 if (type >= FC_FC4_PROV_SIZE) 279 return -EINVAL; 280 mutex_lock(&fc_prov_mutex); 281 prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type; 282 if (*prov_entry) 283 ret = -EBUSY; 284 else 285 *prov_entry = prov; 286 mutex_unlock(&fc_prov_mutex); 287 return ret; 288 } 289 EXPORT_SYMBOL(fc_fc4_register_provider); 290 291 /** 292 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider. 293 * @type: FC-4 type, such as FC_TYPE_FCP 294 * @prov: structure describing provider including ops vector. 295 */ 296 void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov) 297 { 298 BUG_ON(type >= FC_FC4_PROV_SIZE); 299 mutex_lock(&fc_prov_mutex); 300 if (prov->recv) 301 rcu_assign_pointer(fc_passive_prov[type], NULL); 302 else 303 rcu_assign_pointer(fc_active_prov[type], NULL); 304 mutex_unlock(&fc_prov_mutex); 305 synchronize_rcu(); 306 } 307 EXPORT_SYMBOL(fc_fc4_deregister_provider); 308 309 /** 310 * fc_fc4_add_lport() - add new local port to list and run notifiers. 311 * @lport: The new local port. 312 */ 313 void fc_fc4_add_lport(struct fc_lport *lport) 314 { 315 mutex_lock(&fc_prov_mutex); 316 list_add_tail(&lport->lport_list, &fc_local_ports); 317 blocking_notifier_call_chain(&fc_lport_notifier_head, 318 FC_LPORT_EV_ADD, lport); 319 mutex_unlock(&fc_prov_mutex); 320 } 321 322 /** 323 * fc_fc4_del_lport() - remove local port from list and run notifiers. 324 * @lport: The new local port. 325 */ 326 void fc_fc4_del_lport(struct fc_lport *lport) 327 { 328 mutex_lock(&fc_prov_mutex); 329 list_del(&lport->lport_list); 330 blocking_notifier_call_chain(&fc_lport_notifier_head, 331 FC_LPORT_EV_DEL, lport); 332 mutex_unlock(&fc_prov_mutex); 333 } 334