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 25 #include <scsi/libfc.h> 26 #include <scsi/fc_encode.h> 27 28 #include "fc_libfc.h" 29 30 MODULE_AUTHOR("Open-FCoE.org"); 31 MODULE_DESCRIPTION("libfc"); 32 MODULE_LICENSE("GPL v2"); 33 34 unsigned int fc_debug_logging; 35 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR); 36 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels"); 37 38 DEFINE_MUTEX(fc_prov_mutex); 39 static LIST_HEAD(fc_local_ports); 40 struct blocking_notifier_head fc_lport_notifier_head = 41 BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head); 42 EXPORT_SYMBOL(fc_lport_notifier_head); 43 44 /* 45 * Providers which primarily send requests and PRLIs. 46 */ 47 struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = { 48 [0] = &fc_rport_t0_prov, 49 [FC_TYPE_FCP] = &fc_rport_fcp_init, 50 }; 51 52 /* 53 * Providers which receive requests. 54 */ 55 struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = { 56 [FC_TYPE_ELS] = &fc_lport_els_prov, 57 }; 58 59 /** 60 * libfc_init() - Initialize libfc.ko 61 */ 62 static int __init libfc_init(void) 63 { 64 int rc = 0; 65 66 rc = fc_setup_fcp(); 67 if (rc) 68 return rc; 69 70 rc = fc_setup_exch_mgr(); 71 if (rc) 72 goto destroy_pkt_cache; 73 74 rc = fc_setup_rport(); 75 if (rc) 76 goto destroy_em; 77 78 return rc; 79 destroy_em: 80 fc_destroy_exch_mgr(); 81 destroy_pkt_cache: 82 fc_destroy_fcp(); 83 return rc; 84 } 85 module_init(libfc_init); 86 87 /** 88 * libfc_exit() - Tear down libfc.ko 89 */ 90 static void __exit libfc_exit(void) 91 { 92 fc_destroy_fcp(); 93 fc_destroy_exch_mgr(); 94 fc_destroy_rport(); 95 } 96 module_exit(libfc_exit); 97 98 /** 99 * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer 100 * into a scatter-gather list (SG list). 101 * 102 * @buf: pointer to the data buffer. 103 * @len: the byte-length of the data buffer. 104 * @sg: pointer to the pointer of the SG list. 105 * @nents: pointer to the remaining number of entries in the SG list. 106 * @offset: pointer to the current offset in the SG list. 107 * @km_type: dedicated page table slot type for kmap_atomic. 108 * @crc: pointer to the 32-bit crc value. 109 * If crc is NULL, CRC is not calculated. 110 */ 111 u32 fc_copy_buffer_to_sglist(void *buf, size_t len, 112 struct scatterlist *sg, 113 u32 *nents, size_t *offset, 114 enum km_type km_type, 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 km_type); 146 if (crc) 147 *crc = crc32(*crc, buf, sg_bytes); 148 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes); 149 kunmap_atomic(page_addr, km_type); 150 buf += sg_bytes; 151 *offset += sg_bytes; 152 remaining -= sg_bytes; 153 copy_len += sg_bytes; 154 } 155 return copy_len; 156 } 157 158 /** 159 * fc_fill_hdr() - fill FC header fields based on request 160 * @fp: reply frame containing header to be filled in 161 * @in_fp: request frame containing header to use in filling in reply 162 * @r_ctl: R_CTL value for header 163 * @f_ctl: F_CTL value for header, with 0 pad 164 * @seq_cnt: sequence count for the header, ignored if frame has a sequence 165 * @parm_offset: parameter / offset value 166 */ 167 void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp, 168 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset) 169 { 170 struct fc_frame_header *fh; 171 struct fc_frame_header *in_fh; 172 struct fc_seq *sp; 173 u32 fill; 174 175 fh = __fc_frame_header_get(fp); 176 in_fh = __fc_frame_header_get(in_fp); 177 178 if (f_ctl & FC_FC_END_SEQ) { 179 fill = -fr_len(fp) & 3; 180 if (fill) { 181 /* TODO, this may be a problem with fragmented skb */ 182 memset(skb_put(fp_skb(fp), fill), 0, fill); 183 f_ctl |= fill; 184 } 185 fr_eof(fp) = FC_EOF_T; 186 } else { 187 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */ 188 fr_eof(fp) = FC_EOF_N; 189 } 190 191 fh->fh_r_ctl = r_ctl; 192 memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id)); 193 memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id)); 194 fh->fh_type = in_fh->fh_type; 195 hton24(fh->fh_f_ctl, f_ctl); 196 fh->fh_ox_id = in_fh->fh_ox_id; 197 fh->fh_rx_id = in_fh->fh_rx_id; 198 fh->fh_cs_ctl = 0; 199 fh->fh_df_ctl = 0; 200 fh->fh_parm_offset = htonl(parm_offset); 201 202 sp = fr_seq(in_fp); 203 if (sp) { 204 fr_seq(fp) = sp; 205 fh->fh_seq_id = sp->id; 206 seq_cnt = sp->cnt; 207 } else { 208 fh->fh_seq_id = 0; 209 } 210 fh->fh_seq_cnt = ntohs(seq_cnt); 211 fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3; 212 fr_encaps(fp) = fr_encaps(in_fp); 213 } 214 EXPORT_SYMBOL(fc_fill_hdr); 215 216 /** 217 * fc_fill_reply_hdr() - fill FC reply header fields based on request 218 * @fp: reply frame containing header to be filled in 219 * @in_fp: request frame containing header to use in filling in reply 220 * @r_ctl: R_CTL value for reply 221 * @parm_offset: parameter / offset value 222 */ 223 void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp, 224 enum fc_rctl r_ctl, u32 parm_offset) 225 { 226 struct fc_seq *sp; 227 228 sp = fr_seq(in_fp); 229 if (sp) 230 fr_seq(fp) = fr_dev(in_fp)->tt.seq_start_next(sp); 231 fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset); 232 } 233 EXPORT_SYMBOL(fc_fill_reply_hdr); 234 235 /** 236 * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport 237 * if there is service provider (target provider) registered with libfc 238 * for specified "fc_ft_type" 239 * @lport: Local port which service_params needs to be modified 240 * @type: FC-4 type, such as FC_TYPE_FCP 241 */ 242 void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type) 243 { 244 struct fc4_prov *prov_entry; 245 BUG_ON(type >= FC_FC4_PROV_SIZE); 246 BUG_ON(!lport); 247 prov_entry = fc_passive_prov[type]; 248 if (type == FC_TYPE_FCP) { 249 if (prov_entry && prov_entry->recv) 250 lport->service_params |= FCP_SPPF_TARG_FCN; 251 } 252 } 253 254 void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg) 255 { 256 struct fc_lport *lport; 257 258 mutex_lock(&fc_prov_mutex); 259 list_for_each_entry(lport, &fc_local_ports, lport_list) 260 notify(lport, arg); 261 mutex_unlock(&fc_prov_mutex); 262 } 263 EXPORT_SYMBOL(fc_lport_iterate); 264 265 /** 266 * fc_fc4_register_provider() - register FC-4 upper-level provider. 267 * @type: FC-4 type, such as FC_TYPE_FCP 268 * @prov: structure describing provider including ops vector. 269 * 270 * Returns 0 on success, negative error otherwise. 271 */ 272 int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov) 273 { 274 struct fc4_prov **prov_entry; 275 int ret = 0; 276 277 if (type >= FC_FC4_PROV_SIZE) 278 return -EINVAL; 279 mutex_lock(&fc_prov_mutex); 280 prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type; 281 if (*prov_entry) 282 ret = -EBUSY; 283 else 284 *prov_entry = prov; 285 mutex_unlock(&fc_prov_mutex); 286 return ret; 287 } 288 EXPORT_SYMBOL(fc_fc4_register_provider); 289 290 /** 291 * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider. 292 * @type: FC-4 type, such as FC_TYPE_FCP 293 * @prov: structure describing provider including ops vector. 294 */ 295 void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov) 296 { 297 BUG_ON(type >= FC_FC4_PROV_SIZE); 298 mutex_lock(&fc_prov_mutex); 299 if (prov->recv) 300 rcu_assign_pointer(fc_passive_prov[type], NULL); 301 else 302 rcu_assign_pointer(fc_active_prov[type], NULL); 303 mutex_unlock(&fc_prov_mutex); 304 synchronize_rcu(); 305 } 306 EXPORT_SYMBOL(fc_fc4_deregister_provider); 307 308 /** 309 * fc_fc4_add_lport() - add new local port to list and run notifiers. 310 * @lport: The new local port. 311 */ 312 void fc_fc4_add_lport(struct fc_lport *lport) 313 { 314 mutex_lock(&fc_prov_mutex); 315 list_add_tail(&lport->lport_list, &fc_local_ports); 316 blocking_notifier_call_chain(&fc_lport_notifier_head, 317 FC_LPORT_EV_ADD, lport); 318 mutex_unlock(&fc_prov_mutex); 319 } 320 321 /** 322 * fc_fc4_del_lport() - remove local port from list and run notifiers. 323 * @lport: The new local port. 324 */ 325 void fc_fc4_del_lport(struct fc_lport *lport) 326 { 327 mutex_lock(&fc_prov_mutex); 328 list_del(&lport->lport_list); 329 blocking_notifier_call_chain(&fc_lport_notifier_head, 330 FC_LPORT_EV_DEL, lport); 331 mutex_unlock(&fc_prov_mutex); 332 } 333