1 /* 2 * Copyright (c) 2010 Cisco Systems, Inc. 3 * 4 * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c 5 * 6 * Copyright (c) 2007 Intel Corporation. All rights reserved. 7 * Copyright (c) 2008 Red Hat, Inc. All rights reserved. 8 * Copyright (c) 2008 Mike Christie 9 * Copyright (c) 2009 Rising Tide, Inc. 10 * Copyright (c) 2009 Linux-iSCSI.org 11 * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org> 12 * 13 * This program is free software; you can redistribute it and/or modify it 14 * under the terms and conditions of the GNU General Public License, 15 * version 2, as published by the Free Software Foundation. 16 * 17 * This program is distributed in the hope it will be useful, but WITHOUT 18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 20 * more details. 21 * 22 * You should have received a copy of the GNU General Public License along with 23 * this program; if not, write to the Free Software Foundation, Inc., 24 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 25 */ 26 27 /* XXX TBD some includes may be extraneous */ 28 29 #include <linux/module.h> 30 #include <linux/moduleparam.h> 31 #include <linux/utsname.h> 32 #include <linux/init.h> 33 #include <linux/slab.h> 34 #include <linux/kthread.h> 35 #include <linux/types.h> 36 #include <linux/string.h> 37 #include <linux/configfs.h> 38 #include <linux/ctype.h> 39 #include <linux/hash.h> 40 #include <linux/ratelimit.h> 41 #include <asm/unaligned.h> 42 #include <scsi/libfc.h> 43 #include <scsi/fc_encode.h> 44 45 #include <target/target_core_base.h> 46 #include <target/target_core_fabric.h> 47 #include <target/configfs_macros.h> 48 49 #include "tcm_fc.h" 50 51 /* 52 * Deliver read data back to initiator. 53 * XXX TBD handle resource problems later. 54 */ 55 int ft_queue_data_in(struct se_cmd *se_cmd) 56 { 57 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 58 struct fc_frame *fp = NULL; 59 struct fc_exch *ep; 60 struct fc_lport *lport; 61 struct scatterlist *sg = NULL; 62 size_t remaining; 63 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 64 u32 mem_off = 0; 65 u32 fh_off = 0; 66 u32 frame_off = 0; 67 size_t frame_len = 0; 68 size_t mem_len = 0; 69 size_t tlen; 70 size_t off_in_page; 71 struct page *page = NULL; 72 int use_sg; 73 int error; 74 void *page_addr; 75 void *from; 76 void *to = NULL; 77 78 if (cmd->aborted) 79 return 0; 80 81 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) 82 goto queue_status; 83 84 ep = fc_seq_exch(cmd->seq); 85 lport = ep->lp; 86 cmd->seq = lport->tt.seq_start_next(cmd->seq); 87 88 remaining = se_cmd->data_length; 89 90 /* 91 * Setup to use first mem list entry, unless no data. 92 */ 93 BUG_ON(remaining && !se_cmd->t_data_sg); 94 if (remaining) { 95 sg = se_cmd->t_data_sg; 96 mem_len = sg->length; 97 mem_off = sg->offset; 98 page = sg_page(sg); 99 } 100 101 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 102 use_sg = !(remaining % 4); 103 104 while (remaining) { 105 struct fc_seq *seq = cmd->seq; 106 107 if (!seq) { 108 pr_debug("%s: Command aborted, xid 0x%x\n", 109 __func__, ep->xid); 110 break; 111 } 112 if (!mem_len) { 113 sg = sg_next(sg); 114 mem_len = min((size_t)sg->length, remaining); 115 mem_off = sg->offset; 116 page = sg_page(sg); 117 } 118 if (!frame_len) { 119 /* 120 * If lport's has capability of Large Send Offload LSO) 121 * , then allow 'frame_len' to be as big as 'lso_max' 122 * if indicated transfer length is >= lport->lso_max 123 */ 124 frame_len = (lport->seq_offload) ? lport->lso_max : 125 cmd->sess->max_frame; 126 frame_len = min(frame_len, remaining); 127 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 128 if (!fp) 129 return -ENOMEM; 130 to = fc_frame_payload_get(fp, 0); 131 fh_off = frame_off; 132 frame_off += frame_len; 133 /* 134 * Setup the frame's max payload which is used by base 135 * driver to indicate HW about max frame size, so that 136 * HW can do fragmentation appropriately based on 137 * "gso_max_size" of underline netdev. 138 */ 139 fr_max_payload(fp) = cmd->sess->max_frame; 140 } 141 tlen = min(mem_len, frame_len); 142 143 if (use_sg) { 144 off_in_page = mem_off; 145 BUG_ON(!page); 146 get_page(page); 147 skb_fill_page_desc(fp_skb(fp), 148 skb_shinfo(fp_skb(fp))->nr_frags, 149 page, off_in_page, tlen); 150 fr_len(fp) += tlen; 151 fp_skb(fp)->data_len += tlen; 152 fp_skb(fp)->truesize += 153 PAGE_SIZE << compound_order(page); 154 } else { 155 BUG_ON(!page); 156 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 157 page_addr = from; 158 from += mem_off & ~PAGE_MASK; 159 tlen = min(tlen, (size_t)(PAGE_SIZE - 160 (mem_off & ~PAGE_MASK))); 161 memcpy(to, from, tlen); 162 kunmap_atomic(page_addr); 163 to += tlen; 164 } 165 166 mem_off += tlen; 167 mem_len -= tlen; 168 frame_len -= tlen; 169 remaining -= tlen; 170 171 if (frame_len && 172 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 173 continue; 174 if (!remaining) 175 f_ctl |= FC_FC_END_SEQ; 176 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 177 FC_TYPE_FCP, f_ctl, fh_off); 178 error = lport->tt.seq_send(lport, seq, fp); 179 if (error) { 180 pr_info_ratelimited("%s: Failed to send frame %p, " 181 "xid <0x%x>, remaining %zu, " 182 "lso_max <0x%x>\n", 183 __func__, fp, ep->xid, 184 remaining, lport->lso_max); 185 /* 186 * Go ahead and set TASK_SET_FULL status ignoring the 187 * rest of the DataIN, and immediately attempt to 188 * send the response via ft_queue_status() in order 189 * to notify the initiator that it should reduce it's 190 * per LUN queue_depth. 191 */ 192 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 193 break; 194 } 195 } 196 queue_status: 197 return ft_queue_status(se_cmd); 198 } 199 200 static void ft_execute_work(struct work_struct *work) 201 { 202 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 203 204 target_execute_cmd(&cmd->se_cmd); 205 } 206 207 /* 208 * Receive write data frame. 209 */ 210 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 211 { 212 struct se_cmd *se_cmd = &cmd->se_cmd; 213 struct fc_seq *seq = cmd->seq; 214 struct fc_exch *ep; 215 struct fc_lport *lport; 216 struct fc_frame_header *fh; 217 struct scatterlist *sg = NULL; 218 u32 mem_off = 0; 219 u32 rel_off; 220 size_t frame_len; 221 size_t mem_len = 0; 222 size_t tlen; 223 struct page *page = NULL; 224 void *page_addr; 225 void *from; 226 void *to; 227 u32 f_ctl; 228 void *buf; 229 230 fh = fc_frame_header_get(fp); 231 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 232 goto drop; 233 234 f_ctl = ntoh24(fh->fh_f_ctl); 235 ep = fc_seq_exch(seq); 236 lport = ep->lp; 237 if (cmd->was_ddp_setup) { 238 BUG_ON(!ep); 239 BUG_ON(!lport); 240 /* 241 * Since DDP (Large Rx offload) was setup for this request, 242 * payload is expected to be copied directly to user buffers. 243 */ 244 buf = fc_frame_payload_get(fp, 1); 245 if (buf) 246 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 247 "cmd->sg_cnt 0x%x. DDP was setup" 248 " hence not expected to receive frame with " 249 "payload, Frame will be dropped if" 250 "'Sequence Initiative' bit in f_ctl is" 251 "not set\n", __func__, ep->xid, f_ctl, 252 se_cmd->t_data_sg, se_cmd->t_data_nents); 253 /* 254 * Invalidate HW DDP context if it was setup for respective 255 * command. Invalidation of HW DDP context is requited in both 256 * situation (success and error). 257 */ 258 ft_invl_hw_context(cmd); 259 260 /* 261 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 262 * write data frame is received successfully where payload is 263 * posted directly to user buffer and only the last frame's 264 * header is posted in receive queue. 265 * 266 * If "Sequence Initiative (TSI)" bit is not set, means error 267 * condition w.r.t. DDP, hence drop the packet and let explict 268 * ABORTS from other end of exchange timer trigger the recovery. 269 */ 270 if (f_ctl & FC_FC_SEQ_INIT) 271 goto last_frame; 272 else 273 goto drop; 274 } 275 276 rel_off = ntohl(fh->fh_parm_offset); 277 frame_len = fr_len(fp); 278 if (frame_len <= sizeof(*fh)) 279 goto drop; 280 frame_len -= sizeof(*fh); 281 from = fc_frame_payload_get(fp, 0); 282 if (rel_off >= se_cmd->data_length) 283 goto drop; 284 if (frame_len + rel_off > se_cmd->data_length) 285 frame_len = se_cmd->data_length - rel_off; 286 287 /* 288 * Setup to use first mem list entry, unless no data. 289 */ 290 BUG_ON(frame_len && !se_cmd->t_data_sg); 291 if (frame_len) { 292 sg = se_cmd->t_data_sg; 293 mem_len = sg->length; 294 mem_off = sg->offset; 295 page = sg_page(sg); 296 } 297 298 while (frame_len) { 299 if (!mem_len) { 300 sg = sg_next(sg); 301 mem_len = sg->length; 302 mem_off = sg->offset; 303 page = sg_page(sg); 304 } 305 if (rel_off >= mem_len) { 306 rel_off -= mem_len; 307 mem_len = 0; 308 continue; 309 } 310 mem_off += rel_off; 311 mem_len -= rel_off; 312 rel_off = 0; 313 314 tlen = min(mem_len, frame_len); 315 316 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 317 page_addr = to; 318 to += mem_off & ~PAGE_MASK; 319 tlen = min(tlen, (size_t)(PAGE_SIZE - 320 (mem_off & ~PAGE_MASK))); 321 memcpy(to, from, tlen); 322 kunmap_atomic(page_addr); 323 324 from += tlen; 325 frame_len -= tlen; 326 mem_off += tlen; 327 mem_len -= tlen; 328 cmd->write_data_len += tlen; 329 } 330 last_frame: 331 if (cmd->write_data_len == se_cmd->data_length) { 332 INIT_WORK(&cmd->work, ft_execute_work); 333 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 334 } 335 drop: 336 fc_frame_free(fp); 337 } 338 339 /* 340 * Handle and cleanup any HW specific resources if 341 * received ABORTS, errors, timeouts. 342 */ 343 void ft_invl_hw_context(struct ft_cmd *cmd) 344 { 345 struct fc_seq *seq; 346 struct fc_exch *ep = NULL; 347 struct fc_lport *lport = NULL; 348 349 BUG_ON(!cmd); 350 seq = cmd->seq; 351 352 /* Cleanup the DDP context in HW if DDP was setup */ 353 if (cmd->was_ddp_setup && seq) { 354 ep = fc_seq_exch(seq); 355 if (ep) { 356 lport = ep->lp; 357 if (lport && (ep->xid <= lport->lro_xid)) { 358 /* 359 * "ddp_done" trigger invalidation of HW 360 * specific DDP context 361 */ 362 cmd->write_data_len = lport->tt.ddp_done(lport, 363 ep->xid); 364 365 /* 366 * Resetting same variable to indicate HW's 367 * DDP context has been invalidated to avoid 368 * re_invalidation of same context (context is 369 * identified using ep->xid) 370 */ 371 cmd->was_ddp_setup = 0; 372 } 373 } 374 } 375 } 376