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 48 #include "tcm_fc.h" 49 50 /* 51 * Deliver read data back to initiator. 52 * XXX TBD handle resource problems later. 53 */ 54 int ft_queue_data_in(struct se_cmd *se_cmd) 55 { 56 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 57 struct fc_frame *fp = NULL; 58 struct fc_exch *ep; 59 struct fc_lport *lport; 60 struct scatterlist *sg = NULL; 61 size_t remaining; 62 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 63 u32 mem_off = 0; 64 u32 fh_off = 0; 65 u32 frame_off = 0; 66 size_t frame_len = 0; 67 size_t mem_len = 0; 68 size_t tlen; 69 size_t off_in_page; 70 struct page *page = NULL; 71 int use_sg; 72 int error; 73 void *page_addr; 74 void *from; 75 void *to = NULL; 76 77 if (cmd->aborted) 78 return 0; 79 80 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) 81 goto queue_status; 82 83 ep = fc_seq_exch(cmd->seq); 84 lport = ep->lp; 85 cmd->seq = lport->tt.seq_start_next(cmd->seq); 86 87 remaining = se_cmd->data_length; 88 89 /* 90 * Setup to use first mem list entry, unless no data. 91 */ 92 BUG_ON(remaining && !se_cmd->t_data_sg); 93 if (remaining) { 94 sg = se_cmd->t_data_sg; 95 mem_len = sg->length; 96 mem_off = sg->offset; 97 page = sg_page(sg); 98 } 99 100 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 101 use_sg = !(remaining % 4); 102 103 while (remaining) { 104 struct fc_seq *seq = cmd->seq; 105 106 if (!seq) { 107 pr_debug("%s: Command aborted, xid 0x%x\n", 108 __func__, ep->xid); 109 break; 110 } 111 if (!mem_len) { 112 sg = sg_next(sg); 113 mem_len = min((size_t)sg->length, remaining); 114 mem_off = sg->offset; 115 page = sg_page(sg); 116 } 117 if (!frame_len) { 118 /* 119 * If lport's has capability of Large Send Offload LSO) 120 * , then allow 'frame_len' to be as big as 'lso_max' 121 * if indicated transfer length is >= lport->lso_max 122 */ 123 frame_len = (lport->seq_offload) ? lport->lso_max : 124 cmd->sess->max_frame; 125 frame_len = min(frame_len, remaining); 126 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 127 if (!fp) 128 return -ENOMEM; 129 to = fc_frame_payload_get(fp, 0); 130 fh_off = frame_off; 131 frame_off += frame_len; 132 /* 133 * Setup the frame's max payload which is used by base 134 * driver to indicate HW about max frame size, so that 135 * HW can do fragmentation appropriately based on 136 * "gso_max_size" of underline netdev. 137 */ 138 fr_max_payload(fp) = cmd->sess->max_frame; 139 } 140 tlen = min(mem_len, frame_len); 141 142 if (use_sg) { 143 off_in_page = mem_off; 144 BUG_ON(!page); 145 get_page(page); 146 skb_fill_page_desc(fp_skb(fp), 147 skb_shinfo(fp_skb(fp))->nr_frags, 148 page, off_in_page, tlen); 149 fr_len(fp) += tlen; 150 fp_skb(fp)->data_len += tlen; 151 fp_skb(fp)->truesize += 152 PAGE_SIZE << compound_order(page); 153 } else { 154 BUG_ON(!page); 155 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 156 page_addr = from; 157 from += offset_in_page(mem_off); 158 tlen = min(tlen, (size_t)(PAGE_SIZE - 159 offset_in_page(mem_off))); 160 memcpy(to, from, tlen); 161 kunmap_atomic(page_addr); 162 to += tlen; 163 } 164 165 mem_off += tlen; 166 mem_len -= tlen; 167 frame_len -= tlen; 168 remaining -= tlen; 169 170 if (frame_len && 171 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 172 continue; 173 if (!remaining) 174 f_ctl |= FC_FC_END_SEQ; 175 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 176 FC_TYPE_FCP, f_ctl, fh_off); 177 error = lport->tt.seq_send(lport, seq, fp); 178 if (error) { 179 pr_info_ratelimited("%s: Failed to send frame %p, " 180 "xid <0x%x>, remaining %zu, " 181 "lso_max <0x%x>\n", 182 __func__, fp, ep->xid, 183 remaining, lport->lso_max); 184 /* 185 * Go ahead and set TASK_SET_FULL status ignoring the 186 * rest of the DataIN, and immediately attempt to 187 * send the response via ft_queue_status() in order 188 * to notify the initiator that it should reduce it's 189 * per LUN queue_depth. 190 */ 191 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 192 break; 193 } 194 } 195 queue_status: 196 return ft_queue_status(se_cmd); 197 } 198 199 static void ft_execute_work(struct work_struct *work) 200 { 201 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 202 203 target_execute_cmd(&cmd->se_cmd); 204 } 205 206 /* 207 * Receive write data frame. 208 */ 209 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 210 { 211 struct se_cmd *se_cmd = &cmd->se_cmd; 212 struct fc_seq *seq = cmd->seq; 213 struct fc_exch *ep; 214 struct fc_lport *lport; 215 struct fc_frame_header *fh; 216 struct scatterlist *sg = NULL; 217 u32 mem_off = 0; 218 u32 rel_off; 219 size_t frame_len; 220 size_t mem_len = 0; 221 size_t tlen; 222 struct page *page = NULL; 223 void *page_addr; 224 void *from; 225 void *to; 226 u32 f_ctl; 227 void *buf; 228 229 fh = fc_frame_header_get(fp); 230 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 231 goto drop; 232 233 f_ctl = ntoh24(fh->fh_f_ctl); 234 ep = fc_seq_exch(seq); 235 lport = ep->lp; 236 if (cmd->was_ddp_setup) { 237 BUG_ON(!ep); 238 BUG_ON(!lport); 239 /* 240 * Since DDP (Large Rx offload) was setup for this request, 241 * payload is expected to be copied directly to user buffers. 242 */ 243 buf = fc_frame_payload_get(fp, 1); 244 if (buf) 245 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 246 "cmd->sg_cnt 0x%x. DDP was setup" 247 " hence not expected to receive frame with " 248 "payload, Frame will be dropped if" 249 "'Sequence Initiative' bit in f_ctl is" 250 "not set\n", __func__, ep->xid, f_ctl, 251 se_cmd->t_data_sg, se_cmd->t_data_nents); 252 /* 253 * Invalidate HW DDP context if it was setup for respective 254 * command. Invalidation of HW DDP context is requited in both 255 * situation (success and error). 256 */ 257 ft_invl_hw_context(cmd); 258 259 /* 260 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 261 * write data frame is received successfully where payload is 262 * posted directly to user buffer and only the last frame's 263 * header is posted in receive queue. 264 * 265 * If "Sequence Initiative (TSI)" bit is not set, means error 266 * condition w.r.t. DDP, hence drop the packet and let explict 267 * ABORTS from other end of exchange timer trigger the recovery. 268 */ 269 if (f_ctl & FC_FC_SEQ_INIT) 270 goto last_frame; 271 else 272 goto drop; 273 } 274 275 rel_off = ntohl(fh->fh_parm_offset); 276 frame_len = fr_len(fp); 277 if (frame_len <= sizeof(*fh)) 278 goto drop; 279 frame_len -= sizeof(*fh); 280 from = fc_frame_payload_get(fp, 0); 281 if (rel_off >= se_cmd->data_length) 282 goto drop; 283 if (frame_len + rel_off > se_cmd->data_length) 284 frame_len = se_cmd->data_length - rel_off; 285 286 /* 287 * Setup to use first mem list entry, unless no data. 288 */ 289 BUG_ON(frame_len && !se_cmd->t_data_sg); 290 if (frame_len) { 291 sg = se_cmd->t_data_sg; 292 mem_len = sg->length; 293 mem_off = sg->offset; 294 page = sg_page(sg); 295 } 296 297 while (frame_len) { 298 if (!mem_len) { 299 sg = sg_next(sg); 300 mem_len = sg->length; 301 mem_off = sg->offset; 302 page = sg_page(sg); 303 } 304 if (rel_off >= mem_len) { 305 rel_off -= mem_len; 306 mem_len = 0; 307 continue; 308 } 309 mem_off += rel_off; 310 mem_len -= rel_off; 311 rel_off = 0; 312 313 tlen = min(mem_len, frame_len); 314 315 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 316 page_addr = to; 317 to += offset_in_page(mem_off); 318 tlen = min(tlen, (size_t)(PAGE_SIZE - 319 offset_in_page(mem_off))); 320 memcpy(to, from, tlen); 321 kunmap_atomic(page_addr); 322 323 from += tlen; 324 frame_len -= tlen; 325 mem_off += tlen; 326 mem_len -= tlen; 327 cmd->write_data_len += tlen; 328 } 329 last_frame: 330 if (cmd->write_data_len == se_cmd->data_length) { 331 INIT_WORK(&cmd->work, ft_execute_work); 332 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 333 } 334 drop: 335 fc_frame_free(fp); 336 } 337 338 /* 339 * Handle and cleanup any HW specific resources if 340 * received ABORTS, errors, timeouts. 341 */ 342 void ft_invl_hw_context(struct ft_cmd *cmd) 343 { 344 struct fc_seq *seq; 345 struct fc_exch *ep = NULL; 346 struct fc_lport *lport = NULL; 347 348 BUG_ON(!cmd); 349 seq = cmd->seq; 350 351 /* Cleanup the DDP context in HW if DDP was setup */ 352 if (cmd->was_ddp_setup && seq) { 353 ep = fc_seq_exch(seq); 354 if (ep) { 355 lport = ep->lp; 356 if (lport && (ep->xid <= lport->lro_xid)) { 357 /* 358 * "ddp_done" trigger invalidation of HW 359 * specific DDP context 360 */ 361 cmd->write_data_len = lport->tt.ddp_done(lport, 362 ep->xid); 363 364 /* 365 * Resetting same variable to indicate HW's 366 * DDP context has been invalidated to avoid 367 * re_invalidation of same context (context is 368 * identified using ep->xid) 369 */ 370 cmd->was_ddp_setup = 0; 371 } 372 } 373 } 374 } 375