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/target_core_configfs.h> 48 #include <target/configfs_macros.h> 49 50 #include "tcm_fc.h" 51 52 /* 53 * Deliver read data back to initiator. 54 * XXX TBD handle resource problems later. 55 */ 56 int ft_queue_data_in(struct se_cmd *se_cmd) 57 { 58 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 59 struct fc_frame *fp = NULL; 60 struct fc_exch *ep; 61 struct fc_lport *lport; 62 struct scatterlist *sg = NULL; 63 size_t remaining; 64 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 65 u32 mem_off = 0; 66 u32 fh_off = 0; 67 u32 frame_off = 0; 68 size_t frame_len = 0; 69 size_t mem_len = 0; 70 size_t tlen; 71 size_t off_in_page; 72 struct page *page = NULL; 73 int use_sg; 74 int error; 75 void *page_addr; 76 void *from; 77 void *to = NULL; 78 79 if (cmd->aborted) 80 return 0; 81 82 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) 83 goto queue_status; 84 85 ep = fc_seq_exch(cmd->seq); 86 lport = ep->lp; 87 cmd->seq = lport->tt.seq_start_next(cmd->seq); 88 89 remaining = se_cmd->data_length; 90 91 /* 92 * Setup to use first mem list entry, unless no data. 93 */ 94 BUG_ON(remaining && !se_cmd->t_data_sg); 95 if (remaining) { 96 sg = se_cmd->t_data_sg; 97 mem_len = sg->length; 98 mem_off = sg->offset; 99 page = sg_page(sg); 100 } 101 102 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 103 use_sg = !(remaining % 4); 104 105 while (remaining) { 106 struct fc_seq *seq = cmd->seq; 107 108 if (!seq) { 109 pr_debug("%s: Command aborted, xid 0x%x\n", 110 __func__, ep->xid); 111 break; 112 } 113 if (!mem_len) { 114 sg = sg_next(sg); 115 mem_len = min((size_t)sg->length, remaining); 116 mem_off = sg->offset; 117 page = sg_page(sg); 118 } 119 if (!frame_len) { 120 /* 121 * If lport's has capability of Large Send Offload LSO) 122 * , then allow 'frame_len' to be as big as 'lso_max' 123 * if indicated transfer length is >= lport->lso_max 124 */ 125 frame_len = (lport->seq_offload) ? lport->lso_max : 126 cmd->sess->max_frame; 127 frame_len = min(frame_len, remaining); 128 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 129 if (!fp) 130 return -ENOMEM; 131 to = fc_frame_payload_get(fp, 0); 132 fh_off = frame_off; 133 frame_off += frame_len; 134 /* 135 * Setup the frame's max payload which is used by base 136 * driver to indicate HW about max frame size, so that 137 * HW can do fragmentation appropriately based on 138 * "gso_max_size" of underline netdev. 139 */ 140 fr_max_payload(fp) = cmd->sess->max_frame; 141 } 142 tlen = min(mem_len, frame_len); 143 144 if (use_sg) { 145 off_in_page = mem_off; 146 BUG_ON(!page); 147 get_page(page); 148 skb_fill_page_desc(fp_skb(fp), 149 skb_shinfo(fp_skb(fp))->nr_frags, 150 page, off_in_page, tlen); 151 fr_len(fp) += tlen; 152 fp_skb(fp)->data_len += tlen; 153 fp_skb(fp)->truesize += 154 PAGE_SIZE << compound_order(page); 155 } else { 156 BUG_ON(!page); 157 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 158 page_addr = from; 159 from += mem_off & ~PAGE_MASK; 160 tlen = min(tlen, (size_t)(PAGE_SIZE - 161 (mem_off & ~PAGE_MASK))); 162 memcpy(to, from, tlen); 163 kunmap_atomic(page_addr); 164 to += tlen; 165 } 166 167 mem_off += tlen; 168 mem_len -= tlen; 169 frame_len -= tlen; 170 remaining -= tlen; 171 172 if (frame_len && 173 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 174 continue; 175 if (!remaining) 176 f_ctl |= FC_FC_END_SEQ; 177 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 178 FC_TYPE_FCP, f_ctl, fh_off); 179 error = lport->tt.seq_send(lport, seq, fp); 180 if (error) { 181 pr_info_ratelimited("%s: Failed to send frame %p, " 182 "xid <0x%x>, remaining %zu, " 183 "lso_max <0x%x>\n", 184 __func__, fp, ep->xid, 185 remaining, lport->lso_max); 186 /* 187 * Go ahead and set TASK_SET_FULL status ignoring the 188 * rest of the DataIN, and immediately attempt to 189 * send the response via ft_queue_status() in order 190 * to notify the initiator that it should reduce it's 191 * per LUN queue_depth. 192 */ 193 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 194 break; 195 } 196 } 197 queue_status: 198 return ft_queue_status(se_cmd); 199 } 200 201 static void ft_execute_work(struct work_struct *work) 202 { 203 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 204 205 target_execute_cmd(&cmd->se_cmd); 206 } 207 208 /* 209 * Receive write data frame. 210 */ 211 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 212 { 213 struct se_cmd *se_cmd = &cmd->se_cmd; 214 struct fc_seq *seq = cmd->seq; 215 struct fc_exch *ep; 216 struct fc_lport *lport; 217 struct fc_frame_header *fh; 218 struct scatterlist *sg = NULL; 219 u32 mem_off = 0; 220 u32 rel_off; 221 size_t frame_len; 222 size_t mem_len = 0; 223 size_t tlen; 224 struct page *page = NULL; 225 void *page_addr; 226 void *from; 227 void *to; 228 u32 f_ctl; 229 void *buf; 230 231 fh = fc_frame_header_get(fp); 232 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 233 goto drop; 234 235 f_ctl = ntoh24(fh->fh_f_ctl); 236 ep = fc_seq_exch(seq); 237 lport = ep->lp; 238 if (cmd->was_ddp_setup) { 239 BUG_ON(!ep); 240 BUG_ON(!lport); 241 /* 242 * Since DDP (Large Rx offload) was setup for this request, 243 * payload is expected to be copied directly to user buffers. 244 */ 245 buf = fc_frame_payload_get(fp, 1); 246 if (buf) 247 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 248 "cmd->sg_cnt 0x%x. DDP was setup" 249 " hence not expected to receive frame with " 250 "payload, Frame will be dropped if" 251 "'Sequence Initiative' bit in f_ctl is" 252 "not set\n", __func__, ep->xid, f_ctl, 253 se_cmd->t_data_sg, se_cmd->t_data_nents); 254 /* 255 * Invalidate HW DDP context if it was setup for respective 256 * command. Invalidation of HW DDP context is requited in both 257 * situation (success and error). 258 */ 259 ft_invl_hw_context(cmd); 260 261 /* 262 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 263 * write data frame is received successfully where payload is 264 * posted directly to user buffer and only the last frame's 265 * header is posted in receive queue. 266 * 267 * If "Sequence Initiative (TSI)" bit is not set, means error 268 * condition w.r.t. DDP, hence drop the packet and let explict 269 * ABORTS from other end of exchange timer trigger the recovery. 270 */ 271 if (f_ctl & FC_FC_SEQ_INIT) 272 goto last_frame; 273 else 274 goto drop; 275 } 276 277 rel_off = ntohl(fh->fh_parm_offset); 278 frame_len = fr_len(fp); 279 if (frame_len <= sizeof(*fh)) 280 goto drop; 281 frame_len -= sizeof(*fh); 282 from = fc_frame_payload_get(fp, 0); 283 if (rel_off >= se_cmd->data_length) 284 goto drop; 285 if (frame_len + rel_off > se_cmd->data_length) 286 frame_len = se_cmd->data_length - rel_off; 287 288 /* 289 * Setup to use first mem list entry, unless no data. 290 */ 291 BUG_ON(frame_len && !se_cmd->t_data_sg); 292 if (frame_len) { 293 sg = se_cmd->t_data_sg; 294 mem_len = sg->length; 295 mem_off = sg->offset; 296 page = sg_page(sg); 297 } 298 299 while (frame_len) { 300 if (!mem_len) { 301 sg = sg_next(sg); 302 mem_len = sg->length; 303 mem_off = sg->offset; 304 page = sg_page(sg); 305 } 306 if (rel_off >= mem_len) { 307 rel_off -= mem_len; 308 mem_len = 0; 309 continue; 310 } 311 mem_off += rel_off; 312 mem_len -= rel_off; 313 rel_off = 0; 314 315 tlen = min(mem_len, frame_len); 316 317 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 318 page_addr = to; 319 to += mem_off & ~PAGE_MASK; 320 tlen = min(tlen, (size_t)(PAGE_SIZE - 321 (mem_off & ~PAGE_MASK))); 322 memcpy(to, from, tlen); 323 kunmap_atomic(page_addr); 324 325 from += tlen; 326 frame_len -= tlen; 327 mem_off += tlen; 328 mem_len -= tlen; 329 cmd->write_data_len += tlen; 330 } 331 last_frame: 332 if (cmd->write_data_len == se_cmd->data_length) { 333 INIT_WORK(&cmd->work, ft_execute_work); 334 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 335 } 336 drop: 337 fc_frame_free(fp); 338 } 339 340 /* 341 * Handle and cleanup any HW specific resources if 342 * received ABORTS, errors, timeouts. 343 */ 344 void ft_invl_hw_context(struct ft_cmd *cmd) 345 { 346 struct fc_seq *seq; 347 struct fc_exch *ep = NULL; 348 struct fc_lport *lport = NULL; 349 350 BUG_ON(!cmd); 351 seq = cmd->seq; 352 353 /* Cleanup the DDP context in HW if DDP was setup */ 354 if (cmd->was_ddp_setup && seq) { 355 ep = fc_seq_exch(seq); 356 if (ep) { 357 lport = ep->lp; 358 if (lport && (ep->xid <= lport->lro_xid)) { 359 /* 360 * "ddp_done" trigger invalidation of HW 361 * specific DDP context 362 */ 363 cmd->write_data_len = lport->tt.ddp_done(lport, 364 ep->xid); 365 366 /* 367 * Resetting same variable to indicate HW's 368 * DDP context has been invalidated to avoid 369 * re_invalidation of same context (context is 370 * identified using ep->xid) 371 */ 372 cmd->was_ddp_setup = 0; 373 } 374 } 375 } 376 } 377