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/scsi.h> 43 #include <scsi/scsi_host.h> 44 #include <scsi/scsi_device.h> 45 #include <scsi/scsi_cmnd.h> 46 #include <scsi/libfc.h> 47 #include <scsi/fc_encode.h> 48 49 #include <target/target_core_base.h> 50 #include <target/target_core_fabric.h> 51 #include <target/target_core_configfs.h> 52 #include <target/configfs_macros.h> 53 54 #include "tcm_fc.h" 55 56 /* 57 * Deliver read data back to initiator. 58 * XXX TBD handle resource problems later. 59 */ 60 int ft_queue_data_in(struct se_cmd *se_cmd) 61 { 62 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 63 struct fc_frame *fp = NULL; 64 struct fc_exch *ep; 65 struct fc_lport *lport; 66 struct scatterlist *sg = NULL; 67 size_t remaining; 68 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 69 u32 mem_off = 0; 70 u32 fh_off = 0; 71 u32 frame_off = 0; 72 size_t frame_len = 0; 73 size_t mem_len = 0; 74 size_t tlen; 75 size_t off_in_page; 76 struct page *page = NULL; 77 int use_sg; 78 int error; 79 void *page_addr; 80 void *from; 81 void *to = NULL; 82 83 if (cmd->aborted) 84 return 0; 85 86 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) 87 goto queue_status; 88 89 ep = fc_seq_exch(cmd->seq); 90 lport = ep->lp; 91 cmd->seq = lport->tt.seq_start_next(cmd->seq); 92 93 remaining = se_cmd->data_length; 94 95 /* 96 * Setup to use first mem list entry, unless no data. 97 */ 98 BUG_ON(remaining && !se_cmd->t_data_sg); 99 if (remaining) { 100 sg = se_cmd->t_data_sg; 101 mem_len = sg->length; 102 mem_off = sg->offset; 103 page = sg_page(sg); 104 } 105 106 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 107 use_sg = !(remaining % 4); 108 109 while (remaining) { 110 struct fc_seq *seq = cmd->seq; 111 112 if (!seq) { 113 pr_debug("%s: Command aborted, xid 0x%x\n", 114 __func__, ep->xid); 115 break; 116 } 117 if (!mem_len) { 118 sg = sg_next(sg); 119 mem_len = min((size_t)sg->length, remaining); 120 mem_off = sg->offset; 121 page = sg_page(sg); 122 } 123 if (!frame_len) { 124 /* 125 * If lport's has capability of Large Send Offload LSO) 126 * , then allow 'frame_len' to be as big as 'lso_max' 127 * if indicated transfer length is >= lport->lso_max 128 */ 129 frame_len = (lport->seq_offload) ? lport->lso_max : 130 cmd->sess->max_frame; 131 frame_len = min(frame_len, remaining); 132 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 133 if (!fp) 134 return -ENOMEM; 135 to = fc_frame_payload_get(fp, 0); 136 fh_off = frame_off; 137 frame_off += frame_len; 138 /* 139 * Setup the frame's max payload which is used by base 140 * driver to indicate HW about max frame size, so that 141 * HW can do fragmentation appropriately based on 142 * "gso_max_size" of underline netdev. 143 */ 144 fr_max_payload(fp) = cmd->sess->max_frame; 145 } 146 tlen = min(mem_len, frame_len); 147 148 if (use_sg) { 149 off_in_page = mem_off; 150 BUG_ON(!page); 151 get_page(page); 152 skb_fill_page_desc(fp_skb(fp), 153 skb_shinfo(fp_skb(fp))->nr_frags, 154 page, off_in_page, tlen); 155 fr_len(fp) += tlen; 156 fp_skb(fp)->data_len += tlen; 157 fp_skb(fp)->truesize += 158 PAGE_SIZE << compound_order(page); 159 } else { 160 BUG_ON(!page); 161 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 162 page_addr = from; 163 from += mem_off & ~PAGE_MASK; 164 tlen = min(tlen, (size_t)(PAGE_SIZE - 165 (mem_off & ~PAGE_MASK))); 166 memcpy(to, from, tlen); 167 kunmap_atomic(page_addr); 168 to += tlen; 169 } 170 171 mem_off += tlen; 172 mem_len -= tlen; 173 frame_len -= tlen; 174 remaining -= tlen; 175 176 if (frame_len && 177 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 178 continue; 179 if (!remaining) 180 f_ctl |= FC_FC_END_SEQ; 181 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 182 FC_TYPE_FCP, f_ctl, fh_off); 183 error = lport->tt.seq_send(lport, seq, fp); 184 if (error) { 185 pr_info_ratelimited("%s: Failed to send frame %p, " 186 "xid <0x%x>, remaining %zu, " 187 "lso_max <0x%x>\n", 188 __func__, fp, ep->xid, 189 remaining, lport->lso_max); 190 /* 191 * Go ahead and set TASK_SET_FULL status ignoring the 192 * rest of the DataIN, and immediately attempt to 193 * send the response via ft_queue_status() in order 194 * to notify the initiator that it should reduce it's 195 * per LUN queue_depth. 196 */ 197 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 198 break; 199 } 200 } 201 queue_status: 202 return ft_queue_status(se_cmd); 203 } 204 205 static void ft_execute_work(struct work_struct *work) 206 { 207 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 208 209 target_execute_cmd(&cmd->se_cmd); 210 } 211 212 /* 213 * Receive write data frame. 214 */ 215 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 216 { 217 struct se_cmd *se_cmd = &cmd->se_cmd; 218 struct fc_seq *seq = cmd->seq; 219 struct fc_exch *ep; 220 struct fc_lport *lport; 221 struct fc_frame_header *fh; 222 struct scatterlist *sg = NULL; 223 u32 mem_off = 0; 224 u32 rel_off; 225 size_t frame_len; 226 size_t mem_len = 0; 227 size_t tlen; 228 struct page *page = NULL; 229 void *page_addr; 230 void *from; 231 void *to; 232 u32 f_ctl; 233 void *buf; 234 235 fh = fc_frame_header_get(fp); 236 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 237 goto drop; 238 239 f_ctl = ntoh24(fh->fh_f_ctl); 240 ep = fc_seq_exch(seq); 241 lport = ep->lp; 242 if (cmd->was_ddp_setup) { 243 BUG_ON(!ep); 244 BUG_ON(!lport); 245 /* 246 * Since DDP (Large Rx offload) was setup for this request, 247 * payload is expected to be copied directly to user buffers. 248 */ 249 buf = fc_frame_payload_get(fp, 1); 250 if (buf) 251 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 252 "cmd->sg_cnt 0x%x. DDP was setup" 253 " hence not expected to receive frame with " 254 "payload, Frame will be dropped if" 255 "'Sequence Initiative' bit in f_ctl is" 256 "not set\n", __func__, ep->xid, f_ctl, 257 se_cmd->t_data_sg, se_cmd->t_data_nents); 258 /* 259 * Invalidate HW DDP context if it was setup for respective 260 * command. Invalidation of HW DDP context is requited in both 261 * situation (success and error). 262 */ 263 ft_invl_hw_context(cmd); 264 265 /* 266 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 267 * write data frame is received successfully where payload is 268 * posted directly to user buffer and only the last frame's 269 * header is posted in receive queue. 270 * 271 * If "Sequence Initiative (TSI)" bit is not set, means error 272 * condition w.r.t. DDP, hence drop the packet and let explict 273 * ABORTS from other end of exchange timer trigger the recovery. 274 */ 275 if (f_ctl & FC_FC_SEQ_INIT) 276 goto last_frame; 277 else 278 goto drop; 279 } 280 281 rel_off = ntohl(fh->fh_parm_offset); 282 frame_len = fr_len(fp); 283 if (frame_len <= sizeof(*fh)) 284 goto drop; 285 frame_len -= sizeof(*fh); 286 from = fc_frame_payload_get(fp, 0); 287 if (rel_off >= se_cmd->data_length) 288 goto drop; 289 if (frame_len + rel_off > se_cmd->data_length) 290 frame_len = se_cmd->data_length - rel_off; 291 292 /* 293 * Setup to use first mem list entry, unless no data. 294 */ 295 BUG_ON(frame_len && !se_cmd->t_data_sg); 296 if (frame_len) { 297 sg = se_cmd->t_data_sg; 298 mem_len = sg->length; 299 mem_off = sg->offset; 300 page = sg_page(sg); 301 } 302 303 while (frame_len) { 304 if (!mem_len) { 305 sg = sg_next(sg); 306 mem_len = sg->length; 307 mem_off = sg->offset; 308 page = sg_page(sg); 309 } 310 if (rel_off >= mem_len) { 311 rel_off -= mem_len; 312 mem_len = 0; 313 continue; 314 } 315 mem_off += rel_off; 316 mem_len -= rel_off; 317 rel_off = 0; 318 319 tlen = min(mem_len, frame_len); 320 321 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 322 page_addr = to; 323 to += mem_off & ~PAGE_MASK; 324 tlen = min(tlen, (size_t)(PAGE_SIZE - 325 (mem_off & ~PAGE_MASK))); 326 memcpy(to, from, tlen); 327 kunmap_atomic(page_addr); 328 329 from += tlen; 330 frame_len -= tlen; 331 mem_off += tlen; 332 mem_len -= tlen; 333 cmd->write_data_len += tlen; 334 } 335 last_frame: 336 if (cmd->write_data_len == se_cmd->data_length) { 337 INIT_WORK(&cmd->work, ft_execute_work); 338 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 339 } 340 drop: 341 fc_frame_free(fp); 342 } 343 344 /* 345 * Handle and cleanup any HW specific resources if 346 * received ABORTS, errors, timeouts. 347 */ 348 void ft_invl_hw_context(struct ft_cmd *cmd) 349 { 350 struct fc_seq *seq; 351 struct fc_exch *ep = NULL; 352 struct fc_lport *lport = NULL; 353 354 BUG_ON(!cmd); 355 seq = cmd->seq; 356 357 /* Cleanup the DDP context in HW if DDP was setup */ 358 if (cmd->was_ddp_setup && seq) { 359 ep = fc_seq_exch(seq); 360 if (ep) { 361 lport = ep->lp; 362 if (lport && (ep->xid <= lport->lro_xid)) { 363 /* 364 * "ddp_done" trigger invalidation of HW 365 * specific DDP context 366 */ 367 cmd->write_data_len = lport->tt.ddp_done(lport, 368 ep->xid); 369 370 /* 371 * Resetting same variable to indicate HW's 372 * DDP context has been invalidated to avoid 373 * re_invalidation of same context (context is 374 * identified using ep->xid) 375 */ 376 cmd->was_ddp_setup = 0; 377 } 378 } 379 } 380 } 381