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