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 <generated/utsrelease.h> 32 #include <linux/utsname.h> 33 #include <linux/init.h> 34 #include <linux/slab.h> 35 #include <linux/kthread.h> 36 #include <linux/types.h> 37 #include <linux/string.h> 38 #include <linux/configfs.h> 39 #include <linux/ctype.h> 40 #include <linux/hash.h> 41 #include <linux/ratelimit.h> 42 #include <asm/unaligned.h> 43 #include <scsi/scsi.h> 44 #include <scsi/scsi_host.h> 45 #include <scsi/scsi_device.h> 46 #include <scsi/scsi_cmnd.h> 47 #include <scsi/libfc.h> 48 #include <scsi/fc_encode.h> 49 50 #include <target/target_core_base.h> 51 #include <target/target_core_fabric.h> 52 #include <target/target_core_configfs.h> 53 #include <target/configfs_macros.h> 54 55 #include "tcm_fc.h" 56 57 /* 58 * Deliver read data back to initiator. 59 * XXX TBD handle resource problems later. 60 */ 61 int ft_queue_data_in(struct se_cmd *se_cmd) 62 { 63 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 64 struct fc_frame *fp = NULL; 65 struct fc_exch *ep; 66 struct fc_lport *lport; 67 struct scatterlist *sg = NULL; 68 size_t remaining; 69 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 70 u32 mem_off = 0; 71 u32 fh_off = 0; 72 u32 frame_off = 0; 73 size_t frame_len = 0; 74 size_t mem_len = 0; 75 size_t tlen; 76 size_t off_in_page; 77 struct page *page = NULL; 78 int use_sg; 79 int error; 80 void *page_addr; 81 void *from; 82 void *to = NULL; 83 84 if (cmd->aborted) 85 return 0; 86 ep = fc_seq_exch(cmd->seq); 87 lport = ep->lp; 88 cmd->seq = lport->tt.seq_start_next(cmd->seq); 89 90 remaining = se_cmd->data_length; 91 92 /* 93 * Setup to use first mem list entry, unless no data. 94 */ 95 BUG_ON(remaining && !se_cmd->t_data_sg); 96 if (remaining) { 97 sg = se_cmd->t_data_sg; 98 mem_len = sg->length; 99 mem_off = sg->offset; 100 page = sg_page(sg); 101 } 102 103 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 104 use_sg = !(remaining % 4); 105 106 while (remaining) { 107 if (!mem_len) { 108 sg = sg_next(sg); 109 mem_len = min((size_t)sg->length, remaining); 110 mem_off = sg->offset; 111 page = sg_page(sg); 112 } 113 if (!frame_len) { 114 /* 115 * If lport's has capability of Large Send Offload LSO) 116 * , then allow 'frame_len' to be as big as 'lso_max' 117 * if indicated transfer length is >= lport->lso_max 118 */ 119 frame_len = (lport->seq_offload) ? lport->lso_max : 120 cmd->sess->max_frame; 121 frame_len = min(frame_len, remaining); 122 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 123 if (!fp) 124 return -ENOMEM; 125 to = fc_frame_payload_get(fp, 0); 126 fh_off = frame_off; 127 frame_off += frame_len; 128 /* 129 * Setup the frame's max payload which is used by base 130 * driver to indicate HW about max frame size, so that 131 * HW can do fragmentation appropriately based on 132 * "gso_max_size" of underline netdev. 133 */ 134 fr_max_payload(fp) = cmd->sess->max_frame; 135 } 136 tlen = min(mem_len, frame_len); 137 138 if (use_sg) { 139 off_in_page = mem_off; 140 BUG_ON(!page); 141 get_page(page); 142 skb_fill_page_desc(fp_skb(fp), 143 skb_shinfo(fp_skb(fp))->nr_frags, 144 page, off_in_page, tlen); 145 fr_len(fp) += tlen; 146 fp_skb(fp)->data_len += tlen; 147 fp_skb(fp)->truesize += 148 PAGE_SIZE << compound_order(page); 149 } else { 150 BUG_ON(!page); 151 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 152 page_addr = from; 153 from += mem_off & ~PAGE_MASK; 154 tlen = min(tlen, (size_t)(PAGE_SIZE - 155 (mem_off & ~PAGE_MASK))); 156 memcpy(to, from, tlen); 157 kunmap_atomic(page_addr); 158 to += tlen; 159 } 160 161 mem_off += tlen; 162 mem_len -= tlen; 163 frame_len -= tlen; 164 remaining -= tlen; 165 166 if (frame_len && 167 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 168 continue; 169 if (!remaining) 170 f_ctl |= FC_FC_END_SEQ; 171 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 172 FC_TYPE_FCP, f_ctl, fh_off); 173 error = lport->tt.seq_send(lport, cmd->seq, fp); 174 if (error) { 175 /* XXX For now, initiator will retry */ 176 pr_err_ratelimited("%s: Failed to send frame %p, " 177 "xid <0x%x>, remaining %zu, " 178 "lso_max <0x%x>\n", 179 __func__, fp, ep->xid, 180 remaining, lport->lso_max); 181 } 182 } 183 return ft_queue_status(se_cmd); 184 } 185 186 static void ft_execute_work(struct work_struct *work) 187 { 188 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 189 190 target_execute_cmd(&cmd->se_cmd); 191 } 192 193 /* 194 * Receive write data frame. 195 */ 196 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 197 { 198 struct se_cmd *se_cmd = &cmd->se_cmd; 199 struct fc_seq *seq = cmd->seq; 200 struct fc_exch *ep; 201 struct fc_lport *lport; 202 struct fc_frame_header *fh; 203 struct scatterlist *sg = NULL; 204 u32 mem_off = 0; 205 u32 rel_off; 206 size_t frame_len; 207 size_t mem_len = 0; 208 size_t tlen; 209 struct page *page = NULL; 210 void *page_addr; 211 void *from; 212 void *to; 213 u32 f_ctl; 214 void *buf; 215 216 fh = fc_frame_header_get(fp); 217 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 218 goto drop; 219 220 f_ctl = ntoh24(fh->fh_f_ctl); 221 ep = fc_seq_exch(seq); 222 lport = ep->lp; 223 if (cmd->was_ddp_setup) { 224 BUG_ON(!ep); 225 BUG_ON(!lport); 226 /* 227 * Since DDP (Large Rx offload) was setup for this request, 228 * payload is expected to be copied directly to user buffers. 229 */ 230 buf = fc_frame_payload_get(fp, 1); 231 if (buf) 232 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 233 "cmd->sg_cnt 0x%x. DDP was setup" 234 " hence not expected to receive frame with " 235 "payload, Frame will be dropped if" 236 "'Sequence Initiative' bit in f_ctl is" 237 "not set\n", __func__, ep->xid, f_ctl, 238 se_cmd->t_data_sg, se_cmd->t_data_nents); 239 /* 240 * Invalidate HW DDP context if it was setup for respective 241 * command. Invalidation of HW DDP context is requited in both 242 * situation (success and error). 243 */ 244 ft_invl_hw_context(cmd); 245 246 /* 247 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 248 * write data frame is received successfully where payload is 249 * posted directly to user buffer and only the last frame's 250 * header is posted in receive queue. 251 * 252 * If "Sequence Initiative (TSI)" bit is not set, means error 253 * condition w.r.t. DDP, hence drop the packet and let explict 254 * ABORTS from other end of exchange timer trigger the recovery. 255 */ 256 if (f_ctl & FC_FC_SEQ_INIT) 257 goto last_frame; 258 else 259 goto drop; 260 } 261 262 rel_off = ntohl(fh->fh_parm_offset); 263 frame_len = fr_len(fp); 264 if (frame_len <= sizeof(*fh)) 265 goto drop; 266 frame_len -= sizeof(*fh); 267 from = fc_frame_payload_get(fp, 0); 268 if (rel_off >= se_cmd->data_length) 269 goto drop; 270 if (frame_len + rel_off > se_cmd->data_length) 271 frame_len = se_cmd->data_length - rel_off; 272 273 /* 274 * Setup to use first mem list entry, unless no data. 275 */ 276 BUG_ON(frame_len && !se_cmd->t_data_sg); 277 if (frame_len) { 278 sg = se_cmd->t_data_sg; 279 mem_len = sg->length; 280 mem_off = sg->offset; 281 page = sg_page(sg); 282 } 283 284 while (frame_len) { 285 if (!mem_len) { 286 sg = sg_next(sg); 287 mem_len = sg->length; 288 mem_off = sg->offset; 289 page = sg_page(sg); 290 } 291 if (rel_off >= mem_len) { 292 rel_off -= mem_len; 293 mem_len = 0; 294 continue; 295 } 296 mem_off += rel_off; 297 mem_len -= rel_off; 298 rel_off = 0; 299 300 tlen = min(mem_len, frame_len); 301 302 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 303 page_addr = to; 304 to += mem_off & ~PAGE_MASK; 305 tlen = min(tlen, (size_t)(PAGE_SIZE - 306 (mem_off & ~PAGE_MASK))); 307 memcpy(to, from, tlen); 308 kunmap_atomic(page_addr); 309 310 from += tlen; 311 frame_len -= tlen; 312 mem_off += tlen; 313 mem_len -= tlen; 314 cmd->write_data_len += tlen; 315 } 316 last_frame: 317 if (cmd->write_data_len == se_cmd->data_length) { 318 INIT_WORK(&cmd->work, ft_execute_work); 319 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 320 } 321 drop: 322 fc_frame_free(fp); 323 } 324 325 /* 326 * Handle and cleanup any HW specific resources if 327 * received ABORTS, errors, timeouts. 328 */ 329 void ft_invl_hw_context(struct ft_cmd *cmd) 330 { 331 struct fc_seq *seq = cmd->seq; 332 struct fc_exch *ep = NULL; 333 struct fc_lport *lport = NULL; 334 335 BUG_ON(!cmd); 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