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/version.h> 32 #include <generated/utsrelease.h> 33 #include <linux/utsname.h> 34 #include <linux/init.h> 35 #include <linux/slab.h> 36 #include <linux/kthread.h> 37 #include <linux/types.h> 38 #include <linux/string.h> 39 #include <linux/configfs.h> 40 #include <linux/ctype.h> 41 #include <linux/hash.h> 42 #include <linux/ratelimit.h> 43 #include <asm/unaligned.h> 44 #include <scsi/scsi.h> 45 #include <scsi/scsi_host.h> 46 #include <scsi/scsi_device.h> 47 #include <scsi/scsi_cmnd.h> 48 #include <scsi/libfc.h> 49 #include <scsi/fc_encode.h> 50 51 #include <target/target_core_base.h> 52 #include <target/target_core_transport.h> 53 #include <target/target_core_fabric_ops.h> 54 #include <target/target_core_device.h> 55 #include <target/target_core_tpg.h> 56 #include <target/target_core_configfs.h> 57 #include <target/configfs_macros.h> 58 59 #include "tcm_fc.h" 60 61 /* 62 * Deliver read data back to initiator. 63 * XXX TBD handle resource problems later. 64 */ 65 int ft_queue_data_in(struct se_cmd *se_cmd) 66 { 67 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 68 struct fc_frame *fp = NULL; 69 struct fc_exch *ep; 70 struct fc_lport *lport; 71 struct scatterlist *sg = NULL; 72 size_t remaining; 73 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 74 u32 mem_off = 0; 75 u32 fh_off = 0; 76 u32 frame_off = 0; 77 size_t frame_len = 0; 78 size_t mem_len = 0; 79 size_t tlen; 80 size_t off_in_page; 81 struct page *page = NULL; 82 int use_sg; 83 int error; 84 void *page_addr; 85 void *from; 86 void *to = NULL; 87 88 ep = fc_seq_exch(cmd->seq); 89 lport = ep->lp; 90 cmd->seq = lport->tt.seq_start_next(cmd->seq); 91 92 remaining = se_cmd->data_length; 93 94 /* 95 * Setup to use first mem list entry, unless no data. 96 */ 97 BUG_ON(remaining && !se_cmd->t_data_sg); 98 if (remaining) { 99 sg = se_cmd->t_data_sg; 100 mem_len = sg->length; 101 mem_off = sg->offset; 102 page = sg_page(sg); 103 } 104 105 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 106 use_sg = !(remaining % 4); 107 108 while (remaining) { 109 if (!mem_len) { 110 sg = sg_next(sg); 111 mem_len = min((size_t)sg->length, remaining); 112 mem_off = sg->offset; 113 page = sg_page(sg); 114 } 115 if (!frame_len) { 116 /* 117 * If lport's has capability of Large Send Offload LSO) 118 * , then allow 'frame_len' to be as big as 'lso_max' 119 * if indicated transfer length is >= lport->lso_max 120 */ 121 frame_len = (lport->seq_offload) ? lport->lso_max : 122 cmd->sess->max_frame; 123 frame_len = min(frame_len, remaining); 124 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 125 if (!fp) 126 return -ENOMEM; 127 to = fc_frame_payload_get(fp, 0); 128 fh_off = frame_off; 129 frame_off += frame_len; 130 /* 131 * Setup the frame's max payload which is used by base 132 * driver to indicate HW about max frame size, so that 133 * HW can do fragmentation appropriately based on 134 * "gso_max_size" of underline netdev. 135 */ 136 fr_max_payload(fp) = cmd->sess->max_frame; 137 } 138 tlen = min(mem_len, frame_len); 139 140 if (use_sg) { 141 off_in_page = mem_off; 142 BUG_ON(!page); 143 get_page(page); 144 skb_fill_page_desc(fp_skb(fp), 145 skb_shinfo(fp_skb(fp))->nr_frags, 146 page, off_in_page, tlen); 147 fr_len(fp) += tlen; 148 fp_skb(fp)->data_len += tlen; 149 fp_skb(fp)->truesize += 150 PAGE_SIZE << compound_order(page); 151 } else { 152 BUG_ON(!page); 153 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT), 154 KM_SOFTIRQ0); 155 page_addr = from; 156 from += mem_off & ~PAGE_MASK; 157 tlen = min(tlen, (size_t)(PAGE_SIZE - 158 (mem_off & ~PAGE_MASK))); 159 memcpy(to, from, tlen); 160 kunmap_atomic(page_addr, KM_SOFTIRQ0); 161 to += tlen; 162 } 163 164 mem_off += tlen; 165 mem_len -= tlen; 166 frame_len -= tlen; 167 remaining -= tlen; 168 169 if (frame_len && 170 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 171 continue; 172 if (!remaining) 173 f_ctl |= FC_FC_END_SEQ; 174 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 175 FC_TYPE_FCP, f_ctl, fh_off); 176 error = lport->tt.seq_send(lport, cmd->seq, fp); 177 if (error) { 178 /* XXX For now, initiator will retry */ 179 pr_err_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 } 186 return ft_queue_status(se_cmd); 187 } 188 189 /* 190 * Receive write data frame. 191 */ 192 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 193 { 194 struct se_cmd *se_cmd = &cmd->se_cmd; 195 struct fc_seq *seq = cmd->seq; 196 struct fc_exch *ep; 197 struct fc_lport *lport; 198 struct fc_frame_header *fh; 199 struct scatterlist *sg = NULL; 200 u32 mem_off = 0; 201 u32 rel_off; 202 size_t frame_len; 203 size_t mem_len = 0; 204 size_t tlen; 205 struct page *page = NULL; 206 void *page_addr; 207 void *from; 208 void *to; 209 u32 f_ctl; 210 void *buf; 211 212 fh = fc_frame_header_get(fp); 213 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 214 goto drop; 215 216 f_ctl = ntoh24(fh->fh_f_ctl); 217 ep = fc_seq_exch(seq); 218 lport = ep->lp; 219 if (cmd->was_ddp_setup) { 220 BUG_ON(!ep); 221 BUG_ON(!lport); 222 /* 223 * Since DDP (Large Rx offload) was setup for this request, 224 * payload is expected to be copied directly to user buffers. 225 */ 226 buf = fc_frame_payload_get(fp, 1); 227 if (buf) 228 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 229 "cmd->sg_cnt 0x%x. DDP was setup" 230 " hence not expected to receive frame with " 231 "payload, Frame will be dropped if" 232 "'Sequence Initiative' bit in f_ctl is" 233 "not set\n", __func__, ep->xid, f_ctl, 234 cmd->sg, cmd->sg_cnt); 235 /* 236 * Invalidate HW DDP context if it was setup for respective 237 * command. Invalidation of HW DDP context is requited in both 238 * situation (success and error). 239 */ 240 ft_invl_hw_context(cmd); 241 242 /* 243 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 244 * write data frame is received successfully where payload is 245 * posted directly to user buffer and only the last frame's 246 * header is posted in receive queue. 247 * 248 * If "Sequence Initiative (TSI)" bit is not set, means error 249 * condition w.r.t. DDP, hence drop the packet and let explict 250 * ABORTS from other end of exchange timer trigger the recovery. 251 */ 252 if (f_ctl & FC_FC_SEQ_INIT) 253 goto last_frame; 254 else 255 goto drop; 256 } 257 258 rel_off = ntohl(fh->fh_parm_offset); 259 frame_len = fr_len(fp); 260 if (frame_len <= sizeof(*fh)) 261 goto drop; 262 frame_len -= sizeof(*fh); 263 from = fc_frame_payload_get(fp, 0); 264 if (rel_off >= se_cmd->data_length) 265 goto drop; 266 if (frame_len + rel_off > se_cmd->data_length) 267 frame_len = se_cmd->data_length - rel_off; 268 269 /* 270 * Setup to use first mem list entry, unless no data. 271 */ 272 BUG_ON(frame_len && !se_cmd->t_data_sg); 273 if (frame_len) { 274 sg = se_cmd->t_data_sg; 275 mem_len = sg->length; 276 mem_off = sg->offset; 277 page = sg_page(sg); 278 } 279 280 while (frame_len) { 281 if (!mem_len) { 282 sg = sg_next(sg); 283 mem_len = sg->length; 284 mem_off = sg->offset; 285 page = sg_page(sg); 286 } 287 if (rel_off >= mem_len) { 288 rel_off -= mem_len; 289 mem_len = 0; 290 continue; 291 } 292 mem_off += rel_off; 293 mem_len -= rel_off; 294 rel_off = 0; 295 296 tlen = min(mem_len, frame_len); 297 298 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT), 299 KM_SOFTIRQ0); 300 page_addr = to; 301 to += mem_off & ~PAGE_MASK; 302 tlen = min(tlen, (size_t)(PAGE_SIZE - 303 (mem_off & ~PAGE_MASK))); 304 memcpy(to, from, tlen); 305 kunmap_atomic(page_addr, KM_SOFTIRQ0); 306 307 from += tlen; 308 frame_len -= tlen; 309 mem_off += tlen; 310 mem_len -= tlen; 311 cmd->write_data_len += tlen; 312 } 313 last_frame: 314 if (cmd->write_data_len == se_cmd->data_length) 315 transport_generic_handle_data(se_cmd); 316 drop: 317 fc_frame_free(fp); 318 } 319 320 /* 321 * Handle and cleanup any HW specific resources if 322 * received ABORTS, errors, timeouts. 323 */ 324 void ft_invl_hw_context(struct ft_cmd *cmd) 325 { 326 struct fc_seq *seq = cmd->seq; 327 struct fc_exch *ep = NULL; 328 struct fc_lport *lport = NULL; 329 330 BUG_ON(!cmd); 331 332 /* Cleanup the DDP context in HW if DDP was setup */ 333 if (cmd->was_ddp_setup && seq) { 334 ep = fc_seq_exch(seq); 335 if (ep) { 336 lport = ep->lp; 337 if (lport && (ep->xid <= lport->lro_xid)) 338 /* 339 * "ddp_done" trigger invalidation of HW 340 * specific DDP context 341 */ 342 cmd->write_data_len = lport->tt.ddp_done(lport, 343 ep->xid); 344 345 /* 346 * Resetting same variable to indicate HW's 347 * DDP context has been invalidated to avoid 348 * re_invalidation of same context (context is 349 * identified using ep->xid) 350 */ 351 cmd->was_ddp_setup = 0; 352 } 353 } 354 } 355