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 /* 187 * Receive write data frame. 188 */ 189 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 190 { 191 struct se_cmd *se_cmd = &cmd->se_cmd; 192 struct fc_seq *seq = cmd->seq; 193 struct fc_exch *ep; 194 struct fc_lport *lport; 195 struct fc_frame_header *fh; 196 struct scatterlist *sg = NULL; 197 u32 mem_off = 0; 198 u32 rel_off; 199 size_t frame_len; 200 size_t mem_len = 0; 201 size_t tlen; 202 struct page *page = NULL; 203 void *page_addr; 204 void *from; 205 void *to; 206 u32 f_ctl; 207 void *buf; 208 209 fh = fc_frame_header_get(fp); 210 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 211 goto drop; 212 213 f_ctl = ntoh24(fh->fh_f_ctl); 214 ep = fc_seq_exch(seq); 215 lport = ep->lp; 216 if (cmd->was_ddp_setup) { 217 BUG_ON(!ep); 218 BUG_ON(!lport); 219 /* 220 * Since DDP (Large Rx offload) was setup for this request, 221 * payload is expected to be copied directly to user buffers. 222 */ 223 buf = fc_frame_payload_get(fp, 1); 224 if (buf) 225 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 226 "cmd->sg_cnt 0x%x. DDP was setup" 227 " hence not expected to receive frame with " 228 "payload, Frame will be dropped if" 229 "'Sequence Initiative' bit in f_ctl is" 230 "not set\n", __func__, ep->xid, f_ctl, 231 cmd->sg, cmd->sg_cnt); 232 /* 233 * Invalidate HW DDP context if it was setup for respective 234 * command. Invalidation of HW DDP context is requited in both 235 * situation (success and error). 236 */ 237 ft_invl_hw_context(cmd); 238 239 /* 240 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 241 * write data frame is received successfully where payload is 242 * posted directly to user buffer and only the last frame's 243 * header is posted in receive queue. 244 * 245 * If "Sequence Initiative (TSI)" bit is not set, means error 246 * condition w.r.t. DDP, hence drop the packet and let explict 247 * ABORTS from other end of exchange timer trigger the recovery. 248 */ 249 if (f_ctl & FC_FC_SEQ_INIT) 250 goto last_frame; 251 else 252 goto drop; 253 } 254 255 rel_off = ntohl(fh->fh_parm_offset); 256 frame_len = fr_len(fp); 257 if (frame_len <= sizeof(*fh)) 258 goto drop; 259 frame_len -= sizeof(*fh); 260 from = fc_frame_payload_get(fp, 0); 261 if (rel_off >= se_cmd->data_length) 262 goto drop; 263 if (frame_len + rel_off > se_cmd->data_length) 264 frame_len = se_cmd->data_length - rel_off; 265 266 /* 267 * Setup to use first mem list entry, unless no data. 268 */ 269 BUG_ON(frame_len && !se_cmd->t_data_sg); 270 if (frame_len) { 271 sg = se_cmd->t_data_sg; 272 mem_len = sg->length; 273 mem_off = sg->offset; 274 page = sg_page(sg); 275 } 276 277 while (frame_len) { 278 if (!mem_len) { 279 sg = sg_next(sg); 280 mem_len = sg->length; 281 mem_off = sg->offset; 282 page = sg_page(sg); 283 } 284 if (rel_off >= mem_len) { 285 rel_off -= mem_len; 286 mem_len = 0; 287 continue; 288 } 289 mem_off += rel_off; 290 mem_len -= rel_off; 291 rel_off = 0; 292 293 tlen = min(mem_len, frame_len); 294 295 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 296 page_addr = to; 297 to += mem_off & ~PAGE_MASK; 298 tlen = min(tlen, (size_t)(PAGE_SIZE - 299 (mem_off & ~PAGE_MASK))); 300 memcpy(to, from, tlen); 301 kunmap_atomic(page_addr); 302 303 from += tlen; 304 frame_len -= tlen; 305 mem_off += tlen; 306 mem_len -= tlen; 307 cmd->write_data_len += tlen; 308 } 309 last_frame: 310 if (cmd->write_data_len == se_cmd->data_length) 311 transport_generic_handle_data(se_cmd); 312 drop: 313 fc_frame_free(fp); 314 } 315 316 /* 317 * Handle and cleanup any HW specific resources if 318 * received ABORTS, errors, timeouts. 319 */ 320 void ft_invl_hw_context(struct ft_cmd *cmd) 321 { 322 struct fc_seq *seq = cmd->seq; 323 struct fc_exch *ep = NULL; 324 struct fc_lport *lport = NULL; 325 326 BUG_ON(!cmd); 327 328 /* Cleanup the DDP context in HW if DDP was setup */ 329 if (cmd->was_ddp_setup && seq) { 330 ep = fc_seq_exch(seq); 331 if (ep) { 332 lport = ep->lp; 333 if (lport && (ep->xid <= lport->lro_xid)) 334 /* 335 * "ddp_done" trigger invalidation of HW 336 * specific DDP context 337 */ 338 cmd->write_data_len = lport->tt.ddp_done(lport, 339 ep->xid); 340 341 /* 342 * Resetting same variable to indicate HW's 343 * DDP context has been invalidated to avoid 344 * re_invalidation of same context (context is 345 * identified using ep->xid) 346 */ 347 cmd->was_ddp_setup = 0; 348 } 349 } 350 } 351