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 ep = fc_seq_exch(cmd->seq); 85 lport = ep->lp; 86 cmd->seq = lport->tt.seq_start_next(cmd->seq); 87 88 remaining = se_cmd->data_length; 89 90 /* 91 * Setup to use first mem list entry, unless no data. 92 */ 93 BUG_ON(remaining && !se_cmd->t_data_sg); 94 if (remaining) { 95 sg = se_cmd->t_data_sg; 96 mem_len = sg->length; 97 mem_off = sg->offset; 98 page = sg_page(sg); 99 } 100 101 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 102 use_sg = !(remaining % 4); 103 104 while (remaining) { 105 if (!mem_len) { 106 sg = sg_next(sg); 107 mem_len = min((size_t)sg->length, remaining); 108 mem_off = sg->offset; 109 page = sg_page(sg); 110 } 111 if (!frame_len) { 112 /* 113 * If lport's has capability of Large Send Offload LSO) 114 * , then allow 'frame_len' to be as big as 'lso_max' 115 * if indicated transfer length is >= lport->lso_max 116 */ 117 frame_len = (lport->seq_offload) ? lport->lso_max : 118 cmd->sess->max_frame; 119 frame_len = min(frame_len, remaining); 120 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 121 if (!fp) 122 return -ENOMEM; 123 to = fc_frame_payload_get(fp, 0); 124 fh_off = frame_off; 125 frame_off += frame_len; 126 /* 127 * Setup the frame's max payload which is used by base 128 * driver to indicate HW about max frame size, so that 129 * HW can do fragmentation appropriately based on 130 * "gso_max_size" of underline netdev. 131 */ 132 fr_max_payload(fp) = cmd->sess->max_frame; 133 } 134 tlen = min(mem_len, frame_len); 135 136 if (use_sg) { 137 off_in_page = mem_off; 138 BUG_ON(!page); 139 get_page(page); 140 skb_fill_page_desc(fp_skb(fp), 141 skb_shinfo(fp_skb(fp))->nr_frags, 142 page, off_in_page, tlen); 143 fr_len(fp) += tlen; 144 fp_skb(fp)->data_len += tlen; 145 fp_skb(fp)->truesize += 146 PAGE_SIZE << compound_order(page); 147 } else { 148 BUG_ON(!page); 149 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 150 page_addr = from; 151 from += mem_off & ~PAGE_MASK; 152 tlen = min(tlen, (size_t)(PAGE_SIZE - 153 (mem_off & ~PAGE_MASK))); 154 memcpy(to, from, tlen); 155 kunmap_atomic(page_addr); 156 to += tlen; 157 } 158 159 mem_off += tlen; 160 mem_len -= tlen; 161 frame_len -= tlen; 162 remaining -= tlen; 163 164 if (frame_len && 165 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 166 continue; 167 if (!remaining) 168 f_ctl |= FC_FC_END_SEQ; 169 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 170 FC_TYPE_FCP, f_ctl, fh_off); 171 error = lport->tt.seq_send(lport, cmd->seq, fp); 172 if (error) { 173 /* XXX For now, initiator will retry */ 174 pr_err_ratelimited("%s: Failed to send frame %p, " 175 "xid <0x%x>, remaining %zu, " 176 "lso_max <0x%x>\n", 177 __func__, fp, ep->xid, 178 remaining, lport->lso_max); 179 } 180 } 181 return ft_queue_status(se_cmd); 182 } 183 184 /* 185 * Receive write data frame. 186 */ 187 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 188 { 189 struct se_cmd *se_cmd = &cmd->se_cmd; 190 struct fc_seq *seq = cmd->seq; 191 struct fc_exch *ep; 192 struct fc_lport *lport; 193 struct fc_frame_header *fh; 194 struct scatterlist *sg = NULL; 195 u32 mem_off = 0; 196 u32 rel_off; 197 size_t frame_len; 198 size_t mem_len = 0; 199 size_t tlen; 200 struct page *page = NULL; 201 void *page_addr; 202 void *from; 203 void *to; 204 u32 f_ctl; 205 void *buf; 206 207 fh = fc_frame_header_get(fp); 208 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 209 goto drop; 210 211 f_ctl = ntoh24(fh->fh_f_ctl); 212 ep = fc_seq_exch(seq); 213 lport = ep->lp; 214 if (cmd->was_ddp_setup) { 215 BUG_ON(!ep); 216 BUG_ON(!lport); 217 /* 218 * Since DDP (Large Rx offload) was setup for this request, 219 * payload is expected to be copied directly to user buffers. 220 */ 221 buf = fc_frame_payload_get(fp, 1); 222 if (buf) 223 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 224 "cmd->sg_cnt 0x%x. DDP was setup" 225 " hence not expected to receive frame with " 226 "payload, Frame will be dropped if" 227 "'Sequence Initiative' bit in f_ctl is" 228 "not set\n", __func__, ep->xid, f_ctl, 229 cmd->sg, cmd->sg_cnt); 230 /* 231 * Invalidate HW DDP context if it was setup for respective 232 * command. Invalidation of HW DDP context is requited in both 233 * situation (success and error). 234 */ 235 ft_invl_hw_context(cmd); 236 237 /* 238 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 239 * write data frame is received successfully where payload is 240 * posted directly to user buffer and only the last frame's 241 * header is posted in receive queue. 242 * 243 * If "Sequence Initiative (TSI)" bit is not set, means error 244 * condition w.r.t. DDP, hence drop the packet and let explict 245 * ABORTS from other end of exchange timer trigger the recovery. 246 */ 247 if (f_ctl & FC_FC_SEQ_INIT) 248 goto last_frame; 249 else 250 goto drop; 251 } 252 253 rel_off = ntohl(fh->fh_parm_offset); 254 frame_len = fr_len(fp); 255 if (frame_len <= sizeof(*fh)) 256 goto drop; 257 frame_len -= sizeof(*fh); 258 from = fc_frame_payload_get(fp, 0); 259 if (rel_off >= se_cmd->data_length) 260 goto drop; 261 if (frame_len + rel_off > se_cmd->data_length) 262 frame_len = se_cmd->data_length - rel_off; 263 264 /* 265 * Setup to use first mem list entry, unless no data. 266 */ 267 BUG_ON(frame_len && !se_cmd->t_data_sg); 268 if (frame_len) { 269 sg = se_cmd->t_data_sg; 270 mem_len = sg->length; 271 mem_off = sg->offset; 272 page = sg_page(sg); 273 } 274 275 while (frame_len) { 276 if (!mem_len) { 277 sg = sg_next(sg); 278 mem_len = sg->length; 279 mem_off = sg->offset; 280 page = sg_page(sg); 281 } 282 if (rel_off >= mem_len) { 283 rel_off -= mem_len; 284 mem_len = 0; 285 continue; 286 } 287 mem_off += rel_off; 288 mem_len -= rel_off; 289 rel_off = 0; 290 291 tlen = min(mem_len, frame_len); 292 293 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 294 page_addr = to; 295 to += mem_off & ~PAGE_MASK; 296 tlen = min(tlen, (size_t)(PAGE_SIZE - 297 (mem_off & ~PAGE_MASK))); 298 memcpy(to, from, tlen); 299 kunmap_atomic(page_addr); 300 301 from += tlen; 302 frame_len -= tlen; 303 mem_off += tlen; 304 mem_len -= tlen; 305 cmd->write_data_len += tlen; 306 } 307 last_frame: 308 if (cmd->write_data_len == se_cmd->data_length) 309 transport_generic_handle_data(se_cmd); 310 drop: 311 fc_frame_free(fp); 312 } 313 314 /* 315 * Handle and cleanup any HW specific resources if 316 * received ABORTS, errors, timeouts. 317 */ 318 void ft_invl_hw_context(struct ft_cmd *cmd) 319 { 320 struct fc_seq *seq = cmd->seq; 321 struct fc_exch *ep = NULL; 322 struct fc_lport *lport = NULL; 323 324 BUG_ON(!cmd); 325 326 /* Cleanup the DDP context in HW if DDP was setup */ 327 if (cmd->was_ddp_setup && seq) { 328 ep = fc_seq_exch(seq); 329 if (ep) { 330 lport = ep->lp; 331 if (lport && (ep->xid <= lport->lro_xid)) 332 /* 333 * "ddp_done" trigger invalidation of HW 334 * specific DDP context 335 */ 336 cmd->write_data_len = lport->tt.ddp_done(lport, 337 ep->xid); 338 339 /* 340 * Resetting same variable to indicate HW's 341 * DDP context has been invalidated to avoid 342 * re_invalidation of same context (context is 343 * identified using ep->xid) 344 */ 345 cmd->was_ddp_setup = 0; 346 } 347 } 348 } 349