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_transport.h> 52 #include <target/target_core_fabric_ops.h> 53 #include <target/target_core_device.h> 54 #include <target/target_core_tpg.h> 55 #include <target/target_core_configfs.h> 56 #include <target/configfs_macros.h> 57 58 #include "tcm_fc.h" 59 60 /* 61 * Deliver read data back to initiator. 62 * XXX TBD handle resource problems later. 63 */ 64 int ft_queue_data_in(struct se_cmd *se_cmd) 65 { 66 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 67 struct fc_frame *fp = NULL; 68 struct fc_exch *ep; 69 struct fc_lport *lport; 70 struct scatterlist *sg = NULL; 71 size_t remaining; 72 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 73 u32 mem_off = 0; 74 u32 fh_off = 0; 75 u32 frame_off = 0; 76 size_t frame_len = 0; 77 size_t mem_len = 0; 78 size_t tlen; 79 size_t off_in_page; 80 struct page *page = NULL; 81 int use_sg; 82 int error; 83 void *page_addr; 84 void *from; 85 void *to = NULL; 86 87 ep = fc_seq_exch(cmd->seq); 88 lport = ep->lp; 89 cmd->seq = lport->tt.seq_start_next(cmd->seq); 90 91 remaining = se_cmd->data_length; 92 93 /* 94 * Setup to use first mem list entry, unless no data. 95 */ 96 BUG_ON(remaining && !se_cmd->t_data_sg); 97 if (remaining) { 98 sg = se_cmd->t_data_sg; 99 mem_len = sg->length; 100 mem_off = sg->offset; 101 page = sg_page(sg); 102 } 103 104 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 105 use_sg = !(remaining % 4); 106 107 while (remaining) { 108 if (!mem_len) { 109 sg = sg_next(sg); 110 mem_len = min((size_t)sg->length, remaining); 111 mem_off = sg->offset; 112 page = sg_page(sg); 113 } 114 if (!frame_len) { 115 /* 116 * If lport's has capability of Large Send Offload LSO) 117 * , then allow 'frame_len' to be as big as 'lso_max' 118 * if indicated transfer length is >= lport->lso_max 119 */ 120 frame_len = (lport->seq_offload) ? lport->lso_max : 121 cmd->sess->max_frame; 122 frame_len = min(frame_len, remaining); 123 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 124 if (!fp) 125 return -ENOMEM; 126 to = fc_frame_payload_get(fp, 0); 127 fh_off = frame_off; 128 frame_off += frame_len; 129 /* 130 * Setup the frame's max payload which is used by base 131 * driver to indicate HW about max frame size, so that 132 * HW can do fragmentation appropriately based on 133 * "gso_max_size" of underline netdev. 134 */ 135 fr_max_payload(fp) = cmd->sess->max_frame; 136 } 137 tlen = min(mem_len, frame_len); 138 139 if (use_sg) { 140 off_in_page = mem_off; 141 BUG_ON(!page); 142 get_page(page); 143 skb_fill_page_desc(fp_skb(fp), 144 skb_shinfo(fp_skb(fp))->nr_frags, 145 page, off_in_page, tlen); 146 fr_len(fp) += tlen; 147 fp_skb(fp)->data_len += tlen; 148 fp_skb(fp)->truesize += 149 PAGE_SIZE << compound_order(page); 150 } else { 151 BUG_ON(!page); 152 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT), 153 KM_SOFTIRQ0); 154 page_addr = from; 155 from += mem_off & ~PAGE_MASK; 156 tlen = min(tlen, (size_t)(PAGE_SIZE - 157 (mem_off & ~PAGE_MASK))); 158 memcpy(to, from, tlen); 159 kunmap_atomic(page_addr, KM_SOFTIRQ0); 160 to += tlen; 161 } 162 163 mem_off += tlen; 164 mem_len -= tlen; 165 frame_len -= tlen; 166 remaining -= tlen; 167 168 if (frame_len && 169 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 170 continue; 171 if (!remaining) 172 f_ctl |= FC_FC_END_SEQ; 173 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 174 FC_TYPE_FCP, f_ctl, fh_off); 175 error = lport->tt.seq_send(lport, cmd->seq, fp); 176 if (error) { 177 /* XXX For now, initiator will retry */ 178 pr_err_ratelimited("%s: Failed to send frame %p, " 179 "xid <0x%x>, remaining %zu, " 180 "lso_max <0x%x>\n", 181 __func__, fp, ep->xid, 182 remaining, lport->lso_max); 183 } 184 } 185 return ft_queue_status(se_cmd); 186 } 187 188 /* 189 * Receive write data frame. 190 */ 191 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 192 { 193 struct se_cmd *se_cmd = &cmd->se_cmd; 194 struct fc_seq *seq = cmd->seq; 195 struct fc_exch *ep; 196 struct fc_lport *lport; 197 struct fc_frame_header *fh; 198 struct scatterlist *sg = NULL; 199 u32 mem_off = 0; 200 u32 rel_off; 201 size_t frame_len; 202 size_t mem_len = 0; 203 size_t tlen; 204 struct page *page = NULL; 205 void *page_addr; 206 void *from; 207 void *to; 208 u32 f_ctl; 209 void *buf; 210 211 fh = fc_frame_header_get(fp); 212 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 213 goto drop; 214 215 f_ctl = ntoh24(fh->fh_f_ctl); 216 ep = fc_seq_exch(seq); 217 lport = ep->lp; 218 if (cmd->was_ddp_setup) { 219 BUG_ON(!ep); 220 BUG_ON(!lport); 221 /* 222 * Since DDP (Large Rx offload) was setup for this request, 223 * payload is expected to be copied directly to user buffers. 224 */ 225 buf = fc_frame_payload_get(fp, 1); 226 if (buf) 227 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 228 "cmd->sg_cnt 0x%x. DDP was setup" 229 " hence not expected to receive frame with " 230 "payload, Frame will be dropped if" 231 "'Sequence Initiative' bit in f_ctl is" 232 "not set\n", __func__, ep->xid, f_ctl, 233 cmd->sg, cmd->sg_cnt); 234 /* 235 * Invalidate HW DDP context if it was setup for respective 236 * command. Invalidation of HW DDP context is requited in both 237 * situation (success and error). 238 */ 239 ft_invl_hw_context(cmd); 240 241 /* 242 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 243 * write data frame is received successfully where payload is 244 * posted directly to user buffer and only the last frame's 245 * header is posted in receive queue. 246 * 247 * If "Sequence Initiative (TSI)" bit is not set, means error 248 * condition w.r.t. DDP, hence drop the packet and let explict 249 * ABORTS from other end of exchange timer trigger the recovery. 250 */ 251 if (f_ctl & FC_FC_SEQ_INIT) 252 goto last_frame; 253 else 254 goto drop; 255 } 256 257 rel_off = ntohl(fh->fh_parm_offset); 258 frame_len = fr_len(fp); 259 if (frame_len <= sizeof(*fh)) 260 goto drop; 261 frame_len -= sizeof(*fh); 262 from = fc_frame_payload_get(fp, 0); 263 if (rel_off >= se_cmd->data_length) 264 goto drop; 265 if (frame_len + rel_off > se_cmd->data_length) 266 frame_len = se_cmd->data_length - rel_off; 267 268 /* 269 * Setup to use first mem list entry, unless no data. 270 */ 271 BUG_ON(frame_len && !se_cmd->t_data_sg); 272 if (frame_len) { 273 sg = se_cmd->t_data_sg; 274 mem_len = sg->length; 275 mem_off = sg->offset; 276 page = sg_page(sg); 277 } 278 279 while (frame_len) { 280 if (!mem_len) { 281 sg = sg_next(sg); 282 mem_len = sg->length; 283 mem_off = sg->offset; 284 page = sg_page(sg); 285 } 286 if (rel_off >= mem_len) { 287 rel_off -= mem_len; 288 mem_len = 0; 289 continue; 290 } 291 mem_off += rel_off; 292 mem_len -= rel_off; 293 rel_off = 0; 294 295 tlen = min(mem_len, frame_len); 296 297 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT), 298 KM_SOFTIRQ0); 299 page_addr = to; 300 to += mem_off & ~PAGE_MASK; 301 tlen = min(tlen, (size_t)(PAGE_SIZE - 302 (mem_off & ~PAGE_MASK))); 303 memcpy(to, from, tlen); 304 kunmap_atomic(page_addr, KM_SOFTIRQ0); 305 306 from += tlen; 307 frame_len -= tlen; 308 mem_off += tlen; 309 mem_len -= tlen; 310 cmd->write_data_len += tlen; 311 } 312 last_frame: 313 if (cmd->write_data_len == se_cmd->data_length) 314 transport_generic_handle_data(se_cmd); 315 drop: 316 fc_frame_free(fp); 317 } 318 319 /* 320 * Handle and cleanup any HW specific resources if 321 * received ABORTS, errors, timeouts. 322 */ 323 void ft_invl_hw_context(struct ft_cmd *cmd) 324 { 325 struct fc_seq *seq = cmd->seq; 326 struct fc_exch *ep = NULL; 327 struct fc_lport *lport = NULL; 328 329 BUG_ON(!cmd); 330 331 /* Cleanup the DDP context in HW if DDP was setup */ 332 if (cmd->was_ddp_setup && seq) { 333 ep = fc_seq_exch(seq); 334 if (ep) { 335 lport = ep->lp; 336 if (lport && (ep->xid <= lport->lro_xid)) 337 /* 338 * "ddp_done" trigger invalidation of HW 339 * specific DDP context 340 */ 341 cmd->write_data_len = lport->tt.ddp_done(lport, 342 ep->xid); 343 344 /* 345 * Resetting same variable to indicate HW's 346 * DDP context has been invalidated to avoid 347 * re_invalidation of same context (context is 348 * identified using ep->xid) 349 */ 350 cmd->was_ddp_setup = 0; 351 } 352 } 353 } 354