1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2010 Cisco Systems, Inc. 4 * 5 * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c 6 * 7 * Copyright (c) 2007 Intel Corporation. All rights reserved. 8 * Copyright (c) 2008 Red Hat, Inc. All rights reserved. 9 * Copyright (c) 2008 Mike Christie 10 * Copyright (c) 2009 Rising Tide, Inc. 11 * Copyright (c) 2009 Linux-iSCSI.org 12 * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org> 13 */ 14 15 /* XXX TBD some includes may be extraneous */ 16 17 #include <linux/module.h> 18 #include <linux/moduleparam.h> 19 #include <linux/utsname.h> 20 #include <linux/init.h> 21 #include <linux/slab.h> 22 #include <linux/kthread.h> 23 #include <linux/types.h> 24 #include <linux/string.h> 25 #include <linux/configfs.h> 26 #include <linux/ctype.h> 27 #include <linux/hash.h> 28 #include <linux/ratelimit.h> 29 #include <asm/unaligned.h> 30 #include <scsi/libfc.h> 31 32 #include <target/target_core_base.h> 33 #include <target/target_core_fabric.h> 34 35 #include "tcm_fc.h" 36 37 /* 38 * Deliver read data back to initiator. 39 * XXX TBD handle resource problems later. 40 */ 41 int ft_queue_data_in(struct se_cmd *se_cmd) 42 { 43 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd); 44 struct fc_frame *fp = NULL; 45 struct fc_exch *ep; 46 struct fc_lport *lport; 47 struct scatterlist *sg = NULL; 48 size_t remaining; 49 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; 50 u32 mem_off = 0; 51 u32 fh_off = 0; 52 u32 frame_off = 0; 53 size_t frame_len = 0; 54 size_t mem_len = 0; 55 size_t tlen; 56 size_t off_in_page; 57 struct page *page = NULL; 58 int use_sg; 59 int error; 60 void *page_addr; 61 void *from; 62 void *to = NULL; 63 64 if (cmd->aborted) 65 return 0; 66 67 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL) 68 goto queue_status; 69 70 ep = fc_seq_exch(cmd->seq); 71 lport = ep->lp; 72 cmd->seq = fc_seq_start_next(cmd->seq); 73 74 remaining = se_cmd->data_length; 75 76 /* 77 * Setup to use first mem list entry, unless no data. 78 */ 79 BUG_ON(remaining && !se_cmd->t_data_sg); 80 if (remaining) { 81 sg = se_cmd->t_data_sg; 82 mem_len = sg->length; 83 mem_off = sg->offset; 84 page = sg_page(sg); 85 } 86 87 /* no scatter/gather in skb for odd word length due to fc_seq_send() */ 88 use_sg = !(remaining % 4); 89 90 while (remaining) { 91 struct fc_seq *seq = cmd->seq; 92 93 if (!seq) { 94 pr_debug("%s: Command aborted, xid 0x%x\n", 95 __func__, ep->xid); 96 break; 97 } 98 if (!mem_len) { 99 sg = sg_next(sg); 100 mem_len = min((size_t)sg->length, remaining); 101 mem_off = sg->offset; 102 page = sg_page(sg); 103 } 104 if (!frame_len) { 105 /* 106 * If lport's has capability of Large Send Offload LSO) 107 * , then allow 'frame_len' to be as big as 'lso_max' 108 * if indicated transfer length is >= lport->lso_max 109 */ 110 frame_len = (lport->seq_offload) ? lport->lso_max : 111 cmd->sess->max_frame; 112 frame_len = min(frame_len, remaining); 113 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len); 114 if (!fp) 115 return -ENOMEM; 116 to = fc_frame_payload_get(fp, 0); 117 fh_off = frame_off; 118 frame_off += frame_len; 119 /* 120 * Setup the frame's max payload which is used by base 121 * driver to indicate HW about max frame size, so that 122 * HW can do fragmentation appropriately based on 123 * "gso_max_size" of underline netdev. 124 */ 125 fr_max_payload(fp) = cmd->sess->max_frame; 126 } 127 tlen = min(mem_len, frame_len); 128 129 if (use_sg) { 130 off_in_page = mem_off; 131 BUG_ON(!page); 132 get_page(page); 133 skb_fill_page_desc(fp_skb(fp), 134 skb_shinfo(fp_skb(fp))->nr_frags, 135 page, off_in_page, tlen); 136 fr_len(fp) += tlen; 137 fp_skb(fp)->data_len += tlen; 138 fp_skb(fp)->truesize += page_size(page); 139 } else { 140 BUG_ON(!page); 141 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 142 page_addr = from; 143 from += offset_in_page(mem_off); 144 tlen = min(tlen, (size_t)(PAGE_SIZE - 145 offset_in_page(mem_off))); 146 memcpy(to, from, tlen); 147 kunmap_atomic(page_addr); 148 to += tlen; 149 } 150 151 mem_off += tlen; 152 mem_len -= tlen; 153 frame_len -= tlen; 154 remaining -= tlen; 155 156 if (frame_len && 157 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN)) 158 continue; 159 if (!remaining) 160 f_ctl |= FC_FC_END_SEQ; 161 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid, 162 FC_TYPE_FCP, f_ctl, fh_off); 163 error = fc_seq_send(lport, seq, fp); 164 if (error) { 165 pr_info_ratelimited("%s: Failed to send frame %p, " 166 "xid <0x%x>, remaining %zu, " 167 "lso_max <0x%x>\n", 168 __func__, fp, ep->xid, 169 remaining, lport->lso_max); 170 /* 171 * Go ahead and set TASK_SET_FULL status ignoring the 172 * rest of the DataIN, and immediately attempt to 173 * send the response via ft_queue_status() in order 174 * to notify the initiator that it should reduce it's 175 * per LUN queue_depth. 176 */ 177 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL; 178 break; 179 } 180 } 181 queue_status: 182 return ft_queue_status(se_cmd); 183 } 184 185 static void ft_execute_work(struct work_struct *work) 186 { 187 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); 188 189 target_execute_cmd(&cmd->se_cmd); 190 } 191 192 /* 193 * Receive write data frame. 194 */ 195 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp) 196 { 197 struct se_cmd *se_cmd = &cmd->se_cmd; 198 struct fc_seq *seq = cmd->seq; 199 struct fc_exch *ep; 200 struct fc_lport *lport; 201 struct fc_frame_header *fh; 202 struct scatterlist *sg = NULL; 203 u32 mem_off = 0; 204 u32 rel_off; 205 size_t frame_len; 206 size_t mem_len = 0; 207 size_t tlen; 208 struct page *page = NULL; 209 void *page_addr; 210 void *from; 211 void *to; 212 u32 f_ctl; 213 void *buf; 214 215 fh = fc_frame_header_get(fp); 216 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF)) 217 goto drop; 218 219 f_ctl = ntoh24(fh->fh_f_ctl); 220 ep = fc_seq_exch(seq); 221 lport = ep->lp; 222 if (cmd->was_ddp_setup) { 223 BUG_ON(!lport); 224 /* 225 * Since DDP (Large Rx offload) was setup for this request, 226 * payload is expected to be copied directly to user buffers. 227 */ 228 buf = fc_frame_payload_get(fp, 1); 229 if (buf) 230 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " 231 "cmd->sg_cnt 0x%x. DDP was setup" 232 " hence not expected to receive frame with " 233 "payload, Frame will be dropped if" 234 "'Sequence Initiative' bit in f_ctl is" 235 "not set\n", __func__, ep->xid, f_ctl, 236 se_cmd->t_data_sg, se_cmd->t_data_nents); 237 /* 238 * Invalidate HW DDP context if it was setup for respective 239 * command. Invalidation of HW DDP context is requited in both 240 * situation (success and error). 241 */ 242 ft_invl_hw_context(cmd); 243 244 /* 245 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last 246 * write data frame is received successfully where payload is 247 * posted directly to user buffer and only the last frame's 248 * header is posted in receive queue. 249 * 250 * If "Sequence Initiative (TSI)" bit is not set, means error 251 * condition w.r.t. DDP, hence drop the packet and let explict 252 * ABORTS from other end of exchange timer trigger the recovery. 253 */ 254 if (f_ctl & FC_FC_SEQ_INIT) 255 goto last_frame; 256 else 257 goto drop; 258 } 259 260 rel_off = ntohl(fh->fh_parm_offset); 261 frame_len = fr_len(fp); 262 if (frame_len <= sizeof(*fh)) 263 goto drop; 264 frame_len -= sizeof(*fh); 265 from = fc_frame_payload_get(fp, 0); 266 if (rel_off >= se_cmd->data_length) 267 goto drop; 268 if (frame_len + rel_off > se_cmd->data_length) 269 frame_len = se_cmd->data_length - rel_off; 270 271 /* 272 * Setup to use first mem list entry, unless no data. 273 */ 274 BUG_ON(frame_len && !se_cmd->t_data_sg); 275 if (frame_len) { 276 sg = se_cmd->t_data_sg; 277 mem_len = sg->length; 278 mem_off = sg->offset; 279 page = sg_page(sg); 280 } 281 282 while (frame_len) { 283 if (!mem_len) { 284 sg = sg_next(sg); 285 mem_len = sg->length; 286 mem_off = sg->offset; 287 page = sg_page(sg); 288 } 289 if (rel_off >= mem_len) { 290 rel_off -= mem_len; 291 mem_len = 0; 292 continue; 293 } 294 mem_off += rel_off; 295 mem_len -= rel_off; 296 rel_off = 0; 297 298 tlen = min(mem_len, frame_len); 299 300 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT)); 301 page_addr = to; 302 to += offset_in_page(mem_off); 303 tlen = min(tlen, (size_t)(PAGE_SIZE - 304 offset_in_page(mem_off))); 305 memcpy(to, from, tlen); 306 kunmap_atomic(page_addr); 307 308 from += tlen; 309 frame_len -= tlen; 310 mem_off += tlen; 311 mem_len -= tlen; 312 cmd->write_data_len += tlen; 313 } 314 last_frame: 315 if (cmd->write_data_len == se_cmd->data_length) { 316 INIT_WORK(&cmd->work, ft_execute_work); 317 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); 318 } 319 drop: 320 fc_frame_free(fp); 321 } 322 323 /* 324 * Handle and cleanup any HW specific resources if 325 * received ABORTS, errors, timeouts. 326 */ 327 void ft_invl_hw_context(struct ft_cmd *cmd) 328 { 329 struct fc_seq *seq; 330 struct fc_exch *ep = NULL; 331 struct fc_lport *lport = NULL; 332 333 BUG_ON(!cmd); 334 seq = cmd->seq; 335 336 /* Cleanup the DDP context in HW if DDP was setup */ 337 if (cmd->was_ddp_setup && seq) { 338 ep = fc_seq_exch(seq); 339 if (ep) { 340 lport = ep->lp; 341 if (lport && (ep->xid <= lport->lro_xid)) { 342 /* 343 * "ddp_done" trigger invalidation of HW 344 * specific DDP context 345 */ 346 cmd->write_data_len = lport->tt.ddp_done(lport, 347 ep->xid); 348 349 /* 350 * Resetting same variable to indicate HW's 351 * DDP context has been invalidated to avoid 352 * re_invalidation of same context (context is 353 * identified using ep->xid) 354 */ 355 cmd->was_ddp_setup = 0; 356 } 357 } 358 } 359 } 360