2 * Copyright (c) 2010 Cisco Systems, Inc.
4 * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
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>
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.
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
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.
27 /* XXX TBD some includes may be extraneous */
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/utsname.h>
32 #include <linux/init.h>
33 #include <linux/slab.h>
34 #include <linux/kthread.h>
35 #include <linux/types.h>
36 #include <linux/string.h>
37 #include <linux/configfs.h>
38 #include <linux/ctype.h>
39 #include <linux/hash.h>
40 #include <linux/ratelimit.h>
41 #include <asm/unaligned.h>
42 #include <scsi/libfc.h>
43 #include <scsi/fc_encode.h>
45 #include <target/target_core_base.h>
46 #include <target/target_core_fabric.h>
47 #include <target/target_core_configfs.h>
48 #include <target/configfs_macros.h>
53 * Deliver read data back to initiator.
54 * XXX TBD handle resource problems later.
56 int ft_queue_data_in(struct se_cmd *se_cmd)
58 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
59 struct fc_frame *fp = NULL;
61 struct fc_lport *lport;
62 struct scatterlist *sg = NULL;
64 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
72 struct page *page = NULL;
82 if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
85 ep = fc_seq_exch(cmd->seq);
87 cmd->seq = lport->tt.seq_start_next(cmd->seq);
89 remaining = se_cmd->data_length;
92 * Setup to use first mem list entry, unless no data.
94 BUG_ON(remaining && !se_cmd->t_data_sg);
96 sg = se_cmd->t_data_sg;
102 /* no scatter/gather in skb for odd word length due to fc_seq_send() */
103 use_sg = !(remaining % 4);
106 struct fc_seq *seq = cmd->seq;
109 pr_debug("%s: Command aborted, xid 0x%x\n",
115 mem_len = min((size_t)sg->length, remaining);
116 mem_off = sg->offset;
121 * If lport's has capability of Large Send Offload LSO)
122 * , then allow 'frame_len' to be as big as 'lso_max'
123 * if indicated transfer length is >= lport->lso_max
125 frame_len = (lport->seq_offload) ? lport->lso_max :
126 cmd->sess->max_frame;
127 frame_len = min(frame_len, remaining);
128 fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
131 to = fc_frame_payload_get(fp, 0);
133 frame_off += frame_len;
135 * Setup the frame's max payload which is used by base
136 * driver to indicate HW about max frame size, so that
137 * HW can do fragmentation appropriately based on
138 * "gso_max_size" of underline netdev.
140 fr_max_payload(fp) = cmd->sess->max_frame;
142 tlen = min(mem_len, frame_len);
145 off_in_page = mem_off;
148 skb_fill_page_desc(fp_skb(fp),
149 skb_shinfo(fp_skb(fp))->nr_frags,
150 page, off_in_page, tlen);
152 fp_skb(fp)->data_len += tlen;
153 fp_skb(fp)->truesize +=
154 PAGE_SIZE << compound_order(page);
157 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
159 from += mem_off & ~PAGE_MASK;
160 tlen = min(tlen, (size_t)(PAGE_SIZE -
161 (mem_off & ~PAGE_MASK)));
162 memcpy(to, from, tlen);
163 kunmap_atomic(page_addr);
173 (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
176 f_ctl |= FC_FC_END_SEQ;
177 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
178 FC_TYPE_FCP, f_ctl, fh_off);
179 error = lport->tt.seq_send(lport, seq, fp);
181 pr_info_ratelimited("%s: Failed to send frame %p, "
182 "xid <0x%x>, remaining %zu, "
184 __func__, fp, ep->xid,
185 remaining, lport->lso_max);
187 * Go ahead and set TASK_SET_FULL status ignoring the
188 * rest of the DataIN, and immediately attempt to
189 * send the response via ft_queue_status() in order
190 * to notify the initiator that it should reduce it's
191 * per LUN queue_depth.
193 se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
198 return ft_queue_status(se_cmd);
201 static void ft_execute_work(struct work_struct *work)
203 struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
205 target_execute_cmd(&cmd->se_cmd);
209 * Receive write data frame.
211 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
213 struct se_cmd *se_cmd = &cmd->se_cmd;
214 struct fc_seq *seq = cmd->seq;
216 struct fc_lport *lport;
217 struct fc_frame_header *fh;
218 struct scatterlist *sg = NULL;
224 struct page *page = NULL;
231 fh = fc_frame_header_get(fp);
232 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
235 f_ctl = ntoh24(fh->fh_f_ctl);
236 ep = fc_seq_exch(seq);
238 if (cmd->was_ddp_setup) {
242 * Since DDP (Large Rx offload) was setup for this request,
243 * payload is expected to be copied directly to user buffers.
245 buf = fc_frame_payload_get(fp, 1);
247 pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
248 "cmd->sg_cnt 0x%x. DDP was setup"
249 " hence not expected to receive frame with "
250 "payload, Frame will be dropped if"
251 "'Sequence Initiative' bit in f_ctl is"
252 "not set\n", __func__, ep->xid, f_ctl,
253 se_cmd->t_data_sg, se_cmd->t_data_nents);
255 * Invalidate HW DDP context if it was setup for respective
256 * command. Invalidation of HW DDP context is requited in both
257 * situation (success and error).
259 ft_invl_hw_context(cmd);
262 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
263 * write data frame is received successfully where payload is
264 * posted directly to user buffer and only the last frame's
265 * header is posted in receive queue.
267 * If "Sequence Initiative (TSI)" bit is not set, means error
268 * condition w.r.t. DDP, hence drop the packet and let explict
269 * ABORTS from other end of exchange timer trigger the recovery.
271 if (f_ctl & FC_FC_SEQ_INIT)
277 rel_off = ntohl(fh->fh_parm_offset);
278 frame_len = fr_len(fp);
279 if (frame_len <= sizeof(*fh))
281 frame_len -= sizeof(*fh);
282 from = fc_frame_payload_get(fp, 0);
283 if (rel_off >= se_cmd->data_length)
285 if (frame_len + rel_off > se_cmd->data_length)
286 frame_len = se_cmd->data_length - rel_off;
289 * Setup to use first mem list entry, unless no data.
291 BUG_ON(frame_len && !se_cmd->t_data_sg);
293 sg = se_cmd->t_data_sg;
294 mem_len = sg->length;
295 mem_off = sg->offset;
302 mem_len = sg->length;
303 mem_off = sg->offset;
306 if (rel_off >= mem_len) {
315 tlen = min(mem_len, frame_len);
317 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
319 to += mem_off & ~PAGE_MASK;
320 tlen = min(tlen, (size_t)(PAGE_SIZE -
321 (mem_off & ~PAGE_MASK)));
322 memcpy(to, from, tlen);
323 kunmap_atomic(page_addr);
329 cmd->write_data_len += tlen;
332 if (cmd->write_data_len == se_cmd->data_length) {
333 INIT_WORK(&cmd->work, ft_execute_work);
334 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
341 * Handle and cleanup any HW specific resources if
342 * received ABORTS, errors, timeouts.
344 void ft_invl_hw_context(struct ft_cmd *cmd)
347 struct fc_exch *ep = NULL;
348 struct fc_lport *lport = NULL;
353 /* Cleanup the DDP context in HW if DDP was setup */
354 if (cmd->was_ddp_setup && seq) {
355 ep = fc_seq_exch(seq);
358 if (lport && (ep->xid <= lport->lro_xid)) {
360 * "ddp_done" trigger invalidation of HW
361 * specific DDP context
363 cmd->write_data_len = lport->tt.ddp_done(lport,
367 * Resetting same variable to indicate HW's
368 * DDP context has been invalidated to avoid
369 * re_invalidation of same context (context is
370 * identified using ep->xid)
372 cmd->was_ddp_setup = 0;