tcm_fc: Remove use of transport_do_task_sg_chain()
[deliverable/linux.git] / drivers / target / tcm_fc / tfc_io.c
CommitLineData
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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>
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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>
6708bb27 41#include <linux/ratelimit.h>
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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>
c4795fb2 51#include <target/target_core_fabric.h>
3699d92a 52#include <target/target_core_configfs.h>
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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 */
61int ft_queue_data_in(struct se_cmd *se_cmd)
62{
63 struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
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64 struct fc_frame *fp = NULL;
65 struct fc_exch *ep;
66 struct fc_lport *lport;
ec98f782 67 struct scatterlist *sg = NULL;
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68 size_t remaining;
69 u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
ec98f782 70 u32 mem_off = 0;
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71 u32 fh_off = 0;
72 u32 frame_off = 0;
73 size_t frame_len = 0;
ec98f782 74 size_t mem_len = 0;
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75 size_t tlen;
76 size_t off_in_page;
ec98f782 77 struct page *page = NULL;
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78 int use_sg;
79 int error;
80 void *page_addr;
81 void *from;
82 void *to = NULL;
83
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84 if (cmd->aborted)
85 return 0;
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86 ep = fc_seq_exch(cmd->seq);
87 lport = ep->lp;
88 cmd->seq = lport->tt.seq_start_next(cmd->seq);
89
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90 remaining = se_cmd->data_length;
91
92 /*
05d1c7c0 93 * Setup to use first mem list entry, unless no data.
3699d92a 94 */
ec98f782 95 BUG_ON(remaining && !se_cmd->t_data_sg);
05d1c7c0 96 if (remaining) {
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97 sg = se_cmd->t_data_sg;
98 mem_len = sg->length;
99 mem_off = sg->offset;
100 page = sg_page(sg);
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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) {
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108 sg = sg_next(sg);
109 mem_len = min((size_t)sg->length, remaining);
110 mem_off = sg->offset;
111 page = sg_page(sg);
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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) {
05d1c7c0 139 off_in_page = mem_off;
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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);
05d1c7c0 149 } else {
3699d92a 150 BUG_ON(!page);
ca747d61 151 from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
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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);
ca747d61 157 kunmap_atomic(page_addr);
3699d92a 158 to += tlen;
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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 */
6708bb27 176 pr_err_ratelimited("%s: Failed to send frame %p, "
95efa286 177 "xid <0x%x>, remaining %zu, "
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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 */
189void 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;
3699d92a 195 struct fc_frame_header *fh;
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196 struct scatterlist *sg = NULL;
197 u32 mem_off = 0;
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198 u32 rel_off;
199 size_t frame_len;
ec98f782 200 size_t mem_len = 0;
3699d92a 201 size_t tlen;
ec98f782 202 struct page *page = NULL;
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203 void *page_addr;
204 void *from;
205 void *to;
206 u32 f_ctl;
207 void *buf;
208
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209 fh = fc_frame_header_get(fp);
210 if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
211 goto drop;
212
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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);
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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, "
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226 "cmd->sg_cnt 0x%x. DDP was setup"
227 " hence not expected to receive frame with "
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228 "payload, Frame will be dropped if"
229 "'Sequence Initiative' bit in f_ctl is"
dcd998cc 230 "not set\n", __func__, ep->xid, f_ctl,
e182d682 231 se_cmd->t_data_sg, se_cmd->t_data_nents);
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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);
3699d92a 238
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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 }
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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 /*
05d1c7c0 267 * Setup to use first mem list entry, unless no data.
3699d92a 268 */
ec98f782 269 BUG_ON(frame_len && !se_cmd->t_data_sg);
05d1c7c0 270 if (frame_len) {
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271 sg = se_cmd->t_data_sg;
272 mem_len = sg->length;
273 mem_off = sg->offset;
274 page = sg_page(sg);
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275 }
276
277 while (frame_len) {
278 if (!mem_len) {
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279 sg = sg_next(sg);
280 mem_len = sg->length;
281 mem_off = sg->offset;
282 page = sg_page(sg);
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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
ca747d61 295 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
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AG
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);
ca747d61 301 kunmap_atomic(page_addr);
05d1c7c0 302
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303 from += tlen;
304 frame_len -= tlen;
305 mem_off += tlen;
306 mem_len -= tlen;
307 cmd->write_data_len += tlen;
308 }
309last_frame:
310 if (cmd->write_data_len == se_cmd->data_length)
311 transport_generic_handle_data(se_cmd);
312drop:
313 fc_frame_free(fp);
314}
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315
316/*
317 * Handle and cleanup any HW specific resources if
318 * received ABORTS, errors, timeouts.
319 */
320void 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}
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