target: Updates from AGrover and HCH (round 3)
[linux-3.10.git] / drivers / target / tcm_fc / tfc_io.c
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 <linux/version.h>
32 #include <generated/utsrelease.h>
33 #include <linux/utsname.h>
34 #include <linux/init.h>
35 #include <linux/slab.h>
36 #include <linux/kthread.h>
37 #include <linux/types.h>
38 #include <linux/string.h>
39 #include <linux/configfs.h>
40 #include <linux/ctype.h>
41 #include <linux/hash.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/target_core_base.h>
57 #include <target/configfs_macros.h>
58
59 #include "tcm_fc.h"
60
61 /*
62  * Deliver read data back to initiator.
63  * XXX TBD handle resource problems later.
64  */
65 int ft_queue_data_in(struct se_cmd *se_cmd)
66 {
67         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
68         struct fc_frame *fp = NULL;
69         struct fc_exch *ep;
70         struct fc_lport *lport;
71         struct se_mem *mem;
72         size_t remaining;
73         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
74         u32 mem_off;
75         u32 fh_off = 0;
76         u32 frame_off = 0;
77         size_t frame_len = 0;
78         size_t mem_len;
79         size_t tlen;
80         size_t off_in_page;
81         struct page *page;
82         int use_sg;
83         int error;
84         void *page_addr;
85         void *from;
86         void *to = NULL;
87
88         ep = fc_seq_exch(cmd->seq);
89         lport = ep->lp;
90         cmd->seq = lport->tt.seq_start_next(cmd->seq);
91
92         remaining = se_cmd->data_length;
93
94         /*
95          * Setup to use first mem list entry if any.
96          */
97         if (se_cmd->t_tasks_se_num) {
98                 mem = list_first_entry(&se_cmd->t_mem_list,
99                          struct se_mem, se_list);
100                 mem_len = mem->se_len;
101                 mem_off = mem->se_off;
102                 page = mem->se_page;
103         } else {
104                 mem = NULL;
105                 mem_len = remaining;
106                 mem_off = 0;
107                 page = NULL;
108         }
109
110         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
111         use_sg = !(remaining % 4);
112
113         while (remaining) {
114                 if (!mem_len) {
115                         BUG_ON(!mem);
116                         mem = list_entry(mem->se_list.next,
117                                 struct se_mem, se_list);
118                         mem_len = min((size_t)mem->se_len, remaining);
119                         mem_off = mem->se_off;
120                         page = mem->se_page;
121                 }
122                 if (!frame_len) {
123                         /*
124                          * If lport's has capability of Large Send Offload LSO)
125                          * , then allow 'frame_len' to be as big as 'lso_max'
126                          * if indicated transfer length is >= lport->lso_max
127                          */
128                         frame_len = (lport->seq_offload) ? lport->lso_max :
129                                                           cmd->sess->max_frame;
130                         frame_len = min(frame_len, remaining);
131                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
132                         if (!fp)
133                                 return -ENOMEM;
134                         to = fc_frame_payload_get(fp, 0);
135                         fh_off = frame_off;
136                         frame_off += frame_len;
137                         /*
138                          * Setup the frame's max payload which is used by base
139                          * driver to indicate HW about max frame size, so that
140                          * HW can do fragmentation appropriately based on
141                          * "gso_max_size" of underline netdev.
142                          */
143                         fr_max_payload(fp) = cmd->sess->max_frame;
144                 }
145                 tlen = min(mem_len, frame_len);
146
147                 if (use_sg) {
148                         if (!mem) {
149                                 BUG_ON(!se_cmd->t_task_buf);
150                                 page_addr = se_cmd->t_task_buf + mem_off;
151                                 /*
152                                  * In this case, offset is 'offset_in_page' of
153                                  * (t_task_buf + mem_off) instead of 'mem_off'.
154                                  */
155                                 off_in_page = offset_in_page(page_addr);
156                                 page = virt_to_page(page_addr);
157                                 tlen = min(tlen, PAGE_SIZE - off_in_page);
158                         } else
159                                 off_in_page = mem_off;
160                         BUG_ON(!page);
161                         get_page(page);
162                         skb_fill_page_desc(fp_skb(fp),
163                                            skb_shinfo(fp_skb(fp))->nr_frags,
164                                            page, off_in_page, tlen);
165                         fr_len(fp) += tlen;
166                         fp_skb(fp)->data_len += tlen;
167                         fp_skb(fp)->truesize +=
168                                         PAGE_SIZE << compound_order(page);
169                 } else if (mem) {
170                         BUG_ON(!page);
171                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
172                                            KM_SOFTIRQ0);
173                         page_addr = from;
174                         from += mem_off & ~PAGE_MASK;
175                         tlen = min(tlen, (size_t)(PAGE_SIZE -
176                                                 (mem_off & ~PAGE_MASK)));
177                         memcpy(to, from, tlen);
178                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
179                         to += tlen;
180                 } else {
181                         from = se_cmd->t_task_buf + mem_off;
182                         memcpy(to, from, tlen);
183                         to += tlen;
184                 }
185
186                 mem_off += tlen;
187                 mem_len -= tlen;
188                 frame_len -= tlen;
189                 remaining -= tlen;
190
191                 if (frame_len &&
192                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
193                         continue;
194                 if (!remaining)
195                         f_ctl |= FC_FC_END_SEQ;
196                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
197                                FC_TYPE_FCP, f_ctl, fh_off);
198                 error = lport->tt.seq_send(lport, cmd->seq, fp);
199                 if (error) {
200                         /* XXX For now, initiator will retry */
201                         if (printk_ratelimit())
202                                 printk(KERN_ERR "%s: Failed to send frame %p, "
203                                                 "xid <0x%x>, remaining %zu, "
204                                                 "lso_max <0x%x>\n",
205                                                 __func__, fp, ep->xid,
206                                                 remaining, lport->lso_max);
207                 }
208         }
209         return ft_queue_status(se_cmd);
210 }
211
212 /*
213  * Receive write data frame.
214  */
215 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
216 {
217         struct se_cmd *se_cmd = &cmd->se_cmd;
218         struct fc_seq *seq = cmd->seq;
219         struct fc_exch *ep;
220         struct fc_lport *lport;
221         struct fc_frame_header *fh;
222         struct se_mem *mem;
223         u32 mem_off;
224         u32 rel_off;
225         size_t frame_len;
226         size_t mem_len;
227         size_t tlen;
228         struct page *page;
229         void *page_addr;
230         void *from;
231         void *to;
232         u32 f_ctl;
233         void *buf;
234
235         fh = fc_frame_header_get(fp);
236         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
237                 goto drop;
238
239         /*
240          * Doesn't expect even single byte of payload. Payload
241          * is expected to be copied directly to user buffers
242          * due to DDP (Large Rx offload) feature, hence
243          * BUG_ON if BUF is non-NULL
244          */
245         buf = fc_frame_payload_get(fp, 1);
246         if (cmd->was_ddp_setup && buf) {
247                 printk(KERN_INFO "%s: When DDP was setup, not expected to"
248                                  "receive frame with payload, Payload shall be"
249                                  "copied directly to buffer instead of coming "
250                                  "via. legacy receive queues\n", __func__);
251                 BUG_ON(buf);
252         }
253
254         /*
255          * If ft_cmd indicated 'ddp_setup', in that case only the last frame
256          * should come with 'TSI bit being set'. If 'TSI bit is not set and if
257          * data frame appears here, means error condition. In both the cases
258          * release the DDP context (ddp_put) and in error case, as well
259          * initiate error recovery mechanism.
260          */
261         ep = fc_seq_exch(seq);
262         if (cmd->was_ddp_setup) {
263                 BUG_ON(!ep);
264                 lport = ep->lp;
265                 BUG_ON(!lport);
266         }
267         if (cmd->was_ddp_setup && ep->xid != FC_XID_UNKNOWN) {
268                 f_ctl = ntoh24(fh->fh_f_ctl);
269                 /*
270                  * If TSI bit set in f_ctl, means last write data frame is
271                  * received successfully where payload is posted directly
272                  * to user buffer and only the last frame's header is posted
273                  * in legacy receive queue
274                  */
275                 if (f_ctl & FC_FC_SEQ_INIT) { /* TSI bit set in FC frame */
276                         cmd->write_data_len = lport->tt.ddp_done(lport,
277                                                                 ep->xid);
278                         goto last_frame;
279                 } else {
280                         /*
281                          * Updating the write_data_len may be meaningless at
282                          * this point, but just in case if required in future
283                          * for debugging or any other purpose
284                          */
285                         printk(KERN_ERR "%s: Received frame with TSI bit not"
286                                         " being SET, dropping the frame, "
287                                         "cmd->sg <%p>, cmd->sg_cnt <0x%x>\n",
288                                         __func__, cmd->sg, cmd->sg_cnt);
289                         cmd->write_data_len = lport->tt.ddp_done(lport,
290                                                               ep->xid);
291                         lport->tt.seq_exch_abort(cmd->seq, 0);
292                         goto drop;
293                 }
294         }
295
296         rel_off = ntohl(fh->fh_parm_offset);
297         frame_len = fr_len(fp);
298         if (frame_len <= sizeof(*fh))
299                 goto drop;
300         frame_len -= sizeof(*fh);
301         from = fc_frame_payload_get(fp, 0);
302         if (rel_off >= se_cmd->data_length)
303                 goto drop;
304         if (frame_len + rel_off > se_cmd->data_length)
305                 frame_len = se_cmd->data_length - rel_off;
306
307         /*
308          * Setup to use first mem list entry if any.
309          */
310         if (se_cmd->t_tasks_se_num) {
311                 mem = list_first_entry(&se_cmd->t_mem_list,
312                                        struct se_mem, se_list);
313                 mem_len = mem->se_len;
314                 mem_off = mem->se_off;
315                 page = mem->se_page;
316         } else {
317                 mem = NULL;
318                 page = NULL;
319                 mem_off = 0;
320                 mem_len = frame_len;
321         }
322
323         while (frame_len) {
324                 if (!mem_len) {
325                         BUG_ON(!mem);
326                         mem = list_entry(mem->se_list.next,
327                                          struct se_mem, se_list);
328                         mem_len = mem->se_len;
329                         mem_off = mem->se_off;
330                         page = mem->se_page;
331                 }
332                 if (rel_off >= mem_len) {
333                         rel_off -= mem_len;
334                         mem_len = 0;
335                         continue;
336                 }
337                 mem_off += rel_off;
338                 mem_len -= rel_off;
339                 rel_off = 0;
340
341                 tlen = min(mem_len, frame_len);
342
343                 if (mem) {
344                         to = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
345                                          KM_SOFTIRQ0);
346                         page_addr = to;
347                         to += mem_off & ~PAGE_MASK;
348                         tlen = min(tlen, (size_t)(PAGE_SIZE -
349                                                 (mem_off & ~PAGE_MASK)));
350                         memcpy(to, from, tlen);
351                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
352                 } else {
353                         to = se_cmd->t_task_buf + mem_off;
354                         memcpy(to, from, tlen);
355                 }
356                 from += tlen;
357                 frame_len -= tlen;
358                 mem_off += tlen;
359                 mem_len -= tlen;
360                 cmd->write_data_len += tlen;
361         }
362 last_frame:
363         if (cmd->write_data_len == se_cmd->data_length)
364                 transport_generic_handle_data(se_cmd);
365 drop:
366         fc_frame_free(fp);
367 }