kernel/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/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>
  44
  45 #include <target/target_core_base.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "tcm_fc.h"
  49
  50 /*
  51  * Deliver read data back to initiator.
  52  * XXX TBD handle resource problems later.
  53  */
  54 int ft_queue_data_in(struct se_cmd *se_cmd)
  55 {
  56         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  57         struct fc_frame *fp = NULL;
  58         struct fc_exch *ep;
  59         struct fc_lport *lport;
  60         struct scatterlist *sg = NULL;
  61         size_t remaining;
  62         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  63         u32 mem_off = 0;
  64         u32 fh_off = 0;
  65         u32 frame_off = 0;
  66         size_t frame_len = 0;
  67         size_t mem_len = 0;
  68         size_t tlen;
  69         size_t off_in_page;
  70         struct page *page = NULL;
  71         int use_sg;
  72         int error;
  73         void *page_addr;
  74         void *from;
  75         void *to = NULL;
  76
  77         if (cmd->aborted)
  78                 return 0;
  79
  80         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  81                 goto queue_status;
  82
  83         ep = fc_seq_exch(cmd->seq);
  84         lport = ep->lp;
  85         cmd->seq = lport->tt.seq_start_next(cmd->seq);
  86
  87         remaining = se_cmd->data_length;
  88
  89         /*
  90          * Setup to use first mem list entry, unless no data.
  91          */
  92         BUG_ON(remaining && !se_cmd->t_data_sg);
  93         if (remaining) {
  94                 sg = se_cmd->t_data_sg;
  95                 mem_len = sg->length;
  96                 mem_off = sg->offset;
  97                 page = sg_page(sg);
  98         }
  99
 100         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 101         use_sg = !(remaining % 4);
 102
 103         while (remaining) {
 104                 struct fc_seq *seq = cmd->seq;
 105
 106                 if (!seq) {
 107                         pr_debug("%s: Command aborted, xid 0x%x\n",
 108                                  __func__, ep->xid);
 109                         break;
 110                 }
 111                 if (!mem_len) {
 112                         sg = sg_next(sg);
 113                         mem_len = min((size_t)sg->length, remaining);
 114                         mem_off = sg->offset;
 115                         page = sg_page(sg);
 116                 }
 117                 if (!frame_len) {
 118                         /*
 119                          * If lport's has capability of Large Send Offload LSO)
 120                          * , then allow 'frame_len' to be as big as 'lso_max'
 121                          * if indicated transfer length is >= lport->lso_max
 122                          */
 123                         frame_len = (lport->seq_offload) ? lport->lso_max :
 124                                                           cmd->sess->max_frame;
 125                         frame_len = min(frame_len, remaining);
 126                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 127                         if (!fp)
 128                                 return -ENOMEM;
 129                         to = fc_frame_payload_get(fp, 0);
 130                         fh_off = frame_off;
 131                         frame_off += frame_len;
 132                         /*
 133                          * Setup the frame's max payload which is used by base
 134                          * driver to indicate HW about max frame size, so that
 135                          * HW can do fragmentation appropriately based on
 136                          * "gso_max_size" of underline netdev.
 137                          */
 138                         fr_max_payload(fp) = cmd->sess->max_frame;
 139                 }
 140                 tlen = min(mem_len, frame_len);
 141
 142                 if (use_sg) {
 143                         off_in_page = mem_off;
 144                         BUG_ON(!page);
 145                         get_page(page);
 146                         skb_fill_page_desc(fp_skb(fp),
 147                                            skb_shinfo(fp_skb(fp))->nr_frags,
 148                                            page, off_in_page, tlen);
 149                         fr_len(fp) += tlen;
 150                         fp_skb(fp)->data_len += tlen;
 151                         fp_skb(fp)->truesize +=
 152                                         PAGE_SIZE << compound_order(page);
 153                 } else {
 154                         BUG_ON(!page);
 155                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 156                         page_addr = from;
 157                         from += mem_off & ~PAGE_MASK;
 158                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 159                                                 (mem_off & ~PAGE_MASK)));
 160                         memcpy(to, from, tlen);
 161                         kunmap_atomic(page_addr);
 162                         to += tlen;
 163                 }
 164
 165                 mem_off += tlen;
 166                 mem_len -= tlen;
 167                 frame_len -= tlen;
 168                 remaining -= tlen;
 169
 170                 if (frame_len &&
 171                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 172                         continue;
 173                 if (!remaining)
 174                         f_ctl |= FC_FC_END_SEQ;
 175                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 176                                FC_TYPE_FCP, f_ctl, fh_off);
 177                 error = lport->tt.seq_send(lport, seq, fp);
 178                 if (error) {
 179                         pr_info_ratelimited("%s: Failed to send frame %p, "
 180                                                 "xid <0x%x>, remaining %zu, "
 181                                                 "lso_max <0x%x>\n",
 182                                                 __func__, fp, ep->xid,
 183                                                 remaining, lport->lso_max);
 184                         /*
 185                          * Go ahead and set TASK_SET_FULL status ignoring the
 186                          * rest of the DataIN, and immediately attempt to
 187                          * send the response via ft_queue_status() in order
 188                          * to notify the initiator that it should reduce it's
 189                          * per LUN queue_depth.
 190                          */
 191                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 192                         break;
 193                 }
 194         }
 195 queue_status:
 196         return ft_queue_status(se_cmd);
 197 }
 198
 199 static void ft_execute_work(struct work_struct *work)
 200 {
 201         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 202
 203         target_execute_cmd(&cmd->se_cmd);
 204 }
 205
 206 /*
 207  * Receive write data frame.
 208  */
 209 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 210 {
 211         struct se_cmd *se_cmd = &cmd->se_cmd;
 212         struct fc_seq *seq = cmd->seq;
 213         struct fc_exch *ep;
 214         struct fc_lport *lport;
 215         struct fc_frame_header *fh;
 216         struct scatterlist *sg = NULL;
 217         u32 mem_off = 0;
 218         u32 rel_off;
 219         size_t frame_len;
 220         size_t mem_len = 0;
 221         size_t tlen;
 222         struct page *page = NULL;
 223         void *page_addr;
 224         void *from;
 225         void *to;
 226         u32 f_ctl;
 227         void *buf;
 228
 229         fh = fc_frame_header_get(fp);
 230         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 231                 goto drop;
 232
 233         f_ctl = ntoh24(fh->fh_f_ctl);
 234         ep = fc_seq_exch(seq);
 235         lport = ep->lp;
 236         if (cmd->was_ddp_setup) {
 237                 BUG_ON(!ep);
 238                 BUG_ON(!lport);
 239                 /*
 240                  * Since DDP (Large Rx offload) was setup for this request,
 241                  * payload is expected to be copied directly to user buffers.
 242                  */
 243                 buf = fc_frame_payload_get(fp, 1);
 244                 if (buf)
 245                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 246                                 "cmd->sg_cnt 0x%x. DDP was setup"
 247                                 " hence not expected to receive frame with "
 248                                 "payload, Frame will be dropped if"
 249                                 "'Sequence Initiative' bit in f_ctl is"
 250                                 "not set\n", __func__, ep->xid, f_ctl,
 251                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 252                 /*
 253                  * Invalidate HW DDP context if it was setup for respective
 254                  * command. Invalidation of HW DDP context is requited in both
 255                  * situation (success and error).
 256                  */
 257                 ft_invl_hw_context(cmd);
 258
 259                 /*
 260                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 261                  * write data frame is received successfully where payload is
 262                  * posted directly to user buffer and only the last frame's
 263                  * header is posted in receive queue.
 264                  *
 265                  * If "Sequence Initiative (TSI)" bit is not set, means error
 266                  * condition w.r.t. DDP, hence drop the packet and let explict
 267                  * ABORTS from other end of exchange timer trigger the recovery.
 268                  */
 269                 if (f_ctl & FC_FC_SEQ_INIT)
 270                         goto last_frame;
 271                 else
 272                         goto drop;
 273         }
 274
 275         rel_off = ntohl(fh->fh_parm_offset);
 276         frame_len = fr_len(fp);
 277         if (frame_len <= sizeof(*fh))
 278                 goto drop;
 279         frame_len -= sizeof(*fh);
 280         from = fc_frame_payload_get(fp, 0);
 281         if (rel_off >= se_cmd->data_length)
 282                 goto drop;
 283         if (frame_len + rel_off > se_cmd->data_length)
 284                 frame_len = se_cmd->data_length - rel_off;
 285
 286         /*
 287          * Setup to use first mem list entry, unless no data.
 288          */
 289         BUG_ON(frame_len && !se_cmd->t_data_sg);
 290         if (frame_len) {
 291                 sg = se_cmd->t_data_sg;
 292                 mem_len = sg->length;
 293                 mem_off = sg->offset;
 294                 page = sg_page(sg);
 295         }
 296
 297         while (frame_len) {
 298                 if (!mem_len) {
 299                         sg = sg_next(sg);
 300                         mem_len = sg->length;
 301                         mem_off = sg->offset;
 302                         page = sg_page(sg);
 303                 }
 304                 if (rel_off >= mem_len) {
 305                         rel_off -= mem_len;
 306                         mem_len = 0;
 307                         continue;
 308                 }
 309                 mem_off += rel_off;
 310                 mem_len -= rel_off;
 311                 rel_off = 0;
 312
 313                 tlen = min(mem_len, frame_len);
 314
 315                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 316                 page_addr = to;
 317                 to += mem_off & ~PAGE_MASK;
 318                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 319                                           (mem_off & ~PAGE_MASK)));
 320                 memcpy(to, from, tlen);
 321                 kunmap_atomic(page_addr);
 322
 323                 from += tlen;
 324                 frame_len -= tlen;
 325                 mem_off += tlen;
 326                 mem_len -= tlen;
 327                 cmd->write_data_len += tlen;
 328         }
 329 last_frame:
 330         if (cmd->write_data_len == se_cmd->data_length) {
 331                 INIT_WORK(&cmd->work, ft_execute_work);
 332                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 333         }
 334 drop:
 335         fc_frame_free(fp);
 336 }
 337
 338 /*
 339  * Handle and cleanup any HW specific resources if
 340  * received ABORTS, errors, timeouts.
 341  */
 342 void ft_invl_hw_context(struct ft_cmd *cmd)
 343 {
 344         struct fc_seq *seq;
 345         struct fc_exch *ep = NULL;
 346         struct fc_lport *lport = NULL;
 347
 348         BUG_ON(!cmd);
 349         seq = cmd->seq;
 350
 351         /* Cleanup the DDP context in HW if DDP was setup */
 352         if (cmd->was_ddp_setup && seq) {
 353                 ep = fc_seq_exch(seq);
 354                 if (ep) {
 355                         lport = ep->lp;
 356                         if (lport && (ep->xid <= lport->lro_xid)) {
 357                                 /*
 358                                  * "ddp_done" trigger invalidation of HW
 359                                  * specific DDP context
 360                                  */
 361                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 362                                                                       ep->xid);
 363
 364                                 /*
 365                                  * Resetting same variable to indicate HW's
 366                                  * DDP context has been invalidated to avoid
 367                                  * re_invalidation of same context (context is
 368                                  * identified using ep->xid)
 369                                  */
 370                                 cmd->was_ddp_setup = 0;
 371                         }
 372                 }
 373         }
 374 }