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/scsi.h>
  43 #include <scsi/scsi_host.h>
  44 #include <scsi/scsi_device.h>
  45 #include <scsi/scsi_cmnd.h>
  46 #include <scsi/libfc.h>
  47 #include <scsi/fc_encode.h>
  48
  49 #include <target/target_core_base.h>
  50 #include <target/target_core_fabric.h>
  51 #include <target/target_core_configfs.h>
  52 #include <target/configfs_macros.h>
  53
  54 #include "tcm_fc.h"
  55
  56 /*
  57  * Deliver read data back to initiator.
  58  * XXX TBD handle resource problems later.
  59  */
  60 int ft_queue_data_in(struct se_cmd *se_cmd)
  61 {
  62         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  63         struct fc_frame *fp = NULL;
  64         struct fc_exch *ep;
  65         struct fc_lport *lport;
  66         struct scatterlist *sg = NULL;
  67         size_t remaining;
  68         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  69         u32 mem_off = 0;
  70         u32 fh_off = 0;
  71         u32 frame_off = 0;
  72         size_t frame_len = 0;
  73         size_t mem_len = 0;
  74         size_t tlen;
  75         size_t off_in_page;
  76         struct page *page = NULL;
  77         int use_sg;
  78         int error;
  79         void *page_addr;
  80         void *from;
  81         void *to = NULL;
  82
  83         if (cmd->aborted)
  84                 return 0;
  85
  86         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  87                 goto queue_status;
  88
  89         ep = fc_seq_exch(cmd->seq);
  90         lport = ep->lp;
  91         cmd->seq = lport->tt.seq_start_next(cmd->seq);
  92
  93         remaining = se_cmd->data_length;
  94
  95         /*
  96          * Setup to use first mem list entry, unless no data.
  97          */
  98         BUG_ON(remaining && !se_cmd->t_data_sg);
  99         if (remaining) {
 100                 sg = se_cmd->t_data_sg;
 101                 mem_len = sg->length;
 102                 mem_off = sg->offset;
 103                 page = sg_page(sg);
 104         }
 105
 106         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 107         use_sg = !(remaining % 4);
 108
 109         while (remaining) {
 110                 struct fc_seq *seq = cmd->seq;
 111
 112                 if (!seq) {
 113                         pr_debug("%s: Command aborted, xid 0x%x\n",
 114                                  __func__, ep->xid);
 115                         break;
 116                 }
 117                 if (!mem_len) {
 118                         sg = sg_next(sg);
 119                         mem_len = min((size_t)sg->length, remaining);
 120                         mem_off = sg->offset;
 121                         page = sg_page(sg);
 122                 }
 123                 if (!frame_len) {
 124                         /*
 125                          * If lport's has capability of Large Send Offload LSO)
 126                          * , then allow 'frame_len' to be as big as 'lso_max'
 127                          * if indicated transfer length is >= lport->lso_max
 128                          */
 129                         frame_len = (lport->seq_offload) ? lport->lso_max :
 130                                                           cmd->sess->max_frame;
 131                         frame_len = min(frame_len, remaining);
 132                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 133                         if (!fp)
 134                                 return -ENOMEM;
 135                         to = fc_frame_payload_get(fp, 0);
 136                         fh_off = frame_off;
 137                         frame_off += frame_len;
 138                         /*
 139                          * Setup the frame's max payload which is used by base
 140                          * driver to indicate HW about max frame size, so that
 141                          * HW can do fragmentation appropriately based on
 142                          * "gso_max_size" of underline netdev.
 143                          */
 144                         fr_max_payload(fp) = cmd->sess->max_frame;
 145                 }
 146                 tlen = min(mem_len, frame_len);
 147
 148                 if (use_sg) {
 149                         off_in_page = mem_off;
 150                         BUG_ON(!page);
 151                         get_page(page);
 152                         skb_fill_page_desc(fp_skb(fp),
 153                                            skb_shinfo(fp_skb(fp))->nr_frags,
 154                                            page, off_in_page, tlen);
 155                         fr_len(fp) += tlen;
 156                         fp_skb(fp)->data_len += tlen;
 157                         fp_skb(fp)->truesize +=
 158                                         PAGE_SIZE << compound_order(page);
 159                 } else {
 160                         BUG_ON(!page);
 161                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 162                         page_addr = from;
 163                         from += mem_off & ~PAGE_MASK;
 164                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 165                                                 (mem_off & ~PAGE_MASK)));
 166                         memcpy(to, from, tlen);
 167                         kunmap_atomic(page_addr);
 168                         to += tlen;
 169                 }
 170
 171                 mem_off += tlen;
 172                 mem_len -= tlen;
 173                 frame_len -= tlen;
 174                 remaining -= tlen;
 175
 176                 if (frame_len &&
 177                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 178                         continue;
 179                 if (!remaining)
 180                         f_ctl |= FC_FC_END_SEQ;
 181                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 182                                FC_TYPE_FCP, f_ctl, fh_off);
 183                 error = lport->tt.seq_send(lport, seq, fp);
 184                 if (error) {
 185                         pr_info_ratelimited("%s: Failed to send frame %p, "
 186                                                 "xid <0x%x>, remaining %zu, "
 187                                                 "lso_max <0x%x>\n",
 188                                                 __func__, fp, ep->xid,
 189                                                 remaining, lport->lso_max);
 190                         /*
 191                          * Go ahead and set TASK_SET_FULL status ignoring the
 192                          * rest of the DataIN, and immediately attempt to
 193                          * send the response via ft_queue_status() in order
 194                          * to notify the initiator that it should reduce it's
 195                          * per LUN queue_depth.
 196                          */
 197                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 198                         break;
 199                 }
 200         }
 201 queue_status:
 202         return ft_queue_status(se_cmd);
 203 }
 204
 205 static void ft_execute_work(struct work_struct *work)
 206 {
 207         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 208
 209         target_execute_cmd(&cmd->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 scatterlist *sg = NULL;
 223         u32 mem_off = 0;
 224         u32 rel_off;
 225         size_t frame_len;
 226         size_t mem_len = 0;
 227         size_t tlen;
 228         struct page *page = NULL;
 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         f_ctl = ntoh24(fh->fh_f_ctl);
 240         ep = fc_seq_exch(seq);
 241         lport = ep->lp;
 242         if (cmd->was_ddp_setup) {
 243                 BUG_ON(!ep);
 244                 BUG_ON(!lport);
 245                 /*
 246                  * Since DDP (Large Rx offload) was setup for this request,
 247                  * payload is expected to be copied directly to user buffers.
 248                  */
 249                 buf = fc_frame_payload_get(fp, 1);
 250                 if (buf)
 251                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 252                                 "cmd->sg_cnt 0x%x. DDP was setup"
 253                                 " hence not expected to receive frame with "
 254                                 "payload, Frame will be dropped if"
 255                                 "'Sequence Initiative' bit in f_ctl is"
 256                                 "not set\n", __func__, ep->xid, f_ctl,
 257                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 258                 /*
 259                  * Invalidate HW DDP context if it was setup for respective
 260                  * command. Invalidation of HW DDP context is requited in both
 261                  * situation (success and error).
 262                  */
 263                 ft_invl_hw_context(cmd);
 264
 265                 /*
 266                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 267                  * write data frame is received successfully where payload is
 268                  * posted directly to user buffer and only the last frame's
 269                  * header is posted in receive queue.
 270                  *
 271                  * If "Sequence Initiative (TSI)" bit is not set, means error
 272                  * condition w.r.t. DDP, hence drop the packet and let explict
 273                  * ABORTS from other end of exchange timer trigger the recovery.
 274                  */
 275                 if (f_ctl & FC_FC_SEQ_INIT)
 276                         goto last_frame;
 277                 else
 278                         goto drop;
 279         }
 280
 281         rel_off = ntohl(fh->fh_parm_offset);
 282         frame_len = fr_len(fp);
 283         if (frame_len <= sizeof(*fh))
 284                 goto drop;
 285         frame_len -= sizeof(*fh);
 286         from = fc_frame_payload_get(fp, 0);
 287         if (rel_off >= se_cmd->data_length)
 288                 goto drop;
 289         if (frame_len + rel_off > se_cmd->data_length)
 290                 frame_len = se_cmd->data_length - rel_off;
 291
 292         /*
 293          * Setup to use first mem list entry, unless no data.
 294          */
 295         BUG_ON(frame_len && !se_cmd->t_data_sg);
 296         if (frame_len) {
 297                 sg = se_cmd->t_data_sg;
 298                 mem_len = sg->length;
 299                 mem_off = sg->offset;
 300                 page = sg_page(sg);
 301         }
 302
 303         while (frame_len) {
 304                 if (!mem_len) {
 305                         sg = sg_next(sg);
 306                         mem_len = sg->length;
 307                         mem_off = sg->offset;
 308                         page = sg_page(sg);
 309                 }
 310                 if (rel_off >= mem_len) {
 311                         rel_off -= mem_len;
 312                         mem_len = 0;
 313                         continue;
 314                 }
 315                 mem_off += rel_off;
 316                 mem_len -= rel_off;
 317                 rel_off = 0;
 318
 319                 tlen = min(mem_len, frame_len);
 320
 321                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 322                 page_addr = to;
 323                 to += mem_off & ~PAGE_MASK;
 324                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 325                                           (mem_off & ~PAGE_MASK)));
 326                 memcpy(to, from, tlen);
 327                 kunmap_atomic(page_addr);
 328
 329                 from += tlen;
 330                 frame_len -= tlen;
 331                 mem_off += tlen;
 332                 mem_len -= tlen;
 333                 cmd->write_data_len += tlen;
 334         }
 335 last_frame:
 336         if (cmd->write_data_len == se_cmd->data_length) {
 337                 INIT_WORK(&cmd->work, ft_execute_work);
 338                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 339         }
 340 drop:
 341         fc_frame_free(fp);
 342 }
 343
 344 /*
 345  * Handle and cleanup any HW specific resources if
 346  * received ABORTS, errors, timeouts.
 347  */
 348 void ft_invl_hw_context(struct ft_cmd *cmd)
 349 {
 350         struct fc_seq *seq;
 351         struct fc_exch *ep = NULL;
 352         struct fc_lport *lport = NULL;
 353
 354         BUG_ON(!cmd);
 355         seq = cmd->seq;
 356
 357         /* Cleanup the DDP context in HW if DDP was setup */
 358         if (cmd->was_ddp_setup && seq) {
 359                 ep = fc_seq_exch(seq);
 360                 if (ep) {
 361                         lport = ep->lp;
 362                         if (lport && (ep->xid <= lport->lro_xid)) {
 363                                 /*
 364                                  * "ddp_done" trigger invalidation of HW
 365                                  * specific DDP context
 366                                  */
 367                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 368                                                                       ep->xid);
 369
 370                                 /*
 371                                  * Resetting same variable to indicate HW's
 372                                  * DDP context has been invalidated to avoid
 373                                  * re_invalidation of same context (context is
 374                                  * identified using ep->xid)
 375                                  */
 376                                 cmd->was_ddp_setup = 0;
 377                         }
 378                 }
 379         }
 380 }