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/configfs_macros.h>
  52
  53 #include "tcm_fc.h"
  54
  55 /*
  56  * Deliver read data back to initiator.
  57  * XXX TBD handle resource problems later.
  58  */
  59 int ft_queue_data_in(struct se_cmd *se_cmd)
  60 {
  61         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  62         struct fc_frame *fp = NULL;
  63         struct fc_exch *ep;
  64         struct fc_lport *lport;
  65         struct scatterlist *sg = NULL;
  66         size_t remaining;
  67         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  68         u32 mem_off = 0;
  69         u32 fh_off = 0;
  70         u32 frame_off = 0;
  71         size_t frame_len = 0;
  72         size_t mem_len = 0;
  73         size_t tlen;
  74         size_t off_in_page;
  75         struct page *page = NULL;
  76         int use_sg;
  77         int error;
  78         void *page_addr;
  79         void *from;
  80         void *to = NULL;
  81
  82         if (cmd->aborted)
  83                 return 0;
  84
  85         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  86                 goto queue_status;
  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, unless no data.
  96          */
  97         BUG_ON(remaining && !se_cmd->t_data_sg);
  98         if (remaining) {
  99                 sg = se_cmd->t_data_sg;
 100                 mem_len = sg->length;
 101                 mem_off = sg->offset;
 102                 page = sg_page(sg);
 103         }
 104
 105         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 106         use_sg = !(remaining % 4);
 107
 108         while (remaining) {
 109                 struct fc_seq *seq = cmd->seq;
 110
 111                 if (!seq) {
 112                         pr_debug("%s: Command aborted, xid 0x%x\n",
 113                                  __func__, ep->xid);
 114                         break;
 115                 }
 116                 if (!mem_len) {
 117                         sg = sg_next(sg);
 118                         mem_len = min((size_t)sg->length, remaining);
 119                         mem_off = sg->offset;
 120                         page = sg_page(sg);
 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                         off_in_page = mem_off;
 149                         BUG_ON(!page);
 150                         get_page(page);
 151                         skb_fill_page_desc(fp_skb(fp),
 152                                            skb_shinfo(fp_skb(fp))->nr_frags,
 153                                            page, off_in_page, tlen);
 154                         fr_len(fp) += tlen;
 155                         fp_skb(fp)->data_len += tlen;
 156                         fp_skb(fp)->truesize +=
 157                                         PAGE_SIZE << compound_order(page);
 158                 } else {
 159                         BUG_ON(!page);
 160                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 161                         page_addr = from;
 162                         from += mem_off & ~PAGE_MASK;
 163                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 164                                                 (mem_off & ~PAGE_MASK)));
 165                         memcpy(to, from, tlen);
 166                         kunmap_atomic(page_addr);
 167                         to += tlen;
 168                 }
 169
 170                 mem_off += tlen;
 171                 mem_len -= tlen;
 172                 frame_len -= tlen;
 173                 remaining -= tlen;
 174
 175                 if (frame_len &&
 176                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 177                         continue;
 178                 if (!remaining)
 179                         f_ctl |= FC_FC_END_SEQ;
 180                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 181                                FC_TYPE_FCP, f_ctl, fh_off);
 182                 error = lport->tt.seq_send(lport, seq, fp);
 183                 if (error) {
 184                         pr_info_ratelimited("%s: Failed to send frame %p, "
 185                                                 "xid <0x%x>, remaining %zu, "
 186                                                 "lso_max <0x%x>\n",
 187                                                 __func__, fp, ep->xid,
 188                                                 remaining, lport->lso_max);
 189                         /*
 190                          * Go ahead and set TASK_SET_FULL status ignoring the
 191                          * rest of the DataIN, and immediately attempt to
 192                          * send the response via ft_queue_status() in order
 193                          * to notify the initiator that it should reduce it's
 194                          * per LUN queue_depth.
 195                          */
 196                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 197                         break;
 198                 }
 199         }
 200 queue_status:
 201         return ft_queue_status(se_cmd);
 202 }
 203
 204 static void ft_execute_work(struct work_struct *work)
 205 {
 206         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 207
 208         target_execute_cmd(&cmd->se_cmd);
 209 }
 210
 211 /*
 212  * Receive write data frame.
 213  */
 214 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 215 {
 216         struct se_cmd *se_cmd = &cmd->se_cmd;
 217         struct fc_seq *seq = cmd->seq;
 218         struct fc_exch *ep;
 219         struct fc_lport *lport;
 220         struct fc_frame_header *fh;
 221         struct scatterlist *sg = NULL;
 222         u32 mem_off = 0;
 223         u32 rel_off;
 224         size_t frame_len;
 225         size_t mem_len = 0;
 226         size_t tlen;
 227         struct page *page = NULL;
 228         void *page_addr;
 229         void *from;
 230         void *to;
 231         u32 f_ctl;
 232         void *buf;
 233
 234         fh = fc_frame_header_get(fp);
 235         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 236                 goto drop;
 237
 238         f_ctl = ntoh24(fh->fh_f_ctl);
 239         ep = fc_seq_exch(seq);
 240         lport = ep->lp;
 241         if (cmd->was_ddp_setup) {
 242                 BUG_ON(!ep);
 243                 BUG_ON(!lport);
 244                 /*
 245                  * Since DDP (Large Rx offload) was setup for this request,
 246                  * payload is expected to be copied directly to user buffers.
 247                  */
 248                 buf = fc_frame_payload_get(fp, 1);
 249                 if (buf)
 250                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 251                                 "cmd->sg_cnt 0x%x. DDP was setup"
 252                                 " hence not expected to receive frame with "
 253                                 "payload, Frame will be dropped if"
 254                                 "'Sequence Initiative' bit in f_ctl is"
 255                                 "not set\n", __func__, ep->xid, f_ctl,
 256                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 257                 /*
 258                  * Invalidate HW DDP context if it was setup for respective
 259                  * command. Invalidation of HW DDP context is requited in both
 260                  * situation (success and error).
 261                  */
 262                 ft_invl_hw_context(cmd);
 263
 264                 /*
 265                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 266                  * write data frame is received successfully where payload is
 267                  * posted directly to user buffer and only the last frame's
 268                  * header is posted in receive queue.
 269                  *
 270                  * If "Sequence Initiative (TSI)" bit is not set, means error
 271                  * condition w.r.t. DDP, hence drop the packet and let explict
 272                  * ABORTS from other end of exchange timer trigger the recovery.
 273                  */
 274                 if (f_ctl & FC_FC_SEQ_INIT)
 275                         goto last_frame;
 276                 else
 277                         goto drop;
 278         }
 279
 280         rel_off = ntohl(fh->fh_parm_offset);
 281         frame_len = fr_len(fp);
 282         if (frame_len <= sizeof(*fh))
 283                 goto drop;
 284         frame_len -= sizeof(*fh);
 285         from = fc_frame_payload_get(fp, 0);
 286         if (rel_off >= se_cmd->data_length)
 287                 goto drop;
 288         if (frame_len + rel_off > se_cmd->data_length)
 289                 frame_len = se_cmd->data_length - rel_off;
 290
 291         /*
 292          * Setup to use first mem list entry, unless no data.
 293          */
 294         BUG_ON(frame_len && !se_cmd->t_data_sg);
 295         if (frame_len) {
 296                 sg = se_cmd->t_data_sg;
 297                 mem_len = sg->length;
 298                 mem_off = sg->offset;
 299                 page = sg_page(sg);
 300         }
 301
 302         while (frame_len) {
 303                 if (!mem_len) {
 304                         sg = sg_next(sg);
 305                         mem_len = sg->length;
 306                         mem_off = sg->offset;
 307                         page = sg_page(sg);
 308                 }
 309                 if (rel_off >= mem_len) {
 310                         rel_off -= mem_len;
 311                         mem_len = 0;
 312                         continue;
 313                 }
 314                 mem_off += rel_off;
 315                 mem_len -= rel_off;
 316                 rel_off = 0;
 317
 318                 tlen = min(mem_len, frame_len);
 319
 320                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 321                 page_addr = to;
 322                 to += mem_off & ~PAGE_MASK;
 323                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 324                                           (mem_off & ~PAGE_MASK)));
 325                 memcpy(to, from, tlen);
 326                 kunmap_atomic(page_addr);
 327
 328                 from += tlen;
 329                 frame_len -= tlen;
 330                 mem_off += tlen;
 331                 mem_len -= tlen;
 332                 cmd->write_data_len += tlen;
 333         }
 334 last_frame:
 335         if (cmd->write_data_len == se_cmd->data_length) {
 336                 INIT_WORK(&cmd->work, ft_execute_work);
 337                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 338         }
 339 drop:
 340         fc_frame_free(fp);
 341 }
 342
 343 /*
 344  * Handle and cleanup any HW specific resources if
 345  * received ABORTS, errors, timeouts.
 346  */
 347 void ft_invl_hw_context(struct ft_cmd *cmd)
 348 {
 349         struct fc_seq *seq;
 350         struct fc_exch *ep = NULL;
 351         struct fc_lport *lport = NULL;
 352
 353         BUG_ON(!cmd);
 354         seq = cmd->seq;
 355
 356         /* Cleanup the DDP context in HW if DDP was setup */
 357         if (cmd->was_ddp_setup && seq) {
 358                 ep = fc_seq_exch(seq);
 359                 if (ep) {
 360                         lport = ep->lp;
 361                         if (lport && (ep->xid <= lport->lro_xid)) {
 362                                 /*
 363                                  * "ddp_done" trigger invalidation of HW
 364                                  * specific DDP context
 365                                  */
 366                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 367                                                                       ep->xid);
 368
 369                                 /*
 370                                  * Resetting same variable to indicate HW's
 371                                  * DDP context has been invalidated to avoid
 372                                  * re_invalidation of same context (context is
 373                                  * identified using ep->xid)
 374                                  */
 375                                 cmd->was_ddp_setup = 0;
 376                         }
 377                 }
 378         }
 379 }