drivers/scsi/libfc/fc_fcp.c

   1 /*
   2  * Copyright(c) 2007 Intel Corporation. All rights reserved.
   3  * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
   4  * Copyright(c) 2008 Mike Christie
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Maintained at www.Open-FCoE.org
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/delay.h>
  24 #include <linux/kernel.h>
  25 #include <linux/types.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/scatterlist.h>
  28 #include <linux/err.h>
  29 #include <linux/crc32.h>
  30
  31 #include <scsi/scsi_tcq.h>
  32 #include <scsi/scsi.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi_device.h>
  35 #include <scsi/scsi_cmnd.h>
  36
  37 #include <scsi/fc/fc_fc2.h>
  38
  39 #include <scsi/libfc.h>
  40 #include <scsi/fc_encode.h>
  41
  42 MODULE_AUTHOR("Open-FCoE.org");
  43 MODULE_DESCRIPTION("libfc");
  44 MODULE_LICENSE("GPL");
  45
  46 static int fc_fcp_debug;
  47
  48 #define FC_DEBUG_FCP(fmt...)                    \
  49         do {                                    \
  50                 if (fc_fcp_debug)               \
  51                         FC_DBG(fmt);            \
  52         } while (0)
  53
  54 static struct kmem_cache *scsi_pkt_cachep;
  55
  56 /* SRB state definitions */
  57 #define FC_SRB_FREE             0               /* cmd is free */
  58 #define FC_SRB_CMD_SENT         (1 << 0)        /* cmd has been sent */
  59 #define FC_SRB_RCV_STATUS       (1 << 1)        /* response has arrived */
  60 #define FC_SRB_ABORT_PENDING    (1 << 2)        /* cmd abort sent to device */
  61 #define FC_SRB_ABORTED          (1 << 3)        /* abort acknowleged */
  62 #define FC_SRB_DISCONTIG        (1 << 4)        /* non-sequential data recvd */
  63 #define FC_SRB_COMPL            (1 << 5)        /* fc_io_compl has been run */
  64 #define FC_SRB_FCP_PROCESSING_TMO (1 << 6)      /* timer function processing */
  65 #define FC_SRB_NOMEM            (1 << 7)        /* dropped to out of mem */
  66
  67 #define FC_SRB_READ             (1 << 1)
  68 #define FC_SRB_WRITE            (1 << 0)
  69
  70 /*
  71  * The SCp.ptr should be tested and set under the host lock. NULL indicates
  72  * that the command has been retruned to the scsi layer.
  73  */
  74 #define CMD_SP(Cmnd)                ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
  75 #define CMD_ENTRY_STATUS(Cmnd)      ((Cmnd)->SCp.have_data_in)
  76 #define CMD_COMPL_STATUS(Cmnd)      ((Cmnd)->SCp.this_residual)
  77 #define CMD_SCSI_STATUS(Cmnd)       ((Cmnd)->SCp.Status)
  78 #define CMD_RESID_LEN(Cmnd)         ((Cmnd)->SCp.buffers_residual)
  79
  80 struct fc_fcp_internal {
  81         mempool_t       *scsi_pkt_pool;
  82         struct list_head scsi_pkt_queue;
  83         u8              throttled;
  84 };
  85
  86 #define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
  87
  88 /*
  89  * function prototypes
  90  * FC scsi I/O related functions
  91  */
  92 static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  93 static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  94 static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  95 static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  96 static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  97 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp);
  98 static void fc_timeout_error(struct fc_fcp_pkt *);
  99 static void fc_fcp_timeout(unsigned long data);
 100 static void fc_fcp_rec(struct fc_fcp_pkt *);
 101 static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
 102 static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
 103 static void fc_io_compl(struct fc_fcp_pkt *);
 104
 105 static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
 106 static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
 107 static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
 108
 109 /*
 110  * command status codes
 111  */
 112 #define FC_COMPLETE             0
 113 #define FC_CMD_ABORTED          1
 114 #define FC_CMD_RESET            2
 115 #define FC_CMD_PLOGO            3
 116 #define FC_SNS_RCV              4
 117 #define FC_TRANS_ERR            5
 118 #define FC_DATA_OVRRUN          6
 119 #define FC_DATA_UNDRUN          7
 120 #define FC_ERROR                8
 121 #define FC_HRD_ERROR            9
 122 #define FC_CMD_TIME_OUT         10
 123
 124 /*
 125  * Error recovery timeout values.
 126  */
 127 #define FC_SCSI_ER_TIMEOUT      (10 * HZ)
 128 #define FC_SCSI_TM_TOV          (10 * HZ)
 129 #define FC_SCSI_REC_TOV         (2 * HZ)
 130 #define FC_HOST_RESET_TIMEOUT   (30 * HZ)
 131
 132 #define FC_MAX_ERROR_CNT        5
 133 #define FC_MAX_RECOV_RETRY      3
 134
 135 #define FC_FCP_DFLT_QUEUE_DEPTH 32
 136
 137 /**
 138  * fc_fcp_pkt_alloc - allocation routine for scsi_pkt packet
 139  * @lp:         fc lport struct
 140  * @gfp:        gfp flags for allocation
 141  *
 142  * This is used by upper layer scsi driver.
 143  * Return Value : scsi_pkt structure or null on allocation failure.
 144  * Context      : call from process context. no locking required.
 145  */
 146 static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lp, gfp_t gfp)
 147 {
 148         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 149         struct fc_fcp_pkt *fsp;
 150
 151         fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
 152         if (fsp) {
 153                 memset(fsp, 0, sizeof(*fsp));
 154                 fsp->lp = lp;
 155                 atomic_set(&fsp->ref_cnt, 1);
 156                 init_timer(&fsp->timer);
 157                 INIT_LIST_HEAD(&fsp->list);
 158                 spin_lock_init(&fsp->scsi_pkt_lock);
 159         }
 160         return fsp;
 161 }
 162
 163 /**
 164  * fc_fcp_pkt_release - release hold on scsi_pkt packet
 165  * @fsp:        fcp packet struct
 166  *
 167  * This is used by upper layer scsi driver.
 168  * Context      : call from process  and interrupt context.
 169  *                no locking required
 170  */
 171 static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
 172 {
 173         if (atomic_dec_and_test(&fsp->ref_cnt)) {
 174                 struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 175
 176                 mempool_free(fsp, si->scsi_pkt_pool);
 177         }
 178 }
 179
 180 static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
 181 {
 182         atomic_inc(&fsp->ref_cnt);
 183 }
 184
 185 /**
 186  * fc_fcp_pkt_destory - release hold on scsi_pkt packet
 187  *
 188  * @seq:                exchange sequence
 189  * @fsp:        fcp packet struct
 190  *
 191  * Release hold on scsi_pkt packet set to keep scsi_pkt
 192  * till EM layer exch resource is not freed.
 193  * Context      : called from from EM layer.
 194  *                no locking required
 195  */
 196 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 197 {
 198         fc_fcp_pkt_release(fsp);
 199 }
 200
 201 /**
 202  * fc_fcp_lock_pkt - lock a packet and get a ref to it.
 203  * @fsp:        fcp packet
 204  *
 205  * We should only return error if we return a command to scsi-ml before
 206  * getting a response. This can happen in cases where we send a abort, but
 207  * do not wait for the response and the abort and command can be passing
 208  * each other on the wire/network-layer.
 209  *
 210  * Note: this function locks the packet and gets a reference to allow
 211  * callers to call the completion function while the lock is held and
 212  * not have to worry about the packets refcount.
 213  *
 214  * TODO: Maybe we should just have callers grab/release the lock and
 215  * have a function that they call to verify the fsp and grab a ref if
 216  * needed.
 217  */
 218 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 219 {
 220         spin_lock_bh(&fsp->scsi_pkt_lock);
 221         if (fsp->state & FC_SRB_COMPL) {
 222                 spin_unlock_bh(&fsp->scsi_pkt_lock);
 223                 return -EPERM;
 224         }
 225
 226         fc_fcp_pkt_hold(fsp);
 227         return 0;
 228 }
 229
 230 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 231 {
 232         spin_unlock_bh(&fsp->scsi_pkt_lock);
 233         fc_fcp_pkt_release(fsp);
 234 }
 235
 236 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 237 {
 238         if (!(fsp->state & FC_SRB_COMPL))
 239                 mod_timer(&fsp->timer, jiffies + delay);
 240 }
 241
 242 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 243 {
 244         if (!fsp->seq_ptr)
 245                 return -EINVAL;
 246
 247         fsp->state |= FC_SRB_ABORT_PENDING;
 248         return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
 249 }
 250
 251 /*
 252  * Retry command.
 253  * An abort isn't needed.
 254  */
 255 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
 256 {
 257         if (fsp->seq_ptr) {
 258                 fsp->lp->tt.exch_done(fsp->seq_ptr);
 259                 fsp->seq_ptr = NULL;
 260         }
 261
 262         fsp->state &= ~FC_SRB_ABORT_PENDING;
 263         fsp->io_status = SUGGEST_RETRY << 24;
 264         fsp->status_code = FC_ERROR;
 265         fc_fcp_complete_locked(fsp);
 266 }
 267
 268 /*
 269  * Receive SCSI data from target.
 270  * Called after receiving solicited data.
 271  */
 272 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 273 {
 274         struct scsi_cmnd *sc = fsp->cmd;
 275         struct fc_lport *lp = fsp->lp;
 276         struct fcoe_dev_stats *stats;
 277         struct fc_frame_header *fh;
 278         size_t start_offset;
 279         size_t offset;
 280         u32 crc;
 281         u32 copy_len = 0;
 282         size_t len;
 283         void *buf;
 284         struct scatterlist *sg;
 285         size_t remaining;
 286
 287         fh = fc_frame_header_get(fp);
 288         offset = ntohl(fh->fh_parm_offset);
 289         start_offset = offset;
 290         len = fr_len(fp) - sizeof(*fh);
 291         buf = fc_frame_payload_get(fp, 0);
 292
 293         if (offset + len > fsp->data_len) {
 294                 /*
 295                  * this should never happen
 296                  */
 297                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 298                     fc_frame_crc_check(fp))
 299                         goto crc_err;
 300                 FC_DEBUG_FCP("data received past end. len %zx offset %zx "
 301                              "data_len %x\n", len, offset, fsp->data_len);
 302                 fc_fcp_retry_cmd(fsp);
 303                 return;
 304         }
 305         if (offset != fsp->xfer_len)
 306                 fsp->state |= FC_SRB_DISCONTIG;
 307
 308         crc = 0;
 309         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 310                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 311
 312         sg = scsi_sglist(sc);
 313         remaining = len;
 314
 315         while (remaining > 0 && sg) {
 316                 size_t off;
 317                 void *page_addr;
 318                 size_t sg_bytes;
 319
 320                 if (offset >= sg->length) {
 321                         offset -= sg->length;
 322                         sg = sg_next(sg);
 323                         continue;
 324                 }
 325                 sg_bytes = min(remaining, sg->length - offset);
 326
 327                 /*
 328                  * The scatterlist item may be bigger than PAGE_SIZE,
 329                  * but we are limited to mapping PAGE_SIZE at a time.
 330                  */
 331                 off = offset + sg->offset;
 332                 sg_bytes = min(sg_bytes, (size_t)
 333                                (PAGE_SIZE - (off & ~PAGE_MASK)));
 334                 page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT),
 335                                         KM_SOFTIRQ0);
 336                 if (!page_addr)
 337                         break;          /* XXX panic? */
 338
 339                 if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 340                         crc = crc32(crc, buf, sg_bytes);
 341                 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf,
 342                        sg_bytes);
 343
 344                 kunmap_atomic(page_addr, KM_SOFTIRQ0);
 345                 buf += sg_bytes;
 346                 offset += sg_bytes;
 347                 remaining -= sg_bytes;
 348                 copy_len += sg_bytes;
 349         }
 350
 351         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
 352                 buf = fc_frame_payload_get(fp, 0);
 353                 if (len % 4) {
 354                         crc = crc32(crc, buf + len, 4 - (len % 4));
 355                         len += 4 - (len % 4);
 356                 }
 357
 358                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 359 crc_err:
 360                         stats = lp->dev_stats[smp_processor_id()];
 361                         stats->ErrorFrames++;
 362                         if (stats->InvalidCRCCount++ < 5)
 363                                 FC_DBG("CRC error on data frame\n");
 364                         /*
 365                          * Assume the frame is total garbage.
 366                          * We may have copied it over the good part
 367                          * of the buffer.
 368                          * If so, we need to retry the entire operation.
 369                          * Otherwise, ignore it.
 370                          */
 371                         if (fsp->state & FC_SRB_DISCONTIG)
 372                                 fc_fcp_retry_cmd(fsp);
 373                         return;
 374                 }
 375         }
 376
 377         if (fsp->xfer_contig_end == start_offset)
 378                 fsp->xfer_contig_end += copy_len;
 379         fsp->xfer_len += copy_len;
 380
 381         /*
 382          * In the very rare event that this data arrived after the response
 383          * and completes the transfer, call the completion handler.
 384          */
 385         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 386             fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
 387                 fc_fcp_complete_locked(fsp);
 388 }
 389
 390 /*
 391  * fc_fcp_send_data -  Send SCSI data to target.
 392  * @fsp: ptr to fc_fcp_pkt
 393  * @sp: ptr to this sequence
 394  * @offset: starting offset for this data request
 395  * @seq_blen: the burst length for this data request
 396  *
 397  * Called after receiving a Transfer Ready data descriptor.
 398  * if LLD is capable of seq offload then send down seq_blen
 399  * size of data in single frame, otherwise send multiple FC
 400  * frames of max FC frame payload supported by target port.
 401  *
 402  * Returns : 0 for success.
 403  */
 404 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 405                             size_t offset, size_t seq_blen)
 406 {
 407         struct fc_exch *ep;
 408         struct scsi_cmnd *sc;
 409         struct scatterlist *sg;
 410         struct fc_frame *fp = NULL;
 411         struct fc_lport *lp = fsp->lp;
 412         size_t remaining;
 413         size_t t_blen;
 414         size_t tlen;
 415         size_t sg_bytes;
 416         size_t frame_offset, fh_parm_offset;
 417         int error;
 418         void *data = NULL;
 419         void *page_addr;
 420         int using_sg = lp->sg_supp;
 421         u32 f_ctl;
 422
 423         WARN_ON(seq_blen <= 0);
 424         if (unlikely(offset + seq_blen > fsp->data_len)) {
 425                 /* this should never happen */
 426                 FC_DEBUG_FCP("xfer-ready past end. seq_blen %zx offset %zx\n",
 427                              seq_blen, offset);
 428                 fc_fcp_send_abort(fsp);
 429                 return 0;
 430         } else if (offset != fsp->xfer_len) {
 431                 /* Out of Order Data Request - no problem, but unexpected. */
 432                 FC_DEBUG_FCP("xfer-ready non-contiguous. "
 433                              "seq_blen %zx offset %zx\n", seq_blen, offset);
 434         }
 435
 436         /*
 437          * if LLD is capable of seq_offload then set transport
 438          * burst length (t_blen) to seq_blen, otherwise set t_blen
 439          * to max FC frame payload previously set in fsp->max_payload.
 440          */
 441         t_blen = lp->seq_offload ? seq_blen : fsp->max_payload;
 442         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
 443         if (t_blen > 512)
 444                 t_blen &= ~(512 - 1);   /* round down to block size */
 445         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);   /* won't go below 256 */
 446         sc = fsp->cmd;
 447
 448         remaining = seq_blen;
 449         fh_parm_offset = frame_offset = offset;
 450         tlen = 0;
 451         seq = lp->tt.seq_start_next(seq);
 452         f_ctl = FC_FC_REL_OFF;
 453         WARN_ON(!seq);
 454
 455         /*
 456          * If a get_page()/put_page() will fail, don't use sg lists
 457          * in the fc_frame structure.
 458          *
 459          * The put_page() may be long after the I/O has completed
 460          * in the case of FCoE, since the network driver does it
 461          * via free_skb().  See the test in free_pages_check().
 462          *
 463          * Test this case with 'dd </dev/zero >/dev/st0 bs=64k'.
 464          */
 465         if (using_sg) {
 466                 for (sg = scsi_sglist(sc); sg; sg = sg_next(sg)) {
 467                         if (page_count(sg_page(sg)) == 0 ||
 468                             (sg_page(sg)->flags & (1 << PG_lru |
 469                                                    1 << PG_private |
 470                                                    1 << PG_locked |
 471                                                    1 << PG_active |
 472                                                    1 << PG_slab |
 473                                                    1 << PG_swapcache |
 474                                                    1 << PG_writeback |
 475                                                    1 << PG_reserved |
 476                                                    1 << PG_buddy))) {
 477                                 using_sg = 0;
 478                                 break;
 479                         }
 480                 }
 481         }
 482         sg = scsi_sglist(sc);
 483
 484         while (remaining > 0 && sg) {
 485                 if (offset >= sg->length) {
 486                         offset -= sg->length;
 487                         sg = sg_next(sg);
 488                         continue;
 489                 }
 490                 if (!fp) {
 491                         tlen = min(t_blen, remaining);
 492
 493                         /*
 494                          * TODO.  Temporary workaround.  fc_seq_send() can't
 495                          * handle odd lengths in non-linear skbs.
 496                          * This will be the final fragment only.
 497                          */
 498                         if (tlen % 4)
 499                                 using_sg = 0;
 500                         if (using_sg) {
 501                                 fp = _fc_frame_alloc(lp, 0);
 502                                 if (!fp)
 503                                         return -ENOMEM;
 504                         } else {
 505                                 fp = fc_frame_alloc(lp, tlen);
 506                                 if (!fp)
 507                                         return -ENOMEM;
 508
 509                                 data = (void *)(fr_hdr(fp)) +
 510                                         sizeof(struct fc_frame_header);
 511                         }
 512                         fh_parm_offset = frame_offset;
 513                         fr_max_payload(fp) = fsp->max_payload;
 514                 }
 515                 sg_bytes = min(tlen, sg->length - offset);
 516                 if (using_sg) {
 517                         WARN_ON(skb_shinfo(fp_skb(fp))->nr_frags >
 518                                 FC_FRAME_SG_LEN);
 519                         get_page(sg_page(sg));
 520                         skb_fill_page_desc(fp_skb(fp),
 521                                            skb_shinfo(fp_skb(fp))->nr_frags,
 522                                            sg_page(sg), sg->offset + offset,
 523                                            sg_bytes);
 524                         fp_skb(fp)->data_len += sg_bytes;
 525                         fr_len(fp) += sg_bytes;
 526                         fp_skb(fp)->truesize += PAGE_SIZE;
 527                 } else {
 528                         size_t off = offset + sg->offset;
 529
 530                         /*
 531                          * The scatterlist item may be bigger than PAGE_SIZE,
 532                          * but we must not cross pages inside the kmap.
 533                          */
 534                         sg_bytes = min(sg_bytes, (size_t) (PAGE_SIZE -
 535                                                            (off & ~PAGE_MASK)));
 536                         page_addr = kmap_atomic(sg_page(sg) +
 537                                                 (off >> PAGE_SHIFT),
 538                                                 KM_SOFTIRQ0);
 539                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 540                                sg_bytes);
 541                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
 542                         data += sg_bytes;
 543                 }
 544                 offset += sg_bytes;
 545                 frame_offset += sg_bytes;
 546                 tlen -= sg_bytes;
 547                 remaining -= sg_bytes;
 548
 549                 if (tlen)
 550                         continue;
 551
 552                 /*
 553                  * Send sequence with transfer sequence initiative in case
 554                  * this is last FCP frame of the sequence.
 555                  */
 556                 if (remaining == 0)
 557                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 558
 559                 ep = fc_seq_exch(seq);
 560                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 561                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
 562
 563                 /*
 564                  * send fragment using for a sequence.
 565                  */
 566                 error = lp->tt.seq_send(lp, seq, fp);
 567                 if (error) {
 568                         WARN_ON(1);             /* send error should be rare */
 569                         fc_fcp_retry_cmd(fsp);
 570                         return 0;
 571                 }
 572                 fp = NULL;
 573         }
 574         fsp->xfer_len += seq_blen;      /* premature count? */
 575         return 0;
 576 }
 577
 578 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 579 {
 580         int ba_done = 1;
 581         struct fc_ba_rjt *brp;
 582         struct fc_frame_header *fh;
 583
 584         fh = fc_frame_header_get(fp);
 585         switch (fh->fh_r_ctl) {
 586         case FC_RCTL_BA_ACC:
 587                 break;
 588         case FC_RCTL_BA_RJT:
 589                 brp = fc_frame_payload_get(fp, sizeof(*brp));
 590                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 591                         break;
 592                 /* fall thru */
 593         default:
 594                 /*
 595                  * we will let the command timeout
 596                  * and scsi-ml recover in this case,
 597                  * therefore cleared the ba_done flag.
 598                  */
 599                 ba_done = 0;
 600         }
 601
 602         if (ba_done) {
 603                 fsp->state |= FC_SRB_ABORTED;
 604                 fsp->state &= ~FC_SRB_ABORT_PENDING;
 605
 606                 if (fsp->wait_for_comp)
 607                         complete(&fsp->tm_done);
 608                 else
 609                         fc_fcp_complete_locked(fsp);
 610         }
 611 }
 612
 613 /*
 614  * fc_fcp_reduce_can_queue - drop can_queue
 615  * @lp: lport to drop queueing for
 616  *
 617  * If we are getting memory allocation failures, then we may
 618  * be trying to execute too many commands. We let the running
 619  * commands complete or timeout, then try again with a reduced
 620  * can_queue. Eventually we will hit the point where we run
 621  * on all reserved structs.
 622  */
 623 static void fc_fcp_reduce_can_queue(struct fc_lport *lp)
 624 {
 625         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 626         unsigned long flags;
 627         int can_queue;
 628
 629         spin_lock_irqsave(lp->host->host_lock, flags);
 630         if (si->throttled)
 631                 goto done;
 632         si->throttled = 1;
 633
 634         can_queue = lp->host->can_queue;
 635         can_queue >>= 1;
 636         if (!can_queue)
 637                 can_queue = 1;
 638         lp->host->can_queue = can_queue;
 639         shost_printk(KERN_ERR, lp->host, "Could not allocate frame.\n"
 640                      "Reducing can_queue to %d.\n", can_queue);
 641 done:
 642         spin_unlock_irqrestore(lp->host->host_lock, flags);
 643 }
 644
 645 /*
 646  * exch mgr calls this routine to process scsi
 647  * exchanges.
 648  *
 649  * Return   : None
 650  * Context  : called from Soft IRQ context
 651  *            can not called holding list lock
 652  */
 653 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 654 {
 655         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 656         struct fc_lport *lp;
 657         struct fc_frame_header *fh;
 658         struct fcp_txrdy *dd;
 659         u8 r_ctl;
 660         int rc = 0;
 661
 662         if (IS_ERR(fp))
 663                 goto errout;
 664
 665         fh = fc_frame_header_get(fp);
 666         r_ctl = fh->fh_r_ctl;
 667         lp = fsp->lp;
 668
 669         if (!(lp->state & LPORT_ST_READY))
 670                 goto out;
 671         if (fc_fcp_lock_pkt(fsp))
 672                 goto out;
 673         fsp->last_pkt_time = jiffies;
 674
 675         if (fh->fh_type == FC_TYPE_BLS) {
 676                 fc_fcp_abts_resp(fsp, fp);
 677                 goto unlock;
 678         }
 679
 680         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
 681                 goto unlock;
 682
 683         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 684                 /*
 685                  * received XFER RDY from the target
 686                  * need to send data to the target
 687                  */
 688                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 689                 dd = fc_frame_payload_get(fp, sizeof(*dd));
 690                 WARN_ON(!dd);
 691
 692                 rc = fc_fcp_send_data(fsp, seq,
 693                                       (size_t) ntohl(dd->ft_data_ro),
 694                                       (size_t) ntohl(dd->ft_burst_len));
 695                 if (!rc)
 696                         seq->rec_data = fsp->xfer_len;
 697                 else if (rc == -ENOMEM)
 698                         fsp->state |= FC_SRB_NOMEM;
 699         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 700                 /*
 701                  * received a DATA frame
 702                  * next we will copy the data to the system buffer
 703                  */
 704                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
 705                 fc_fcp_recv_data(fsp, fp);
 706                 seq->rec_data = fsp->xfer_contig_end;
 707         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 708                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 709
 710                 fc_fcp_resp(fsp, fp);
 711         } else {
 712                 FC_DBG("unexpected frame.  r_ctl %x\n", r_ctl);
 713         }
 714 unlock:
 715         fc_fcp_unlock_pkt(fsp);
 716 out:
 717         fc_frame_free(fp);
 718 errout:
 719         if (IS_ERR(fp))
 720                 fc_fcp_error(fsp, fp);
 721         else if (rc == -ENOMEM)
 722                 fc_fcp_reduce_can_queue(lp);
 723 }
 724
 725 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 726 {
 727         struct fc_frame_header *fh;
 728         struct fcp_resp *fc_rp;
 729         struct fcp_resp_ext *rp_ex;
 730         struct fcp_resp_rsp_info *fc_rp_info;
 731         u32 plen;
 732         u32 expected_len;
 733         u32 respl = 0;
 734         u32 snsl = 0;
 735         u8 flags = 0;
 736
 737         plen = fr_len(fp);
 738         fh = (struct fc_frame_header *)fr_hdr(fp);
 739         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 740                 goto len_err;
 741         plen -= sizeof(*fh);
 742         fc_rp = (struct fcp_resp *)(fh + 1);
 743         fsp->cdb_status = fc_rp->fr_status;
 744         flags = fc_rp->fr_flags;
 745         fsp->scsi_comp_flags = flags;
 746         expected_len = fsp->data_len;
 747
 748         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 749                 rp_ex = (void *)(fc_rp + 1);
 750                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 751                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 752                                 goto len_err;
 753                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 754                         if (flags & FCP_RSP_LEN_VAL) {
 755                                 respl = ntohl(rp_ex->fr_rsp_len);
 756                                 if (respl != sizeof(*fc_rp_info))
 757                                         goto len_err;
 758                                 if (fsp->wait_for_comp) {
 759                                         /* Abuse cdb_status for rsp code */
 760                                         fsp->cdb_status = fc_rp_info->rsp_code;
 761                                         complete(&fsp->tm_done);
 762                                         /*
 763                                          * tmfs will not have any scsi cmd so
 764                                          * exit here
 765                                          */
 766                                         return;
 767                                 } else
 768                                         goto err;
 769                         }
 770                         if (flags & FCP_SNS_LEN_VAL) {
 771                                 snsl = ntohl(rp_ex->fr_sns_len);
 772                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
 773                                         snsl = SCSI_SENSE_BUFFERSIZE;
 774                                 memcpy(fsp->cmd->sense_buffer,
 775                                        (char *)fc_rp_info + respl, snsl);
 776                         }
 777                 }
 778                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 779                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 780                                 goto len_err;
 781                         if (flags & FCP_RESID_UNDER) {
 782                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 783                                 /*
 784                                  * The cmnd->underflow is the minimum number of
 785                                  * bytes that must be transfered for this
 786                                  * command.  Provided a sense condition is not
 787                                  * present, make sure the actual amount
 788                                  * transferred is at least the underflow value
 789                                  * or fail.
 790                                  */
 791                                 if (!(flags & FCP_SNS_LEN_VAL) &&
 792                                     (fc_rp->fr_status == 0) &&
 793                                     (scsi_bufflen(fsp->cmd) -
 794                                      fsp->scsi_resid) < fsp->cmd->underflow)
 795                                         goto err;
 796                                 expected_len -= fsp->scsi_resid;
 797                         } else {
 798                                 fsp->status_code = FC_ERROR;
 799                         }
 800                 }
 801         }
 802         fsp->state |= FC_SRB_RCV_STATUS;
 803
 804         /*
 805          * Check for missing or extra data frames.
 806          */
 807         if (unlikely(fsp->xfer_len != expected_len)) {
 808                 if (fsp->xfer_len < expected_len) {
 809                         /*
 810                          * Some data may be queued locally,
 811                          * Wait a at least one jiffy to see if it is delivered.
 812                          * If this expires without data, we may do SRR.
 813                          */
 814                         fc_fcp_timer_set(fsp, 2);
 815                         return;
 816                 }
 817                 fsp->status_code = FC_DATA_OVRRUN;
 818                 FC_DBG("tgt %6x xfer len %zx greater than expected len %x. "
 819                        "data len %x\n",
 820                        fsp->rport->port_id,
 821                        fsp->xfer_len, expected_len, fsp->data_len);
 822         }
 823         fc_fcp_complete_locked(fsp);
 824         return;
 825
 826 len_err:
 827         FC_DBG("short FCP response. flags 0x%x len %u respl %u snsl %u\n",
 828                flags, fr_len(fp), respl, snsl);
 829 err:
 830         fsp->status_code = FC_ERROR;
 831         fc_fcp_complete_locked(fsp);
 832 }
 833
 834 /**
 835  * fc_fcp_complete_locked - complete processing of a fcp packet
 836  * @fsp:        fcp packet
 837  *
 838  * This function may sleep if a timer is pending. The packet lock must be
 839  * held, and the host lock must not be held.
 840  */
 841 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 842 {
 843         struct fc_lport *lp = fsp->lp;
 844         struct fc_seq *seq;
 845         struct fc_exch *ep;
 846         u32 f_ctl;
 847
 848         if (fsp->state & FC_SRB_ABORT_PENDING)
 849                 return;
 850
 851         if (fsp->state & FC_SRB_ABORTED) {
 852                 if (!fsp->status_code)
 853                         fsp->status_code = FC_CMD_ABORTED;
 854         } else {
 855                 /*
 856                  * Test for transport underrun, independent of response
 857                  * underrun status.
 858                  */
 859                 if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
 860                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
 861                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
 862                         fsp->status_code = FC_DATA_UNDRUN;
 863                         fsp->io_status = SUGGEST_RETRY << 24;
 864                 }
 865         }
 866
 867         seq = fsp->seq_ptr;
 868         if (seq) {
 869                 fsp->seq_ptr = NULL;
 870                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
 871                         struct fc_frame *conf_frame;
 872                         struct fc_seq *csp;
 873
 874                         csp = lp->tt.seq_start_next(seq);
 875                         conf_frame = fc_frame_alloc(fsp->lp, 0);
 876                         if (conf_frame) {
 877                                 f_ctl = FC_FC_SEQ_INIT;
 878                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
 879                                 ep = fc_seq_exch(seq);
 880                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
 881                                                ep->did, ep->sid,
 882                                                FC_TYPE_FCP, f_ctl, 0);
 883                                 lp->tt.seq_send(lp, csp, conf_frame);
 884                         }
 885                 }
 886                 lp->tt.exch_done(seq);
 887         }
 888         fc_io_compl(fsp);
 889 }
 890
 891 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
 892 {
 893         struct fc_lport *lp = fsp->lp;
 894
 895         if (fsp->seq_ptr) {
 896                 lp->tt.exch_done(fsp->seq_ptr);
 897                 fsp->seq_ptr = NULL;
 898         }
 899         fsp->status_code = error;
 900 }
 901
 902 /**
 903  * fc_fcp_cleanup_each_cmd - run fn on each active command
 904  * @lp:         logical port
 905  * @id:         target id
 906  * @lun:        lun
 907  * @error:      fsp status code
 908  *
 909  * If lun or id is -1, they are ignored.
 910  */
 911 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lp, unsigned int id,
 912                                     unsigned int lun, int error)
 913 {
 914         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 915         struct fc_fcp_pkt *fsp;
 916         struct scsi_cmnd *sc_cmd;
 917         unsigned long flags;
 918
 919         spin_lock_irqsave(lp->host->host_lock, flags);
 920 restart:
 921         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
 922                 sc_cmd = fsp->cmd;
 923                 if (id != -1 && scmd_id(sc_cmd) != id)
 924                         continue;
 925
 926                 if (lun != -1 && sc_cmd->device->lun != lun)
 927                         continue;
 928
 929                 fc_fcp_pkt_hold(fsp);
 930                 spin_unlock_irqrestore(lp->host->host_lock, flags);
 931
 932                 if (!fc_fcp_lock_pkt(fsp)) {
 933                         fc_fcp_cleanup_cmd(fsp, error);
 934                         fc_io_compl(fsp);
 935                         fc_fcp_unlock_pkt(fsp);
 936                 }
 937
 938                 fc_fcp_pkt_release(fsp);
 939                 spin_lock_irqsave(lp->host->host_lock, flags);
 940                 /*
 941                  * while we dropped the lock multiple pkts could
 942                  * have been released, so we have to start over.
 943                  */
 944                 goto restart;
 945         }
 946         spin_unlock_irqrestore(lp->host->host_lock, flags);
 947 }
 948
 949 static void fc_fcp_abort_io(struct fc_lport *lp)
 950 {
 951         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_HRD_ERROR);
 952 }
 953
 954 /**
 955  * fc_fcp_pkt_send - send a fcp packet to the lower level.
 956  * @lp:         fc lport
 957  * @fsp:        fc packet.
 958  *
 959  * This is called by upper layer protocol.
 960  * Return   : zero for success and -1 for failure
 961  * Context  : called from queuecommand which can be called from process
 962  *            or scsi soft irq.
 963  * Locks    : called with the host lock and irqs disabled.
 964  */
 965 static int fc_fcp_pkt_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
 966 {
 967         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 968         int rc;
 969
 970         fsp->cmd->SCp.ptr = (char *)fsp;
 971         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
 972         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
 973
 974         int_to_scsilun(fsp->cmd->device->lun,
 975                        (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
 976         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
 977         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
 978
 979         spin_unlock_irq(lp->host->host_lock);
 980         rc = lp->tt.fcp_cmd_send(lp, fsp, fc_fcp_recv);
 981         spin_lock_irq(lp->host->host_lock);
 982         if (rc)
 983                 list_del(&fsp->list);
 984
 985         return rc;
 986 }
 987
 988 static int fc_fcp_cmd_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
 989                            void (*resp)(struct fc_seq *,
 990                                         struct fc_frame *fp,
 991                                         void *arg))
 992 {
 993         struct fc_frame *fp;
 994         struct fc_seq *seq;
 995         struct fc_rport *rport;
 996         struct fc_rport_libfc_priv *rp;
 997         const size_t len = sizeof(fsp->cdb_cmd);
 998         int rc = 0;
 999
1000         if (fc_fcp_lock_pkt(fsp))
1001                 return 0;
1002
1003         fp = fc_frame_alloc(lp, sizeof(fsp->cdb_cmd));
1004         if (!fp) {
1005                 rc = -1;
1006                 goto unlock;
1007         }
1008
1009         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1010         fr_cmd(fp) = fsp->cmd;
1011         rport = fsp->rport;
1012         fsp->max_payload = rport->maxframe_size;
1013         rp = rport->dd_data;
1014
1015         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1016                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1017                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1018
1019         seq = lp->tt.exch_seq_send(lp, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1020         if (!seq) {
1021                 fc_frame_free(fp);
1022                 rc = -1;
1023                 goto unlock;
1024         }
1025         fsp->last_pkt_time = jiffies;
1026         fsp->seq_ptr = seq;
1027         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1028
1029         setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1030         fc_fcp_timer_set(fsp,
1031                          (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
1032                          FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
1033 unlock:
1034         fc_fcp_unlock_pkt(fsp);
1035         return rc;
1036 }
1037
1038 /*
1039  * transport error handler
1040  */
1041 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1042 {
1043         int error = PTR_ERR(fp);
1044
1045         if (fc_fcp_lock_pkt(fsp))
1046                 return;
1047
1048         switch (error) {
1049         case -FC_EX_CLOSED:
1050                 fc_fcp_retry_cmd(fsp);
1051                 goto unlock;
1052         default:
1053                 FC_DBG("unknown error %ld\n", PTR_ERR(fp));
1054         }
1055         /*
1056          * clear abort pending, because the lower layer
1057          * decided to force completion.
1058          */
1059         fsp->state &= ~FC_SRB_ABORT_PENDING;
1060         fsp->status_code = FC_CMD_PLOGO;
1061         fc_fcp_complete_locked(fsp);
1062 unlock:
1063         fc_fcp_unlock_pkt(fsp);
1064 }
1065
1066 /*
1067  * Scsi abort handler- calls to send an abort
1068  * and then wait for abort completion
1069  */
1070 static int fc_fcp_pkt_abort(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1071 {
1072         int rc = FAILED;
1073
1074         if (fc_fcp_send_abort(fsp))
1075                 return FAILED;
1076
1077         init_completion(&fsp->tm_done);
1078         fsp->wait_for_comp = 1;
1079
1080         spin_unlock_bh(&fsp->scsi_pkt_lock);
1081         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1082         spin_lock_bh(&fsp->scsi_pkt_lock);
1083         fsp->wait_for_comp = 0;
1084
1085         if (!rc) {
1086                 FC_DBG("target abort cmd  failed\n");
1087                 rc = FAILED;
1088         } else if (fsp->state & FC_SRB_ABORTED) {
1089                 FC_DBG("target abort cmd  passed\n");
1090                 rc = SUCCESS;
1091                 fc_fcp_complete_locked(fsp);
1092         }
1093
1094         return rc;
1095 }
1096
1097 /*
1098  * Retry LUN reset after resource allocation failed.
1099  */
1100 static void fc_lun_reset_send(unsigned long data)
1101 {
1102         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1103         struct fc_lport *lp = fsp->lp;
1104         if (lp->tt.fcp_cmd_send(lp, fsp, fc_tm_done)) {
1105                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1106                         return;
1107                 if (fc_fcp_lock_pkt(fsp))
1108                         return;
1109                 setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1110                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1111                 fc_fcp_unlock_pkt(fsp);
1112         }
1113 }
1114
1115 /*
1116  * Scsi device reset handler- send a LUN RESET to the device
1117  * and wait for reset reply
1118  */
1119 static int fc_lun_reset(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1120                         unsigned int id, unsigned int lun)
1121 {
1122         int rc;
1123
1124         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1125         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1126         int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1127
1128         fsp->wait_for_comp = 1;
1129         init_completion(&fsp->tm_done);
1130
1131         fc_lun_reset_send((unsigned long)fsp);
1132
1133         /*
1134          * wait for completion of reset
1135          * after that make sure all commands are terminated
1136          */
1137         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1138
1139         spin_lock_bh(&fsp->scsi_pkt_lock);
1140         fsp->state |= FC_SRB_COMPL;
1141         spin_unlock_bh(&fsp->scsi_pkt_lock);
1142
1143         del_timer_sync(&fsp->timer);
1144
1145         spin_lock_bh(&fsp->scsi_pkt_lock);
1146         if (fsp->seq_ptr) {
1147                 lp->tt.exch_done(fsp->seq_ptr);
1148                 fsp->seq_ptr = NULL;
1149         }
1150         fsp->wait_for_comp = 0;
1151         spin_unlock_bh(&fsp->scsi_pkt_lock);
1152
1153         if (!rc) {
1154                 FC_DBG("lun reset failed\n");
1155                 return FAILED;
1156         }
1157
1158         /* cdb_status holds the tmf's rsp code */
1159         if (fsp->cdb_status != FCP_TMF_CMPL)
1160                 return FAILED;
1161
1162         FC_DBG("lun reset to lun %u completed\n", lun);
1163         fc_fcp_cleanup_each_cmd(lp, id, lun, FC_CMD_ABORTED);
1164         return SUCCESS;
1165 }
1166
1167 /*
1168  * Task Managment response handler
1169  */
1170 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1171 {
1172         struct fc_fcp_pkt *fsp = arg;
1173         struct fc_frame_header *fh;
1174
1175         if (IS_ERR(fp)) {
1176                 /*
1177                  * If there is an error just let it timeout or wait
1178                  * for TMF to be aborted if it timedout.
1179                  *
1180                  * scsi-eh will escalate for when either happens.
1181                  */
1182                 return;
1183         }
1184
1185         if (fc_fcp_lock_pkt(fsp))
1186                 return;
1187
1188         /*
1189          * raced with eh timeout handler.
1190          */
1191         if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1192                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1193                 return;
1194         }
1195
1196         fh = fc_frame_header_get(fp);
1197         if (fh->fh_type != FC_TYPE_BLS)
1198                 fc_fcp_resp(fsp, fp);
1199         fsp->seq_ptr = NULL;
1200         fsp->lp->tt.exch_done(seq);
1201         fc_frame_free(fp);
1202         fc_fcp_unlock_pkt(fsp);
1203 }
1204
1205 static void fc_fcp_cleanup(struct fc_lport *lp)
1206 {
1207         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_ERROR);
1208 }
1209
1210 /*
1211  * fc_fcp_timeout: called by OS timer function.
1212  *
1213  * The timer has been inactivated and must be reactivated if desired
1214  * using fc_fcp_timer_set().
1215  *
1216  * Algorithm:
1217  *
1218  * If REC is supported, just issue it, and return.  The REC exchange will
1219  * complete or time out, and recovery can continue at that point.
1220  *
1221  * Otherwise, if the response has been received without all the data,
1222  * it has been ER_TIMEOUT since the response was received.
1223  *
1224  * If the response has not been received,
1225  * we see if data was received recently.  If it has been, we continue waiting,
1226  * otherwise, we abort the command.
1227  */
1228 static void fc_fcp_timeout(unsigned long data)
1229 {
1230         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1231         struct fc_rport *rport = fsp->rport;
1232         struct fc_rport_libfc_priv *rp = rport->dd_data;
1233
1234         if (fc_fcp_lock_pkt(fsp))
1235                 return;
1236
1237         if (fsp->cdb_cmd.fc_tm_flags)
1238                 goto unlock;
1239
1240         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1241
1242         if (rp->flags & FC_RP_FLAGS_REC_SUPPORTED)
1243                 fc_fcp_rec(fsp);
1244         else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
1245                                jiffies))
1246                 fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1247         else if (fsp->state & FC_SRB_RCV_STATUS)
1248                 fc_fcp_complete_locked(fsp);
1249         else
1250                 fc_timeout_error(fsp);
1251         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1252 unlock:
1253         fc_fcp_unlock_pkt(fsp);
1254 }
1255
1256 /*
1257  * Send a REC ELS request
1258  */
1259 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1260 {
1261         struct fc_lport *lp;
1262         struct fc_frame *fp;
1263         struct fc_rport *rport;
1264         struct fc_rport_libfc_priv *rp;
1265
1266         lp = fsp->lp;
1267         rport = fsp->rport;
1268         rp = rport->dd_data;
1269         if (!fsp->seq_ptr || rp->rp_state != RPORT_ST_READY) {
1270                 fsp->status_code = FC_HRD_ERROR;
1271                 fsp->io_status = SUGGEST_RETRY << 24;
1272                 fc_fcp_complete_locked(fsp);
1273                 return;
1274         }
1275         fp = fc_frame_alloc(lp, sizeof(struct fc_els_rec));
1276         if (!fp)
1277                 goto retry;
1278
1279         fr_seq(fp) = fsp->seq_ptr;
1280         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1281                        fc_host_port_id(rp->local_port->host), FC_TYPE_ELS,
1282                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1283         if (lp->tt.elsct_send(lp, rport, fp, ELS_REC, fc_fcp_rec_resp,
1284                               fsp, jiffies_to_msecs(FC_SCSI_REC_TOV))) {
1285                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1286                 return;
1287         }
1288         fc_frame_free(fp);
1289 retry:
1290         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1291                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1292         else
1293                 fc_timeout_error(fsp);
1294 }
1295
1296 /*
1297  * Receive handler for REC ELS frame
1298  * if it is a reject then let the scsi layer to handle
1299  * the timeout. if it is a LS_ACC then if the io was not completed
1300  * then set the timeout and return otherwise complete the exchange
1301  * and tell the scsi layer to restart the I/O.
1302  */
1303 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1304 {
1305         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1306         struct fc_els_rec_acc *recp;
1307         struct fc_els_ls_rjt *rjt;
1308         u32 e_stat;
1309         u8 opcode;
1310         u32 offset;
1311         enum dma_data_direction data_dir;
1312         enum fc_rctl r_ctl;
1313         struct fc_rport_libfc_priv *rp;
1314
1315         if (IS_ERR(fp)) {
1316                 fc_fcp_rec_error(fsp, fp);
1317                 return;
1318         }
1319
1320         if (fc_fcp_lock_pkt(fsp))
1321                 goto out;
1322
1323         fsp->recov_retry = 0;
1324         opcode = fc_frame_payload_op(fp);
1325         if (opcode == ELS_LS_RJT) {
1326                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1327                 switch (rjt->er_reason) {
1328                 default:
1329                         FC_DEBUG_FCP("device %x unexpected REC reject "
1330                                      "reason %d expl %d\n",
1331                                      fsp->rport->port_id, rjt->er_reason,
1332                                      rjt->er_explan);
1333                         /* fall through */
1334                 case ELS_RJT_UNSUP:
1335                         FC_DEBUG_FCP("device does not support REC\n");
1336                         rp = fsp->rport->dd_data;
1337                         /*
1338                          * if we do not spport RECs or got some bogus
1339                          * reason then resetup timer so we check for
1340                          * making progress.
1341                          */
1342                         rp->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1343                         fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1344                         break;
1345                 case ELS_RJT_LOGIC:
1346                 case ELS_RJT_UNAB:
1347                         /*
1348                          * If no data transfer, the command frame got dropped
1349                          * so we just retry.  If data was transferred, we
1350                          * lost the response but the target has no record,
1351                          * so we abort and retry.
1352                          */
1353                         if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1354                             fsp->xfer_len == 0) {
1355                                 fc_fcp_retry_cmd(fsp);
1356                                 break;
1357                         }
1358                         fc_timeout_error(fsp);
1359                         break;
1360                 }
1361         } else if (opcode == ELS_LS_ACC) {
1362                 if (fsp->state & FC_SRB_ABORTED)
1363                         goto unlock_out;
1364
1365                 data_dir = fsp->cmd->sc_data_direction;
1366                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1367                 offset = ntohl(recp->reca_fc4value);
1368                 e_stat = ntohl(recp->reca_e_stat);
1369
1370                 if (e_stat & ESB_ST_COMPLETE) {
1371
1372                         /*
1373                          * The exchange is complete.
1374                          *
1375                          * For output, we must've lost the response.
1376                          * For input, all data must've been sent.
1377                          * We lost may have lost the response
1378                          * (and a confirmation was requested) and maybe
1379                          * some data.
1380                          *
1381                          * If all data received, send SRR
1382                          * asking for response.  If partial data received,
1383                          * or gaps, SRR requests data at start of gap.
1384                          * Recovery via SRR relies on in-order-delivery.
1385                          */
1386                         if (data_dir == DMA_TO_DEVICE) {
1387                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1388                         } else if (fsp->xfer_contig_end == offset) {
1389                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1390                         } else {
1391                                 offset = fsp->xfer_contig_end;
1392                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1393                         }
1394                         fc_fcp_srr(fsp, r_ctl, offset);
1395                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1396
1397                         /*
1398                          * The remote port has the initiative, so just
1399                          * keep waiting for it to complete.
1400                          */
1401                         fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1402                 } else {
1403
1404                         /*
1405                          * The exchange is incomplete, we have seq. initiative.
1406                          * Lost response with requested confirmation,
1407                          * lost confirmation, lost transfer ready or
1408                          * lost write data.
1409                          *
1410                          * For output, if not all data was received, ask
1411                          * for transfer ready to be repeated.
1412                          *
1413                          * If we received or sent all the data, send SRR to
1414                          * request response.
1415                          *
1416                          * If we lost a response, we may have lost some read
1417                          * data as well.
1418                          */
1419                         r_ctl = FC_RCTL_DD_SOL_DATA;
1420                         if (data_dir == DMA_TO_DEVICE) {
1421                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1422                                 if (offset < fsp->data_len)
1423                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1424                         } else if (offset == fsp->xfer_contig_end) {
1425                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1426                         } else if (fsp->xfer_contig_end < offset) {
1427                                 offset = fsp->xfer_contig_end;
1428                         }
1429                         fc_fcp_srr(fsp, r_ctl, offset);
1430                 }
1431         }
1432 unlock_out:
1433         fc_fcp_unlock_pkt(fsp);
1434 out:
1435         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1436         fc_frame_free(fp);
1437 }
1438
1439 /*
1440  * Handle error response or timeout for REC exchange.
1441  */
1442 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1443 {
1444         int error = PTR_ERR(fp);
1445
1446         if (fc_fcp_lock_pkt(fsp))
1447                 goto out;
1448
1449         switch (error) {
1450         case -FC_EX_CLOSED:
1451                 fc_fcp_retry_cmd(fsp);
1452                 break;
1453
1454         default:
1455                 FC_DBG("REC %p fid %x error unexpected error %d\n",
1456                        fsp, fsp->rport->port_id, error);
1457                 fsp->status_code = FC_CMD_PLOGO;
1458                 /* fall through */
1459
1460         case -FC_EX_TIMEOUT:
1461                 /*
1462                  * Assume REC or LS_ACC was lost.
1463                  * The exchange manager will have aborted REC, so retry.
1464                  */
1465                 FC_DBG("REC fid %x error error %d retry %d/%d\n",
1466                        fsp->rport->port_id, error, fsp->recov_retry,
1467                        FC_MAX_RECOV_RETRY);
1468                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1469                         fc_fcp_rec(fsp);
1470                 else
1471                         fc_timeout_error(fsp);
1472                 break;
1473         }
1474         fc_fcp_unlock_pkt(fsp);
1475 out:
1476         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1477 }
1478
1479 /*
1480  * Time out error routine:
1481  * abort's the I/O close the exchange and
1482  * send completion notification to scsi layer
1483  */
1484 static void fc_timeout_error(struct fc_fcp_pkt *fsp)
1485 {
1486         fsp->status_code = FC_CMD_TIME_OUT;
1487         fsp->cdb_status = 0;
1488         fsp->io_status = 0;
1489         /*
1490          * if this fails then we let the scsi command timer fire and
1491          * scsi-ml escalate.
1492          */
1493         fc_fcp_send_abort(fsp);
1494 }
1495
1496 /*
1497  * Sequence retransmission request.
1498  * This is called after receiving status but insufficient data, or
1499  * when expecting status but the request has timed out.
1500  */
1501 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1502 {
1503         struct fc_lport *lp = fsp->lp;
1504         struct fc_rport *rport;
1505         struct fc_rport_libfc_priv *rp;
1506         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1507         struct fc_seq *seq;
1508         struct fcp_srr *srr;
1509         struct fc_frame *fp;
1510         u8 cdb_op;
1511
1512         rport = fsp->rport;
1513         rp = rport->dd_data;
1514         cdb_op = fsp->cdb_cmd.fc_cdb[0];
1515
1516         if (!(rp->flags & FC_RP_FLAGS_RETRY) || rp->rp_state != RPORT_ST_READY)
1517                 goto retry;                     /* shouldn't happen */
1518         fp = fc_frame_alloc(lp, sizeof(*srr));
1519         if (!fp)
1520                 goto retry;
1521
1522         srr = fc_frame_payload_get(fp, sizeof(*srr));
1523         memset(srr, 0, sizeof(*srr));
1524         srr->srr_op = ELS_SRR;
1525         srr->srr_ox_id = htons(ep->oxid);
1526         srr->srr_rx_id = htons(ep->rxid);
1527         srr->srr_r_ctl = r_ctl;
1528         srr->srr_rel_off = htonl(offset);
1529
1530         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1531                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1532                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1533
1534         seq = lp->tt.exch_seq_send(lp, fp, fc_fcp_srr_resp, NULL,
1535                                    fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
1536         if (!seq) {
1537                 fc_frame_free(fp);
1538                 goto retry;
1539         }
1540         fsp->recov_seq = seq;
1541         fsp->xfer_len = offset;
1542         fsp->xfer_contig_end = offset;
1543         fsp->state &= ~FC_SRB_RCV_STATUS;
1544         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1545         return;
1546 retry:
1547         fc_fcp_retry_cmd(fsp);
1548 }
1549
1550 /*
1551  * Handle response from SRR.
1552  */
1553 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1554 {
1555         struct fc_fcp_pkt *fsp = arg;
1556         struct fc_frame_header *fh;
1557
1558         if (IS_ERR(fp)) {
1559                 fc_fcp_srr_error(fsp, fp);
1560                 return;
1561         }
1562
1563         if (fc_fcp_lock_pkt(fsp))
1564                 goto out;
1565
1566         fh = fc_frame_header_get(fp);
1567         /*
1568          * BUG? fc_fcp_srr_error calls exch_done which would release
1569          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1570          * then fc_exch_timeout would be sending an abort. The exch_done
1571          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1572          * an abort response though.
1573          */
1574         if (fh->fh_type == FC_TYPE_BLS) {
1575                 fc_fcp_unlock_pkt(fsp);
1576                 return;
1577         }
1578
1579         fsp->recov_seq = NULL;
1580         switch (fc_frame_payload_op(fp)) {
1581         case ELS_LS_ACC:
1582                 fsp->recov_retry = 0;
1583                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1584                 break;
1585         case ELS_LS_RJT:
1586         default:
1587                 fc_timeout_error(fsp);
1588                 break;
1589         }
1590         fc_fcp_unlock_pkt(fsp);
1591         fsp->lp->tt.exch_done(seq);
1592 out:
1593         fc_frame_free(fp);
1594         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1595 }
1596
1597 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1598 {
1599         if (fc_fcp_lock_pkt(fsp))
1600                 goto out;
1601         fsp->lp->tt.exch_done(fsp->recov_seq);
1602         fsp->recov_seq = NULL;
1603         switch (PTR_ERR(fp)) {
1604         case -FC_EX_TIMEOUT:
1605                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1606                         fc_fcp_rec(fsp);
1607                 else
1608                         fc_timeout_error(fsp);
1609                 break;
1610         case -FC_EX_CLOSED:                     /* e.g., link failure */
1611                 /* fall through */
1612         default:
1613                 fc_fcp_retry_cmd(fsp);
1614                 break;
1615         }
1616         fc_fcp_unlock_pkt(fsp);
1617 out:
1618         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1619 }
1620
1621 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp)
1622 {
1623         /* lock ? */
1624         return (lp->state == LPORT_ST_READY) && (lp->link_status & FC_LINK_UP);
1625 }
1626
1627 /**
1628  * fc_queuecommand - The queuecommand function of the scsi template
1629  * @cmd:        struct scsi_cmnd to be executed
1630  * @done:       Callback function to be called when cmd is completed
1631  *
1632  * this is the i/o strategy routine, called by the scsi layer
1633  * this routine is called with holding the host_lock.
1634  */
1635 int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1636 {
1637         struct fc_lport *lp;
1638         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1639         struct fc_fcp_pkt *fsp;
1640         struct fc_rport_libfc_priv *rp;
1641         int rval;
1642         int rc = 0;
1643         struct fcoe_dev_stats *stats;
1644
1645         lp = shost_priv(sc_cmd->device->host);
1646
1647         rval = fc_remote_port_chkready(rport);
1648         if (rval) {
1649                 sc_cmd->result = rval;
1650                 done(sc_cmd);
1651                 goto out;
1652         }
1653
1654         if (!*(struct fc_remote_port **)rport->dd_data) {
1655                 /*
1656                  * rport is transitioning from blocked/deleted to
1657                  * online
1658                  */
1659                 sc_cmd->result = DID_IMM_RETRY << 16;
1660                 done(sc_cmd);
1661                 goto out;
1662         }
1663
1664         rp = rport->dd_data;
1665
1666         if (!fc_fcp_lport_queue_ready(lp)) {
1667                 rc = SCSI_MLQUEUE_HOST_BUSY;
1668                 goto out;
1669         }
1670
1671         fsp = fc_fcp_pkt_alloc(lp, GFP_ATOMIC);
1672         if (fsp == NULL) {
1673                 rc = SCSI_MLQUEUE_HOST_BUSY;
1674                 goto out;
1675         }
1676
1677         /*
1678          * build the libfc request pkt
1679          */
1680         fsp->cmd = sc_cmd;      /* save the cmd */
1681         fsp->lp = lp;           /* save the softc ptr */
1682         fsp->rport = rport;     /* set the remote port ptr */
1683         sc_cmd->scsi_done = done;
1684
1685         /*
1686          * set up the transfer length
1687          */
1688         fsp->data_len = scsi_bufflen(sc_cmd);
1689         fsp->xfer_len = 0;
1690
1691         /*
1692          * setup the data direction
1693          */
1694         stats = lp->dev_stats[smp_processor_id()];
1695         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1696                 fsp->req_flags = FC_SRB_READ;
1697                 stats->InputRequests++;
1698                 stats->InputMegabytes = fsp->data_len;
1699         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1700                 fsp->req_flags = FC_SRB_WRITE;
1701                 stats->OutputRequests++;
1702                 stats->OutputMegabytes = fsp->data_len;
1703         } else {
1704                 fsp->req_flags = 0;
1705                 stats->ControlRequests++;
1706         }
1707
1708         fsp->tgt_flags = rp->flags;
1709
1710         init_timer(&fsp->timer);
1711         fsp->timer.data = (unsigned long)fsp;
1712
1713         /*
1714          * send it to the lower layer
1715          * if we get -1 return then put the request in the pending
1716          * queue.
1717          */
1718         rval = fc_fcp_pkt_send(lp, fsp);
1719         if (rval != 0) {
1720                 fsp->state = FC_SRB_FREE;
1721                 fc_fcp_pkt_release(fsp);
1722                 rc = SCSI_MLQUEUE_HOST_BUSY;
1723         }
1724 out:
1725         return rc;
1726 }
1727 EXPORT_SYMBOL(fc_queuecommand);
1728
1729 /**
1730  * fc_io_compl -  Handle responses for completed commands
1731  * @fsp:        scsi packet
1732  *
1733  * Translates a error to a Linux SCSI error.
1734  *
1735  * The fcp packet lock must be held when calling.
1736  */
1737 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1738 {
1739         struct fc_fcp_internal *si;
1740         struct scsi_cmnd *sc_cmd;
1741         struct fc_lport *lp;
1742         unsigned long flags;
1743
1744         fsp->state |= FC_SRB_COMPL;
1745         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1746                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1747                 del_timer_sync(&fsp->timer);
1748                 spin_lock_bh(&fsp->scsi_pkt_lock);
1749         }
1750
1751         lp = fsp->lp;
1752         si = fc_get_scsi_internal(lp);
1753         spin_lock_irqsave(lp->host->host_lock, flags);
1754         if (!fsp->cmd) {
1755                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1756                 return;
1757         }
1758
1759         /*
1760          * if a command timed out while we had to try and throttle IO
1761          * and it is now getting cleaned up, then we are about to
1762          * try again so clear the throttled flag incase we get more
1763          * time outs.
1764          */
1765         if (si->throttled && fsp->state & FC_SRB_NOMEM)
1766                 si->throttled = 0;
1767
1768         sc_cmd = fsp->cmd;
1769         fsp->cmd = NULL;
1770
1771         if (!sc_cmd->SCp.ptr) {
1772                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1773                 return;
1774         }
1775
1776         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1777         switch (fsp->status_code) {
1778         case FC_COMPLETE:
1779                 if (fsp->cdb_status == 0) {
1780                         /*
1781                          * good I/O status
1782                          */
1783                         sc_cmd->result = DID_OK << 16;
1784                         if (fsp->scsi_resid)
1785                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1786                 } else if (fsp->cdb_status == QUEUE_FULL) {
1787                         struct scsi_device *tmp_sdev;
1788                         struct scsi_device *sdev = sc_cmd->device;
1789
1790                         shost_for_each_device(tmp_sdev, sdev->host) {
1791                                 if (tmp_sdev->id != sdev->id)
1792                                         continue;
1793
1794                                 if (tmp_sdev->queue_depth > 1) {
1795                                         scsi_track_queue_full(tmp_sdev,
1796                                                               tmp_sdev->
1797                                                               queue_depth - 1);
1798                                 }
1799                         }
1800                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1801                 } else {
1802                         /*
1803                          * transport level I/O was ok but scsi
1804                          * has non zero status
1805                          */
1806                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1807                 }
1808                 break;
1809         case FC_ERROR:
1810                 sc_cmd->result = DID_ERROR << 16;
1811                 break;
1812         case FC_DATA_UNDRUN:
1813                 if (fsp->cdb_status == 0) {
1814                         /*
1815                          * scsi status is good but transport level
1816                          * underrun. for read it should be an error??
1817                          */
1818                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1819                 } else {
1820                         /*
1821                          * scsi got underrun, this is an error
1822                          */
1823                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1824                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1825                 }
1826                 break;
1827         case FC_DATA_OVRRUN:
1828                 /*
1829                  * overrun is an error
1830                  */
1831                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1832                 break;
1833         case FC_CMD_ABORTED:
1834                 sc_cmd->result = (DID_ABORT << 16) | fsp->io_status;
1835                 break;
1836         case FC_CMD_TIME_OUT:
1837                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1838                 break;
1839         case FC_CMD_RESET:
1840                 sc_cmd->result = (DID_RESET << 16);
1841                 break;
1842         case FC_HRD_ERROR:
1843                 sc_cmd->result = (DID_NO_CONNECT << 16);
1844                 break;
1845         default:
1846                 sc_cmd->result = (DID_ERROR << 16);
1847                 break;
1848         }
1849
1850         list_del(&fsp->list);
1851         sc_cmd->SCp.ptr = NULL;
1852         sc_cmd->scsi_done(sc_cmd);
1853         spin_unlock_irqrestore(lp->host->host_lock, flags);
1854
1855         /* release ref from initial allocation in queue command */
1856         fc_fcp_pkt_release(fsp);
1857 }
1858
1859 /**
1860  * fc_fcp_complete - complete processing of a fcp packet
1861  * @fsp:        fcp packet
1862  *
1863  * This function may sleep if a fsp timer is pending.
1864  * The host lock must not be held by caller.
1865  */
1866 void fc_fcp_complete(struct fc_fcp_pkt *fsp)
1867 {
1868         if (fc_fcp_lock_pkt(fsp))
1869                 return;
1870
1871         fc_fcp_complete_locked(fsp);
1872         fc_fcp_unlock_pkt(fsp);
1873 }
1874 EXPORT_SYMBOL(fc_fcp_complete);
1875
1876 /**
1877  * fc_eh_abort - Abort a command...from scsi host template
1878  * @sc_cmd:     scsi command to abort
1879  *
1880  * send ABTS to the target device  and wait for the response
1881  * sc_cmd is the pointer to the command to be aborted.
1882  */
1883 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
1884 {
1885         struct fc_fcp_pkt *fsp;
1886         struct fc_lport *lp;
1887         int rc = FAILED;
1888         unsigned long flags;
1889
1890         lp = shost_priv(sc_cmd->device->host);
1891         if (lp->state != LPORT_ST_READY)
1892                 return rc;
1893         else if (!(lp->link_status & FC_LINK_UP))
1894                 return rc;
1895
1896         spin_lock_irqsave(lp->host->host_lock, flags);
1897         fsp = CMD_SP(sc_cmd);
1898         if (!fsp) {
1899                 /* command completed while scsi eh was setting up */
1900                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1901                 return SUCCESS;
1902         }
1903         /* grab a ref so the fsp and sc_cmd cannot be relased from under us */
1904         fc_fcp_pkt_hold(fsp);
1905         spin_unlock_irqrestore(lp->host->host_lock, flags);
1906
1907         if (fc_fcp_lock_pkt(fsp)) {
1908                 /* completed while we were waiting for timer to be deleted */
1909                 rc = SUCCESS;
1910                 goto release_pkt;
1911         }
1912
1913         rc = fc_fcp_pkt_abort(lp, fsp);
1914         fc_fcp_unlock_pkt(fsp);
1915
1916 release_pkt:
1917         fc_fcp_pkt_release(fsp);
1918         return rc;
1919 }
1920 EXPORT_SYMBOL(fc_eh_abort);
1921
1922 /**
1923  * fc_eh_device_reset: Reset a single LUN
1924  * @sc_cmd:     scsi command
1925  *
1926  * Set from scsi host template to send tm cmd to the target and wait for the
1927  * response.
1928  */
1929 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
1930 {
1931         struct fc_lport *lp;
1932         struct fc_fcp_pkt *fsp;
1933         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1934         int rc = FAILED;
1935         struct fc_rport_libfc_priv *rp;
1936         int rval;
1937
1938         rval = fc_remote_port_chkready(rport);
1939         if (rval)
1940                 goto out;
1941
1942         rp = rport->dd_data;
1943         lp = shost_priv(sc_cmd->device->host);
1944
1945         if (lp->state != LPORT_ST_READY)
1946                 return rc;
1947
1948         fsp = fc_fcp_pkt_alloc(lp, GFP_NOIO);
1949         if (fsp == NULL) {
1950                 FC_DBG("could not allocate scsi_pkt\n");
1951                 sc_cmd->result = DID_NO_CONNECT << 16;
1952                 goto out;
1953         }
1954
1955         /*
1956          * Build the libfc request pkt. Do not set the scsi cmnd, because
1957          * the sc passed in is not setup for execution like when sent
1958          * through the queuecommand callout.
1959          */
1960         fsp->lp = lp;           /* save the softc ptr */
1961         fsp->rport = rport;     /* set the remote port ptr */
1962
1963         /*
1964          * flush outstanding commands
1965          */
1966         rc = fc_lun_reset(lp, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
1967         fsp->state = FC_SRB_FREE;
1968         fc_fcp_pkt_release(fsp);
1969
1970 out:
1971         return rc;
1972 }
1973 EXPORT_SYMBOL(fc_eh_device_reset);
1974
1975 /**
1976  * fc_eh_host_reset - The reset function will reset the ports on the host.
1977  * @sc_cmd:     scsi command
1978  */
1979 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
1980 {
1981         struct Scsi_Host *shost = sc_cmd->device->host;
1982         struct fc_lport *lp = shost_priv(shost);
1983         unsigned long wait_tmo;
1984
1985         lp->tt.lport_reset(lp);
1986         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
1987         while (!fc_fcp_lport_queue_ready(lp) && time_before(jiffies, wait_tmo))
1988                 msleep(1000);
1989
1990         if (fc_fcp_lport_queue_ready(lp)) {
1991                 shost_printk(KERN_INFO, shost, "Host reset succeeded.\n");
1992                 return SUCCESS;
1993         } else {
1994                 shost_printk(KERN_INFO, shost, "Host reset failed. "
1995                              "lport not ready.\n");
1996                 return FAILED;
1997         }
1998 }
1999 EXPORT_SYMBOL(fc_eh_host_reset);
2000
2001 /**
2002  * fc_slave_alloc - configure queue depth
2003  * @sdev:       scsi device
2004  *
2005  * Configures queue depth based on host's cmd_per_len. If not set
2006  * then we use the libfc default.
2007  */
2008 int fc_slave_alloc(struct scsi_device *sdev)
2009 {
2010         struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2011         int queue_depth;
2012
2013         if (!rport || fc_remote_port_chkready(rport))
2014                 return -ENXIO;
2015
2016         if (sdev->tagged_supported) {
2017                 if (sdev->host->hostt->cmd_per_lun)
2018                         queue_depth = sdev->host->hostt->cmd_per_lun;
2019                 else
2020                         queue_depth = FC_FCP_DFLT_QUEUE_DEPTH;
2021                 scsi_activate_tcq(sdev, queue_depth);
2022         }
2023         return 0;
2024 }
2025 EXPORT_SYMBOL(fc_slave_alloc);
2026
2027 int fc_change_queue_depth(struct scsi_device *sdev, int qdepth)
2028 {
2029         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2030         return sdev->queue_depth;
2031 }
2032 EXPORT_SYMBOL(fc_change_queue_depth);
2033
2034 int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2035 {
2036         if (sdev->tagged_supported) {
2037                 scsi_set_tag_type(sdev, tag_type);
2038                 if (tag_type)
2039                         scsi_activate_tcq(sdev, sdev->queue_depth);
2040                 else
2041                         scsi_deactivate_tcq(sdev, sdev->queue_depth);
2042         } else
2043                 tag_type = 0;
2044
2045         return tag_type;
2046 }
2047 EXPORT_SYMBOL(fc_change_queue_type);
2048
2049 void fc_fcp_destroy(struct fc_lport *lp)
2050 {
2051         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
2052
2053         if (!list_empty(&si->scsi_pkt_queue))
2054                 printk(KERN_ERR "Leaked scsi packets.\n");
2055
2056         mempool_destroy(si->scsi_pkt_pool);
2057         kfree(si);
2058         lp->scsi_priv = NULL;
2059 }
2060 EXPORT_SYMBOL(fc_fcp_destroy);
2061
2062 int fc_fcp_init(struct fc_lport *lp)
2063 {
2064         int rc;
2065         struct fc_fcp_internal *si;
2066
2067         if (!lp->tt.fcp_cmd_send)
2068                 lp->tt.fcp_cmd_send = fc_fcp_cmd_send;
2069
2070         if (!lp->tt.fcp_cleanup)
2071                 lp->tt.fcp_cleanup = fc_fcp_cleanup;
2072
2073         if (!lp->tt.fcp_abort_io)
2074                 lp->tt.fcp_abort_io = fc_fcp_abort_io;
2075
2076         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2077         if (!si)
2078                 return -ENOMEM;
2079         lp->scsi_priv = si;
2080         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2081
2082         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2083         if (!si->scsi_pkt_pool) {
2084                 rc = -ENOMEM;
2085                 goto free_internal;
2086         }
2087         return 0;
2088
2089 free_internal:
2090         kfree(si);
2091         return rc;
2092 }
2093 EXPORT_SYMBOL(fc_fcp_init);
2094
2095 static int __init libfc_init(void)
2096 {
2097         int rc;
2098
2099         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2100                                             sizeof(struct fc_fcp_pkt),
2101                                             0, SLAB_HWCACHE_ALIGN, NULL);
2102         if (scsi_pkt_cachep == NULL) {
2103                 FC_DBG("Unable to allocate SRB cache...module load failed!");
2104                 return -ENOMEM;
2105         }
2106
2107         rc = fc_setup_exch_mgr();
2108         if (rc)
2109                 goto destroy_pkt_cache;
2110
2111         rc = fc_setup_rport();
2112         if (rc)
2113                 goto destroy_em;
2114
2115         return rc;
2116 destroy_em:
2117         fc_destroy_exch_mgr();
2118 destroy_pkt_cache:
2119         kmem_cache_destroy(scsi_pkt_cachep);
2120         return rc;
2121 }
2122
2123 static void __exit libfc_exit(void)
2124 {
2125         kmem_cache_destroy(scsi_pkt_cachep);
2126         fc_destroy_exch_mgr();
2127         fc_destroy_rport();
2128 }
2129
2130 module_init(libfc_init);
2131 module_exit(libfc_exit);