git.oblomov.eu Git - linux-2.6/blob - 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 v2");
  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  * @seq:                exchange sequence
 188  * @fsp:        fcp packet struct
 189  *
 190  * Release hold on scsi_pkt packet set to keep scsi_pkt
 191  * till EM layer exch resource is not freed.
 192  * Context      : called from from EM layer.
 193  *                no locking required
 194  */
 195 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 196 {
 197         fc_fcp_pkt_release(fsp);
 198 }
 199
 200 /**
 201  * fc_fcp_lock_pkt() - lock a packet and get a ref to it.
 202  * @fsp:        fcp packet
 203  *
 204  * We should only return error if we return a command to scsi-ml before
 205  * getting a response. This can happen in cases where we send a abort, but
 206  * do not wait for the response and the abort and command can be passing
 207  * each other on the wire/network-layer.
 208  *
 209  * Note: this function locks the packet and gets a reference to allow
 210  * callers to call the completion function while the lock is held and
 211  * not have to worry about the packets refcount.
 212  *
 213  * TODO: Maybe we should just have callers grab/release the lock and
 214  * have a function that they call to verify the fsp and grab a ref if
 215  * needed.
 216  */
 217 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 218 {
 219         spin_lock_bh(&fsp->scsi_pkt_lock);
 220         if (fsp->state & FC_SRB_COMPL) {
 221                 spin_unlock_bh(&fsp->scsi_pkt_lock);
 222                 return -EPERM;
 223         }
 224
 225         fc_fcp_pkt_hold(fsp);
 226         return 0;
 227 }
 228
 229 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 230 {
 231         spin_unlock_bh(&fsp->scsi_pkt_lock);
 232         fc_fcp_pkt_release(fsp);
 233 }
 234
 235 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 236 {
 237         if (!(fsp->state & FC_SRB_COMPL))
 238                 mod_timer(&fsp->timer, jiffies + delay);
 239 }
 240
 241 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 242 {
 243         if (!fsp->seq_ptr)
 244                 return -EINVAL;
 245
 246         fsp->state |= FC_SRB_ABORT_PENDING;
 247         return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
 248 }
 249
 250 /*
 251  * Retry command.
 252  * An abort isn't needed.
 253  */
 254 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
 255 {
 256         if (fsp->seq_ptr) {
 257                 fsp->lp->tt.exch_done(fsp->seq_ptr);
 258                 fsp->seq_ptr = NULL;
 259         }
 260
 261         fsp->state &= ~FC_SRB_ABORT_PENDING;
 262         fsp->io_status = 0;
 263         fsp->status_code = FC_ERROR;
 264         fc_fcp_complete_locked(fsp);
 265 }
 266
 267 /*
 268  * fc_fcp_ddp_setup - calls to LLD's ddp_setup to set up DDP
 269  * transfer for a read I/O indicated by the fc_fcp_pkt.
 270  * @fsp: ptr to the fc_fcp_pkt
 271  *
 272  * This is called in exch_seq_send() when we have a newly allocated
 273  * exchange with a valid exchange id to setup ddp.
 274  *
 275  * returns: none
 276  */
 277 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
 278 {
 279         struct fc_lport *lp;
 280
 281         if (!fsp)
 282                 return;
 283
 284         lp = fsp->lp;
 285         if ((fsp->req_flags & FC_SRB_READ) &&
 286             (lp->lro_enabled) && (lp->tt.ddp_setup)) {
 287                 if (lp->tt.ddp_setup(lp, xid, scsi_sglist(fsp->cmd),
 288                                      scsi_sg_count(fsp->cmd)))
 289                         fsp->xfer_ddp = xid;
 290         }
 291 }
 292 EXPORT_SYMBOL(fc_fcp_ddp_setup);
 293
 294 /*
 295  * fc_fcp_ddp_done - calls to LLD's ddp_done to release any
 296  * DDP related resources for this I/O if it is initialized
 297  * as a ddp transfer
 298  * @fsp: ptr to the fc_fcp_pkt
 299  *
 300  * returns: none
 301  */
 302 static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
 303 {
 304         struct fc_lport *lp;
 305
 306         if (!fsp)
 307                 return;
 308
 309         lp = fsp->lp;
 310         if (fsp->xfer_ddp && lp->tt.ddp_done) {
 311                 fsp->xfer_len = lp->tt.ddp_done(lp, fsp->xfer_ddp);
 312                 fsp->xfer_ddp = 0;
 313         }
 314 }
 315
 316
 317 /*
 318  * Receive SCSI data from target.
 319  * Called after receiving solicited data.
 320  */
 321 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 322 {
 323         struct scsi_cmnd *sc = fsp->cmd;
 324         struct fc_lport *lp = fsp->lp;
 325         struct fcoe_dev_stats *stats;
 326         struct fc_frame_header *fh;
 327         size_t start_offset;
 328         size_t offset;
 329         u32 crc;
 330         u32 copy_len = 0;
 331         size_t len;
 332         void *buf;
 333         struct scatterlist *sg;
 334         size_t remaining;
 335
 336         fh = fc_frame_header_get(fp);
 337         offset = ntohl(fh->fh_parm_offset);
 338         start_offset = offset;
 339         len = fr_len(fp) - sizeof(*fh);
 340         buf = fc_frame_payload_get(fp, 0);
 341
 342         /* if this I/O is ddped, update xfer len */
 343         fc_fcp_ddp_done(fsp);
 344
 345         if (offset + len > fsp->data_len) {
 346                 /* this should never happen */
 347                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 348                     fc_frame_crc_check(fp))
 349                         goto crc_err;
 350                 FC_DEBUG_FCP("data received past end. len %zx offset %zx "
 351                              "data_len %x\n", len, offset, fsp->data_len);
 352                 fc_fcp_retry_cmd(fsp);
 353                 return;
 354         }
 355         if (offset != fsp->xfer_len)
 356                 fsp->state |= FC_SRB_DISCONTIG;
 357
 358         crc = 0;
 359         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 360                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 361
 362         sg = scsi_sglist(sc);
 363         remaining = len;
 364
 365         while (remaining > 0 && sg) {
 366                 size_t off;
 367                 void *page_addr;
 368                 size_t sg_bytes;
 369
 370                 if (offset >= sg->length) {
 371                         offset -= sg->length;
 372                         sg = sg_next(sg);
 373                         continue;
 374                 }
 375                 sg_bytes = min(remaining, sg->length - offset);
 376
 377                 /*
 378                  * The scatterlist item may be bigger than PAGE_SIZE,
 379                  * but we are limited to mapping PAGE_SIZE at a time.
 380                  */
 381                 off = offset + sg->offset;
 382                 sg_bytes = min(sg_bytes, (size_t)
 383                                (PAGE_SIZE - (off & ~PAGE_MASK)));
 384                 page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT),
 385                                         KM_SOFTIRQ0);
 386                 if (!page_addr)
 387                         break;          /* XXX panic? */
 388
 389                 if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 390                         crc = crc32(crc, buf, sg_bytes);
 391                 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf,
 392                        sg_bytes);
 393
 394                 kunmap_atomic(page_addr, KM_SOFTIRQ0);
 395                 buf += sg_bytes;
 396                 offset += sg_bytes;
 397                 remaining -= sg_bytes;
 398                 copy_len += sg_bytes;
 399         }
 400
 401         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
 402                 buf = fc_frame_payload_get(fp, 0);
 403                 if (len % 4) {
 404                         crc = crc32(crc, buf + len, 4 - (len % 4));
 405                         len += 4 - (len % 4);
 406                 }
 407
 408                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 409 crc_err:
 410                         stats = fc_lport_get_stats(lp);
 411                         stats->ErrorFrames++;
 412                         /* FIXME - per cpu count, not total count! */
 413                         if (stats->InvalidCRCCount++ < 5)
 414                                 printk(KERN_WARNING "CRC error on data frame for port (%6x)\n",
 415                                        fc_host_port_id(lp->host));
 416                         /*
 417                          * Assume the frame is total garbage.
 418                          * We may have copied it over the good part
 419                          * of the buffer.
 420                          * If so, we need to retry the entire operation.
 421                          * Otherwise, ignore it.
 422                          */
 423                         if (fsp->state & FC_SRB_DISCONTIG)
 424                                 fc_fcp_retry_cmd(fsp);
 425                         return;
 426                 }
 427         }
 428
 429         if (fsp->xfer_contig_end == start_offset)
 430                 fsp->xfer_contig_end += copy_len;
 431         fsp->xfer_len += copy_len;
 432
 433         /*
 434          * In the very rare event that this data arrived after the response
 435          * and completes the transfer, call the completion handler.
 436          */
 437         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 438             fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
 439                 fc_fcp_complete_locked(fsp);
 440 }
 441
 442 /**
 443  * fc_fcp_send_data() -  Send SCSI data to target.
 444  * @fsp: ptr to fc_fcp_pkt
 445  * @sp: ptr to this sequence
 446  * @offset: starting offset for this data request
 447  * @seq_blen: the burst length for this data request
 448  *
 449  * Called after receiving a Transfer Ready data descriptor.
 450  * if LLD is capable of seq offload then send down seq_blen
 451  * size of data in single frame, otherwise send multiple FC
 452  * frames of max FC frame payload supported by target port.
 453  *
 454  * Returns : 0 for success.
 455  */
 456 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 457                             size_t offset, size_t seq_blen)
 458 {
 459         struct fc_exch *ep;
 460         struct scsi_cmnd *sc;
 461         struct scatterlist *sg;
 462         struct fc_frame *fp = NULL;
 463         struct fc_lport *lp = fsp->lp;
 464         size_t remaining;
 465         size_t t_blen;
 466         size_t tlen;
 467         size_t sg_bytes;
 468         size_t frame_offset, fh_parm_offset;
 469         int error;
 470         void *data = NULL;
 471         void *page_addr;
 472         int using_sg = lp->sg_supp;
 473         u32 f_ctl;
 474
 475         WARN_ON(seq_blen <= 0);
 476         if (unlikely(offset + seq_blen > fsp->data_len)) {
 477                 /* this should never happen */
 478                 FC_DEBUG_FCP("xfer-ready past end. seq_blen %zx offset %zx\n",
 479                              seq_blen, offset);
 480                 fc_fcp_send_abort(fsp);
 481                 return 0;
 482         } else if (offset != fsp->xfer_len) {
 483                 /* Out of Order Data Request - no problem, but unexpected. */
 484                 FC_DEBUG_FCP("xfer-ready non-contiguous. "
 485                              "seq_blen %zx offset %zx\n", seq_blen, offset);
 486         }
 487
 488         /*
 489          * if LLD is capable of seq_offload then set transport
 490          * burst length (t_blen) to seq_blen, otherwise set t_blen
 491          * to max FC frame payload previously set in fsp->max_payload.
 492          */
 493         t_blen = fsp->max_payload;
 494         if (lp->seq_offload) {
 495                 t_blen = min(seq_blen, (size_t)lp->lso_max);
 496                 FC_DEBUG_FCP("fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
 497                            fsp, seq_blen, lp->lso_max, t_blen);
 498         }
 499
 500         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
 501         if (t_blen > 512)
 502                 t_blen &= ~(512 - 1);   /* round down to block size */
 503         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);   /* won't go below 256 */
 504         sc = fsp->cmd;
 505
 506         remaining = seq_blen;
 507         fh_parm_offset = frame_offset = offset;
 508         tlen = 0;
 509         seq = lp->tt.seq_start_next(seq);
 510         f_ctl = FC_FC_REL_OFF;
 511         WARN_ON(!seq);
 512
 513         /*
 514          * If a get_page()/put_page() will fail, don't use sg lists
 515          * in the fc_frame structure.
 516          *
 517          * The put_page() may be long after the I/O has completed
 518          * in the case of FCoE, since the network driver does it
 519          * via free_skb().  See the test in free_pages_check().
 520          *
 521          * Test this case with 'dd </dev/zero >/dev/st0 bs=64k'.
 522          */
 523         if (using_sg) {
 524                 for (sg = scsi_sglist(sc); sg; sg = sg_next(sg)) {
 525                         if (page_count(sg_page(sg)) == 0 ||
 526                             (sg_page(sg)->flags & (1 << PG_lru |
 527                                                    1 << PG_private |
 528                                                    1 << PG_locked |
 529                                                    1 << PG_active |
 530                                                    1 << PG_slab |
 531                                                    1 << PG_swapcache |
 532                                                    1 << PG_writeback |
 533                                                    1 << PG_reserved |
 534                                                    1 << PG_buddy))) {
 535                                 using_sg = 0;
 536                                 break;
 537                         }
 538                 }
 539         }
 540         sg = scsi_sglist(sc);
 541
 542         while (remaining > 0 && sg) {
 543                 if (offset >= sg->length) {
 544                         offset -= sg->length;
 545                         sg = sg_next(sg);
 546                         continue;
 547                 }
 548                 if (!fp) {
 549                         tlen = min(t_blen, remaining);
 550
 551                         /*
 552                          * TODO.  Temporary workaround.  fc_seq_send() can't
 553                          * handle odd lengths in non-linear skbs.
 554                          * This will be the final fragment only.
 555                          */
 556                         if (tlen % 4)
 557                                 using_sg = 0;
 558                         if (using_sg) {
 559                                 fp = _fc_frame_alloc(lp, 0);
 560                                 if (!fp)
 561                                         return -ENOMEM;
 562                         } else {
 563                                 fp = fc_frame_alloc(lp, tlen);
 564                                 if (!fp)
 565                                         return -ENOMEM;
 566
 567                                 data = (void *)(fr_hdr(fp)) +
 568                                         sizeof(struct fc_frame_header);
 569                         }
 570                         fh_parm_offset = frame_offset;
 571                         fr_max_payload(fp) = fsp->max_payload;
 572                 }
 573                 sg_bytes = min(tlen, sg->length - offset);
 574                 if (using_sg) {
 575                         WARN_ON(skb_shinfo(fp_skb(fp))->nr_frags >
 576                                 FC_FRAME_SG_LEN);
 577                         get_page(sg_page(sg));
 578                         skb_fill_page_desc(fp_skb(fp),
 579                                            skb_shinfo(fp_skb(fp))->nr_frags,
 580                                            sg_page(sg), sg->offset + offset,
 581                                            sg_bytes);
 582                         fp_skb(fp)->data_len += sg_bytes;
 583                         fr_len(fp) += sg_bytes;
 584                         fp_skb(fp)->truesize += PAGE_SIZE;
 585                 } else {
 586                         size_t off = offset + sg->offset;
 587
 588                         /*
 589                          * The scatterlist item may be bigger than PAGE_SIZE,
 590                          * but we must not cross pages inside the kmap.
 591                          */
 592                         sg_bytes = min(sg_bytes, (size_t) (PAGE_SIZE -
 593                                                            (off & ~PAGE_MASK)));
 594                         page_addr = kmap_atomic(sg_page(sg) +
 595                                                 (off >> PAGE_SHIFT),
 596                                                 KM_SOFTIRQ0);
 597                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 598                                sg_bytes);
 599                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
 600                         data += sg_bytes;
 601                 }
 602                 offset += sg_bytes;
 603                 frame_offset += sg_bytes;
 604                 tlen -= sg_bytes;
 605                 remaining -= sg_bytes;
 606
 607                 if (tlen)
 608                         continue;
 609
 610                 /*
 611                  * Send sequence with transfer sequence initiative in case
 612                  * this is last FCP frame of the sequence.
 613                  */
 614                 if (remaining == 0)
 615                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 616
 617                 ep = fc_seq_exch(seq);
 618                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 619                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
 620
 621                 /*
 622                  * send fragment using for a sequence.
 623                  */
 624                 error = lp->tt.seq_send(lp, seq, fp);
 625                 if (error) {
 626                         WARN_ON(1);             /* send error should be rare */
 627                         fc_fcp_retry_cmd(fsp);
 628                         return 0;
 629                 }
 630                 fp = NULL;
 631         }
 632         fsp->xfer_len += seq_blen;      /* premature count? */
 633         return 0;
 634 }
 635
 636 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 637 {
 638         int ba_done = 1;
 639         struct fc_ba_rjt *brp;
 640         struct fc_frame_header *fh;
 641
 642         fh = fc_frame_header_get(fp);
 643         switch (fh->fh_r_ctl) {
 644         case FC_RCTL_BA_ACC:
 645                 break;
 646         case FC_RCTL_BA_RJT:
 647                 brp = fc_frame_payload_get(fp, sizeof(*brp));
 648                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 649                         break;
 650                 /* fall thru */
 651         default:
 652                 /*
 653                  * we will let the command timeout
 654                  * and scsi-ml recover in this case,
 655                  * therefore cleared the ba_done flag.
 656                  */
 657                 ba_done = 0;
 658         }
 659
 660         if (ba_done) {
 661                 fsp->state |= FC_SRB_ABORTED;
 662                 fsp->state &= ~FC_SRB_ABORT_PENDING;
 663
 664                 if (fsp->wait_for_comp)
 665                         complete(&fsp->tm_done);
 666                 else
 667                         fc_fcp_complete_locked(fsp);
 668         }
 669 }
 670
 671 /**
 672  * fc_fcp_reduce_can_queue() - drop can_queue
 673  * @lp: lport to drop queueing for
 674  *
 675  * If we are getting memory allocation failures, then we may
 676  * be trying to execute too many commands. We let the running
 677  * commands complete or timeout, then try again with a reduced
 678  * can_queue. Eventually we will hit the point where we run
 679  * on all reserved structs.
 680  */
 681 static void fc_fcp_reduce_can_queue(struct fc_lport *lp)
 682 {
 683         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 684         unsigned long flags;
 685         int can_queue;
 686
 687         spin_lock_irqsave(lp->host->host_lock, flags);
 688         if (si->throttled)
 689                 goto done;
 690         si->throttled = 1;
 691
 692         can_queue = lp->host->can_queue;
 693         can_queue >>= 1;
 694         if (!can_queue)
 695                 can_queue = 1;
 696         lp->host->can_queue = can_queue;
 697         shost_printk(KERN_ERR, lp->host, "Could not allocate frame.\n"
 698                      "Reducing can_queue to %d.\n", can_queue);
 699 done:
 700         spin_unlock_irqrestore(lp->host->host_lock, flags);
 701 }
 702
 703 /**
 704  * fc_fcp_recv() - Reveive FCP frames
 705  * @seq: The sequence the frame is on
 706  * @fp: The FC frame
 707  * @arg: The related FCP packet
 708  *
 709  * Return   : None
 710  * Context  : called from Soft IRQ context
 711  *            can not called holding list lock
 712  */
 713 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 714 {
 715         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 716         struct fc_lport *lp;
 717         struct fc_frame_header *fh;
 718         struct fcp_txrdy *dd;
 719         u8 r_ctl;
 720         int rc = 0;
 721
 722         if (IS_ERR(fp))
 723                 goto errout;
 724
 725         fh = fc_frame_header_get(fp);
 726         r_ctl = fh->fh_r_ctl;
 727         lp = fsp->lp;
 728
 729         if (!(lp->state & LPORT_ST_READY))
 730                 goto out;
 731         if (fc_fcp_lock_pkt(fsp))
 732                 goto out;
 733         fsp->last_pkt_time = jiffies;
 734
 735         if (fh->fh_type == FC_TYPE_BLS) {
 736                 fc_fcp_abts_resp(fsp, fp);
 737                 goto unlock;
 738         }
 739
 740         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
 741                 goto unlock;
 742
 743         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 744                 /*
 745                  * received XFER RDY from the target
 746                  * need to send data to the target
 747                  */
 748                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 749                 dd = fc_frame_payload_get(fp, sizeof(*dd));
 750                 WARN_ON(!dd);
 751
 752                 rc = fc_fcp_send_data(fsp, seq,
 753                                       (size_t) ntohl(dd->ft_data_ro),
 754                                       (size_t) ntohl(dd->ft_burst_len));
 755                 if (!rc)
 756                         seq->rec_data = fsp->xfer_len;
 757                 else if (rc == -ENOMEM)
 758                         fsp->state |= FC_SRB_NOMEM;
 759         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 760                 /*
 761                  * received a DATA frame
 762                  * next we will copy the data to the system buffer
 763                  */
 764                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
 765                 fc_fcp_recv_data(fsp, fp);
 766                 seq->rec_data = fsp->xfer_contig_end;
 767         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 768                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 769
 770                 fc_fcp_resp(fsp, fp);
 771         } else {
 772                 FC_DBG("unexpected frame.  r_ctl %x\n", r_ctl);
 773         }
 774 unlock:
 775         fc_fcp_unlock_pkt(fsp);
 776 out:
 777         fc_frame_free(fp);
 778 errout:
 779         if (IS_ERR(fp))
 780                 fc_fcp_error(fsp, fp);
 781         else if (rc == -ENOMEM)
 782                 fc_fcp_reduce_can_queue(lp);
 783 }
 784
 785 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 786 {
 787         struct fc_frame_header *fh;
 788         struct fcp_resp *fc_rp;
 789         struct fcp_resp_ext *rp_ex;
 790         struct fcp_resp_rsp_info *fc_rp_info;
 791         u32 plen;
 792         u32 expected_len;
 793         u32 respl = 0;
 794         u32 snsl = 0;
 795         u8 flags = 0;
 796
 797         plen = fr_len(fp);
 798         fh = (struct fc_frame_header *)fr_hdr(fp);
 799         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 800                 goto len_err;
 801         plen -= sizeof(*fh);
 802         fc_rp = (struct fcp_resp *)(fh + 1);
 803         fsp->cdb_status = fc_rp->fr_status;
 804         flags = fc_rp->fr_flags;
 805         fsp->scsi_comp_flags = flags;
 806         expected_len = fsp->data_len;
 807
 808         /* if ddp, update xfer len */
 809         fc_fcp_ddp_done(fsp);
 810
 811         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 812                 rp_ex = (void *)(fc_rp + 1);
 813                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 814                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 815                                 goto len_err;
 816                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 817                         if (flags & FCP_RSP_LEN_VAL) {
 818                                 respl = ntohl(rp_ex->fr_rsp_len);
 819                                 if (respl != sizeof(*fc_rp_info))
 820                                         goto len_err;
 821                                 if (fsp->wait_for_comp) {
 822                                         /* Abuse cdb_status for rsp code */
 823                                         fsp->cdb_status = fc_rp_info->rsp_code;
 824                                         complete(&fsp->tm_done);
 825                                         /*
 826                                          * tmfs will not have any scsi cmd so
 827                                          * exit here
 828                                          */
 829                                         return;
 830                                 } else
 831                                         goto err;
 832                         }
 833                         if (flags & FCP_SNS_LEN_VAL) {
 834                                 snsl = ntohl(rp_ex->fr_sns_len);
 835                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
 836                                         snsl = SCSI_SENSE_BUFFERSIZE;
 837                                 memcpy(fsp->cmd->sense_buffer,
 838                                        (char *)fc_rp_info + respl, snsl);
 839                         }
 840                 }
 841                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 842                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 843                                 goto len_err;
 844                         if (flags & FCP_RESID_UNDER) {
 845                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 846                                 /*
 847                                  * The cmnd->underflow is the minimum number of
 848                                  * bytes that must be transfered for this
 849                                  * command.  Provided a sense condition is not
 850                                  * present, make sure the actual amount
 851                                  * transferred is at least the underflow value
 852                                  * or fail.
 853                                  */
 854                                 if (!(flags & FCP_SNS_LEN_VAL) &&
 855                                     (fc_rp->fr_status == 0) &&
 856                                     (scsi_bufflen(fsp->cmd) -
 857                                      fsp->scsi_resid) < fsp->cmd->underflow)
 858                                         goto err;
 859                                 expected_len -= fsp->scsi_resid;
 860                         } else {
 861                                 fsp->status_code = FC_ERROR;
 862                         }
 863                 }
 864         }
 865         fsp->state |= FC_SRB_RCV_STATUS;
 866
 867         /*
 868          * Check for missing or extra data frames.
 869          */
 870         if (unlikely(fsp->xfer_len != expected_len)) {
 871                 if (fsp->xfer_len < expected_len) {
 872                         /*
 873                          * Some data may be queued locally,
 874                          * Wait a at least one jiffy to see if it is delivered.
 875                          * If this expires without data, we may do SRR.
 876                          */
 877                         fc_fcp_timer_set(fsp, 2);
 878                         return;
 879                 }
 880                 fsp->status_code = FC_DATA_OVRRUN;
 881                 FC_DBG("tgt %6x xfer len %zx greater than expected len %x. "
 882                        "data len %x\n",
 883                        fsp->rport->port_id,
 884                        fsp->xfer_len, expected_len, fsp->data_len);
 885         }
 886         fc_fcp_complete_locked(fsp);
 887         return;
 888
 889 len_err:
 890         FC_DBG("short FCP response. flags 0x%x len %u respl %u snsl %u\n",
 891                flags, fr_len(fp), respl, snsl);
 892 err:
 893         fsp->status_code = FC_ERROR;
 894         fc_fcp_complete_locked(fsp);
 895 }
 896
 897 /**
 898  * fc_fcp_complete_locked() - complete processing of a fcp packet
 899  * @fsp:        fcp packet
 900  *
 901  * This function may sleep if a timer is pending. The packet lock must be
 902  * held, and the host lock must not be held.
 903  */
 904 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 905 {
 906         struct fc_lport *lp = fsp->lp;
 907         struct fc_seq *seq;
 908         struct fc_exch *ep;
 909         u32 f_ctl;
 910
 911         if (fsp->state & FC_SRB_ABORT_PENDING)
 912                 return;
 913
 914         if (fsp->state & FC_SRB_ABORTED) {
 915                 if (!fsp->status_code)
 916                         fsp->status_code = FC_CMD_ABORTED;
 917         } else {
 918                 /*
 919                  * Test for transport underrun, independent of response
 920                  * underrun status.
 921                  */
 922                 if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
 923                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
 924                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
 925                         fsp->status_code = FC_DATA_UNDRUN;
 926                         fsp->io_status = 0;
 927                 }
 928         }
 929
 930         seq = fsp->seq_ptr;
 931         if (seq) {
 932                 fsp->seq_ptr = NULL;
 933                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
 934                         struct fc_frame *conf_frame;
 935                         struct fc_seq *csp;
 936
 937                         csp = lp->tt.seq_start_next(seq);
 938                         conf_frame = fc_frame_alloc(fsp->lp, 0);
 939                         if (conf_frame) {
 940                                 f_ctl = FC_FC_SEQ_INIT;
 941                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
 942                                 ep = fc_seq_exch(seq);
 943                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
 944                                                ep->did, ep->sid,
 945                                                FC_TYPE_FCP, f_ctl, 0);
 946                                 lp->tt.seq_send(lp, csp, conf_frame);
 947                         }
 948                 }
 949                 lp->tt.exch_done(seq);
 950         }
 951         fc_io_compl(fsp);
 952 }
 953
 954 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
 955 {
 956         struct fc_lport *lp = fsp->lp;
 957
 958         if (fsp->seq_ptr) {
 959                 lp->tt.exch_done(fsp->seq_ptr);
 960                 fsp->seq_ptr = NULL;
 961         }
 962         fsp->status_code = error;
 963 }
 964
 965 /**
 966  * fc_fcp_cleanup_each_cmd() - Cleanup active commads
 967  * @lp:         logical port
 968  * @id:         target id
 969  * @lun:        lun
 970  * @error:      fsp status code
 971  *
 972  * If lun or id is -1, they are ignored.
 973  */
 974 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lp, unsigned int id,
 975                                     unsigned int lun, int error)
 976 {
 977         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 978         struct fc_fcp_pkt *fsp;
 979         struct scsi_cmnd *sc_cmd;
 980         unsigned long flags;
 981
 982         spin_lock_irqsave(lp->host->host_lock, flags);
 983 restart:
 984         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
 985                 sc_cmd = fsp->cmd;
 986                 if (id != -1 && scmd_id(sc_cmd) != id)
 987                         continue;
 988
 989                 if (lun != -1 && sc_cmd->device->lun != lun)
 990                         continue;
 991
 992                 fc_fcp_pkt_hold(fsp);
 993                 spin_unlock_irqrestore(lp->host->host_lock, flags);
 994
 995                 if (!fc_fcp_lock_pkt(fsp)) {
 996                         fc_fcp_cleanup_cmd(fsp, error);
 997                         fc_io_compl(fsp);
 998                         fc_fcp_unlock_pkt(fsp);
 999                 }
1000
1001                 fc_fcp_pkt_release(fsp);
1002                 spin_lock_irqsave(lp->host->host_lock, flags);
1003                 /*
1004                  * while we dropped the lock multiple pkts could
1005                  * have been released, so we have to start over.
1006                  */
1007                 goto restart;
1008         }
1009         spin_unlock_irqrestore(lp->host->host_lock, flags);
1010 }
1011
1012 static void fc_fcp_abort_io(struct fc_lport *lp)
1013 {
1014         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_HRD_ERROR);
1015 }
1016
1017 /**
1018  * fc_fcp_pkt_send() - send a fcp packet to the lower level.
1019  * @lp:         fc lport
1020  * @fsp:        fc packet.
1021  *
1022  * This is called by upper layer protocol.
1023  * Return   : zero for success and -1 for failure
1024  * Context  : called from queuecommand which can be called from process
1025  *            or scsi soft irq.
1026  * Locks    : called with the host lock and irqs disabled.
1027  */
1028 static int fc_fcp_pkt_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1029 {
1030         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
1031         int rc;
1032
1033         fsp->cmd->SCp.ptr = (char *)fsp;
1034         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1035         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1036
1037         int_to_scsilun(fsp->cmd->device->lun,
1038                        (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1039         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1040         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1041
1042         spin_unlock_irq(lp->host->host_lock);
1043         rc = lp->tt.fcp_cmd_send(lp, fsp, fc_fcp_recv);
1044         spin_lock_irq(lp->host->host_lock);
1045         if (rc)
1046                 list_del(&fsp->list);
1047
1048         return rc;
1049 }
1050
1051 static int fc_fcp_cmd_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1052                            void (*resp)(struct fc_seq *,
1053                                         struct fc_frame *fp,
1054                                         void *arg))
1055 {
1056         struct fc_frame *fp;
1057         struct fc_seq *seq;
1058         struct fc_rport *rport;
1059         struct fc_rport_libfc_priv *rp;
1060         const size_t len = sizeof(fsp->cdb_cmd);
1061         int rc = 0;
1062
1063         if (fc_fcp_lock_pkt(fsp))
1064                 return 0;
1065
1066         fp = fc_frame_alloc(lp, sizeof(fsp->cdb_cmd));
1067         if (!fp) {
1068                 rc = -1;
1069                 goto unlock;
1070         }
1071
1072         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1073         fr_fsp(fp) = fsp;
1074         rport = fsp->rport;
1075         fsp->max_payload = rport->maxframe_size;
1076         rp = rport->dd_data;
1077
1078         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1079                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1080                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1081
1082         seq = lp->tt.exch_seq_send(lp, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1083         if (!seq) {
1084                 fc_frame_free(fp);
1085                 rc = -1;
1086                 goto unlock;
1087         }
1088         fsp->last_pkt_time = jiffies;
1089         fsp->seq_ptr = seq;
1090         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1091
1092         setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1093         fc_fcp_timer_set(fsp,
1094                          (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
1095                          FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
1096 unlock:
1097         fc_fcp_unlock_pkt(fsp);
1098         return rc;
1099 }
1100
1101 /*
1102  * transport error handler
1103  */
1104 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1105 {
1106         int error = PTR_ERR(fp);
1107
1108         if (fc_fcp_lock_pkt(fsp))
1109                 return;
1110
1111         switch (error) {
1112         case -FC_EX_CLOSED:
1113                 fc_fcp_retry_cmd(fsp);
1114                 goto unlock;
1115         default:
1116                 FC_DBG("unknown error %ld\n", PTR_ERR(fp));
1117         }
1118         /*
1119          * clear abort pending, because the lower layer
1120          * decided to force completion.
1121          */
1122         fsp->state &= ~FC_SRB_ABORT_PENDING;
1123         fsp->status_code = FC_CMD_PLOGO;
1124         fc_fcp_complete_locked(fsp);
1125 unlock:
1126         fc_fcp_unlock_pkt(fsp);
1127 }
1128
1129 /*
1130  * Scsi abort handler- calls to send an abort
1131  * and then wait for abort completion
1132  */
1133 static int fc_fcp_pkt_abort(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1134 {
1135         int rc = FAILED;
1136
1137         if (fc_fcp_send_abort(fsp))
1138                 return FAILED;
1139
1140         init_completion(&fsp->tm_done);
1141         fsp->wait_for_comp = 1;
1142
1143         spin_unlock_bh(&fsp->scsi_pkt_lock);
1144         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1145         spin_lock_bh(&fsp->scsi_pkt_lock);
1146         fsp->wait_for_comp = 0;
1147
1148         if (!rc) {
1149                 FC_DBG("target abort cmd  failed\n");
1150                 rc = FAILED;
1151         } else if (fsp->state & FC_SRB_ABORTED) {
1152                 FC_DBG("target abort cmd  passed\n");
1153                 rc = SUCCESS;
1154                 fc_fcp_complete_locked(fsp);
1155         }
1156
1157         return rc;
1158 }
1159
1160 /*
1161  * Retry LUN reset after resource allocation failed.
1162  */
1163 static void fc_lun_reset_send(unsigned long data)
1164 {
1165         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1166         struct fc_lport *lp = fsp->lp;
1167         if (lp->tt.fcp_cmd_send(lp, fsp, fc_tm_done)) {
1168                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1169                         return;
1170                 if (fc_fcp_lock_pkt(fsp))
1171                         return;
1172                 setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1173                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1174                 fc_fcp_unlock_pkt(fsp);
1175         }
1176 }
1177
1178 /*
1179  * Scsi device reset handler- send a LUN RESET to the device
1180  * and wait for reset reply
1181  */
1182 static int fc_lun_reset(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1183                         unsigned int id, unsigned int lun)
1184 {
1185         int rc;
1186
1187         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1188         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1189         int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1190
1191         fsp->wait_for_comp = 1;
1192         init_completion(&fsp->tm_done);
1193
1194         fc_lun_reset_send((unsigned long)fsp);
1195
1196         /*
1197          * wait for completion of reset
1198          * after that make sure all commands are terminated
1199          */
1200         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1201
1202         spin_lock_bh(&fsp->scsi_pkt_lock);
1203         fsp->state |= FC_SRB_COMPL;
1204         spin_unlock_bh(&fsp->scsi_pkt_lock);
1205
1206         del_timer_sync(&fsp->timer);
1207
1208         spin_lock_bh(&fsp->scsi_pkt_lock);
1209         if (fsp->seq_ptr) {
1210                 lp->tt.exch_done(fsp->seq_ptr);
1211                 fsp->seq_ptr = NULL;
1212         }
1213         fsp->wait_for_comp = 0;
1214         spin_unlock_bh(&fsp->scsi_pkt_lock);
1215
1216         if (!rc) {
1217                 FC_DBG("lun reset failed\n");
1218                 return FAILED;
1219         }
1220
1221         /* cdb_status holds the tmf's rsp code */
1222         if (fsp->cdb_status != FCP_TMF_CMPL)
1223                 return FAILED;
1224
1225         FC_DBG("lun reset to lun %u completed\n", lun);
1226         fc_fcp_cleanup_each_cmd(lp, id, lun, FC_CMD_ABORTED);
1227         return SUCCESS;
1228 }
1229
1230 /*
1231  * Task Managment response handler
1232  */
1233 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1234 {
1235         struct fc_fcp_pkt *fsp = arg;
1236         struct fc_frame_header *fh;
1237
1238         if (IS_ERR(fp)) {
1239                 /*
1240                  * If there is an error just let it timeout or wait
1241                  * for TMF to be aborted if it timedout.
1242                  *
1243                  * scsi-eh will escalate for when either happens.
1244                  */
1245                 return;
1246         }
1247
1248         if (fc_fcp_lock_pkt(fsp))
1249                 return;
1250
1251         /*
1252          * raced with eh timeout handler.
1253          */
1254         if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1255                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1256                 return;
1257         }
1258
1259         fh = fc_frame_header_get(fp);
1260         if (fh->fh_type != FC_TYPE_BLS)
1261                 fc_fcp_resp(fsp, fp);
1262         fsp->seq_ptr = NULL;
1263         fsp->lp->tt.exch_done(seq);
1264         fc_frame_free(fp);
1265         fc_fcp_unlock_pkt(fsp);
1266 }
1267
1268 static void fc_fcp_cleanup(struct fc_lport *lp)
1269 {
1270         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_ERROR);
1271 }
1272
1273 /*
1274  * fc_fcp_timeout: called by OS timer function.
1275  *
1276  * The timer has been inactivated and must be reactivated if desired
1277  * using fc_fcp_timer_set().
1278  *
1279  * Algorithm:
1280  *
1281  * If REC is supported, just issue it, and return.  The REC exchange will
1282  * complete or time out, and recovery can continue at that point.
1283  *
1284  * Otherwise, if the response has been received without all the data,
1285  * it has been ER_TIMEOUT since the response was received.
1286  *
1287  * If the response has not been received,
1288  * we see if data was received recently.  If it has been, we continue waiting,
1289  * otherwise, we abort the command.
1290  */
1291 static void fc_fcp_timeout(unsigned long data)
1292 {
1293         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1294         struct fc_rport *rport = fsp->rport;
1295         struct fc_rport_libfc_priv *rp = rport->dd_data;
1296
1297         if (fc_fcp_lock_pkt(fsp))
1298                 return;
1299
1300         if (fsp->cdb_cmd.fc_tm_flags)
1301                 goto unlock;
1302
1303         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1304
1305         if (rp->flags & FC_RP_FLAGS_REC_SUPPORTED)
1306                 fc_fcp_rec(fsp);
1307         else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
1308                                jiffies))
1309                 fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1310         else if (fsp->state & FC_SRB_RCV_STATUS)
1311                 fc_fcp_complete_locked(fsp);
1312         else
1313                 fc_timeout_error(fsp);
1314         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1315 unlock:
1316         fc_fcp_unlock_pkt(fsp);
1317 }
1318
1319 /*
1320  * Send a REC ELS request
1321  */
1322 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1323 {
1324         struct fc_lport *lp;
1325         struct fc_frame *fp;
1326         struct fc_rport *rport;
1327         struct fc_rport_libfc_priv *rp;
1328
1329         lp = fsp->lp;
1330         rport = fsp->rport;
1331         rp = rport->dd_data;
1332         if (!fsp->seq_ptr || rp->rp_state != RPORT_ST_READY) {
1333                 fsp->status_code = FC_HRD_ERROR;
1334                 fsp->io_status = 0;
1335                 fc_fcp_complete_locked(fsp);
1336                 return;
1337         }
1338         fp = fc_frame_alloc(lp, sizeof(struct fc_els_rec));
1339         if (!fp)
1340                 goto retry;
1341
1342         fr_seq(fp) = fsp->seq_ptr;
1343         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1344                        fc_host_port_id(rp->local_port->host), FC_TYPE_ELS,
1345                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1346         if (lp->tt.elsct_send(lp, rport, fp, ELS_REC, fc_fcp_rec_resp,
1347                               fsp, jiffies_to_msecs(FC_SCSI_REC_TOV))) {
1348                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1349                 return;
1350         }
1351         fc_frame_free(fp);
1352 retry:
1353         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1354                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1355         else
1356                 fc_timeout_error(fsp);
1357 }
1358
1359 /*
1360  * Receive handler for REC ELS frame
1361  * if it is a reject then let the scsi layer to handle
1362  * the timeout. if it is a LS_ACC then if the io was not completed
1363  * then set the timeout and return otherwise complete the exchange
1364  * and tell the scsi layer to restart the I/O.
1365  */
1366 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1367 {
1368         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1369         struct fc_els_rec_acc *recp;
1370         struct fc_els_ls_rjt *rjt;
1371         u32 e_stat;
1372         u8 opcode;
1373         u32 offset;
1374         enum dma_data_direction data_dir;
1375         enum fc_rctl r_ctl;
1376         struct fc_rport_libfc_priv *rp;
1377
1378         if (IS_ERR(fp)) {
1379                 fc_fcp_rec_error(fsp, fp);
1380                 return;
1381         }
1382
1383         if (fc_fcp_lock_pkt(fsp))
1384                 goto out;
1385
1386         fsp->recov_retry = 0;
1387         opcode = fc_frame_payload_op(fp);
1388         if (opcode == ELS_LS_RJT) {
1389                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1390                 switch (rjt->er_reason) {
1391                 default:
1392                         FC_DEBUG_FCP("device %x unexpected REC reject "
1393                                      "reason %d expl %d\n",
1394                                      fsp->rport->port_id, rjt->er_reason,
1395                                      rjt->er_explan);
1396                         /* fall through */
1397                 case ELS_RJT_UNSUP:
1398                         FC_DEBUG_FCP("device does not support REC\n");
1399                         rp = fsp->rport->dd_data;
1400                         /*
1401                          * if we do not spport RECs or got some bogus
1402                          * reason then resetup timer so we check for
1403                          * making progress.
1404                          */
1405                         rp->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1406                         fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1407                         break;
1408                 case ELS_RJT_LOGIC:
1409                 case ELS_RJT_UNAB:
1410                         /*
1411                          * If no data transfer, the command frame got dropped
1412                          * so we just retry.  If data was transferred, we
1413                          * lost the response but the target has no record,
1414                          * so we abort and retry.
1415                          */
1416                         if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1417                             fsp->xfer_len == 0) {
1418                                 fc_fcp_retry_cmd(fsp);
1419                                 break;
1420                         }
1421                         fc_timeout_error(fsp);
1422                         break;
1423                 }
1424         } else if (opcode == ELS_LS_ACC) {
1425                 if (fsp->state & FC_SRB_ABORTED)
1426                         goto unlock_out;
1427
1428                 data_dir = fsp->cmd->sc_data_direction;
1429                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1430                 offset = ntohl(recp->reca_fc4value);
1431                 e_stat = ntohl(recp->reca_e_stat);
1432
1433                 if (e_stat & ESB_ST_COMPLETE) {
1434
1435                         /*
1436                          * The exchange is complete.
1437                          *
1438                          * For output, we must've lost the response.
1439                          * For input, all data must've been sent.
1440                          * We lost may have lost the response
1441                          * (and a confirmation was requested) and maybe
1442                          * some data.
1443                          *
1444                          * If all data received, send SRR
1445                          * asking for response.  If partial data received,
1446                          * or gaps, SRR requests data at start of gap.
1447                          * Recovery via SRR relies on in-order-delivery.
1448                          */
1449                         if (data_dir == DMA_TO_DEVICE) {
1450                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1451                         } else if (fsp->xfer_contig_end == offset) {
1452                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1453                         } else {
1454                                 offset = fsp->xfer_contig_end;
1455                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1456                         }
1457                         fc_fcp_srr(fsp, r_ctl, offset);
1458                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1459
1460                         /*
1461                          * The remote port has the initiative, so just
1462                          * keep waiting for it to complete.
1463                          */
1464                         fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1465                 } else {
1466
1467                         /*
1468                          * The exchange is incomplete, we have seq. initiative.
1469                          * Lost response with requested confirmation,
1470                          * lost confirmation, lost transfer ready or
1471                          * lost write data.
1472                          *
1473                          * For output, if not all data was received, ask
1474                          * for transfer ready to be repeated.
1475                          *
1476                          * If we received or sent all the data, send SRR to
1477                          * request response.
1478                          *
1479                          * If we lost a response, we may have lost some read
1480                          * data as well.
1481                          */
1482                         r_ctl = FC_RCTL_DD_SOL_DATA;
1483                         if (data_dir == DMA_TO_DEVICE) {
1484                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1485                                 if (offset < fsp->data_len)
1486                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1487                         } else if (offset == fsp->xfer_contig_end) {
1488                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1489                         } else if (fsp->xfer_contig_end < offset) {
1490                                 offset = fsp->xfer_contig_end;
1491                         }
1492                         fc_fcp_srr(fsp, r_ctl, offset);
1493                 }
1494         }
1495 unlock_out:
1496         fc_fcp_unlock_pkt(fsp);
1497 out:
1498         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1499         fc_frame_free(fp);
1500 }
1501
1502 /*
1503  * Handle error response or timeout for REC exchange.
1504  */
1505 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1506 {
1507         int error = PTR_ERR(fp);
1508
1509         if (fc_fcp_lock_pkt(fsp))
1510                 goto out;
1511
1512         switch (error) {
1513         case -FC_EX_CLOSED:
1514                 fc_fcp_retry_cmd(fsp);
1515                 break;
1516
1517         default:
1518                 FC_DBG("REC %p fid %x error unexpected error %d\n",
1519                        fsp, fsp->rport->port_id, error);
1520                 fsp->status_code = FC_CMD_PLOGO;
1521                 /* fall through */
1522
1523         case -FC_EX_TIMEOUT:
1524                 /*
1525                  * Assume REC or LS_ACC was lost.
1526                  * The exchange manager will have aborted REC, so retry.
1527                  */
1528                 FC_DBG("REC fid %x error error %d retry %d/%d\n",
1529                        fsp->rport->port_id, error, fsp->recov_retry,
1530                        FC_MAX_RECOV_RETRY);
1531                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1532                         fc_fcp_rec(fsp);
1533                 else
1534                         fc_timeout_error(fsp);
1535                 break;
1536         }
1537         fc_fcp_unlock_pkt(fsp);
1538 out:
1539         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1540 }
1541
1542 /*
1543  * Time out error routine:
1544  * abort's the I/O close the exchange and
1545  * send completion notification to scsi layer
1546  */
1547 static void fc_timeout_error(struct fc_fcp_pkt *fsp)
1548 {
1549         fsp->status_code = FC_CMD_TIME_OUT;
1550         fsp->cdb_status = 0;
1551         fsp->io_status = 0;
1552         /*
1553          * if this fails then we let the scsi command timer fire and
1554          * scsi-ml escalate.
1555          */
1556         fc_fcp_send_abort(fsp);
1557 }
1558
1559 /*
1560  * Sequence retransmission request.
1561  * This is called after receiving status but insufficient data, or
1562  * when expecting status but the request has timed out.
1563  */
1564 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1565 {
1566         struct fc_lport *lp = fsp->lp;
1567         struct fc_rport *rport;
1568         struct fc_rport_libfc_priv *rp;
1569         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1570         struct fc_seq *seq;
1571         struct fcp_srr *srr;
1572         struct fc_frame *fp;
1573         u8 cdb_op;
1574
1575         rport = fsp->rport;
1576         rp = rport->dd_data;
1577         cdb_op = fsp->cdb_cmd.fc_cdb[0];
1578
1579         if (!(rp->flags & FC_RP_FLAGS_RETRY) || rp->rp_state != RPORT_ST_READY)
1580                 goto retry;                     /* shouldn't happen */
1581         fp = fc_frame_alloc(lp, sizeof(*srr));
1582         if (!fp)
1583                 goto retry;
1584
1585         srr = fc_frame_payload_get(fp, sizeof(*srr));
1586         memset(srr, 0, sizeof(*srr));
1587         srr->srr_op = ELS_SRR;
1588         srr->srr_ox_id = htons(ep->oxid);
1589         srr->srr_rx_id = htons(ep->rxid);
1590         srr->srr_r_ctl = r_ctl;
1591         srr->srr_rel_off = htonl(offset);
1592
1593         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1594                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1595                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1596
1597         seq = lp->tt.exch_seq_send(lp, fp, fc_fcp_srr_resp, NULL,
1598                                    fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
1599         if (!seq) {
1600                 fc_frame_free(fp);
1601                 goto retry;
1602         }
1603         fsp->recov_seq = seq;
1604         fsp->xfer_len = offset;
1605         fsp->xfer_contig_end = offset;
1606         fsp->state &= ~FC_SRB_RCV_STATUS;
1607         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1608         return;
1609 retry:
1610         fc_fcp_retry_cmd(fsp);
1611 }
1612
1613 /*
1614  * Handle response from SRR.
1615  */
1616 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1617 {
1618         struct fc_fcp_pkt *fsp = arg;
1619         struct fc_frame_header *fh;
1620
1621         if (IS_ERR(fp)) {
1622                 fc_fcp_srr_error(fsp, fp);
1623                 return;
1624         }
1625
1626         if (fc_fcp_lock_pkt(fsp))
1627                 goto out;
1628
1629         fh = fc_frame_header_get(fp);
1630         /*
1631          * BUG? fc_fcp_srr_error calls exch_done which would release
1632          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1633          * then fc_exch_timeout would be sending an abort. The exch_done
1634          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1635          * an abort response though.
1636          */
1637         if (fh->fh_type == FC_TYPE_BLS) {
1638                 fc_fcp_unlock_pkt(fsp);
1639                 return;
1640         }
1641
1642         fsp->recov_seq = NULL;
1643         switch (fc_frame_payload_op(fp)) {
1644         case ELS_LS_ACC:
1645                 fsp->recov_retry = 0;
1646                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1647                 break;
1648         case ELS_LS_RJT:
1649         default:
1650                 fc_timeout_error(fsp);
1651                 break;
1652         }
1653         fc_fcp_unlock_pkt(fsp);
1654         fsp->lp->tt.exch_done(seq);
1655 out:
1656         fc_frame_free(fp);
1657         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1658 }
1659
1660 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1661 {
1662         if (fc_fcp_lock_pkt(fsp))
1663                 goto out;
1664         fsp->lp->tt.exch_done(fsp->recov_seq);
1665         fsp->recov_seq = NULL;
1666         switch (PTR_ERR(fp)) {
1667         case -FC_EX_TIMEOUT:
1668                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1669                         fc_fcp_rec(fsp);
1670                 else
1671                         fc_timeout_error(fsp);
1672                 break;
1673         case -FC_EX_CLOSED:                     /* e.g., link failure */
1674                 /* fall through */
1675         default:
1676                 fc_fcp_retry_cmd(fsp);
1677                 break;
1678         }
1679         fc_fcp_unlock_pkt(fsp);
1680 out:
1681         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1682 }
1683
1684 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp)
1685 {
1686         /* lock ? */
1687         return (lp->state == LPORT_ST_READY) && lp->link_up && !lp->qfull;
1688 }
1689
1690 /**
1691  * fc_queuecommand - The queuecommand function of the scsi template
1692  * @cmd:        struct scsi_cmnd to be executed
1693  * @done:       Callback function to be called when cmd is completed
1694  *
1695  * this is the i/o strategy routine, called by the scsi layer
1696  * this routine is called with holding the host_lock.
1697  */
1698 int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1699 {
1700         struct fc_lport *lp;
1701         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1702         struct fc_fcp_pkt *fsp;
1703         struct fc_rport_libfc_priv *rp;
1704         int rval;
1705         int rc = 0;
1706         struct fcoe_dev_stats *stats;
1707
1708         lp = shost_priv(sc_cmd->device->host);
1709
1710         rval = fc_remote_port_chkready(rport);
1711         if (rval) {
1712                 sc_cmd->result = rval;
1713                 done(sc_cmd);
1714                 goto out;
1715         }
1716
1717         if (!*(struct fc_remote_port **)rport->dd_data) {
1718                 /*
1719                  * rport is transitioning from blocked/deleted to
1720                  * online
1721                  */
1722                 sc_cmd->result = DID_IMM_RETRY << 16;
1723                 done(sc_cmd);
1724                 goto out;
1725         }
1726
1727         rp = rport->dd_data;
1728
1729         if (!fc_fcp_lport_queue_ready(lp)) {
1730                 rc = SCSI_MLQUEUE_HOST_BUSY;
1731                 goto out;
1732         }
1733
1734         fsp = fc_fcp_pkt_alloc(lp, GFP_ATOMIC);
1735         if (fsp == NULL) {
1736                 rc = SCSI_MLQUEUE_HOST_BUSY;
1737                 goto out;
1738         }
1739
1740         /*
1741          * build the libfc request pkt
1742          */
1743         fsp->cmd = sc_cmd;      /* save the cmd */
1744         fsp->lp = lp;           /* save the softc ptr */
1745         fsp->rport = rport;     /* set the remote port ptr */
1746         sc_cmd->scsi_done = done;
1747
1748         /*
1749          * set up the transfer length
1750          */
1751         fsp->data_len = scsi_bufflen(sc_cmd);
1752         fsp->xfer_len = 0;
1753
1754         /*
1755          * setup the data direction
1756          */
1757         stats = fc_lport_get_stats(lp);
1758         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1759                 fsp->req_flags = FC_SRB_READ;
1760                 stats->InputRequests++;
1761                 stats->InputMegabytes = fsp->data_len;
1762         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1763                 fsp->req_flags = FC_SRB_WRITE;
1764                 stats->OutputRequests++;
1765                 stats->OutputMegabytes = fsp->data_len;
1766         } else {
1767                 fsp->req_flags = 0;
1768                 stats->ControlRequests++;
1769         }
1770
1771         fsp->tgt_flags = rp->flags;
1772
1773         init_timer(&fsp->timer);
1774         fsp->timer.data = (unsigned long)fsp;
1775
1776         /*
1777          * send it to the lower layer
1778          * if we get -1 return then put the request in the pending
1779          * queue.
1780          */
1781         rval = fc_fcp_pkt_send(lp, fsp);
1782         if (rval != 0) {
1783                 fsp->state = FC_SRB_FREE;
1784                 fc_fcp_pkt_release(fsp);
1785                 rc = SCSI_MLQUEUE_HOST_BUSY;
1786         }
1787 out:
1788         return rc;
1789 }
1790 EXPORT_SYMBOL(fc_queuecommand);
1791
1792 /**
1793  * fc_io_compl() -  Handle responses for completed commands
1794  * @fsp:        scsi packet
1795  *
1796  * Translates a error to a Linux SCSI error.
1797  *
1798  * The fcp packet lock must be held when calling.
1799  */
1800 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1801 {
1802         struct fc_fcp_internal *si;
1803         struct scsi_cmnd *sc_cmd;
1804         struct fc_lport *lp;
1805         unsigned long flags;
1806
1807         /* release outstanding ddp context */
1808         fc_fcp_ddp_done(fsp);
1809
1810         fsp->state |= FC_SRB_COMPL;
1811         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1812                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1813                 del_timer_sync(&fsp->timer);
1814                 spin_lock_bh(&fsp->scsi_pkt_lock);
1815         }
1816
1817         lp = fsp->lp;
1818         si = fc_get_scsi_internal(lp);
1819         spin_lock_irqsave(lp->host->host_lock, flags);
1820         if (!fsp->cmd) {
1821                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1822                 return;
1823         }
1824
1825         /*
1826          * if a command timed out while we had to try and throttle IO
1827          * and it is now getting cleaned up, then we are about to
1828          * try again so clear the throttled flag incase we get more
1829          * time outs.
1830          */
1831         if (si->throttled && fsp->state & FC_SRB_NOMEM)
1832                 si->throttled = 0;
1833
1834         sc_cmd = fsp->cmd;
1835         fsp->cmd = NULL;
1836
1837         if (!sc_cmd->SCp.ptr) {
1838                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1839                 return;
1840         }
1841
1842         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1843         switch (fsp->status_code) {
1844         case FC_COMPLETE:
1845                 if (fsp->cdb_status == 0) {
1846                         /*
1847                          * good I/O status
1848                          */
1849                         sc_cmd->result = DID_OK << 16;
1850                         if (fsp->scsi_resid)
1851                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1852                 } else if (fsp->cdb_status == QUEUE_FULL) {
1853                         struct scsi_device *tmp_sdev;
1854                         struct scsi_device *sdev = sc_cmd->device;
1855
1856                         shost_for_each_device(tmp_sdev, sdev->host) {
1857                                 if (tmp_sdev->id != sdev->id)
1858                                         continue;
1859
1860                                 if (tmp_sdev->queue_depth > 1) {
1861                                         scsi_track_queue_full(tmp_sdev,
1862                                                               tmp_sdev->
1863                                                               queue_depth - 1);
1864                                 }
1865                         }
1866                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1867                 } else {
1868                         /*
1869                          * transport level I/O was ok but scsi
1870                          * has non zero status
1871                          */
1872                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1873                 }
1874                 break;
1875         case FC_ERROR:
1876                 sc_cmd->result = DID_ERROR << 16;
1877                 break;
1878         case FC_DATA_UNDRUN:
1879                 if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1880                         /*
1881                          * scsi status is good but transport level
1882                          * underrun.
1883                          */
1884                         sc_cmd->result = DID_OK << 16;
1885                 } else {
1886                         /*
1887                          * scsi got underrun, this is an error
1888                          */
1889                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1890                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1891                 }
1892                 break;
1893         case FC_DATA_OVRRUN:
1894                 /*
1895                  * overrun is an error
1896                  */
1897                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1898                 break;
1899         case FC_CMD_ABORTED:
1900                 sc_cmd->result = (DID_ABORT << 16) | fsp->io_status;
1901                 break;
1902         case FC_CMD_TIME_OUT:
1903                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1904                 break;
1905         case FC_CMD_RESET:
1906                 sc_cmd->result = (DID_RESET << 16);
1907                 break;
1908         case FC_HRD_ERROR:
1909                 sc_cmd->result = (DID_NO_CONNECT << 16);
1910                 break;
1911         default:
1912                 sc_cmd->result = (DID_ERROR << 16);
1913                 break;
1914         }
1915
1916         list_del(&fsp->list);
1917         sc_cmd->SCp.ptr = NULL;
1918         sc_cmd->scsi_done(sc_cmd);
1919         spin_unlock_irqrestore(lp->host->host_lock, flags);
1920
1921         /* release ref from initial allocation in queue command */
1922         fc_fcp_pkt_release(fsp);
1923 }
1924
1925 /**
1926  * fc_fcp_complete() - complete processing of a fcp packet
1927  * @fsp:        fcp packet
1928  *
1929  * This function may sleep if a fsp timer is pending.
1930  * The host lock must not be held by caller.
1931  */
1932 void fc_fcp_complete(struct fc_fcp_pkt *fsp)
1933 {
1934         if (fc_fcp_lock_pkt(fsp))
1935                 return;
1936
1937         fc_fcp_complete_locked(fsp);
1938         fc_fcp_unlock_pkt(fsp);
1939 }
1940 EXPORT_SYMBOL(fc_fcp_complete);
1941
1942 /**
1943  * fc_eh_abort() - Abort a command
1944  * @sc_cmd:     scsi command to abort
1945  *
1946  * From scsi host template.
1947  * send ABTS to the target device  and wait for the response
1948  * sc_cmd is the pointer to the command to be aborted.
1949  */
1950 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
1951 {
1952         struct fc_fcp_pkt *fsp;
1953         struct fc_lport *lp;
1954         int rc = FAILED;
1955         unsigned long flags;
1956
1957         lp = shost_priv(sc_cmd->device->host);
1958         if (lp->state != LPORT_ST_READY)
1959                 return rc;
1960         else if (!lp->link_up)
1961                 return rc;
1962
1963         spin_lock_irqsave(lp->host->host_lock, flags);
1964         fsp = CMD_SP(sc_cmd);
1965         if (!fsp) {
1966                 /* command completed while scsi eh was setting up */
1967                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1968                 return SUCCESS;
1969         }
1970         /* grab a ref so the fsp and sc_cmd cannot be relased from under us */
1971         fc_fcp_pkt_hold(fsp);
1972         spin_unlock_irqrestore(lp->host->host_lock, flags);
1973
1974         if (fc_fcp_lock_pkt(fsp)) {
1975                 /* completed while we were waiting for timer to be deleted */
1976                 rc = SUCCESS;
1977                 goto release_pkt;
1978         }
1979
1980         rc = fc_fcp_pkt_abort(lp, fsp);
1981         fc_fcp_unlock_pkt(fsp);
1982
1983 release_pkt:
1984         fc_fcp_pkt_release(fsp);
1985         return rc;
1986 }
1987 EXPORT_SYMBOL(fc_eh_abort);
1988
1989 /**
1990  * fc_eh_device_reset() Reset a single LUN
1991  * @sc_cmd:     scsi command
1992  *
1993  * Set from scsi host template to send tm cmd to the target and wait for the
1994  * response.
1995  */
1996 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
1997 {
1998         struct fc_lport *lp;
1999         struct fc_fcp_pkt *fsp;
2000         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2001         int rc = FAILED;
2002         struct fc_rport_libfc_priv *rp;
2003         int rval;
2004
2005         rval = fc_remote_port_chkready(rport);
2006         if (rval)
2007                 goto out;
2008
2009         rp = rport->dd_data;
2010         lp = shost_priv(sc_cmd->device->host);
2011
2012         if (lp->state != LPORT_ST_READY)
2013                 return rc;
2014
2015         fsp = fc_fcp_pkt_alloc(lp, GFP_NOIO);
2016         if (fsp == NULL) {
2017                 FC_DBG("could not allocate scsi_pkt\n");
2018                 sc_cmd->result = DID_NO_CONNECT << 16;
2019                 goto out;
2020         }
2021
2022         /*
2023          * Build the libfc request pkt. Do not set the scsi cmnd, because
2024          * the sc passed in is not setup for execution like when sent
2025          * through the queuecommand callout.
2026          */
2027         fsp->lp = lp;           /* save the softc ptr */
2028         fsp->rport = rport;     /* set the remote port ptr */
2029
2030         /*
2031          * flush outstanding commands
2032          */
2033         rc = fc_lun_reset(lp, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2034         fsp->state = FC_SRB_FREE;
2035         fc_fcp_pkt_release(fsp);
2036
2037 out:
2038         return rc;
2039 }
2040 EXPORT_SYMBOL(fc_eh_device_reset);
2041
2042 /**
2043  * fc_eh_host_reset() - The reset function will reset the ports on the host.
2044  * @sc_cmd:     scsi command
2045  */
2046 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2047 {
2048         struct Scsi_Host *shost = sc_cmd->device->host;
2049         struct fc_lport *lp = shost_priv(shost);
2050         unsigned long wait_tmo;
2051
2052         lp->tt.lport_reset(lp);
2053         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2054         while (!fc_fcp_lport_queue_ready(lp) && time_before(jiffies, wait_tmo))
2055                 msleep(1000);
2056
2057         if (fc_fcp_lport_queue_ready(lp)) {
2058                 shost_printk(KERN_INFO, shost, "Host reset succeeded.\n");
2059                 return SUCCESS;
2060         } else {
2061                 shost_printk(KERN_INFO, shost, "Host reset failed. "
2062                              "lport not ready.\n");
2063                 return FAILED;
2064         }
2065 }
2066 EXPORT_SYMBOL(fc_eh_host_reset);
2067
2068 /**
2069  * fc_slave_alloc() - configure queue depth
2070  * @sdev:       scsi device
2071  *
2072  * Configures queue depth based on host's cmd_per_len. If not set
2073  * then we use the libfc default.
2074  */
2075 int fc_slave_alloc(struct scsi_device *sdev)
2076 {
2077         struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2078         int queue_depth;
2079
2080         if (!rport || fc_remote_port_chkready(rport))
2081                 return -ENXIO;
2082
2083         if (sdev->tagged_supported) {
2084                 if (sdev->host->hostt->cmd_per_lun)
2085                         queue_depth = sdev->host->hostt->cmd_per_lun;
2086                 else
2087                         queue_depth = FC_FCP_DFLT_QUEUE_DEPTH;
2088                 scsi_activate_tcq(sdev, queue_depth);
2089         }
2090         return 0;
2091 }
2092 EXPORT_SYMBOL(fc_slave_alloc);
2093
2094 int fc_change_queue_depth(struct scsi_device *sdev, int qdepth)
2095 {
2096         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2097         return sdev->queue_depth;
2098 }
2099 EXPORT_SYMBOL(fc_change_queue_depth);
2100
2101 int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2102 {
2103         if (sdev->tagged_supported) {
2104                 scsi_set_tag_type(sdev, tag_type);
2105                 if (tag_type)
2106                         scsi_activate_tcq(sdev, sdev->queue_depth);
2107                 else
2108                         scsi_deactivate_tcq(sdev, sdev->queue_depth);
2109         } else
2110                 tag_type = 0;
2111
2112         return tag_type;
2113 }
2114 EXPORT_SYMBOL(fc_change_queue_type);
2115
2116 void fc_fcp_destroy(struct fc_lport *lp)
2117 {
2118         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
2119
2120         if (!list_empty(&si->scsi_pkt_queue))
2121                 printk(KERN_ERR "Leaked scsi packets.\n");
2122
2123         mempool_destroy(si->scsi_pkt_pool);
2124         kfree(si);
2125         lp->scsi_priv = NULL;
2126 }
2127 EXPORT_SYMBOL(fc_fcp_destroy);
2128
2129 int fc_fcp_init(struct fc_lport *lp)
2130 {
2131         int rc;
2132         struct fc_fcp_internal *si;
2133
2134         if (!lp->tt.fcp_cmd_send)
2135                 lp->tt.fcp_cmd_send = fc_fcp_cmd_send;
2136
2137         if (!lp->tt.fcp_cleanup)
2138                 lp->tt.fcp_cleanup = fc_fcp_cleanup;
2139
2140         if (!lp->tt.fcp_abort_io)
2141                 lp->tt.fcp_abort_io = fc_fcp_abort_io;
2142
2143         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2144         if (!si)
2145                 return -ENOMEM;
2146         lp->scsi_priv = si;
2147         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2148
2149         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2150         if (!si->scsi_pkt_pool) {
2151                 rc = -ENOMEM;
2152                 goto free_internal;
2153         }
2154         return 0;
2155
2156 free_internal:
2157         kfree(si);
2158         return rc;
2159 }
2160 EXPORT_SYMBOL(fc_fcp_init);
2161
2162 static int __init libfc_init(void)
2163 {
2164         int rc;
2165
2166         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2167                                             sizeof(struct fc_fcp_pkt),
2168                                             0, SLAB_HWCACHE_ALIGN, NULL);
2169         if (scsi_pkt_cachep == NULL) {
2170                 FC_DBG("Unable to allocate SRB cache...module load failed!");
2171                 return -ENOMEM;
2172         }
2173
2174         rc = fc_setup_exch_mgr();
2175         if (rc)
2176                 goto destroy_pkt_cache;
2177
2178         rc = fc_setup_rport();
2179         if (rc)
2180                 goto destroy_em;
2181
2182         return rc;
2183 destroy_em:
2184         fc_destroy_exch_mgr();
2185 destroy_pkt_cache:
2186         kmem_cache_destroy(scsi_pkt_cachep);
2187         return rc;
2188 }
2189
2190 static void __exit libfc_exit(void)
2191 {
2192         kmem_cache_destroy(scsi_pkt_cachep);
2193         fc_destroy_exch_mgr();
2194         fc_destroy_rport();
2195 }
2196
2197 module_init(libfc_init);
2198 module_exit(libfc_exit);