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 unsigned int fc_debug_logging;
  47 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
  48 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
  49
  50 static struct kmem_cache *scsi_pkt_cachep;
  51
  52 /* SRB state definitions */
  53 #define FC_SRB_FREE             0               /* cmd is free */
  54 #define FC_SRB_CMD_SENT         (1 << 0)        /* cmd has been sent */
  55 #define FC_SRB_RCV_STATUS       (1 << 1)        /* response has arrived */
  56 #define FC_SRB_ABORT_PENDING    (1 << 2)        /* cmd abort sent to device */
  57 #define FC_SRB_ABORTED          (1 << 3)        /* abort acknowleged */
  58 #define FC_SRB_DISCONTIG        (1 << 4)        /* non-sequential data recvd */
  59 #define FC_SRB_COMPL            (1 << 5)        /* fc_io_compl has been run */
  60 #define FC_SRB_FCP_PROCESSING_TMO (1 << 6)      /* timer function processing */
  61 #define FC_SRB_NOMEM            (1 << 7)        /* dropped to out of mem */
  62
  63 #define FC_SRB_READ             (1 << 1)
  64 #define FC_SRB_WRITE            (1 << 0)
  65
  66 /*
  67  * The SCp.ptr should be tested and set under the host lock. NULL indicates
  68  * that the command has been retruned to the scsi layer.
  69  */
  70 #define CMD_SP(Cmnd)                ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
  71 #define CMD_ENTRY_STATUS(Cmnd)      ((Cmnd)->SCp.have_data_in)
  72 #define CMD_COMPL_STATUS(Cmnd)      ((Cmnd)->SCp.this_residual)
  73 #define CMD_SCSI_STATUS(Cmnd)       ((Cmnd)->SCp.Status)
  74 #define CMD_RESID_LEN(Cmnd)         ((Cmnd)->SCp.buffers_residual)
  75
  76 struct fc_fcp_internal {
  77         mempool_t       *scsi_pkt_pool;
  78         struct list_head scsi_pkt_queue;
  79         u8              throttled;
  80 };
  81
  82 #define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
  83
  84 /*
  85  * function prototypes
  86  * FC scsi I/O related functions
  87  */
  88 static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  89 static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  90 static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  91 static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  92 static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  93 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp);
  94 static void fc_timeout_error(struct fc_fcp_pkt *);
  95 static void fc_fcp_timeout(unsigned long data);
  96 static void fc_fcp_rec(struct fc_fcp_pkt *);
  97 static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
  98 static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
  99 static void fc_io_compl(struct fc_fcp_pkt *);
 100
 101 static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
 102 static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
 103 static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
 104
 105 /*
 106  * command status codes
 107  */
 108 #define FC_COMPLETE             0
 109 #define FC_CMD_ABORTED          1
 110 #define FC_CMD_RESET            2
 111 #define FC_CMD_PLOGO            3
 112 #define FC_SNS_RCV              4
 113 #define FC_TRANS_ERR            5
 114 #define FC_DATA_OVRRUN          6
 115 #define FC_DATA_UNDRUN          7
 116 #define FC_ERROR                8
 117 #define FC_HRD_ERROR            9
 118 #define FC_CMD_TIME_OUT         10
 119
 120 /*
 121  * Error recovery timeout values.
 122  */
 123 #define FC_SCSI_ER_TIMEOUT      (10 * HZ)
 124 #define FC_SCSI_TM_TOV          (10 * HZ)
 125 #define FC_SCSI_REC_TOV         (2 * HZ)
 126 #define FC_HOST_RESET_TIMEOUT   (30 * HZ)
 127
 128 #define FC_MAX_ERROR_CNT        5
 129 #define FC_MAX_RECOV_RETRY      3
 130
 131 #define FC_FCP_DFLT_QUEUE_DEPTH 32
 132
 133 /**
 134  * fc_fcp_pkt_alloc - allocation routine for scsi_pkt packet
 135  * @lp:         fc lport struct
 136  * @gfp:        gfp flags for allocation
 137  *
 138  * This is used by upper layer scsi driver.
 139  * Return Value : scsi_pkt structure or null on allocation failure.
 140  * Context      : call from process context. no locking required.
 141  */
 142 static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lp, gfp_t gfp)
 143 {
 144         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 145         struct fc_fcp_pkt *fsp;
 146
 147         fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
 148         if (fsp) {
 149                 memset(fsp, 0, sizeof(*fsp));
 150                 fsp->lp = lp;
 151                 atomic_set(&fsp->ref_cnt, 1);
 152                 init_timer(&fsp->timer);
 153                 INIT_LIST_HEAD(&fsp->list);
 154                 spin_lock_init(&fsp->scsi_pkt_lock);
 155         }
 156         return fsp;
 157 }
 158
 159 /**
 160  * fc_fcp_pkt_release() - release hold on scsi_pkt packet
 161  * @fsp:        fcp packet struct
 162  *
 163  * This is used by upper layer scsi driver.
 164  * Context      : call from process  and interrupt context.
 165  *                no locking required
 166  */
 167 static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
 168 {
 169         if (atomic_dec_and_test(&fsp->ref_cnt)) {
 170                 struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 171
 172                 mempool_free(fsp, si->scsi_pkt_pool);
 173         }
 174 }
 175
 176 static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
 177 {
 178         atomic_inc(&fsp->ref_cnt);
 179 }
 180
 181 /**
 182  * fc_fcp_pkt_destory() - release hold on scsi_pkt packet
 183  * @seq:                exchange sequence
 184  * @fsp:        fcp packet struct
 185  *
 186  * Release hold on scsi_pkt packet set to keep scsi_pkt
 187  * till EM layer exch resource is not freed.
 188  * Context      : called from from EM layer.
 189  *                no locking required
 190  */
 191 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 192 {
 193         fc_fcp_pkt_release(fsp);
 194 }
 195
 196 /**
 197  * fc_fcp_lock_pkt() - lock a packet and get a ref to it.
 198  * @fsp:        fcp packet
 199  *
 200  * We should only return error if we return a command to scsi-ml before
 201  * getting a response. This can happen in cases where we send a abort, but
 202  * do not wait for the response and the abort and command can be passing
 203  * each other on the wire/network-layer.
 204  *
 205  * Note: this function locks the packet and gets a reference to allow
 206  * callers to call the completion function while the lock is held and
 207  * not have to worry about the packets refcount.
 208  *
 209  * TODO: Maybe we should just have callers grab/release the lock and
 210  * have a function that they call to verify the fsp and grab a ref if
 211  * needed.
 212  */
 213 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 214 {
 215         spin_lock_bh(&fsp->scsi_pkt_lock);
 216         if (fsp->state & FC_SRB_COMPL) {
 217                 spin_unlock_bh(&fsp->scsi_pkt_lock);
 218                 return -EPERM;
 219         }
 220
 221         fc_fcp_pkt_hold(fsp);
 222         return 0;
 223 }
 224
 225 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 226 {
 227         spin_unlock_bh(&fsp->scsi_pkt_lock);
 228         fc_fcp_pkt_release(fsp);
 229 }
 230
 231 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 232 {
 233         if (!(fsp->state & FC_SRB_COMPL))
 234                 mod_timer(&fsp->timer, jiffies + delay);
 235 }
 236
 237 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 238 {
 239         if (!fsp->seq_ptr)
 240                 return -EINVAL;
 241
 242         fsp->state |= FC_SRB_ABORT_PENDING;
 243         return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
 244 }
 245
 246 /*
 247  * Retry command.
 248  * An abort isn't needed.
 249  */
 250 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
 251 {
 252         if (fsp->seq_ptr) {
 253                 fsp->lp->tt.exch_done(fsp->seq_ptr);
 254                 fsp->seq_ptr = NULL;
 255         }
 256
 257         fsp->state &= ~FC_SRB_ABORT_PENDING;
 258         fsp->io_status = 0;
 259         fsp->status_code = FC_ERROR;
 260         fc_fcp_complete_locked(fsp);
 261 }
 262
 263 /*
 264  * fc_fcp_ddp_setup - calls to LLD's ddp_setup to set up DDP
 265  * transfer for a read I/O indicated by the fc_fcp_pkt.
 266  * @fsp: ptr to the fc_fcp_pkt
 267  *
 268  * This is called in exch_seq_send() when we have a newly allocated
 269  * exchange with a valid exchange id to setup ddp.
 270  *
 271  * returns: none
 272  */
 273 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
 274 {
 275         struct fc_lport *lp;
 276
 277         if (!fsp)
 278                 return;
 279
 280         lp = fsp->lp;
 281         if ((fsp->req_flags & FC_SRB_READ) &&
 282             (lp->lro_enabled) && (lp->tt.ddp_setup)) {
 283                 if (lp->tt.ddp_setup(lp, xid, scsi_sglist(fsp->cmd),
 284                                      scsi_sg_count(fsp->cmd)))
 285                         fsp->xfer_ddp = xid;
 286         }
 287 }
 288 EXPORT_SYMBOL(fc_fcp_ddp_setup);
 289
 290 /*
 291  * fc_fcp_ddp_done - calls to LLD's ddp_done to release any
 292  * DDP related resources for this I/O if it is initialized
 293  * as a ddp transfer
 294  * @fsp: ptr to the fc_fcp_pkt
 295  *
 296  * returns: none
 297  */
 298 static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
 299 {
 300         struct fc_lport *lp;
 301
 302         if (!fsp)
 303                 return;
 304
 305         lp = fsp->lp;
 306         if (fsp->xfer_ddp && lp->tt.ddp_done) {
 307                 fsp->xfer_len = lp->tt.ddp_done(lp, fsp->xfer_ddp);
 308                 fsp->xfer_ddp = 0;
 309         }
 310 }
 311
 312
 313 /*
 314  * Receive SCSI data from target.
 315  * Called after receiving solicited data.
 316  */
 317 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 318 {
 319         struct scsi_cmnd *sc = fsp->cmd;
 320         struct fc_lport *lp = fsp->lp;
 321         struct fcoe_dev_stats *stats;
 322         struct fc_frame_header *fh;
 323         size_t start_offset;
 324         size_t offset;
 325         u32 crc;
 326         u32 copy_len = 0;
 327         size_t len;
 328         void *buf;
 329         struct scatterlist *sg;
 330         size_t remaining;
 331
 332         fh = fc_frame_header_get(fp);
 333         offset = ntohl(fh->fh_parm_offset);
 334         start_offset = offset;
 335         len = fr_len(fp) - sizeof(*fh);
 336         buf = fc_frame_payload_get(fp, 0);
 337
 338         /* if this I/O is ddped, update xfer len */
 339         fc_fcp_ddp_done(fsp);
 340
 341         if (offset + len > fsp->data_len) {
 342                 /* this should never happen */
 343                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 344                     fc_frame_crc_check(fp))
 345                         goto crc_err;
 346                 FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
 347                            "data_len %x\n", len, offset, fsp->data_len);
 348                 fc_fcp_retry_cmd(fsp);
 349                 return;
 350         }
 351         if (offset != fsp->xfer_len)
 352                 fsp->state |= FC_SRB_DISCONTIG;
 353
 354         crc = 0;
 355         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 356                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 357
 358         sg = scsi_sglist(sc);
 359         remaining = len;
 360
 361         while (remaining > 0 && sg) {
 362                 size_t off;
 363                 void *page_addr;
 364                 size_t sg_bytes;
 365
 366                 if (offset >= sg->length) {
 367                         offset -= sg->length;
 368                         sg = sg_next(sg);
 369                         continue;
 370                 }
 371                 sg_bytes = min(remaining, sg->length - offset);
 372
 373                 /*
 374                  * The scatterlist item may be bigger than PAGE_SIZE,
 375                  * but we are limited to mapping PAGE_SIZE at a time.
 376                  */
 377                 off = offset + sg->offset;
 378                 sg_bytes = min(sg_bytes, (size_t)
 379                                (PAGE_SIZE - (off & ~PAGE_MASK)));
 380                 page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT),
 381                                         KM_SOFTIRQ0);
 382                 if (!page_addr)
 383                         break;          /* XXX panic? */
 384
 385                 if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
 386                         crc = crc32(crc, buf, sg_bytes);
 387                 memcpy((char *)page_addr + (off & ~PAGE_MASK), buf,
 388                        sg_bytes);
 389
 390                 kunmap_atomic(page_addr, KM_SOFTIRQ0);
 391                 buf += sg_bytes;
 392                 offset += sg_bytes;
 393                 remaining -= sg_bytes;
 394                 copy_len += sg_bytes;
 395         }
 396
 397         if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
 398                 buf = fc_frame_payload_get(fp, 0);
 399                 if (len % 4) {
 400                         crc = crc32(crc, buf + len, 4 - (len % 4));
 401                         len += 4 - (len % 4);
 402                 }
 403
 404                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 405 crc_err:
 406                         stats = fc_lport_get_stats(lp);
 407                         stats->ErrorFrames++;
 408                         /* FIXME - per cpu count, not total count! */
 409                         if (stats->InvalidCRCCount++ < 5)
 410                                 printk(KERN_WARNING "libfc: CRC error on data "
 411                                        "frame for port (%6x)\n",
 412                                        fc_host_port_id(lp->host));
 413                         /*
 414                          * Assume the frame is total garbage.
 415                          * We may have copied it over the good part
 416                          * of the buffer.
 417                          * If so, we need to retry the entire operation.
 418                          * Otherwise, ignore it.
 419                          */
 420                         if (fsp->state & FC_SRB_DISCONTIG)
 421                                 fc_fcp_retry_cmd(fsp);
 422                         return;
 423                 }
 424         }
 425
 426         if (fsp->xfer_contig_end == start_offset)
 427                 fsp->xfer_contig_end += copy_len;
 428         fsp->xfer_len += copy_len;
 429
 430         /*
 431          * In the very rare event that this data arrived after the response
 432          * and completes the transfer, call the completion handler.
 433          */
 434         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 435             fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
 436                 fc_fcp_complete_locked(fsp);
 437 }
 438
 439 /**
 440  * fc_fcp_send_data() -  Send SCSI data to target.
 441  * @fsp: ptr to fc_fcp_pkt
 442  * @sp: ptr to this sequence
 443  * @offset: starting offset for this data request
 444  * @seq_blen: the burst length for this data request
 445  *
 446  * Called after receiving a Transfer Ready data descriptor.
 447  * if LLD is capable of seq offload then send down seq_blen
 448  * size of data in single frame, otherwise send multiple FC
 449  * frames of max FC frame payload supported by target port.
 450  *
 451  * Returns : 0 for success.
 452  */
 453 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 454                             size_t offset, size_t seq_blen)
 455 {
 456         struct fc_exch *ep;
 457         struct scsi_cmnd *sc;
 458         struct scatterlist *sg;
 459         struct fc_frame *fp = NULL;
 460         struct fc_lport *lp = fsp->lp;
 461         size_t remaining;
 462         size_t t_blen;
 463         size_t tlen;
 464         size_t sg_bytes;
 465         size_t frame_offset, fh_parm_offset;
 466         int error;
 467         void *data = NULL;
 468         void *page_addr;
 469         int using_sg = lp->sg_supp;
 470         u32 f_ctl;
 471
 472         WARN_ON(seq_blen <= 0);
 473         if (unlikely(offset + seq_blen > fsp->data_len)) {
 474                 /* this should never happen */
 475                 FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
 476                            "offset %zx\n", seq_blen, offset);
 477                 fc_fcp_send_abort(fsp);
 478                 return 0;
 479         } else if (offset != fsp->xfer_len) {
 480                 /* Out of Order Data Request - no problem, but unexpected. */
 481                 FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
 482                            "seq_blen %zx offset %zx\n", seq_blen, offset);
 483         }
 484
 485         /*
 486          * if LLD is capable of seq_offload then set transport
 487          * burst length (t_blen) to seq_blen, otherwise set t_blen
 488          * to max FC frame payload previously set in fsp->max_payload.
 489          */
 490         t_blen = fsp->max_payload;
 491         if (lp->seq_offload) {
 492                 t_blen = min(seq_blen, (size_t)lp->lso_max);
 493                 FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
 494                            fsp, seq_blen, lp->lso_max, t_blen);
 495         }
 496
 497         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
 498         if (t_blen > 512)
 499                 t_blen &= ~(512 - 1);   /* round down to block size */
 500         WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);   /* won't go below 256 */
 501         sc = fsp->cmd;
 502
 503         remaining = seq_blen;
 504         fh_parm_offset = frame_offset = offset;
 505         tlen = 0;
 506         seq = lp->tt.seq_start_next(seq);
 507         f_ctl = FC_FC_REL_OFF;
 508         WARN_ON(!seq);
 509
 510         /*
 511          * If a get_page()/put_page() will fail, don't use sg lists
 512          * in the fc_frame structure.
 513          *
 514          * The put_page() may be long after the I/O has completed
 515          * in the case of FCoE, since the network driver does it
 516          * via free_skb().  See the test in free_pages_check().
 517          *
 518          * Test this case with 'dd </dev/zero >/dev/st0 bs=64k'.
 519          */
 520         if (using_sg) {
 521                 for (sg = scsi_sglist(sc); sg; sg = sg_next(sg)) {
 522                         if (page_count(sg_page(sg)) == 0 ||
 523                             (sg_page(sg)->flags & (1 << PG_lru |
 524                                                    1 << PG_private |
 525                                                    1 << PG_locked |
 526                                                    1 << PG_active |
 527                                                    1 << PG_slab |
 528                                                    1 << PG_swapcache |
 529                                                    1 << PG_writeback |
 530                                                    1 << PG_reserved |
 531                                                    1 << PG_buddy))) {
 532                                 using_sg = 0;
 533                                 break;
 534                         }
 535                 }
 536         }
 537         sg = scsi_sglist(sc);
 538
 539         while (remaining > 0 && sg) {
 540                 if (offset >= sg->length) {
 541                         offset -= sg->length;
 542                         sg = sg_next(sg);
 543                         continue;
 544                 }
 545                 if (!fp) {
 546                         tlen = min(t_blen, remaining);
 547
 548                         /*
 549                          * TODO.  Temporary workaround.  fc_seq_send() can't
 550                          * handle odd lengths in non-linear skbs.
 551                          * This will be the final fragment only.
 552                          */
 553                         if (tlen % 4)
 554                                 using_sg = 0;
 555                         if (using_sg) {
 556                                 fp = _fc_frame_alloc(lp, 0);
 557                                 if (!fp)
 558                                         return -ENOMEM;
 559                         } else {
 560                                 fp = fc_frame_alloc(lp, tlen);
 561                                 if (!fp)
 562                                         return -ENOMEM;
 563
 564                                 data = (void *)(fr_hdr(fp)) +
 565                                         sizeof(struct fc_frame_header);
 566                         }
 567                         fh_parm_offset = frame_offset;
 568                         fr_max_payload(fp) = fsp->max_payload;
 569                 }
 570                 sg_bytes = min(tlen, sg->length - offset);
 571                 if (using_sg) {
 572                         WARN_ON(skb_shinfo(fp_skb(fp))->nr_frags >
 573                                 FC_FRAME_SG_LEN);
 574                         get_page(sg_page(sg));
 575                         skb_fill_page_desc(fp_skb(fp),
 576                                            skb_shinfo(fp_skb(fp))->nr_frags,
 577                                            sg_page(sg), sg->offset + offset,
 578                                            sg_bytes);
 579                         fp_skb(fp)->data_len += sg_bytes;
 580                         fr_len(fp) += sg_bytes;
 581                         fp_skb(fp)->truesize += PAGE_SIZE;
 582                 } else {
 583                         size_t off = offset + sg->offset;
 584
 585                         /*
 586                          * The scatterlist item may be bigger than PAGE_SIZE,
 587                          * but we must not cross pages inside the kmap.
 588                          */
 589                         sg_bytes = min(sg_bytes, (size_t) (PAGE_SIZE -
 590                                                            (off & ~PAGE_MASK)));
 591                         page_addr = kmap_atomic(sg_page(sg) +
 592                                                 (off >> PAGE_SHIFT),
 593                                                 KM_SOFTIRQ0);
 594                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 595                                sg_bytes);
 596                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
 597                         data += sg_bytes;
 598                 }
 599                 offset += sg_bytes;
 600                 frame_offset += sg_bytes;
 601                 tlen -= sg_bytes;
 602                 remaining -= sg_bytes;
 603
 604                 if (tlen)
 605                         continue;
 606
 607                 /*
 608                  * Send sequence with transfer sequence initiative in case
 609                  * this is last FCP frame of the sequence.
 610                  */
 611                 if (remaining == 0)
 612                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 613
 614                 ep = fc_seq_exch(seq);
 615                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 616                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
 617
 618                 /*
 619                  * send fragment using for a sequence.
 620                  */
 621                 error = lp->tt.seq_send(lp, seq, fp);
 622                 if (error) {
 623                         WARN_ON(1);             /* send error should be rare */
 624                         fc_fcp_retry_cmd(fsp);
 625                         return 0;
 626                 }
 627                 fp = NULL;
 628         }
 629         fsp->xfer_len += seq_blen;      /* premature count? */
 630         return 0;
 631 }
 632
 633 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 634 {
 635         int ba_done = 1;
 636         struct fc_ba_rjt *brp;
 637         struct fc_frame_header *fh;
 638
 639         fh = fc_frame_header_get(fp);
 640         switch (fh->fh_r_ctl) {
 641         case FC_RCTL_BA_ACC:
 642                 break;
 643         case FC_RCTL_BA_RJT:
 644                 brp = fc_frame_payload_get(fp, sizeof(*brp));
 645                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 646                         break;
 647                 /* fall thru */
 648         default:
 649                 /*
 650                  * we will let the command timeout
 651                  * and scsi-ml recover in this case,
 652                  * therefore cleared the ba_done flag.
 653                  */
 654                 ba_done = 0;
 655         }
 656
 657         if (ba_done) {
 658                 fsp->state |= FC_SRB_ABORTED;
 659                 fsp->state &= ~FC_SRB_ABORT_PENDING;
 660
 661                 if (fsp->wait_for_comp)
 662                         complete(&fsp->tm_done);
 663                 else
 664                         fc_fcp_complete_locked(fsp);
 665         }
 666 }
 667
 668 /**
 669  * fc_fcp_reduce_can_queue() - drop can_queue
 670  * @lp: lport to drop queueing for
 671  *
 672  * If we are getting memory allocation failures, then we may
 673  * be trying to execute too many commands. We let the running
 674  * commands complete or timeout, then try again with a reduced
 675  * can_queue. Eventually we will hit the point where we run
 676  * on all reserved structs.
 677  */
 678 static void fc_fcp_reduce_can_queue(struct fc_lport *lp)
 679 {
 680         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 681         unsigned long flags;
 682         int can_queue;
 683
 684         spin_lock_irqsave(lp->host->host_lock, flags);
 685         if (si->throttled)
 686                 goto done;
 687         si->throttled = 1;
 688
 689         can_queue = lp->host->can_queue;
 690         can_queue >>= 1;
 691         if (!can_queue)
 692                 can_queue = 1;
 693         lp->host->can_queue = can_queue;
 694         shost_printk(KERN_ERR, lp->host, "libfc: Could not allocate frame.\n"
 695                      "Reducing can_queue to %d.\n", can_queue);
 696 done:
 697         spin_unlock_irqrestore(lp->host->host_lock, flags);
 698 }
 699
 700 /**
 701  * fc_fcp_recv() - Reveive FCP frames
 702  * @seq: The sequence the frame is on
 703  * @fp: The FC frame
 704  * @arg: The related FCP packet
 705  *
 706  * Return   : None
 707  * Context  : called from Soft IRQ context
 708  *            can not called holding list lock
 709  */
 710 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 711 {
 712         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 713         struct fc_lport *lport = fsp->lp;
 714         struct fc_frame_header *fh;
 715         struct fcp_txrdy *dd;
 716         u8 r_ctl;
 717         int rc = 0;
 718
 719         if (IS_ERR(fp))
 720                 goto errout;
 721
 722         fh = fc_frame_header_get(fp);
 723         r_ctl = fh->fh_r_ctl;
 724
 725         if (!(lport->state & LPORT_ST_READY))
 726                 goto out;
 727         if (fc_fcp_lock_pkt(fsp))
 728                 goto out;
 729         fsp->last_pkt_time = jiffies;
 730
 731         if (fh->fh_type == FC_TYPE_BLS) {
 732                 fc_fcp_abts_resp(fsp, fp);
 733                 goto unlock;
 734         }
 735
 736         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
 737                 goto unlock;
 738
 739         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 740                 /*
 741                  * received XFER RDY from the target
 742                  * need to send data to the target
 743                  */
 744                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 745                 dd = fc_frame_payload_get(fp, sizeof(*dd));
 746                 WARN_ON(!dd);
 747
 748                 rc = fc_fcp_send_data(fsp, seq,
 749                                       (size_t) ntohl(dd->ft_data_ro),
 750                                       (size_t) ntohl(dd->ft_burst_len));
 751                 if (!rc)
 752                         seq->rec_data = fsp->xfer_len;
 753                 else if (rc == -ENOMEM)
 754                         fsp->state |= FC_SRB_NOMEM;
 755         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 756                 /*
 757                  * received a DATA frame
 758                  * next we will copy the data to the system buffer
 759                  */
 760                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
 761                 fc_fcp_recv_data(fsp, fp);
 762                 seq->rec_data = fsp->xfer_contig_end;
 763         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 764                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 765
 766                 fc_fcp_resp(fsp, fp);
 767         } else {
 768                 FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
 769         }
 770 unlock:
 771         fc_fcp_unlock_pkt(fsp);
 772 out:
 773         fc_frame_free(fp);
 774 errout:
 775         if (IS_ERR(fp))
 776                 fc_fcp_error(fsp, fp);
 777         else if (rc == -ENOMEM)
 778                 fc_fcp_reduce_can_queue(lport);
 779 }
 780
 781 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 782 {
 783         struct fc_frame_header *fh;
 784         struct fcp_resp *fc_rp;
 785         struct fcp_resp_ext *rp_ex;
 786         struct fcp_resp_rsp_info *fc_rp_info;
 787         u32 plen;
 788         u32 expected_len;
 789         u32 respl = 0;
 790         u32 snsl = 0;
 791         u8 flags = 0;
 792
 793         plen = fr_len(fp);
 794         fh = (struct fc_frame_header *)fr_hdr(fp);
 795         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 796                 goto len_err;
 797         plen -= sizeof(*fh);
 798         fc_rp = (struct fcp_resp *)(fh + 1);
 799         fsp->cdb_status = fc_rp->fr_status;
 800         flags = fc_rp->fr_flags;
 801         fsp->scsi_comp_flags = flags;
 802         expected_len = fsp->data_len;
 803
 804         /* if ddp, update xfer len */
 805         fc_fcp_ddp_done(fsp);
 806
 807         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 808                 rp_ex = (void *)(fc_rp + 1);
 809                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 810                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 811                                 goto len_err;
 812                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 813                         if (flags & FCP_RSP_LEN_VAL) {
 814                                 respl = ntohl(rp_ex->fr_rsp_len);
 815                                 if (respl != sizeof(*fc_rp_info))
 816                                         goto len_err;
 817                                 if (fsp->wait_for_comp) {
 818                                         /* Abuse cdb_status for rsp code */
 819                                         fsp->cdb_status = fc_rp_info->rsp_code;
 820                                         complete(&fsp->tm_done);
 821                                         /*
 822                                          * tmfs will not have any scsi cmd so
 823                                          * exit here
 824                                          */
 825                                         return;
 826                                 } else
 827                                         goto err;
 828                         }
 829                         if (flags & FCP_SNS_LEN_VAL) {
 830                                 snsl = ntohl(rp_ex->fr_sns_len);
 831                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
 832                                         snsl = SCSI_SENSE_BUFFERSIZE;
 833                                 memcpy(fsp->cmd->sense_buffer,
 834                                        (char *)fc_rp_info + respl, snsl);
 835                         }
 836                 }
 837                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 838                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 839                                 goto len_err;
 840                         if (flags & FCP_RESID_UNDER) {
 841                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 842                                 /*
 843                                  * The cmnd->underflow is the minimum number of
 844                                  * bytes that must be transfered for this
 845                                  * command.  Provided a sense condition is not
 846                                  * present, make sure the actual amount
 847                                  * transferred is at least the underflow value
 848                                  * or fail.
 849                                  */
 850                                 if (!(flags & FCP_SNS_LEN_VAL) &&
 851                                     (fc_rp->fr_status == 0) &&
 852                                     (scsi_bufflen(fsp->cmd) -
 853                                      fsp->scsi_resid) < fsp->cmd->underflow)
 854                                         goto err;
 855                                 expected_len -= fsp->scsi_resid;
 856                         } else {
 857                                 fsp->status_code = FC_ERROR;
 858                         }
 859                 }
 860         }
 861         fsp->state |= FC_SRB_RCV_STATUS;
 862
 863         /*
 864          * Check for missing or extra data frames.
 865          */
 866         if (unlikely(fsp->xfer_len != expected_len)) {
 867                 if (fsp->xfer_len < expected_len) {
 868                         /*
 869                          * Some data may be queued locally,
 870                          * Wait a at least one jiffy to see if it is delivered.
 871                          * If this expires without data, we may do SRR.
 872                          */
 873                         fc_fcp_timer_set(fsp, 2);
 874                         return;
 875                 }
 876                 fsp->status_code = FC_DATA_OVRRUN;
 877                 FC_FCP_DBG(fsp, "tgt %6x xfer len %zx greater than expected, "
 878                            "len %x, data len %x\n",
 879                            fsp->rport->port_id,
 880                            fsp->xfer_len, expected_len, fsp->data_len);
 881         }
 882         fc_fcp_complete_locked(fsp);
 883         return;
 884
 885 len_err:
 886         FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
 887                    "snsl %u\n", flags, fr_len(fp), respl, snsl);
 888 err:
 889         fsp->status_code = FC_ERROR;
 890         fc_fcp_complete_locked(fsp);
 891 }
 892
 893 /**
 894  * fc_fcp_complete_locked() - complete processing of a fcp packet
 895  * @fsp:        fcp packet
 896  *
 897  * This function may sleep if a timer is pending. The packet lock must be
 898  * held, and the host lock must not be held.
 899  */
 900 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 901 {
 902         struct fc_lport *lp = fsp->lp;
 903         struct fc_seq *seq;
 904         struct fc_exch *ep;
 905         u32 f_ctl;
 906
 907         if (fsp->state & FC_SRB_ABORT_PENDING)
 908                 return;
 909
 910         if (fsp->state & FC_SRB_ABORTED) {
 911                 if (!fsp->status_code)
 912                         fsp->status_code = FC_CMD_ABORTED;
 913         } else {
 914                 /*
 915                  * Test for transport underrun, independent of response
 916                  * underrun status.
 917                  */
 918                 if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
 919                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
 920                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
 921                         fsp->status_code = FC_DATA_UNDRUN;
 922                         fsp->io_status = 0;
 923                 }
 924         }
 925
 926         seq = fsp->seq_ptr;
 927         if (seq) {
 928                 fsp->seq_ptr = NULL;
 929                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
 930                         struct fc_frame *conf_frame;
 931                         struct fc_seq *csp;
 932
 933                         csp = lp->tt.seq_start_next(seq);
 934                         conf_frame = fc_frame_alloc(fsp->lp, 0);
 935                         if (conf_frame) {
 936                                 f_ctl = FC_FC_SEQ_INIT;
 937                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
 938                                 ep = fc_seq_exch(seq);
 939                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
 940                                                ep->did, ep->sid,
 941                                                FC_TYPE_FCP, f_ctl, 0);
 942                                 lp->tt.seq_send(lp, csp, conf_frame);
 943                         }
 944                 }
 945                 lp->tt.exch_done(seq);
 946         }
 947         fc_io_compl(fsp);
 948 }
 949
 950 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
 951 {
 952         struct fc_lport *lp = fsp->lp;
 953
 954         if (fsp->seq_ptr) {
 955                 lp->tt.exch_done(fsp->seq_ptr);
 956                 fsp->seq_ptr = NULL;
 957         }
 958         fsp->status_code = error;
 959 }
 960
 961 /**
 962  * fc_fcp_cleanup_each_cmd() - Cleanup active commads
 963  * @lp:         logical port
 964  * @id:         target id
 965  * @lun:        lun
 966  * @error:      fsp status code
 967  *
 968  * If lun or id is -1, they are ignored.
 969  */
 970 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lp, unsigned int id,
 971                                     unsigned int lun, int error)
 972 {
 973         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
 974         struct fc_fcp_pkt *fsp;
 975         struct scsi_cmnd *sc_cmd;
 976         unsigned long flags;
 977
 978         spin_lock_irqsave(lp->host->host_lock, flags);
 979 restart:
 980         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
 981                 sc_cmd = fsp->cmd;
 982                 if (id != -1 && scmd_id(sc_cmd) != id)
 983                         continue;
 984
 985                 if (lun != -1 && sc_cmd->device->lun != lun)
 986                         continue;
 987
 988                 fc_fcp_pkt_hold(fsp);
 989                 spin_unlock_irqrestore(lp->host->host_lock, flags);
 990
 991                 if (!fc_fcp_lock_pkt(fsp)) {
 992                         fc_fcp_cleanup_cmd(fsp, error);
 993                         fc_io_compl(fsp);
 994                         fc_fcp_unlock_pkt(fsp);
 995                 }
 996
 997                 fc_fcp_pkt_release(fsp);
 998                 spin_lock_irqsave(lp->host->host_lock, flags);
 999                 /*
1000                  * while we dropped the lock multiple pkts could
1001                  * have been released, so we have to start over.
1002                  */
1003                 goto restart;
1004         }
1005         spin_unlock_irqrestore(lp->host->host_lock, flags);
1006 }
1007
1008 static void fc_fcp_abort_io(struct fc_lport *lp)
1009 {
1010         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_HRD_ERROR);
1011 }
1012
1013 /**
1014  * fc_fcp_pkt_send() - send a fcp packet to the lower level.
1015  * @lp:         fc lport
1016  * @fsp:        fc packet.
1017  *
1018  * This is called by upper layer protocol.
1019  * Return   : zero for success and -1 for failure
1020  * Context  : called from queuecommand which can be called from process
1021  *            or scsi soft irq.
1022  * Locks    : called with the host lock and irqs disabled.
1023  */
1024 static int fc_fcp_pkt_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1025 {
1026         struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
1027         int rc;
1028
1029         fsp->cmd->SCp.ptr = (char *)fsp;
1030         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1031         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1032
1033         int_to_scsilun(fsp->cmd->device->lun,
1034                        (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1035         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1036         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1037
1038         spin_unlock_irq(lp->host->host_lock);
1039         rc = lp->tt.fcp_cmd_send(lp, fsp, fc_fcp_recv);
1040         spin_lock_irq(lp->host->host_lock);
1041         if (rc)
1042                 list_del(&fsp->list);
1043
1044         return rc;
1045 }
1046
1047 static int fc_fcp_cmd_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1048                            void (*resp)(struct fc_seq *,
1049                                         struct fc_frame *fp,
1050                                         void *arg))
1051 {
1052         struct fc_frame *fp;
1053         struct fc_seq *seq;
1054         struct fc_rport *rport;
1055         struct fc_rport_libfc_priv *rp;
1056         const size_t len = sizeof(fsp->cdb_cmd);
1057         int rc = 0;
1058
1059         if (fc_fcp_lock_pkt(fsp))
1060                 return 0;
1061
1062         fp = fc_frame_alloc(lp, sizeof(fsp->cdb_cmd));
1063         if (!fp) {
1064                 rc = -1;
1065                 goto unlock;
1066         }
1067
1068         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1069         fr_fsp(fp) = fsp;
1070         rport = fsp->rport;
1071         fsp->max_payload = rport->maxframe_size;
1072         rp = rport->dd_data;
1073
1074         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1075                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1076                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1077
1078         seq = lp->tt.exch_seq_send(lp, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1079         if (!seq) {
1080                 fc_frame_free(fp);
1081                 rc = -1;
1082                 goto unlock;
1083         }
1084         fsp->last_pkt_time = jiffies;
1085         fsp->seq_ptr = seq;
1086         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1087
1088         setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1089         fc_fcp_timer_set(fsp,
1090                          (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
1091                          FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
1092 unlock:
1093         fc_fcp_unlock_pkt(fsp);
1094         return rc;
1095 }
1096
1097 /*
1098  * transport error handler
1099  */
1100 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1101 {
1102         int error = PTR_ERR(fp);
1103
1104         if (fc_fcp_lock_pkt(fsp))
1105                 return;
1106
1107         if (error == -FC_EX_CLOSED) {
1108                 fc_fcp_retry_cmd(fsp);
1109                 goto unlock;
1110         }
1111
1112         /*
1113          * clear abort pending, because the lower layer
1114          * decided to force completion.
1115          */
1116         fsp->state &= ~FC_SRB_ABORT_PENDING;
1117         fsp->status_code = FC_CMD_PLOGO;
1118         fc_fcp_complete_locked(fsp);
1119 unlock:
1120         fc_fcp_unlock_pkt(fsp);
1121 }
1122
1123 /*
1124  * Scsi abort handler- calls to send an abort
1125  * and then wait for abort completion
1126  */
1127 static int fc_fcp_pkt_abort(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1128 {
1129         int rc = FAILED;
1130
1131         if (fc_fcp_send_abort(fsp))
1132                 return FAILED;
1133
1134         init_completion(&fsp->tm_done);
1135         fsp->wait_for_comp = 1;
1136
1137         spin_unlock_bh(&fsp->scsi_pkt_lock);
1138         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1139         spin_lock_bh(&fsp->scsi_pkt_lock);
1140         fsp->wait_for_comp = 0;
1141
1142         if (!rc) {
1143                 FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1144                 rc = FAILED;
1145         } else if (fsp->state & FC_SRB_ABORTED) {
1146                 FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1147                 rc = SUCCESS;
1148                 fc_fcp_complete_locked(fsp);
1149         }
1150
1151         return rc;
1152 }
1153
1154 /*
1155  * Retry LUN reset after resource allocation failed.
1156  */
1157 static void fc_lun_reset_send(unsigned long data)
1158 {
1159         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1160         struct fc_lport *lp = fsp->lp;
1161         if (lp->tt.fcp_cmd_send(lp, fsp, fc_tm_done)) {
1162                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1163                         return;
1164                 if (fc_fcp_lock_pkt(fsp))
1165                         return;
1166                 setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1167                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1168                 fc_fcp_unlock_pkt(fsp);
1169         }
1170 }
1171
1172 /*
1173  * Scsi device reset handler- send a LUN RESET to the device
1174  * and wait for reset reply
1175  */
1176 static int fc_lun_reset(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1177                         unsigned int id, unsigned int lun)
1178 {
1179         int rc;
1180
1181         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1182         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1183         int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1184
1185         fsp->wait_for_comp = 1;
1186         init_completion(&fsp->tm_done);
1187
1188         fc_lun_reset_send((unsigned long)fsp);
1189
1190         /*
1191          * wait for completion of reset
1192          * after that make sure all commands are terminated
1193          */
1194         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1195
1196         spin_lock_bh(&fsp->scsi_pkt_lock);
1197         fsp->state |= FC_SRB_COMPL;
1198         spin_unlock_bh(&fsp->scsi_pkt_lock);
1199
1200         del_timer_sync(&fsp->timer);
1201
1202         spin_lock_bh(&fsp->scsi_pkt_lock);
1203         if (fsp->seq_ptr) {
1204                 lp->tt.exch_done(fsp->seq_ptr);
1205                 fsp->seq_ptr = NULL;
1206         }
1207         fsp->wait_for_comp = 0;
1208         spin_unlock_bh(&fsp->scsi_pkt_lock);
1209
1210         if (!rc) {
1211                 FC_SCSI_DBG(lp, "lun reset failed\n");
1212                 return FAILED;
1213         }
1214
1215         /* cdb_status holds the tmf's rsp code */
1216         if (fsp->cdb_status != FCP_TMF_CMPL)
1217                 return FAILED;
1218
1219         FC_SCSI_DBG(lp, "lun reset to lun %u completed\n", lun);
1220         fc_fcp_cleanup_each_cmd(lp, id, lun, FC_CMD_ABORTED);
1221         return SUCCESS;
1222 }
1223
1224 /*
1225  * Task Managment response handler
1226  */
1227 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1228 {
1229         struct fc_fcp_pkt *fsp = arg;
1230         struct fc_frame_header *fh;
1231
1232         if (IS_ERR(fp)) {
1233                 /*
1234                  * If there is an error just let it timeout or wait
1235                  * for TMF to be aborted if it timedout.
1236                  *
1237                  * scsi-eh will escalate for when either happens.
1238                  */
1239                 return;
1240         }
1241
1242         if (fc_fcp_lock_pkt(fsp))
1243                 return;
1244
1245         /*
1246          * raced with eh timeout handler.
1247          */
1248         if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1249                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1250                 return;
1251         }
1252
1253         fh = fc_frame_header_get(fp);
1254         if (fh->fh_type != FC_TYPE_BLS)
1255                 fc_fcp_resp(fsp, fp);
1256         fsp->seq_ptr = NULL;
1257         fsp->lp->tt.exch_done(seq);
1258         fc_frame_free(fp);
1259         fc_fcp_unlock_pkt(fsp);
1260 }
1261
1262 static void fc_fcp_cleanup(struct fc_lport *lp)
1263 {
1264         fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_ERROR);
1265 }
1266
1267 /*
1268  * fc_fcp_timeout: called by OS timer function.
1269  *
1270  * The timer has been inactivated and must be reactivated if desired
1271  * using fc_fcp_timer_set().
1272  *
1273  * Algorithm:
1274  *
1275  * If REC is supported, just issue it, and return.  The REC exchange will
1276  * complete or time out, and recovery can continue at that point.
1277  *
1278  * Otherwise, if the response has been received without all the data,
1279  * it has been ER_TIMEOUT since the response was received.
1280  *
1281  * If the response has not been received,
1282  * we see if data was received recently.  If it has been, we continue waiting,
1283  * otherwise, we abort the command.
1284  */
1285 static void fc_fcp_timeout(unsigned long data)
1286 {
1287         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1288         struct fc_rport *rport = fsp->rport;
1289         struct fc_rport_libfc_priv *rp = rport->dd_data;
1290
1291         if (fc_fcp_lock_pkt(fsp))
1292                 return;
1293
1294         if (fsp->cdb_cmd.fc_tm_flags)
1295                 goto unlock;
1296
1297         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1298
1299         if (rp->flags & FC_RP_FLAGS_REC_SUPPORTED)
1300                 fc_fcp_rec(fsp);
1301         else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
1302                                jiffies))
1303                 fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1304         else if (fsp->state & FC_SRB_RCV_STATUS)
1305                 fc_fcp_complete_locked(fsp);
1306         else
1307                 fc_timeout_error(fsp);
1308         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1309 unlock:
1310         fc_fcp_unlock_pkt(fsp);
1311 }
1312
1313 /*
1314  * Send a REC ELS request
1315  */
1316 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1317 {
1318         struct fc_lport *lp;
1319         struct fc_frame *fp;
1320         struct fc_rport *rport;
1321         struct fc_rport_libfc_priv *rp;
1322
1323         lp = fsp->lp;
1324         rport = fsp->rport;
1325         rp = rport->dd_data;
1326         if (!fsp->seq_ptr || rp->rp_state != RPORT_ST_READY) {
1327                 fsp->status_code = FC_HRD_ERROR;
1328                 fsp->io_status = 0;
1329                 fc_fcp_complete_locked(fsp);
1330                 return;
1331         }
1332         fp = fc_frame_alloc(lp, sizeof(struct fc_els_rec));
1333         if (!fp)
1334                 goto retry;
1335
1336         fr_seq(fp) = fsp->seq_ptr;
1337         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1338                        fc_host_port_id(rp->local_port->host), FC_TYPE_ELS,
1339                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1340         if (lp->tt.elsct_send(lp, rport, fp, ELS_REC, fc_fcp_rec_resp,
1341                               fsp, jiffies_to_msecs(FC_SCSI_REC_TOV))) {
1342                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1343                 return;
1344         }
1345         fc_frame_free(fp);
1346 retry:
1347         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1348                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1349         else
1350                 fc_timeout_error(fsp);
1351 }
1352
1353 /*
1354  * Receive handler for REC ELS frame
1355  * if it is a reject then let the scsi layer to handle
1356  * the timeout. if it is a LS_ACC then if the io was not completed
1357  * then set the timeout and return otherwise complete the exchange
1358  * and tell the scsi layer to restart the I/O.
1359  */
1360 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1361 {
1362         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1363         struct fc_els_rec_acc *recp;
1364         struct fc_els_ls_rjt *rjt;
1365         u32 e_stat;
1366         u8 opcode;
1367         u32 offset;
1368         enum dma_data_direction data_dir;
1369         enum fc_rctl r_ctl;
1370         struct fc_rport_libfc_priv *rp;
1371
1372         if (IS_ERR(fp)) {
1373                 fc_fcp_rec_error(fsp, fp);
1374                 return;
1375         }
1376
1377         if (fc_fcp_lock_pkt(fsp))
1378                 goto out;
1379
1380         fsp->recov_retry = 0;
1381         opcode = fc_frame_payload_op(fp);
1382         if (opcode == ELS_LS_RJT) {
1383                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1384                 switch (rjt->er_reason) {
1385                 default:
1386                         FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1387                                    "reason %d expl %d\n",
1388                                    fsp->rport->port_id, rjt->er_reason,
1389                                    rjt->er_explan);
1390                         /* fall through */
1391                 case ELS_RJT_UNSUP:
1392                         FC_FCP_DBG(fsp, "device does not support REC\n");
1393                         rp = fsp->rport->dd_data;
1394                         /*
1395                          * if we do not spport RECs or got some bogus
1396                          * reason then resetup timer so we check for
1397                          * making progress.
1398                          */
1399                         rp->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1400                         fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1401                         break;
1402                 case ELS_RJT_LOGIC:
1403                 case ELS_RJT_UNAB:
1404                         /*
1405                          * If no data transfer, the command frame got dropped
1406                          * so we just retry.  If data was transferred, we
1407                          * lost the response but the target has no record,
1408                          * so we abort and retry.
1409                          */
1410                         if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1411                             fsp->xfer_len == 0) {
1412                                 fc_fcp_retry_cmd(fsp);
1413                                 break;
1414                         }
1415                         fc_timeout_error(fsp);
1416                         break;
1417                 }
1418         } else if (opcode == ELS_LS_ACC) {
1419                 if (fsp->state & FC_SRB_ABORTED)
1420                         goto unlock_out;
1421
1422                 data_dir = fsp->cmd->sc_data_direction;
1423                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1424                 offset = ntohl(recp->reca_fc4value);
1425                 e_stat = ntohl(recp->reca_e_stat);
1426
1427                 if (e_stat & ESB_ST_COMPLETE) {
1428
1429                         /*
1430                          * The exchange is complete.
1431                          *
1432                          * For output, we must've lost the response.
1433                          * For input, all data must've been sent.
1434                          * We lost may have lost the response
1435                          * (and a confirmation was requested) and maybe
1436                          * some data.
1437                          *
1438                          * If all data received, send SRR
1439                          * asking for response.  If partial data received,
1440                          * or gaps, SRR requests data at start of gap.
1441                          * Recovery via SRR relies on in-order-delivery.
1442                          */
1443                         if (data_dir == DMA_TO_DEVICE) {
1444                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1445                         } else if (fsp->xfer_contig_end == offset) {
1446                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1447                         } else {
1448                                 offset = fsp->xfer_contig_end;
1449                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1450                         }
1451                         fc_fcp_srr(fsp, r_ctl, offset);
1452                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1453
1454                         /*
1455                          * The remote port has the initiative, so just
1456                          * keep waiting for it to complete.
1457                          */
1458                         fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1459                 } else {
1460
1461                         /*
1462                          * The exchange is incomplete, we have seq. initiative.
1463                          * Lost response with requested confirmation,
1464                          * lost confirmation, lost transfer ready or
1465                          * lost write data.
1466                          *
1467                          * For output, if not all data was received, ask
1468                          * for transfer ready to be repeated.
1469                          *
1470                          * If we received or sent all the data, send SRR to
1471                          * request response.
1472                          *
1473                          * If we lost a response, we may have lost some read
1474                          * data as well.
1475                          */
1476                         r_ctl = FC_RCTL_DD_SOL_DATA;
1477                         if (data_dir == DMA_TO_DEVICE) {
1478                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1479                                 if (offset < fsp->data_len)
1480                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1481                         } else if (offset == fsp->xfer_contig_end) {
1482                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1483                         } else if (fsp->xfer_contig_end < offset) {
1484                                 offset = fsp->xfer_contig_end;
1485                         }
1486                         fc_fcp_srr(fsp, r_ctl, offset);
1487                 }
1488         }
1489 unlock_out:
1490         fc_fcp_unlock_pkt(fsp);
1491 out:
1492         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1493         fc_frame_free(fp);
1494 }
1495
1496 /*
1497  * Handle error response or timeout for REC exchange.
1498  */
1499 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1500 {
1501         int error = PTR_ERR(fp);
1502
1503         if (fc_fcp_lock_pkt(fsp))
1504                 goto out;
1505
1506         switch (error) {
1507         case -FC_EX_CLOSED:
1508                 fc_fcp_retry_cmd(fsp);
1509                 break;
1510
1511         default:
1512                 FC_FCP_DBG(fsp, "REC %p fid %x error unexpected error %d\n",
1513                            fsp, fsp->rport->port_id, error);
1514                 fsp->status_code = FC_CMD_PLOGO;
1515                 /* fall through */
1516
1517         case -FC_EX_TIMEOUT:
1518                 /*
1519                  * Assume REC or LS_ACC was lost.
1520                  * The exchange manager will have aborted REC, so retry.
1521                  */
1522                 FC_FCP_DBG(fsp, "REC fid %x error error %d retry %d/%d\n",
1523                            fsp->rport->port_id, error, fsp->recov_retry,
1524                            FC_MAX_RECOV_RETRY);
1525                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1526                         fc_fcp_rec(fsp);
1527                 else
1528                         fc_timeout_error(fsp);
1529                 break;
1530         }
1531         fc_fcp_unlock_pkt(fsp);
1532 out:
1533         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1534 }
1535
1536 /*
1537  * Time out error routine:
1538  * abort's the I/O close the exchange and
1539  * send completion notification to scsi layer
1540  */
1541 static void fc_timeout_error(struct fc_fcp_pkt *fsp)
1542 {
1543         fsp->status_code = FC_CMD_TIME_OUT;
1544         fsp->cdb_status = 0;
1545         fsp->io_status = 0;
1546         /*
1547          * if this fails then we let the scsi command timer fire and
1548          * scsi-ml escalate.
1549          */
1550         fc_fcp_send_abort(fsp);
1551 }
1552
1553 /*
1554  * Sequence retransmission request.
1555  * This is called after receiving status but insufficient data, or
1556  * when expecting status but the request has timed out.
1557  */
1558 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1559 {
1560         struct fc_lport *lp = fsp->lp;
1561         struct fc_rport *rport;
1562         struct fc_rport_libfc_priv *rp;
1563         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1564         struct fc_seq *seq;
1565         struct fcp_srr *srr;
1566         struct fc_frame *fp;
1567         u8 cdb_op;
1568
1569         rport = fsp->rport;
1570         rp = rport->dd_data;
1571         cdb_op = fsp->cdb_cmd.fc_cdb[0];
1572
1573         if (!(rp->flags & FC_RP_FLAGS_RETRY) || rp->rp_state != RPORT_ST_READY)
1574                 goto retry;                     /* shouldn't happen */
1575         fp = fc_frame_alloc(lp, sizeof(*srr));
1576         if (!fp)
1577                 goto retry;
1578
1579         srr = fc_frame_payload_get(fp, sizeof(*srr));
1580         memset(srr, 0, sizeof(*srr));
1581         srr->srr_op = ELS_SRR;
1582         srr->srr_ox_id = htons(ep->oxid);
1583         srr->srr_rx_id = htons(ep->rxid);
1584         srr->srr_r_ctl = r_ctl;
1585         srr->srr_rel_off = htonl(offset);
1586
1587         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1588                        fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1589                        FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1590
1591         seq = lp->tt.exch_seq_send(lp, fp, fc_fcp_srr_resp, NULL,
1592                                    fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
1593         if (!seq) {
1594                 fc_frame_free(fp);
1595                 goto retry;
1596         }
1597         fsp->recov_seq = seq;
1598         fsp->xfer_len = offset;
1599         fsp->xfer_contig_end = offset;
1600         fsp->state &= ~FC_SRB_RCV_STATUS;
1601         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1602         return;
1603 retry:
1604         fc_fcp_retry_cmd(fsp);
1605 }
1606
1607 /*
1608  * Handle response from SRR.
1609  */
1610 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1611 {
1612         struct fc_fcp_pkt *fsp = arg;
1613         struct fc_frame_header *fh;
1614
1615         if (IS_ERR(fp)) {
1616                 fc_fcp_srr_error(fsp, fp);
1617                 return;
1618         }
1619
1620         if (fc_fcp_lock_pkt(fsp))
1621                 goto out;
1622
1623         fh = fc_frame_header_get(fp);
1624         /*
1625          * BUG? fc_fcp_srr_error calls exch_done which would release
1626          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1627          * then fc_exch_timeout would be sending an abort. The exch_done
1628          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1629          * an abort response though.
1630          */
1631         if (fh->fh_type == FC_TYPE_BLS) {
1632                 fc_fcp_unlock_pkt(fsp);
1633                 return;
1634         }
1635
1636         fsp->recov_seq = NULL;
1637         switch (fc_frame_payload_op(fp)) {
1638         case ELS_LS_ACC:
1639                 fsp->recov_retry = 0;
1640                 fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1641                 break;
1642         case ELS_LS_RJT:
1643         default:
1644                 fc_timeout_error(fsp);
1645                 break;
1646         }
1647         fc_fcp_unlock_pkt(fsp);
1648         fsp->lp->tt.exch_done(seq);
1649 out:
1650         fc_frame_free(fp);
1651         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1652 }
1653
1654 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1655 {
1656         if (fc_fcp_lock_pkt(fsp))
1657                 goto out;
1658         fsp->lp->tt.exch_done(fsp->recov_seq);
1659         fsp->recov_seq = NULL;
1660         switch (PTR_ERR(fp)) {
1661         case -FC_EX_TIMEOUT:
1662                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1663                         fc_fcp_rec(fsp);
1664                 else
1665                         fc_timeout_error(fsp);
1666                 break;
1667         case -FC_EX_CLOSED:                     /* e.g., link failure */
1668                 /* fall through */
1669         default:
1670                 fc_fcp_retry_cmd(fsp);
1671                 break;
1672         }
1673         fc_fcp_unlock_pkt(fsp);
1674 out:
1675         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding SRR */
1676 }
1677
1678 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp)
1679 {
1680         /* lock ? */
1681         return (lp->state == LPORT_ST_READY) && lp->link_up && !lp->qfull;
1682 }
1683
1684 /**
1685  * fc_queuecommand - The queuecommand function of the scsi template
1686  * @cmd:        struct scsi_cmnd to be executed
1687  * @done:       Callback function to be called when cmd is completed
1688  *
1689  * this is the i/o strategy routine, called by the scsi layer
1690  * this routine is called with holding the host_lock.
1691  */
1692 int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1693 {
1694         struct fc_lport *lp;
1695         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1696         struct fc_fcp_pkt *fsp;
1697         struct fc_rport_libfc_priv *rp;
1698         int rval;
1699         int rc = 0;
1700         struct fcoe_dev_stats *stats;
1701
1702         lp = shost_priv(sc_cmd->device->host);
1703
1704         rval = fc_remote_port_chkready(rport);
1705         if (rval) {
1706                 sc_cmd->result = rval;
1707                 done(sc_cmd);
1708                 goto out;
1709         }
1710
1711         if (!*(struct fc_remote_port **)rport->dd_data) {
1712                 /*
1713                  * rport is transitioning from blocked/deleted to
1714                  * online
1715                  */
1716                 sc_cmd->result = DID_IMM_RETRY << 16;
1717                 done(sc_cmd);
1718                 goto out;
1719         }
1720
1721         rp = rport->dd_data;
1722
1723         if (!fc_fcp_lport_queue_ready(lp)) {
1724                 rc = SCSI_MLQUEUE_HOST_BUSY;
1725                 goto out;
1726         }
1727
1728         fsp = fc_fcp_pkt_alloc(lp, GFP_ATOMIC);
1729         if (fsp == NULL) {
1730                 rc = SCSI_MLQUEUE_HOST_BUSY;
1731                 goto out;
1732         }
1733
1734         /*
1735          * build the libfc request pkt
1736          */
1737         fsp->cmd = sc_cmd;      /* save the cmd */
1738         fsp->lp = lp;           /* save the softc ptr */
1739         fsp->rport = rport;     /* set the remote port ptr */
1740         sc_cmd->scsi_done = done;
1741
1742         /*
1743          * set up the transfer length
1744          */
1745         fsp->data_len = scsi_bufflen(sc_cmd);
1746         fsp->xfer_len = 0;
1747
1748         /*
1749          * setup the data direction
1750          */
1751         stats = fc_lport_get_stats(lp);
1752         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1753                 fsp->req_flags = FC_SRB_READ;
1754                 stats->InputRequests++;
1755                 stats->InputMegabytes = fsp->data_len;
1756         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1757                 fsp->req_flags = FC_SRB_WRITE;
1758                 stats->OutputRequests++;
1759                 stats->OutputMegabytes = fsp->data_len;
1760         } else {
1761                 fsp->req_flags = 0;
1762                 stats->ControlRequests++;
1763         }
1764
1765         fsp->tgt_flags = rp->flags;
1766
1767         init_timer(&fsp->timer);
1768         fsp->timer.data = (unsigned long)fsp;
1769
1770         /*
1771          * send it to the lower layer
1772          * if we get -1 return then put the request in the pending
1773          * queue.
1774          */
1775         rval = fc_fcp_pkt_send(lp, fsp);
1776         if (rval != 0) {
1777                 fsp->state = FC_SRB_FREE;
1778                 fc_fcp_pkt_release(fsp);
1779                 rc = SCSI_MLQUEUE_HOST_BUSY;
1780         }
1781 out:
1782         return rc;
1783 }
1784 EXPORT_SYMBOL(fc_queuecommand);
1785
1786 /**
1787  * fc_io_compl() -  Handle responses for completed commands
1788  * @fsp:        scsi packet
1789  *
1790  * Translates a error to a Linux SCSI error.
1791  *
1792  * The fcp packet lock must be held when calling.
1793  */
1794 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1795 {
1796         struct fc_fcp_internal *si;
1797         struct scsi_cmnd *sc_cmd;
1798         struct fc_lport *lp;
1799         unsigned long flags;
1800
1801         /* release outstanding ddp context */
1802         fc_fcp_ddp_done(fsp);
1803
1804         fsp->state |= FC_SRB_COMPL;
1805         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1806                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1807                 del_timer_sync(&fsp->timer);
1808                 spin_lock_bh(&fsp->scsi_pkt_lock);
1809         }
1810
1811         lp = fsp->lp;
1812         si = fc_get_scsi_internal(lp);
1813         spin_lock_irqsave(lp->host->host_lock, flags);
1814         if (!fsp->cmd) {
1815                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1816                 return;
1817         }
1818
1819         /*
1820          * if a command timed out while we had to try and throttle IO
1821          * and it is now getting cleaned up, then we are about to
1822          * try again so clear the throttled flag incase we get more
1823          * time outs.
1824          */
1825         if (si->throttled && fsp->state & FC_SRB_NOMEM)
1826                 si->throttled = 0;
1827
1828         sc_cmd = fsp->cmd;
1829         fsp->cmd = NULL;
1830
1831         if (!sc_cmd->SCp.ptr) {
1832                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1833                 return;
1834         }
1835
1836         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1837         switch (fsp->status_code) {
1838         case FC_COMPLETE:
1839                 if (fsp->cdb_status == 0) {
1840                         /*
1841                          * good I/O status
1842                          */
1843                         sc_cmd->result = DID_OK << 16;
1844                         if (fsp->scsi_resid)
1845                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1846                 } else if (fsp->cdb_status == QUEUE_FULL) {
1847                         struct scsi_device *tmp_sdev;
1848                         struct scsi_device *sdev = sc_cmd->device;
1849
1850                         shost_for_each_device(tmp_sdev, sdev->host) {
1851                                 if (tmp_sdev->id != sdev->id)
1852                                         continue;
1853
1854                                 if (tmp_sdev->queue_depth > 1) {
1855                                         scsi_track_queue_full(tmp_sdev,
1856                                                               tmp_sdev->
1857                                                               queue_depth - 1);
1858                                 }
1859                         }
1860                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1861                 } else {
1862                         /*
1863                          * transport level I/O was ok but scsi
1864                          * has non zero status
1865                          */
1866                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1867                 }
1868                 break;
1869         case FC_ERROR:
1870                 sc_cmd->result = DID_ERROR << 16;
1871                 break;
1872         case FC_DATA_UNDRUN:
1873                 if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1874                         /*
1875                          * scsi status is good but transport level
1876                          * underrun.
1877                          */
1878                         sc_cmd->result = DID_OK << 16;
1879                 } else {
1880                         /*
1881                          * scsi got underrun, this is an error
1882                          */
1883                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1884                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1885                 }
1886                 break;
1887         case FC_DATA_OVRRUN:
1888                 /*
1889                  * overrun is an error
1890                  */
1891                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1892                 break;
1893         case FC_CMD_ABORTED:
1894                 sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1895                 break;
1896         case FC_CMD_TIME_OUT:
1897                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1898                 break;
1899         case FC_CMD_RESET:
1900                 sc_cmd->result = (DID_RESET << 16);
1901                 break;
1902         case FC_HRD_ERROR:
1903                 sc_cmd->result = (DID_NO_CONNECT << 16);
1904                 break;
1905         default:
1906                 sc_cmd->result = (DID_ERROR << 16);
1907                 break;
1908         }
1909
1910         list_del(&fsp->list);
1911         sc_cmd->SCp.ptr = NULL;
1912         sc_cmd->scsi_done(sc_cmd);
1913         spin_unlock_irqrestore(lp->host->host_lock, flags);
1914
1915         /* release ref from initial allocation in queue command */
1916         fc_fcp_pkt_release(fsp);
1917 }
1918
1919 /**
1920  * fc_fcp_complete() - complete processing of a fcp packet
1921  * @fsp:        fcp packet
1922  *
1923  * This function may sleep if a fsp timer is pending.
1924  * The host lock must not be held by caller.
1925  */
1926 void fc_fcp_complete(struct fc_fcp_pkt *fsp)
1927 {
1928         if (fc_fcp_lock_pkt(fsp))
1929                 return;
1930
1931         fc_fcp_complete_locked(fsp);
1932         fc_fcp_unlock_pkt(fsp);
1933 }
1934 EXPORT_SYMBOL(fc_fcp_complete);
1935
1936 /**
1937  * fc_eh_abort() - Abort a command
1938  * @sc_cmd:     scsi command to abort
1939  *
1940  * From scsi host template.
1941  * send ABTS to the target device  and wait for the response
1942  * sc_cmd is the pointer to the command to be aborted.
1943  */
1944 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
1945 {
1946         struct fc_fcp_pkt *fsp;
1947         struct fc_lport *lp;
1948         int rc = FAILED;
1949         unsigned long flags;
1950
1951         lp = shost_priv(sc_cmd->device->host);
1952         if (lp->state != LPORT_ST_READY)
1953                 return rc;
1954         else if (!lp->link_up)
1955                 return rc;
1956
1957         spin_lock_irqsave(lp->host->host_lock, flags);
1958         fsp = CMD_SP(sc_cmd);
1959         if (!fsp) {
1960                 /* command completed while scsi eh was setting up */
1961                 spin_unlock_irqrestore(lp->host->host_lock, flags);
1962                 return SUCCESS;
1963         }
1964         /* grab a ref so the fsp and sc_cmd cannot be relased from under us */
1965         fc_fcp_pkt_hold(fsp);
1966         spin_unlock_irqrestore(lp->host->host_lock, flags);
1967
1968         if (fc_fcp_lock_pkt(fsp)) {
1969                 /* completed while we were waiting for timer to be deleted */
1970                 rc = SUCCESS;
1971                 goto release_pkt;
1972         }
1973
1974         rc = fc_fcp_pkt_abort(lp, fsp);
1975         fc_fcp_unlock_pkt(fsp);
1976
1977 release_pkt:
1978         fc_fcp_pkt_release(fsp);
1979         return rc;
1980 }
1981 EXPORT_SYMBOL(fc_eh_abort);
1982
1983 /**
1984  * fc_eh_device_reset() Reset a single LUN
1985  * @sc_cmd:     scsi command
1986  *
1987  * Set from scsi host template to send tm cmd to the target and wait for the
1988  * response.
1989  */
1990 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
1991 {
1992         struct fc_lport *lp;
1993         struct fc_fcp_pkt *fsp;
1994         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1995         int rc = FAILED;
1996         struct fc_rport_libfc_priv *rp;
1997         int rval;
1998
1999         rval = fc_remote_port_chkready(rport);
2000         if (rval)
2001                 goto out;
2002
2003         rp = rport->dd_data;
2004         lp = shost_priv(sc_cmd->device->host);
2005
2006         if (lp->state != LPORT_ST_READY)
2007                 return rc;
2008
2009         FC_SCSI_DBG(lp, "Resetting rport (%6x)\n", rport->port_id);
2010
2011         fsp = fc_fcp_pkt_alloc(lp, GFP_NOIO);
2012         if (fsp == NULL) {
2013                 printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2014                 sc_cmd->result = DID_NO_CONNECT << 16;
2015                 goto out;
2016         }
2017
2018         /*
2019          * Build the libfc request pkt. Do not set the scsi cmnd, because
2020          * the sc passed in is not setup for execution like when sent
2021          * through the queuecommand callout.
2022          */
2023         fsp->lp = lp;           /* save the softc ptr */
2024         fsp->rport = rport;     /* set the remote port ptr */
2025
2026         /*
2027          * flush outstanding commands
2028          */
2029         rc = fc_lun_reset(lp, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2030         fsp->state = FC_SRB_FREE;
2031         fc_fcp_pkt_release(fsp);
2032
2033 out:
2034         return rc;
2035 }
2036 EXPORT_SYMBOL(fc_eh_device_reset);
2037
2038 /**
2039  * fc_eh_host_reset() - The reset function will reset the ports on the host.
2040  * @sc_cmd:     scsi command
2041  */
2042 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2043 {
2044         struct Scsi_Host *shost = sc_cmd->device->host;
2045         struct fc_lport *lp = shost_priv(shost);
2046         unsigned long wait_tmo;
2047
2048         FC_SCSI_DBG(lp, "Resetting host\n");
2049
2050         lp->tt.lport_reset(lp);
2051         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2052         while (!fc_fcp_lport_queue_ready(lp) && time_before(jiffies, wait_tmo))
2053                 msleep(1000);
2054
2055         if (fc_fcp_lport_queue_ready(lp)) {
2056                 shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2057                              "on port (%6x)\n", fc_host_port_id(lp->host));
2058                 return SUCCESS;
2059         } else {
2060                 shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2061                              "port (%6x) is not ready.\n",
2062                              fc_host_port_id(lp->host));
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 "libfc: Leaked SCSI packets when destroying "
2122                        "port (%6x)\n", fc_host_port_id(lp->host));
2123
2124         mempool_destroy(si->scsi_pkt_pool);
2125         kfree(si);
2126         lp->scsi_priv = NULL;
2127 }
2128 EXPORT_SYMBOL(fc_fcp_destroy);
2129
2130 int fc_fcp_init(struct fc_lport *lp)
2131 {
2132         int rc;
2133         struct fc_fcp_internal *si;
2134
2135         if (!lp->tt.fcp_cmd_send)
2136                 lp->tt.fcp_cmd_send = fc_fcp_cmd_send;
2137
2138         if (!lp->tt.fcp_cleanup)
2139                 lp->tt.fcp_cleanup = fc_fcp_cleanup;
2140
2141         if (!lp->tt.fcp_abort_io)
2142                 lp->tt.fcp_abort_io = fc_fcp_abort_io;
2143
2144         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2145         if (!si)
2146                 return -ENOMEM;
2147         lp->scsi_priv = si;
2148         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2149
2150         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2151         if (!si->scsi_pkt_pool) {
2152                 rc = -ENOMEM;
2153                 goto free_internal;
2154         }
2155         return 0;
2156
2157 free_internal:
2158         kfree(si);
2159         return rc;
2160 }
2161 EXPORT_SYMBOL(fc_fcp_init);
2162
2163 static int __init libfc_init(void)
2164 {
2165         int rc;
2166
2167         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2168                                             sizeof(struct fc_fcp_pkt),
2169                                             0, SLAB_HWCACHE_ALIGN, NULL);
2170         if (scsi_pkt_cachep == NULL) {
2171                 printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2172                        "module load failed!");
2173                 return -ENOMEM;
2174         }
2175
2176         rc = fc_setup_exch_mgr();
2177         if (rc)
2178                 goto destroy_pkt_cache;
2179
2180         rc = fc_setup_rport();
2181         if (rc)
2182                 goto destroy_em;
2183
2184         return rc;
2185 destroy_em:
2186         fc_destroy_exch_mgr();
2187 destroy_pkt_cache:
2188         kmem_cache_destroy(scsi_pkt_cachep);
2189         return rc;
2190 }
2191
2192 static void __exit libfc_exit(void)
2193 {
2194         kmem_cache_destroy(scsi_pkt_cachep);
2195         fc_destroy_exch_mgr();
2196         fc_destroy_rport();
2197 }
2198
2199 module_init(libfc_init);
2200 module_exit(libfc_exit);