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 #include <linux/slab.h>
  31
  32 #include <scsi/scsi_tcq.h>
  33 #include <scsi/scsi.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi_device.h>
  36 #include <scsi/scsi_cmnd.h>
  37
  38 #include <scsi/fc/fc_fc2.h>
  39
  40 #include <scsi/libfc.h>
  41 #include <scsi/fc_encode.h>
  42
  43 #include "fc_libfc.h"
  44
  45 static struct kmem_cache *scsi_pkt_cachep;
  46
  47 /* SRB state definitions */
  48 #define FC_SRB_FREE             0               /* cmd is free */
  49 #define FC_SRB_CMD_SENT         (1 << 0)        /* cmd has been sent */
  50 #define FC_SRB_RCV_STATUS       (1 << 1)        /* response has arrived */
  51 #define FC_SRB_ABORT_PENDING    (1 << 2)        /* cmd abort sent to device */
  52 #define FC_SRB_ABORTED          (1 << 3)        /* abort acknowledged */
  53 #define FC_SRB_DISCONTIG        (1 << 4)        /* non-sequential data recvd */
  54 #define FC_SRB_COMPL            (1 << 5)        /* fc_io_compl has been run */
  55 #define FC_SRB_FCP_PROCESSING_TMO (1 << 6)      /* timer function processing */
  56
  57 #define FC_SRB_READ             (1 << 1)
  58 #define FC_SRB_WRITE            (1 << 0)
  59
  60 /*
  61  * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
  62  */
  63 #define CMD_SP(Cmnd)                ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
  64 #define CMD_ENTRY_STATUS(Cmnd)      ((Cmnd)->SCp.have_data_in)
  65 #define CMD_COMPL_STATUS(Cmnd)      ((Cmnd)->SCp.this_residual)
  66 #define CMD_SCSI_STATUS(Cmnd)       ((Cmnd)->SCp.Status)
  67 #define CMD_RESID_LEN(Cmnd)         ((Cmnd)->SCp.buffers_residual)
  68
  69 /**
  70  * struct fc_fcp_internal - FCP layer internal data
  71  * @scsi_pkt_pool: Memory pool to draw FCP packets from
  72  * @scsi_queue_lock: Protects the scsi_pkt_queue
  73  * @scsi_pkt_queue: Current FCP packets
  74  * @last_can_queue_ramp_down_time: ramp down time
  75  * @last_can_queue_ramp_up_time: ramp up time
  76  * @max_can_queue: max can_queue size
  77  */
  78 struct fc_fcp_internal {
  79         mempool_t               *scsi_pkt_pool;
  80         spinlock_t              scsi_queue_lock;
  81         struct list_head        scsi_pkt_queue;
  82         unsigned long           last_can_queue_ramp_down_time;
  83         unsigned long           last_can_queue_ramp_up_time;
  84         int                     max_can_queue;
  85 };
  86
  87 #define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
  88
  89 /*
  90  * function prototypes
  91  * FC scsi I/O related functions
  92  */
  93 static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  94 static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  95 static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  96 static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  97 static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  98 static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
  99 static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
 100 static void fc_fcp_timeout(struct timer_list *);
 101 static void fc_fcp_rec(struct fc_fcp_pkt *);
 102 static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
 103 static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
 104 static void fc_io_compl(struct fc_fcp_pkt *);
 105
 106 static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
 107 static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
 108 static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
 109
 110 /*
 111  * command status codes
 112  */
 113 #define FC_COMPLETE             0
 114 #define FC_CMD_ABORTED          1
 115 #define FC_CMD_RESET            2
 116 #define FC_CMD_PLOGO            3
 117 #define FC_SNS_RCV              4
 118 #define FC_TRANS_ERR            5
 119 #define FC_DATA_OVRRUN          6
 120 #define FC_DATA_UNDRUN          7
 121 #define FC_ERROR                8
 122 #define FC_HRD_ERROR            9
 123 #define FC_CRC_ERROR            10
 124 #define FC_TIMED_OUT            11
 125 #define FC_TRANS_RESET          12
 126
 127 /*
 128  * Error recovery timeout values.
 129  */
 130 #define FC_SCSI_TM_TOV          (10 * HZ)
 131 #define FC_HOST_RESET_TIMEOUT   (30 * HZ)
 132 #define FC_CAN_QUEUE_PERIOD     (60 * HZ)
 133
 134 #define FC_MAX_ERROR_CNT        5
 135 #define FC_MAX_RECOV_RETRY      3
 136
 137 #define FC_FCP_DFLT_QUEUE_DEPTH 32
 138
 139 /**
 140  * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
 141  * @lport: The local port that the FCP packet is for
 142  * @gfp:   GFP flags for allocation
 143  *
 144  * Return value: fcp_pkt structure or null on allocation failure.
 145  * Context:      Can be called from process context, no lock is required.
 146  */
 147 static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
 148 {
 149         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 150         struct fc_fcp_pkt *fsp;
 151
 152         fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
 153         if (fsp) {
 154                 memset(fsp, 0, sizeof(*fsp));
 155                 fsp->lp = lport;
 156                 fsp->xfer_ddp = FC_XID_UNKNOWN;
 157                 refcount_set(&fsp->ref_cnt, 1);
 158                 timer_setup(&fsp->timer, NULL, 0);
 159                 INIT_LIST_HEAD(&fsp->list);
 160                 spin_lock_init(&fsp->scsi_pkt_lock);
 161         } else {
 162                 per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
 163                 put_cpu();
 164         }
 165         return fsp;
 166 }
 167
 168 /**
 169  * fc_fcp_pkt_release() - Release hold on a fcp_pkt
 170  * @fsp: The FCP packet to be released
 171  *
 172  * Context: Can be called from process or interrupt context,
 173  *          no lock is required.
 174  */
 175 static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
 176 {
 177         if (refcount_dec_and_test(&fsp->ref_cnt)) {
 178                 struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 179
 180                 mempool_free(fsp, si->scsi_pkt_pool);
 181         }
 182 }
 183
 184 /**
 185  * fc_fcp_pkt_hold() - Hold a fcp_pkt
 186  * @fsp: The FCP packet to be held
 187  */
 188 static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
 189 {
 190         refcount_inc(&fsp->ref_cnt);
 191 }
 192
 193 /**
 194  * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
 195  * @seq: The sequence that the FCP packet is on (required by destructor API)
 196  * @fsp: The FCP packet to be released
 197  *
 198  * This routine is called by a destructor callback in the fc_exch_seq_send()
 199  * routine of the libfc Transport Template. The 'struct fc_seq' is a required
 200  * argument even though it is not used by this routine.
 201  *
 202  * Context: No locking required.
 203  */
 204 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 205 {
 206         fc_fcp_pkt_release(fsp);
 207 }
 208
 209 /**
 210  * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
 211  * @fsp: The FCP packet to be locked and incremented
 212  *
 213  * We should only return error if we return a command to SCSI-ml before
 214  * getting a response. This can happen in cases where we send a abort, but
 215  * do not wait for the response and the abort and command can be passing
 216  * each other on the wire/network-layer.
 217  *
 218  * Note: this function locks the packet and gets a reference to allow
 219  * callers to call the completion function while the lock is held and
 220  * not have to worry about the packets refcount.
 221  *
 222  * TODO: Maybe we should just have callers grab/release the lock and
 223  * have a function that they call to verify the fsp and grab a ref if
 224  * needed.
 225  */
 226 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 227 {
 228         spin_lock_bh(&fsp->scsi_pkt_lock);
 229         if (fsp->state & FC_SRB_COMPL) {
 230                 spin_unlock_bh(&fsp->scsi_pkt_lock);
 231                 return -EPERM;
 232         }
 233
 234         fc_fcp_pkt_hold(fsp);
 235         return 0;
 236 }
 237
 238 /**
 239  * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
 240  *                       reference count
 241  * @fsp: The FCP packet to be unlocked and decremented
 242  */
 243 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 244 {
 245         spin_unlock_bh(&fsp->scsi_pkt_lock);
 246         fc_fcp_pkt_release(fsp);
 247 }
 248
 249 /**
 250  * fc_fcp_timer_set() - Start a timer for a fcp_pkt
 251  * @fsp:   The FCP packet to start a timer for
 252  * @delay: The timeout period in jiffies
 253  */
 254 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 255 {
 256         if (!(fsp->state & FC_SRB_COMPL)) {
 257                 mod_timer(&fsp->timer, jiffies + delay);
 258                 fsp->timer_delay = delay;
 259         }
 260 }
 261
 262 static void fc_fcp_abort_done(struct fc_fcp_pkt *fsp)
 263 {
 264         fsp->state |= FC_SRB_ABORTED;
 265         fsp->state &= ~FC_SRB_ABORT_PENDING;
 266
 267         if (fsp->wait_for_comp)
 268                 complete(&fsp->tm_done);
 269         else
 270                 fc_fcp_complete_locked(fsp);
 271 }
 272
 273 /**
 274  * fc_fcp_send_abort() - Send an abort for exchanges associated with a
 275  *                       fcp_pkt
 276  * @fsp: The FCP packet to abort exchanges on
 277  */
 278 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 279 {
 280         int rc;
 281
 282         if (!fsp->seq_ptr)
 283                 return -EINVAL;
 284
 285         per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
 286         put_cpu();
 287
 288         fsp->state |= FC_SRB_ABORT_PENDING;
 289         rc = fc_seq_exch_abort(fsp->seq_ptr, 0);
 290         /*
 291          * fc_seq_exch_abort() might return -ENXIO if
 292          * the sequence is already completed
 293          */
 294         if (rc == -ENXIO) {
 295                 fc_fcp_abort_done(fsp);
 296                 rc = 0;
 297         }
 298         return rc;
 299 }
 300
 301 /**
 302  * fc_fcp_retry_cmd() - Retry a fcp_pkt
 303  * @fsp: The FCP packet to be retried
 304  *
 305  * Sets the status code to be FC_ERROR and then calls
 306  * fc_fcp_complete_locked() which in turn calls fc_io_compl().
 307  * fc_io_compl() will notify the SCSI-ml that the I/O is done.
 308  * The SCSI-ml will retry the command.
 309  */
 310 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp, int status_code)
 311 {
 312         if (fsp->seq_ptr) {
 313                 fc_exch_done(fsp->seq_ptr);
 314                 fsp->seq_ptr = NULL;
 315         }
 316
 317         fsp->state &= ~FC_SRB_ABORT_PENDING;
 318         fsp->io_status = 0;
 319         fsp->status_code = status_code;
 320         fc_fcp_complete_locked(fsp);
 321 }
 322
 323 /**
 324  * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
 325  * @fsp: The FCP packet that will manage the DDP frames
 326  * @xid: The XID that will be used for the DDP exchange
 327  */
 328 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
 329 {
 330         struct fc_lport *lport;
 331
 332         lport = fsp->lp;
 333         if ((fsp->req_flags & FC_SRB_READ) &&
 334             (lport->lro_enabled) && (lport->tt.ddp_setup)) {
 335                 if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
 336                                         scsi_sg_count(fsp->cmd)))
 337                         fsp->xfer_ddp = xid;
 338         }
 339 }
 340
 341 /**
 342  * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
 343  *                     DDP related resources for a fcp_pkt
 344  * @fsp: The FCP packet that DDP had been used on
 345  */
 346 void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
 347 {
 348         struct fc_lport *lport;
 349
 350         if (!fsp)
 351                 return;
 352
 353         if (fsp->xfer_ddp == FC_XID_UNKNOWN)
 354                 return;
 355
 356         lport = fsp->lp;
 357         if (lport->tt.ddp_done) {
 358                 fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
 359                 fsp->xfer_ddp = FC_XID_UNKNOWN;
 360         }
 361 }
 362
 363 /**
 364  * fc_fcp_can_queue_ramp_up() - increases can_queue
 365  * @lport: lport to ramp up can_queue
 366  */
 367 static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
 368 {
 369         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 370         unsigned long flags;
 371         int can_queue;
 372
 373         spin_lock_irqsave(lport->host->host_lock, flags);
 374
 375         if (si->last_can_queue_ramp_up_time &&
 376             (time_before(jiffies, si->last_can_queue_ramp_up_time +
 377                          FC_CAN_QUEUE_PERIOD)))
 378                 goto unlock;
 379
 380         if (time_before(jiffies, si->last_can_queue_ramp_down_time +
 381                         FC_CAN_QUEUE_PERIOD))
 382                 goto unlock;
 383
 384         si->last_can_queue_ramp_up_time = jiffies;
 385
 386         can_queue = lport->host->can_queue << 1;
 387         if (can_queue >= si->max_can_queue) {
 388                 can_queue = si->max_can_queue;
 389                 si->last_can_queue_ramp_down_time = 0;
 390         }
 391         lport->host->can_queue = can_queue;
 392         shost_printk(KERN_ERR, lport->host, "libfc: increased "
 393                      "can_queue to %d.\n", can_queue);
 394
 395 unlock:
 396         spin_unlock_irqrestore(lport->host->host_lock, flags);
 397 }
 398
 399 /**
 400  * fc_fcp_can_queue_ramp_down() - reduces can_queue
 401  * @lport: lport to reduce can_queue
 402  *
 403  * If we are getting memory allocation failures, then we may
 404  * be trying to execute too many commands. We let the running
 405  * commands complete or timeout, then try again with a reduced
 406  * can_queue. Eventually we will hit the point where we run
 407  * on all reserved structs.
 408  */
 409 static bool fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
 410 {
 411         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 412         unsigned long flags;
 413         int can_queue;
 414         bool changed = false;
 415
 416         spin_lock_irqsave(lport->host->host_lock, flags);
 417
 418         if (si->last_can_queue_ramp_down_time &&
 419             (time_before(jiffies, si->last_can_queue_ramp_down_time +
 420                          FC_CAN_QUEUE_PERIOD)))
 421                 goto unlock;
 422
 423         si->last_can_queue_ramp_down_time = jiffies;
 424
 425         can_queue = lport->host->can_queue;
 426         can_queue >>= 1;
 427         if (!can_queue)
 428                 can_queue = 1;
 429         lport->host->can_queue = can_queue;
 430         changed = true;
 431
 432 unlock:
 433         spin_unlock_irqrestore(lport->host->host_lock, flags);
 434         return changed;
 435 }
 436
 437 /*
 438  * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
 439  * @lport:      fc lport struct
 440  * @len:        payload length
 441  *
 442  * Allocates fc_frame structure and buffer but if fails to allocate
 443  * then reduce can_queue.
 444  */
 445 static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
 446                                                   size_t len)
 447 {
 448         struct fc_frame *fp;
 449
 450         fp = fc_frame_alloc(lport, len);
 451         if (likely(fp))
 452                 return fp;
 453
 454         per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
 455         put_cpu();
 456         /* error case */
 457         fc_fcp_can_queue_ramp_down(lport);
 458         shost_printk(KERN_ERR, lport->host,
 459                      "libfc: Could not allocate frame, "
 460                      "reducing can_queue to %d.\n", lport->host->can_queue);
 461         return NULL;
 462 }
 463
 464 /**
 465  * get_fsp_rec_tov() - Helper function to get REC_TOV
 466  * @fsp: the FCP packet
 467  *
 468  * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
 469  */
 470 static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
 471 {
 472         struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
 473         unsigned int e_d_tov = FC_DEF_E_D_TOV;
 474
 475         if (rpriv && rpriv->e_d_tov > e_d_tov)
 476                 e_d_tov = rpriv->e_d_tov;
 477         return msecs_to_jiffies(e_d_tov) + HZ;
 478 }
 479
 480 /**
 481  * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
 482  * @fsp: The FCP packet the data is on
 483  * @fp:  The data frame
 484  */
 485 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 486 {
 487         struct scsi_cmnd *sc = fsp->cmd;
 488         struct fc_lport *lport = fsp->lp;
 489         struct fc_stats *stats;
 490         struct fc_frame_header *fh;
 491         size_t start_offset;
 492         size_t offset;
 493         u32 crc;
 494         u32 copy_len = 0;
 495         size_t len;
 496         void *buf;
 497         struct scatterlist *sg;
 498         u32 nents;
 499         u8 host_bcode = FC_COMPLETE;
 500
 501         fh = fc_frame_header_get(fp);
 502         offset = ntohl(fh->fh_parm_offset);
 503         start_offset = offset;
 504         len = fr_len(fp) - sizeof(*fh);
 505         buf = fc_frame_payload_get(fp, 0);
 506
 507         /*
 508          * if this I/O is ddped then clear it and initiate recovery since data
 509          * frames are expected to be placed directly in that case.
 510          *
 511          * Indicate error to scsi-ml because something went wrong with the
 512          * ddp handling to get us here.
 513          */
 514         if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
 515                 fc_fcp_ddp_done(fsp);
 516                 FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
 517                 host_bcode = FC_ERROR;
 518                 goto err;
 519         }
 520         if (offset + len > fsp->data_len) {
 521                 /* this should never happen */
 522                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 523                     fc_frame_crc_check(fp))
 524                         goto crc_err;
 525                 FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
 526                            "data_len %x\n", len, offset, fsp->data_len);
 527
 528                 /* Data is corrupted indicate scsi-ml should retry */
 529                 host_bcode = FC_DATA_OVRRUN;
 530                 goto err;
 531         }
 532         if (offset != fsp->xfer_len)
 533                 fsp->state |= FC_SRB_DISCONTIG;
 534
 535         sg = scsi_sglist(sc);
 536         nents = scsi_sg_count(sc);
 537
 538         if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
 539                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 540                                                     &offset, NULL);
 541         } else {
 542                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 543                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 544                                                     &offset, &crc);
 545                 buf = fc_frame_payload_get(fp, 0);
 546                 if (len % 4)
 547                         crc = crc32(crc, buf + len, 4 - (len % 4));
 548
 549                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 550 crc_err:
 551                         stats = per_cpu_ptr(lport->stats, get_cpu());
 552                         stats->ErrorFrames++;
 553                         /* per cpu count, not total count, but OK for limit */
 554                         if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
 555                                 printk(KERN_WARNING "libfc: CRC error on data "
 556                                        "frame for port (%6.6x)\n",
 557                                        lport->port_id);
 558                         put_cpu();
 559                         /*
 560                          * Assume the frame is total garbage.
 561                          * We may have copied it over the good part
 562                          * of the buffer.
 563                          * If so, we need to retry the entire operation.
 564                          * Otherwise, ignore it.
 565                          */
 566                         if (fsp->state & FC_SRB_DISCONTIG) {
 567                                 host_bcode = FC_CRC_ERROR;
 568                                 goto err;
 569                         }
 570                         return;
 571                 }
 572         }
 573
 574         if (fsp->xfer_contig_end == start_offset)
 575                 fsp->xfer_contig_end += copy_len;
 576         fsp->xfer_len += copy_len;
 577
 578         /*
 579          * In the very rare event that this data arrived after the response
 580          * and completes the transfer, call the completion handler.
 581          */
 582         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 583             fsp->xfer_len == fsp->data_len - fsp->scsi_resid) {
 584                 FC_FCP_DBG( fsp, "complete out-of-order sequence\n" );
 585                 fc_fcp_complete_locked(fsp);
 586         }
 587         return;
 588 err:
 589         fc_fcp_recovery(fsp, host_bcode);
 590 }
 591
 592 /**
 593  * fc_fcp_send_data() - Send SCSI data to a target
 594  * @fsp:      The FCP packet the data is on
 595  * @sp:       The sequence the data is to be sent on
 596  * @offset:   The starting offset for this data request
 597  * @seq_blen: The burst length for this data request
 598  *
 599  * Called after receiving a Transfer Ready data descriptor.
 600  * If the LLD is capable of sequence offload then send down the
 601  * seq_blen amount of data in single frame, otherwise send
 602  * multiple frames of the maximum frame payload supported by
 603  * the target port.
 604  */
 605 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 606                             size_t offset, size_t seq_blen)
 607 {
 608         struct fc_exch *ep;
 609         struct scsi_cmnd *sc;
 610         struct scatterlist *sg;
 611         struct fc_frame *fp = NULL;
 612         struct fc_lport *lport = fsp->lp;
 613         struct page *page;
 614         size_t remaining;
 615         size_t t_blen;
 616         size_t tlen;
 617         size_t sg_bytes;
 618         size_t frame_offset, fh_parm_offset;
 619         size_t off;
 620         int error;
 621         void *data = NULL;
 622         void *page_addr;
 623         int using_sg = lport->sg_supp;
 624         u32 f_ctl;
 625
 626         WARN_ON(seq_blen <= 0);
 627         if (unlikely(offset + seq_blen > fsp->data_len)) {
 628                 /* this should never happen */
 629                 FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
 630                            "offset %zx\n", seq_blen, offset);
 631                 fc_fcp_send_abort(fsp);
 632                 return 0;
 633         } else if (offset != fsp->xfer_len) {
 634                 /* Out of Order Data Request - no problem, but unexpected. */
 635                 FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
 636                            "seq_blen %zx offset %zx\n", seq_blen, offset);
 637         }
 638
 639         /*
 640          * if LLD is capable of seq_offload then set transport
 641          * burst length (t_blen) to seq_blen, otherwise set t_blen
 642          * to max FC frame payload previously set in fsp->max_payload.
 643          */
 644         t_blen = fsp->max_payload;
 645         if (lport->seq_offload) {
 646                 t_blen = min(seq_blen, (size_t)lport->lso_max);
 647                 FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
 648                            fsp, seq_blen, lport->lso_max, t_blen);
 649         }
 650
 651         if (t_blen > 512)
 652                 t_blen &= ~(512 - 1);   /* round down to block size */
 653         sc = fsp->cmd;
 654
 655         remaining = seq_blen;
 656         fh_parm_offset = frame_offset = offset;
 657         tlen = 0;
 658         seq = fc_seq_start_next(seq);
 659         f_ctl = FC_FC_REL_OFF;
 660         WARN_ON(!seq);
 661
 662         sg = scsi_sglist(sc);
 663
 664         while (remaining > 0 && sg) {
 665                 if (offset >= sg->length) {
 666                         offset -= sg->length;
 667                         sg = sg_next(sg);
 668                         continue;
 669                 }
 670                 if (!fp) {
 671                         tlen = min(t_blen, remaining);
 672
 673                         /*
 674                          * TODO.  Temporary workaround.  fc_seq_send() can't
 675                          * handle odd lengths in non-linear skbs.
 676                          * This will be the final fragment only.
 677                          */
 678                         if (tlen % 4)
 679                                 using_sg = 0;
 680                         fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
 681                         if (!fp)
 682                                 return -ENOMEM;
 683
 684                         data = fc_frame_header_get(fp) + 1;
 685                         fh_parm_offset = frame_offset;
 686                         fr_max_payload(fp) = fsp->max_payload;
 687                 }
 688
 689                 off = offset + sg->offset;
 690                 sg_bytes = min(tlen, sg->length - offset);
 691                 sg_bytes = min(sg_bytes,
 692                                (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
 693                 page = sg_page(sg) + (off >> PAGE_SHIFT);
 694                 if (using_sg) {
 695                         get_page(page);
 696                         skb_fill_page_desc(fp_skb(fp),
 697                                            skb_shinfo(fp_skb(fp))->nr_frags,
 698                                            page, off & ~PAGE_MASK, sg_bytes);
 699                         fp_skb(fp)->data_len += sg_bytes;
 700                         fr_len(fp) += sg_bytes;
 701                         fp_skb(fp)->truesize += PAGE_SIZE;
 702                 } else {
 703                         /*
 704                          * The scatterlist item may be bigger than PAGE_SIZE,
 705                          * but we must not cross pages inside the kmap.
 706                          */
 707                         page_addr = kmap_atomic(page);
 708                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 709                                sg_bytes);
 710                         kunmap_atomic(page_addr);
 711                         data += sg_bytes;
 712                 }
 713                 offset += sg_bytes;
 714                 frame_offset += sg_bytes;
 715                 tlen -= sg_bytes;
 716                 remaining -= sg_bytes;
 717
 718                 if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
 719                     (tlen))
 720                         continue;
 721
 722                 /*
 723                  * Send sequence with transfer sequence initiative in case
 724                  * this is last FCP frame of the sequence.
 725                  */
 726                 if (remaining == 0)
 727                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 728
 729                 ep = fc_seq_exch(seq);
 730                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 731                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
 732
 733                 /*
 734                  * send fragment using for a sequence.
 735                  */
 736                 error = fc_seq_send(lport, seq, fp);
 737                 if (error) {
 738                         WARN_ON(1);             /* send error should be rare */
 739                         return error;
 740                 }
 741                 fp = NULL;
 742         }
 743         fsp->xfer_len += seq_blen;      /* premature count? */
 744         return 0;
 745 }
 746
 747 /**
 748  * fc_fcp_abts_resp() - Receive an ABTS response
 749  * @fsp: The FCP packet that is being aborted
 750  * @fp:  The response frame
 751  */
 752 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 753 {
 754         int ba_done = 1;
 755         struct fc_ba_rjt *brp;
 756         struct fc_frame_header *fh;
 757
 758         fh = fc_frame_header_get(fp);
 759         switch (fh->fh_r_ctl) {
 760         case FC_RCTL_BA_ACC:
 761                 break;
 762         case FC_RCTL_BA_RJT:
 763                 brp = fc_frame_payload_get(fp, sizeof(*brp));
 764                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 765                         break;
 766                 /* fall thru */
 767         default:
 768                 /*
 769                  * we will let the command timeout
 770                  * and scsi-ml recover in this case,
 771                  * therefore cleared the ba_done flag.
 772                  */
 773                 ba_done = 0;
 774         }
 775
 776         if (ba_done)
 777                 fc_fcp_abort_done(fsp);
 778 }
 779
 780 /**
 781  * fc_fcp_recv() - Receive an FCP frame
 782  * @seq: The sequence the frame is on
 783  * @fp:  The received frame
 784  * @arg: The related FCP packet
 785  *
 786  * Context: Called from Soft IRQ context. Can not be called
 787  *          holding the FCP packet list lock.
 788  */
 789 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 790 {
 791         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 792         struct fc_lport *lport = fsp->lp;
 793         struct fc_frame_header *fh;
 794         struct fcp_txrdy *dd;
 795         u8 r_ctl;
 796         int rc = 0;
 797
 798         if (IS_ERR(fp)) {
 799                 fc_fcp_error(fsp, fp);
 800                 return;
 801         }
 802
 803         fh = fc_frame_header_get(fp);
 804         r_ctl = fh->fh_r_ctl;
 805
 806         if (lport->state != LPORT_ST_READY) {
 807                 FC_FCP_DBG(fsp, "lport state %d, ignoring r_ctl %x\n",
 808                            lport->state, r_ctl);
 809                 goto out;
 810         }
 811         if (fc_fcp_lock_pkt(fsp))
 812                 goto out;
 813
 814         if (fh->fh_type == FC_TYPE_BLS) {
 815                 fc_fcp_abts_resp(fsp, fp);
 816                 goto unlock;
 817         }
 818
 819         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING)) {
 820                 FC_FCP_DBG(fsp, "command aborted, ignoring r_ctl %x\n", r_ctl);
 821                 goto unlock;
 822         }
 823
 824         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 825                 /*
 826                  * received XFER RDY from the target
 827                  * need to send data to the target
 828                  */
 829                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 830                 dd = fc_frame_payload_get(fp, sizeof(*dd));
 831                 WARN_ON(!dd);
 832
 833                 rc = fc_fcp_send_data(fsp, seq,
 834                                       (size_t) ntohl(dd->ft_data_ro),
 835                                       (size_t) ntohl(dd->ft_burst_len));
 836                 if (!rc)
 837                         seq->rec_data = fsp->xfer_len;
 838         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 839                 /*
 840                  * received a DATA frame
 841                  * next we will copy the data to the system buffer
 842                  */
 843                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
 844                 fc_fcp_recv_data(fsp, fp);
 845                 seq->rec_data = fsp->xfer_contig_end;
 846         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 847                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 848
 849                 fc_fcp_resp(fsp, fp);
 850         } else {
 851                 FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
 852         }
 853 unlock:
 854         fc_fcp_unlock_pkt(fsp);
 855 out:
 856         fc_frame_free(fp);
 857 }
 858
 859 /**
 860  * fc_fcp_resp() - Handler for FCP responses
 861  * @fsp: The FCP packet the response is for
 862  * @fp:  The response frame
 863  */
 864 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 865 {
 866         struct fc_frame_header *fh;
 867         struct fcp_resp *fc_rp;
 868         struct fcp_resp_ext *rp_ex;
 869         struct fcp_resp_rsp_info *fc_rp_info;
 870         u32 plen;
 871         u32 expected_len;
 872         u32 respl = 0;
 873         u32 snsl = 0;
 874         u8 flags = 0;
 875
 876         plen = fr_len(fp);
 877         fh = (struct fc_frame_header *)fr_hdr(fp);
 878         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 879                 goto len_err;
 880         plen -= sizeof(*fh);
 881         fc_rp = (struct fcp_resp *)(fh + 1);
 882         fsp->cdb_status = fc_rp->fr_status;
 883         flags = fc_rp->fr_flags;
 884         fsp->scsi_comp_flags = flags;
 885         expected_len = fsp->data_len;
 886
 887         /* if ddp, update xfer len */
 888         fc_fcp_ddp_done(fsp);
 889
 890         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 891                 rp_ex = (void *)(fc_rp + 1);
 892                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 893                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 894                                 goto len_err;
 895                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 896                         if (flags & FCP_RSP_LEN_VAL) {
 897                                 respl = ntohl(rp_ex->fr_rsp_len);
 898                                 if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
 899                                     (respl != FCP_RESP_RSP_INFO_LEN8))
 900                                         goto len_err;
 901                                 if (fsp->wait_for_comp) {
 902                                         /* Abuse cdb_status for rsp code */
 903                                         fsp->cdb_status = fc_rp_info->rsp_code;
 904                                         complete(&fsp->tm_done);
 905                                         /*
 906                                          * tmfs will not have any scsi cmd so
 907                                          * exit here
 908                                          */
 909                                         return;
 910                                 }
 911                         }
 912                         if (flags & FCP_SNS_LEN_VAL) {
 913                                 snsl = ntohl(rp_ex->fr_sns_len);
 914                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
 915                                         snsl = SCSI_SENSE_BUFFERSIZE;
 916                                 memcpy(fsp->cmd->sense_buffer,
 917                                        (char *)fc_rp_info + respl, snsl);
 918                         }
 919                 }
 920                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 921                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 922                                 goto len_err;
 923                         if (flags & FCP_RESID_UNDER) {
 924                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 925                                 /*
 926                                  * The cmnd->underflow is the minimum number of
 927                                  * bytes that must be transferred for this
 928                                  * command.  Provided a sense condition is not
 929                                  * present, make sure the actual amount
 930                                  * transferred is at least the underflow value
 931                                  * or fail.
 932                                  */
 933                                 if (!(flags & FCP_SNS_LEN_VAL) &&
 934                                     (fc_rp->fr_status == 0) &&
 935                                     (scsi_bufflen(fsp->cmd) -
 936                                      fsp->scsi_resid) < fsp->cmd->underflow)
 937                                         goto err;
 938                                 expected_len -= fsp->scsi_resid;
 939                         } else {
 940                                 fsp->status_code = FC_ERROR;
 941                         }
 942                 }
 943         }
 944         fsp->state |= FC_SRB_RCV_STATUS;
 945
 946         /*
 947          * Check for missing or extra data frames.
 948          */
 949         if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
 950                      fsp->xfer_len != expected_len)) {
 951                 if (fsp->xfer_len < expected_len) {
 952                         /*
 953                          * Some data may be queued locally,
 954                          * Wait a at least one jiffy to see if it is delivered.
 955                          * If this expires without data, we may do SRR.
 956                          */
 957                         if (fsp->lp->qfull) {
 958                                 FC_FCP_DBG(fsp, "tgt %6.6x queue busy retry\n",
 959                                            fsp->rport->port_id);
 960                                 return;
 961                         }
 962                         FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx data underrun "
 963                                    "len %x, data len %x\n",
 964                                    fsp->rport->port_id,
 965                                    fsp->xfer_len, expected_len, fsp->data_len);
 966                         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
 967                         return;
 968                 }
 969                 fsp->status_code = FC_DATA_OVRRUN;
 970                 FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
 971                            "len %x, data len %x\n",
 972                            fsp->rport->port_id,
 973                            fsp->xfer_len, expected_len, fsp->data_len);
 974         }
 975         fc_fcp_complete_locked(fsp);
 976         return;
 977
 978 len_err:
 979         FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
 980                    "snsl %u\n", flags, fr_len(fp), respl, snsl);
 981 err:
 982         fsp->status_code = FC_ERROR;
 983         fc_fcp_complete_locked(fsp);
 984 }
 985
 986 /**
 987  * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
 988  *                            fcp_pkt lock held
 989  * @fsp: The FCP packet to be completed
 990  *
 991  * This function may sleep if a timer is pending. The packet lock must be
 992  * held, and the host lock must not be held.
 993  */
 994 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 995 {
 996         struct fc_lport *lport = fsp->lp;
 997         struct fc_seq *seq;
 998         struct fc_exch *ep;
 999         u32 f_ctl;
1000
1001         if (fsp->state & FC_SRB_ABORT_PENDING)
1002                 return;
1003
1004         if (fsp->state & FC_SRB_ABORTED) {
1005                 if (!fsp->status_code)
1006                         fsp->status_code = FC_CMD_ABORTED;
1007         } else {
1008                 /*
1009                  * Test for transport underrun, independent of response
1010                  * underrun status.
1011                  */
1012                 if (fsp->cdb_status == SAM_STAT_GOOD &&
1013                     fsp->xfer_len < fsp->data_len && !fsp->io_status &&
1014                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
1015                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
1016                         FC_FCP_DBG(fsp, "data underrun, xfer %zx data %x\n",
1017                                     fsp->xfer_len, fsp->data_len);
1018                         fsp->status_code = FC_DATA_UNDRUN;
1019                 }
1020         }
1021
1022         seq = fsp->seq_ptr;
1023         if (seq) {
1024                 fsp->seq_ptr = NULL;
1025                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
1026                         struct fc_frame *conf_frame;
1027                         struct fc_seq *csp;
1028
1029                         csp = fc_seq_start_next(seq);
1030                         conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
1031                         if (conf_frame) {
1032                                 f_ctl = FC_FC_SEQ_INIT;
1033                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1034                                 ep = fc_seq_exch(seq);
1035                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
1036                                                ep->did, ep->sid,
1037                                                FC_TYPE_FCP, f_ctl, 0);
1038                                 fc_seq_send(lport, csp, conf_frame);
1039                         }
1040                 }
1041                 fc_exch_done(seq);
1042         }
1043         /*
1044          * Some resets driven by SCSI are not I/Os and do not have
1045          * SCSI commands associated with the requests. We should not
1046          * call I/O completion if we do not have a SCSI command.
1047          */
1048         if (fsp->cmd)
1049                 fc_io_compl(fsp);
1050 }
1051
1052 /**
1053  * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
1054  * @fsp:   The FCP packet whose exchanges should be canceled
1055  * @error: The reason for the cancellation
1056  */
1057 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1058 {
1059         if (fsp->seq_ptr) {
1060                 fc_exch_done(fsp->seq_ptr);
1061                 fsp->seq_ptr = NULL;
1062         }
1063         fsp->status_code = error;
1064 }
1065
1066 /**
1067  * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1068  * @lport: The local port whose exchanges should be canceled
1069  * @id:    The target's ID
1070  * @lun:   The LUN
1071  * @error: The reason for cancellation
1072  *
1073  * If lun or id is -1, they are ignored.
1074  */
1075 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1076                                     unsigned int lun, int error)
1077 {
1078         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1079         struct fc_fcp_pkt *fsp;
1080         struct scsi_cmnd *sc_cmd;
1081         unsigned long flags;
1082
1083         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1084 restart:
1085         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1086                 sc_cmd = fsp->cmd;
1087                 if (id != -1 && scmd_id(sc_cmd) != id)
1088                         continue;
1089
1090                 if (lun != -1 && sc_cmd->device->lun != lun)
1091                         continue;
1092
1093                 fc_fcp_pkt_hold(fsp);
1094                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1095
1096                 spin_lock_bh(&fsp->scsi_pkt_lock);
1097                 if (!(fsp->state & FC_SRB_COMPL)) {
1098                         fsp->state |= FC_SRB_COMPL;
1099                         /*
1100                          * TODO: dropping scsi_pkt_lock and then reacquiring
1101                          * again around fc_fcp_cleanup_cmd() is required,
1102                          * since fc_fcp_cleanup_cmd() calls into
1103                          * fc_seq_set_resp() and that func preempts cpu using
1104                          * schedule. May be schedule and related code should be
1105                          * removed instead of unlocking here to avoid scheduling
1106                          * while atomic bug.
1107                          */
1108                         spin_unlock_bh(&fsp->scsi_pkt_lock);
1109
1110                         fc_fcp_cleanup_cmd(fsp, error);
1111
1112                         spin_lock_bh(&fsp->scsi_pkt_lock);
1113                         fc_io_compl(fsp);
1114                 }
1115                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1116
1117                 fc_fcp_pkt_release(fsp);
1118                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1119                 /*
1120                  * while we dropped the lock multiple pkts could
1121                  * have been released, so we have to start over.
1122                  */
1123                 goto restart;
1124         }
1125         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1126 }
1127
1128 /**
1129  * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1130  * @lport: The local port whose exchanges are to be aborted
1131  */
1132 static void fc_fcp_abort_io(struct fc_lport *lport)
1133 {
1134         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1135 }
1136
1137 /**
1138  * fc_fcp_pkt_send() - Send a fcp_pkt
1139  * @lport: The local port to send the FCP packet on
1140  * @fsp:   The FCP packet to send
1141  *
1142  * Return:  Zero for success and -1 for failure
1143  * Locks:   Called without locks held
1144  */
1145 static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1146 {
1147         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1148         unsigned long flags;
1149         int rc;
1150
1151         fsp->cmd->SCp.ptr = (char *)fsp;
1152         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1153         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1154
1155         int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1156         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1157
1158         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1159         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1160         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1161         rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1162         if (unlikely(rc)) {
1163                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1164                 fsp->cmd->SCp.ptr = NULL;
1165                 list_del(&fsp->list);
1166                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1167         }
1168
1169         return rc;
1170 }
1171
1172 /**
1173  * fc_fcp_cmd_send() - Send a FCP command
1174  * @lport: The local port to send the command on
1175  * @fsp:   The FCP packet the command is on
1176  * @resp:  The handler for the response
1177  */
1178 static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1179                            void (*resp)(struct fc_seq *,
1180                                         struct fc_frame *fp,
1181                                         void *arg))
1182 {
1183         struct fc_frame *fp;
1184         struct fc_seq *seq;
1185         struct fc_rport *rport;
1186         struct fc_rport_libfc_priv *rpriv;
1187         const size_t len = sizeof(fsp->cdb_cmd);
1188         int rc = 0;
1189
1190         if (fc_fcp_lock_pkt(fsp))
1191                 return 0;
1192
1193         fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1194         if (!fp) {
1195                 rc = -1;
1196                 goto unlock;
1197         }
1198
1199         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1200         fr_fsp(fp) = fsp;
1201         rport = fsp->rport;
1202         fsp->max_payload = rport->maxframe_size;
1203         rpriv = rport->dd_data;
1204
1205         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1206                        rpriv->local_port->port_id, FC_TYPE_FCP,
1207                        FC_FCTL_REQ, 0);
1208
1209         seq = fc_exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1210         if (!seq) {
1211                 rc = -1;
1212                 goto unlock;
1213         }
1214         fsp->seq_ptr = seq;
1215         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1216
1217         fsp->timer.function = fc_fcp_timeout;
1218         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1219                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1220
1221 unlock:
1222         fc_fcp_unlock_pkt(fsp);
1223         return rc;
1224 }
1225
1226 /**
1227  * fc_fcp_error() - Handler for FCP layer errors
1228  * @fsp: The FCP packet the error is on
1229  * @fp:  The frame that has errored
1230  */
1231 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1232 {
1233         int error = PTR_ERR(fp);
1234
1235         if (fc_fcp_lock_pkt(fsp))
1236                 return;
1237
1238         if (error == -FC_EX_CLOSED) {
1239                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1240                 goto unlock;
1241         }
1242
1243         /*
1244          * clear abort pending, because the lower layer
1245          * decided to force completion.
1246          */
1247         fsp->state &= ~FC_SRB_ABORT_PENDING;
1248         fsp->status_code = FC_CMD_PLOGO;
1249         fc_fcp_complete_locked(fsp);
1250 unlock:
1251         fc_fcp_unlock_pkt(fsp);
1252 }
1253
1254 /**
1255  * fc_fcp_pkt_abort() - Abort a fcp_pkt
1256  * @fsp:   The FCP packet to abort on
1257  *
1258  * Called to send an abort and then wait for abort completion
1259  */
1260 static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1261 {
1262         int rc = FAILED;
1263         unsigned long ticks_left;
1264
1265         FC_FCP_DBG(fsp, "pkt abort state %x\n", fsp->state);
1266         if (fc_fcp_send_abort(fsp)) {
1267                 FC_FCP_DBG(fsp, "failed to send abort\n");
1268                 return FAILED;
1269         }
1270
1271         if (fsp->state & FC_SRB_ABORTED) {
1272                 FC_FCP_DBG(fsp, "target abort cmd  completed\n");
1273                 return SUCCESS;
1274         }
1275
1276         init_completion(&fsp->tm_done);
1277         fsp->wait_for_comp = 1;
1278
1279         spin_unlock_bh(&fsp->scsi_pkt_lock);
1280         ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1281                                                         FC_SCSI_TM_TOV);
1282         spin_lock_bh(&fsp->scsi_pkt_lock);
1283         fsp->wait_for_comp = 0;
1284
1285         if (!ticks_left) {
1286                 FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1287         } else if (fsp->state & FC_SRB_ABORTED) {
1288                 FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1289                 rc = SUCCESS;
1290                 fc_fcp_complete_locked(fsp);
1291         }
1292
1293         return rc;
1294 }
1295
1296 /**
1297  * fc_lun_reset_send() - Send LUN reset command
1298  * @data: The FCP packet that identifies the LUN to be reset
1299  */
1300 static void fc_lun_reset_send(struct timer_list *t)
1301 {
1302         struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1303         struct fc_lport *lport = fsp->lp;
1304
1305         if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1306                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1307                         return;
1308                 if (fc_fcp_lock_pkt(fsp))
1309                         return;
1310                 fsp->timer.function = fc_lun_reset_send;
1311                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1312                 fc_fcp_unlock_pkt(fsp);
1313         }
1314 }
1315
1316 /**
1317  * fc_lun_reset() - Send a LUN RESET command to a device
1318  *                  and wait for the reply
1319  * @lport: The local port to sent the command on
1320  * @fsp:   The FCP packet that identifies the LUN to be reset
1321  * @id:    The SCSI command ID
1322  * @lun:   The LUN ID to be reset
1323  */
1324 static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1325                         unsigned int id, unsigned int lun)
1326 {
1327         int rc;
1328
1329         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1330         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1331         int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1332
1333         fsp->wait_for_comp = 1;
1334         init_completion(&fsp->tm_done);
1335
1336         fc_lun_reset_send(&fsp->timer);
1337
1338         /*
1339          * wait for completion of reset
1340          * after that make sure all commands are terminated
1341          */
1342         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1343
1344         spin_lock_bh(&fsp->scsi_pkt_lock);
1345         fsp->state |= FC_SRB_COMPL;
1346         spin_unlock_bh(&fsp->scsi_pkt_lock);
1347
1348         del_timer_sync(&fsp->timer);
1349
1350         spin_lock_bh(&fsp->scsi_pkt_lock);
1351         if (fsp->seq_ptr) {
1352                 fc_exch_done(fsp->seq_ptr);
1353                 fsp->seq_ptr = NULL;
1354         }
1355         fsp->wait_for_comp = 0;
1356         spin_unlock_bh(&fsp->scsi_pkt_lock);
1357
1358         if (!rc) {
1359                 FC_SCSI_DBG(lport, "lun reset failed\n");
1360                 return FAILED;
1361         }
1362
1363         /* cdb_status holds the tmf's rsp code */
1364         if (fsp->cdb_status != FCP_TMF_CMPL)
1365                 return FAILED;
1366
1367         FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1368         fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1369         return SUCCESS;
1370 }
1371
1372 /**
1373  * fc_tm_done() - Task Management response handler
1374  * @seq: The sequence that the response is on
1375  * @fp:  The response frame
1376  * @arg: The FCP packet the response is for
1377  */
1378 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1379 {
1380         struct fc_fcp_pkt *fsp = arg;
1381         struct fc_frame_header *fh;
1382
1383         if (IS_ERR(fp)) {
1384                 /*
1385                  * If there is an error just let it timeout or wait
1386                  * for TMF to be aborted if it timedout.
1387                  *
1388                  * scsi-eh will escalate for when either happens.
1389                  */
1390                 return;
1391         }
1392
1393         if (fc_fcp_lock_pkt(fsp))
1394                 goto out;
1395
1396         /*
1397          * raced with eh timeout handler.
1398          */
1399         if (!fsp->seq_ptr || !fsp->wait_for_comp)
1400                 goto out_unlock;
1401
1402         fh = fc_frame_header_get(fp);
1403         if (fh->fh_type != FC_TYPE_BLS)
1404                 fc_fcp_resp(fsp, fp);
1405         fsp->seq_ptr = NULL;
1406         fc_exch_done(seq);
1407 out_unlock:
1408         fc_fcp_unlock_pkt(fsp);
1409 out:
1410         fc_frame_free(fp);
1411 }
1412
1413 /**
1414  * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1415  * @lport: The local port to be cleaned up
1416  */
1417 static void fc_fcp_cleanup(struct fc_lport *lport)
1418 {
1419         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1420 }
1421
1422 /**
1423  * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1424  * @data: The FCP packet that has timed out
1425  *
1426  * If REC is supported then just issue it and return. The REC exchange will
1427  * complete or time out and recovery can continue at that point. Otherwise,
1428  * if the response has been received without all the data it has been
1429  * ER_TIMEOUT since the response was received. If the response has not been
1430  * received we see if data was received recently. If it has been then we
1431  * continue waiting, otherwise, we abort the command.
1432  */
1433 static void fc_fcp_timeout(struct timer_list *t)
1434 {
1435         struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1436         struct fc_rport *rport = fsp->rport;
1437         struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1438
1439         if (fc_fcp_lock_pkt(fsp))
1440                 return;
1441
1442         if (fsp->cdb_cmd.fc_tm_flags)
1443                 goto unlock;
1444
1445         if (fsp->lp->qfull) {
1446                 FC_FCP_DBG(fsp, "fcp timeout, resetting timer delay %d\n",
1447                            fsp->timer_delay);
1448                 fsp->timer.function = fc_fcp_timeout;
1449                 fc_fcp_timer_set(fsp, fsp->timer_delay);
1450                 goto unlock;
1451         }
1452         FC_FCP_DBG(fsp, "fcp timeout, delay %d flags %x state %x\n",
1453                    fsp->timer_delay, rpriv->flags, fsp->state);
1454         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1455
1456         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1457                 fc_fcp_rec(fsp);
1458         else if (fsp->state & FC_SRB_RCV_STATUS)
1459                 fc_fcp_complete_locked(fsp);
1460         else
1461                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1462         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1463 unlock:
1464         fc_fcp_unlock_pkt(fsp);
1465 }
1466
1467 /**
1468  * fc_fcp_rec() - Send a REC ELS request
1469  * @fsp: The FCP packet to send the REC request on
1470  */
1471 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1472 {
1473         struct fc_lport *lport;
1474         struct fc_frame *fp;
1475         struct fc_rport *rport;
1476         struct fc_rport_libfc_priv *rpriv;
1477
1478         lport = fsp->lp;
1479         rport = fsp->rport;
1480         rpriv = rport->dd_data;
1481         if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1482                 fsp->status_code = FC_HRD_ERROR;
1483                 fsp->io_status = 0;
1484                 fc_fcp_complete_locked(fsp);
1485                 return;
1486         }
1487
1488         fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1489         if (!fp)
1490                 goto retry;
1491
1492         fr_seq(fp) = fsp->seq_ptr;
1493         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1494                        rpriv->local_port->port_id, FC_TYPE_ELS,
1495                        FC_FCTL_REQ, 0);
1496         if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1497                                  fc_fcp_rec_resp, fsp,
1498                                  2 * lport->r_a_tov)) {
1499                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1500                 return;
1501         }
1502 retry:
1503         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1504                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1505         else
1506                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1507 }
1508
1509 /**
1510  * fc_fcp_rec_resp() - Handler for REC ELS responses
1511  * @seq: The sequence the response is on
1512  * @fp:  The response frame
1513  * @arg: The FCP packet the response is on
1514  *
1515  * If the response is a reject then the scsi layer will handle
1516  * the timeout. If the response is a LS_ACC then if the I/O was not completed
1517  * set the timeout and return. If the I/O was completed then complete the
1518  * exchange and tell the SCSI layer.
1519  */
1520 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1521 {
1522         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1523         struct fc_els_rec_acc *recp;
1524         struct fc_els_ls_rjt *rjt;
1525         u32 e_stat;
1526         u8 opcode;
1527         u32 offset;
1528         enum dma_data_direction data_dir;
1529         enum fc_rctl r_ctl;
1530         struct fc_rport_libfc_priv *rpriv;
1531
1532         if (IS_ERR(fp)) {
1533                 fc_fcp_rec_error(fsp, fp);
1534                 return;
1535         }
1536
1537         if (fc_fcp_lock_pkt(fsp))
1538                 goto out;
1539
1540         fsp->recov_retry = 0;
1541         opcode = fc_frame_payload_op(fp);
1542         if (opcode == ELS_LS_RJT) {
1543                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1544                 switch (rjt->er_reason) {
1545                 default:
1546                         FC_FCP_DBG(fsp,
1547                                    "device %x invalid REC reject %d/%d\n",
1548                                    fsp->rport->port_id, rjt->er_reason,
1549                                    rjt->er_explan);
1550                         /* fall through */
1551                 case ELS_RJT_UNSUP:
1552                         FC_FCP_DBG(fsp, "device does not support REC\n");
1553                         rpriv = fsp->rport->dd_data;
1554                         /*
1555                          * if we do not spport RECs or got some bogus
1556                          * reason then resetup timer so we check for
1557                          * making progress.
1558                          */
1559                         rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1560                         break;
1561                 case ELS_RJT_LOGIC:
1562                 case ELS_RJT_UNAB:
1563                         FC_FCP_DBG(fsp, "device %x REC reject %d/%d\n",
1564                                    fsp->rport->port_id, rjt->er_reason,
1565                                    rjt->er_explan);
1566                         /*
1567                          * If response got lost or is stuck in the
1568                          * queue somewhere we have no idea if and when
1569                          * the response will be received. So quarantine
1570                          * the xid and retry the command.
1571                          */
1572                         if (rjt->er_explan == ELS_EXPL_OXID_RXID) {
1573                                 struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1574                                 ep->state |= FC_EX_QUARANTINE;
1575                                 fsp->state |= FC_SRB_ABORTED;
1576                                 fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1577                                 break;
1578                         }
1579                         fc_fcp_recovery(fsp, FC_TRANS_RESET);
1580                         break;
1581                 }
1582         } else if (opcode == ELS_LS_ACC) {
1583                 if (fsp->state & FC_SRB_ABORTED)
1584                         goto unlock_out;
1585
1586                 data_dir = fsp->cmd->sc_data_direction;
1587                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1588                 offset = ntohl(recp->reca_fc4value);
1589                 e_stat = ntohl(recp->reca_e_stat);
1590
1591                 if (e_stat & ESB_ST_COMPLETE) {
1592
1593                         /*
1594                          * The exchange is complete.
1595                          *
1596                          * For output, we must've lost the response.
1597                          * For input, all data must've been sent.
1598                          * We lost may have lost the response
1599                          * (and a confirmation was requested) and maybe
1600                          * some data.
1601                          *
1602                          * If all data received, send SRR
1603                          * asking for response.  If partial data received,
1604                          * or gaps, SRR requests data at start of gap.
1605                          * Recovery via SRR relies on in-order-delivery.
1606                          */
1607                         if (data_dir == DMA_TO_DEVICE) {
1608                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1609                         } else if (fsp->xfer_contig_end == offset) {
1610                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1611                         } else {
1612                                 offset = fsp->xfer_contig_end;
1613                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1614                         }
1615                         fc_fcp_srr(fsp, r_ctl, offset);
1616                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1617                         /*
1618                          * The remote port has the initiative, so just
1619                          * keep waiting for it to complete.
1620                          */
1621                         fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1622                 } else {
1623
1624                         /*
1625                          * The exchange is incomplete, we have seq. initiative.
1626                          * Lost response with requested confirmation,
1627                          * lost confirmation, lost transfer ready or
1628                          * lost write data.
1629                          *
1630                          * For output, if not all data was received, ask
1631                          * for transfer ready to be repeated.
1632                          *
1633                          * If we received or sent all the data, send SRR to
1634                          * request response.
1635                          *
1636                          * If we lost a response, we may have lost some read
1637                          * data as well.
1638                          */
1639                         r_ctl = FC_RCTL_DD_SOL_DATA;
1640                         if (data_dir == DMA_TO_DEVICE) {
1641                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1642                                 if (offset < fsp->data_len)
1643                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1644                         } else if (offset == fsp->xfer_contig_end) {
1645                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1646                         } else if (fsp->xfer_contig_end < offset) {
1647                                 offset = fsp->xfer_contig_end;
1648                         }
1649                         fc_fcp_srr(fsp, r_ctl, offset);
1650                 }
1651         }
1652 unlock_out:
1653         fc_fcp_unlock_pkt(fsp);
1654 out:
1655         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1656         fc_frame_free(fp);
1657 }
1658
1659 /**
1660  * fc_fcp_rec_error() - Handler for REC errors
1661  * @fsp: The FCP packet the error is on
1662  * @fp:  The REC frame
1663  */
1664 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1665 {
1666         int error = PTR_ERR(fp);
1667
1668         if (fc_fcp_lock_pkt(fsp))
1669                 goto out;
1670
1671         switch (error) {
1672         case -FC_EX_CLOSED:
1673                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange closed\n",
1674                            fsp, fsp->rport->port_id);
1675                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1676                 break;
1677
1678         default:
1679                 FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1680                            fsp, fsp->rport->port_id, error);
1681                 fsp->status_code = FC_CMD_PLOGO;
1682                 /* fall through */
1683
1684         case -FC_EX_TIMEOUT:
1685                 /*
1686                  * Assume REC or LS_ACC was lost.
1687                  * The exchange manager will have aborted REC, so retry.
1688                  */
1689                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange timeout retry %d/%d\n",
1690                            fsp, fsp->rport->port_id, fsp->recov_retry,
1691                            FC_MAX_RECOV_RETRY);
1692                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1693                         fc_fcp_rec(fsp);
1694                 else
1695                         fc_fcp_recovery(fsp, FC_ERROR);
1696                 break;
1697         }
1698         fc_fcp_unlock_pkt(fsp);
1699 out:
1700         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1701 }
1702
1703 /**
1704  * fc_fcp_recovery() - Handler for fcp_pkt recovery
1705  * @fsp: The FCP pkt that needs to be aborted
1706  */
1707 static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1708 {
1709         FC_FCP_DBG(fsp, "start recovery code %x\n", code);
1710         fsp->status_code = code;
1711         fsp->cdb_status = 0;
1712         fsp->io_status = 0;
1713         /*
1714          * if this fails then we let the scsi command timer fire and
1715          * scsi-ml escalate.
1716          */
1717         fc_fcp_send_abort(fsp);
1718 }
1719
1720 /**
1721  * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1722  * @fsp:   The FCP packet the SRR is to be sent on
1723  * @r_ctl: The R_CTL field for the SRR request
1724  * This is called after receiving status but insufficient data, or
1725  * when expecting status but the request has timed out.
1726  */
1727 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1728 {
1729         struct fc_lport *lport = fsp->lp;
1730         struct fc_rport *rport;
1731         struct fc_rport_libfc_priv *rpriv;
1732         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1733         struct fc_seq *seq;
1734         struct fcp_srr *srr;
1735         struct fc_frame *fp;
1736
1737         rport = fsp->rport;
1738         rpriv = rport->dd_data;
1739
1740         if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1741             rpriv->rp_state != RPORT_ST_READY)
1742                 goto retry;                     /* shouldn't happen */
1743         fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1744         if (!fp)
1745                 goto retry;
1746
1747         srr = fc_frame_payload_get(fp, sizeof(*srr));
1748         memset(srr, 0, sizeof(*srr));
1749         srr->srr_op = ELS_SRR;
1750         srr->srr_ox_id = htons(ep->oxid);
1751         srr->srr_rx_id = htons(ep->rxid);
1752         srr->srr_r_ctl = r_ctl;
1753         srr->srr_rel_off = htonl(offset);
1754
1755         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1756                        rpriv->local_port->port_id, FC_TYPE_FCP,
1757                        FC_FCTL_REQ, 0);
1758
1759         seq = fc_exch_seq_send(lport, fp, fc_fcp_srr_resp,
1760                                fc_fcp_pkt_destroy,
1761                                fsp, get_fsp_rec_tov(fsp));
1762         if (!seq)
1763                 goto retry;
1764
1765         fsp->recov_seq = seq;
1766         fsp->xfer_len = offset;
1767         fsp->xfer_contig_end = offset;
1768         fsp->state &= ~FC_SRB_RCV_STATUS;
1769         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1770         return;
1771 retry:
1772         fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1773 }
1774
1775 /**
1776  * fc_fcp_srr_resp() - Handler for SRR response
1777  * @seq: The sequence the SRR is on
1778  * @fp:  The SRR frame
1779  * @arg: The FCP packet the SRR is on
1780  */
1781 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1782 {
1783         struct fc_fcp_pkt *fsp = arg;
1784         struct fc_frame_header *fh;
1785
1786         if (IS_ERR(fp)) {
1787                 fc_fcp_srr_error(fsp, fp);
1788                 return;
1789         }
1790
1791         if (fc_fcp_lock_pkt(fsp))
1792                 goto out;
1793
1794         fh = fc_frame_header_get(fp);
1795         /*
1796          * BUG? fc_fcp_srr_error calls fc_exch_done which would release
1797          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1798          * then fc_exch_timeout would be sending an abort. The fc_exch_done
1799          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1800          * an abort response though.
1801          */
1802         if (fh->fh_type == FC_TYPE_BLS) {
1803                 fc_fcp_unlock_pkt(fsp);
1804                 return;
1805         }
1806
1807         switch (fc_frame_payload_op(fp)) {
1808         case ELS_LS_ACC:
1809                 fsp->recov_retry = 0;
1810                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1811                 break;
1812         case ELS_LS_RJT:
1813         default:
1814                 fc_fcp_recovery(fsp, FC_ERROR);
1815                 break;
1816         }
1817         fc_fcp_unlock_pkt(fsp);
1818 out:
1819         fc_exch_done(seq);
1820         fc_frame_free(fp);
1821 }
1822
1823 /**
1824  * fc_fcp_srr_error() - Handler for SRR errors
1825  * @fsp: The FCP packet that the SRR error is on
1826  * @fp:  The SRR frame
1827  */
1828 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1829 {
1830         if (fc_fcp_lock_pkt(fsp))
1831                 goto out;
1832         switch (PTR_ERR(fp)) {
1833         case -FC_EX_TIMEOUT:
1834                 FC_FCP_DBG(fsp, "SRR timeout, retries %d\n", fsp->recov_retry);
1835                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1836                         fc_fcp_rec(fsp);
1837                 else
1838                         fc_fcp_recovery(fsp, FC_TIMED_OUT);
1839                 break;
1840         case -FC_EX_CLOSED:                     /* e.g., link failure */
1841                 FC_FCP_DBG(fsp, "SRR error, exchange closed\n");
1842                 /* fall through */
1843         default:
1844                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1845                 break;
1846         }
1847         fc_fcp_unlock_pkt(fsp);
1848 out:
1849         fc_exch_done(fsp->recov_seq);
1850 }
1851
1852 /**
1853  * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1854  * @lport: The local port to be checked
1855  */
1856 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1857 {
1858         /* lock ? */
1859         return (lport->state == LPORT_ST_READY) &&
1860                 lport->link_up && !lport->qfull;
1861 }
1862
1863 /**
1864  * fc_queuecommand() - The queuecommand function of the SCSI template
1865  * @shost: The Scsi_Host that the command was issued to
1866  * @cmd:   The scsi_cmnd to be executed
1867  *
1868  * This is the i/o strategy routine, called by the SCSI layer.
1869  */
1870 int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1871 {
1872         struct fc_lport *lport = shost_priv(shost);
1873         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1874         struct fc_fcp_pkt *fsp;
1875         struct fc_rport_libfc_priv *rpriv;
1876         int rval;
1877         int rc = 0;
1878         struct fc_stats *stats;
1879
1880         rval = fc_remote_port_chkready(rport);
1881         if (rval) {
1882                 sc_cmd->result = rval;
1883                 sc_cmd->scsi_done(sc_cmd);
1884                 return 0;
1885         }
1886
1887         if (!*(struct fc_remote_port **)rport->dd_data) {
1888                 /*
1889                  * rport is transitioning from blocked/deleted to
1890                  * online
1891                  */
1892                 sc_cmd->result = DID_IMM_RETRY << 16;
1893                 sc_cmd->scsi_done(sc_cmd);
1894                 goto out;
1895         }
1896
1897         rpriv = rport->dd_data;
1898
1899         if (!fc_fcp_lport_queue_ready(lport)) {
1900                 if (lport->qfull) {
1901                         if (fc_fcp_can_queue_ramp_down(lport))
1902                                 shost_printk(KERN_ERR, lport->host,
1903                                              "libfc: queue full, "
1904                                              "reducing can_queue to %d.\n",
1905                                              lport->host->can_queue);
1906                 }
1907                 rc = SCSI_MLQUEUE_HOST_BUSY;
1908                 goto out;
1909         }
1910
1911         fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1912         if (fsp == NULL) {
1913                 rc = SCSI_MLQUEUE_HOST_BUSY;
1914                 goto out;
1915         }
1916
1917         /*
1918          * build the libfc request pkt
1919          */
1920         fsp->cmd = sc_cmd;      /* save the cmd */
1921         fsp->rport = rport;     /* set the remote port ptr */
1922
1923         /*
1924          * set up the transfer length
1925          */
1926         fsp->data_len = scsi_bufflen(sc_cmd);
1927         fsp->xfer_len = 0;
1928
1929         /*
1930          * setup the data direction
1931          */
1932         stats = per_cpu_ptr(lport->stats, get_cpu());
1933         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1934                 fsp->req_flags = FC_SRB_READ;
1935                 stats->InputRequests++;
1936                 stats->InputBytes += fsp->data_len;
1937         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1938                 fsp->req_flags = FC_SRB_WRITE;
1939                 stats->OutputRequests++;
1940                 stats->OutputBytes += fsp->data_len;
1941         } else {
1942                 fsp->req_flags = 0;
1943                 stats->ControlRequests++;
1944         }
1945         put_cpu();
1946
1947         /*
1948          * send it to the lower layer
1949          * if we get -1 return then put the request in the pending
1950          * queue.
1951          */
1952         rval = fc_fcp_pkt_send(lport, fsp);
1953         if (rval != 0) {
1954                 fsp->state = FC_SRB_FREE;
1955                 fc_fcp_pkt_release(fsp);
1956                 rc = SCSI_MLQUEUE_HOST_BUSY;
1957         }
1958 out:
1959         return rc;
1960 }
1961 EXPORT_SYMBOL(fc_queuecommand);
1962
1963 /**
1964  * fc_io_compl() - Handle responses for completed commands
1965  * @fsp: The FCP packet that is complete
1966  *
1967  * Translates fcp_pkt errors to a Linux SCSI errors.
1968  * The fcp packet lock must be held when calling.
1969  */
1970 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1971 {
1972         struct fc_fcp_internal *si;
1973         struct scsi_cmnd *sc_cmd;
1974         struct fc_lport *lport;
1975         unsigned long flags;
1976
1977         /* release outstanding ddp context */
1978         fc_fcp_ddp_done(fsp);
1979
1980         fsp->state |= FC_SRB_COMPL;
1981         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1982                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1983                 del_timer_sync(&fsp->timer);
1984                 spin_lock_bh(&fsp->scsi_pkt_lock);
1985         }
1986
1987         lport = fsp->lp;
1988         si = fc_get_scsi_internal(lport);
1989
1990         /*
1991          * if can_queue ramp down is done then try can_queue ramp up
1992          * since commands are completing now.
1993          */
1994         if (si->last_can_queue_ramp_down_time)
1995                 fc_fcp_can_queue_ramp_up(lport);
1996
1997         sc_cmd = fsp->cmd;
1998         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1999         switch (fsp->status_code) {
2000         case FC_COMPLETE:
2001                 if (fsp->cdb_status == 0) {
2002                         /*
2003                          * good I/O status
2004                          */
2005                         sc_cmd->result = DID_OK << 16;
2006                         if (fsp->scsi_resid)
2007                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2008                 } else {
2009                         /*
2010                          * transport level I/O was ok but scsi
2011                          * has non zero status
2012                          */
2013                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
2014                 }
2015                 break;
2016         case FC_ERROR:
2017                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2018                            "due to FC_ERROR\n");
2019                 sc_cmd->result = DID_ERROR << 16;
2020                 break;
2021         case FC_DATA_UNDRUN:
2022                 if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
2023                         /*
2024                          * scsi status is good but transport level
2025                          * underrun.
2026                          */
2027                         if (fsp->state & FC_SRB_RCV_STATUS) {
2028                                 sc_cmd->result = DID_OK << 16;
2029                         } else {
2030                                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
2031                                            " due to FC_DATA_UNDRUN (trans)\n");
2032                                 sc_cmd->result = DID_ERROR << 16;
2033                         }
2034                 } else {
2035                         /*
2036                          * scsi got underrun, this is an error
2037                          */
2038                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2039                                    "due to FC_DATA_UNDRUN (scsi)\n");
2040                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2041                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2042                 }
2043                 break;
2044         case FC_DATA_OVRRUN:
2045                 /*
2046                  * overrun is an error
2047                  */
2048                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2049                            "due to FC_DATA_OVRRUN\n");
2050                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2051                 break;
2052         case FC_CMD_ABORTED:
2053                 if (host_byte(sc_cmd->result) == DID_TIME_OUT)
2054                         FC_FCP_DBG(fsp, "Returning DID_TIME_OUT to scsi-ml "
2055                                    "due to FC_CMD_ABORTED\n");
2056                 else {
2057                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2058                                    "due to FC_CMD_ABORTED\n");
2059                         set_host_byte(sc_cmd, DID_ERROR);
2060                 }
2061                 sc_cmd->result |= fsp->io_status;
2062                 break;
2063         case FC_CMD_RESET:
2064                 FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
2065                            "due to FC_CMD_RESET\n");
2066                 sc_cmd->result = (DID_RESET << 16);
2067                 break;
2068         case FC_TRANS_RESET:
2069                 FC_FCP_DBG(fsp, "Returning DID_SOFT_ERROR to scsi-ml "
2070                            "due to FC_TRANS_RESET\n");
2071                 sc_cmd->result = (DID_SOFT_ERROR << 16);
2072                 break;
2073         case FC_HRD_ERROR:
2074                 FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
2075                            "due to FC_HRD_ERROR\n");
2076                 sc_cmd->result = (DID_NO_CONNECT << 16);
2077                 break;
2078         case FC_CRC_ERROR:
2079                 FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
2080                            "due to FC_CRC_ERROR\n");
2081                 sc_cmd->result = (DID_PARITY << 16);
2082                 break;
2083         case FC_TIMED_OUT:
2084                 FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
2085                            "due to FC_TIMED_OUT\n");
2086                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
2087                 break;
2088         default:
2089                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2090                            "due to unknown error\n");
2091                 sc_cmd->result = (DID_ERROR << 16);
2092                 break;
2093         }
2094
2095         if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2096                 sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2097
2098         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2099         list_del(&fsp->list);
2100         sc_cmd->SCp.ptr = NULL;
2101         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2102         sc_cmd->scsi_done(sc_cmd);
2103
2104         /* release ref from initial allocation in queue command */
2105         fc_fcp_pkt_release(fsp);
2106 }
2107
2108 /**
2109  * fc_eh_abort() - Abort a command
2110  * @sc_cmd: The SCSI command to abort
2111  *
2112  * From SCSI host template.
2113  * Send an ABTS to the target device and wait for the response.
2114  */
2115 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2116 {
2117         struct fc_fcp_pkt *fsp;
2118         struct fc_lport *lport;
2119         struct fc_fcp_internal *si;
2120         int rc = FAILED;
2121         unsigned long flags;
2122         int rval;
2123
2124         rval = fc_block_scsi_eh(sc_cmd);
2125         if (rval)
2126                 return rval;
2127
2128         lport = shost_priv(sc_cmd->device->host);
2129         if (lport->state != LPORT_ST_READY)
2130                 return rc;
2131         else if (!lport->link_up)
2132                 return rc;
2133
2134         si = fc_get_scsi_internal(lport);
2135         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2136         fsp = CMD_SP(sc_cmd);
2137         if (!fsp) {
2138                 /* command completed while scsi eh was setting up */
2139                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2140                 return SUCCESS;
2141         }
2142         /* grab a ref so the fsp and sc_cmd cannot be released from under us */
2143         fc_fcp_pkt_hold(fsp);
2144         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2145
2146         if (fc_fcp_lock_pkt(fsp)) {
2147                 /* completed while we were waiting for timer to be deleted */
2148                 rc = SUCCESS;
2149                 goto release_pkt;
2150         }
2151
2152         rc = fc_fcp_pkt_abort(fsp);
2153         fc_fcp_unlock_pkt(fsp);
2154
2155 release_pkt:
2156         fc_fcp_pkt_release(fsp);
2157         return rc;
2158 }
2159 EXPORT_SYMBOL(fc_eh_abort);
2160
2161 /**
2162  * fc_eh_device_reset() - Reset a single LUN
2163  * @sc_cmd: The SCSI command which identifies the device whose
2164  *          LUN is to be reset
2165  *
2166  * Set from SCSI host template.
2167  */
2168 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2169 {
2170         struct fc_lport *lport;
2171         struct fc_fcp_pkt *fsp;
2172         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2173         int rc = FAILED;
2174         int rval;
2175
2176         rval = fc_block_scsi_eh(sc_cmd);
2177         if (rval)
2178                 return rval;
2179
2180         lport = shost_priv(sc_cmd->device->host);
2181
2182         if (lport->state != LPORT_ST_READY)
2183                 return rc;
2184
2185         FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2186
2187         fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2188         if (fsp == NULL) {
2189                 printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2190                 goto out;
2191         }
2192
2193         /*
2194          * Build the libfc request pkt. Do not set the scsi cmnd, because
2195          * the sc passed in is not setup for execution like when sent
2196          * through the queuecommand callout.
2197          */
2198         fsp->rport = rport;     /* set the remote port ptr */
2199
2200         /*
2201          * flush outstanding commands
2202          */
2203         rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2204         fsp->state = FC_SRB_FREE;
2205         fc_fcp_pkt_release(fsp);
2206
2207 out:
2208         return rc;
2209 }
2210 EXPORT_SYMBOL(fc_eh_device_reset);
2211
2212 /**
2213  * fc_eh_host_reset() - Reset a Scsi_Host.
2214  * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2215  */
2216 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2217 {
2218         struct Scsi_Host *shost = sc_cmd->device->host;
2219         struct fc_lport *lport = shost_priv(shost);
2220         unsigned long wait_tmo;
2221
2222         FC_SCSI_DBG(lport, "Resetting host\n");
2223
2224         fc_lport_reset(lport);
2225         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2226         while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2227                                                                wait_tmo))
2228                 msleep(1000);
2229
2230         if (fc_fcp_lport_queue_ready(lport)) {
2231                 shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2232                              "on port (%6.6x)\n", lport->port_id);
2233                 return SUCCESS;
2234         } else {
2235                 shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2236                              "port (%6.6x) is not ready.\n",
2237                              lport->port_id);
2238                 return FAILED;
2239         }
2240 }
2241 EXPORT_SYMBOL(fc_eh_host_reset);
2242
2243 /**
2244  * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2245  * @sdev: The SCSI device that identifies the SCSI host
2246  *
2247  * Configures queue depth based on host's cmd_per_len. If not set
2248  * then we use the libfc default.
2249  */
2250 int fc_slave_alloc(struct scsi_device *sdev)
2251 {
2252         struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2253
2254         if (!rport || fc_remote_port_chkready(rport))
2255                 return -ENXIO;
2256
2257         scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2258         return 0;
2259 }
2260 EXPORT_SYMBOL(fc_slave_alloc);
2261
2262 /**
2263  * fc_fcp_destory() - Tear down the FCP layer for a given local port
2264  * @lport: The local port that no longer needs the FCP layer
2265  */
2266 void fc_fcp_destroy(struct fc_lport *lport)
2267 {
2268         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2269
2270         if (!list_empty(&si->scsi_pkt_queue))
2271                 printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2272                        "port (%6.6x)\n", lport->port_id);
2273
2274         mempool_destroy(si->scsi_pkt_pool);
2275         kfree(si);
2276         lport->scsi_priv = NULL;
2277 }
2278 EXPORT_SYMBOL(fc_fcp_destroy);
2279
2280 int fc_setup_fcp(void)
2281 {
2282         int rc = 0;
2283
2284         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2285                                             sizeof(struct fc_fcp_pkt),
2286                                             0, SLAB_HWCACHE_ALIGN, NULL);
2287         if (!scsi_pkt_cachep) {
2288                 printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2289                        "module load failed!");
2290                 rc = -ENOMEM;
2291         }
2292
2293         return rc;
2294 }
2295
2296 void fc_destroy_fcp(void)
2297 {
2298         if (scsi_pkt_cachep)
2299                 kmem_cache_destroy(scsi_pkt_cachep);
2300 }
2301
2302 /**
2303  * fc_fcp_init() - Initialize the FCP layer for a local port
2304  * @lport: The local port to initialize the exchange layer for
2305  */
2306 int fc_fcp_init(struct fc_lport *lport)
2307 {
2308         int rc;
2309         struct fc_fcp_internal *si;
2310
2311         if (!lport->tt.fcp_cmd_send)
2312                 lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2313
2314         if (!lport->tt.fcp_cleanup)
2315                 lport->tt.fcp_cleanup = fc_fcp_cleanup;
2316
2317         if (!lport->tt.fcp_abort_io)
2318                 lport->tt.fcp_abort_io = fc_fcp_abort_io;
2319
2320         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2321         if (!si)
2322                 return -ENOMEM;
2323         lport->scsi_priv = si;
2324         si->max_can_queue = lport->host->can_queue;
2325         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2326         spin_lock_init(&si->scsi_queue_lock);
2327
2328         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2329         if (!si->scsi_pkt_pool) {
2330                 rc = -ENOMEM;
2331                 goto free_internal;
2332         }
2333         return 0;
2334
2335 free_internal:
2336         kfree(si);
2337         return rc;
2338 }
2339 EXPORT_SYMBOL(fc_fcp_init);