drivers/scsi/libfc/fc_fcp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2007 Intel Corporation. All rights reserved.
   4  * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
   5  * Copyright(c) 2008 Mike Christie
   6  *
   7  * Maintained at www.Open-FCoE.org
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/delay.h>
  12 #include <linux/kernel.h>
  13 #include <linux/types.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/err.h>
  17 #include <linux/crc32.h>
  18 #include <linux/slab.h>
  19
  20 #include <scsi/scsi_tcq.h>
  21 #include <scsi/scsi.h>
  22 #include <scsi/scsi_host.h>
  23 #include <scsi/scsi_device.h>
  24 #include <scsi/scsi_cmnd.h>
  25
  26 #include <scsi/fc/fc_fc2.h>
  27
  28 #include <scsi/libfc.h>
  29 #include <scsi/fc_encode.h>
  30
  31 #include "fc_libfc.h"
  32
  33 static struct kmem_cache *scsi_pkt_cachep;
  34
  35 /* SRB state definitions */
  36 #define FC_SRB_FREE             0               /* cmd is free */
  37 #define FC_SRB_CMD_SENT         (1 << 0)        /* cmd has been sent */
  38 #define FC_SRB_RCV_STATUS       (1 << 1)        /* response has arrived */
  39 #define FC_SRB_ABORT_PENDING    (1 << 2)        /* cmd abort sent to device */
  40 #define FC_SRB_ABORTED          (1 << 3)        /* abort acknowledged */
  41 #define FC_SRB_DISCONTIG        (1 << 4)        /* non-sequential data recvd */
  42 #define FC_SRB_COMPL            (1 << 5)        /* fc_io_compl has been run */
  43 #define FC_SRB_FCP_PROCESSING_TMO (1 << 6)      /* timer function processing */
  44
  45 #define FC_SRB_READ             (1 << 1)
  46 #define FC_SRB_WRITE            (1 << 0)
  47
  48 /*
  49  * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
  50  */
  51 #define CMD_SP(Cmnd)                ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
  52 #define CMD_ENTRY_STATUS(Cmnd)      ((Cmnd)->SCp.have_data_in)
  53 #define CMD_COMPL_STATUS(Cmnd)      ((Cmnd)->SCp.this_residual)
  54 #define CMD_SCSI_STATUS(Cmnd)       ((Cmnd)->SCp.Status)
  55 #define CMD_RESID_LEN(Cmnd)         ((Cmnd)->SCp.buffers_residual)
  56
  57 /**
  58  * struct fc_fcp_internal - FCP layer internal data
  59  * @scsi_pkt_pool: Memory pool to draw FCP packets from
  60  * @scsi_queue_lock: Protects the scsi_pkt_queue
  61  * @scsi_pkt_queue: Current FCP packets
  62  * @last_can_queue_ramp_down_time: ramp down time
  63  * @last_can_queue_ramp_up_time: ramp up time
  64  * @max_can_queue: max can_queue size
  65  */
  66 struct fc_fcp_internal {
  67         mempool_t               *scsi_pkt_pool;
  68         spinlock_t              scsi_queue_lock;
  69         struct list_head        scsi_pkt_queue;
  70         unsigned long           last_can_queue_ramp_down_time;
  71         unsigned long           last_can_queue_ramp_up_time;
  72         int                     max_can_queue;
  73 };
  74
  75 #define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
  76
  77 /*
  78  * function prototypes
  79  * FC scsi I/O related functions
  80  */
  81 static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  82 static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  83 static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  84 static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  85 static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  86 static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
  87 static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
  88 static void fc_fcp_timeout(struct timer_list *);
  89 static void fc_fcp_rec(struct fc_fcp_pkt *);
  90 static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
  91 static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
  92 static void fc_io_compl(struct fc_fcp_pkt *);
  93
  94 static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
  95 static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
  96 static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
  97
  98 /*
  99  * command status codes
 100  */
 101 #define FC_COMPLETE             0
 102 #define FC_CMD_ABORTED          1
 103 #define FC_CMD_RESET            2
 104 #define FC_CMD_PLOGO            3
 105 #define FC_SNS_RCV              4
 106 #define FC_TRANS_ERR            5
 107 #define FC_DATA_OVRRUN          6
 108 #define FC_DATA_UNDRUN          7
 109 #define FC_ERROR                8
 110 #define FC_HRD_ERROR            9
 111 #define FC_CRC_ERROR            10
 112 #define FC_TIMED_OUT            11
 113 #define FC_TRANS_RESET          12
 114
 115 /*
 116  * Error recovery timeout values.
 117  */
 118 #define FC_SCSI_TM_TOV          (10 * HZ)
 119 #define FC_HOST_RESET_TIMEOUT   (30 * HZ)
 120 #define FC_CAN_QUEUE_PERIOD     (60 * HZ)
 121
 122 #define FC_MAX_ERROR_CNT        5
 123 #define FC_MAX_RECOV_RETRY      3
 124
 125 #define FC_FCP_DFLT_QUEUE_DEPTH 32
 126
 127 /**
 128  * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
 129  * @lport: The local port that the FCP packet is for
 130  * @gfp:   GFP flags for allocation
 131  *
 132  * Return value: fcp_pkt structure or null on allocation failure.
 133  * Context:      Can be called from process context, no lock is required.
 134  */
 135 static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
 136 {
 137         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 138         struct fc_fcp_pkt *fsp;
 139
 140         fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
 141         if (fsp) {
 142                 memset(fsp, 0, sizeof(*fsp));
 143                 fsp->lp = lport;
 144                 fsp->xfer_ddp = FC_XID_UNKNOWN;
 145                 refcount_set(&fsp->ref_cnt, 1);
 146                 timer_setup(&fsp->timer, NULL, 0);
 147                 INIT_LIST_HEAD(&fsp->list);
 148                 spin_lock_init(&fsp->scsi_pkt_lock);
 149         } else {
 150                 per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
 151                 put_cpu();
 152         }
 153         return fsp;
 154 }
 155
 156 /**
 157  * fc_fcp_pkt_release() - Release hold on a fcp_pkt
 158  * @fsp: The FCP packet to be released
 159  *
 160  * Context: Can be called from process or interrupt context,
 161  *          no lock is required.
 162  */
 163 static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
 164 {
 165         if (refcount_dec_and_test(&fsp->ref_cnt)) {
 166                 struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 167
 168                 mempool_free(fsp, si->scsi_pkt_pool);
 169         }
 170 }
 171
 172 /**
 173  * fc_fcp_pkt_hold() - Hold a fcp_pkt
 174  * @fsp: The FCP packet to be held
 175  */
 176 static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
 177 {
 178         refcount_inc(&fsp->ref_cnt);
 179 }
 180
 181 /**
 182  * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
 183  * @seq: The sequence that the FCP packet is on (required by destructor API)
 184  * @fsp: The FCP packet to be released
 185  *
 186  * This routine is called by a destructor callback in the fc_exch_seq_send()
 187  * routine of the libfc Transport Template. The 'struct fc_seq' is a required
 188  * argument even though it is not used by this routine.
 189  *
 190  * Context: No locking required.
 191  */
 192 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 193 {
 194         fc_fcp_pkt_release(fsp);
 195 }
 196
 197 /**
 198  * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
 199  * @fsp: The FCP packet to be locked and incremented
 200  *
 201  * We should only return error if we return a command to SCSI-ml before
 202  * getting a response. This can happen in cases where we send a abort, but
 203  * do not wait for the response and the abort and command can be passing
 204  * each other on the wire/network-layer.
 205  *
 206  * Note: this function locks the packet and gets a reference to allow
 207  * callers to call the completion function while the lock is held and
 208  * not have to worry about the packets refcount.
 209  *
 210  * TODO: Maybe we should just have callers grab/release the lock and
 211  * have a function that they call to verify the fsp and grab a ref if
 212  * needed.
 213  */
 214 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 215 {
 216         spin_lock_bh(&fsp->scsi_pkt_lock);
 217         if (fsp->state & FC_SRB_COMPL) {
 218                 spin_unlock_bh(&fsp->scsi_pkt_lock);
 219                 return -EPERM;
 220         }
 221
 222         fc_fcp_pkt_hold(fsp);
 223         return 0;
 224 }
 225
 226 /**
 227  * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
 228  *                       reference count
 229  * @fsp: The FCP packet to be unlocked and decremented
 230  */
 231 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 232 {
 233         spin_unlock_bh(&fsp->scsi_pkt_lock);
 234         fc_fcp_pkt_release(fsp);
 235 }
 236
 237 /**
 238  * fc_fcp_timer_set() - Start a timer for a fcp_pkt
 239  * @fsp:   The FCP packet to start a timer for
 240  * @delay: The timeout period in jiffies
 241  */
 242 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 243 {
 244         if (!(fsp->state & FC_SRB_COMPL)) {
 245                 mod_timer(&fsp->timer, jiffies + delay);
 246                 fsp->timer_delay = delay;
 247         }
 248 }
 249
 250 static void fc_fcp_abort_done(struct fc_fcp_pkt *fsp)
 251 {
 252         fsp->state |= FC_SRB_ABORTED;
 253         fsp->state &= ~FC_SRB_ABORT_PENDING;
 254
 255         if (fsp->wait_for_comp)
 256                 complete(&fsp->tm_done);
 257         else
 258                 fc_fcp_complete_locked(fsp);
 259 }
 260
 261 /**
 262  * fc_fcp_send_abort() - Send an abort for exchanges associated with a
 263  *                       fcp_pkt
 264  * @fsp: The FCP packet to abort exchanges on
 265  */
 266 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 267 {
 268         int rc;
 269
 270         if (!fsp->seq_ptr)
 271                 return -EINVAL;
 272
 273         per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
 274         put_cpu();
 275
 276         fsp->state |= FC_SRB_ABORT_PENDING;
 277         rc = fc_seq_exch_abort(fsp->seq_ptr, 0);
 278         /*
 279          * fc_seq_exch_abort() might return -ENXIO if
 280          * the sequence is already completed
 281          */
 282         if (rc == -ENXIO) {
 283                 fc_fcp_abort_done(fsp);
 284                 rc = 0;
 285         }
 286         return rc;
 287 }
 288
 289 /**
 290  * fc_fcp_retry_cmd() - Retry a fcp_pkt
 291  * @fsp: The FCP packet to be retried
 292  * @status_code: The FCP status code to set
 293  *
 294  * Sets the status code to be FC_ERROR and then calls
 295  * fc_fcp_complete_locked() which in turn calls fc_io_compl().
 296  * fc_io_compl() will notify the SCSI-ml that the I/O is done.
 297  * The SCSI-ml will retry the command.
 298  */
 299 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp, int status_code)
 300 {
 301         if (fsp->seq_ptr) {
 302                 fc_exch_done(fsp->seq_ptr);
 303                 fsp->seq_ptr = NULL;
 304         }
 305
 306         fsp->state &= ~FC_SRB_ABORT_PENDING;
 307         fsp->io_status = 0;
 308         fsp->status_code = status_code;
 309         fc_fcp_complete_locked(fsp);
 310 }
 311
 312 /**
 313  * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
 314  * @fsp: The FCP packet that will manage the DDP frames
 315  * @xid: The XID that will be used for the DDP exchange
 316  */
 317 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
 318 {
 319         struct fc_lport *lport;
 320
 321         lport = fsp->lp;
 322         if ((fsp->req_flags & FC_SRB_READ) &&
 323             (lport->lro_enabled) && (lport->tt.ddp_setup)) {
 324                 if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
 325                                         scsi_sg_count(fsp->cmd)))
 326                         fsp->xfer_ddp = xid;
 327         }
 328 }
 329
 330 /**
 331  * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
 332  *                     DDP related resources for a fcp_pkt
 333  * @fsp: The FCP packet that DDP had been used on
 334  */
 335 void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
 336 {
 337         struct fc_lport *lport;
 338
 339         if (!fsp)
 340                 return;
 341
 342         if (fsp->xfer_ddp == FC_XID_UNKNOWN)
 343                 return;
 344
 345         lport = fsp->lp;
 346         if (lport->tt.ddp_done) {
 347                 fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
 348                 fsp->xfer_ddp = FC_XID_UNKNOWN;
 349         }
 350 }
 351
 352 /**
 353  * fc_fcp_can_queue_ramp_up() - increases can_queue
 354  * @lport: lport to ramp up can_queue
 355  */
 356 static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
 357 {
 358         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 359         unsigned long flags;
 360         int can_queue;
 361
 362         spin_lock_irqsave(lport->host->host_lock, flags);
 363
 364         if (si->last_can_queue_ramp_up_time &&
 365             (time_before(jiffies, si->last_can_queue_ramp_up_time +
 366                          FC_CAN_QUEUE_PERIOD)))
 367                 goto unlock;
 368
 369         if (time_before(jiffies, si->last_can_queue_ramp_down_time +
 370                         FC_CAN_QUEUE_PERIOD))
 371                 goto unlock;
 372
 373         si->last_can_queue_ramp_up_time = jiffies;
 374
 375         can_queue = lport->host->can_queue << 1;
 376         if (can_queue >= si->max_can_queue) {
 377                 can_queue = si->max_can_queue;
 378                 si->last_can_queue_ramp_down_time = 0;
 379         }
 380         lport->host->can_queue = can_queue;
 381         shost_printk(KERN_ERR, lport->host, "libfc: increased "
 382                      "can_queue to %d.\n", can_queue);
 383
 384 unlock:
 385         spin_unlock_irqrestore(lport->host->host_lock, flags);
 386 }
 387
 388 /**
 389  * fc_fcp_can_queue_ramp_down() - reduces can_queue
 390  * @lport: lport to reduce can_queue
 391  *
 392  * If we are getting memory allocation failures, then we may
 393  * be trying to execute too many commands. We let the running
 394  * commands complete or timeout, then try again with a reduced
 395  * can_queue. Eventually we will hit the point where we run
 396  * on all reserved structs.
 397  */
 398 static bool fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
 399 {
 400         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 401         unsigned long flags;
 402         int can_queue;
 403         bool changed = false;
 404
 405         spin_lock_irqsave(lport->host->host_lock, flags);
 406
 407         if (si->last_can_queue_ramp_down_time &&
 408             (time_before(jiffies, si->last_can_queue_ramp_down_time +
 409                          FC_CAN_QUEUE_PERIOD)))
 410                 goto unlock;
 411
 412         si->last_can_queue_ramp_down_time = jiffies;
 413
 414         can_queue = lport->host->can_queue;
 415         can_queue >>= 1;
 416         if (!can_queue)
 417                 can_queue = 1;
 418         lport->host->can_queue = can_queue;
 419         changed = true;
 420
 421 unlock:
 422         spin_unlock_irqrestore(lport->host->host_lock, flags);
 423         return changed;
 424 }
 425
 426 /*
 427  * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
 428  * @lport:      fc lport struct
 429  * @len:        payload length
 430  *
 431  * Allocates fc_frame structure and buffer but if fails to allocate
 432  * then reduce can_queue.
 433  */
 434 static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
 435                                                   size_t len)
 436 {
 437         struct fc_frame *fp;
 438
 439         fp = fc_frame_alloc(lport, len);
 440         if (likely(fp))
 441                 return fp;
 442
 443         per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
 444         put_cpu();
 445         /* error case */
 446         fc_fcp_can_queue_ramp_down(lport);
 447         shost_printk(KERN_ERR, lport->host,
 448                      "libfc: Could not allocate frame, "
 449                      "reducing can_queue to %d.\n", lport->host->can_queue);
 450         return NULL;
 451 }
 452
 453 /**
 454  * get_fsp_rec_tov() - Helper function to get REC_TOV
 455  * @fsp: the FCP packet
 456  *
 457  * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
 458  */
 459 static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
 460 {
 461         struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
 462         unsigned int e_d_tov = FC_DEF_E_D_TOV;
 463
 464         if (rpriv && rpriv->e_d_tov > e_d_tov)
 465                 e_d_tov = rpriv->e_d_tov;
 466         return msecs_to_jiffies(e_d_tov) + HZ;
 467 }
 468
 469 /**
 470  * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
 471  * @fsp: The FCP packet the data is on
 472  * @fp:  The data frame
 473  */
 474 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 475 {
 476         struct scsi_cmnd *sc = fsp->cmd;
 477         struct fc_lport *lport = fsp->lp;
 478         struct fc_stats *stats;
 479         struct fc_frame_header *fh;
 480         size_t start_offset;
 481         size_t offset;
 482         u32 crc;
 483         u32 copy_len = 0;
 484         size_t len;
 485         void *buf;
 486         struct scatterlist *sg;
 487         u32 nents;
 488         u8 host_bcode = FC_COMPLETE;
 489
 490         fh = fc_frame_header_get(fp);
 491         offset = ntohl(fh->fh_parm_offset);
 492         start_offset = offset;
 493         len = fr_len(fp) - sizeof(*fh);
 494         buf = fc_frame_payload_get(fp, 0);
 495
 496         /*
 497          * if this I/O is ddped then clear it and initiate recovery since data
 498          * frames are expected to be placed directly in that case.
 499          *
 500          * Indicate error to scsi-ml because something went wrong with the
 501          * ddp handling to get us here.
 502          */
 503         if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
 504                 fc_fcp_ddp_done(fsp);
 505                 FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
 506                 host_bcode = FC_ERROR;
 507                 goto err;
 508         }
 509         if (offset + len > fsp->data_len) {
 510                 /* this should never happen */
 511                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 512                     fc_frame_crc_check(fp))
 513                         goto crc_err;
 514                 FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
 515                            "data_len %x\n", len, offset, fsp->data_len);
 516
 517                 /* Data is corrupted indicate scsi-ml should retry */
 518                 host_bcode = FC_DATA_OVRRUN;
 519                 goto err;
 520         }
 521         if (offset != fsp->xfer_len)
 522                 fsp->state |= FC_SRB_DISCONTIG;
 523
 524         sg = scsi_sglist(sc);
 525         nents = scsi_sg_count(sc);
 526
 527         if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
 528                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 529                                                     &offset, NULL);
 530         } else {
 531                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 532                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 533                                                     &offset, &crc);
 534                 buf = fc_frame_payload_get(fp, 0);
 535                 if (len % 4)
 536                         crc = crc32(crc, buf + len, 4 - (len % 4));
 537
 538                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 539 crc_err:
 540                         stats = per_cpu_ptr(lport->stats, get_cpu());
 541                         stats->ErrorFrames++;
 542                         /* per cpu count, not total count, but OK for limit */
 543                         if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
 544                                 printk(KERN_WARNING "libfc: CRC error on data "
 545                                        "frame for port (%6.6x)\n",
 546                                        lport->port_id);
 547                         put_cpu();
 548                         /*
 549                          * Assume the frame is total garbage.
 550                          * We may have copied it over the good part
 551                          * of the buffer.
 552                          * If so, we need to retry the entire operation.
 553                          * Otherwise, ignore it.
 554                          */
 555                         if (fsp->state & FC_SRB_DISCONTIG) {
 556                                 host_bcode = FC_CRC_ERROR;
 557                                 goto err;
 558                         }
 559                         return;
 560                 }
 561         }
 562
 563         if (fsp->xfer_contig_end == start_offset)
 564                 fsp->xfer_contig_end += copy_len;
 565         fsp->xfer_len += copy_len;
 566
 567         /*
 568          * In the very rare event that this data arrived after the response
 569          * and completes the transfer, call the completion handler.
 570          */
 571         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 572             fsp->xfer_len == fsp->data_len - fsp->scsi_resid) {
 573                 FC_FCP_DBG( fsp, "complete out-of-order sequence\n" );
 574                 fc_fcp_complete_locked(fsp);
 575         }
 576         return;
 577 err:
 578         fc_fcp_recovery(fsp, host_bcode);
 579 }
 580
 581 /**
 582  * fc_fcp_send_data() - Send SCSI data to a target
 583  * @fsp:      The FCP packet the data is on
 584  * @seq:      The sequence the data is to be sent on
 585  * @offset:   The starting offset for this data request
 586  * @seq_blen: The burst length for this data request
 587  *
 588  * Called after receiving a Transfer Ready data descriptor.
 589  * If the LLD is capable of sequence offload then send down the
 590  * seq_blen amount of data in single frame, otherwise send
 591  * multiple frames of the maximum frame payload supported by
 592  * the target port.
 593  */
 594 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 595                             size_t offset, size_t seq_blen)
 596 {
 597         struct fc_exch *ep;
 598         struct scsi_cmnd *sc;
 599         struct scatterlist *sg;
 600         struct fc_frame *fp = NULL;
 601         struct fc_lport *lport = fsp->lp;
 602         struct page *page;
 603         size_t remaining;
 604         size_t t_blen;
 605         size_t tlen;
 606         size_t sg_bytes;
 607         size_t frame_offset, fh_parm_offset;
 608         size_t off;
 609         int error;
 610         void *data = NULL;
 611         void *page_addr;
 612         int using_sg = lport->sg_supp;
 613         u32 f_ctl;
 614
 615         WARN_ON(seq_blen <= 0);
 616         if (unlikely(offset + seq_blen > fsp->data_len)) {
 617                 /* this should never happen */
 618                 FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
 619                            "offset %zx\n", seq_blen, offset);
 620                 fc_fcp_send_abort(fsp);
 621                 return 0;
 622         } else if (offset != fsp->xfer_len) {
 623                 /* Out of Order Data Request - no problem, but unexpected. */
 624                 FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
 625                            "seq_blen %zx offset %zx\n", seq_blen, offset);
 626         }
 627
 628         /*
 629          * if LLD is capable of seq_offload then set transport
 630          * burst length (t_blen) to seq_blen, otherwise set t_blen
 631          * to max FC frame payload previously set in fsp->max_payload.
 632          */
 633         t_blen = fsp->max_payload;
 634         if (lport->seq_offload) {
 635                 t_blen = min(seq_blen, (size_t)lport->lso_max);
 636                 FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
 637                            fsp, seq_blen, lport->lso_max, t_blen);
 638         }
 639
 640         if (t_blen > 512)
 641                 t_blen &= ~(512 - 1);   /* round down to block size */
 642         sc = fsp->cmd;
 643
 644         remaining = seq_blen;
 645         fh_parm_offset = frame_offset = offset;
 646         tlen = 0;
 647         seq = fc_seq_start_next(seq);
 648         f_ctl = FC_FC_REL_OFF;
 649         WARN_ON(!seq);
 650
 651         sg = scsi_sglist(sc);
 652
 653         while (remaining > 0 && sg) {
 654                 if (offset >= sg->length) {
 655                         offset -= sg->length;
 656                         sg = sg_next(sg);
 657                         continue;
 658                 }
 659                 if (!fp) {
 660                         tlen = min(t_blen, remaining);
 661
 662                         /*
 663                          * TODO.  Temporary workaround.  fc_seq_send() can't
 664                          * handle odd lengths in non-linear skbs.
 665                          * This will be the final fragment only.
 666                          */
 667                         if (tlen % 4)
 668                                 using_sg = 0;
 669                         fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
 670                         if (!fp)
 671                                 return -ENOMEM;
 672
 673                         data = fc_frame_header_get(fp) + 1;
 674                         fh_parm_offset = frame_offset;
 675                         fr_max_payload(fp) = fsp->max_payload;
 676                 }
 677
 678                 off = offset + sg->offset;
 679                 sg_bytes = min(tlen, sg->length - offset);
 680                 sg_bytes = min(sg_bytes,
 681                                (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
 682                 page = sg_page(sg) + (off >> PAGE_SHIFT);
 683                 if (using_sg) {
 684                         get_page(page);
 685                         skb_fill_page_desc(fp_skb(fp),
 686                                            skb_shinfo(fp_skb(fp))->nr_frags,
 687                                            page, off & ~PAGE_MASK, sg_bytes);
 688                         fp_skb(fp)->data_len += sg_bytes;
 689                         fr_len(fp) += sg_bytes;
 690                         fp_skb(fp)->truesize += PAGE_SIZE;
 691                 } else {
 692                         /*
 693                          * The scatterlist item may be bigger than PAGE_SIZE,
 694                          * but we must not cross pages inside the kmap.
 695                          */
 696                         page_addr = kmap_atomic(page);
 697                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 698                                sg_bytes);
 699                         kunmap_atomic(page_addr);
 700                         data += sg_bytes;
 701                 }
 702                 offset += sg_bytes;
 703                 frame_offset += sg_bytes;
 704                 tlen -= sg_bytes;
 705                 remaining -= sg_bytes;
 706
 707                 if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
 708                     (tlen))
 709                         continue;
 710
 711                 /*
 712                  * Send sequence with transfer sequence initiative in case
 713                  * this is last FCP frame of the sequence.
 714                  */
 715                 if (remaining == 0)
 716                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 717
 718                 ep = fc_seq_exch(seq);
 719                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 720                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
 721
 722                 /*
 723                  * send fragment using for a sequence.
 724                  */
 725                 error = fc_seq_send(lport, seq, fp);
 726                 if (error) {
 727                         WARN_ON(1);             /* send error should be rare */
 728                         return error;
 729                 }
 730                 fp = NULL;
 731         }
 732         fsp->xfer_len += seq_blen;      /* premature count? */
 733         return 0;
 734 }
 735
 736 /**
 737  * fc_fcp_abts_resp() - Receive an ABTS response
 738  * @fsp: The FCP packet that is being aborted
 739  * @fp:  The response frame
 740  */
 741 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 742 {
 743         int ba_done = 1;
 744         struct fc_ba_rjt *brp;
 745         struct fc_frame_header *fh;
 746
 747         fh = fc_frame_header_get(fp);
 748         switch (fh->fh_r_ctl) {
 749         case FC_RCTL_BA_ACC:
 750                 break;
 751         case FC_RCTL_BA_RJT:
 752                 brp = fc_frame_payload_get(fp, sizeof(*brp));
 753                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 754                         break;
 755                 fallthrough;
 756         default:
 757                 /*
 758                  * we will let the command timeout
 759                  * and scsi-ml recover in this case,
 760                  * therefore cleared the ba_done flag.
 761                  */
 762                 ba_done = 0;
 763         }
 764
 765         if (ba_done)
 766                 fc_fcp_abort_done(fsp);
 767 }
 768
 769 /**
 770  * fc_fcp_recv() - Receive an FCP frame
 771  * @seq: The sequence the frame is on
 772  * @fp:  The received frame
 773  * @arg: The related FCP packet
 774  *
 775  * Context: Called from Soft IRQ context. Can not be called
 776  *          holding the FCP packet list lock.
 777  */
 778 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 779 {
 780         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 781         struct fc_lport *lport = fsp->lp;
 782         struct fc_frame_header *fh;
 783         struct fcp_txrdy *dd;
 784         u8 r_ctl;
 785         int rc = 0;
 786
 787         if (IS_ERR(fp)) {
 788                 fc_fcp_error(fsp, fp);
 789                 return;
 790         }
 791
 792         fh = fc_frame_header_get(fp);
 793         r_ctl = fh->fh_r_ctl;
 794
 795         if (lport->state != LPORT_ST_READY) {
 796                 FC_FCP_DBG(fsp, "lport state %d, ignoring r_ctl %x\n",
 797                            lport->state, r_ctl);
 798                 goto out;
 799         }
 800         if (fc_fcp_lock_pkt(fsp))
 801                 goto out;
 802
 803         if (fh->fh_type == FC_TYPE_BLS) {
 804                 fc_fcp_abts_resp(fsp, fp);
 805                 goto unlock;
 806         }
 807
 808         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING)) {
 809                 FC_FCP_DBG(fsp, "command aborted, ignoring r_ctl %x\n", r_ctl);
 810                 goto unlock;
 811         }
 812
 813         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 814                 /*
 815                  * received XFER RDY from the target
 816                  * need to send data to the target
 817                  */
 818                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 819                 dd = fc_frame_payload_get(fp, sizeof(*dd));
 820                 WARN_ON(!dd);
 821
 822                 rc = fc_fcp_send_data(fsp, seq,
 823                                       (size_t) ntohl(dd->ft_data_ro),
 824                                       (size_t) ntohl(dd->ft_burst_len));
 825                 if (!rc)
 826                         seq->rec_data = fsp->xfer_len;
 827         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 828                 /*
 829                  * received a DATA frame
 830                  * next we will copy the data to the system buffer
 831                  */
 832                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
 833                 fc_fcp_recv_data(fsp, fp);
 834                 seq->rec_data = fsp->xfer_contig_end;
 835         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 836                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 837
 838                 fc_fcp_resp(fsp, fp);
 839         } else {
 840                 FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
 841         }
 842 unlock:
 843         fc_fcp_unlock_pkt(fsp);
 844 out:
 845         fc_frame_free(fp);
 846 }
 847
 848 /**
 849  * fc_fcp_resp() - Handler for FCP responses
 850  * @fsp: The FCP packet the response is for
 851  * @fp:  The response frame
 852  */
 853 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 854 {
 855         struct fc_frame_header *fh;
 856         struct fcp_resp *fc_rp;
 857         struct fcp_resp_ext *rp_ex;
 858         struct fcp_resp_rsp_info *fc_rp_info;
 859         u32 plen;
 860         u32 expected_len;
 861         u32 respl = 0;
 862         u32 snsl = 0;
 863         u8 flags = 0;
 864
 865         plen = fr_len(fp);
 866         fh = (struct fc_frame_header *)fr_hdr(fp);
 867         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 868                 goto len_err;
 869         plen -= sizeof(*fh);
 870         fc_rp = (struct fcp_resp *)(fh + 1);
 871         fsp->cdb_status = fc_rp->fr_status;
 872         flags = fc_rp->fr_flags;
 873         fsp->scsi_comp_flags = flags;
 874         expected_len = fsp->data_len;
 875
 876         /* if ddp, update xfer len */
 877         fc_fcp_ddp_done(fsp);
 878
 879         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 880                 rp_ex = (void *)(fc_rp + 1);
 881                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 882                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 883                                 goto len_err;
 884                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 885                         if (flags & FCP_RSP_LEN_VAL) {
 886                                 respl = ntohl(rp_ex->fr_rsp_len);
 887                                 if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
 888                                     (respl != FCP_RESP_RSP_INFO_LEN8))
 889                                         goto len_err;
 890                                 if (fsp->wait_for_comp) {
 891                                         /* Abuse cdb_status for rsp code */
 892                                         fsp->cdb_status = fc_rp_info->rsp_code;
 893                                         complete(&fsp->tm_done);
 894                                         /*
 895                                          * tmfs will not have any scsi cmd so
 896                                          * exit here
 897                                          */
 898                                         return;
 899                                 }
 900                         }
 901                         if (flags & FCP_SNS_LEN_VAL) {
 902                                 snsl = ntohl(rp_ex->fr_sns_len);
 903                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
 904                                         snsl = SCSI_SENSE_BUFFERSIZE;
 905                                 memcpy(fsp->cmd->sense_buffer,
 906                                        (char *)fc_rp_info + respl, snsl);
 907                         }
 908                 }
 909                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 910                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 911                                 goto len_err;
 912                         if (flags & FCP_RESID_UNDER) {
 913                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 914                                 /*
 915                                  * The cmnd->underflow is the minimum number of
 916                                  * bytes that must be transferred for this
 917                                  * command.  Provided a sense condition is not
 918                                  * present, make sure the actual amount
 919                                  * transferred is at least the underflow value
 920                                  * or fail.
 921                                  */
 922                                 if (!(flags & FCP_SNS_LEN_VAL) &&
 923                                     (fc_rp->fr_status == 0) &&
 924                                     (scsi_bufflen(fsp->cmd) -
 925                                      fsp->scsi_resid) < fsp->cmd->underflow)
 926                                         goto err;
 927                                 expected_len -= fsp->scsi_resid;
 928                         } else {
 929                                 fsp->status_code = FC_ERROR;
 930                         }
 931                 }
 932         }
 933         fsp->state |= FC_SRB_RCV_STATUS;
 934
 935         /*
 936          * Check for missing or extra data frames.
 937          */
 938         if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
 939                      fsp->xfer_len != expected_len)) {
 940                 if (fsp->xfer_len < expected_len) {
 941                         /*
 942                          * Some data may be queued locally,
 943                          * Wait a at least one jiffy to see if it is delivered.
 944                          * If this expires without data, we may do SRR.
 945                          */
 946                         if (fsp->lp->qfull) {
 947                                 FC_FCP_DBG(fsp, "tgt %6.6x queue busy retry\n",
 948                                            fsp->rport->port_id);
 949                                 return;
 950                         }
 951                         FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx data underrun "
 952                                    "len %x, data len %x\n",
 953                                    fsp->rport->port_id,
 954                                    fsp->xfer_len, expected_len, fsp->data_len);
 955                         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
 956                         return;
 957                 }
 958                 fsp->status_code = FC_DATA_OVRRUN;
 959                 FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
 960                            "len %x, data len %x\n",
 961                            fsp->rport->port_id,
 962                            fsp->xfer_len, expected_len, fsp->data_len);
 963         }
 964         fc_fcp_complete_locked(fsp);
 965         return;
 966
 967 len_err:
 968         FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
 969                    "snsl %u\n", flags, fr_len(fp), respl, snsl);
 970 err:
 971         fsp->status_code = FC_ERROR;
 972         fc_fcp_complete_locked(fsp);
 973 }
 974
 975 /**
 976  * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
 977  *                            fcp_pkt lock held
 978  * @fsp: The FCP packet to be completed
 979  *
 980  * This function may sleep if a timer is pending. The packet lock must be
 981  * held, and the host lock must not be held.
 982  */
 983 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 984 {
 985         struct fc_lport *lport = fsp->lp;
 986         struct fc_seq *seq;
 987         struct fc_exch *ep;
 988         u32 f_ctl;
 989
 990         if (fsp->state & FC_SRB_ABORT_PENDING)
 991                 return;
 992
 993         if (fsp->state & FC_SRB_ABORTED) {
 994                 if (!fsp->status_code)
 995                         fsp->status_code = FC_CMD_ABORTED;
 996         } else {
 997                 /*
 998                  * Test for transport underrun, independent of response
 999                  * underrun status.
1000                  */
1001                 if (fsp->cdb_status == SAM_STAT_GOOD &&
1002                     fsp->xfer_len < fsp->data_len && !fsp->io_status &&
1003                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
1004                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
1005                         FC_FCP_DBG(fsp, "data underrun, xfer %zx data %x\n",
1006                                     fsp->xfer_len, fsp->data_len);
1007                         fsp->status_code = FC_DATA_UNDRUN;
1008                 }
1009         }
1010
1011         seq = fsp->seq_ptr;
1012         if (seq) {
1013                 fsp->seq_ptr = NULL;
1014                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
1015                         struct fc_frame *conf_frame;
1016                         struct fc_seq *csp;
1017
1018                         csp = fc_seq_start_next(seq);
1019                         conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
1020                         if (conf_frame) {
1021                                 f_ctl = FC_FC_SEQ_INIT;
1022                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1023                                 ep = fc_seq_exch(seq);
1024                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
1025                                                ep->did, ep->sid,
1026                                                FC_TYPE_FCP, f_ctl, 0);
1027                                 fc_seq_send(lport, csp, conf_frame);
1028                         }
1029                 }
1030                 fc_exch_done(seq);
1031         }
1032         /*
1033          * Some resets driven by SCSI are not I/Os and do not have
1034          * SCSI commands associated with the requests. We should not
1035          * call I/O completion if we do not have a SCSI command.
1036          */
1037         if (fsp->cmd)
1038                 fc_io_compl(fsp);
1039 }
1040
1041 /**
1042  * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
1043  * @fsp:   The FCP packet whose exchanges should be canceled
1044  * @error: The reason for the cancellation
1045  */
1046 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1047 {
1048         if (fsp->seq_ptr) {
1049                 fc_exch_done(fsp->seq_ptr);
1050                 fsp->seq_ptr = NULL;
1051         }
1052         fsp->status_code = error;
1053 }
1054
1055 /**
1056  * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1057  * @lport: The local port whose exchanges should be canceled
1058  * @id:    The target's ID
1059  * @lun:   The LUN
1060  * @error: The reason for cancellation
1061  *
1062  * If lun or id is -1, they are ignored.
1063  */
1064 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1065                                     unsigned int lun, int error)
1066 {
1067         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1068         struct fc_fcp_pkt *fsp;
1069         struct scsi_cmnd *sc_cmd;
1070         unsigned long flags;
1071
1072         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1073 restart:
1074         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1075                 sc_cmd = fsp->cmd;
1076                 if (id != -1 && scmd_id(sc_cmd) != id)
1077                         continue;
1078
1079                 if (lun != -1 && sc_cmd->device->lun != lun)
1080                         continue;
1081
1082                 fc_fcp_pkt_hold(fsp);
1083                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1084
1085                 spin_lock_bh(&fsp->scsi_pkt_lock);
1086                 if (!(fsp->state & FC_SRB_COMPL)) {
1087                         fsp->state |= FC_SRB_COMPL;
1088                         /*
1089                          * TODO: dropping scsi_pkt_lock and then reacquiring
1090                          * again around fc_fcp_cleanup_cmd() is required,
1091                          * since fc_fcp_cleanup_cmd() calls into
1092                          * fc_seq_set_resp() and that func preempts cpu using
1093                          * schedule. May be schedule and related code should be
1094                          * removed instead of unlocking here to avoid scheduling
1095                          * while atomic bug.
1096                          */
1097                         spin_unlock_bh(&fsp->scsi_pkt_lock);
1098
1099                         fc_fcp_cleanup_cmd(fsp, error);
1100
1101                         spin_lock_bh(&fsp->scsi_pkt_lock);
1102                         fc_io_compl(fsp);
1103                 }
1104                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1105
1106                 fc_fcp_pkt_release(fsp);
1107                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1108                 /*
1109                  * while we dropped the lock multiple pkts could
1110                  * have been released, so we have to start over.
1111                  */
1112                 goto restart;
1113         }
1114         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1115 }
1116
1117 /**
1118  * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1119  * @lport: The local port whose exchanges are to be aborted
1120  */
1121 static void fc_fcp_abort_io(struct fc_lport *lport)
1122 {
1123         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1124 }
1125
1126 /**
1127  * fc_fcp_pkt_send() - Send a fcp_pkt
1128  * @lport: The local port to send the FCP packet on
1129  * @fsp:   The FCP packet to send
1130  *
1131  * Return:  Zero for success and -1 for failure
1132  * Locks:   Called without locks held
1133  */
1134 static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1135 {
1136         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1137         unsigned long flags;
1138         int rc;
1139
1140         fsp->cmd->SCp.ptr = (char *)fsp;
1141         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1142         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1143
1144         int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1145         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1146
1147         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1148         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1149         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1150         rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1151         if (unlikely(rc)) {
1152                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1153                 fsp->cmd->SCp.ptr = NULL;
1154                 list_del(&fsp->list);
1155                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1156         }
1157
1158         return rc;
1159 }
1160
1161 /**
1162  * fc_fcp_cmd_send() - Send a FCP command
1163  * @lport: The local port to send the command on
1164  * @fsp:   The FCP packet the command is on
1165  * @resp:  The handler for the response
1166  */
1167 static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1168                            void (*resp)(struct fc_seq *,
1169                                         struct fc_frame *fp,
1170                                         void *arg))
1171 {
1172         struct fc_frame *fp;
1173         struct fc_seq *seq;
1174         struct fc_rport *rport;
1175         struct fc_rport_libfc_priv *rpriv;
1176         const size_t len = sizeof(fsp->cdb_cmd);
1177         int rc = 0;
1178
1179         if (fc_fcp_lock_pkt(fsp))
1180                 return 0;
1181
1182         fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1183         if (!fp) {
1184                 rc = -1;
1185                 goto unlock;
1186         }
1187
1188         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1189         fr_fsp(fp) = fsp;
1190         rport = fsp->rport;
1191         fsp->max_payload = rport->maxframe_size;
1192         rpriv = rport->dd_data;
1193
1194         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1195                        rpriv->local_port->port_id, FC_TYPE_FCP,
1196                        FC_FCTL_REQ, 0);
1197
1198         seq = fc_exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1199         if (!seq) {
1200                 rc = -1;
1201                 goto unlock;
1202         }
1203         fsp->seq_ptr = seq;
1204         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1205
1206         fsp->timer.function = fc_fcp_timeout;
1207         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1208                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1209
1210 unlock:
1211         fc_fcp_unlock_pkt(fsp);
1212         return rc;
1213 }
1214
1215 /**
1216  * fc_fcp_error() - Handler for FCP layer errors
1217  * @fsp: The FCP packet the error is on
1218  * @fp:  The frame that has errored
1219  */
1220 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1221 {
1222         int error = PTR_ERR(fp);
1223
1224         if (fc_fcp_lock_pkt(fsp))
1225                 return;
1226
1227         if (error == -FC_EX_CLOSED) {
1228                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1229                 goto unlock;
1230         }
1231
1232         /*
1233          * clear abort pending, because the lower layer
1234          * decided to force completion.
1235          */
1236         fsp->state &= ~FC_SRB_ABORT_PENDING;
1237         fsp->status_code = FC_CMD_PLOGO;
1238         fc_fcp_complete_locked(fsp);
1239 unlock:
1240         fc_fcp_unlock_pkt(fsp);
1241 }
1242
1243 /**
1244  * fc_fcp_pkt_abort() - Abort a fcp_pkt
1245  * @fsp:   The FCP packet to abort on
1246  *
1247  * Called to send an abort and then wait for abort completion
1248  */
1249 static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1250 {
1251         int rc = FAILED;
1252         unsigned long ticks_left;
1253
1254         FC_FCP_DBG(fsp, "pkt abort state %x\n", fsp->state);
1255         if (fc_fcp_send_abort(fsp)) {
1256                 FC_FCP_DBG(fsp, "failed to send abort\n");
1257                 return FAILED;
1258         }
1259
1260         if (fsp->state & FC_SRB_ABORTED) {
1261                 FC_FCP_DBG(fsp, "target abort cmd  completed\n");
1262                 return SUCCESS;
1263         }
1264
1265         init_completion(&fsp->tm_done);
1266         fsp->wait_for_comp = 1;
1267
1268         spin_unlock_bh(&fsp->scsi_pkt_lock);
1269         ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1270                                                         FC_SCSI_TM_TOV);
1271         spin_lock_bh(&fsp->scsi_pkt_lock);
1272         fsp->wait_for_comp = 0;
1273
1274         if (!ticks_left) {
1275                 FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1276         } else if (fsp->state & FC_SRB_ABORTED) {
1277                 FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1278                 rc = SUCCESS;
1279                 fc_fcp_complete_locked(fsp);
1280         }
1281
1282         return rc;
1283 }
1284
1285 /**
1286  * fc_lun_reset_send() - Send LUN reset command
1287  * @t: Timer context used to fetch the FSP packet
1288  */
1289 static void fc_lun_reset_send(struct timer_list *t)
1290 {
1291         struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1292         struct fc_lport *lport = fsp->lp;
1293
1294         if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1295                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1296                         return;
1297                 if (fc_fcp_lock_pkt(fsp))
1298                         return;
1299                 fsp->timer.function = fc_lun_reset_send;
1300                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1301                 fc_fcp_unlock_pkt(fsp);
1302         }
1303 }
1304
1305 /**
1306  * fc_lun_reset() - Send a LUN RESET command to a device
1307  *                  and wait for the reply
1308  * @lport: The local port to sent the command on
1309  * @fsp:   The FCP packet that identifies the LUN to be reset
1310  * @id:    The SCSI command ID
1311  * @lun:   The LUN ID to be reset
1312  */
1313 static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1314                         unsigned int id, unsigned int lun)
1315 {
1316         int rc;
1317
1318         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1319         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1320         int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1321
1322         fsp->wait_for_comp = 1;
1323         init_completion(&fsp->tm_done);
1324
1325         fc_lun_reset_send(&fsp->timer);
1326
1327         /*
1328          * wait for completion of reset
1329          * after that make sure all commands are terminated
1330          */
1331         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1332
1333         spin_lock_bh(&fsp->scsi_pkt_lock);
1334         fsp->state |= FC_SRB_COMPL;
1335         spin_unlock_bh(&fsp->scsi_pkt_lock);
1336
1337         del_timer_sync(&fsp->timer);
1338
1339         spin_lock_bh(&fsp->scsi_pkt_lock);
1340         if (fsp->seq_ptr) {
1341                 fc_exch_done(fsp->seq_ptr);
1342                 fsp->seq_ptr = NULL;
1343         }
1344         fsp->wait_for_comp = 0;
1345         spin_unlock_bh(&fsp->scsi_pkt_lock);
1346
1347         if (!rc) {
1348                 FC_SCSI_DBG(lport, "lun reset failed\n");
1349                 return FAILED;
1350         }
1351
1352         /* cdb_status holds the tmf's rsp code */
1353         if (fsp->cdb_status != FCP_TMF_CMPL)
1354                 return FAILED;
1355
1356         FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1357         fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1358         return SUCCESS;
1359 }
1360
1361 /**
1362  * fc_tm_done() - Task Management response handler
1363  * @seq: The sequence that the response is on
1364  * @fp:  The response frame
1365  * @arg: The FCP packet the response is for
1366  */
1367 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1368 {
1369         struct fc_fcp_pkt *fsp = arg;
1370         struct fc_frame_header *fh;
1371
1372         if (IS_ERR(fp)) {
1373                 /*
1374                  * If there is an error just let it timeout or wait
1375                  * for TMF to be aborted if it timedout.
1376                  *
1377                  * scsi-eh will escalate for when either happens.
1378                  */
1379                 return;
1380         }
1381
1382         if (fc_fcp_lock_pkt(fsp))
1383                 goto out;
1384
1385         /*
1386          * raced with eh timeout handler.
1387          */
1388         if (!fsp->seq_ptr || !fsp->wait_for_comp)
1389                 goto out_unlock;
1390
1391         fh = fc_frame_header_get(fp);
1392         if (fh->fh_type != FC_TYPE_BLS)
1393                 fc_fcp_resp(fsp, fp);
1394         fsp->seq_ptr = NULL;
1395         fc_exch_done(seq);
1396 out_unlock:
1397         fc_fcp_unlock_pkt(fsp);
1398 out:
1399         fc_frame_free(fp);
1400 }
1401
1402 /**
1403  * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1404  * @lport: The local port to be cleaned up
1405  */
1406 static void fc_fcp_cleanup(struct fc_lport *lport)
1407 {
1408         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1409 }
1410
1411 /**
1412  * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1413  * @t: Timer context used to fetch the FSP packet
1414  *
1415  * If REC is supported then just issue it and return. The REC exchange will
1416  * complete or time out and recovery can continue at that point. Otherwise,
1417  * if the response has been received without all the data it has been
1418  * ER_TIMEOUT since the response was received. If the response has not been
1419  * received we see if data was received recently. If it has been then we
1420  * continue waiting, otherwise, we abort the command.
1421  */
1422 static void fc_fcp_timeout(struct timer_list *t)
1423 {
1424         struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1425         struct fc_rport *rport = fsp->rport;
1426         struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1427
1428         if (fc_fcp_lock_pkt(fsp))
1429                 return;
1430
1431         if (fsp->cdb_cmd.fc_tm_flags)
1432                 goto unlock;
1433
1434         if (fsp->lp->qfull) {
1435                 FC_FCP_DBG(fsp, "fcp timeout, resetting timer delay %d\n",
1436                            fsp->timer_delay);
1437                 fsp->timer.function = fc_fcp_timeout;
1438                 fc_fcp_timer_set(fsp, fsp->timer_delay);
1439                 goto unlock;
1440         }
1441         FC_FCP_DBG(fsp, "fcp timeout, delay %d flags %x state %x\n",
1442                    fsp->timer_delay, rpriv->flags, fsp->state);
1443         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1444
1445         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1446                 fc_fcp_rec(fsp);
1447         else if (fsp->state & FC_SRB_RCV_STATUS)
1448                 fc_fcp_complete_locked(fsp);
1449         else
1450                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1451         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1452 unlock:
1453         fc_fcp_unlock_pkt(fsp);
1454 }
1455
1456 /**
1457  * fc_fcp_rec() - Send a REC ELS request
1458  * @fsp: The FCP packet to send the REC request on
1459  */
1460 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1461 {
1462         struct fc_lport *lport;
1463         struct fc_frame *fp;
1464         struct fc_rport *rport;
1465         struct fc_rport_libfc_priv *rpriv;
1466
1467         lport = fsp->lp;
1468         rport = fsp->rport;
1469         rpriv = rport->dd_data;
1470         if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1471                 fsp->status_code = FC_HRD_ERROR;
1472                 fsp->io_status = 0;
1473                 fc_fcp_complete_locked(fsp);
1474                 return;
1475         }
1476
1477         fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1478         if (!fp)
1479                 goto retry;
1480
1481         fr_seq(fp) = fsp->seq_ptr;
1482         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1483                        rpriv->local_port->port_id, FC_TYPE_ELS,
1484                        FC_FCTL_REQ, 0);
1485         if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1486                                  fc_fcp_rec_resp, fsp,
1487                                  2 * lport->r_a_tov)) {
1488                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1489                 return;
1490         }
1491 retry:
1492         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1493                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1494         else
1495                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1496 }
1497
1498 /**
1499  * fc_fcp_rec_resp() - Handler for REC ELS responses
1500  * @seq: The sequence the response is on
1501  * @fp:  The response frame
1502  * @arg: The FCP packet the response is on
1503  *
1504  * If the response is a reject then the scsi layer will handle
1505  * the timeout. If the response is a LS_ACC then if the I/O was not completed
1506  * set the timeout and return. If the I/O was completed then complete the
1507  * exchange and tell the SCSI layer.
1508  */
1509 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1510 {
1511         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1512         struct fc_els_rec_acc *recp;
1513         struct fc_els_ls_rjt *rjt;
1514         u32 e_stat;
1515         u8 opcode;
1516         u32 offset;
1517         enum dma_data_direction data_dir;
1518         enum fc_rctl r_ctl;
1519         struct fc_rport_libfc_priv *rpriv;
1520
1521         if (IS_ERR(fp)) {
1522                 fc_fcp_rec_error(fsp, fp);
1523                 return;
1524         }
1525
1526         if (fc_fcp_lock_pkt(fsp))
1527                 goto out;
1528
1529         fsp->recov_retry = 0;
1530         opcode = fc_frame_payload_op(fp);
1531         if (opcode == ELS_LS_RJT) {
1532                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1533                 switch (rjt->er_reason) {
1534                 default:
1535                         FC_FCP_DBG(fsp,
1536                                    "device %x invalid REC reject %d/%d\n",
1537                                    fsp->rport->port_id, rjt->er_reason,
1538                                    rjt->er_explan);
1539                         fallthrough;
1540                 case ELS_RJT_UNSUP:
1541                         FC_FCP_DBG(fsp, "device does not support REC\n");
1542                         rpriv = fsp->rport->dd_data;
1543                         /*
1544                          * if we do not spport RECs or got some bogus
1545                          * reason then resetup timer so we check for
1546                          * making progress.
1547                          */
1548                         rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1549                         break;
1550                 case ELS_RJT_LOGIC:
1551                 case ELS_RJT_UNAB:
1552                         FC_FCP_DBG(fsp, "device %x REC reject %d/%d\n",
1553                                    fsp->rport->port_id, rjt->er_reason,
1554                                    rjt->er_explan);
1555                         /*
1556                          * If response got lost or is stuck in the
1557                          * queue somewhere we have no idea if and when
1558                          * the response will be received. So quarantine
1559                          * the xid and retry the command.
1560                          */
1561                         if (rjt->er_explan == ELS_EXPL_OXID_RXID) {
1562                                 struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1563                                 ep->state |= FC_EX_QUARANTINE;
1564                                 fsp->state |= FC_SRB_ABORTED;
1565                                 fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1566                                 break;
1567                         }
1568                         fc_fcp_recovery(fsp, FC_TRANS_RESET);
1569                         break;
1570                 }
1571         } else if (opcode == ELS_LS_ACC) {
1572                 if (fsp->state & FC_SRB_ABORTED)
1573                         goto unlock_out;
1574
1575                 data_dir = fsp->cmd->sc_data_direction;
1576                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1577                 offset = ntohl(recp->reca_fc4value);
1578                 e_stat = ntohl(recp->reca_e_stat);
1579
1580                 if (e_stat & ESB_ST_COMPLETE) {
1581
1582                         /*
1583                          * The exchange is complete.
1584                          *
1585                          * For output, we must've lost the response.
1586                          * For input, all data must've been sent.
1587                          * We lost may have lost the response
1588                          * (and a confirmation was requested) and maybe
1589                          * some data.
1590                          *
1591                          * If all data received, send SRR
1592                          * asking for response.  If partial data received,
1593                          * or gaps, SRR requests data at start of gap.
1594                          * Recovery via SRR relies on in-order-delivery.
1595                          */
1596                         if (data_dir == DMA_TO_DEVICE) {
1597                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1598                         } else if (fsp->xfer_contig_end == offset) {
1599                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1600                         } else {
1601                                 offset = fsp->xfer_contig_end;
1602                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1603                         }
1604                         fc_fcp_srr(fsp, r_ctl, offset);
1605                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1606                         /*
1607                          * The remote port has the initiative, so just
1608                          * keep waiting for it to complete.
1609                          */
1610                         fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1611                 } else {
1612
1613                         /*
1614                          * The exchange is incomplete, we have seq. initiative.
1615                          * Lost response with requested confirmation,
1616                          * lost confirmation, lost transfer ready or
1617                          * lost write data.
1618                          *
1619                          * For output, if not all data was received, ask
1620                          * for transfer ready to be repeated.
1621                          *
1622                          * If we received or sent all the data, send SRR to
1623                          * request response.
1624                          *
1625                          * If we lost a response, we may have lost some read
1626                          * data as well.
1627                          */
1628                         r_ctl = FC_RCTL_DD_SOL_DATA;
1629                         if (data_dir == DMA_TO_DEVICE) {
1630                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1631                                 if (offset < fsp->data_len)
1632                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1633                         } else if (offset == fsp->xfer_contig_end) {
1634                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1635                         } else if (fsp->xfer_contig_end < offset) {
1636                                 offset = fsp->xfer_contig_end;
1637                         }
1638                         fc_fcp_srr(fsp, r_ctl, offset);
1639                 }
1640         }
1641 unlock_out:
1642         fc_fcp_unlock_pkt(fsp);
1643 out:
1644         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1645         fc_frame_free(fp);
1646 }
1647
1648 /**
1649  * fc_fcp_rec_error() - Handler for REC errors
1650  * @fsp: The FCP packet the error is on
1651  * @fp:  The REC frame
1652  */
1653 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1654 {
1655         int error = PTR_ERR(fp);
1656
1657         if (fc_fcp_lock_pkt(fsp))
1658                 goto out;
1659
1660         switch (error) {
1661         case -FC_EX_CLOSED:
1662                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange closed\n",
1663                            fsp, fsp->rport->port_id);
1664                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1665                 break;
1666
1667         default:
1668                 FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1669                            fsp, fsp->rport->port_id, error);
1670                 fsp->status_code = FC_CMD_PLOGO;
1671                 fallthrough;
1672
1673         case -FC_EX_TIMEOUT:
1674                 /*
1675                  * Assume REC or LS_ACC was lost.
1676                  * The exchange manager will have aborted REC, so retry.
1677                  */
1678                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange timeout retry %d/%d\n",
1679                            fsp, fsp->rport->port_id, fsp->recov_retry,
1680                            FC_MAX_RECOV_RETRY);
1681                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1682                         fc_fcp_rec(fsp);
1683                 else
1684                         fc_fcp_recovery(fsp, FC_ERROR);
1685                 break;
1686         }
1687         fc_fcp_unlock_pkt(fsp);
1688 out:
1689         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1690 }
1691
1692 /**
1693  * fc_fcp_recovery() - Handler for fcp_pkt recovery
1694  * @fsp: The FCP pkt that needs to be aborted
1695  * @code: The FCP status code to set
1696  */
1697 static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1698 {
1699         FC_FCP_DBG(fsp, "start recovery code %x\n", code);
1700         fsp->status_code = code;
1701         fsp->cdb_status = 0;
1702         fsp->io_status = 0;
1703         /*
1704          * if this fails then we let the scsi command timer fire and
1705          * scsi-ml escalate.
1706          */
1707         fc_fcp_send_abort(fsp);
1708 }
1709
1710 /**
1711  * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1712  * @fsp:   The FCP packet the SRR is to be sent on
1713  * @r_ctl: The R_CTL field for the SRR request
1714  * @offset: The SRR relative offset
1715  * This is called after receiving status but insufficient data, or
1716  * when expecting status but the request has timed out.
1717  */
1718 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1719 {
1720         struct fc_lport *lport = fsp->lp;
1721         struct fc_rport *rport;
1722         struct fc_rport_libfc_priv *rpriv;
1723         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1724         struct fc_seq *seq;
1725         struct fcp_srr *srr;
1726         struct fc_frame *fp;
1727
1728         rport = fsp->rport;
1729         rpriv = rport->dd_data;
1730
1731         if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1732             rpriv->rp_state != RPORT_ST_READY)
1733                 goto retry;                     /* shouldn't happen */
1734         fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1735         if (!fp)
1736                 goto retry;
1737
1738         srr = fc_frame_payload_get(fp, sizeof(*srr));
1739         memset(srr, 0, sizeof(*srr));
1740         srr->srr_op = ELS_SRR;
1741         srr->srr_ox_id = htons(ep->oxid);
1742         srr->srr_rx_id = htons(ep->rxid);
1743         srr->srr_r_ctl = r_ctl;
1744         srr->srr_rel_off = htonl(offset);
1745
1746         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1747                        rpriv->local_port->port_id, FC_TYPE_FCP,
1748                        FC_FCTL_REQ, 0);
1749
1750         seq = fc_exch_seq_send(lport, fp, fc_fcp_srr_resp,
1751                                fc_fcp_pkt_destroy,
1752                                fsp, get_fsp_rec_tov(fsp));
1753         if (!seq)
1754                 goto retry;
1755
1756         fsp->recov_seq = seq;
1757         fsp->xfer_len = offset;
1758         fsp->xfer_contig_end = offset;
1759         fsp->state &= ~FC_SRB_RCV_STATUS;
1760         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1761         return;
1762 retry:
1763         fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1764 }
1765
1766 /**
1767  * fc_fcp_srr_resp() - Handler for SRR response
1768  * @seq: The sequence the SRR is on
1769  * @fp:  The SRR frame
1770  * @arg: The FCP packet the SRR is on
1771  */
1772 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1773 {
1774         struct fc_fcp_pkt *fsp = arg;
1775         struct fc_frame_header *fh;
1776
1777         if (IS_ERR(fp)) {
1778                 fc_fcp_srr_error(fsp, fp);
1779                 return;
1780         }
1781
1782         if (fc_fcp_lock_pkt(fsp))
1783                 goto out;
1784
1785         fh = fc_frame_header_get(fp);
1786         /*
1787          * BUG? fc_fcp_srr_error calls fc_exch_done which would release
1788          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1789          * then fc_exch_timeout would be sending an abort. The fc_exch_done
1790          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1791          * an abort response though.
1792          */
1793         if (fh->fh_type == FC_TYPE_BLS) {
1794                 fc_fcp_unlock_pkt(fsp);
1795                 return;
1796         }
1797
1798         switch (fc_frame_payload_op(fp)) {
1799         case ELS_LS_ACC:
1800                 fsp->recov_retry = 0;
1801                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1802                 break;
1803         case ELS_LS_RJT:
1804         default:
1805                 fc_fcp_recovery(fsp, FC_ERROR);
1806                 break;
1807         }
1808         fc_fcp_unlock_pkt(fsp);
1809 out:
1810         fc_exch_done(seq);
1811         fc_frame_free(fp);
1812 }
1813
1814 /**
1815  * fc_fcp_srr_error() - Handler for SRR errors
1816  * @fsp: The FCP packet that the SRR error is on
1817  * @fp:  The SRR frame
1818  */
1819 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1820 {
1821         if (fc_fcp_lock_pkt(fsp))
1822                 goto out;
1823         switch (PTR_ERR(fp)) {
1824         case -FC_EX_TIMEOUT:
1825                 FC_FCP_DBG(fsp, "SRR timeout, retries %d\n", fsp->recov_retry);
1826                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1827                         fc_fcp_rec(fsp);
1828                 else
1829                         fc_fcp_recovery(fsp, FC_TIMED_OUT);
1830                 break;
1831         case -FC_EX_CLOSED:                     /* e.g., link failure */
1832                 FC_FCP_DBG(fsp, "SRR error, exchange closed\n");
1833                 fallthrough;
1834         default:
1835                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1836                 break;
1837         }
1838         fc_fcp_unlock_pkt(fsp);
1839 out:
1840         fc_exch_done(fsp->recov_seq);
1841 }
1842
1843 /**
1844  * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1845  * @lport: The local port to be checked
1846  */
1847 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1848 {
1849         /* lock ? */
1850         return (lport->state == LPORT_ST_READY) &&
1851                 lport->link_up && !lport->qfull;
1852 }
1853
1854 /**
1855  * fc_queuecommand() - The queuecommand function of the SCSI template
1856  * @shost: The Scsi_Host that the command was issued to
1857  * @sc_cmd:   The scsi_cmnd to be executed
1858  *
1859  * This is the i/o strategy routine, called by the SCSI layer.
1860  */
1861 int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1862 {
1863         struct fc_lport *lport = shost_priv(shost);
1864         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1865         struct fc_fcp_pkt *fsp;
1866         int rval;
1867         int rc = 0;
1868         struct fc_stats *stats;
1869
1870         rval = fc_remote_port_chkready(rport);
1871         if (rval) {
1872                 sc_cmd->result = rval;
1873                 sc_cmd->scsi_done(sc_cmd);
1874                 return 0;
1875         }
1876
1877         if (!*(struct fc_remote_port **)rport->dd_data) {
1878                 /*
1879                  * rport is transitioning from blocked/deleted to
1880                  * online
1881                  */
1882                 sc_cmd->result = DID_IMM_RETRY << 16;
1883                 sc_cmd->scsi_done(sc_cmd);
1884                 goto out;
1885         }
1886
1887         if (!fc_fcp_lport_queue_ready(lport)) {
1888                 if (lport->qfull) {
1889                         if (fc_fcp_can_queue_ramp_down(lport))
1890                                 shost_printk(KERN_ERR, lport->host,
1891                                              "libfc: queue full, "
1892                                              "reducing can_queue to %d.\n",
1893                                              lport->host->can_queue);
1894                 }
1895                 rc = SCSI_MLQUEUE_HOST_BUSY;
1896                 goto out;
1897         }
1898
1899         fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1900         if (fsp == NULL) {
1901                 rc = SCSI_MLQUEUE_HOST_BUSY;
1902                 goto out;
1903         }
1904
1905         /*
1906          * build the libfc request pkt
1907          */
1908         fsp->cmd = sc_cmd;      /* save the cmd */
1909         fsp->rport = rport;     /* set the remote port ptr */
1910
1911         /*
1912          * set up the transfer length
1913          */
1914         fsp->data_len = scsi_bufflen(sc_cmd);
1915         fsp->xfer_len = 0;
1916
1917         /*
1918          * setup the data direction
1919          */
1920         stats = per_cpu_ptr(lport->stats, get_cpu());
1921         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1922                 fsp->req_flags = FC_SRB_READ;
1923                 stats->InputRequests++;
1924                 stats->InputBytes += fsp->data_len;
1925         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1926                 fsp->req_flags = FC_SRB_WRITE;
1927                 stats->OutputRequests++;
1928                 stats->OutputBytes += fsp->data_len;
1929         } else {
1930                 fsp->req_flags = 0;
1931                 stats->ControlRequests++;
1932         }
1933         put_cpu();
1934
1935         /*
1936          * send it to the lower layer
1937          * if we get -1 return then put the request in the pending
1938          * queue.
1939          */
1940         rval = fc_fcp_pkt_send(lport, fsp);
1941         if (rval != 0) {
1942                 fsp->state = FC_SRB_FREE;
1943                 fc_fcp_pkt_release(fsp);
1944                 rc = SCSI_MLQUEUE_HOST_BUSY;
1945         }
1946 out:
1947         return rc;
1948 }
1949 EXPORT_SYMBOL(fc_queuecommand);
1950
1951 /**
1952  * fc_io_compl() - Handle responses for completed commands
1953  * @fsp: The FCP packet that is complete
1954  *
1955  * Translates fcp_pkt errors to a Linux SCSI errors.
1956  * The fcp packet lock must be held when calling.
1957  */
1958 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1959 {
1960         struct fc_fcp_internal *si;
1961         struct scsi_cmnd *sc_cmd;
1962         struct fc_lport *lport;
1963         unsigned long flags;
1964
1965         /* release outstanding ddp context */
1966         fc_fcp_ddp_done(fsp);
1967
1968         fsp->state |= FC_SRB_COMPL;
1969         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1970                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1971                 del_timer_sync(&fsp->timer);
1972                 spin_lock_bh(&fsp->scsi_pkt_lock);
1973         }
1974
1975         lport = fsp->lp;
1976         si = fc_get_scsi_internal(lport);
1977
1978         /*
1979          * if can_queue ramp down is done then try can_queue ramp up
1980          * since commands are completing now.
1981          */
1982         if (si->last_can_queue_ramp_down_time)
1983                 fc_fcp_can_queue_ramp_up(lport);
1984
1985         sc_cmd = fsp->cmd;
1986         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1987         switch (fsp->status_code) {
1988         case FC_COMPLETE:
1989                 if (fsp->cdb_status == 0) {
1990                         /*
1991                          * good I/O status
1992                          */
1993                         sc_cmd->result = DID_OK << 16;
1994                         if (fsp->scsi_resid)
1995                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1996                 } else {
1997                         /*
1998                          * transport level I/O was ok but scsi
1999                          * has non zero status
2000                          */
2001                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
2002                 }
2003                 break;
2004         case FC_ERROR:
2005                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2006                            "due to FC_ERROR\n");
2007                 sc_cmd->result = DID_ERROR << 16;
2008                 break;
2009         case FC_DATA_UNDRUN:
2010                 if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
2011                         /*
2012                          * scsi status is good but transport level
2013                          * underrun.
2014                          */
2015                         if (fsp->state & FC_SRB_RCV_STATUS) {
2016                                 sc_cmd->result = DID_OK << 16;
2017                         } else {
2018                                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
2019                                            " due to FC_DATA_UNDRUN (trans)\n");
2020                                 sc_cmd->result = DID_ERROR << 16;
2021                         }
2022                 } else {
2023                         /*
2024                          * scsi got underrun, this is an error
2025                          */
2026                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2027                                    "due to FC_DATA_UNDRUN (scsi)\n");
2028                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2029                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2030                 }
2031                 break;
2032         case FC_DATA_OVRRUN:
2033                 /*
2034                  * overrun is an error
2035                  */
2036                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2037                            "due to FC_DATA_OVRRUN\n");
2038                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2039                 break;
2040         case FC_CMD_ABORTED:
2041                 if (host_byte(sc_cmd->result) == DID_TIME_OUT)
2042                         FC_FCP_DBG(fsp, "Returning DID_TIME_OUT to scsi-ml "
2043                                    "due to FC_CMD_ABORTED\n");
2044                 else {
2045                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2046                                    "due to FC_CMD_ABORTED\n");
2047                         set_host_byte(sc_cmd, DID_ERROR);
2048                 }
2049                 sc_cmd->result |= fsp->io_status;
2050                 break;
2051         case FC_CMD_RESET:
2052                 FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
2053                            "due to FC_CMD_RESET\n");
2054                 sc_cmd->result = (DID_RESET << 16);
2055                 break;
2056         case FC_TRANS_RESET:
2057                 FC_FCP_DBG(fsp, "Returning DID_SOFT_ERROR to scsi-ml "
2058                            "due to FC_TRANS_RESET\n");
2059                 sc_cmd->result = (DID_SOFT_ERROR << 16);
2060                 break;
2061         case FC_HRD_ERROR:
2062                 FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
2063                            "due to FC_HRD_ERROR\n");
2064                 sc_cmd->result = (DID_NO_CONNECT << 16);
2065                 break;
2066         case FC_CRC_ERROR:
2067                 FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
2068                            "due to FC_CRC_ERROR\n");
2069                 sc_cmd->result = (DID_PARITY << 16);
2070                 break;
2071         case FC_TIMED_OUT:
2072                 FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
2073                            "due to FC_TIMED_OUT\n");
2074                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
2075                 break;
2076         default:
2077                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2078                            "due to unknown error\n");
2079                 sc_cmd->result = (DID_ERROR << 16);
2080                 break;
2081         }
2082
2083         if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2084                 sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2085
2086         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2087         list_del(&fsp->list);
2088         sc_cmd->SCp.ptr = NULL;
2089         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2090         sc_cmd->scsi_done(sc_cmd);
2091
2092         /* release ref from initial allocation in queue command */
2093         fc_fcp_pkt_release(fsp);
2094 }
2095
2096 /**
2097  * fc_eh_abort() - Abort a command
2098  * @sc_cmd: The SCSI command to abort
2099  *
2100  * From SCSI host template.
2101  * Send an ABTS to the target device and wait for the response.
2102  */
2103 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2104 {
2105         struct fc_fcp_pkt *fsp;
2106         struct fc_lport *lport;
2107         struct fc_fcp_internal *si;
2108         int rc = FAILED;
2109         unsigned long flags;
2110         int rval;
2111
2112         rval = fc_block_scsi_eh(sc_cmd);
2113         if (rval)
2114                 return rval;
2115
2116         lport = shost_priv(sc_cmd->device->host);
2117         if (lport->state != LPORT_ST_READY)
2118                 return rc;
2119         else if (!lport->link_up)
2120                 return rc;
2121
2122         si = fc_get_scsi_internal(lport);
2123         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2124         fsp = CMD_SP(sc_cmd);
2125         if (!fsp) {
2126                 /* command completed while scsi eh was setting up */
2127                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2128                 return SUCCESS;
2129         }
2130         /* grab a ref so the fsp and sc_cmd cannot be released from under us */
2131         fc_fcp_pkt_hold(fsp);
2132         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2133
2134         if (fc_fcp_lock_pkt(fsp)) {
2135                 /* completed while we were waiting for timer to be deleted */
2136                 rc = SUCCESS;
2137                 goto release_pkt;
2138         }
2139
2140         rc = fc_fcp_pkt_abort(fsp);
2141         fc_fcp_unlock_pkt(fsp);
2142
2143 release_pkt:
2144         fc_fcp_pkt_release(fsp);
2145         return rc;
2146 }
2147 EXPORT_SYMBOL(fc_eh_abort);
2148
2149 /**
2150  * fc_eh_device_reset() - Reset a single LUN
2151  * @sc_cmd: The SCSI command which identifies the device whose
2152  *          LUN is to be reset
2153  *
2154  * Set from SCSI host template.
2155  */
2156 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2157 {
2158         struct fc_lport *lport;
2159         struct fc_fcp_pkt *fsp;
2160         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2161         int rc = FAILED;
2162         int rval;
2163
2164         rval = fc_block_scsi_eh(sc_cmd);
2165         if (rval)
2166                 return rval;
2167
2168         lport = shost_priv(sc_cmd->device->host);
2169
2170         if (lport->state != LPORT_ST_READY)
2171                 return rc;
2172
2173         FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2174
2175         fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2176         if (fsp == NULL) {
2177                 printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2178                 goto out;
2179         }
2180
2181         /*
2182          * Build the libfc request pkt. Do not set the scsi cmnd, because
2183          * the sc passed in is not setup for execution like when sent
2184          * through the queuecommand callout.
2185          */
2186         fsp->rport = rport;     /* set the remote port ptr */
2187
2188         /*
2189          * flush outstanding commands
2190          */
2191         rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2192         fsp->state = FC_SRB_FREE;
2193         fc_fcp_pkt_release(fsp);
2194
2195 out:
2196         return rc;
2197 }
2198 EXPORT_SYMBOL(fc_eh_device_reset);
2199
2200 /**
2201  * fc_eh_host_reset() - Reset a Scsi_Host.
2202  * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2203  */
2204 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2205 {
2206         struct Scsi_Host *shost = sc_cmd->device->host;
2207         struct fc_lport *lport = shost_priv(shost);
2208         unsigned long wait_tmo;
2209
2210         FC_SCSI_DBG(lport, "Resetting host\n");
2211
2212         fc_lport_reset(lport);
2213         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2214         while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2215                                                                wait_tmo))
2216                 msleep(1000);
2217
2218         if (fc_fcp_lport_queue_ready(lport)) {
2219                 shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2220                              "on port (%6.6x)\n", lport->port_id);
2221                 return SUCCESS;
2222         } else {
2223                 shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2224                              "port (%6.6x) is not ready.\n",
2225                              lport->port_id);
2226                 return FAILED;
2227         }
2228 }
2229 EXPORT_SYMBOL(fc_eh_host_reset);
2230
2231 /**
2232  * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2233  * @sdev: The SCSI device that identifies the SCSI host
2234  *
2235  * Configures queue depth based on host's cmd_per_len. If not set
2236  * then we use the libfc default.
2237  */
2238 int fc_slave_alloc(struct scsi_device *sdev)
2239 {
2240         struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2241
2242         if (!rport || fc_remote_port_chkready(rport))
2243                 return -ENXIO;
2244
2245         scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2246         return 0;
2247 }
2248 EXPORT_SYMBOL(fc_slave_alloc);
2249
2250 /**
2251  * fc_fcp_destory() - Tear down the FCP layer for a given local port
2252  * @lport: The local port that no longer needs the FCP layer
2253  */
2254 void fc_fcp_destroy(struct fc_lport *lport)
2255 {
2256         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2257
2258         if (!list_empty(&si->scsi_pkt_queue))
2259                 printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2260                        "port (%6.6x)\n", lport->port_id);
2261
2262         mempool_destroy(si->scsi_pkt_pool);
2263         kfree(si);
2264         lport->scsi_priv = NULL;
2265 }
2266 EXPORT_SYMBOL(fc_fcp_destroy);
2267
2268 int fc_setup_fcp(void)
2269 {
2270         int rc = 0;
2271
2272         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2273                                             sizeof(struct fc_fcp_pkt),
2274                                             0, SLAB_HWCACHE_ALIGN, NULL);
2275         if (!scsi_pkt_cachep) {
2276                 printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2277                        "module load failed!");
2278                 rc = -ENOMEM;
2279         }
2280
2281         return rc;
2282 }
2283
2284 void fc_destroy_fcp(void)
2285 {
2286         kmem_cache_destroy(scsi_pkt_cachep);
2287 }
2288
2289 /**
2290  * fc_fcp_init() - Initialize the FCP layer for a local port
2291  * @lport: The local port to initialize the exchange layer for
2292  */
2293 int fc_fcp_init(struct fc_lport *lport)
2294 {
2295         int rc;
2296         struct fc_fcp_internal *si;
2297
2298         if (!lport->tt.fcp_cmd_send)
2299                 lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2300
2301         if (!lport->tt.fcp_cleanup)
2302                 lport->tt.fcp_cleanup = fc_fcp_cleanup;
2303
2304         if (!lport->tt.fcp_abort_io)
2305                 lport->tt.fcp_abort_io = fc_fcp_abort_io;
2306
2307         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2308         if (!si)
2309                 return -ENOMEM;
2310         lport->scsi_priv = si;
2311         si->max_can_queue = lport->host->can_queue;
2312         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2313         spin_lock_init(&si->scsi_queue_lock);
2314
2315         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2316         if (!si->scsi_pkt_pool) {
2317                 rc = -ENOMEM;
2318                 goto free_internal;
2319         }
2320         return 0;
2321
2322 free_internal:
2323         kfree(si);
2324         return rc;
2325 }
2326 EXPORT_SYMBOL(fc_fcp_init);