linux/drivers/scsi/libfc/fc_fcp.c
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   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
  33static 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 */
  66struct 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 */
  81static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  82static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  83static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  84static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  85static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  86static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
  87static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
  88static void fc_fcp_timeout(struct timer_list *);
  89static void fc_fcp_rec(struct fc_fcp_pkt *);
  90static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
  91static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
  92static void fc_io_compl(struct fc_fcp_pkt *);
  93
  94static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
  95static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
  96static 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 */
 135static 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 */
 163static 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 */
 176static 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 */
 192static 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 */
 214static 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 */
 231static 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 */
 242static 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
 250static 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 */
 266static 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 */
 299static 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 */
 317void 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 */
 335void 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 */
 356static 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
 384unlock:
 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 */
 398static 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
 421unlock:
 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 */
 434static 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 */
 459static 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 */
 474static 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))) {
 539crc_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;
 577err:
 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 */
 594static 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 */
 741static 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 */
 778static 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        }
 842unlock:
 843        fc_fcp_unlock_pkt(fsp);
 844out:
 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 */
 853static 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
 967len_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);
 970err:
 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 */
 983static 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 */
1046static 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 */
1064static 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);
1073restart:
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 */
1121static 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 */
1134static 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 */
1167static 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
1210unlock:
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 */
1220static 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);
1239unlock:
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 */
1249static 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 */
1289static 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 */
1313static 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 */
1367static 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);
1396out_unlock:
1397        fc_fcp_unlock_pkt(fsp);
1398out:
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 */
1406static 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 */
1422static 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;
1452unlock:
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 */
1460static 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        }
1491retry:
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 */
1509static 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        }
1641unlock_out:
1642        fc_fcp_unlock_pkt(fsp);
1643out:
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 */
1653static 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);
1688out:
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 */
1697static 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 */
1718static 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;
1762retry:
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 */
1772static 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);
1809out:
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 */
1819static 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);
1839out:
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 */
1847static 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 */
1861int 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        }
1946out:
1947        return rc;
1948}
1949EXPORT_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 */
1958static 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 */
2103int 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
2143release_pkt:
2144        fc_fcp_pkt_release(fsp);
2145        return rc;
2146}
2147EXPORT_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 */
2156int 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
2195out:
2196        return rc;
2197}
2198EXPORT_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 */
2204int 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}
2229EXPORT_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 */
2238int 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}
2248EXPORT_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 */
2254void 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}
2266EXPORT_SYMBOL(fc_fcp_destroy);
2267
2268int 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
2284void 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 */
2293int 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
2322free_internal:
2323        kfree(si);
2324        return rc;
2325}
2326EXPORT_SYMBOL(fc_fcp_init);
2327