1/*
   2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
   3 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
   4 * Copyright(c) 2008 Mike Christie
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms and conditions of the GNU General Public License,
   8 * version 2, as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope it will be useful, but WITHOUT
  11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 * more details.
  14 *
  15 * You should have received a copy of the GNU General Public License along with
  16 * this program; if not, write to the Free Software Foundation, Inc.,
  17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18 *
  19 * Maintained at www.Open-FCoE.org
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/delay.h>
  24#include <linux/kernel.h>
  25#include <linux/types.h>
  26#include <linux/spinlock.h>
  27#include <linux/scatterlist.h>
  28#include <linux/err.h>
  29#include <linux/crc32.h>
  30#include <linux/slab.h>
  31
  32#include <scsi/scsi_tcq.h>
  33#include <scsi/scsi.h>
  34#include <scsi/scsi_host.h>
  35#include <scsi/scsi_device.h>
  36#include <scsi/scsi_cmnd.h>
  37
  38#include <scsi/fc/fc_fc2.h>
  39
  40#include <scsi/libfc.h>
  41#include <scsi/fc_encode.h>
  42
  43#include "fc_libfc.h"
  44
  45static struct kmem_cache *scsi_pkt_cachep;
  46
  47/* SRB state definitions */
  48#define FC_SRB_FREE		0		/* cmd is free */
  49#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
  50#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
  51#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
  52#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
  53#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
  54#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
  55#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
  56
  57#define FC_SRB_READ		(1 << 1)
  58#define FC_SRB_WRITE		(1 << 0)
  59
  60/*
  61 * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
  62 */
  63#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
  64#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
  65#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
  66#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
  67#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
  68
  69/**
  70 * struct fc_fcp_internal - FCP layer internal data
  71 * @scsi_pkt_pool: Memory pool to draw FCP packets from
  72 * @scsi_queue_lock: Protects the scsi_pkt_queue
  73 * @scsi_pkt_queue: Current FCP packets
  74 * @last_can_queue_ramp_down_time: ramp down time
  75 * @last_can_queue_ramp_up_time: ramp up time
  76 * @max_can_queue: max can_queue size
  77 */
  78struct fc_fcp_internal {
  79	mempool_t		*scsi_pkt_pool;
  80	spinlock_t		scsi_queue_lock;
  81	struct list_head	scsi_pkt_queue;
  82	unsigned long		last_can_queue_ramp_down_time;
  83	unsigned long		last_can_queue_ramp_up_time;
  84	int			max_can_queue;
  85};
  86
  87#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
  88
  89/*
  90 * function prototypes
  91 * FC scsi I/O related functions
  92 */
  93static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
  94static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
  95static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
  96static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
  97static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
  98static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
  99static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
 100static void fc_fcp_timeout(unsigned long);
 101static void fc_fcp_rec(struct fc_fcp_pkt *);
 102static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
 103static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
 104static void fc_io_compl(struct fc_fcp_pkt *);
 105
 106static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
 107static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
 108static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
 109
 110/*
 111 * command status codes
 112 */
 113#define FC_COMPLETE		0
 114#define FC_CMD_ABORTED		1
 115#define FC_CMD_RESET		2
 116#define FC_CMD_PLOGO		3
 117#define FC_SNS_RCV		4
 118#define FC_TRANS_ERR		5
 119#define FC_DATA_OVRRUN		6
 120#define FC_DATA_UNDRUN		7
 121#define FC_ERROR		8
 122#define FC_HRD_ERROR		9
 123#define FC_CRC_ERROR		10
 124#define FC_TIMED_OUT		11
 125
 126/*
 127 * Error recovery timeout values.
 128 */
 129#define FC_SCSI_TM_TOV		(10 * HZ)
 130#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
 131#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
 132
 133#define FC_MAX_ERROR_CNT	5
 134#define FC_MAX_RECOV_RETRY	3
 135
 136#define FC_FCP_DFLT_QUEUE_DEPTH 32
 137
 138/**
 139 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
 140 * @lport: The local port that the FCP packet is for
 141 * @gfp:   GFP flags for allocation
 142 *
 143 * Return value: fcp_pkt structure or null on allocation failure.
 144 * Context:	 Can be called from process context, no lock is required.
 145 */
 146static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
 147{
 148	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 149	struct fc_fcp_pkt *fsp;
 150
 151	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
 152	if (fsp) {
 153		memset(fsp, 0, sizeof(*fsp));
 154		fsp->lp = lport;
 155		fsp->xfer_ddp = FC_XID_UNKNOWN;
 156		atomic_set(&fsp->ref_cnt, 1);
 157		init_timer(&fsp->timer);
 
 158		INIT_LIST_HEAD(&fsp->list);
 159		spin_lock_init(&fsp->scsi_pkt_lock);
 160	}
 161	return fsp;
 162}
 163
 164/**
 165 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
 166 * @fsp: The FCP packet to be released
 167 *
 168 * Context: Can be called from process or interrupt context,
 169 *	    no lock is required.
 170 */
 171static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
 172{
 173	if (atomic_dec_and_test(&fsp->ref_cnt)) {
 174		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
 175
 176		mempool_free(fsp, si->scsi_pkt_pool);
 177	}
 178}
 179
 180/**
 181 * fc_fcp_pkt_hold() - Hold a fcp_pkt
 182 * @fsp: The FCP packet to be held
 183 */
 184static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
 185{
 186	atomic_inc(&fsp->ref_cnt);
 187}
 188
 189/**
 190 * fc_fcp_pkt_destory() - Release hold on a fcp_pkt
 191 * @seq: The sequence that the FCP packet is on (required by destructor API)
 192 * @fsp: The FCP packet to be released
 193 *
 194 * This routine is called by a destructor callback in the exch_seq_send()
 195 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
 196 * argument even though it is not used by this routine.
 197 *
 198 * Context: No locking required.
 199 */
 200static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
 201{
 202	fc_fcp_pkt_release(fsp);
 203}
 204
 205/**
 206 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
 207 * @fsp: The FCP packet to be locked and incremented
 208 *
 209 * We should only return error if we return a command to SCSI-ml before
 210 * getting a response. This can happen in cases where we send a abort, but
 211 * do not wait for the response and the abort and command can be passing
 212 * each other on the wire/network-layer.
 213 *
 214 * Note: this function locks the packet and gets a reference to allow
 215 * callers to call the completion function while the lock is held and
 216 * not have to worry about the packets refcount.
 217 *
 218 * TODO: Maybe we should just have callers grab/release the lock and
 219 * have a function that they call to verify the fsp and grab a ref if
 220 * needed.
 221 */
 222static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
 223{
 224	spin_lock_bh(&fsp->scsi_pkt_lock);
 225	if (fsp->state & FC_SRB_COMPL) {
 226		spin_unlock_bh(&fsp->scsi_pkt_lock);
 227		return -EPERM;
 228	}
 229
 230	fc_fcp_pkt_hold(fsp);
 231	return 0;
 232}
 233
 234/**
 235 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
 236 *			 reference count
 237 * @fsp: The FCP packet to be unlocked and decremented
 238 */
 239static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
 240{
 241	spin_unlock_bh(&fsp->scsi_pkt_lock);
 242	fc_fcp_pkt_release(fsp);
 243}
 244
 245/**
 246 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
 247 * @fsp:   The FCP packet to start a timer for
 248 * @delay: The timeout period in jiffies
 249 */
 250static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
 251{
 252	if (!(fsp->state & FC_SRB_COMPL))
 253		mod_timer(&fsp->timer, jiffies + delay);
 254}
 255
 256/**
 257 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
 258 *			 fcp_pkt
 259 * @fsp: The FCP packet to abort exchanges on
 260 */
 261static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
 262{
 263	if (!fsp->seq_ptr)
 264		return -EINVAL;
 265
 266	fsp->state |= FC_SRB_ABORT_PENDING;
 267	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
 268}
 269
 270/**
 271 * fc_fcp_retry_cmd() - Retry a fcp_pkt
 272 * @fsp: The FCP packet to be retried
 273 *
 274 * Sets the status code to be FC_ERROR and then calls
 275 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
 276 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
 277 * The SCSI-ml will retry the command.
 278 */
 279static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
 280{
 281	if (fsp->seq_ptr) {
 282		fsp->lp->tt.exch_done(fsp->seq_ptr);
 283		fsp->seq_ptr = NULL;
 284	}
 285
 286	fsp->state &= ~FC_SRB_ABORT_PENDING;
 287	fsp->io_status = 0;
 288	fsp->status_code = FC_ERROR;
 289	fc_fcp_complete_locked(fsp);
 290}
 291
 292/**
 293 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
 294 * @fsp: The FCP packet that will manage the DDP frames
 295 * @xid: The XID that will be used for the DDP exchange
 296 */
 297void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
 298{
 299	struct fc_lport *lport;
 300
 301	lport = fsp->lp;
 302	if ((fsp->req_flags & FC_SRB_READ) &&
 303	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
 304		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
 305					scsi_sg_count(fsp->cmd)))
 306			fsp->xfer_ddp = xid;
 307	}
 308}
 309
 310/**
 311 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
 312 *		       DDP related resources for a fcp_pkt
 313 * @fsp: The FCP packet that DDP had been used on
 314 */
 315void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
 316{
 317	struct fc_lport *lport;
 318
 319	if (!fsp)
 320		return;
 321
 322	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
 323		return;
 324
 325	lport = fsp->lp;
 326	if (lport->tt.ddp_done) {
 327		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
 328		fsp->xfer_ddp = FC_XID_UNKNOWN;
 329	}
 330}
 331
 332/**
 333 * fc_fcp_can_queue_ramp_up() - increases can_queue
 334 * @lport: lport to ramp up can_queue
 335 */
 336static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
 337{
 338	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 339	unsigned long flags;
 340	int can_queue;
 341
 342	spin_lock_irqsave(lport->host->host_lock, flags);
 343
 344	if (si->last_can_queue_ramp_up_time &&
 345	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
 346			 FC_CAN_QUEUE_PERIOD)))
 347		goto unlock;
 348
 349	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
 350			FC_CAN_QUEUE_PERIOD))
 351		goto unlock;
 352
 353	si->last_can_queue_ramp_up_time = jiffies;
 354
 355	can_queue = lport->host->can_queue << 1;
 356	if (can_queue >= si->max_can_queue) {
 357		can_queue = si->max_can_queue;
 358		si->last_can_queue_ramp_down_time = 0;
 359	}
 360	lport->host->can_queue = can_queue;
 361	shost_printk(KERN_ERR, lport->host, "libfc: increased "
 362		     "can_queue to %d.\n", can_queue);
 363
 364unlock:
 365	spin_unlock_irqrestore(lport->host->host_lock, flags);
 366}
 367
 368/**
 369 * fc_fcp_can_queue_ramp_down() - reduces can_queue
 370 * @lport: lport to reduce can_queue
 371 *
 372 * If we are getting memory allocation failures, then we may
 373 * be trying to execute too many commands. We let the running
 374 * commands complete or timeout, then try again with a reduced
 375 * can_queue. Eventually we will hit the point where we run
 376 * on all reserved structs.
 377 */
 378static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
 379{
 380	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
 381	unsigned long flags;
 382	int can_queue;
 383
 384	spin_lock_irqsave(lport->host->host_lock, flags);
 385
 386	if (si->last_can_queue_ramp_down_time &&
 387	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
 388			 FC_CAN_QUEUE_PERIOD)))
 389		goto unlock;
 390
 391	si->last_can_queue_ramp_down_time = jiffies;
 392
 393	can_queue = lport->host->can_queue;
 394	can_queue >>= 1;
 395	if (!can_queue)
 396		can_queue = 1;
 397	lport->host->can_queue = can_queue;
 398	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
 399		     "Reducing can_queue to %d.\n", can_queue);
 400
 401unlock:
 402	spin_unlock_irqrestore(lport->host->host_lock, flags);
 403}
 404
 405/*
 406 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
 407 * @lport:	fc lport struct
 408 * @len:	payload length
 409 *
 410 * Allocates fc_frame structure and buffer but if fails to allocate
 411 * then reduce can_queue.
 412 */
 413static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
 414						  size_t len)
 415{
 416	struct fc_frame *fp;
 417
 418	fp = fc_frame_alloc(lport, len);
 419	if (likely(fp))
 420		return fp;
 421
 422	/* error case */
 423	fc_fcp_can_queue_ramp_down(lport);
 424	return NULL;
 425}
 426
 427/**
 428 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
 429 * @fsp: The FCP packet the data is on
 430 * @fp:	 The data frame
 431 */
 432static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 433{
 434	struct scsi_cmnd *sc = fsp->cmd;
 435	struct fc_lport *lport = fsp->lp;
 436	struct fcoe_dev_stats *stats;
 437	struct fc_frame_header *fh;
 438	size_t start_offset;
 439	size_t offset;
 440	u32 crc;
 441	u32 copy_len = 0;
 442	size_t len;
 443	void *buf;
 444	struct scatterlist *sg;
 445	u32 nents;
 446	u8 host_bcode = FC_COMPLETE;
 447
 448	fh = fc_frame_header_get(fp);
 449	offset = ntohl(fh->fh_parm_offset);
 450	start_offset = offset;
 451	len = fr_len(fp) - sizeof(*fh);
 452	buf = fc_frame_payload_get(fp, 0);
 453
 454	/*
 455	 * if this I/O is ddped then clear it and initiate recovery since data
 456	 * frames are expected to be placed directly in that case.
 457	 *
 458	 * Indicate error to scsi-ml because something went wrong with the
 459	 * ddp handling to get us here.
 460	 */
 461	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
 462		fc_fcp_ddp_done(fsp);
 463		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
 464		host_bcode = FC_ERROR;
 465		goto err;
 466	}
 467	if (offset + len > fsp->data_len) {
 468		/* this should never happen */
 469		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
 470		    fc_frame_crc_check(fp))
 471			goto crc_err;
 472		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
 473			   "data_len %x\n", len, offset, fsp->data_len);
 474
 475		/* Data is corrupted indicate scsi-ml should retry */
 476		host_bcode = FC_DATA_OVRRUN;
 477		goto err;
 478	}
 479	if (offset != fsp->xfer_len)
 480		fsp->state |= FC_SRB_DISCONTIG;
 481
 482	sg = scsi_sglist(sc);
 483	nents = scsi_sg_count(sc);
 484
 485	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
 486		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 487						    &offset, KM_SOFTIRQ0, NULL);
 488	} else {
 489		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
 490		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
 491						    &offset, KM_SOFTIRQ0, &crc);
 492		buf = fc_frame_payload_get(fp, 0);
 493		if (len % 4)
 494			crc = crc32(crc, buf + len, 4 - (len % 4));
 495
 496		if (~crc != le32_to_cpu(fr_crc(fp))) {
 497crc_err:
 498			stats = per_cpu_ptr(lport->dev_stats, get_cpu());
 499			stats->ErrorFrames++;
 500			/* per cpu count, not total count, but OK for limit */
 501			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
 502				printk(KERN_WARNING "libfc: CRC error on data "
 503				       "frame for port (%6.6x)\n",
 504				       lport->port_id);
 505			put_cpu();
 506			/*
 507			 * Assume the frame is total garbage.
 508			 * We may have copied it over the good part
 509			 * of the buffer.
 510			 * If so, we need to retry the entire operation.
 511			 * Otherwise, ignore it.
 512			 */
 513			if (fsp->state & FC_SRB_DISCONTIG) {
 514				host_bcode = FC_CRC_ERROR;
 515				goto err;
 516			}
 517			return;
 518		}
 519	}
 520
 521	if (fsp->xfer_contig_end == start_offset)
 522		fsp->xfer_contig_end += copy_len;
 523	fsp->xfer_len += copy_len;
 524
 525	/*
 526	 * In the very rare event that this data arrived after the response
 527	 * and completes the transfer, call the completion handler.
 528	 */
 529	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
 530	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
 531		fc_fcp_complete_locked(fsp);
 532	return;
 533err:
 534	fc_fcp_recovery(fsp, host_bcode);
 535}
 536
 537/**
 538 * fc_fcp_send_data() - Send SCSI data to a target
 539 * @fsp:      The FCP packet the data is on
 540 * @sp:	      The sequence the data is to be sent on
 541 * @offset:   The starting offset for this data request
 542 * @seq_blen: The burst length for this data request
 543 *
 544 * Called after receiving a Transfer Ready data descriptor.
 545 * If the LLD is capable of sequence offload then send down the
 546 * seq_blen amount of data in single frame, otherwise send
 547 * multiple frames of the maximum frame payload supported by
 548 * the target port.
 549 */
 550static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 551			    size_t offset, size_t seq_blen)
 552{
 553	struct fc_exch *ep;
 554	struct scsi_cmnd *sc;
 555	struct scatterlist *sg;
 556	struct fc_frame *fp = NULL;
 557	struct fc_lport *lport = fsp->lp;
 558	struct page *page;
 559	size_t remaining;
 560	size_t t_blen;
 561	size_t tlen;
 562	size_t sg_bytes;
 563	size_t frame_offset, fh_parm_offset;
 564	size_t off;
 565	int error;
 566	void *data = NULL;
 567	void *page_addr;
 568	int using_sg = lport->sg_supp;
 569	u32 f_ctl;
 570
 571	WARN_ON(seq_blen <= 0);
 572	if (unlikely(offset + seq_blen > fsp->data_len)) {
 573		/* this should never happen */
 574		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
 575			   "offset %zx\n", seq_blen, offset);
 576		fc_fcp_send_abort(fsp);
 577		return 0;
 578	} else if (offset != fsp->xfer_len) {
 579		/* Out of Order Data Request - no problem, but unexpected. */
 580		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
 581			   "seq_blen %zx offset %zx\n", seq_blen, offset);
 582	}
 583
 584	/*
 585	 * if LLD is capable of seq_offload then set transport
 586	 * burst length (t_blen) to seq_blen, otherwise set t_blen
 587	 * to max FC frame payload previously set in fsp->max_payload.
 588	 */
 589	t_blen = fsp->max_payload;
 590	if (lport->seq_offload) {
 591		t_blen = min(seq_blen, (size_t)lport->lso_max);
 592		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
 593			   fsp, seq_blen, lport->lso_max, t_blen);
 594	}
 595
 596	if (t_blen > 512)
 597		t_blen &= ~(512 - 1);	/* round down to block size */
 598	sc = fsp->cmd;
 599
 600	remaining = seq_blen;
 601	fh_parm_offset = frame_offset = offset;
 602	tlen = 0;
 603	seq = lport->tt.seq_start_next(seq);
 604	f_ctl = FC_FC_REL_OFF;
 605	WARN_ON(!seq);
 606
 607	sg = scsi_sglist(sc);
 608
 609	while (remaining > 0 && sg) {
 610		if (offset >= sg->length) {
 611			offset -= sg->length;
 612			sg = sg_next(sg);
 613			continue;
 614		}
 615		if (!fp) {
 616			tlen = min(t_blen, remaining);
 617
 618			/*
 619			 * TODO.  Temporary workaround.	 fc_seq_send() can't
 620			 * handle odd lengths in non-linear skbs.
 621			 * This will be the final fragment only.
 622			 */
 623			if (tlen % 4)
 624				using_sg = 0;
 625			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
 626			if (!fp)
 627				return -ENOMEM;
 628
 629			data = fc_frame_header_get(fp) + 1;
 630			fh_parm_offset = frame_offset;
 631			fr_max_payload(fp) = fsp->max_payload;
 632		}
 633
 634		off = offset + sg->offset;
 635		sg_bytes = min(tlen, sg->length - offset);
 636		sg_bytes = min(sg_bytes,
 637			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
 638		page = sg_page(sg) + (off >> PAGE_SHIFT);
 639		if (using_sg) {
 640			get_page(page);
 641			skb_fill_page_desc(fp_skb(fp),
 642					   skb_shinfo(fp_skb(fp))->nr_frags,
 643					   page, off & ~PAGE_MASK, sg_bytes);
 644			fp_skb(fp)->data_len += sg_bytes;
 645			fr_len(fp) += sg_bytes;
 646			fp_skb(fp)->truesize += PAGE_SIZE;
 647		} else {
 648			/*
 649			 * The scatterlist item may be bigger than PAGE_SIZE,
 650			 * but we must not cross pages inside the kmap.
 651			 */
 652			page_addr = kmap_atomic(page, KM_SOFTIRQ0);
 653			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
 654			       sg_bytes);
 655			kunmap_atomic(page_addr, KM_SOFTIRQ0);
 656			data += sg_bytes;
 657		}
 658		offset += sg_bytes;
 659		frame_offset += sg_bytes;
 660		tlen -= sg_bytes;
 661		remaining -= sg_bytes;
 662
 663		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
 664		    (tlen))
 665			continue;
 666
 667		/*
 668		 * Send sequence with transfer sequence initiative in case
 669		 * this is last FCP frame of the sequence.
 670		 */
 671		if (remaining == 0)
 672			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
 673
 674		ep = fc_seq_exch(seq);
 675		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 676			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
 677
 678		/*
 679		 * send fragment using for a sequence.
 680		 */
 681		error = lport->tt.seq_send(lport, seq, fp);
 682		if (error) {
 683			WARN_ON(1);		/* send error should be rare */
 684			return error;
 685		}
 686		fp = NULL;
 687	}
 688	fsp->xfer_len += seq_blen;	/* premature count? */
 689	return 0;
 690}
 691
 692/**
 693 * fc_fcp_abts_resp() - Receive an ABTS response
 694 * @fsp: The FCP packet that is being aborted
 695 * @fp:	 The response frame
 696 */
 697static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 698{
 699	int ba_done = 1;
 700	struct fc_ba_rjt *brp;
 701	struct fc_frame_header *fh;
 702
 703	fh = fc_frame_header_get(fp);
 704	switch (fh->fh_r_ctl) {
 705	case FC_RCTL_BA_ACC:
 706		break;
 707	case FC_RCTL_BA_RJT:
 708		brp = fc_frame_payload_get(fp, sizeof(*brp));
 709		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
 710			break;
 711		/* fall thru */
 712	default:
 713		/*
 714		 * we will let the command timeout
 715		 * and scsi-ml recover in this case,
 716		 * therefore cleared the ba_done flag.
 717		 */
 718		ba_done = 0;
 719	}
 720
 721	if (ba_done) {
 722		fsp->state |= FC_SRB_ABORTED;
 723		fsp->state &= ~FC_SRB_ABORT_PENDING;
 724
 725		if (fsp->wait_for_comp)
 726			complete(&fsp->tm_done);
 727		else
 728			fc_fcp_complete_locked(fsp);
 729	}
 730}
 731
 732/**
 733 * fc_fcp_recv() - Receive an FCP frame
 734 * @seq: The sequence the frame is on
 735 * @fp:	 The received frame
 736 * @arg: The related FCP packet
 737 *
 738 * Context: Called from Soft IRQ context. Can not be called
 739 *	    holding the FCP packet list lock.
 740 */
 741static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
 742{
 743	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
 744	struct fc_lport *lport = fsp->lp;
 745	struct fc_frame_header *fh;
 746	struct fcp_txrdy *dd;
 747	u8 r_ctl;
 748	int rc = 0;
 749
 750	if (IS_ERR(fp)) {
 751		fc_fcp_error(fsp, fp);
 752		return;
 753	}
 754
 755	fh = fc_frame_header_get(fp);
 756	r_ctl = fh->fh_r_ctl;
 757
 758	if (lport->state != LPORT_ST_READY)
 759		goto out;
 760	if (fc_fcp_lock_pkt(fsp))
 761		goto out;
 762	fsp->last_pkt_time = jiffies;
 763
 764	if (fh->fh_type == FC_TYPE_BLS) {
 765		fc_fcp_abts_resp(fsp, fp);
 766		goto unlock;
 767	}
 768
 769	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
 770		goto unlock;
 771
 772	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
 773		/*
 774		 * received XFER RDY from the target
 775		 * need to send data to the target
 776		 */
 777		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 778		dd = fc_frame_payload_get(fp, sizeof(*dd));
 779		WARN_ON(!dd);
 780
 781		rc = fc_fcp_send_data(fsp, seq,
 782				      (size_t) ntohl(dd->ft_data_ro),
 783				      (size_t) ntohl(dd->ft_burst_len));
 784		if (!rc)
 785			seq->rec_data = fsp->xfer_len;
 786	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
 787		/*
 788		 * received a DATA frame
 789		 * next we will copy the data to the system buffer
 790		 */
 791		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
 792		fc_fcp_recv_data(fsp, fp);
 793		seq->rec_data = fsp->xfer_contig_end;
 794	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
 795		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
 796
 797		fc_fcp_resp(fsp, fp);
 798	} else {
 799		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
 800	}
 801unlock:
 802	fc_fcp_unlock_pkt(fsp);
 803out:
 804	fc_frame_free(fp);
 805}
 806
 807/**
 808 * fc_fcp_resp() - Handler for FCP responses
 809 * @fsp: The FCP packet the response is for
 810 * @fp:	 The response frame
 811 */
 812static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 813{
 814	struct fc_frame_header *fh;
 815	struct fcp_resp *fc_rp;
 816	struct fcp_resp_ext *rp_ex;
 817	struct fcp_resp_rsp_info *fc_rp_info;
 818	u32 plen;
 819	u32 expected_len;
 820	u32 respl = 0;
 821	u32 snsl = 0;
 822	u8 flags = 0;
 823
 824	plen = fr_len(fp);
 825	fh = (struct fc_frame_header *)fr_hdr(fp);
 826	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
 827		goto len_err;
 828	plen -= sizeof(*fh);
 829	fc_rp = (struct fcp_resp *)(fh + 1);
 830	fsp->cdb_status = fc_rp->fr_status;
 831	flags = fc_rp->fr_flags;
 832	fsp->scsi_comp_flags = flags;
 833	expected_len = fsp->data_len;
 834
 835	/* if ddp, update xfer len */
 836	fc_fcp_ddp_done(fsp);
 837
 838	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
 839		rp_ex = (void *)(fc_rp + 1);
 840		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
 841			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
 842				goto len_err;
 843			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
 844			if (flags & FCP_RSP_LEN_VAL) {
 845				respl = ntohl(rp_ex->fr_rsp_len);
 846				if (respl != sizeof(*fc_rp_info))
 847					goto len_err;
 848				if (fsp->wait_for_comp) {
 849					/* Abuse cdb_status for rsp code */
 850					fsp->cdb_status = fc_rp_info->rsp_code;
 851					complete(&fsp->tm_done);
 852					/*
 853					 * tmfs will not have any scsi cmd so
 854					 * exit here
 855					 */
 856					return;
 857				}
 858			}
 859			if (flags & FCP_SNS_LEN_VAL) {
 860				snsl = ntohl(rp_ex->fr_sns_len);
 861				if (snsl > SCSI_SENSE_BUFFERSIZE)
 862					snsl = SCSI_SENSE_BUFFERSIZE;
 863				memcpy(fsp->cmd->sense_buffer,
 864				       (char *)fc_rp_info + respl, snsl);
 865			}
 866		}
 867		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
 868			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
 869				goto len_err;
 870			if (flags & FCP_RESID_UNDER) {
 871				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
 872				/*
 873				 * The cmnd->underflow is the minimum number of
 874				 * bytes that must be transferred for this
 875				 * command.  Provided a sense condition is not
 876				 * present, make sure the actual amount
 877				 * transferred is at least the underflow value
 878				 * or fail.
 879				 */
 880				if (!(flags & FCP_SNS_LEN_VAL) &&
 881				    (fc_rp->fr_status == 0) &&
 882				    (scsi_bufflen(fsp->cmd) -
 883				     fsp->scsi_resid) < fsp->cmd->underflow)
 884					goto err;
 885				expected_len -= fsp->scsi_resid;
 886			} else {
 887				fsp->status_code = FC_ERROR;
 888			}
 889		}
 890	}
 891	fsp->state |= FC_SRB_RCV_STATUS;
 892
 893	/*
 894	 * Check for missing or extra data frames.
 895	 */
 896	if (unlikely(fsp->xfer_len != expected_len)) {
 897		if (fsp->xfer_len < expected_len) {
 898			/*
 899			 * Some data may be queued locally,
 900			 * Wait a at least one jiffy to see if it is delivered.
 901			 * If this expires without data, we may do SRR.
 902			 */
 903			fc_fcp_timer_set(fsp, 2);
 904			return;
 905		}
 906		fsp->status_code = FC_DATA_OVRRUN;
 907		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
 908			   "len %x, data len %x\n",
 909			   fsp->rport->port_id,
 910			   fsp->xfer_len, expected_len, fsp->data_len);
 911	}
 912	fc_fcp_complete_locked(fsp);
 913	return;
 914
 915len_err:
 916	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
 917		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
 918err:
 919	fsp->status_code = FC_ERROR;
 920	fc_fcp_complete_locked(fsp);
 921}
 922
 923/**
 924 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
 925 *			      fcp_pkt lock held
 926 * @fsp: The FCP packet to be completed
 927 *
 928 * This function may sleep if a timer is pending. The packet lock must be
 929 * held, and the host lock must not be held.
 930 */
 931static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 932{
 933	struct fc_lport *lport = fsp->lp;
 934	struct fc_seq *seq;
 935	struct fc_exch *ep;
 936	u32 f_ctl;
 937
 938	if (fsp->state & FC_SRB_ABORT_PENDING)
 939		return;
 940
 941	if (fsp->state & FC_SRB_ABORTED) {
 942		if (!fsp->status_code)
 943			fsp->status_code = FC_CMD_ABORTED;
 944	} else {
 945		/*
 946		 * Test for transport underrun, independent of response
 947		 * underrun status.
 948		 */
 949		if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
 950		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
 951		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
 952			fsp->status_code = FC_DATA_UNDRUN;
 953			fsp->io_status = 0;
 954		}
 955	}
 956
 957	seq = fsp->seq_ptr;
 958	if (seq) {
 959		fsp->seq_ptr = NULL;
 960		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
 961			struct fc_frame *conf_frame;
 962			struct fc_seq *csp;
 963
 964			csp = lport->tt.seq_start_next(seq);
 965			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
 966			if (conf_frame) {
 967				f_ctl = FC_FC_SEQ_INIT;
 968				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
 969				ep = fc_seq_exch(seq);
 970				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
 971					       ep->did, ep->sid,
 972					       FC_TYPE_FCP, f_ctl, 0);
 973				lport->tt.seq_send(lport, csp, conf_frame);
 974			}
 975		}
 976		lport->tt.exch_done(seq);
 977	}
 978	/*
 979	 * Some resets driven by SCSI are not I/Os and do not have
 980	 * SCSI commands associated with the requests. We should not
 981	 * call I/O completion if we do not have a SCSI command.
 982	 */
 983	if (fsp->cmd)
 984		fc_io_compl(fsp);
 985}
 986
 987/**
 988 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
 989 * @fsp:   The FCP packet whose exchanges should be canceled
 990 * @error: The reason for the cancellation
 991 */
 992static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
 993{
 994	struct fc_lport *lport = fsp->lp;
 995
 996	if (fsp->seq_ptr) {
 997		lport->tt.exch_done(fsp->seq_ptr);
 998		fsp->seq_ptr = NULL;
 999	}
1000	fsp->status_code = error;
1001}
1002
1003/**
1004 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1005 * @lport: The local port whose exchanges should be canceled
1006 * @id:	   The target's ID
1007 * @lun:   The LUN
1008 * @error: The reason for cancellation
1009 *
1010 * If lun or id is -1, they are ignored.
1011 */
1012static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1013				    unsigned int lun, int error)
1014{
1015	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1016	struct fc_fcp_pkt *fsp;
1017	struct scsi_cmnd *sc_cmd;
1018	unsigned long flags;
1019
1020	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1021restart:
1022	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1023		sc_cmd = fsp->cmd;
1024		if (id != -1 && scmd_id(sc_cmd) != id)
1025			continue;
1026
1027		if (lun != -1 && sc_cmd->device->lun != lun)
1028			continue;
1029
1030		fc_fcp_pkt_hold(fsp);
1031		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1032
1033		if (!fc_fcp_lock_pkt(fsp)) {
1034			fc_fcp_cleanup_cmd(fsp, error);
1035			fc_io_compl(fsp);
1036			fc_fcp_unlock_pkt(fsp);
1037		}
1038
1039		fc_fcp_pkt_release(fsp);
1040		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1041		/*
1042		 * while we dropped the lock multiple pkts could
1043		 * have been released, so we have to start over.
1044		 */
1045		goto restart;
1046	}
1047	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1048}
1049
1050/**
1051 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1052 * @lport: The local port whose exchanges are to be aborted
1053 */
1054static void fc_fcp_abort_io(struct fc_lport *lport)
1055{
1056	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1057}
1058
1059/**
1060 * fc_fcp_pkt_send() - Send a fcp_pkt
1061 * @lport: The local port to send the FCP packet on
1062 * @fsp:   The FCP packet to send
1063 *
1064 * Return:  Zero for success and -1 for failure
1065 * Locks:   Called without locks held
1066 */
1067static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1068{
1069	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1070	unsigned long flags;
1071	int rc;
1072
1073	fsp->cmd->SCp.ptr = (char *)fsp;
1074	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1075	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1076
1077	int_to_scsilun(fsp->cmd->device->lun,
1078		       (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1079	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1080
1081	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1082	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1083	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1084	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1085	if (unlikely(rc)) {
1086		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1087		fsp->cmd->SCp.ptr = NULL;
1088		list_del(&fsp->list);
1089		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1090	}
1091
1092	return rc;
1093}
1094
1095/**
1096 * get_fsp_rec_tov() - Helper function to get REC_TOV
1097 * @fsp: the FCP packet
1098 *
1099 * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
1100 */
1101static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
1102{
1103	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
1104
1105	return msecs_to_jiffies(rpriv->e_d_tov) + HZ;
1106}
1107
1108/**
1109 * fc_fcp_cmd_send() - Send a FCP command
1110 * @lport: The local port to send the command on
1111 * @fsp:   The FCP packet the command is on
1112 * @resp:  The handler for the response
1113 */
1114static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1115			   void (*resp)(struct fc_seq *,
1116					struct fc_frame *fp,
1117					void *arg))
1118{
1119	struct fc_frame *fp;
1120	struct fc_seq *seq;
1121	struct fc_rport *rport;
1122	struct fc_rport_libfc_priv *rpriv;
1123	const size_t len = sizeof(fsp->cdb_cmd);
1124	int rc = 0;
1125
1126	if (fc_fcp_lock_pkt(fsp))
1127		return 0;
1128
1129	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1130	if (!fp) {
1131		rc = -1;
1132		goto unlock;
1133	}
1134
1135	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1136	fr_fsp(fp) = fsp;
1137	rport = fsp->rport;
1138	fsp->max_payload = rport->maxframe_size;
1139	rpriv = rport->dd_data;
1140
1141	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1142		       rpriv->local_port->port_id, FC_TYPE_FCP,
1143		       FC_FCTL_REQ, 0);
1144
1145	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
1146				      fsp, 0);
1147	if (!seq) {
1148		rc = -1;
1149		goto unlock;
1150	}
1151	fsp->last_pkt_time = jiffies;
1152	fsp->seq_ptr = seq;
1153	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1154
1155	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1156	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1157		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1158
1159unlock:
1160	fc_fcp_unlock_pkt(fsp);
1161	return rc;
1162}
1163
1164/**
1165 * fc_fcp_error() - Handler for FCP layer errors
1166 * @fsp: The FCP packet the error is on
1167 * @fp:	 The frame that has errored
1168 */
1169static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1170{
1171	int error = PTR_ERR(fp);
1172
1173	if (fc_fcp_lock_pkt(fsp))
1174		return;
1175
1176	if (error == -FC_EX_CLOSED) {
1177		fc_fcp_retry_cmd(fsp);
1178		goto unlock;
1179	}
1180
1181	/*
1182	 * clear abort pending, because the lower layer
1183	 * decided to force completion.
1184	 */
1185	fsp->state &= ~FC_SRB_ABORT_PENDING;
1186	fsp->status_code = FC_CMD_PLOGO;
1187	fc_fcp_complete_locked(fsp);
1188unlock:
1189	fc_fcp_unlock_pkt(fsp);
1190}
1191
1192/**
1193 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1194 * @fsp:   The FCP packet to abort on
1195 *
1196 * Called to send an abort and then wait for abort completion
1197 */
1198static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1199{
1200	int rc = FAILED;
1201	unsigned long ticks_left;
1202
1203	if (fc_fcp_send_abort(fsp))
1204		return FAILED;
1205
1206	init_completion(&fsp->tm_done);
1207	fsp->wait_for_comp = 1;
1208
1209	spin_unlock_bh(&fsp->scsi_pkt_lock);
1210	ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1211							FC_SCSI_TM_TOV);
1212	spin_lock_bh(&fsp->scsi_pkt_lock);
1213	fsp->wait_for_comp = 0;
1214
1215	if (!ticks_left) {
1216		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1217	} else if (fsp->state & FC_SRB_ABORTED) {
1218		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1219		rc = SUCCESS;
1220		fc_fcp_complete_locked(fsp);
1221	}
1222
1223	return rc;
1224}
1225
1226/**
1227 * fc_lun_reset_send() - Send LUN reset command
1228 * @data: The FCP packet that identifies the LUN to be reset
1229 */
1230static void fc_lun_reset_send(unsigned long data)
1231{
1232	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1233	struct fc_lport *lport = fsp->lp;
1234
1235	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1236		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1237			return;
1238		if (fc_fcp_lock_pkt(fsp))
1239			return;
1240		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1241		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1242		fc_fcp_unlock_pkt(fsp);
1243	}
1244}
1245
1246/**
1247 * fc_lun_reset() - Send a LUN RESET command to a device
1248 *		    and wait for the reply
1249 * @lport: The local port to sent the command on
1250 * @fsp:   The FCP packet that identifies the LUN to be reset
1251 * @id:	   The SCSI command ID
1252 * @lun:   The LUN ID to be reset
1253 */
1254static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1255			unsigned int id, unsigned int lun)
1256{
1257	int rc;
1258
1259	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1260	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1261	int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1262
1263	fsp->wait_for_comp = 1;
1264	init_completion(&fsp->tm_done);
1265
1266	fc_lun_reset_send((unsigned long)fsp);
1267
1268	/*
1269	 * wait for completion of reset
1270	 * after that make sure all commands are terminated
1271	 */
1272	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1273
1274	spin_lock_bh(&fsp->scsi_pkt_lock);
1275	fsp->state |= FC_SRB_COMPL;
1276	spin_unlock_bh(&fsp->scsi_pkt_lock);
1277
1278	del_timer_sync(&fsp->timer);
1279
1280	spin_lock_bh(&fsp->scsi_pkt_lock);
1281	if (fsp->seq_ptr) {
1282		lport->tt.exch_done(fsp->seq_ptr);
1283		fsp->seq_ptr = NULL;
1284	}
1285	fsp->wait_for_comp = 0;
1286	spin_unlock_bh(&fsp->scsi_pkt_lock);
1287
1288	if (!rc) {
1289		FC_SCSI_DBG(lport, "lun reset failed\n");
1290		return FAILED;
1291	}
1292
1293	/* cdb_status holds the tmf's rsp code */
1294	if (fsp->cdb_status != FCP_TMF_CMPL)
1295		return FAILED;
1296
1297	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1298	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1299	return SUCCESS;
1300}
1301
1302/**
1303 * fc_tm_done() - Task Management response handler
1304 * @seq: The sequence that the response is on
1305 * @fp:	 The response frame
1306 * @arg: The FCP packet the response is for
1307 */
1308static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1309{
1310	struct fc_fcp_pkt *fsp = arg;
1311	struct fc_frame_header *fh;
1312
1313	if (IS_ERR(fp)) {
1314		/*
1315		 * If there is an error just let it timeout or wait
1316		 * for TMF to be aborted if it timedout.
1317		 *
1318		 * scsi-eh will escalate for when either happens.
1319		 */
1320		return;
1321	}
1322
1323	if (fc_fcp_lock_pkt(fsp))
1324		goto out;
1325
1326	/*
1327	 * raced with eh timeout handler.
1328	 */
1329	if (!fsp->seq_ptr || !fsp->wait_for_comp)
1330		goto out_unlock;
1331
1332	fh = fc_frame_header_get(fp);
1333	if (fh->fh_type != FC_TYPE_BLS)
1334		fc_fcp_resp(fsp, fp);
1335	fsp->seq_ptr = NULL;
1336	fsp->lp->tt.exch_done(seq);
1337out_unlock:
1338	fc_fcp_unlock_pkt(fsp);
1339out:
1340	fc_frame_free(fp);
1341}
1342
1343/**
1344 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1345 * @lport: The local port to be cleaned up
1346 */
1347static void fc_fcp_cleanup(struct fc_lport *lport)
1348{
1349	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1350}
1351
1352/**
1353 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1354 * @data: The FCP packet that has timed out
1355 *
1356 * If REC is supported then just issue it and return. The REC exchange will
1357 * complete or time out and recovery can continue at that point. Otherwise,
1358 * if the response has been received without all the data it has been
1359 * ER_TIMEOUT since the response was received. If the response has not been
1360 * received we see if data was received recently. If it has been then we
1361 * continue waiting, otherwise, we abort the command.
1362 */
1363static void fc_fcp_timeout(unsigned long data)
1364{
1365	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1366	struct fc_rport *rport = fsp->rport;
1367	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1368
1369	if (fc_fcp_lock_pkt(fsp))
1370		return;
1371
1372	if (fsp->cdb_cmd.fc_tm_flags)
1373		goto unlock;
1374
1375	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1376
1377	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1378		fc_fcp_rec(fsp);
1379	else if (fsp->state & FC_SRB_RCV_STATUS)
1380		fc_fcp_complete_locked(fsp);
1381	else
1382		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1383	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1384unlock:
1385	fc_fcp_unlock_pkt(fsp);
1386}
1387
1388/**
1389 * fc_fcp_rec() - Send a REC ELS request
1390 * @fsp: The FCP packet to send the REC request on
1391 */
1392static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1393{
1394	struct fc_lport *lport;
1395	struct fc_frame *fp;
1396	struct fc_rport *rport;
1397	struct fc_rport_libfc_priv *rpriv;
1398
1399	lport = fsp->lp;
1400	rport = fsp->rport;
1401	rpriv = rport->dd_data;
1402	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1403		fsp->status_code = FC_HRD_ERROR;
1404		fsp->io_status = 0;
1405		fc_fcp_complete_locked(fsp);
1406		return;
1407	}
1408
1409	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1410	if (!fp)
1411		goto retry;
1412
1413	fr_seq(fp) = fsp->seq_ptr;
1414	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1415		       rpriv->local_port->port_id, FC_TYPE_ELS,
1416		       FC_FCTL_REQ, 0);
1417	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1418				 fc_fcp_rec_resp, fsp,
1419				 2 * lport->r_a_tov)) {
1420		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1421		return;
1422	}
1423retry:
1424	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1425		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1426	else
1427		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1428}
1429
1430/**
1431 * fc_fcp_rec_resp() - Handler for REC ELS responses
1432 * @seq: The sequence the response is on
1433 * @fp:	 The response frame
1434 * @arg: The FCP packet the response is on
1435 *
1436 * If the response is a reject then the scsi layer will handle
1437 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1438 * set the timeout and return. If the I/O was completed then complete the
1439 * exchange and tell the SCSI layer.
1440 */
1441static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1442{
1443	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1444	struct fc_els_rec_acc *recp;
1445	struct fc_els_ls_rjt *rjt;
1446	u32 e_stat;
1447	u8 opcode;
1448	u32 offset;
1449	enum dma_data_direction data_dir;
1450	enum fc_rctl r_ctl;
1451	struct fc_rport_libfc_priv *rpriv;
1452
1453	if (IS_ERR(fp)) {
1454		fc_fcp_rec_error(fsp, fp);
1455		return;
1456	}
1457
1458	if (fc_fcp_lock_pkt(fsp))
1459		goto out;
1460
1461	fsp->recov_retry = 0;
1462	opcode = fc_frame_payload_op(fp);
1463	if (opcode == ELS_LS_RJT) {
1464		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1465		switch (rjt->er_reason) {
1466		default:
1467			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1468				   "reason %d expl %d\n",
1469				   fsp->rport->port_id, rjt->er_reason,
1470				   rjt->er_explan);
1471			/* fall through */
1472		case ELS_RJT_UNSUP:
1473			FC_FCP_DBG(fsp, "device does not support REC\n");
1474			rpriv = fsp->rport->dd_data;
1475			/*
1476			 * if we do not spport RECs or got some bogus
1477			 * reason then resetup timer so we check for
1478			 * making progress.
1479			 */
1480			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1481			break;
1482		case ELS_RJT_LOGIC:
1483		case ELS_RJT_UNAB:
1484			/*
1485			 * If no data transfer, the command frame got dropped
1486			 * so we just retry.  If data was transferred, we
1487			 * lost the response but the target has no record,
1488			 * so we abort and retry.
1489			 */
1490			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1491			    fsp->xfer_len == 0) {
1492				fc_fcp_retry_cmd(fsp);
1493				break;
1494			}
1495			fc_fcp_recovery(fsp, FC_ERROR);
1496			break;
1497		}
1498	} else if (opcode == ELS_LS_ACC) {
1499		if (fsp->state & FC_SRB_ABORTED)
1500			goto unlock_out;
1501
1502		data_dir = fsp->cmd->sc_data_direction;
1503		recp = fc_frame_payload_get(fp, sizeof(*recp));
1504		offset = ntohl(recp->reca_fc4value);
1505		e_stat = ntohl(recp->reca_e_stat);
1506
1507		if (e_stat & ESB_ST_COMPLETE) {
1508
1509			/*
1510			 * The exchange is complete.
1511			 *
1512			 * For output, we must've lost the response.
1513			 * For input, all data must've been sent.
1514			 * We lost may have lost the response
1515			 * (and a confirmation was requested) and maybe
1516			 * some data.
1517			 *
1518			 * If all data received, send SRR
1519			 * asking for response.	 If partial data received,
1520			 * or gaps, SRR requests data at start of gap.
1521			 * Recovery via SRR relies on in-order-delivery.
1522			 */
1523			if (data_dir == DMA_TO_DEVICE) {
1524				r_ctl = FC_RCTL_DD_CMD_STATUS;
1525			} else if (fsp->xfer_contig_end == offset) {
1526				r_ctl = FC_RCTL_DD_CMD_STATUS;
1527			} else {
1528				offset = fsp->xfer_contig_end;
1529				r_ctl = FC_RCTL_DD_SOL_DATA;
1530			}
1531			fc_fcp_srr(fsp, r_ctl, offset);
1532		} else if (e_stat & ESB_ST_SEQ_INIT) {
1533			/*
1534			 * The remote port has the initiative, so just
1535			 * keep waiting for it to complete.
1536			 */
1537			fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1538		} else {
1539
1540			/*
1541			 * The exchange is incomplete, we have seq. initiative.
1542			 * Lost response with requested confirmation,
1543			 * lost confirmation, lost transfer ready or
1544			 * lost write data.
1545			 *
1546			 * For output, if not all data was received, ask
1547			 * for transfer ready to be repeated.
1548			 *
1549			 * If we received or sent all the data, send SRR to
1550			 * request response.
1551			 *
1552			 * If we lost a response, we may have lost some read
1553			 * data as well.
1554			 */
1555			r_ctl = FC_RCTL_DD_SOL_DATA;
1556			if (data_dir == DMA_TO_DEVICE) {
1557				r_ctl = FC_RCTL_DD_CMD_STATUS;
1558				if (offset < fsp->data_len)
1559					r_ctl = FC_RCTL_DD_DATA_DESC;
1560			} else if (offset == fsp->xfer_contig_end) {
1561				r_ctl = FC_RCTL_DD_CMD_STATUS;
1562			} else if (fsp->xfer_contig_end < offset) {
1563				offset = fsp->xfer_contig_end;
1564			}
1565			fc_fcp_srr(fsp, r_ctl, offset);
1566		}
1567	}
1568unlock_out:
1569	fc_fcp_unlock_pkt(fsp);
1570out:
1571	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1572	fc_frame_free(fp);
1573}
1574
1575/**
1576 * fc_fcp_rec_error() - Handler for REC errors
1577 * @fsp: The FCP packet the error is on
1578 * @fp:	 The REC frame
1579 */
1580static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1581{
1582	int error = PTR_ERR(fp);
1583
1584	if (fc_fcp_lock_pkt(fsp))
1585		goto out;
1586
1587	switch (error) {
1588	case -FC_EX_CLOSED:
1589		fc_fcp_retry_cmd(fsp);
1590		break;
1591
1592	default:
1593		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1594			   fsp, fsp->rport->port_id, error);
1595		fsp->status_code = FC_CMD_PLOGO;
1596		/* fall through */
1597
1598	case -FC_EX_TIMEOUT:
1599		/*
1600		 * Assume REC or LS_ACC was lost.
1601		 * The exchange manager will have aborted REC, so retry.
1602		 */
1603		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
1604			   fsp->rport->port_id, error, fsp->recov_retry,
1605			   FC_MAX_RECOV_RETRY);
1606		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1607			fc_fcp_rec(fsp);
1608		else
1609			fc_fcp_recovery(fsp, FC_ERROR);
1610		break;
1611	}
1612	fc_fcp_unlock_pkt(fsp);
1613out:
1614	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1615}
1616
1617/**
1618 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1619 * @fsp: The FCP pkt that needs to be aborted
1620 */
1621static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1622{
1623	fsp->status_code = code;
1624	fsp->cdb_status = 0;
1625	fsp->io_status = 0;
1626	/*
1627	 * if this fails then we let the scsi command timer fire and
1628	 * scsi-ml escalate.
1629	 */
1630	fc_fcp_send_abort(fsp);
1631}
1632
1633/**
1634 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1635 * @fsp:   The FCP packet the SRR is to be sent on
1636 * @r_ctl: The R_CTL field for the SRR request
1637 * This is called after receiving status but insufficient data, or
1638 * when expecting status but the request has timed out.
1639 */
1640static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1641{
1642	struct fc_lport *lport = fsp->lp;
1643	struct fc_rport *rport;
1644	struct fc_rport_libfc_priv *rpriv;
1645	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1646	struct fc_seq *seq;
1647	struct fcp_srr *srr;
1648	struct fc_frame *fp;
1649	unsigned int rec_tov;
1650
1651	rport = fsp->rport;
1652	rpriv = rport->dd_data;
1653
1654	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1655	    rpriv->rp_state != RPORT_ST_READY)
1656		goto retry;			/* shouldn't happen */
1657	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1658	if (!fp)
1659		goto retry;
1660
1661	srr = fc_frame_payload_get(fp, sizeof(*srr));
1662	memset(srr, 0, sizeof(*srr));
1663	srr->srr_op = ELS_SRR;
1664	srr->srr_ox_id = htons(ep->oxid);
1665	srr->srr_rx_id = htons(ep->rxid);
1666	srr->srr_r_ctl = r_ctl;
1667	srr->srr_rel_off = htonl(offset);
1668
1669	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1670		       rpriv->local_port->port_id, FC_TYPE_FCP,
1671		       FC_FCTL_REQ, 0);
1672
1673	rec_tov = get_fsp_rec_tov(fsp);
1674	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp,
1675				      fc_fcp_pkt_destroy,
1676				      fsp, jiffies_to_msecs(rec_tov));
1677	if (!seq)
1678		goto retry;
1679
1680	fsp->recov_seq = seq;
1681	fsp->xfer_len = offset;
1682	fsp->xfer_contig_end = offset;
1683	fsp->state &= ~FC_SRB_RCV_STATUS;
1684	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1685	return;
1686retry:
1687	fc_fcp_retry_cmd(fsp);
1688}
1689
1690/**
1691 * fc_fcp_srr_resp() - Handler for SRR response
1692 * @seq: The sequence the SRR is on
1693 * @fp:	 The SRR frame
1694 * @arg: The FCP packet the SRR is on
1695 */
1696static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1697{
1698	struct fc_fcp_pkt *fsp = arg;
1699	struct fc_frame_header *fh;
1700
1701	if (IS_ERR(fp)) {
1702		fc_fcp_srr_error(fsp, fp);
1703		return;
1704	}
1705
1706	if (fc_fcp_lock_pkt(fsp))
1707		goto out;
1708
1709	fh = fc_frame_header_get(fp);
1710	/*
1711	 * BUG? fc_fcp_srr_error calls exch_done which would release
1712	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1713	 * then fc_exch_timeout would be sending an abort. The exch_done
1714	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1715	 * an abort response though.
1716	 */
1717	if (fh->fh_type == FC_TYPE_BLS) {
1718		fc_fcp_unlock_pkt(fsp);
1719		return;
1720	}
1721
1722	switch (fc_frame_payload_op(fp)) {
1723	case ELS_LS_ACC:
1724		fsp->recov_retry = 0;
1725		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1726		break;
1727	case ELS_LS_RJT:
1728	default:
1729		fc_fcp_recovery(fsp, FC_ERROR);
1730		break;
1731	}
1732	fc_fcp_unlock_pkt(fsp);
1733out:
1734	fsp->lp->tt.exch_done(seq);
1735	fc_frame_free(fp);
1736}
1737
1738/**
1739 * fc_fcp_srr_error() - Handler for SRR errors
1740 * @fsp: The FCP packet that the SRR error is on
1741 * @fp:	 The SRR frame
1742 */
1743static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1744{
1745	if (fc_fcp_lock_pkt(fsp))
1746		goto out;
1747	switch (PTR_ERR(fp)) {
1748	case -FC_EX_TIMEOUT:
1749		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1750			fc_fcp_rec(fsp);
1751		else
1752			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1753		break;
1754	case -FC_EX_CLOSED:			/* e.g., link failure */
1755		/* fall through */
1756	default:
1757		fc_fcp_retry_cmd(fsp);
1758		break;
1759	}
1760	fc_fcp_unlock_pkt(fsp);
1761out:
1762	fsp->lp->tt.exch_done(fsp->recov_seq);
1763}
1764
1765/**
1766 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1767 * @lport: The local port to be checked
1768 */
1769static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1770{
1771	/* lock ? */
1772	return (lport->state == LPORT_ST_READY) &&
1773		lport->link_up && !lport->qfull;
1774}
1775
1776/**
1777 * fc_queuecommand() - The queuecommand function of the SCSI template
1778 * @shost: The Scsi_Host that the command was issued to
1779 * @cmd:   The scsi_cmnd to be executed
1780 *
1781 * This is the i/o strategy routine, called by the SCSI layer.
1782 */
1783int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1784{
1785	struct fc_lport *lport = shost_priv(shost);
1786	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1787	struct fc_fcp_pkt *fsp;
1788	struct fc_rport_libfc_priv *rpriv;
1789	int rval;
1790	int rc = 0;
1791	struct fcoe_dev_stats *stats;
1792
1793	rval = fc_remote_port_chkready(rport);
1794	if (rval) {
1795		sc_cmd->result = rval;
1796		sc_cmd->scsi_done(sc_cmd);
1797		return 0;
1798	}
1799
1800	if (!*(struct fc_remote_port **)rport->dd_data) {
1801		/*
1802		 * rport is transitioning from blocked/deleted to
1803		 * online
1804		 */
1805		sc_cmd->result = DID_IMM_RETRY << 16;
1806		sc_cmd->scsi_done(sc_cmd);
1807		goto out;
1808	}
1809
1810	rpriv = rport->dd_data;
1811
1812	if (!fc_fcp_lport_queue_ready(lport)) {
1813		if (lport->qfull)
1814			fc_fcp_can_queue_ramp_down(lport);
1815		rc = SCSI_MLQUEUE_HOST_BUSY;
1816		goto out;
1817	}
1818
1819	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1820	if (fsp == NULL) {
1821		rc = SCSI_MLQUEUE_HOST_BUSY;
1822		goto out;
1823	}
1824
1825	/*
1826	 * build the libfc request pkt
1827	 */
1828	fsp->cmd = sc_cmd;	/* save the cmd */
1829	fsp->rport = rport;	/* set the remote port ptr */
1830
1831	/*
1832	 * set up the transfer length
1833	 */
1834	fsp->data_len = scsi_bufflen(sc_cmd);
1835	fsp->xfer_len = 0;
1836
1837	/*
1838	 * setup the data direction
1839	 */
1840	stats = per_cpu_ptr(lport->dev_stats, get_cpu());
1841	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1842		fsp->req_flags = FC_SRB_READ;
1843		stats->InputRequests++;
1844		stats->InputBytes += fsp->data_len;
1845	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1846		fsp->req_flags = FC_SRB_WRITE;
1847		stats->OutputRequests++;
1848		stats->OutputBytes += fsp->data_len;
1849	} else {
1850		fsp->req_flags = 0;
1851		stats->ControlRequests++;
1852	}
1853	put_cpu();
1854
1855	init_timer(&fsp->timer);
1856	fsp->timer.data = (unsigned long)fsp;
1857
1858	/*
1859	 * send it to the lower layer
1860	 * if we get -1 return then put the request in the pending
1861	 * queue.
1862	 */
1863	rval = fc_fcp_pkt_send(lport, fsp);
1864	if (rval != 0) {
1865		fsp->state = FC_SRB_FREE;
1866		fc_fcp_pkt_release(fsp);
1867		rc = SCSI_MLQUEUE_HOST_BUSY;
1868	}
1869out:
1870	return rc;
1871}
1872EXPORT_SYMBOL(fc_queuecommand);
1873
1874/**
1875 * fc_io_compl() - Handle responses for completed commands
1876 * @fsp: The FCP packet that is complete
1877 *
1878 * Translates fcp_pkt errors to a Linux SCSI errors.
1879 * The fcp packet lock must be held when calling.
1880 */
1881static void fc_io_compl(struct fc_fcp_pkt *fsp)
1882{
1883	struct fc_fcp_internal *si;
1884	struct scsi_cmnd *sc_cmd;
1885	struct fc_lport *lport;
1886	unsigned long flags;
1887
1888	/* release outstanding ddp context */
1889	fc_fcp_ddp_done(fsp);
1890
1891	fsp->state |= FC_SRB_COMPL;
1892	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1893		spin_unlock_bh(&fsp->scsi_pkt_lock);
1894		del_timer_sync(&fsp->timer);
1895		spin_lock_bh(&fsp->scsi_pkt_lock);
1896	}
1897
1898	lport = fsp->lp;
1899	si = fc_get_scsi_internal(lport);
1900
1901	/*
1902	 * if can_queue ramp down is done then try can_queue ramp up
1903	 * since commands are completing now.
1904	 */
1905	if (si->last_can_queue_ramp_down_time)
1906		fc_fcp_can_queue_ramp_up(lport);
1907
1908	sc_cmd = fsp->cmd;
1909	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1910	switch (fsp->status_code) {
1911	case FC_COMPLETE:
1912		if (fsp->cdb_status == 0) {
1913			/*
1914			 * good I/O status
1915			 */
1916			sc_cmd->result = DID_OK << 16;
1917			if (fsp->scsi_resid)
1918				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1919		} else {
1920			/*
1921			 * transport level I/O was ok but scsi
1922			 * has non zero status
1923			 */
1924			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1925		}
1926		break;
1927	case FC_ERROR:
1928		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1929			   "due to FC_ERROR\n");
1930		sc_cmd->result = DID_ERROR << 16;
1931		break;
1932	case FC_DATA_UNDRUN:
1933		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1934			/*
1935			 * scsi status is good but transport level
1936			 * underrun.
1937			 */
1938			if (fsp->state & FC_SRB_RCV_STATUS) {
1939				sc_cmd->result = DID_OK << 16;
1940			} else {
1941				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
1942					   " due to FC_DATA_UNDRUN (trans)\n");
1943				sc_cmd->result = DID_ERROR << 16;
1944			}
1945		} else {
1946			/*
1947			 * scsi got underrun, this is an error
1948			 */
1949			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1950				   "due to FC_DATA_UNDRUN (scsi)\n");
1951			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1952			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1953		}
1954		break;
1955	case FC_DATA_OVRRUN:
1956		/*
1957		 * overrun is an error
1958		 */
1959		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1960			   "due to FC_DATA_OVRRUN\n");
1961		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1962		break;
1963	case FC_CMD_ABORTED:
1964		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1965			  "due to FC_CMD_ABORTED\n");
1966		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1967		break;
1968	case FC_CMD_RESET:
1969		FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
1970			   "due to FC_CMD_RESET\n");
1971		sc_cmd->result = (DID_RESET << 16);
1972		break;
1973	case FC_HRD_ERROR:
1974		FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
1975			   "due to FC_HRD_ERROR\n");
1976		sc_cmd->result = (DID_NO_CONNECT << 16);
1977		break;
1978	case FC_CRC_ERROR:
1979		FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
1980			   "due to FC_CRC_ERROR\n");
1981		sc_cmd->result = (DID_PARITY << 16);
1982		break;
1983	case FC_TIMED_OUT:
1984		FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
1985			   "due to FC_TIMED_OUT\n");
1986		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1987		break;
1988	default:
1989		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1990			   "due to unknown error\n");
1991		sc_cmd->result = (DID_ERROR << 16);
1992		break;
1993	}
1994
1995	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
1996		sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
1997
1998	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1999	list_del(&fsp->list);
2000	sc_cmd->SCp.ptr = NULL;
2001	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2002	sc_cmd->scsi_done(sc_cmd);
2003
2004	/* release ref from initial allocation in queue command */
2005	fc_fcp_pkt_release(fsp);
2006}
2007
2008/**
2009 * fc_eh_abort() - Abort a command
2010 * @sc_cmd: The SCSI command to abort
2011 *
2012 * From SCSI host template.
2013 * Send an ABTS to the target device and wait for the response.
2014 */
2015int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2016{
2017	struct fc_fcp_pkt *fsp;
2018	struct fc_lport *lport;
2019	struct fc_fcp_internal *si;
2020	int rc = FAILED;
2021	unsigned long flags;
2022	int rval;
2023
2024	rval = fc_block_scsi_eh(sc_cmd);
2025	if (rval)
2026		return rval;
2027
2028	lport = shost_priv(sc_cmd->device->host);
2029	if (lport->state != LPORT_ST_READY)
2030		return rc;
2031	else if (!lport->link_up)
2032		return rc;
2033
2034	si = fc_get_scsi_internal(lport);
2035	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2036	fsp = CMD_SP(sc_cmd);
2037	if (!fsp) {
2038		/* command completed while scsi eh was setting up */
2039		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2040		return SUCCESS;
2041	}
2042	/* grab a ref so the fsp and sc_cmd cannot be relased from under us */
2043	fc_fcp_pkt_hold(fsp);
2044	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2045
2046	if (fc_fcp_lock_pkt(fsp)) {
2047		/* completed while we were waiting for timer to be deleted */
2048		rc = SUCCESS;
2049		goto release_pkt;
2050	}
2051
2052	rc = fc_fcp_pkt_abort(fsp);
2053	fc_fcp_unlock_pkt(fsp);
2054
2055release_pkt:
2056	fc_fcp_pkt_release(fsp);
2057	return rc;
2058}
2059EXPORT_SYMBOL(fc_eh_abort);
2060
2061/**
2062 * fc_eh_device_reset() - Reset a single LUN
2063 * @sc_cmd: The SCSI command which identifies the device whose
2064 *	    LUN is to be reset
2065 *
2066 * Set from SCSI host template.
2067 */
2068int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2069{
2070	struct fc_lport *lport;
2071	struct fc_fcp_pkt *fsp;
2072	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2073	int rc = FAILED;
2074	int rval;
2075
2076	rval = fc_block_scsi_eh(sc_cmd);
2077	if (rval)
2078		return rval;
2079
2080	lport = shost_priv(sc_cmd->device->host);
2081
2082	if (lport->state != LPORT_ST_READY)
2083		return rc;
2084
2085	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2086
2087	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2088	if (fsp == NULL) {
2089		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2090		goto out;
2091	}
2092
2093	/*
2094	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2095	 * the sc passed in is not setup for execution like when sent
2096	 * through the queuecommand callout.
2097	 */
2098	fsp->rport = rport;	/* set the remote port ptr */
2099
2100	/*
2101	 * flush outstanding commands
2102	 */
2103	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2104	fsp->state = FC_SRB_FREE;
2105	fc_fcp_pkt_release(fsp);
2106
2107out:
2108	return rc;
2109}
2110EXPORT_SYMBOL(fc_eh_device_reset);
2111
2112/**
2113 * fc_eh_host_reset() - Reset a Scsi_Host.
2114 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2115 */
2116int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2117{
2118	struct Scsi_Host *shost = sc_cmd->device->host;
2119	struct fc_lport *lport = shost_priv(shost);
2120	unsigned long wait_tmo;
2121
2122	FC_SCSI_DBG(lport, "Resetting host\n");
2123
2124	fc_block_scsi_eh(sc_cmd);
2125
2126	lport->tt.lport_reset(lport);
2127	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2128	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2129							       wait_tmo))
2130		msleep(1000);
2131
2132	if (fc_fcp_lport_queue_ready(lport)) {
2133		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2134			     "on port (%6.6x)\n", lport->port_id);
2135		return SUCCESS;
2136	} else {
2137		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2138			     "port (%6.6x) is not ready.\n",
2139			     lport->port_id);
2140		return FAILED;
2141	}
2142}
2143EXPORT_SYMBOL(fc_eh_host_reset);
2144
2145/**
2146 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2147 * @sdev: The SCSI device that identifies the SCSI host
2148 *
2149 * Configures queue depth based on host's cmd_per_len. If not set
2150 * then we use the libfc default.
2151 */
2152int fc_slave_alloc(struct scsi_device *sdev)
2153{
2154	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2155
2156	if (!rport || fc_remote_port_chkready(rport))
2157		return -ENXIO;
2158
2159	if (sdev->tagged_supported)
2160		scsi_activate_tcq(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2161	else
2162		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev),
2163					FC_FCP_DFLT_QUEUE_DEPTH);
2164
2165	return 0;
2166}
2167EXPORT_SYMBOL(fc_slave_alloc);
2168
2169/**
2170 * fc_change_queue_depth() - Change a device's queue depth
2171 * @sdev:   The SCSI device whose queue depth is to change
2172 * @qdepth: The new queue depth
2173 * @reason: The resason for the change
2174 */
2175int fc_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
2176{
2177	switch (reason) {
2178	case SCSI_QDEPTH_DEFAULT:
2179		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2180		break;
2181	case SCSI_QDEPTH_QFULL:
2182		scsi_track_queue_full(sdev, qdepth);
2183		break;
2184	case SCSI_QDEPTH_RAMP_UP:
2185		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2186		break;
2187	default:
2188		return -EOPNOTSUPP;
2189	}
2190	return sdev->queue_depth;
2191}
2192EXPORT_SYMBOL(fc_change_queue_depth);
2193
2194/**
2195 * fc_change_queue_type() - Change a device's queue type
2196 * @sdev:     The SCSI device whose queue depth is to change
2197 * @tag_type: Identifier for queue type
2198 */
2199int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2200{
2201	if (sdev->tagged_supported) {
2202		scsi_set_tag_type(sdev, tag_type);
2203		if (tag_type)
2204			scsi_activate_tcq(sdev, sdev->queue_depth);
2205		else
2206			scsi_deactivate_tcq(sdev, sdev->queue_depth);
2207	} else
2208		tag_type = 0;
2209
2210	return tag_type;
2211}
2212EXPORT_SYMBOL(fc_change_queue_type);
2213
2214/**
2215 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2216 * @lport: The local port that no longer needs the FCP layer
2217 */
2218void fc_fcp_destroy(struct fc_lport *lport)
2219{
2220	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2221
2222	if (!list_empty(&si->scsi_pkt_queue))
2223		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2224		       "port (%6.6x)\n", lport->port_id);
2225
2226	mempool_destroy(si->scsi_pkt_pool);
2227	kfree(si);
2228	lport->scsi_priv = NULL;
2229}
2230EXPORT_SYMBOL(fc_fcp_destroy);
2231
2232int fc_setup_fcp(void)
2233{
2234	int rc = 0;
2235
2236	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2237					    sizeof(struct fc_fcp_pkt),
2238					    0, SLAB_HWCACHE_ALIGN, NULL);
2239	if (!scsi_pkt_cachep) {
2240		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2241		       "module load failed!");
2242		rc = -ENOMEM;
2243	}
2244
2245	return rc;
2246}
2247
2248void fc_destroy_fcp(void)
2249{
2250	if (scsi_pkt_cachep)
2251		kmem_cache_destroy(scsi_pkt_cachep);
2252}
2253
2254/**
2255 * fc_fcp_init() - Initialize the FCP layer for a local port
2256 * @lport: The local port to initialize the exchange layer for
2257 */
2258int fc_fcp_init(struct fc_lport *lport)
2259{
2260	int rc;
2261	struct fc_fcp_internal *si;
2262
2263	if (!lport->tt.fcp_cmd_send)
2264		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2265
2266	if (!lport->tt.fcp_cleanup)
2267		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2268
2269	if (!lport->tt.fcp_abort_io)
2270		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2271
2272	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2273	if (!si)
2274		return -ENOMEM;
2275	lport->scsi_priv = si;
2276	si->max_can_queue = lport->host->can_queue;
2277	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2278	spin_lock_init(&si->scsi_queue_lock);
2279
2280	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2281	if (!si->scsi_pkt_pool) {
2282		rc = -ENOMEM;
2283		goto free_internal;
2284	}
2285	return 0;
2286
2287free_internal:
2288	kfree(si);
2289	return rc;
2290}
2291EXPORT_SYMBOL(fc_fcp_init);