git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/qla2xxx/qla_iocb.c

   1 /******************************************************************************
   2  *                  QLOGIC LINUX SOFTWARE
   3  *
   4  * QLogic ISP2x00 device driver for Linux 2.6.x
   5  * Copyright (C) 2003-2005 QLogic Corporation
   6  * (www.qlogic.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  ******************************************************************************/
  19
  20 #include "qla_def.h"
  21
  22 #include <linux/blkdev.h>
  23 #include <linux/delay.h>
  24
  25 #include <scsi/scsi_tcq.h>
  26
  27 static inline uint16_t qla2x00_get_cmd_direction(struct scsi_cmnd *cmd);
  28 static inline cont_entry_t *qla2x00_prep_cont_type0_iocb(scsi_qla_host_t *);
  29 static inline cont_a64_entry_t *qla2x00_prep_cont_type1_iocb(scsi_qla_host_t *);
  30 static request_t *qla2x00_req_pkt(scsi_qla_host_t *ha);
  31
  32 /**
  33  * qla2x00_get_cmd_direction() - Determine control_flag data direction.
  34  * @cmd: SCSI command
  35  *
  36  * Returns the proper CF_* direction based on CDB.
  37  */
  38 static inline uint16_t
  39 qla2x00_get_cmd_direction(struct scsi_cmnd *cmd)
  40 {
  41         uint16_t cflags;
  42
  43         cflags = 0;
  44
  45         /* Set transfer direction */
  46         if (cmd->sc_data_direction == DMA_TO_DEVICE)
  47                 cflags = CF_WRITE;
  48         else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
  49                 cflags = CF_READ;
  50         return (cflags);
  51 }
  52
  53 /**
  54  * qla2x00_calc_iocbs_32() - Determine number of Command Type 2 and
  55  * Continuation Type 0 IOCBs to allocate.
  56  *
  57  * @dsds: number of data segment decriptors needed
  58  *
  59  * Returns the number of IOCB entries needed to store @dsds.
  60  */
  61 uint16_t
  62 qla2x00_calc_iocbs_32(uint16_t dsds)
  63 {
  64         uint16_t iocbs;
  65
  66         iocbs = 1;
  67         if (dsds > 3) {
  68                 iocbs += (dsds - 3) / 7;
  69                 if ((dsds - 3) % 7)
  70                         iocbs++;
  71         }
  72         return (iocbs);
  73 }
  74
  75 /**
  76  * qla2x00_calc_iocbs_64() - Determine number of Command Type 3 and
  77  * Continuation Type 1 IOCBs to allocate.
  78  *
  79  * @dsds: number of data segment decriptors needed
  80  *
  81  * Returns the number of IOCB entries needed to store @dsds.
  82  */
  83 uint16_t
  84 qla2x00_calc_iocbs_64(uint16_t dsds)
  85 {
  86         uint16_t iocbs;
  87
  88         iocbs = 1;
  89         if (dsds > 2) {
  90                 iocbs += (dsds - 2) / 5;
  91                 if ((dsds - 2) % 5)
  92                         iocbs++;
  93         }
  94         return (iocbs);
  95 }
  96
  97 /**
  98  * qla2x00_prep_cont_type0_iocb() - Initialize a Continuation Type 0 IOCB.
  99  * @ha: HA context
 100  *
 101  * Returns a pointer to the Continuation Type 0 IOCB packet.
 102  */
 103 static inline cont_entry_t *
 104 qla2x00_prep_cont_type0_iocb(scsi_qla_host_t *ha)
 105 {
 106         cont_entry_t *cont_pkt;
 107
 108         /* Adjust ring index. */
 109         ha->req_ring_index++;
 110         if (ha->req_ring_index == ha->request_q_length) {
 111                 ha->req_ring_index = 0;
 112                 ha->request_ring_ptr = ha->request_ring;
 113         } else {
 114                 ha->request_ring_ptr++;
 115         }
 116
 117         cont_pkt = (cont_entry_t *)ha->request_ring_ptr;
 118
 119         /* Load packet defaults. */
 120         *((uint32_t *)(&cont_pkt->entry_type)) =
 121             __constant_cpu_to_le32(CONTINUE_TYPE);
 122
 123         return (cont_pkt);
 124 }
 125
 126 /**
 127  * qla2x00_prep_cont_type1_iocb() - Initialize a Continuation Type 1 IOCB.
 128  * @ha: HA context
 129  *
 130  * Returns a pointer to the continuation type 1 IOCB packet.
 131  */
 132 static inline cont_a64_entry_t *
 133 qla2x00_prep_cont_type1_iocb(scsi_qla_host_t *ha)
 134 {
 135         cont_a64_entry_t *cont_pkt;
 136
 137         /* Adjust ring index. */
 138         ha->req_ring_index++;
 139         if (ha->req_ring_index == ha->request_q_length) {
 140                 ha->req_ring_index = 0;
 141                 ha->request_ring_ptr = ha->request_ring;
 142         } else {
 143                 ha->request_ring_ptr++;
 144         }
 145
 146         cont_pkt = (cont_a64_entry_t *)ha->request_ring_ptr;
 147
 148         /* Load packet defaults. */
 149         *((uint32_t *)(&cont_pkt->entry_type)) =
 150             __constant_cpu_to_le32(CONTINUE_A64_TYPE);
 151
 152         return (cont_pkt);
 153 }
 154
 155 /**
 156  * qla2x00_build_scsi_iocbs_32() - Build IOCB command utilizing 32bit
 157  * capable IOCB types.
 158  *
 159  * @sp: SRB command to process
 160  * @cmd_pkt: Command type 2 IOCB
 161  * @tot_dsds: Total number of segments to transfer
 162  */
 163 void qla2x00_build_scsi_iocbs_32(srb_t *sp, cmd_entry_t *cmd_pkt,
 164     uint16_t tot_dsds)
 165 {
 166         uint16_t        avail_dsds;
 167         uint32_t        *cur_dsd;
 168         scsi_qla_host_t *ha;
 169         struct scsi_cmnd *cmd;
 170
 171         cmd = sp->cmd;
 172
 173         /* Update entry type to indicate Command Type 2 IOCB */
 174         *((uint32_t *)(&cmd_pkt->entry_type)) =
 175             __constant_cpu_to_le32(COMMAND_TYPE);
 176
 177         /* No data transfer */
 178         if (cmd->request_bufflen == 0 || cmd->sc_data_direction == DMA_NONE) {
 179                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
 180                 return;
 181         }
 182
 183         ha = sp->ha;
 184
 185         cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));
 186
 187         /* Three DSDs are available in the Command Type 2 IOCB */
 188         avail_dsds = 3;
 189         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
 190
 191         /* Load data segments */
 192         if (cmd->use_sg != 0) {
 193                 struct  scatterlist *cur_seg;
 194                 struct  scatterlist *end_seg;
 195
 196                 cur_seg = (struct scatterlist *)cmd->request_buffer;
 197                 end_seg = cur_seg + tot_dsds;
 198                 while (cur_seg < end_seg) {
 199                         cont_entry_t    *cont_pkt;
 200
 201                         /* Allocate additional continuation packets? */
 202                         if (avail_dsds == 0) {
 203                                 /*
 204                                  * Seven DSDs are available in the Continuation
 205                                  * Type 0 IOCB.
 206                                  */
 207                                 cont_pkt = qla2x00_prep_cont_type0_iocb(ha);
 208                                 cur_dsd = (uint32_t *)&cont_pkt->dseg_0_address;
 209                                 avail_dsds = 7;
 210                         }
 211
 212                         *cur_dsd++ = cpu_to_le32(sg_dma_address(cur_seg));
 213                         *cur_dsd++ = cpu_to_le32(sg_dma_len(cur_seg));
 214                         avail_dsds--;
 215
 216                         cur_seg++;
 217                 }
 218         } else {
 219                 *cur_dsd++ = cpu_to_le32(sp->dma_handle);
 220                 *cur_dsd++ = cpu_to_le32(cmd->request_bufflen);
 221         }
 222 }
 223
 224 /**
 225  * qla2x00_build_scsi_iocbs_64() - Build IOCB command utilizing 64bit
 226  * capable IOCB types.
 227  *
 228  * @sp: SRB command to process
 229  * @cmd_pkt: Command type 3 IOCB
 230  * @tot_dsds: Total number of segments to transfer
 231  */
 232 void qla2x00_build_scsi_iocbs_64(srb_t *sp, cmd_entry_t *cmd_pkt,
 233     uint16_t tot_dsds)
 234 {
 235         uint16_t        avail_dsds;
 236         uint32_t        *cur_dsd;
 237         scsi_qla_host_t *ha;
 238         struct scsi_cmnd *cmd;
 239
 240         cmd = sp->cmd;
 241
 242         /* Update entry type to indicate Command Type 3 IOCB */
 243         *((uint32_t *)(&cmd_pkt->entry_type)) =
 244             __constant_cpu_to_le32(COMMAND_A64_TYPE);
 245
 246         /* No data transfer */
 247         if (cmd->request_bufflen == 0 || cmd->sc_data_direction == DMA_NONE) {
 248                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
 249                 return;
 250         }
 251
 252         ha = sp->ha;
 253
 254         cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(cmd));
 255
 256         /* Two DSDs are available in the Command Type 3 IOCB */
 257         avail_dsds = 2;
 258         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
 259
 260         /* Load data segments */
 261         if (cmd->use_sg != 0) {
 262                 struct  scatterlist *cur_seg;
 263                 struct  scatterlist *end_seg;
 264
 265                 cur_seg = (struct scatterlist *)cmd->request_buffer;
 266                 end_seg = cur_seg + tot_dsds;
 267                 while (cur_seg < end_seg) {
 268                         dma_addr_t      sle_dma;
 269                         cont_a64_entry_t *cont_pkt;
 270
 271                         /* Allocate additional continuation packets? */
 272                         if (avail_dsds == 0) {
 273                                 /*
 274                                  * Five DSDs are available in the Continuation
 275                                  * Type 1 IOCB.
 276                                  */
 277                                 cont_pkt = qla2x00_prep_cont_type1_iocb(ha);
 278                                 cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
 279                                 avail_dsds = 5;
 280                         }
 281
 282                         sle_dma = sg_dma_address(cur_seg);
 283                         *cur_dsd++ = cpu_to_le32(LSD(sle_dma));
 284                         *cur_dsd++ = cpu_to_le32(MSD(sle_dma));
 285                         *cur_dsd++ = cpu_to_le32(sg_dma_len(cur_seg));
 286                         avail_dsds--;
 287
 288                         cur_seg++;
 289                 }
 290         } else {
 291                 *cur_dsd++ = cpu_to_le32(LSD(sp->dma_handle));
 292                 *cur_dsd++ = cpu_to_le32(MSD(sp->dma_handle));
 293                 *cur_dsd++ = cpu_to_le32(cmd->request_bufflen);
 294         }
 295 }
 296
 297 /**
 298  * qla2x00_start_scsi() - Send a SCSI command to the ISP
 299  * @sp: command to send to the ISP
 300  *
 301  * Returns non-zero if a failure occured, else zero.
 302  */
 303 int
 304 qla2x00_start_scsi(srb_t *sp)
 305 {
 306         int             ret;
 307         unsigned long   flags;
 308         scsi_qla_host_t *ha;
 309         struct scsi_cmnd *cmd;
 310         uint32_t        *clr_ptr;
 311         uint32_t        index;
 312         uint32_t        handle;
 313         cmd_entry_t     *cmd_pkt;
 314         struct scatterlist *sg;
 315         uint16_t        cnt;
 316         uint16_t        req_cnt;
 317         uint16_t        tot_dsds;
 318         struct device_reg_2xxx __iomem *reg;
 319         char            tag[2];
 320
 321         /* Setup device pointers. */
 322         ret = 0;
 323         ha = sp->ha;
 324         reg = &ha->iobase->isp;
 325         cmd = sp->cmd;
 326         /* So we know we haven't pci_map'ed anything yet */
 327         tot_dsds = 0;
 328
 329         /* Send marker if required */
 330         if (ha->marker_needed != 0) {
 331                 if (qla2x00_marker(ha, 0, 0, MK_SYNC_ALL) != QLA_SUCCESS) {
 332                         return (QLA_FUNCTION_FAILED);
 333                 }
 334                 ha->marker_needed = 0;
 335         }
 336
 337         /* Acquire ring specific lock */
 338         spin_lock_irqsave(&ha->hardware_lock, flags);
 339
 340         /* Check for room in outstanding command list. */
 341         handle = ha->current_outstanding_cmd;
 342         for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
 343                 handle++;
 344                 if (handle == MAX_OUTSTANDING_COMMANDS)
 345                         handle = 1;
 346                 if (ha->outstanding_cmds[handle] == 0)
 347                         break;
 348         }
 349         if (index == MAX_OUTSTANDING_COMMANDS)
 350                 goto queuing_error;
 351
 352         /* Map the sg table so we have an accurate count of sg entries needed */
 353         if (cmd->use_sg) {
 354                 sg = (struct scatterlist *) cmd->request_buffer;
 355                 tot_dsds = pci_map_sg(ha->pdev, sg, cmd->use_sg,
 356                     cmd->sc_data_direction);
 357                 if (tot_dsds == 0)
 358                         goto queuing_error;
 359         } else if (cmd->request_bufflen) {
 360                 dma_addr_t      req_dma;
 361
 362                 req_dma = pci_map_single(ha->pdev, cmd->request_buffer,
 363                     cmd->request_bufflen, cmd->sc_data_direction);
 364                 if (dma_mapping_error(req_dma))
 365                         goto queuing_error;
 366
 367                 sp->dma_handle = req_dma;
 368                 tot_dsds = 1;
 369         }
 370
 371         /* Calculate the number of request entries needed. */
 372         req_cnt = ha->isp_ops.calc_req_entries(tot_dsds);
 373         if (ha->req_q_cnt < (req_cnt + 2)) {
 374                 cnt = RD_REG_WORD_RELAXED(ISP_REQ_Q_OUT(ha, reg));
 375                 if (ha->req_ring_index < cnt)
 376                         ha->req_q_cnt = cnt - ha->req_ring_index;
 377                 else
 378                         ha->req_q_cnt = ha->request_q_length -
 379                             (ha->req_ring_index - cnt);
 380         }
 381         if (ha->req_q_cnt < (req_cnt + 2))
 382                 goto queuing_error;
 383
 384         /* Build command packet */
 385         ha->current_outstanding_cmd = handle;
 386         ha->outstanding_cmds[handle] = sp;
 387         sp->ha = ha;
 388         sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
 389         ha->req_q_cnt -= req_cnt;
 390
 391         cmd_pkt = (cmd_entry_t *)ha->request_ring_ptr;
 392         cmd_pkt->handle = handle;
 393         /* Zero out remaining portion of packet. */
 394         clr_ptr = (uint32_t *)cmd_pkt + 2;
 395         memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
 396         cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);
 397
 398         /* Set target ID and LUN number*/
 399         SET_TARGET_ID(ha, cmd_pkt->target, sp->fcport->loop_id);
 400         cmd_pkt->lun = cpu_to_le16(sp->cmd->device->lun);
 401
 402         /* Update tagged queuing modifier */
 403         cmd_pkt->control_flags = __constant_cpu_to_le16(CF_SIMPLE_TAG);
 404         if (scsi_populate_tag_msg(cmd, tag)) {
 405                 switch (tag[0]) {
 406                 case MSG_HEAD_TAG:
 407                         cmd_pkt->control_flags =
 408                             __constant_cpu_to_le16(CF_HEAD_TAG);
 409                         break;
 410                 case MSG_ORDERED_TAG:
 411                         cmd_pkt->control_flags =
 412                             __constant_cpu_to_le16(CF_ORDERED_TAG);
 413                         break;
 414                 }
 415         }
 416
 417         /* Load SCSI command packet. */
 418         memcpy(cmd_pkt->scsi_cdb, cmd->cmnd, cmd->cmd_len);
 419         cmd_pkt->byte_count = cpu_to_le32((uint32_t)cmd->request_bufflen);
 420
 421         /* Build IOCB segments */
 422         ha->isp_ops.build_iocbs(sp, cmd_pkt, tot_dsds);
 423
 424         /* Set total data segment count. */
 425         cmd_pkt->entry_count = (uint8_t)req_cnt;
 426         wmb();
 427
 428         /* Adjust ring index. */
 429         ha->req_ring_index++;
 430         if (ha->req_ring_index == ha->request_q_length) {
 431                 ha->req_ring_index = 0;
 432                 ha->request_ring_ptr = ha->request_ring;
 433         } else
 434                 ha->request_ring_ptr++;
 435
 436         sp->flags |= SRB_DMA_VALID;
 437         sp->state = SRB_ACTIVE_STATE;
 438
 439         /* Set chip new ring index. */
 440         WRT_REG_WORD(ISP_REQ_Q_IN(ha, reg), ha->req_ring_index);
 441         RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, reg));     /* PCI Posting. */
 442
 443         spin_unlock_irqrestore(&ha->hardware_lock, flags);
 444         return (QLA_SUCCESS);
 445
 446 queuing_error:
 447         if (cmd->use_sg && tot_dsds) {
 448                 sg = (struct scatterlist *) cmd->request_buffer;
 449                 pci_unmap_sg(ha->pdev, sg, cmd->use_sg,
 450                     cmd->sc_data_direction);
 451         } else if (tot_dsds) {
 452                 pci_unmap_single(ha->pdev, sp->dma_handle,
 453                     cmd->request_bufflen, cmd->sc_data_direction);
 454         }
 455         spin_unlock_irqrestore(&ha->hardware_lock, flags);
 456
 457         return (QLA_FUNCTION_FAILED);
 458 }
 459
 460 /**
 461  * qla2x00_marker() - Send a marker IOCB to the firmware.
 462  * @ha: HA context
 463  * @loop_id: loop ID
 464  * @lun: LUN
 465  * @type: marker modifier
 466  *
 467  * Can be called from both normal and interrupt context.
 468  *
 469  * Returns non-zero if a failure occured, else zero.
 470  */
 471 int
 472 __qla2x00_marker(scsi_qla_host_t *ha, uint16_t loop_id, uint16_t lun,
 473     uint8_t type)
 474 {
 475         mrk_entry_t *mrk;
 476         struct mrk_entry_24xx *mrk24;
 477
 478         mrk24 = NULL;
 479         mrk = (mrk_entry_t *)qla2x00_req_pkt(ha);
 480         if (mrk == NULL) {
 481                 DEBUG2_3(printk("%s(%ld): failed to allocate Marker IOCB.\n",
 482                     __func__, ha->host_no));
 483
 484                 return (QLA_FUNCTION_FAILED);
 485         }
 486
 487         mrk->entry_type = MARKER_TYPE;
 488         mrk->modifier = type;
 489         if (type != MK_SYNC_ALL) {
 490                 if (IS_QLA24XX(ha) || IS_QLA25XX(ha)) {
 491                         mrk24 = (struct mrk_entry_24xx *) mrk;
 492                         mrk24->nport_handle = cpu_to_le16(loop_id);
 493                         mrk24->lun[1] = LSB(lun);
 494                         mrk24->lun[2] = MSB(lun);
 495                 } else {
 496                         SET_TARGET_ID(ha, mrk->target, loop_id);
 497                         mrk->lun = cpu_to_le16(lun);
 498                 }
 499         }
 500         wmb();
 501
 502         qla2x00_isp_cmd(ha);
 503
 504         return (QLA_SUCCESS);
 505 }
 506
 507 int
 508 qla2x00_marker(scsi_qla_host_t *ha, uint16_t loop_id, uint16_t lun,
 509     uint8_t type)
 510 {
 511         int ret;
 512         unsigned long flags = 0;
 513
 514         spin_lock_irqsave(&ha->hardware_lock, flags);
 515         ret = __qla2x00_marker(ha, loop_id, lun, type);
 516         spin_unlock_irqrestore(&ha->hardware_lock, flags);
 517
 518         return (ret);
 519 }
 520
 521 /**
 522  * qla2x00_req_pkt() - Retrieve a request packet from the request ring.
 523  * @ha: HA context
 524  *
 525  * Note: The caller must hold the hardware lock before calling this routine.
 526  *
 527  * Returns NULL if function failed, else, a pointer to the request packet.
 528  */
 529 static request_t *
 530 qla2x00_req_pkt(scsi_qla_host_t *ha)
 531 {
 532         device_reg_t __iomem *reg = ha->iobase;
 533         request_t       *pkt = NULL;
 534         uint16_t        cnt;
 535         uint32_t        *dword_ptr;
 536         uint32_t        timer;
 537         uint16_t        req_cnt = 1;
 538
 539         /* Wait 1 second for slot. */
 540         for (timer = HZ; timer; timer--) {
 541                 if ((req_cnt + 2) >= ha->req_q_cnt) {
 542                         /* Calculate number of free request entries. */
 543                         if (IS_QLA24XX(ha) || IS_QLA25XX(ha))
 544                                 cnt = (uint16_t)RD_REG_DWORD(
 545                                     &reg->isp24.req_q_out);
 546                         else
 547                                 cnt = qla2x00_debounce_register(
 548                                     ISP_REQ_Q_OUT(ha, &reg->isp));
 549                         if  (ha->req_ring_index < cnt)
 550                                 ha->req_q_cnt = cnt - ha->req_ring_index;
 551                         else
 552                                 ha->req_q_cnt = ha->request_q_length -
 553                                     (ha->req_ring_index - cnt);
 554                 }
 555                 /* If room for request in request ring. */
 556                 if ((req_cnt + 2) < ha->req_q_cnt) {
 557                         ha->req_q_cnt--;
 558                         pkt = ha->request_ring_ptr;
 559
 560                         /* Zero out packet. */
 561                         dword_ptr = (uint32_t *)pkt;
 562                         for (cnt = 0; cnt < REQUEST_ENTRY_SIZE / 4; cnt++)
 563                                 *dword_ptr++ = 0;
 564
 565                         /* Set system defined field. */
 566                         pkt->sys_define = (uint8_t)ha->req_ring_index;
 567
 568                         /* Set entry count. */
 569                         pkt->entry_count = 1;
 570
 571                         break;
 572                 }
 573
 574                 /* Release ring specific lock */
 575                 spin_unlock(&ha->hardware_lock);
 576
 577                 udelay(2);   /* 2 us */
 578
 579                 /* Check for pending interrupts. */
 580                 /* During init we issue marker directly */
 581                 if (!ha->marker_needed)
 582                         qla2x00_poll(ha);
 583
 584                 spin_lock_irq(&ha->hardware_lock);
 585         }
 586         if (!pkt) {
 587                 DEBUG2_3(printk("%s(): **** FAILED ****\n", __func__));
 588         }
 589
 590         return (pkt);
 591 }
 592
 593 /**
 594  * qla2x00_isp_cmd() - Modify the request ring pointer.
 595  * @ha: HA context
 596  *
 597  * Note: The caller must hold the hardware lock before calling this routine.
 598  */
 599 void
 600 qla2x00_isp_cmd(scsi_qla_host_t *ha)
 601 {
 602         device_reg_t __iomem *reg = ha->iobase;
 603
 604         DEBUG5(printk("%s(): IOCB data:\n", __func__));
 605         DEBUG5(qla2x00_dump_buffer(
 606             (uint8_t *)ha->request_ring_ptr, REQUEST_ENTRY_SIZE));
 607
 608         /* Adjust ring index. */
 609         ha->req_ring_index++;
 610         if (ha->req_ring_index == ha->request_q_length) {
 611                 ha->req_ring_index = 0;
 612                 ha->request_ring_ptr = ha->request_ring;
 613         } else
 614                 ha->request_ring_ptr++;
 615
 616         /* Set chip new ring index. */
 617         if (IS_QLA24XX(ha) || IS_QLA25XX(ha)) {
 618                 WRT_REG_DWORD(&reg->isp24.req_q_in, ha->req_ring_index);
 619                 RD_REG_DWORD_RELAXED(&reg->isp24.req_q_in);
 620         } else {
 621                 WRT_REG_WORD(ISP_REQ_Q_IN(ha, &reg->isp), ha->req_ring_index);
 622                 RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, &reg->isp));
 623         }
 624
 625 }
 626
 627 /**
 628  * qla24xx_calc_iocbs() - Determine number of Command Type 3 and
 629  * Continuation Type 1 IOCBs to allocate.
 630  *
 631  * @dsds: number of data segment decriptors needed
 632  *
 633  * Returns the number of IOCB entries needed to store @dsds.
 634  */
 635 static inline uint16_t
 636 qla24xx_calc_iocbs(uint16_t dsds)
 637 {
 638         uint16_t iocbs;
 639
 640         iocbs = 1;
 641         if (dsds > 1) {
 642                 iocbs += (dsds - 1) / 5;
 643                 if ((dsds - 1) % 5)
 644                         iocbs++;
 645         }
 646         return iocbs;
 647 }
 648
 649 /**
 650  * qla24xx_build_scsi_iocbs() - Build IOCB command utilizing Command Type 7
 651  * IOCB types.
 652  *
 653  * @sp: SRB command to process
 654  * @cmd_pkt: Command type 3 IOCB
 655  * @tot_dsds: Total number of segments to transfer
 656  */
 657 static inline void
 658 qla24xx_build_scsi_iocbs(srb_t *sp, struct cmd_type_7 *cmd_pkt,
 659     uint16_t tot_dsds)
 660 {
 661         uint16_t        avail_dsds;
 662         uint32_t        *cur_dsd;
 663         scsi_qla_host_t *ha;
 664         struct scsi_cmnd *cmd;
 665
 666         cmd = sp->cmd;
 667
 668         /* Update entry type to indicate Command Type 3 IOCB */
 669         *((uint32_t *)(&cmd_pkt->entry_type)) =
 670             __constant_cpu_to_le32(COMMAND_TYPE_7);
 671
 672         /* No data transfer */
 673         if (cmd->request_bufflen == 0 || cmd->sc_data_direction == DMA_NONE) {
 674                 cmd_pkt->byte_count = __constant_cpu_to_le32(0);
 675                 return;
 676         }
 677
 678         ha = sp->ha;
 679
 680         /* Set transfer direction */
 681         if (cmd->sc_data_direction == DMA_TO_DEVICE)
 682                 cmd_pkt->task_mgmt_flags =
 683                     __constant_cpu_to_le16(TMF_WRITE_DATA);
 684         else if (cmd->sc_data_direction == DMA_FROM_DEVICE)
 685                 cmd_pkt->task_mgmt_flags =
 686                     __constant_cpu_to_le16(TMF_READ_DATA);
 687
 688         /* One DSD is available in the Command Type 3 IOCB */
 689         avail_dsds = 1;
 690         cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;
 691
 692         /* Load data segments */
 693         if (cmd->use_sg != 0) {
 694                 struct  scatterlist *cur_seg;
 695                 struct  scatterlist *end_seg;
 696
 697                 cur_seg = (struct scatterlist *)cmd->request_buffer;
 698                 end_seg = cur_seg + tot_dsds;
 699                 while (cur_seg < end_seg) {
 700                         dma_addr_t      sle_dma;
 701                         cont_a64_entry_t *cont_pkt;
 702
 703                         /* Allocate additional continuation packets? */
 704                         if (avail_dsds == 0) {
 705                                 /*
 706                                  * Five DSDs are available in the Continuation
 707                                  * Type 1 IOCB.
 708                                  */
 709                                 cont_pkt = qla2x00_prep_cont_type1_iocb(ha);
 710                                 cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
 711                                 avail_dsds = 5;
 712                         }
 713
 714                         sle_dma = sg_dma_address(cur_seg);
 715                         *cur_dsd++ = cpu_to_le32(LSD(sle_dma));
 716                         *cur_dsd++ = cpu_to_le32(MSD(sle_dma));
 717                         *cur_dsd++ = cpu_to_le32(sg_dma_len(cur_seg));
 718                         avail_dsds--;
 719
 720                         cur_seg++;
 721                 }
 722         } else {
 723                 *cur_dsd++ = cpu_to_le32(LSD(sp->dma_handle));
 724                 *cur_dsd++ = cpu_to_le32(MSD(sp->dma_handle));
 725                 *cur_dsd++ = cpu_to_le32(cmd->request_bufflen);
 726         }
 727 }
 728
 729
 730 /**
 731  * qla24xx_start_scsi() - Send a SCSI command to the ISP
 732  * @sp: command to send to the ISP
 733  *
 734  * Returns non-zero if a failure occured, else zero.
 735  */
 736 int
 737 qla24xx_start_scsi(srb_t *sp)
 738 {
 739         int             ret;
 740         unsigned long   flags;
 741         scsi_qla_host_t *ha;
 742         struct scsi_cmnd *cmd;
 743         uint32_t        *clr_ptr;
 744         uint32_t        index;
 745         uint32_t        handle;
 746         struct cmd_type_7 *cmd_pkt;
 747         struct scatterlist *sg;
 748         uint16_t        cnt;
 749         uint16_t        req_cnt;
 750         uint16_t        tot_dsds;
 751         struct device_reg_24xx __iomem *reg;
 752         char            tag[2];
 753
 754         /* Setup device pointers. */
 755         ret = 0;
 756         ha = sp->ha;
 757         reg = &ha->iobase->isp24;
 758         cmd = sp->cmd;
 759         /* So we know we haven't pci_map'ed anything yet */
 760         tot_dsds = 0;
 761
 762         /* Send marker if required */
 763         if (ha->marker_needed != 0) {
 764                 if (qla2x00_marker(ha, 0, 0, MK_SYNC_ALL) != QLA_SUCCESS) {
 765                         return QLA_FUNCTION_FAILED;
 766                 }
 767                 ha->marker_needed = 0;
 768         }
 769
 770         /* Acquire ring specific lock */
 771         spin_lock_irqsave(&ha->hardware_lock, flags);
 772
 773         /* Check for room in outstanding command list. */
 774         handle = ha->current_outstanding_cmd;
 775         for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
 776                 handle++;
 777                 if (handle == MAX_OUTSTANDING_COMMANDS)
 778                         handle = 1;
 779                 if (ha->outstanding_cmds[handle] == 0)
 780                         break;
 781         }
 782         if (index == MAX_OUTSTANDING_COMMANDS)
 783                 goto queuing_error;
 784
 785         /* Map the sg table so we have an accurate count of sg entries needed */
 786         if (cmd->use_sg) {
 787                 sg = (struct scatterlist *) cmd->request_buffer;
 788                 tot_dsds = pci_map_sg(ha->pdev, sg, cmd->use_sg,
 789                     cmd->sc_data_direction);
 790                 if (tot_dsds == 0)
 791                         goto queuing_error;
 792         } else if (cmd->request_bufflen) {
 793                 dma_addr_t      req_dma;
 794
 795                 req_dma = pci_map_single(ha->pdev, cmd->request_buffer,
 796                     cmd->request_bufflen, cmd->sc_data_direction);
 797                 if (dma_mapping_error(req_dma))
 798                         goto queuing_error;
 799
 800                 sp->dma_handle = req_dma;
 801                 tot_dsds = 1;
 802         }
 803
 804         req_cnt = qla24xx_calc_iocbs(tot_dsds);
 805         if (ha->req_q_cnt < (req_cnt + 2)) {
 806                 cnt = (uint16_t)RD_REG_DWORD_RELAXED(&reg->req_q_out);
 807                 if (ha->req_ring_index < cnt)
 808                         ha->req_q_cnt = cnt - ha->req_ring_index;
 809                 else
 810                         ha->req_q_cnt = ha->request_q_length -
 811                                 (ha->req_ring_index - cnt);
 812         }
 813         if (ha->req_q_cnt < (req_cnt + 2))
 814                 goto queuing_error;
 815
 816         /* Build command packet. */
 817         ha->current_outstanding_cmd = handle;
 818         ha->outstanding_cmds[handle] = sp;
 819         sp->ha = ha;
 820         sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
 821         ha->req_q_cnt -= req_cnt;
 822
 823         cmd_pkt = (struct cmd_type_7 *)ha->request_ring_ptr;
 824         cmd_pkt->handle = handle;
 825
 826         /* Zero out remaining portion of packet. */
 827         clr_ptr = (uint32_t *)cmd_pkt + 2;
 828         memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
 829         cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);
 830
 831         /* Set NPORT-ID and LUN number*/
 832         cmd_pkt->nport_handle = cpu_to_le16(sp->fcport->loop_id);
 833         cmd_pkt->port_id[0] = sp->fcport->d_id.b.al_pa;
 834         cmd_pkt->port_id[1] = sp->fcport->d_id.b.area;
 835         cmd_pkt->port_id[2] = sp->fcport->d_id.b.domain;
 836
 837         cmd_pkt->lun[1] = LSB(sp->cmd->device->lun);
 838         cmd_pkt->lun[2] = MSB(sp->cmd->device->lun);
 839
 840         /* Update tagged queuing modifier -- default is TSK_SIMPLE (0). */
 841         if (scsi_populate_tag_msg(cmd, tag)) {
 842                 switch (tag[0]) {
 843                 case MSG_HEAD_TAG:
 844                         cmd_pkt->task = TSK_HEAD_OF_QUEUE;
 845                         break;
 846                 case MSG_ORDERED_TAG:
 847                         cmd_pkt->task = TSK_ORDERED;
 848                         break;
 849                 }
 850         }
 851
 852         /* Load SCSI command packet. */
 853         memcpy(cmd_pkt->fcp_cdb, cmd->cmnd, cmd->cmd_len);
 854         host_to_fcp_swap(cmd_pkt->fcp_cdb, sizeof(cmd_pkt->fcp_cdb));
 855
 856         cmd_pkt->byte_count = cpu_to_le32((uint32_t)cmd->request_bufflen);
 857
 858         /* Build IOCB segments */
 859         qla24xx_build_scsi_iocbs(sp, cmd_pkt, tot_dsds);
 860
 861         /* Set total data segment count. */
 862         cmd_pkt->entry_count = (uint8_t)req_cnt;
 863         wmb();
 864
 865         /* Adjust ring index. */
 866         ha->req_ring_index++;
 867         if (ha->req_ring_index == ha->request_q_length) {
 868                 ha->req_ring_index = 0;
 869                 ha->request_ring_ptr = ha->request_ring;
 870         } else
 871                 ha->request_ring_ptr++;
 872
 873         sp->flags |= SRB_DMA_VALID;
 874         sp->state = SRB_ACTIVE_STATE;
 875
 876         /* Set chip new ring index. */
 877         WRT_REG_DWORD(&reg->req_q_in, ha->req_ring_index);
 878         RD_REG_DWORD_RELAXED(&reg->req_q_in);           /* PCI Posting. */
 879
 880         spin_unlock_irqrestore(&ha->hardware_lock, flags);
 881         return QLA_SUCCESS;
 882
 883 queuing_error:
 884         if (cmd->use_sg && tot_dsds) {
 885                 sg = (struct scatterlist *) cmd->request_buffer;
 886                 pci_unmap_sg(ha->pdev, sg, cmd->use_sg,
 887                     cmd->sc_data_direction);
 888         } else if (tot_dsds) {
 889                 pci_unmap_single(ha->pdev, sp->dma_handle,
 890                     cmd->request_bufflen, cmd->sc_data_direction);
 891         }
 892         spin_unlock_irqrestore(&ha->hardware_lock, flags);
 893
 894         return QLA_FUNCTION_FAILED;
 895 }