drivers/scsi/isci/request.h

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  * redistributing this file, you may do so under either license.
   4  *
   5  * GPL LICENSE SUMMARY
   6  *
   7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  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  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * BSD LICENSE
  25  *
  26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  *
  33  *   * Redistributions of source code must retain the above copyright
  34  *     notice, this list of conditions and the following disclaimer.
  35  *   * Redistributions in binary form must reproduce the above copyright
  36  *     notice, this list of conditions and the following disclaimer in
  37  *     the documentation and/or other materials provided with the
  38  *     distribution.
  39  *   * Neither the name of Intel Corporation nor the names of its
  40  *     contributors may be used to endorse or promote products derived
  41  *     from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  54  */
  55
  56 #ifndef _ISCI_REQUEST_H_
  57 #define _ISCI_REQUEST_H_
  58
  59 #include "isci.h"
  60 #include "host.h"
  61 #include "scu_task_context.h"
  62
  63 /**
  64  * struct isci_request_status - This enum defines the possible states of an I/O
  65  *    request.
  66  *
  67  *
  68  */
  69 enum isci_request_status {
  70         unallocated = 0x00,
  71         allocated   = 0x01,
  72         started     = 0x02,
  73         completed   = 0x03,
  74         aborting    = 0x04,
  75         aborted     = 0x05,
  76         terminating = 0x06,
  77         dead        = 0x07
  78 };
  79
  80 enum task_type {
  81         io_task  = 0,
  82         tmf_task = 1
  83 };
  84
  85 enum sci_request_protocol {
  86         SCIC_NO_PROTOCOL,
  87         SCIC_SMP_PROTOCOL,
  88         SCIC_SSP_PROTOCOL,
  89         SCIC_STP_PROTOCOL
  90 }; /* XXX remove me, use sas_task.{dev|task_proto} instead */;
  91
  92 struct scic_sds_stp_request {
  93         union {
  94                 u32 ncq;
  95
  96                 u32 udma;
  97
  98                 struct scic_sds_stp_pio_request {
  99                         /*
 100                          * Total transfer for the entire PIO request recorded
 101                          * at request constuction time.
 102                          *
 103                          * @todo Should we just decrement this value for each
 104                          * byte of data transitted or received to elemenate
 105                          * the current_transfer_bytes field?
 106                          */
 107                         u32 total_transfer_bytes;
 108
 109                         /*
 110                          * Total number of bytes received/transmitted in data
 111                          * frames since the start of the IO request.  At the
 112                          * end of the IO request this should equal the
 113                          * total_transfer_bytes.
 114                          */
 115                         u32 current_transfer_bytes;
 116
 117                         /*
 118                          * The number of bytes requested in the in the PIO
 119                          * setup.
 120                          */
 121                         u32 pio_transfer_bytes;
 122
 123                         /*
 124                          * PIO Setup ending status value to tell us if we need
 125                          * to wait for another FIS or if the transfer is
 126                          * complete. On the receipt of a D2H FIS this will be
 127                          * the status field of that FIS.
 128                          */
 129                         u8 ending_status;
 130
 131                         /*
 132                          * On receipt of a D2H FIS this will be the ending
 133                          * error field if the ending_status has the
 134                          * SATA_STATUS_ERR bit set.
 135                          */
 136                         u8 ending_error;
 137
 138                         struct scic_sds_request_pio_sgl {
 139                                 struct scu_sgl_element_pair *sgl_pair;
 140                                 u8 sgl_set;
 141                                 u32 sgl_offset;
 142                         } request_current;
 143                 } pio;
 144
 145                 struct {
 146                         /*
 147                          * The number of bytes requested in the PIO setup
 148                          * before CDB data frame.
 149                          */
 150                         u32 device_preferred_cdb_length;
 151                 } packet;
 152         } type;
 153 };
 154
 155 struct scic_sds_request {
 156         /*
 157          * This field contains the information for the base request state
 158          * machine.
 159          */
 160         struct sci_base_state_machine sm;
 161
 162         /*
 163          * This field simply points to the controller to which this IO request
 164          * is associated.
 165          */
 166         struct scic_sds_controller *owning_controller;
 167
 168         /*
 169          * This field simply points to the remote device to which this IO
 170          * request is associated.
 171          */
 172         struct scic_sds_remote_device *target_device;
 173
 174         /*
 175          * This field is utilized to determine if the SCI user is managing
 176          * the IO tag for this request or if the core is managing it.
 177          */
 178         bool was_tag_assigned_by_user;
 179
 180         /*
 181          * This field indicates the IO tag for this request.  The IO tag is
 182          * comprised of the task_index and a sequence count. The sequence count
 183          * is utilized to help identify tasks from one life to another.
 184          */
 185         u16 io_tag;
 186
 187         /*
 188          * This field specifies the protocol being utilized for this
 189          * IO request.
 190          */
 191         enum sci_request_protocol protocol;
 192
 193         /*
 194          * This field indicates the completion status taken from the SCUs
 195          * completion code.  It indicates the completion result for the SCU
 196          * hardware.
 197          */
 198         u32 scu_status;
 199
 200         /*
 201          * This field indicates the completion status returned to the SCI user.
 202          * It indicates the users view of the io request completion.
 203          */
 204         u32 sci_status;
 205
 206         /*
 207          * This field contains the value to be utilized when posting
 208          * (e.g. Post_TC, * Post_TC_Abort) this request to the silicon.
 209          */
 210         u32 post_context;
 211
 212         struct scu_task_context *task_context_buffer;
 213         struct scu_task_context tc ____cacheline_aligned;
 214
 215         /* could be larger with sg chaining */
 216         #define SCU_SGL_SIZE ((SCI_MAX_SCATTER_GATHER_ELEMENTS + 1) / 2)
 217         struct scu_sgl_element_pair sg_table[SCU_SGL_SIZE] __attribute__ ((aligned(32)));
 218
 219         /*
 220          * This field indicates if this request is a task management request or
 221          * normal IO request.
 222          */
 223         bool is_task_management_request;
 224
 225         /*
 226          * This field is a pointer to the stored rx frame data.  It is used in
 227          * STP internal requests and SMP response frames.  If this field is
 228          * non-NULL the saved frame must be released on IO request completion.
 229          *
 230          * @todo In the future do we want to keep a list of RX frame buffers?
 231          */
 232         u32 saved_rx_frame_index;
 233
 234         /*
 235          * This field in the recorded device sequence for the io request.
 236          * This is recorded during the build operation and is compared in the
 237          * start operation.  If the sequence is different then there was a
 238          * change of devices from the build to start operations.
 239          */
 240         u8 device_sequence;
 241
 242         union {
 243                 struct {
 244                         union {
 245                                 struct ssp_cmd_iu cmd;
 246                                 struct ssp_task_iu tmf;
 247                         };
 248                         union {
 249                                 struct ssp_response_iu rsp;
 250                                 u8 rsp_buf[SSP_RESP_IU_MAX_SIZE];
 251                         };
 252                 } ssp;
 253
 254                 struct {
 255                         struct smp_req cmd;
 256                         struct smp_resp rsp;
 257                 } smp;
 258
 259                 struct {
 260                         struct scic_sds_stp_request req;
 261                         struct host_to_dev_fis cmd;
 262                         struct dev_to_host_fis rsp;
 263                 } stp;
 264         };
 265
 266 };
 267
 268 static inline struct scic_sds_request *to_sci_req(struct scic_sds_stp_request *stp_req)
 269 {
 270         struct scic_sds_request *sci_req;
 271
 272         sci_req = container_of(stp_req, typeof(*sci_req), stp.req);
 273         return sci_req;
 274 }
 275
 276 struct isci_request {
 277         enum isci_request_status status;
 278         enum task_type ttype;
 279         unsigned short io_tag;
 280         bool complete_in_target;
 281         bool terminated;
 282
 283         union ttype_ptr_union {
 284                 struct sas_task *io_task_ptr;   /* When ttype==io_task  */
 285                 struct isci_tmf *tmf_task_ptr;  /* When ttype==tmf_task */
 286         } ttype_ptr;
 287         struct isci_host *isci_host;
 288         struct isci_remote_device *isci_device;
 289         /* For use in the requests_to_{complete|abort} lists: */
 290         struct list_head completed_node;
 291         /* For use in the reqs_in_process list: */
 292         struct list_head dev_node;
 293         spinlock_t state_lock;
 294         dma_addr_t request_daddr;
 295         dma_addr_t zero_scatter_daddr;
 296
 297         unsigned int num_sg_entries;                    /* returned by pci_alloc_sg */
 298
 299         /** Note: "io_request_completion" is completed in two different ways
 300          * depending on whether this is a TMF or regular request.
 301          * - TMF requests are completed in the thread that started them;
 302          * - regular requests are completed in the request completion callback
 303          *   function.
 304          * This difference in operation allows the aborter of a TMF request
 305          * to be sure that once the TMF request completes, the I/O that the
 306          * TMF was aborting is guaranteed to have completed.
 307          */
 308         struct completion *io_request_completion;
 309         struct scic_sds_request sci;
 310 };
 311
 312 static inline struct isci_request *sci_req_to_ireq(struct scic_sds_request *sci_req)
 313 {
 314         struct isci_request *ireq = container_of(sci_req, typeof(*ireq), sci);
 315
 316         return ireq;
 317 }
 318
 319 /**
 320  * enum sci_base_request_states - This enumeration depicts all the states for
 321  *    the common request state machine.
 322  *
 323  *
 324  */
 325 enum sci_base_request_states {
 326         /*
 327          * Simply the initial state for the base request state machine.
 328          */
 329         SCI_REQ_INIT,
 330
 331         /*
 332          * This state indicates that the request has been constructed.
 333          * This state is entered from the INITIAL state.
 334          */
 335         SCI_REQ_CONSTRUCTED,
 336
 337         /*
 338          * This state indicates that the request has been started. This state
 339          * is entered from the CONSTRUCTED state.
 340          */
 341         SCI_REQ_STARTED,
 342
 343         SCI_REQ_STP_UDMA_WAIT_TC_COMP,
 344         SCI_REQ_STP_UDMA_WAIT_D2H,
 345
 346         SCI_REQ_STP_NON_DATA_WAIT_H2D,
 347         SCI_REQ_STP_NON_DATA_WAIT_D2H,
 348
 349         SCI_REQ_STP_SOFT_RESET_WAIT_H2D_ASSERTED,
 350         SCI_REQ_STP_SOFT_RESET_WAIT_H2D_DIAG,
 351         SCI_REQ_STP_SOFT_RESET_WAIT_D2H,
 352
 353         /*
 354          * While in this state the IO request object is waiting for the TC
 355          * completion notification for the H2D Register FIS
 356          */
 357         SCI_REQ_STP_PIO_WAIT_H2D,
 358
 359         /*
 360          * While in this state the IO request object is waiting for either a
 361          * PIO Setup FIS or a D2H register FIS.  The type of frame received is
 362          * based on the result of the prior frame and line conditions.
 363          */
 364         SCI_REQ_STP_PIO_WAIT_FRAME,
 365
 366         /*
 367          * While in this state the IO request object is waiting for a DATA
 368          * frame from the device.
 369          */
 370         SCI_REQ_STP_PIO_DATA_IN,
 371
 372         /*
 373          * While in this state the IO request object is waiting to transmit
 374          * the next data frame to the device.
 375          */
 376         SCI_REQ_STP_PIO_DATA_OUT,
 377
 378         /*
 379          * The AWAIT_TC_COMPLETION sub-state indicates that the started raw
 380          * task management request is waiting for the transmission of the
 381          * initial frame (i.e. command, task, etc.).
 382          */
 383         SCI_REQ_TASK_WAIT_TC_COMP,
 384
 385         /*
 386          * This sub-state indicates that the started task management request
 387          * is waiting for the reception of an unsolicited frame
 388          * (i.e. response IU).
 389          */
 390         SCI_REQ_TASK_WAIT_TC_RESP,
 391
 392         /*
 393          * This sub-state indicates that the started task management request
 394          * is waiting for the reception of an unsolicited frame
 395          * (i.e. response IU).
 396          */
 397         SCI_REQ_SMP_WAIT_RESP,
 398
 399         /*
 400          * The AWAIT_TC_COMPLETION sub-state indicates that the started SMP
 401          * request is waiting for the transmission of the initial frame
 402          * (i.e. command, task, etc.).
 403          */
 404         SCI_REQ_SMP_WAIT_TC_COMP,
 405
 406         /*
 407          * This state indicates that the request has completed.
 408          * This state is entered from the STARTED state. This state is entered
 409          * from the ABORTING state.
 410          */
 411         SCI_REQ_COMPLETED,
 412
 413         /*
 414          * This state indicates that the request is in the process of being
 415          * terminated/aborted.
 416          * This state is entered from the CONSTRUCTED state.
 417          * This state is entered from the STARTED state.
 418          */
 419         SCI_REQ_ABORTING,
 420
 421         /*
 422          * Simply the final state for the base request state machine.
 423          */
 424         SCI_REQ_FINAL,
 425 };
 426
 427 /**
 428  * scic_sds_request_get_controller() -
 429  *
 430  * This macro will return the controller for this io request object
 431  */
 432 #define scic_sds_request_get_controller(sci_req) \
 433         ((sci_req)->owning_controller)
 434
 435 /**
 436  * scic_sds_request_get_device() -
 437  *
 438  * This macro will return the device for this io request object
 439  */
 440 #define scic_sds_request_get_device(sci_req) \
 441         ((sci_req)->target_device)
 442
 443 /**
 444  * scic_sds_request_get_port() -
 445  *
 446  * This macro will return the port for this io request object
 447  */
 448 #define scic_sds_request_get_port(sci_req)      \
 449         scic_sds_remote_device_get_port(scic_sds_request_get_device(sci_req))
 450
 451 /**
 452  * scic_sds_request_get_post_context() -
 453  *
 454  * This macro returns the constructed post context result for the io request.
 455  */
 456 #define scic_sds_request_get_post_context(sci_req)      \
 457         ((sci_req)->post_context)
 458
 459 /**
 460  * scic_sds_request_get_task_context() -
 461  *
 462  * This is a helper macro to return the os handle for this request object.
 463  */
 464 #define scic_sds_request_get_task_context(request) \
 465         ((request)->task_context_buffer)
 466
 467 /**
 468  * scic_sds_request_set_status() -
 469  *
 470  * This macro will set the scu hardware status and sci request completion
 471  * status for an io request.
 472  */
 473 #define scic_sds_request_set_status(request, scu_status_code, sci_status_code) \
 474         { \
 475                 (request)->scu_status = (scu_status_code); \
 476                 (request)->sci_status = (sci_status_code); \
 477         }
 478
 479 /**
 480  * SCU_SGL_ZERO() -
 481  *
 482  * This macro zeros the hardware SGL element data
 483  */
 484 #define SCU_SGL_ZERO(scu_sge) \
 485         { \
 486                 (scu_sge).length = 0; \
 487                 (scu_sge).address_lower = 0; \
 488                 (scu_sge).address_upper = 0; \
 489                 (scu_sge).address_modifier = 0; \
 490         }
 491
 492 /**
 493  * SCU_SGL_COPY() -
 494  *
 495  * This macro copys the SGL Element data from the host os to the hardware SGL
 496  * elment data
 497  */
 498 #define SCU_SGL_COPY(scu_sge, os_sge) \
 499         { \
 500                 (scu_sge).length = sg_dma_len(sg); \
 501                 (scu_sge).address_upper = \
 502                         upper_32_bits(sg_dma_address(sg)); \
 503                 (scu_sge).address_lower = \
 504                         lower_32_bits(sg_dma_address(sg)); \
 505                 (scu_sge).address_modifier = 0; \
 506         }
 507
 508 enum sci_status scic_sds_request_start(struct scic_sds_request *sci_req);
 509 enum sci_status scic_sds_io_request_terminate(struct scic_sds_request *sci_req);
 510 enum sci_status
 511 scic_sds_io_request_event_handler(struct scic_sds_request *sci_req,
 512                                   u32 event_code);
 513 enum sci_status
 514 scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
 515                                   u32 frame_index);
 516 enum sci_status
 517 scic_sds_task_request_terminate(struct scic_sds_request *sci_req);
 518 extern enum sci_status
 519 scic_sds_request_complete(struct scic_sds_request *sci_req);
 520 extern enum sci_status
 521 scic_sds_io_request_tc_completion(struct scic_sds_request *sci_req, u32 code);
 522
 523 /* XXX open code in caller */
 524 static inline void *scic_request_get_virt_addr(struct scic_sds_request *sci_req,
 525                                                dma_addr_t phys_addr)
 526 {
 527         struct isci_request *ireq = sci_req_to_ireq(sci_req);
 528         dma_addr_t offset;
 529
 530         BUG_ON(phys_addr < ireq->request_daddr);
 531
 532         offset = phys_addr - ireq->request_daddr;
 533
 534         BUG_ON(offset >= sizeof(*ireq));
 535
 536         return (char *)ireq + offset;
 537 }
 538
 539 /* XXX open code in caller */
 540 static inline dma_addr_t
 541 scic_io_request_get_dma_addr(struct scic_sds_request *sci_req, void *virt_addr)
 542 {
 543         struct isci_request *ireq = sci_req_to_ireq(sci_req);
 544
 545         char *requested_addr = (char *)virt_addr;
 546         char *base_addr = (char *)ireq;
 547
 548         BUG_ON(requested_addr < base_addr);
 549         BUG_ON((requested_addr - base_addr) >= sizeof(*ireq));
 550
 551         return ireq->request_daddr + (requested_addr - base_addr);
 552 }
 553
 554 /**
 555  * This function gets the status of the request object.
 556  * @request: This parameter points to the isci_request object
 557  *
 558  * status of the object as a isci_request_status enum.
 559  */
 560 static inline enum isci_request_status
 561 isci_request_get_state(struct isci_request *isci_request)
 562 {
 563         BUG_ON(isci_request == NULL);
 564
 565         /*probably a bad sign...        */
 566         if (isci_request->status == unallocated)
 567                 dev_warn(&isci_request->isci_host->pdev->dev,
 568                          "%s: isci_request->status == unallocated\n",
 569                          __func__);
 570
 571         return isci_request->status;
 572 }
 573
 574
 575 /**
 576  * isci_request_change_state() - This function sets the status of the request
 577  *    object.
 578  * @request: This parameter points to the isci_request object
 579  * @status: This Parameter is the new status of the object
 580  *
 581  */
 582 static inline enum isci_request_status
 583 isci_request_change_state(struct isci_request *isci_request,
 584                           enum isci_request_status status)
 585 {
 586         enum isci_request_status old_state;
 587         unsigned long flags;
 588
 589         dev_dbg(&isci_request->isci_host->pdev->dev,
 590                 "%s: isci_request = %p, state = 0x%x\n",
 591                 __func__,
 592                 isci_request,
 593                 status);
 594
 595         BUG_ON(isci_request == NULL);
 596
 597         spin_lock_irqsave(&isci_request->state_lock, flags);
 598         old_state = isci_request->status;
 599         isci_request->status = status;
 600         spin_unlock_irqrestore(&isci_request->state_lock, flags);
 601
 602         return old_state;
 603 }
 604
 605 /**
 606  * isci_request_change_started_to_newstate() - This function sets the status of
 607  *    the request object.
 608  * @request: This parameter points to the isci_request object
 609  * @status: This Parameter is the new status of the object
 610  *
 611  * state previous to any change.
 612  */
 613 static inline enum isci_request_status
 614 isci_request_change_started_to_newstate(struct isci_request *isci_request,
 615                                         struct completion *completion_ptr,
 616                                         enum isci_request_status newstate)
 617 {
 618         enum isci_request_status old_state;
 619         unsigned long flags;
 620
 621         spin_lock_irqsave(&isci_request->state_lock, flags);
 622
 623         old_state = isci_request->status;
 624
 625         if (old_state == started || old_state == aborting) {
 626                 BUG_ON(isci_request->io_request_completion != NULL);
 627
 628                 isci_request->io_request_completion = completion_ptr;
 629                 isci_request->status = newstate;
 630         }
 631
 632         spin_unlock_irqrestore(&isci_request->state_lock, flags);
 633
 634         dev_dbg(&isci_request->isci_host->pdev->dev,
 635                 "%s: isci_request = %p, old_state = 0x%x\n",
 636                 __func__,
 637                 isci_request,
 638                 old_state);
 639
 640         return old_state;
 641 }
 642
 643 /**
 644  * isci_request_change_started_to_aborted() - This function sets the status of
 645  *    the request object.
 646  * @request: This parameter points to the isci_request object
 647  * @completion_ptr: This parameter is saved as the kernel completion structure
 648  *    signalled when the old request completes.
 649  *
 650  * state previous to any change.
 651  */
 652 static inline enum isci_request_status
 653 isci_request_change_started_to_aborted(struct isci_request *isci_request,
 654                                        struct completion *completion_ptr)
 655 {
 656         return isci_request_change_started_to_newstate(isci_request,
 657                                                        completion_ptr,
 658                                                        aborted);
 659 }
 660 /**
 661  * isci_request_free() - This function frees the request object.
 662  * @isci_host: This parameter specifies the ISCI host object
 663  * @isci_request: This parameter points to the isci_request object
 664  *
 665  */
 666 static inline void isci_request_free(struct isci_host *isci_host,
 667                                      struct isci_request *isci_request)
 668 {
 669         if (!isci_request)
 670                 return;
 671
 672         /* release the dma memory if we fail. */
 673         dma_pool_free(isci_host->dma_pool,
 674                       isci_request,
 675                       isci_request->request_daddr);
 676 }
 677
 678 #define isci_request_access_task(req) ((req)->ttype_ptr.io_task_ptr)
 679
 680 #define isci_request_access_tmf(req) ((req)->ttype_ptr.tmf_task_ptr)
 681
 682 int isci_request_alloc_tmf(struct isci_host *isci_host,
 683                            struct isci_tmf *isci_tmf,
 684                            struct isci_request **isci_request,
 685                            struct isci_remote_device *isci_device,
 686                            gfp_t gfp_flags);
 687
 688
 689 int isci_request_execute(struct isci_host *isci_host,
 690                          struct sas_task *task,
 691                          struct isci_request **request,
 692                          gfp_t gfp_flags);
 693
 694 /**
 695  * isci_request_unmap_sgl() - This function unmaps the DMA address of a given
 696  *    sgl
 697  * @request: This parameter points to the isci_request object
 698  * @*pdev: This Parameter is the pci_device struct for the controller
 699  *
 700  */
 701 static inline void
 702 isci_request_unmap_sgl(struct isci_request *request, struct pci_dev *pdev)
 703 {
 704         struct sas_task *task = isci_request_access_task(request);
 705
 706         dev_dbg(&request->isci_host->pdev->dev,
 707                 "%s: request = %p, task = %p,\n"
 708                 "task->data_dir = %d, is_sata = %d\n ",
 709                 __func__,
 710                 request,
 711                 task,
 712                 task->data_dir,
 713                 sas_protocol_ata(task->task_proto));
 714
 715         if ((task->data_dir != PCI_DMA_NONE) &&
 716             !sas_protocol_ata(task->task_proto)) {
 717                 if (task->num_scatter == 0)
 718                         /* 0 indicates a single dma address */
 719                         dma_unmap_single(
 720                                 &pdev->dev,
 721                                 request->zero_scatter_daddr,
 722                                 task->total_xfer_len,
 723                                 task->data_dir
 724                                 );
 725
 726                 else  /* unmap the sgl dma addresses */
 727                         dma_unmap_sg(
 728                                 &pdev->dev,
 729                                 task->scatter,
 730                                 request->num_sg_entries,
 731                                 task->data_dir
 732                                 );
 733         }
 734 }
 735
 736 /**
 737  * isci_request_io_request_get_next_sge() - This function is called by the sci
 738  *    core to retrieve the next sge for a given request.
 739  * @request: This parameter is the isci_request object.
 740  * @current_sge_address: This parameter is the last sge retrieved by the sci
 741  *    core for this request.
 742  *
 743  * pointer to the next sge for specified request.
 744  */
 745 static inline void *
 746 isci_request_io_request_get_next_sge(struct isci_request *request,
 747                                      void *current_sge_address)
 748 {
 749         struct sas_task *task = isci_request_access_task(request);
 750         void *ret = NULL;
 751
 752         dev_dbg(&request->isci_host->pdev->dev,
 753                 "%s: request = %p, "
 754                 "current_sge_address = %p, "
 755                 "num_scatter = %d\n",
 756                 __func__,
 757                 request,
 758                 current_sge_address,
 759                 task->num_scatter);
 760
 761         if (!current_sge_address)       /* First time through.. */
 762                 ret = task->scatter;    /* always task->scatter */
 763         else if (task->num_scatter == 0) /* Next element, if num_scatter == 0 */
 764                 ret = NULL;              /* there is only one element. */
 765         else
 766                 ret = sg_next(current_sge_address);     /* sg_next returns NULL
 767                                                          * for the last element
 768                                                          */
 769
 770         dev_dbg(&request->isci_host->pdev->dev,
 771                 "%s: next sge address = %p\n",
 772                 __func__,
 773                 ret);
 774
 775         return ret;
 776 }
 777
 778 void
 779 isci_terminate_pending_requests(struct isci_host *ihost,
 780                                 struct isci_remote_device *idev);
 781 enum sci_status
 782 scic_task_request_construct(struct scic_sds_controller *scic,
 783                             struct scic_sds_remote_device *sci_dev,
 784                             u16 io_tag,
 785                             struct scic_sds_request *sci_req);
 786 enum sci_status
 787 scic_task_request_construct_ssp(struct scic_sds_request *sci_req);
 788 enum sci_status
 789 scic_task_request_construct_sata(struct scic_sds_request *sci_req);
 790 void
 791 scic_stp_io_request_set_ncq_tag(struct scic_sds_request *sci_req, u16 ncq_tag);
 792 void scic_sds_smp_request_copy_response(struct scic_sds_request *sci_req);
 793 #endif /* !defined(_ISCI_REQUEST_H_) */