scic_controller.h 27.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _SCIC_CONTROLLER_H_
#define _SCIC_CONTROLLER_H_

/**
 * This file contains all of the interface methods that can be called by an
 *    SCIC user on a controller object.
 *
 *
 */


#include "sci_types.h"
#include "sci_status.h"
#include "sci_controller.h"
#include "scic_config_parameters.h"

struct scic_sds_request;
struct scic_sds_phy;
struct scic_sds_port;
struct scic_sds_remote_device;

/**
 * enum _SCIC_INTERRUPT_TYPE - This enumeration depicts the various types of
 *    interrupts that are potentially supported by a SCI Core implementation.
 *
 *
 */
enum scic_interrupt_type {
	SCIC_LEGACY_LINE_INTERRUPT_TYPE,
	SCIC_MSIX_INTERRUPT_TYPE,

	/**
	 * This enumeration value indicates the use of polling.
	 */
	SCIC_NO_INTERRUPTS

};

/**
 * This method is called by the SCI user in order to have the SCI
 *    implementation handle the interrupt.  This method performs minimal
 *    processing to allow for streamlined interrupt time usage.
 *
 * SCIC_CONTROLLER_INTERRUPT_HANDLER true: returned if there is an interrupt to
 * process and it was processed. false: returned if no interrupt was processed.
 */
typedef bool (*SCIC_CONTROLLER_INTERRUPT_HANDLER)(
	struct scic_sds_controller *controller
	);

/**
 * This method is called by the SCI user to process completions generated as a
 *    result of a previously handled interrupt.  This method will result in the
 *    completion of IO requests and handling of other controller generated
 *    events.  This method should be called some time after the interrupt
 *    handler.
 *
 * Most, if not all, of the user callback APIs are invoked from within this
 * API.  As a result, the user should be cognizent of the operating level at
 * which they invoke this API.
 */
typedef void (*SCIC_CONTROLLER_COMPLETION_HANDLER)(
	struct scic_sds_controller *controller
	);

/**
 * struct scic_controller_handler_methods - This structure contains an
 *    interrupt handler and completion handler function pointers.
 *
 *
 */
struct scic_controller_handler_methods {
	SCIC_CONTROLLER_INTERRUPT_HANDLER interrupt_handler;
	SCIC_CONTROLLER_COMPLETION_HANDLER completion_handler;

};

/**
 * scic_controller_construct() - This method will attempt to construct a
 *    controller object utilizing the supplied parameter information.
 * @c: This parameter specifies the controller to be constructed.
 * @scu_base: mapped base address of the scu registers
 * @smu_base: mapped base address of the smu registers
 *
 * Indicate if the controller was successfully constructed or if it failed in
 * some way. SCI_SUCCESS This value is returned if the controller was
 * successfully constructed. SCI_WARNING_TIMER_CONFLICT This value is returned
 * if the interrupt coalescence timer may cause SAS compliance issues for SMP
 * Target mode response processing. SCI_FAILURE_UNSUPPORTED_CONTROLLER_TYPE
 * This value is returned if the controller does not support the supplied type.
 * SCI_FAILURE_UNSUPPORTED_INIT_DATA_VERSION This value is returned if the
 * controller does not support the supplied initialization data version.
 */
enum sci_status scic_controller_construct(struct scic_sds_controller *c,
					  void __iomem *scu_base,
					  void __iomem *smu_base);

/**
 * scic_controller_enable_interrupts() - This method will enable all controller
 *    interrupts.
 * @controller: This parameter specifies the controller for which to enable
 *    interrupts.
 *
 */
void scic_controller_enable_interrupts(
	struct scic_sds_controller *controller);

/**
 * scic_controller_disable_interrupts() - This method will disable all
 *    controller interrupts.
 * @controller: This parameter specifies the controller for which to disable
 *    interrupts.
 *
 */
void scic_controller_disable_interrupts(
	struct scic_sds_controller *controller);

/**
 * scic_controller_get_handler_methods() - This method will return provide
 *    function pointers for the interrupt handler and completion handler.  The
 *    interrupt handler is expected to be invoked at interrupt time.  The
 *    completion handler is scheduled to run as a result of the interrupt
 *    handler. The completion handler performs the bulk work for processing
 *    silicon events.
 * @interrupt_type: This parameter informs the core which type of
 *    interrupt/completion methods are being requested. These are the types:
 *    SCIC_LEGACY_LINE_INTERRUPT_TYPE, SCIC_MSIX_INTERRUPT_TYPE,
 *    SCIC_NO_INTERRUPTS (POLLING)
 * @message_count: This parameter informs the core the number of MSI-X messages
 *    to be utilized.  This parameter must be 0 when requesting legacy line
 *    based handlers.
 * @handler_methods: The caller provides a pointer to a buffer of type
 *    struct scic_controller_handler_methods. The size depends on the combination of
 *    the interrupt_type and message_count input parameters:
 *    SCIC_LEGACY_LINE_INTERRUPT_TYPE: - size =
 *    sizeof(struct scic_controller_handler_methods) SCIC_MSIX_INTERRUPT_TYPE:
 *    sizeof(struct scic_controller_handler_methods)
 * @handler_methods: SCIC fills out the caller's buffer with the appropriate
 *    interrupt and completion handlers based on the info provided in the
 *    interrupt_type and message_count input parameters. For
 *    SCIC_LEGACY_LINE_INTERRUPT_TYPE, the buffer receives a single
 *    struct scic_controller_handler_methods element regardless that the
 *    message_count parameter is zero. For SCIC_MSIX_INTERRUPT_TYPE, the buffer
 *    receives an array of elements of type struct scic_controller_handler_methods
 *    where the array size is equivalent to the message_count parameter. The
 *    array is zero-relative where entry zero corresponds to message-vector
 *    zero, entry one corresponds to message-vector one, and so forth.
 *
 * Indicate if the handler retrieval operation was successful. SCI_SUCCESS This
 * value is returned if retrieval succeeded.
 * SCI_FAILURE_UNSUPPORTED_MESSAGE_COUNT This value is returned if the user
 * supplied an unsupported number of MSI-X messages. For legacy line interrupts
 * the only valid value is 0.
 */
enum sci_status scic_controller_get_handler_methods(
	enum scic_interrupt_type interrupt_type,
	u16 message_count,
	struct scic_controller_handler_methods *handler_methods);

/**
 * scic_controller_initialize() - This method will initialize the controller
 *    hardware managed by the supplied core controller object.  This method
 *    will bring the physical controller hardware out of reset and enable the
 *    core to determine the capabilities of the hardware being managed.  Thus,
 *    the core controller can determine it's exact physical (DMA capable)
 *    memory requirements.
 * @controller: This parameter specifies the controller to be initialized.
 *
 * The SCI Core user must have called scic_controller_construct() on the
 * supplied controller object previously. Indicate if the controller was
 * successfully initialized or if it failed in some way. SCI_SUCCESS This value
 * is returned if the controller hardware was successfully initialized.
 */
enum sci_status scic_controller_initialize(
	struct scic_sds_controller *controller);

/**
 * scic_controller_get_suggested_start_timeout() - This method returns the
 *    suggested scic_controller_start() timeout amount.  The user is free to
 *    use any timeout value, but this method provides the suggested minimum
 *    start timeout value.  The returned value is based upon empirical
 *    information determined as a result of interoperability testing.
 * @controller: the handle to the controller object for which to return the
 *    suggested start timeout.
 *
 * This method returns the number of milliseconds for the suggested start
 * operation timeout.
 */
u32 scic_controller_get_suggested_start_timeout(
	struct scic_sds_controller *controller);

/**
 * scic_controller_start() - This method will start the supplied core
 *    controller.  This method will start the staggered spin up operation.  The
 *    SCI User completion callback is called when the following conditions are
 *    met: -# the return status of this method is SCI_SUCCESS. -# after all of
 *    the phys have successfully started or been given the opportunity to start.
 * @controller: the handle to the controller object to start.
 * @timeout: This parameter specifies the number of milliseconds in which the
 *    start operation should complete.
 *
 * The SCI Core user must have filled in the physical memory descriptor
 * structure via the sci_controller_get_memory_descriptor_list() method. The
 * SCI Core user must have invoked the scic_controller_initialize() method
 * prior to invoking this method. The controller must be in the INITIALIZED or
 * STARTED state. Indicate if the controller start method succeeded or failed
 * in some way. SCI_SUCCESS if the start operation succeeded.
 * SCI_WARNING_ALREADY_IN_STATE if the controller is already in the STARTED
 * state. SCI_FAILURE_INVALID_STATE if the controller is not either in the
 * INITIALIZED or STARTED states. SCI_FAILURE_INVALID_MEMORY_DESCRIPTOR if
 * there are inconsistent or invalid values in the supplied
 * struct sci_physical_memory_descriptor array.
 */
enum sci_status scic_controller_start(
	struct scic_sds_controller *controller,
	u32 timeout);

/**
 * scic_controller_stop() - This method will stop an individual controller
 *    object.This method will invoke the associated user callback upon
 *    completion.  The completion callback is called when the following
 *    conditions are met: -# the method return status is SCI_SUCCESS. -# the
 *    controller has been quiesced. This method will ensure that all IO
 *    requests are quiesced, phys are stopped, and all additional operation by
 *    the hardware is halted.
 * @controller: the handle to the controller object to stop.
 * @timeout: This parameter specifies the number of milliseconds in which the
 *    stop operation should complete.
 *
 * The controller must be in the STARTED or STOPPED state. Indicate if the
 * controller stop method succeeded or failed in some way. SCI_SUCCESS if the
 * stop operation successfully began. SCI_WARNING_ALREADY_IN_STATE if the
 * controller is already in the STOPPED state. SCI_FAILURE_INVALID_STATE if the
 * controller is not either in the STARTED or STOPPED states.
 */
enum sci_status scic_controller_stop(
	struct scic_sds_controller *controller,
	u32 timeout);

/**
 * scic_controller_reset() - This method will reset the supplied core
 *    controller regardless of the state of said controller.  This operation is
 *    considered destructive.  In other words, all current operations are wiped
 *    out.  No IO completions for outstanding devices occur.  Outstanding IO
 *    requests are not aborted or completed at the actual remote device.
 * @controller: the handle to the controller object to reset.
 *
 * Indicate if the controller reset method succeeded or failed in some way.
 * SCI_SUCCESS if the reset operation successfully started. SCI_FATAL_ERROR if
 * the controller reset operation is unable to complete.
 */
enum sci_status scic_controller_reset(
	struct scic_sds_controller *controller);

/**
 * scic_controller_start_io() - This method is called by the SCI user to
 *    send/start an IO request. If the method invocation is successful, then
 *    the IO request has been queued to the hardware for processing.
 * @controller: the handle to the controller object for which to start an IO
 *    request.
 * @remote_device: the handle to the remote device object for which to start an
 *    IO request.
 * @io_request: the handle to the io request object to start.
 * @io_tag: This parameter specifies a previously allocated IO tag that the
 *    user desires to be utilized for this request. This parameter is optional.
 *     The user is allowed to supply SCI_CONTROLLER_INVALID_IO_TAG as the value
 *    for this parameter.
 *
 * - IO tags are a protected resource.  It is incumbent upon the SCI Core user
 * to ensure that each of the methods that may allocate or free available IO
 * tags are handled in a mutually exclusive manner.  This method is one of said
 * methods requiring proper critical code section protection (e.g. semaphore,
 * spin-lock, etc.). - For SATA, the user is required to manage NCQ tags.  As a
 * result, it is expected the user will have set the NCQ tag field in the host
 * to device register FIS prior to calling this method.  There is also a
 * requirement for the user to call scic_stp_io_set_ncq_tag() prior to invoking
 * the scic_controller_start_io() method. scic_controller_allocate_tag() for
 * more information on allocating a tag. Indicate if the controller
 * successfully started the IO request. SCI_IO_SUCCESS if the IO request was
 * successfully started. Determine the failure situations and return values.
 */
enum sci_io_status scic_controller_start_io(
	struct scic_sds_controller *controller,
	struct scic_sds_remote_device *remote_device,
	struct scic_sds_request *io_request,
	u16 io_tag);


/**
 * scic_controller_start_task() - This method is called by the SCIC user to
 *    send/start a framework task management request.
 * @controller: the handle to the controller object for which to start the task
 *    management request.
 * @remote_device: the handle to the remote device object for which to start
 *    the task management request.
 * @task_request: the handle to the task request object to start.
 * @io_tag: This parameter specifies a previously allocated IO tag that the
 *    user desires to be utilized for this request.  Note this not the io_tag
 *    of the request being managed.  It is to be utilized for the task request
 *    itself. This parameter is optional.  The user is allowed to supply
 *    SCI_CONTROLLER_INVALID_IO_TAG as the value for this parameter.
 *
 * - IO tags are a protected resource.  It is incumbent upon the SCI Core user
 * to ensure that each of the methods that may allocate or free available IO
 * tags are handled in a mutually exclusive manner.  This method is one of said
 * methods requiring proper critical code section protection (e.g. semaphore,
 * spin-lock, etc.). - The user must synchronize this task with completion
 * queue processing.  If they are not synchronized then it is possible for the
 * io requests that are being managed by the task request can complete before
 * starting the task request. scic_controller_allocate_tag() for more
 * information on allocating a tag. Indicate if the controller successfully
 * started the IO request. SCI_TASK_SUCCESS if the task request was
 * successfully started. SCI_TASK_FAILURE_REQUIRES_SCSI_ABORT This value is
 * returned if there is/are task(s) outstanding that require termination or
 * completion before this request can succeed.
 */
enum sci_task_status scic_controller_start_task(
	struct scic_sds_controller *controller,
	struct scic_sds_remote_device *remote_device,
	struct scic_sds_request *task_request,
	u16 io_tag);

/**
 * scic_controller_complete_task() - This method will perform core specific
 *    completion operations for task management request. After this method is
 *    invoked, the user should consider the task request as invalid until it is
 *    properly reused (i.e. re-constructed).
 * @controller: The handle to the controller object for which to complete the
 *    task management request.
 * @remote_device: The handle to the remote device object for which to complete
 *    the task management request.
 * @task_request: the handle to the task management request object to complete.
 *
 * Indicate if the controller successfully completed the task management
 * request. SCI_SUCCESS if the completion process was successful.
 */
enum sci_status scic_controller_complete_task(
	struct scic_sds_controller *controller,
	struct scic_sds_remote_device *remote_device,
	struct scic_sds_request *task_request);


/**
 * scic_controller_terminate_request() - This method is called by the SCI Core
 *    user to terminate an ongoing (i.e. started) core IO request.  This does
 *    not abort the IO request at the target, but rather removes the IO request
 *    from the host controller.
 * @controller: the handle to the controller object for which to terminate a
 *    request.
 * @remote_device: the handle to the remote device object for which to
 *    terminate a request.
 * @request: the handle to the io or task management request object to
 *    terminate.
 *
 * Indicate if the controller successfully began the terminate process for the
 * IO request. SCI_SUCCESS if the terminate process was successfully started
 * for the request. Determine the failure situations and return values.
 */
enum sci_status scic_controller_terminate_request(
	struct scic_sds_controller *controller,
	struct scic_sds_remote_device *remote_device,
	struct scic_sds_request *request);

/**
 * scic_controller_complete_io() - This method will perform core specific
 *    completion operations for an IO request.  After this method is invoked,
 *    the user should consider the IO request as invalid until it is properly
 *    reused (i.e. re-constructed).
 * @controller: The handle to the controller object for which to complete the
 *    IO request.
 * @remote_device: The handle to the remote device object for which to complete
 *    the IO request.
 * @io_request: the handle to the io request object to complete.
 *
 * - IO tags are a protected resource.  It is incumbent upon the SCI Core user
 * to ensure that each of the methods that may allocate or free available IO
 * tags are handled in a mutually exclusive manner.  This method is one of said
 * methods requiring proper critical code section protection (e.g. semaphore,
 * spin-lock, etc.). - If the IO tag for a request was allocated, by the SCI
 * Core user, using the scic_controller_allocate_io_tag() method, then it is
 * the responsibility of the caller to invoke the scic_controller_free_io_tag()
 * method to free the tag (i.e. this method will not free the IO tag). Indicate
 * if the controller successfully completed the IO request. SCI_SUCCESS if the
 * completion process was successful.
 */
enum sci_status scic_controller_complete_io(
	struct scic_sds_controller *controller,
	struct scic_sds_remote_device *remote_device,
	struct scic_sds_request *io_request);


/**
 * scic_controller_get_port_handle() - This method simply provides the user
 *    with a unique handle for a given SAS/SATA core port index.
 * @controller: This parameter represents the handle to the controller object
 *    from which to retrieve a port (SAS or SATA) handle.
 * @port_index: This parameter specifies the port index in the controller for
 *    which to retrieve the port handle. 0 <= port_index < maximum number of
 *    phys.
 * @port_handle: This parameter specifies the retrieved port handle to be
 *    provided to the caller.
 *
 * Indicate if the retrieval of the port handle was successful. SCI_SUCCESS
 * This value is returned if the retrieval was successful.
 * SCI_FAILURE_INVALID_PORT This value is returned if the supplied port id is
 * not in the supported range.
 */
enum sci_status scic_controller_get_port_handle(
	struct scic_sds_controller *controller,
	u8 port_index,
	struct scic_sds_port **port_handle);

/**
 * scic_controller_get_phy_handle() - This method simply provides the user with
 *    a unique handle for a given SAS/SATA phy index/identifier.
 * @controller: This parameter represents the handle to the controller object
 *    from which to retrieve a phy (SAS or SATA) handle.
 * @phy_index: This parameter specifies the phy index in the controller for
 *    which to retrieve the phy handle. 0 <= phy_index < maximum number of phys.
 * @phy_handle: This parameter specifies the retrieved phy handle to be
 *    provided to the caller.
 *
 * Indicate if the retrieval of the phy handle was successful. SCI_SUCCESS This
 * value is returned if the retrieval was successful. SCI_FAILURE_INVALID_PHY
 * This value is returned if the supplied phy id is not in the supported range.
 */
enum sci_status scic_controller_get_phy_handle(
	struct scic_sds_controller *controller,
	u8 phy_index,
	struct scic_sds_phy **phy_handle);

/**
 * scic_controller_allocate_io_tag() - This method will allocate a tag from the
 *    pool of free IO tags. Direct allocation of IO tags by the SCI Core user
 *    is optional. The scic_controller_start_io() method will allocate an IO
 *    tag if this method is not utilized and the tag is not supplied to the IO
 *    construct routine.  Direct allocation of IO tags may provide additional
 *    performance improvements in environments capable of supporting this usage
 *    model.  Additionally, direct allocation of IO tags also provides
 *    additional flexibility to the SCI Core user.  Specifically, the user may
 *    retain IO tags across the lives of multiple IO requests.
 * @controller: the handle to the controller object for which to allocate the
 *    tag.
 *
 * IO tags are a protected resource.  It is incumbent upon the SCI Core user to
 * ensure that each of the methods that may allocate or free available IO tags
 * are handled in a mutually exclusive manner.  This method is one of said
 * methods requiring proper critical code section protection (e.g. semaphore,
 * spin-lock, etc.). An unsigned integer representing an available IO tag.
 * SCI_CONTROLLER_INVALID_IO_TAG This value is returned if there are no
 * currently available tags to be allocated. All return other values indicate a
 * legitimate tag.
 */
u16 scic_controller_allocate_io_tag(
	struct scic_sds_controller *controller);

/**
 * scic_controller_free_io_tag() - This method will free an IO tag to the pool
 *    of free IO tags. This method provides the SCI Core user more flexibility
 *    with regards to IO tags.  The user may desire to keep an IO tag after an
 *    IO request has completed, because they plan on re-using the tag for a
 *    subsequent IO request.  This method is only legal if the tag was
 *    allocated via scic_controller_allocate_io_tag().
 * @controller: This parameter specifies the handle to the controller object
 *    for which to free/return the tag.
 * @io_tag: This parameter represents the tag to be freed to the pool of
 *    available tags.
 *
 * - IO tags are a protected resource.  It is incumbent upon the SCI Core user
 * to ensure that each of the methods that may allocate or free available IO
 * tags are handled in a mutually exclusive manner.  This method is one of said
 * methods requiring proper critical code section protection (e.g. semaphore,
 * spin-lock, etc.). - If the IO tag for a request was allocated, by the SCI
 * Core user, using the scic_controller_allocate_io_tag() method, then it is
 * the responsibility of the caller to invoke this method to free the tag. This
 * method returns an indication of whether the tag was successfully put back
 * (freed) to the pool of available tags. SCI_SUCCESS This return value
 * indicates the tag was successfully placed into the pool of available IO
 * tags. SCI_FAILURE_INVALID_IO_TAG This value is returned if the supplied tag
 * is not a valid IO tag value.
 */
enum sci_status scic_controller_free_io_tag(
	struct scic_sds_controller *controller,
	u16 io_tag);




/**
 * scic_controller_set_mode() - This method allows the user to configure the
 *    SCI core into either a performance mode or a memory savings mode.
 * @controller: This parameter represents the handle to the controller object
 *    for which to update the operating mode.
 * @mode: This parameter specifies the new mode for the controller.
 *
 * Indicate if the user successfully change the operating mode of the
 * controller. SCI_SUCCESS The user successfully updated the mode.
 */
enum sci_status scic_controller_set_mode(
	struct scic_sds_controller *controller,
	enum sci_controller_mode mode);


/**
 * scic_controller_set_interrupt_coalescence() - This method allows the user to
 *    configure the interrupt coalescence.
 * @controller: This parameter represents the handle to the controller object
 *    for which its interrupt coalesce register is overridden.
 * @coalesce_number: Used to control the number of entries in the Completion
 *    Queue before an interrupt is generated. If the number of entries exceed
 *    this number, an interrupt will be generated. The valid range of the input
 *    is [0, 256]. A setting of 0 results in coalescing being disabled.
 * @coalesce_timeout: Timeout value in microseconds. The valid range of the
 *    input is [0, 2700000] . A setting of 0 is allowed and results in no
 *    interrupt coalescing timeout.
 *
 * Indicate if the user successfully set the interrupt coalesce parameters.
 * SCI_SUCCESS The user successfully updated the interrutp coalescence.
 * SCI_FAILURE_INVALID_PARAMETER_VALUE The user input value is out of range.
 */
enum sci_status scic_controller_set_interrupt_coalescence(
	struct scic_sds_controller *controller,
	u32 coalesce_number,
	u32 coalesce_timeout);

struct device;
struct scic_sds_controller *scic_controller_alloc(struct device *dev);


#endif  /* _SCIC_CONTROLLER_H_ */