xref: /openbmc/linux/drivers/scsi/isci/request.h (revision f139303d17c47eff4c5b5407dee0a6d43e8fd146)
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
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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  *
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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.
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43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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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 #include "stp_request.h"
63 
64 /**
65  * struct isci_request_status - This enum defines the possible states of an I/O
66  *    request.
67  *
68  *
69  */
70 enum isci_request_status {
71 	unallocated = 0x00,
72 	allocated   = 0x01,
73 	started     = 0x02,
74 	completed   = 0x03,
75 	aborting    = 0x04,
76 	aborted     = 0x05,
77 	terminating = 0x06,
78 	dead        = 0x07
79 };
80 
81 enum task_type {
82 	io_task  = 0,
83 	tmf_task = 1
84 };
85 
86 enum sci_request_protocol {
87 	SCIC_NO_PROTOCOL,
88 	SCIC_SMP_PROTOCOL,
89 	SCIC_SSP_PROTOCOL,
90 	SCIC_STP_PROTOCOL
91 }; /* XXX remove me, use sas_task.dev instead */;
92 
93 struct scic_sds_request {
94 	/**
95 	 * This field contains the information for the base request state machine.
96 	 */
97 	struct sci_base_state_machine state_machine;
98 
99 	/**
100 	 * This field simply points to the controller to which this IO request
101 	 * is associated.
102 	 */
103 	struct scic_sds_controller *owning_controller;
104 
105 	/**
106 	 * This field simply points to the remote device to which this IO request
107 	 * is associated.
108 	 */
109 	struct scic_sds_remote_device *target_device;
110 
111 	/**
112 	 * This field is utilized to determine if the SCI user is managing
113 	 * the IO tag for this request or if the core is managing it.
114 	 */
115 	bool was_tag_assigned_by_user;
116 
117 	/**
118 	 * This field indicates the IO tag for this request.  The IO tag is
119 	 * comprised of the task_index and a sequence count. The sequence count
120 	 * is utilized to help identify tasks from one life to another.
121 	 */
122 	u16 io_tag;
123 
124 	/**
125 	 * This field specifies the protocol being utilized for this
126 	 * IO request.
127 	 */
128 	enum sci_request_protocol protocol;
129 
130 	/**
131 	 * This field indicates the completion status taken from the SCUs
132 	 * completion code.  It indicates the completion result for the SCU hardware.
133 	 */
134 	u32 scu_status;
135 
136 	/**
137 	 * This field indicates the completion status returned to the SCI user.  It
138 	 * indicates the users view of the io request completion.
139 	 */
140 	u32 sci_status;
141 
142 	/**
143 	 * This field contains the value to be utilized when posting (e.g. Post_TC,
144 	 * Post_TC_Abort) this request to the silicon.
145 	 */
146 	u32 post_context;
147 
148 	struct scu_task_context *task_context_buffer;
149 	struct scu_task_context tc ____cacheline_aligned;
150 
151 	/* could be larger with sg chaining */
152 	#define SCU_SGL_SIZE ((SCU_IO_REQUEST_SGE_COUNT + 1) / 2)
153 	struct scu_sgl_element_pair sg_table[SCU_SGL_SIZE] __attribute__ ((aligned(32)));
154 
155 	/**
156 	 * This field indicates if this request is a task management request or
157 	 * normal IO request.
158 	 */
159 	bool is_task_management_request;
160 
161 	/**
162 	 * This field indicates that this request contains an initialized started
163 	 * substate machine.
164 	 */
165 	bool has_started_substate_machine;
166 
167 	/**
168 	 * This field is a pointer to the stored rx frame data.  It is used in STP
169 	 * internal requests and SMP response frames.  If this field is non-NULL the
170 	 * saved frame must be released on IO request completion.
171 	 *
172 	 * @todo In the future do we want to keep a list of RX frame buffers?
173 	 */
174 	u32 saved_rx_frame_index;
175 
176 	/**
177 	 * This field specifies the data necessary to manage the sub-state
178 	 * machine executed while in the SCI_BASE_REQUEST_STATE_STARTED state.
179 	 */
180 	struct sci_base_state_machine started_substate_machine;
181 
182 	/**
183 	 * This field specifies the current state handlers in place for this
184 	 * IO Request object.  This field is updated each time the request
185 	 * changes state.
186 	 */
187 	const struct scic_sds_io_request_state_handler *state_handlers;
188 
189 	/**
190 	 * This field in the recorded device sequence for the io request.  This is
191 	 * recorded during the build operation and is compared in the start
192 	 * operation.  If the sequence is different then there was a change of
193 	 * devices from the build to start operations.
194 	 */
195 	u8 device_sequence;
196 
197 	union {
198 		struct {
199 			union {
200 				struct ssp_cmd_iu cmd;
201 				struct ssp_task_iu tmf;
202 			};
203 			union {
204 				struct ssp_response_iu rsp;
205 				u8 rsp_buf[SSP_RESP_IU_MAX_SIZE];
206 			};
207 		} ssp;
208 
209 		struct {
210 			struct smp_req cmd;
211 			struct smp_resp rsp;
212 		} smp;
213 
214 		struct {
215 			struct scic_sds_stp_request req;
216 			struct host_to_dev_fis cmd;
217 			struct dev_to_host_fis rsp;
218 		} stp;
219 	};
220 
221 };
222 
223 static inline struct scic_sds_request *to_sci_req(struct scic_sds_stp_request *stp_req)
224 {
225 	struct scic_sds_request *sci_req;
226 
227 	sci_req = container_of(stp_req, typeof(*sci_req), stp.req);
228 	return sci_req;
229 }
230 
231 struct isci_request {
232 	enum isci_request_status status;
233 	enum task_type ttype;
234 	unsigned short io_tag;
235 	bool complete_in_target;
236 	bool terminated;
237 
238 	union ttype_ptr_union {
239 		struct sas_task *io_task_ptr;   /* When ttype==io_task  */
240 		struct isci_tmf *tmf_task_ptr;  /* When ttype==tmf_task */
241 	} ttype_ptr;
242 	struct isci_host *isci_host;
243 	struct isci_remote_device *isci_device;
244 	/* For use in the requests_to_{complete|abort} lists: */
245 	struct list_head completed_node;
246 	/* For use in the reqs_in_process list: */
247 	struct list_head dev_node;
248 	spinlock_t state_lock;
249 	dma_addr_t request_daddr;
250 	dma_addr_t zero_scatter_daddr;
251 
252 	unsigned int num_sg_entries;                    /* returned by pci_alloc_sg */
253 
254 	/** Note: "io_request_completion" is completed in two different ways
255 	 * depending on whether this is a TMF or regular request.
256 	 * - TMF requests are completed in the thread that started them;
257 	 * - regular requests are completed in the request completion callback
258 	 *   function.
259 	 * This difference in operation allows the aborter of a TMF request
260 	 * to be sure that once the TMF request completes, the I/O that the
261 	 * TMF was aborting is guaranteed to have completed.
262 	 */
263 	struct completion *io_request_completion;
264 	struct scic_sds_request sci;
265 };
266 
267 static inline struct isci_request *sci_req_to_ireq(struct scic_sds_request *sci_req)
268 {
269 	struct isci_request *ireq = container_of(sci_req, typeof(*ireq), sci);
270 
271 	return ireq;
272 }
273 
274 /**
275  * enum sci_base_request_states - This enumeration depicts all the states for
276  *    the common request state machine.
277  *
278  *
279  */
280 enum sci_base_request_states {
281 	/**
282 	 * Simply the initial state for the base request state machine.
283 	 */
284 	SCI_BASE_REQUEST_STATE_INITIAL,
285 
286 	/**
287 	 * This state indicates that the request has been constructed. This state
288 	 * is entered from the INITIAL state.
289 	 */
290 	SCI_BASE_REQUEST_STATE_CONSTRUCTED,
291 
292 	/**
293 	 * This state indicates that the request has been started. This state is
294 	 * entered from the CONSTRUCTED state.
295 	 */
296 	SCI_BASE_REQUEST_STATE_STARTED,
297 
298 	/**
299 	 * The AWAIT_TC_COMPLETION sub-state indicates that the started raw
300 	 * task management request is waiting for the transmission of the
301 	 * initial frame (i.e. command, task, etc.).
302 	 */
303 	SCIC_SDS_IO_REQUEST_STARTED_TASK_MGMT_SUBSTATE_AWAIT_TC_COMPLETION,
304 
305 	/**
306 	 * This sub-state indicates that the started task management request
307 	 * is waiting for the reception of an unsolicited frame
308 	 * (i.e. response IU).
309 	 */
310 	SCIC_SDS_IO_REQUEST_STARTED_TASK_MGMT_SUBSTATE_AWAIT_TC_RESPONSE,
311 
312 	/**
313 	 * This state indicates that the request has completed.
314 	 * This state is entered from the STARTED state. This state is entered from
315 	 * the ABORTING state.
316 	 */
317 	SCI_BASE_REQUEST_STATE_COMPLETED,
318 
319 	/**
320 	 * This state indicates that the request is in the process of being
321 	 * terminated/aborted.
322 	 * This state is entered from the CONSTRUCTED state.
323 	 * This state is entered from the STARTED state.
324 	 */
325 	SCI_BASE_REQUEST_STATE_ABORTING,
326 
327 	/**
328 	 * Simply the final state for the base request state machine.
329 	 */
330 	SCI_BASE_REQUEST_STATE_FINAL,
331 };
332 
333 typedef enum sci_status (*scic_sds_io_request_handler_t)
334 				(struct scic_sds_request *request);
335 typedef enum sci_status (*scic_sds_io_request_frame_handler_t)
336 				(struct scic_sds_request *req, u32 frame);
337 typedef enum sci_status (*scic_sds_io_request_event_handler_t)
338 				(struct scic_sds_request *req, u32 event);
339 typedef enum sci_status (*scic_sds_io_request_task_completion_handler_t)
340 				(struct scic_sds_request *req, u32 completion_code);
341 
342 /**
343  * struct scic_sds_io_request_state_handler - This is the SDS core definition
344  *    of the state handlers.
345  *
346  *
347  */
348 struct scic_sds_io_request_state_handler {
349 	/**
350 	 * The start_handler specifies the method invoked when a user attempts to
351 	 * start a request.
352 	 */
353 	scic_sds_io_request_handler_t start_handler;
354 
355 	/**
356 	 * The abort_handler specifies the method invoked when a user attempts to
357 	 * abort a request.
358 	 */
359 	scic_sds_io_request_handler_t abort_handler;
360 
361 	/**
362 	 * The complete_handler specifies the method invoked when a user attempts to
363 	 * complete a request.
364 	 */
365 	scic_sds_io_request_handler_t complete_handler;
366 
367 	scic_sds_io_request_task_completion_handler_t tc_completion_handler;
368 	scic_sds_io_request_event_handler_t event_handler;
369 	scic_sds_io_request_frame_handler_t frame_handler;
370 
371 };
372 
373 extern const struct sci_base_state scic_sds_io_request_started_task_mgmt_substate_table[];
374 
375 /**
376  * scic_sds_request_get_controller() -
377  *
378  * This macro will return the controller for this io request object
379  */
380 #define scic_sds_request_get_controller(sci_req) \
381 	((sci_req)->owning_controller)
382 
383 /**
384  * scic_sds_request_get_device() -
385  *
386  * This macro will return the device for this io request object
387  */
388 #define scic_sds_request_get_device(sci_req) \
389 	((sci_req)->target_device)
390 
391 /**
392  * scic_sds_request_get_port() -
393  *
394  * This macro will return the port for this io request object
395  */
396 #define scic_sds_request_get_port(sci_req)	\
397 	scic_sds_remote_device_get_port(scic_sds_request_get_device(sci_req))
398 
399 /**
400  * scic_sds_request_get_post_context() -
401  *
402  * This macro returns the constructed post context result for the io request.
403  */
404 #define scic_sds_request_get_post_context(sci_req)	\
405 	((sci_req)->post_context)
406 
407 /**
408  * scic_sds_request_get_task_context() -
409  *
410  * This is a helper macro to return the os handle for this request object.
411  */
412 #define scic_sds_request_get_task_context(request) \
413 	((request)->task_context_buffer)
414 
415 /**
416  * scic_sds_request_set_status() -
417  *
418  * This macro will set the scu hardware status and sci request completion
419  * status for an io request.
420  */
421 #define scic_sds_request_set_status(request, scu_status_code, sci_status_code) \
422 	{ \
423 		(request)->scu_status = (scu_status_code); \
424 		(request)->sci_status = (sci_status_code); \
425 	}
426 
427 #define scic_sds_request_complete(a_request) \
428 	((a_request)->state_handlers->complete_handler(a_request))
429 
430 
431 extern enum sci_status
432 scic_sds_io_request_tc_completion(struct scic_sds_request *request, u32 completion_code);
433 
434 /**
435  * SCU_SGL_ZERO() -
436  *
437  * This macro zeros the hardware SGL element data
438  */
439 #define SCU_SGL_ZERO(scu_sge) \
440 	{ \
441 		(scu_sge).length = 0; \
442 		(scu_sge).address_lower = 0; \
443 		(scu_sge).address_upper = 0; \
444 		(scu_sge).address_modifier = 0;	\
445 	}
446 
447 /**
448  * SCU_SGL_COPY() -
449  *
450  * This macro copys the SGL Element data from the host os to the hardware SGL
451  * elment data
452  */
453 #define SCU_SGL_COPY(scu_sge, os_sge) \
454 	{ \
455 		(scu_sge).length = sg_dma_len(sg); \
456 		(scu_sge).address_upper = \
457 			upper_32_bits(sg_dma_address(sg)); \
458 		(scu_sge).address_lower = \
459 			lower_32_bits(sg_dma_address(sg)); \
460 		(scu_sge).address_modifier = 0;	\
461 	}
462 
463 void scic_sds_request_build_sgl(struct scic_sds_request *sci_req);
464 void scic_sds_stp_request_assign_buffers(struct scic_sds_request *sci_req);
465 void scic_sds_smp_request_assign_buffers(struct scic_sds_request *sci_req);
466 enum sci_status scic_sds_request_start(struct scic_sds_request *sci_req);
467 enum sci_status scic_sds_io_request_terminate(struct scic_sds_request *sci_req);
468 enum sci_status scic_sds_io_request_event_handler(struct scic_sds_request *sci_req,
469 						  u32 event_code);
470 enum sci_status scic_sds_io_request_frame_handler(struct scic_sds_request *sci_req,
471 						  u32 frame_index);
472 enum sci_status scic_sds_task_request_terminate(struct scic_sds_request *sci_req);
473 enum sci_status scic_sds_request_started_state_abort_handler(struct scic_sds_request *sci_req);
474 
475 
476 /**
477  * enum _scic_sds_smp_request_started_substates - This enumeration depicts all
478  *    of the substates for a SMP request to be performed in the STARTED
479  *    super-state.
480  *
481  *
482  */
483 enum scic_sds_smp_request_started_substates {
484 	/**
485 	 * This sub-state indicates that the started task management request
486 	 * is waiting for the reception of an unsolicited frame
487 	 * (i.e. response IU).
488 	 */
489 	SCIC_SDS_SMP_REQUEST_STARTED_SUBSTATE_AWAIT_RESPONSE,
490 
491 	/**
492 	 * The AWAIT_TC_COMPLETION sub-state indicates that the started SMP request is
493 	 * waiting for the transmission of the initial frame (i.e. command, task, etc.).
494 	 */
495 	SCIC_SDS_SMP_REQUEST_STARTED_SUBSTATE_AWAIT_TC_COMPLETION,
496 };
497 
498 
499 
500 /* XXX open code in caller */
501 static inline void *scic_request_get_virt_addr(struct scic_sds_request *sci_req,
502 					       dma_addr_t phys_addr)
503 {
504 	struct isci_request *ireq = sci_req_to_ireq(sci_req);
505 	dma_addr_t offset;
506 
507 	BUG_ON(phys_addr < ireq->request_daddr);
508 
509 	offset = phys_addr - ireq->request_daddr;
510 
511 	BUG_ON(offset >= sizeof(*ireq));
512 
513 	return (char *)ireq + offset;
514 }
515 
516 /* XXX open code in caller */
517 static inline dma_addr_t scic_io_request_get_dma_addr(struct scic_sds_request *sci_req,
518 						      void *virt_addr)
519 {
520 	struct isci_request *ireq = sci_req_to_ireq(sci_req);
521 
522 	char *requested_addr = (char *)virt_addr;
523 	char *base_addr = (char *)ireq;
524 
525 	BUG_ON(requested_addr < base_addr);
526 	BUG_ON((requested_addr - base_addr) >= sizeof(*ireq));
527 
528 	return ireq->request_daddr + (requested_addr - base_addr);
529 }
530 
531 /**
532  * This function gets the status of the request object.
533  * @request: This parameter points to the isci_request object
534  *
535  * status of the object as a isci_request_status enum.
536  */
537 static inline
538 enum isci_request_status isci_request_get_state(
539 	struct isci_request *isci_request)
540 {
541 	BUG_ON(isci_request == NULL);
542 
543 	/*probably a bad sign...	*/
544 	if (isci_request->status == unallocated)
545 		dev_warn(&isci_request->isci_host->pdev->dev,
546 			 "%s: isci_request->status == unallocated\n",
547 			 __func__);
548 
549 	return isci_request->status;
550 }
551 
552 
553 /**
554  * isci_request_change_state() - This function sets the status of the request
555  *    object.
556  * @request: This parameter points to the isci_request object
557  * @status: This Parameter is the new status of the object
558  *
559  */
560 static inline enum isci_request_status isci_request_change_state(
561 	struct isci_request *isci_request,
562 	enum isci_request_status status)
563 {
564 	enum isci_request_status old_state;
565 	unsigned long flags;
566 
567 	dev_dbg(&isci_request->isci_host->pdev->dev,
568 		"%s: isci_request = %p, state = 0x%x\n",
569 		__func__,
570 		isci_request,
571 		status);
572 
573 	BUG_ON(isci_request == NULL);
574 
575 	spin_lock_irqsave(&isci_request->state_lock, flags);
576 	old_state = isci_request->status;
577 	isci_request->status = status;
578 	spin_unlock_irqrestore(&isci_request->state_lock, flags);
579 
580 	return old_state;
581 }
582 
583 /**
584  * isci_request_change_started_to_newstate() - This function sets the status of
585  *    the request object.
586  * @request: This parameter points to the isci_request object
587  * @status: This Parameter is the new status of the object
588  *
589  * state previous to any change.
590  */
591 static inline enum isci_request_status isci_request_change_started_to_newstate(
592 	struct isci_request *isci_request,
593 	struct completion *completion_ptr,
594 	enum isci_request_status newstate)
595 {
596 	enum isci_request_status old_state;
597 	unsigned long flags;
598 
599 	spin_lock_irqsave(&isci_request->state_lock, flags);
600 
601 	old_state = isci_request->status;
602 
603 	if (old_state == started || old_state == aborting) {
604 		BUG_ON(isci_request->io_request_completion != NULL);
605 
606 		isci_request->io_request_completion = completion_ptr;
607 		isci_request->status = newstate;
608 	}
609 	spin_unlock_irqrestore(&isci_request->state_lock, flags);
610 
611 	dev_dbg(&isci_request->isci_host->pdev->dev,
612 		"%s: isci_request = %p, old_state = 0x%x\n",
613 		__func__,
614 		isci_request,
615 		old_state);
616 
617 	return old_state;
618 }
619 
620 /**
621  * isci_request_change_started_to_aborted() - This function sets the status of
622  *    the request object.
623  * @request: This parameter points to the isci_request object
624  * @completion_ptr: This parameter is saved as the kernel completion structure
625  *    signalled when the old request completes.
626  *
627  * state previous to any change.
628  */
629 static inline enum isci_request_status isci_request_change_started_to_aborted(
630 	struct isci_request *isci_request,
631 	struct completion *completion_ptr)
632 {
633 	return isci_request_change_started_to_newstate(
634 		       isci_request, completion_ptr, aborted
635 		       );
636 }
637 /**
638  * isci_request_free() - This function frees the request object.
639  * @isci_host: This parameter specifies the ISCI host object
640  * @isci_request: This parameter points to the isci_request object
641  *
642  */
643 static inline void isci_request_free(
644 	struct isci_host *isci_host,
645 	struct isci_request *isci_request)
646 {
647 	if (!isci_request)
648 		return;
649 
650 	/* release the dma memory if we fail. */
651 	dma_pool_free(isci_host->dma_pool, isci_request,
652 		      isci_request->request_daddr);
653 }
654 
655 
656 /* #define ISCI_REQUEST_VALIDATE_ACCESS
657  */
658 
659 #ifdef ISCI_REQUEST_VALIDATE_ACCESS
660 
661 static inline
662 struct sas_task *isci_request_access_task(struct isci_request *isci_request)
663 {
664 	BUG_ON(isci_request->ttype != io_task);
665 	return isci_request->ttype_ptr.io_task_ptr;
666 }
667 
668 static inline
669 struct isci_tmf *isci_request_access_tmf(struct isci_request *isci_request)
670 {
671 	BUG_ON(isci_request->ttype != tmf_task);
672 	return isci_request->ttype_ptr.tmf_task_ptr;
673 }
674 
675 #else  /* not ISCI_REQUEST_VALIDATE_ACCESS */
676 
677 #define isci_request_access_task(RequestPtr) \
678 	((RequestPtr)->ttype_ptr.io_task_ptr)
679 
680 #define isci_request_access_tmf(RequestPtr)  \
681 	((RequestPtr)->ttype_ptr.tmf_task_ptr)
682 
683 #endif /* not ISCI_REQUEST_VALIDATE_ACCESS */
684 
685 
686 int isci_request_alloc_tmf(
687 	struct isci_host *isci_host,
688 	struct isci_tmf *isci_tmf,
689 	struct isci_request **isci_request,
690 	struct isci_remote_device *isci_device,
691 	gfp_t gfp_flags);
692 
693 
694 int isci_request_execute(
695 	struct isci_host *isci_host,
696 	struct sas_task *task,
697 	struct isci_request **request,
698 	gfp_t gfp_flags);
699 
700 /**
701  * isci_request_unmap_sgl() - This function unmaps the DMA address of a given
702  *    sgl
703  * @request: This parameter points to the isci_request object
704  * @*pdev: This Parameter is the pci_device struct for the controller
705  *
706  */
707 static inline void isci_request_unmap_sgl(
708 	struct isci_request *request,
709 	struct pci_dev *pdev)
710 {
711 	struct sas_task *task = isci_request_access_task(request);
712 
713 	dev_dbg(&request->isci_host->pdev->dev,
714 		"%s: request = %p, task = %p,\n"
715 		"task->data_dir = %d, is_sata = %d\n ",
716 		__func__,
717 		request,
718 		task,
719 		task->data_dir,
720 		sas_protocol_ata(task->task_proto));
721 
722 	if ((task->data_dir != PCI_DMA_NONE) &&
723 	    !sas_protocol_ata(task->task_proto)) {
724 		if (task->num_scatter == 0)
725 			/* 0 indicates a single dma address */
726 			dma_unmap_single(
727 				&pdev->dev,
728 				request->zero_scatter_daddr,
729 				task->total_xfer_len,
730 				task->data_dir
731 				);
732 
733 		else  /* unmap the sgl dma addresses */
734 			dma_unmap_sg(
735 				&pdev->dev,
736 				task->scatter,
737 				request->num_sg_entries,
738 				task->data_dir
739 				);
740 	}
741 }
742 
743 /**
744  * isci_request_io_request_get_next_sge() - This function is called by the sci
745  *    core to retrieve the next sge for a given request.
746  * @request: This parameter is the isci_request object.
747  * @current_sge_address: This parameter is the last sge retrieved by the sci
748  *    core for this request.
749  *
750  * pointer to the next sge for specified request.
751  */
752 static inline void *isci_request_io_request_get_next_sge(
753 	struct isci_request *request,
754 	void *current_sge_address)
755 {
756 	struct sas_task *task = isci_request_access_task(request);
757 	void *ret = NULL;
758 
759 	dev_dbg(&request->isci_host->pdev->dev,
760 		"%s: request = %p, "
761 		"current_sge_address = %p, "
762 		"num_scatter = %d\n",
763 		__func__,
764 		request,
765 		current_sge_address,
766 		task->num_scatter);
767 
768 	if (!current_sge_address)	/* First time through.. */
769 		ret = task->scatter;    /* always task->scatter */
770 	else if (task->num_scatter == 0) /* Next element, if num_scatter == 0 */
771 		ret = NULL;              /* there is only one element. */
772 	else
773 		ret = sg_next(current_sge_address);     /* sg_next returns NULL
774 							 * for the last element
775 							 */
776 
777 	dev_dbg(&request->isci_host->pdev->dev,
778 		"%s: next sge address = %p\n",
779 		__func__,
780 		ret);
781 
782 	return ret;
783 }
784 
785 void isci_terminate_pending_requests(struct isci_host *isci_host,
786 				     struct isci_remote_device *isci_device,
787 				     enum isci_request_status new_request_state);
788 enum sci_status scic_task_request_construct(struct scic_sds_controller *scic,
789 					    struct scic_sds_remote_device *sci_dev,
790 					    u16 io_tag,
791 					    struct scic_sds_request *sci_req);
792 enum sci_status scic_task_request_construct_ssp(struct scic_sds_request *sci_req);
793 enum sci_status scic_task_request_construct_sata(struct scic_sds_request *sci_req);
794 enum sci_status scic_io_request_construct_smp(struct scic_sds_request *sci_req);
795 void scic_stp_io_request_set_ncq_tag(struct scic_sds_request *sci_req, u16 ncq_tag);
796 void scic_sds_smp_request_copy_response(struct scic_sds_request *sci_req);
797 #endif /* !defined(_ISCI_REQUEST_H_) */
798