Commit 994a9303 authored by Dan Williams's avatar Dan Williams
Browse files

isci: cleanup/optimize queue increment macros 



Every single i/o or event completion incurs a test and branch to see if
the cycle bit changed.  For power-of-2 queue sizes the cycle bit can be
read directly from the rollover of the queue pointer.

Likely premature optimization, but the hidden if() and hidden
assignments / side-effects in the macros were already asking to be
cleaned up.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent dd047c8e

drivers/scsi/isci/host.c

+13 −43
Original line number Diff line number Diff line
@@ -122,34 +122,6 @@ 
		>> SMU_COMPLETION_QUEUE_GET_EVENT_POINTER_SHIFT	\

	)



/**

 * INCREMENT_COMPLETION_QUEUE_GET() -

 *

 * This macro will increment the controllers completion queue index value and

 * possibly toggle the cycle bit if the completion queue index wraps back to 0.

 */

#define INCREMENT_COMPLETION_QUEUE_GET(controller, index, cycle) \

	INCREMENT_QUEUE_GET(\

		(index), \

		(cycle), \

		SCU_MAX_COMPLETION_QUEUE_ENTRIES, \

		SMU_CQGR_CYCLE_BIT)



/**

 * INCREMENT_EVENT_QUEUE_GET() -

 *

 * This macro will increment the controllers event queue index value and

 * possibly toggle the event cycle bit if the event queue index wraps back to 0.

 */

#define INCREMENT_EVENT_QUEUE_GET(controller, index, cycle) \

	INCREMENT_QUEUE_GET(\

		(index), \

		(cycle), \

		SCU_MAX_EVENTS, \

		SMU_CQGR_EVENT_CYCLE_BIT \

		)





/**

 * NORMALIZE_GET_POINTER() -

 *
@@ -528,15 +500,13 @@ static void scic_sds_controller_event_completion(struct scic_sds_controller *sci 
	}

}







static void scic_sds_controller_process_completions(struct scic_sds_controller *scic)

{

	u32 completion_count = 0;

	u32 completion_entry;

	u32 get_index;

	u32 get_cycle;

	u32 event_index;

	u32 event_get;

	u32 event_cycle;



	dev_dbg(scic_to_dev(scic),
@@ -548,7 +518,7 @@ static void scic_sds_controller_process_completions(struct scic_sds_controller * 
	get_index = NORMALIZE_GET_POINTER(scic->completion_queue_get);

	get_cycle = SMU_CQGR_CYCLE_BIT & scic->completion_queue_get;



	event_index = NORMALIZE_EVENT_POINTER(scic->completion_queue_get);

	event_get = NORMALIZE_EVENT_POINTER(scic->completion_queue_get);

	event_cycle = SMU_CQGR_EVENT_CYCLE_BIT & scic->completion_queue_get;



	while (
@@ -558,7 +528,11 @@ static void scic_sds_controller_process_completions(struct scic_sds_controller * 
		completion_count++;



		completion_entry = scic->completion_queue[get_index];

		INCREMENT_COMPLETION_QUEUE_GET(scic, get_index, get_cycle);



		/* increment the get pointer and check for rollover to toggle the cycle bit */

		get_cycle ^= ((get_index+1) & SCU_MAX_COMPLETION_QUEUE_ENTRIES) <<

			     (SMU_COMPLETION_QUEUE_GET_CYCLE_BIT_SHIFT - SCU_MAX_COMPLETION_QUEUE_SHIFT);

		get_index = (get_index+1) & (SCU_MAX_COMPLETION_QUEUE_ENTRIES-1);



		dev_dbg(scic_to_dev(scic),

			"%s: completion queue entry:0x%08x\n",
@@ -579,18 +553,14 @@ static void scic_sds_controller_process_completions(struct scic_sds_controller * 
			break;



		case SCU_COMPLETION_TYPE_EVENT:

			INCREMENT_EVENT_QUEUE_GET(scic, event_index, event_cycle);

			scic_sds_controller_event_completion(scic, completion_entry);

			break;

		case SCU_COMPLETION_TYPE_NOTIFY: {

			event_cycle ^= ((event_get+1) & SCU_MAX_EVENTS) <<

				       (SMU_COMPLETION_QUEUE_GET_EVENT_CYCLE_BIT_SHIFT - SCU_MAX_EVENTS_SHIFT);

			event_get = (event_get+1) & (SCU_MAX_EVENTS-1);



		case SCU_COMPLETION_TYPE_NOTIFY:

			/*

			 * Presently we do the same thing with a notify event that we do with the

			 * other event codes. */

			INCREMENT_EVENT_QUEUE_GET(scic, event_index, event_cycle);

			scic_sds_controller_event_completion(scic, completion_entry);

			break;



		}

		default:

			dev_warn(scic_to_dev(scic),

				 "%s: SCIC Controller received unknown "
@@ -607,7 +577,7 @@ static void scic_sds_controller_process_completions(struct scic_sds_controller * 
			SMU_CQGR_GEN_BIT(ENABLE) |

			SMU_CQGR_GEN_BIT(EVENT_ENABLE) |

			event_cycle |

			SMU_CQGR_GEN_VAL(EVENT_POINTER, event_index) |

			SMU_CQGR_GEN_VAL(EVENT_POINTER, event_get) |

			get_cycle |

			SMU_CQGR_GEN_VAL(POINTER, get_index);

drivers/scsi/isci/host.h

+0 −16
Original line number Diff line number Diff line
@@ -523,22 +523,6 @@ static inline struct isci_host *scic_to_ihost(struct scic_sds_controller *scic) 
	return ihost;

}



/**

 * INCREMENT_QUEUE_GET() -

 *

 * This macro will increment the specified index to and if the index wraps to 0

 * it will toggel the cycle bit.

 */

#define INCREMENT_QUEUE_GET(index, cycle, entry_count, bit_toggle) \

	{ \

		if ((index) + 1 == entry_count) {	\

			(index) = 0; \

			(cycle) = (cycle) ^ (bit_toggle); \

		} else { \

			index = index + 1; \

		} \

	}



/**

 * scic_sds_controller_get_protocol_engine_group() -

 *

drivers/scsi/isci/isci.h

+3 −1
Original line number Diff line number Diff line
@@ -90,7 +90,8 @@ enum sci_controller_mode { 
#define SCI_MAX_DOMAINS  SCI_MAX_PORTS



#define SCU_MAX_CRITICAL_NOTIFICATIONS    (384)

#define SCU_MAX_EVENTS                    (128)

#define SCU_MAX_EVENTS_SHIFT		  (7)

#define SCU_MAX_EVENTS                    (1 << SCU_MAX_EVENTS_SHIFT)

#define SCU_MAX_UNSOLICITED_FRAMES        (128)

#define SCU_MAX_COMPLETION_QUEUE_SCRATCH  (128)

#define SCU_MAX_COMPLETION_QUEUE_ENTRIES  (SCU_MAX_CRITICAL_NOTIFICATIONS \
@@ -98,6 +99,7 @@ enum sci_controller_mode { 
					   + SCU_MAX_UNSOLICITED_FRAMES	\

					   + SCI_MAX_IO_REQUESTS \

					   + SCU_MAX_COMPLETION_QUEUE_SCRATCH)

#define SCU_MAX_COMPLETION_QUEUE_SHIFT	  (ilog2(SCU_MAX_COMPLETION_QUEUE_ENTRIES))



#define SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES (4096)

#define SCU_UNSOLICITED_FRAME_BUFFER_SIZE   (1024)

drivers/scsi/isci/unsolicited_frame_control.c

+28 −30
Original line number Diff line number Diff line
@@ -209,7 +209,8 @@ bool scic_sds_unsolicited_frame_control_release_frame( 
	/*

	 * In the event there are NULL entries in the UF table, we need to

	 * advance the get pointer in order to find out if this frame should

	 * be released (i.e. update the get pointer). */

	 * be released (i.e. update the get pointer)

	 */

	while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&

	       upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&

	       frame_get < SCU_MAX_UNSOLICITED_FRAMES)
@@ -217,40 +218,37 @@ bool scic_sds_unsolicited_frame_control_release_frame( 


	/*

	 * The table has a NULL entry as it's last element.  This is

	 * illegal. */

	 * illegal.

	 */

	BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);

	if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)

		return false;



	if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {

	uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;



	if (frame_get != frame_index) {

		/*

		 * Frames remain in use until we advance the get pointer

		 * so there is nothing we can do here

		 */

		return false;

	}



	/*

	 * The frame index is equal to the current get pointer so we

		 * can now free up all of the frame entries that */

		if (frame_get == frame_index) {

			while (

				uf_control->buffers.array[frame_get].state

				== UNSOLICITED_FRAME_RELEASED

				) {

	 * can now free up all of the frame entries that

	 */

	while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {

		uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;



				INCREMENT_QUEUE_GET(

					frame_get,

					frame_cycle,

					SCU_MAX_UNSOLICITED_FRAMES - 1,

					SCU_MAX_UNSOLICITED_FRAMES);

		if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {

			frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;

			frame_get = 0;

		} else

			frame_get++;

	}



			uf_control->get =

				(SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get);

	uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;



	return true;

		} else {

			/*

			 * Frames remain in use until we advance the get pointer

			 * so there is nothing we can do here */

		}

}
 


	return false;

}

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