Commit e6c346f3 authored by John Garry's avatar John Garry Committed by Martin K. Petersen
Browse files

scsi: hisi_sas: save completion queue read pointer 



Optimise by saving an avoidable read in the cq interrupt.  The queue
read pointer will only be updated by software, so don't bother
re-reading what was already written in the previous interrupt.

Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent c4a11827

drivers/scsi/hisi_sas/hisi_sas.h

+1 −0
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ struct hisi_sas_port { 


struct hisi_sas_cq {

	struct hisi_hba *hisi_hba;

	int	rd_point;

	int	id;

};

drivers/scsi/hisi_sas/hisi_sas_v1_hw.c

+2 −4
Original line number Diff line number Diff line
@@ -1565,14 +1565,11 @@ static irqreturn_t cq_interrupt_v1_hw(int irq, void *p) 
	struct hisi_sas_complete_v1_hdr *complete_queue =

			(struct hisi_sas_complete_v1_hdr *)

			hisi_hba->complete_hdr[queue];

	u32 irq_value, rd_point, wr_point;

	u32 irq_value, rd_point = cq->rd_point, wr_point;



	irq_value = hisi_sas_read32(hisi_hba, OQ_INT_SRC);



	hisi_sas_write32(hisi_hba, OQ_INT_SRC, 1 << queue);



	rd_point = hisi_sas_read32(hisi_hba,

			COMPL_Q_0_RD_PTR + (0x14 * queue));

	wr_point = hisi_sas_read32(hisi_hba,

			COMPL_Q_0_WR_PTR + (0x14 * queue));
@@ -1600,6 +1597,7 @@ static irqreturn_t cq_interrupt_v1_hw(int irq, void *p) 
	}



	/* update rd_point */

	cq->rd_point = rd_point;

	hisi_sas_write32(hisi_hba, COMPL_Q_0_RD_PTR + (0x14 * queue), rd_point);



	return IRQ_HANDLED;

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

+2 −3
Original line number Diff line number Diff line
@@ -2049,7 +2049,7 @@ static irqreturn_t cq_interrupt_v2_hw(int irq_no, void *p) 
	struct hisi_sas_slot *slot;

	struct hisi_sas_itct *itct;

	struct hisi_sas_complete_v2_hdr *complete_queue;

	u32 irq_value, rd_point, wr_point, dev_id;

	u32 irq_value, rd_point = cq->rd_point, wr_point, dev_id;

	int queue = cq->id;



	complete_queue = hisi_hba->complete_hdr[queue];
@@ -2057,8 +2057,6 @@ static irqreturn_t cq_interrupt_v2_hw(int irq_no, void *p) 


	hisi_sas_write32(hisi_hba, OQ_INT_SRC, 1 << queue);



	rd_point = hisi_sas_read32(hisi_hba, COMPL_Q_0_RD_PTR +

				   (0x14 * queue));

	wr_point = hisi_sas_read32(hisi_hba, COMPL_Q_0_WR_PTR +

				   (0x14 * queue));
@@ -2106,6 +2104,7 @@ static irqreturn_t cq_interrupt_v2_hw(int irq_no, void *p) 
	}



	/* update rd_point */

	cq->rd_point = rd_point;

	hisi_sas_write32(hisi_hba, COMPL_Q_0_RD_PTR + (0x14 * queue), rd_point);

	return IRQ_HANDLED;

}