Commit 66ea9bcc authored by Uma Krishnan's avatar Uma Krishnan Committed by Martin K. Petersen
Browse files

scsi: cxlflash: Combine the send queue locks 



Currently there are separate spin locks for the two supported I/O queueing
models. This makes it difficult to serialize with paths outside the enqueue
path.

As a design simplification and to support serialization with enqueue
operations, move to only a single lock that is used for enqueueing
regardless of the queueing model.

Signed-off-by: default avatarUma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d31b7791

drivers/scsi/cxlflash/common.h

+1 −2
Original line number Diff line number Diff line
@@ -193,7 +193,7 @@ struct hwq { 
	u32 index;		/* Index of this hwq */



	atomic_t hsq_credits;

	spinlock_t hsq_slock;

	spinlock_t hsq_slock;	/* Hardware send queue lock */

	struct sisl_ioarcb *hsq_start;

	struct sisl_ioarcb *hsq_end;

	struct sisl_ioarcb *hsq_curr;
@@ -204,7 +204,6 @@ struct hwq { 
	bool toggle;



	s64 room;

	spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */



	struct irq_poll irqpoll;

} __aligned(cache_line_size());

drivers/scsi/cxlflash/main.c

+5 −4
Original line number Diff line number Diff line
@@ -261,7 +261,7 @@ static int send_cmd_ioarrin(struct afu *afu, struct afu_cmd *cmd) 
	 * To avoid the performance penalty of MMIO, spread the update of

	 * 'room' over multiple commands.

	 */

	spin_lock_irqsave(&hwq->rrin_slock, lock_flags);

	spin_lock_irqsave(&hwq->hsq_slock, lock_flags);

	if (--hwq->room < 0) {

		room = readq_be(&hwq->host_map->cmd_room);

		if (room <= 0) {
@@ -277,7 +277,7 @@ static int send_cmd_ioarrin(struct afu *afu, struct afu_cmd *cmd) 


	writeq_be((u64)&cmd->rcb, &hwq->host_map->ioarrin);

out:

	spin_unlock_irqrestore(&hwq->rrin_slock, lock_flags);

	spin_unlock_irqrestore(&hwq->hsq_slock, lock_flags);

	dev_dbg(dev, "%s: cmd=%p len=%u ea=%016llx rc=%d\n", __func__,

		cmd, cmd->rcb.data_len, cmd->rcb.data_ea, rc);

	return rc;
@@ -1722,7 +1722,10 @@ static int start_afu(struct cxlflash_cfg *cfg) 
		hwq->hrrq_end = &hwq->rrq_entry[NUM_RRQ_ENTRY - 1];

		hwq->hrrq_curr = hwq->hrrq_start;

		hwq->toggle = 1;



		/* Initialize spin locks */

		spin_lock_init(&hwq->hrrq_slock);

		spin_lock_init(&hwq->hsq_slock);



		/* Initialize SQ */

		if (afu_is_sq_cmd_mode(afu)) {
@@ -1731,7 +1734,6 @@ static int start_afu(struct cxlflash_cfg *cfg) 
			hwq->hsq_end = &hwq->sq[NUM_SQ_ENTRY - 1];

			hwq->hsq_curr = hwq->hsq_start;



			spin_lock_init(&hwq->hsq_slock);

			atomic_set(&hwq->hsq_credits, NUM_SQ_ENTRY - 1);

		}
@@ -1984,7 +1986,6 @@ static int init_afu(struct cxlflash_cfg *cfg) 
	for (i = 0; i < afu->num_hwqs; i++) {

		hwq = get_hwq(afu, i);



		spin_lock_init(&hwq->rrin_slock);

		hwq->room = readq_be(&hwq->host_map->cmd_room);

	}

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