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From:   John Garry <john.garry@huawei.com>
To:     <jejb@linux.ibm.com>, <martin.petersen@oracle.com>,
        <jinpu.wang@cloud.ionos.com>, <damien.lemoal@wdc.com>
CC:     <hare@suse.de>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linuxarm@huawei.com>,
        <ipylypiv@google.com>, <changyuanl@google.com>,
        John Garry <john.garry@huawei.com>
Subject: [PATCH v4 3/7] scsi: hisi_sas: Put reserved tags in lower region of tagset
Date:   Tue, 18 Oct 2022 19:15:59 +0800
Message-ID: <1666091763-11023-4-git-send-email-john.garry@huawei.com>
In-Reply-To: <1666091763-11023-1-git-send-email-john.garry@huawei.com>
References: <1666091763-11023-1-git-send-email-john.garry@huawei.com>
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To be consistent with blk-mq, put the reserved tags in the lower region of
the tagset. Eventually we hope to get rid of all this reserved tag
management.

Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 26e474b0f53f..54860d252466 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -183,16 +183,16 @@ static int hisi_sas_slot_index_alloc(struct hisi_hba *hisi_hba,
 	void *bitmap = hisi_hba->slot_index_tags;
 
 	if (rq)
-		return rq->tag;
+		return rq->tag + HISI_SAS_RESERVED_IPTT;
 
 	spin_lock(&hisi_hba->lock);
-	index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count,
+	index = find_next_zero_bit(bitmap, HISI_SAS_RESERVED_IPTT,
 				   hisi_hba->last_slot_index + 1);
-	if (index >= hisi_hba->slot_index_count) {
+	if (index >= HISI_SAS_RESERVED_IPTT) {
 		index = find_next_zero_bit(bitmap,
-				hisi_hba->slot_index_count,
-				HISI_SAS_UNRESERVED_IPTT);
-		if (index >= hisi_hba->slot_index_count) {
+				HISI_SAS_RESERVED_IPTT,
+				0);
+		if (index >= HISI_SAS_RESERVED_IPTT) {
 			spin_unlock(&hisi_hba->lock);
 			return -SAS_QUEUE_FULL;
 		}
@@ -2216,7 +2216,7 @@ int hisi_sas_alloc(struct hisi_hba *hisi_hba)
 	if (!hisi_hba->sata_breakpoint)
 		goto err_out;
 
-	hisi_hba->last_slot_index = HISI_SAS_UNRESERVED_IPTT;
+	hisi_hba->last_slot_index = 0;
 
 	hisi_hba->wq = create_singlethread_workqueue(dev_name(dev));
 	if (!hisi_hba->wq) {
-- 
2.35.3