scsi: hisi_sas: Use block layer tag instead for IPTT

Currently we use the IPTT defined in LLDD to identify IOs. Actually for
IOs which are from the block layer, they have tags to identify them. So
for those IOs, use tag of the block layer directly, and for IOs which is
not from the block layer (such as internal IOs from libsas/LLDD), reserve
96 IPTTs for them.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 58 insertions, 31 deletions

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index a20bd6048e98..2e5eaf1a73a0 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -183,7 +183,14 @@ static void hisi_sas_slot_index_clear(struct hisi_hba *hisi_hba, int slot_idx)
 
 static void hisi_sas_slot_index_free(struct hisi_hba *hisi_hba, int slot_idx)
 {
-	hisi_sas_slot_index_clear(hisi_hba, slot_idx);
+	unsigned long flags;
+
+	if (hisi_hba->hw->slot_index_alloc || (slot_idx >=
+	    hisi_hba->hw->max_command_entries - HISI_SAS_RESERVED_IPTT_CNT)) {
+		spin_lock_irqsave(&hisi_hba->lock, flags);
+		hisi_sas_slot_index_clear(hisi_hba, slot_idx);
+		spin_unlock_irqrestore(&hisi_hba->lock, flags);
+	}
 }
 
 static void hisi_sas_slot_index_set(struct hisi_hba *hisi_hba, int slot_idx)
@@ -193,24 +200,34 @@ static void hisi_sas_slot_index_set(struct hisi_hba *hisi_hba, int slot_idx)
 	set_bit(slot_idx, bitmap);
 }
 
-static int hisi_sas_slot_index_alloc(struct hisi_hba *hisi_hba, int *slot_idx)
+static int hisi_sas_slot_index_alloc(struct hisi_hba *hisi_hba,
+				     struct scsi_cmnd *scsi_cmnd)
 {
-	unsigned int index;
+	int index;
 	void *bitmap = hisi_hba->slot_index_tags;
+	unsigned long flags;
 
+	if (scsi_cmnd)
+		return scsi_cmnd->request->tag;
+
+	spin_lock_irqsave(&hisi_hba->lock, flags);
 	index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count,
-			hisi_hba->last_slot_index + 1);
+				   hisi_hba->last_slot_index + 1);
 	if (index >= hisi_hba->slot_index_count) {
-		index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count,
-					   0);
-		if (index >= hisi_hba->slot_index_count)
+		index = find_next_zero_bit(bitmap,
+				hisi_hba->slot_index_count,
+				hisi_hba->hw->max_command_entries -
+				HISI_SAS_RESERVED_IPTT_CNT);
+		if (index >= hisi_hba->slot_index_count) {
+			spin_unlock_irqrestore(&hisi_hba->lock, flags);
 			return -SAS_QUEUE_FULL;
+		}
 	}
 	hisi_sas_slot_index_set(hisi_hba, index);
-	*slot_idx = index;
 	hisi_hba->last_slot_index = index;
+	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 
-	return 0;
+	return index;
 }
 
 static void hisi_sas_slot_index_init(struct hisi_hba *hisi_hba)
@@ -249,9 +266,7 @@ void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba, struct sas_task *task,
 
 	memset(slot, 0, offsetof(struct hisi_sas_slot, buf));
 
-	spin_lock_irqsave(&hisi_hba->lock, flags);
 	hisi_sas_slot_index_free(hisi_hba, slot->idx);
-	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 }
 EXPORT_SYMBOL_GPL(hisi_sas_slot_task_free);
 
@@ -384,16 +399,27 @@ static int hisi_sas_task_prep(struct sas_task *task,
 		goto err_out_dma_unmap;
 	}
 
-	spin_lock_irqsave(&hisi_hba->lock, flags);
 	if (hisi_hba->hw->slot_index_alloc)
-		rc = hisi_hba->hw->slot_index_alloc(hisi_hba, &slot_idx,
-						    device);
-	else
-		rc = hisi_sas_slot_index_alloc(hisi_hba, &slot_idx);
-	spin_unlock_irqrestore(&hisi_hba->lock, flags);
-	if (rc)
+		rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device);
+	else {
+		struct scsi_cmnd *scsi_cmnd = NULL;
+
+		if (task->uldd_task) {
+			struct ata_queued_cmd *qc;
+
+			if (dev_is_sata(device)) {
+				qc = task->uldd_task;
+				scsi_cmnd = qc->scsicmd;
+			} else {
+				scsi_cmnd = task->uldd_task;
+			}
+		}
+		rc  = hisi_sas_slot_index_alloc(hisi_hba, scsi_cmnd);
+	}
+	if (rc < 0)
 		goto err_out_dma_unmap;
 
+	slot_idx = rc;
 	slot = &hisi_hba->slot_info[slot_idx];
 
 	spin_lock_irqsave(&dq->lock, flags);
@@ -454,9 +480,7 @@ static int hisi_sas_task_prep(struct sas_task *task,
 	return 0;
 
 err_out_tag:
-	spin_lock_irqsave(&hisi_hba->lock, flags);
 	hisi_sas_slot_index_free(hisi_hba, slot_idx);
-	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 err_out_dma_unmap:
 	if (!sas_protocol_ata(task->task_proto)) {
 		if (task->num_scatter) {
@@ -1740,14 +1764,11 @@ hisi_sas_internal_abort_task_exec(struct hisi_hba *hisi_hba, int device_id,
 	port = to_hisi_sas_port(sas_port);
 
 	/* simply get a slot and send abort command */
-	spin_lock_irqsave(&hisi_hba->lock, flags);
-	rc = hisi_sas_slot_index_alloc(hisi_hba, &slot_idx);
-	if (rc) {
-		spin_unlock_irqrestore(&hisi_hba->lock, flags);
+	rc = hisi_sas_slot_index_alloc(hisi_hba, NULL);
+	if (rc < 0)
 		goto err_out;
-	}
-	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 
+	slot_idx = rc;
 	slot = &hisi_hba->slot_info[slot_idx];
 
 	spin_lock_irqsave(&dq->lock, flags_dq);
@@ -1783,7 +1804,6 @@ hisi_sas_internal_abort_task_exec(struct hisi_hba *hisi_hba, int device_id,
 	spin_lock_irqsave(&task->task_state_lock, flags);
 	task->task_state_flags |= SAS_TASK_AT_INITIATOR;
 	spin_unlock_irqrestore(&task->task_state_lock, flags);
-
 	WRITE_ONCE(slot->ready, 1);
 	/* send abort command to the chip */
 	spin_lock_irqsave(&dq->lock, flags);
@@ -1794,9 +1814,7 @@ hisi_sas_internal_abort_task_exec(struct hisi_hba *hisi_hba, int device_id,
 	return 0;
 
 err_out_tag:
-	spin_lock_irqsave(&hisi_hba->lock, flags);
 	hisi_sas_slot_index_free(hisi_hba, slot_idx);
-	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 err_out:
 	dev_err(dev, "internal abort task prep: failed[%d]!\n", rc);
 
@@ -2158,6 +2176,8 @@ int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost)
 	hisi_sas_init_mem(hisi_hba);
 
 	hisi_sas_slot_index_init(hisi_hba);
+	hisi_hba->last_slot_index = hisi_hba->hw->max_command_entries -
+		HISI_SAS_RESERVED_IPTT_CNT;
 
 	hisi_hba->wq = create_singlethread_workqueue(dev_name(dev));
 	if (!hisi_hba->wq) {
@@ -2361,8 +2381,15 @@ int hisi_sas_probe(struct platform_device *pdev,
 	shost->max_channel = 1;
 	shost->max_cmd_len = 16;
 	shost->sg_tablesize = min_t(u16, SG_ALL, HISI_SAS_SGE_PAGE_CNT);
-	shost->can_queue = hisi_hba->hw->max_command_entries;
-	shost->cmd_per_lun = hisi_hba->hw->max_command_entries;
+	if (hisi_hba->hw->slot_index_alloc) {
+		shost->can_queue = hisi_hba->hw->max_command_entries;
+		shost->cmd_per_lun = hisi_hba->hw->max_command_entries;
+	} else {
+		shost->can_queue = hisi_hba->hw->max_command_entries -
+			HISI_SAS_RESERVED_IPTT_CNT;
+		shost->cmd_per_lun = hisi_hba->hw->max_command_entries -
+			HISI_SAS_RESERVED_IPTT_CNT;
+	}
 
 	sha->sas_ha_name = DRV_NAME;
 	sha->dev = hisi_hba->dev;