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>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -34,6 +34,7 @@
 #define HISI_SAS_MAX_DEVICES HISI_SAS_MAX_ITCT_ENTRIES
 #define HISI_SAS_RESET_BIT	0
 #define HISI_SAS_REJECT_CMD_BIT	1
+#define HISI_SAS_RESERVED_IPTT_CNT  96
 
 #define HISI_SAS_STATUS_BUF_SZ (sizeof(struct hisi_sas_status_buffer))
 #define HISI_SAS_COMMAND_TABLE_SZ (sizeof(union hisi_sas_command_table))
@@ -217,7 +218,7 @@ struct hisi_sas_hw {
 	int (*hw_init)(struct hisi_hba *hisi_hba);
 	void (*setup_itct)(struct hisi_hba *hisi_hba,
 			   struct hisi_sas_device *device);
-	int (*slot_index_alloc)(struct hisi_hba *hisi_hba, int *slot_idx,
+	int (*slot_index_alloc)(struct hisi_hba *hisi_hba,
 				struct domain_device *device);
 	struct hisi_sas_device *(*alloc_dev)(struct domain_device *device);
 	void (*sl_notify)(struct hisi_hba *hisi_hba, int phy_no);

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;

drivers/scsi/hisi_sas/hisi_sas_v1_hw.c

@@ -1809,7 +1809,6 @@ static struct scsi_host_template sht_v1_hw = {
 	.scan_start		= hisi_sas_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
 	.bios_param		= sas_bios_param,
-	.can_queue		= 1,
 	.this_id		= -1,
 	.sg_tablesize		= SG_ALL,
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

@@ -770,7 +770,7 @@ static u32 hisi_sas_phy_read32(struct hisi_hba *hisi_hba,
 
 /* This function needs to be protected from pre-emption. */
 static int
-slot_index_alloc_quirk_v2_hw(struct hisi_hba *hisi_hba, int *slot_idx,
+slot_index_alloc_quirk_v2_hw(struct hisi_hba *hisi_hba,
 			     struct domain_device *device)
 {
 	int sata_dev = dev_is_sata(device);
@@ -778,6 +778,7 @@ slot_index_alloc_quirk_v2_hw(struct hisi_hba *hisi_hba, int *slot_idx,
 	struct hisi_sas_device *sas_dev = device->lldd_dev;
 	int sata_idx = sas_dev->sata_idx;
 	int start, end;
+	unsigned long flags;
 
 	if (!sata_dev) {
 		/*
@@ -801,6 +802,7 @@ slot_index_alloc_quirk_v2_hw(struct hisi_hba *hisi_hba, int *slot_idx,
 		end = 64 * (sata_idx + 2);
 	}
 
+	spin_lock_irqsave(&hisi_hba->lock, flags);
 	while (1) {
 		start = find_next_zero_bit(bitmap,
 					hisi_hba->slot_index_count, start);
@@ -815,8 +817,8 @@ slot_index_alloc_quirk_v2_hw(struct hisi_hba *hisi_hba, int *slot_idx,
 	}
 
 	set_bit(start, bitmap);
-	*slot_idx = start;
-	return 0;
+	spin_unlock_irqrestore(&hisi_hba->lock, flags);
+	return start;
 }
 
 static bool sata_index_alloc_v2_hw(struct hisi_hba *hisi_hba, int *idx)
@@ -3560,7 +3562,6 @@ static struct scsi_host_template sht_v2_hw = {
 	.scan_start		= hisi_sas_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
 	.bios_param		= sas_bios_param,
-	.can_queue		= 1,
 	.this_id		= -1,
 	.sg_tablesize		= SG_ALL,
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -2098,7 +2098,6 @@ static struct scsi_host_template sht_v3_hw = {
 	.scan_start		= hisi_sas_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
 	.bios_param		= sas_bios_param,
-	.can_queue		= 1,
 	.this_id		= -1,
 	.sg_tablesize		= SG_ALL,
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
@@ -2108,6 +2107,7 @@ static struct scsi_host_template sht_v3_hw = {
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
 	.shost_attrs		= host_attrs,
+	.tag_alloc_policy	= BLK_TAG_ALLOC_RR,
 };
 
 static const struct hisi_sas_hw hisi_sas_v3_hw = {
@@ -2245,8 +2245,10 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	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;
+	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 = dev;