scsi: ufs: core: Prepare ufshcd_send_command() for MCQ

Add support to send commands using multiple submission queues in MCQ mode.
Modify the functions that use ufshcd_send_command().

Co-developed-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Can Guo <quic_cang@quicinc.com>
Signed-off-by: Asutosh Das <quic_asutoshd@quicinc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufs-mcq.c

@@ -309,6 +309,7 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
 	for (i = 0; i < hba->nr_hw_queues; i++) {
 		hwq = &hba->uhq[i];
 		hwq->max_entries = hba->nutrs;
+		spin_lock_init(&hwq->sq_lock);
 	}
 
 	/* The very first HW queue serves device commands */

drivers/ufs/core/ufshcd-priv.h

@@ -335,4 +335,14 @@ static inline bool ufs_is_valid_unit_desc_lun(struct ufs_dev_info *dev_info, u8
 	return lun == UFS_UPIU_RPMB_WLUN || (lun < dev_info->max_lu_supported);
 }
 
+static inline void ufshcd_inc_sq_tail(struct ufs_hw_queue *q)
+{
+	u32 mask = q->max_entries - 1;
+	u32 val;
+
+	q->sq_tail_slot = (q->sq_tail_slot + 1) & mask;
+	val = q->sq_tail_slot * sizeof(struct utp_transfer_req_desc);
+	writel(val, q->mcq_sq_tail);
+}
+
 #endif /* _UFSHCD_PRIV_H_ */

drivers/ufs/core/ufshcd.c

@@ -2185,9 +2185,11 @@ static void ufshcd_update_monitor(struct ufs_hba *hba, const struct ufshcd_lrb *
  * ufshcd_send_command - Send SCSI or device management commands
  * @hba: per adapter instance
  * @task_tag: Task tag of the command
+ * @hwq: pointer to hardware queue instance
  */
 static inline
-void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
+void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag,
+			 struct ufs_hw_queue *hwq)
 {
 	struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
 	unsigned long flags;
@@ -2201,12 +2203,24 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
 	if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
 		ufshcd_start_monitor(hba, lrbp);
 
-	spin_lock_irqsave(&hba->outstanding_lock, flags);
-	if (hba->vops && hba->vops->setup_xfer_req)
-		hba->vops->setup_xfer_req(hba, task_tag, !!lrbp->cmd);
-	__set_bit(task_tag, &hba->outstanding_reqs);
-	ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
-	spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+	if (is_mcq_enabled(hba)) {
+		int utrd_size = sizeof(struct utp_transfer_req_desc);
+
+		spin_lock(&hwq->sq_lock);
+		memcpy(hwq->sqe_base_addr + (hwq->sq_tail_slot * utrd_size),
+		       lrbp->utr_descriptor_ptr, utrd_size);
+		ufshcd_inc_sq_tail(hwq);
+		spin_unlock(&hwq->sq_lock);
+	} else {
+		spin_lock_irqsave(&hba->outstanding_lock, flags);
+		if (hba->vops && hba->vops->setup_xfer_req)
+			hba->vops->setup_xfer_req(hba, lrbp->task_tag,
+						  !!lrbp->cmd);
+		__set_bit(lrbp->task_tag, &hba->outstanding_reqs);
+		ufshcd_writel(hba, 1 << lrbp->task_tag,
+			      REG_UTP_TRANSFER_REQ_DOOR_BELL);
+		spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+	}
 }
 
 /**
@@ -2836,6 +2850,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 	int tag = scsi_cmd_to_rq(cmd)->tag;
 	struct ufshcd_lrb *lrbp;
 	int err = 0;
+	struct ufs_hw_queue *hwq = NULL;
 
 	WARN_ONCE(tag < 0 || tag >= hba->nutrs, "Invalid tag %d\n", tag);
 
@@ -2920,7 +2935,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		goto out;
 	}
 
-	ufshcd_send_command(hba, tag);
+	ufshcd_send_command(hba, tag, hwq);
 
 out:
 	rcu_read_unlock();
@@ -3121,10 +3136,11 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
 		goto out;
 
 	hba->dev_cmd.complete = &wait;
+	hba->dev_cmd.cqe = NULL;
 
 	ufshcd_add_query_upiu_trace(hba, UFS_QUERY_SEND, lrbp->ucd_req_ptr);
 
-	ufshcd_send_command(hba, tag);
+	ufshcd_send_command(hba, tag, hba->dev_cmd_queue);
 	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
 	ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR : UFS_QUERY_COMP,
 				    (struct utp_upiu_req *)lrbp->ucd_rsp_ptr);
@@ -6938,7 +6954,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
 
 	ufshcd_add_query_upiu_trace(hba, UFS_QUERY_SEND, lrbp->ucd_req_ptr);
 
-	ufshcd_send_command(hba, tag);
+	ufshcd_send_command(hba, tag, hba->dev_cmd_queue);
 	/*
 	 * ignore the returning value here - ufshcd_check_query_response is
 	 * bound to fail since dev_cmd.query and dev_cmd.type were left empty.
@@ -7104,7 +7120,7 @@ int ufshcd_advanced_rpmb_req_handler(struct ufs_hba *hba, struct utp_upiu_req *r
 
 	hba->dev_cmd.complete = &wait;
 
-	ufshcd_send_command(hba, tag);
+	ufshcd_send_command(hba, tag, hba->dev_cmd_queue);
 
 	err = ufshcd_wait_for_dev_cmd(hba, lrbp, ADVANCED_RPMB_REQ_TIMEOUT);
 

include/ufs/ufshcd.h

@@ -224,6 +224,7 @@ struct ufs_dev_cmd {
 	struct mutex lock;
 	struct completion *complete;
 	struct ufs_query query;
+	struct cq_entry *cqe;
 };
 
 /**
@@ -1078,6 +1079,8 @@ struct ufs_hba {
  * @cqe_dma_addr: completion queue dma address
  * @max_entries: max number of slots in this hardware queue
  * @id: hardware queue ID
+ * @sq_tp_slot: current slot to which SQ tail pointer is pointing
+ * @sq_lock: serialize submission queue access
  */
 struct ufs_hw_queue {
 	void __iomem *mcq_sq_head;
@@ -1091,6 +1094,8 @@ struct ufs_hw_queue {
 	dma_addr_t cqe_dma_addr;
 	u32 max_entries;
 	u32 id;
+	u32 sq_tail_slot;
+	spinlock_t sq_lock;
 };
 
 static inline bool is_mcq_enabled(struct ufs_hba *hba)