[PATCH 7/8] scsi: ufs: Make the polling code report which command has been completed

[Bart Van Assche <bvanassche@acm.org>]

Prepare for introducing a new __ufshcd_poll() caller that will need to
know whether or not a specific command has been completed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/ufs/core/ufs-mcq.c      | 25 +++++++++++++-------
 drivers/ufs/core/ufshcd-priv.h  |  4 ++--
 drivers/ufs/core/ufshcd.c       | 41 +++++++++++++++++++++++----------
 drivers/ufs/host/ufs-mediatek.c |  2 +-
 drivers/ufs/host/ufs-qcom.c     |  2 +-
 include/ufs/ufshcd.h            |  3 ++-
 6 files changed, 52 insertions(+), 25 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index d6f966f4abef..c9155759934c 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -294,17 +294,22 @@ static int ufshcd_mcq_get_tag(struct ufs_hba *hba, struct cq_entry *cqe)
 	return div_u64(addr, ufshcd_get_ucd_size(hba));
 }
 
-static void ufshcd_mcq_process_cqe(struct ufs_hba *hba,
-				   struct ufs_hw_queue *hwq)
+/* Returns true if and only if @compl_cmd has been completed. */
+static bool ufshcd_mcq_process_cqe(struct ufs_hba *hba,
+				   struct ufs_hw_queue *hwq,
+				   struct scsi_cmnd *compl_cmd)
 {
 	struct cq_entry *cqe = ufshcd_mcq_cur_cqe(hwq);
-	int tag = ufshcd_mcq_get_tag(hba, cqe);
 
 	if (cqe->command_desc_base_addr) {
-		ufshcd_compl_one_cqe(hba, tag, cqe);
-		/* After processed the cqe, mark it empty (invalid) entry */
+		const int tag = ufshcd_mcq_get_tag(hba, cqe);
+
+		/* Mark the CQE as invalid. */
 		cqe->command_desc_base_addr = 0;
+
+		return ufshcd_compl_one_cqe(hba, tag, cqe, compl_cmd);
 	}
+	return false;
 }
 
 void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
@@ -315,7 +320,7 @@ void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
 
 	spin_lock_irqsave(&hwq->cq_lock, flags);
 	while (entries > 0) {
-		ufshcd_mcq_process_cqe(hba, hwq);
+		ufshcd_mcq_process_cqe(hba, hwq, NULL);
 		ufshcd_mcq_inc_cq_head_slot(hwq);
 		entries--;
 	}
@@ -325,8 +330,10 @@ void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
 	spin_unlock_irqrestore(&hwq->cq_lock, flags);
 }
 
+/* Clears *@compl_cmd if and only if *@compl_cmd has been completed. */
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
-				       struct ufs_hw_queue *hwq)
+				       struct ufs_hw_queue *hwq,
+				       struct scsi_cmnd **compl_cmd)
 {
 	unsigned long completed_reqs = 0;
 	unsigned long flags;
@@ -334,7 +341,9 @@ unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
 	spin_lock_irqsave(&hwq->cq_lock, flags);
 	ufshcd_mcq_update_cq_tail_slot(hwq);
 	while (!ufshcd_mcq_is_cq_empty(hwq)) {
-		ufshcd_mcq_process_cqe(hba, hwq);
+		if (ufshcd_mcq_process_cqe(hba, hwq,
+					   compl_cmd ? *compl_cmd : NULL))
+			*compl_cmd = NULL;
 		ufshcd_mcq_inc_cq_head_slot(hwq);
 		completed_reqs++;
 	}
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index fb4457a84d11..42802fd689fb 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -61,8 +61,8 @@ int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
 int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
 	enum flag_idn idn, u8 index, bool *flag_res);
 void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit);
-void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
-			  struct cq_entry *cqe);
+bool ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
+			  struct cq_entry *cqe, struct scsi_cmnd *compl_cmd);
 int ufshcd_mcq_init(struct ufs_hba *hba);
 int ufshcd_mcq_decide_queue_depth(struct ufs_hba *hba);
 int ufshcd_mcq_memory_alloc(struct ufs_hba *hba);
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index db374a788140..e3835e61e4b1 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5488,9 +5488,12 @@ void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
  * @hba: per adapter instance
  * @task_tag: the task tag of the request to be completed
  * @cqe: pointer to the completion queue entry
+ * @compl_cmd: if not NULL, check whether this command has been completed
+ *
+ * Returns: true if and only if @compl_cmd has been completed.
  */
-void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
-			  struct cq_entry *cqe)
+bool ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
+			  struct cq_entry *cqe, struct scsi_cmnd *compl_cmd)
 {
 	struct ufshcd_lrb *lrbp;
 	struct scsi_cmnd *cmd;
@@ -5507,6 +5510,7 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
 		ufshcd_release_scsi_cmd(hba, lrbp);
 		/* Do not touch lrbp after scsi done */
 		scsi_done(cmd);
+		return cmd == compl_cmd;
 	} else if (hba->dev_cmd.complete) {
 		if (cqe) {
 			ocs = le32_to_cpu(cqe->status) & MASK_OCS;
@@ -5514,20 +5518,26 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
 		}
 		complete(hba->dev_cmd.complete);
 	}
+	return false;
 }
 
 /**
  * __ufshcd_transfer_req_compl - handle SCSI and query command completion
  * @hba: per adapter instance
  * @completed_reqs: bitmask that indicates which requests to complete
+ * @compl_cmd: if not NULL, check whether *@compl_cmd has been completed.
+ *	Clear *@compl_cmd if it has been completed.
  */
 static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
-					unsigned long completed_reqs)
+					unsigned long completed_reqs,
+					struct scsi_cmnd **compl_cmd)
 {
 	int tag;
 
 	for_each_set_bit(tag, &completed_reqs, hba->nutrs)
-		ufshcd_compl_one_cqe(hba, tag, NULL);
+		if (ufshcd_compl_one_cqe(hba, tag, NULL,
+					 compl_cmd ? *compl_cmd : NULL))
+			*compl_cmd = NULL;
 }
 
 /* Any value that is not an existing queue number is fine for this constant. */
@@ -5554,7 +5564,8 @@ static void ufshcd_clear_polled(struct ufs_hba *hba,
  * Return: > 0 if one or more commands have been completed or 0 if no
  * requests have been completed.
  */
-static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
+static int __ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num,
+			 struct scsi_cmnd **compl_cmd)
 {
 	struct ufs_hba *hba = shost_priv(shost);
 	unsigned long completed_reqs, flags;
@@ -5565,7 +5576,7 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
 		WARN_ON_ONCE(queue_num == UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
 		hwq = &hba->uhq[queue_num];
 
-		return ufshcd_mcq_poll_cqe_lock(hba, hwq);
+		return ufshcd_mcq_poll_cqe_lock(hba, hwq, compl_cmd);
 	}
 
 	spin_lock_irqsave(&hba->outstanding_lock, flags);
@@ -5582,11 +5593,16 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
 	spin_unlock_irqrestore(&hba->outstanding_lock, flags);
 
 	if (completed_reqs)
-		__ufshcd_transfer_req_compl(hba, completed_reqs);
+		__ufshcd_transfer_req_compl(hba, completed_reqs, compl_cmd);
 
 	return completed_reqs != 0;
 }
 
+static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
+{
+	return __ufshcd_poll(shost, queue_num, NULL);
+}
+
 /**
  * ufshcd_mcq_compl_pending_transfer - MCQ mode function. It is
  * invoked from the error handler context or ufshcd_host_reset_and_restore()
@@ -5630,7 +5646,7 @@ static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
 			}
 			spin_unlock_irqrestore(&hwq->cq_lock, flags);
 		} else {
-			ufshcd_mcq_poll_cqe_lock(hba, hwq);
+			ufshcd_mcq_poll_cqe_lock(hba, hwq, NULL);
 		}
 	}
 }
@@ -6905,7 +6921,7 @@ static irqreturn_t ufshcd_handle_mcq_cq_events(struct ufs_hba *hba)
 			ufshcd_mcq_write_cqis(hba, events, i);
 
 		if (events & UFSHCD_MCQ_CQIS_TAIL_ENT_PUSH_STS)
-			ufshcd_mcq_poll_cqe_lock(hba, hwq);
+			ufshcd_mcq_poll_cqe_lock(hba, hwq, NULL);
 	}
 
 	return IRQ_HANDLED;
@@ -7398,7 +7414,7 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
 			    lrbp->lun == lun) {
 				ufshcd_clear_cmd(hba, pos);
 				hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(lrbp->cmd));
-				ufshcd_mcq_poll_cqe_lock(hba, hwq);
+				ufshcd_mcq_poll_cqe_lock(hba, hwq, NULL);
 			}
 		}
 		err = 0;
@@ -7426,7 +7442,8 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
 				__func__, pos);
 		}
 	}
-	__ufshcd_transfer_req_compl(hba, pending_reqs & ~not_cleared_mask);
+	__ufshcd_transfer_req_compl(hba, pending_reqs & ~not_cleared_mask,
+				    NULL);
 
 out:
 	hba->req_abort_count = 0;
@@ -7603,7 +7620,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 		dev_err(hba->dev,
 		"%s: cmd was completed, but without a notifying intr, tag = %d",
 		__func__, tag);
-		__ufshcd_transfer_req_compl(hba, 1UL << tag);
+		__ufshcd_transfer_req_compl(hba, 1UL << tag, NULL);
 		goto release;
 	}
 
diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index c7a0ab9b1f59..4dbe334b36bb 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -1715,7 +1715,7 @@ static irqreturn_t ufs_mtk_mcq_intr(int irq, void *__intr_info)
 		ufshcd_mcq_write_cqis(hba, events, qid);
 
 	if (events & UFSHCD_MCQ_CQIS_TAIL_ENT_PUSH_STS)
-		ufshcd_mcq_poll_cqe_lock(hba, hwq);
+		ufshcd_mcq_poll_cqe_lock(hba, hwq, NULL);
 
 	return IRQ_HANDLED;
 }
diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index cca190d1c577..cc1d9614fcd6 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -1715,7 +1715,7 @@ static irqreturn_t ufs_qcom_mcq_esi_handler(int irq, void *data)
 	struct ufs_hw_queue *hwq = &hba->uhq[id];
 
 	ufshcd_mcq_write_cqis(hba, 0x1, id);
-	ufshcd_mcq_poll_cqe_lock(hba, hwq);
+	ufshcd_mcq_poll_cqe_lock(hba, hwq, NULL);
 
 	return IRQ_HANDLED;
 }
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index d32637d267f3..443afb97a637 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1284,7 +1284,8 @@ unsigned int ufshcd_mcq_queue_cfg_addr(struct ufs_hba *hba);
 u32 ufshcd_mcq_read_cqis(struct ufs_hba *hba, int i);
 void ufshcd_mcq_write_cqis(struct ufs_hba *hba, u32 val, int i);
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
-					 struct ufs_hw_queue *hwq);
+				       struct ufs_hw_queue *hwq,
+				       struct scsi_cmnd **compl_cmd);
 void ufshcd_mcq_make_queues_operational(struct ufs_hba *hba);
 void ufshcd_mcq_enable_esi(struct ufs_hba *hba);
 void ufshcd_mcq_enable(struct ufs_hba *hba);