[PATCH 3/3] ufs: core: Do not forcibly complete SCSI commands

The SCSI core error handler is responsible for deciding whether to abort or
to requeue SCSI commands. A SCSI LLD shouldn't interfere with this decision.
Hence, do not forcibly complete SCSI commands from inside the UFS error
handler. This patch makes the MCQ behavior consistent with the behavior for
legacy mode.

Fixes: ab248643d3d6 ("scsi: ufs: core: Add error handling for MCQ mode")
Signed-off-by: Bart Van Assche <[email protected]>
---
 drivers/ufs/core/ufs-mcq.c     | 26 ------------------
 drivers/ufs/core/ufshcd-priv.h |  2 --
 drivers/ufs/core/ufshcd.c      | 48 +++++-----------------------------
 3 files changed, 7 insertions(+), 69 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 8106d55f4041..55ed72d15ada 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -328,32 +328,6 @@ static void ufshcd_mcq_process_cqe(struct ufs_hba *hba,
 	}
 }
 
-/*
- * This function is called from the UFS error handler with the UFS host
- * controller disabled (HCE = 0). Reading host controller registers, e.g. the
- * CQ tail pointer (CQTPy), may not be safe with the host controller disabled.
- * Hence, iterate over all completion queue entries. This won't result in
- * double completions because ufshcd_mcq_process_cqe() clears a CQE after it
- * has been processed.
- */
-void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
-				    struct ufs_hw_queue *hwq)
-{
-	unsigned long flags;
-	u32 entries = hwq->max_entries;
-
-	spin_lock_irqsave(&hwq->cq_lock, flags);
-	while (entries > 0) {
-		ufshcd_mcq_process_cqe(hba, hwq);
-		ufshcd_mcq_inc_cq_head_slot(hwq);
-		entries--;
-	}
-
-	ufshcd_mcq_update_cq_tail_slot(hwq);
-	hwq->cq_head_slot = hwq->cq_tail_slot;
-	spin_unlock_irqrestore(&hwq->cq_lock, flags);
-}
-
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
 				       struct ufs_hw_queue *hwq)
 {
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index e55c2a02c1f5..8ddc19143abf 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -73,8 +73,6 @@ int ufshcd_get_hba_mac(struct ufs_hba *hba);
 int ufshcd_mcq_memory_alloc(struct ufs_hba *hba);
 struct ufs_hw_queue *ufshcd_mcq_req_to_hwq(struct ufs_hba *hba,
 					   struct request *req);
-void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
-				    struct ufs_hw_queue *hwq);
 bool ufshcd_cmd_inflight(struct scsi_cmnd *cmd);
 int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag);
 int ufshcd_mcq_abort(struct scsi_cmnd *cmd);
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 0618712be32c..963784f8c0a6 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6018,34 +6018,6 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
 	return completed_reqs != 0;
 }
 
-static bool ufshcd_mcq_force_compl_one(struct request *rq, void *priv)
-{
-	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
-	struct scsi_device *sdev = rq->q->queuedata;
-	struct Scsi_Host *shost = sdev->host;
-	struct ufs_hba *hba = shost_priv(shost);
-	struct ufs_hw_queue *hwq = ufshcd_mcq_req_to_hwq(hba, rq);
-
-	if (blk_mq_is_reserved_rq(rq) || !hwq)
-		return true;
-
-	ufshcd_mcq_compl_all_cqes_lock(hba, hwq);
-
-	/*
-	 * For those cmds of which the cqes are not present in the cq, complete
-	 * them explicitly.
-	 */
-	scoped_guard(spinlock_irqsave, &hwq->cq_lock) {
-		if (!test_bit(SCMD_STATE_COMPLETE, &cmd->state)) {
-			set_host_byte(cmd, DID_REQUEUE);
-			ufshcd_release_scsi_cmd(hba, cmd);
-			scsi_done(cmd);
-		}
-	}
-
-	return true;
-}
-
 static bool ufshcd_mcq_compl_one(struct request *rq, void *priv)
 {
 	struct scsi_device *sdev = rq->q->queuedata;
@@ -6066,16 +6038,10 @@ static bool ufshcd_mcq_compl_one(struct request *rq, void *priv)
  * the scsi command.
  *
  * @hba: per adapter instance
- * @force_compl: This flag is set to true when invoked
- * from ufshcd_host_reset_and_restore() in which case it requires special
- * handling because the host controller has been reset by ufshcd_hba_stop().
  */
-static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
-					      bool force_compl)
+static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba)
 {
-	blk_mq_tagset_busy_iter(&hba->host->tag_set,
-				force_compl ? ufshcd_mcq_force_compl_one :
-					      ufshcd_mcq_compl_one,
+	blk_mq_tagset_busy_iter(&hba->host->tag_set, ufshcd_mcq_compl_one,
 				NULL);
 }
 
@@ -6632,10 +6598,10 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 }
 
 /* Complete requests that have door-bell cleared */
-static void ufshcd_complete_requests(struct ufs_hba *hba, bool force_compl)
+static void ufshcd_complete_requests(struct ufs_hba *hba)
 {
 	if (hba->mcq_enabled)
-		ufshcd_mcq_compl_pending_transfer(hba, force_compl);
+		ufshcd_mcq_compl_pending_transfer(hba);
 	else
 		ufshcd_transfer_req_compl(hba);
 
@@ -6936,7 +6902,7 @@ static bool ufshcd_abort_all(struct ufs_hba *hba)
 
 out:
 	/* Complete the requests that are cleared by s/w */
-	ufshcd_complete_requests(hba, false);
+	ufshcd_complete_requests(hba);
 
 	return ret != 0;
 }
@@ -6998,7 +6964,7 @@ static void ufshcd_err_handler(struct work_struct *work)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	/* Complete requests that have door-bell cleared by h/w */
-	ufshcd_complete_requests(hba, false);
+	ufshcd_complete_requests(hba);
 	spin_lock_irqsave(hba->host->host_lock, flags);
 again:
 	needs_restore = false;
@@ -8229,7 +8195,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	 */
 	ufshcd_hba_stop(hba);
 	hba->silence_err_logs = true;
-	ufshcd_complete_requests(hba, true);
+	ufshcd_complete_requests(hba);
 	hba->silence_err_logs = false;
 
 	/* scale up clocks to max frequency before full reinitialization */