scsi: ufs: core: Simplify ufshcd_err_handling_prepare()

Use blk_mq_quiesce_tagset() instead of ufshcd_scsi_block_requests() and
blk_mq_wait_quiesce_done(). Since this patch removes the last callers of
ufshcd_scsi_block_requests() and ufshcd_scsi_unblock_requests(), remove
these functions.

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241022193130.2733293-6-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufshcd.c

@@ -349,18 +349,6 @@ static void ufshcd_configure_wb(struct ufs_hba *hba)
 		ufshcd_wb_toggle_buf_flush(hba, true);
 }
 
-static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
-{
-	if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt))
-		scsi_unblock_requests(hba->host);
-}
-
-static void ufshcd_scsi_block_requests(struct ufs_hba *hba)
-{
-	if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1)
-		scsi_block_requests(hba->host);
-}
-
 static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag,
 				      enum ufs_trace_str_t str_t)
 {
@@ -6375,15 +6363,14 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
 			ufshcd_suspend_clkscaling(hba);
 		ufshcd_clk_scaling_allow(hba, false);
 	}
-	ufshcd_scsi_block_requests(hba);
 	/* Wait for ongoing ufshcd_queuecommand() calls to finish. */
-	blk_mq_wait_quiesce_done(&hba->host->tag_set);
+	blk_mq_quiesce_tagset(&hba->host->tag_set);
 	cancel_work_sync(&hba->eeh_work);
 }
 
 static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
 {
-	ufshcd_scsi_unblock_requests(hba);
+	blk_mq_unquiesce_tagset(&hba->host->tag_set);
 	ufshcd_release(hba);
 	if (ufshcd_is_clkscaling_supported(hba))
 		ufshcd_clk_scaling_suspend(hba, false);
@@ -10558,7 +10545,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 
 	/* Hold auto suspend until async scan completes */
 	pm_runtime_get_sync(dev);
-	atomic_set(&hba->scsi_block_reqs_cnt, 0);
+
 	/*
 	 * We are assuming that device wasn't put in sleep/power-down
 	 * state exclusively during the boot stage before kernel.

include/ufs/ufshcd.h

@@ -925,7 +925,6 @@ enum ufshcd_mcq_opr {
  * @wb_mutex: used to serialize devfreq and sysfs write booster toggling
  * @clk_scaling_lock: used to serialize device commands and clock scaling
  * @desc_size: descriptor sizes reported by device
- * @scsi_block_reqs_cnt: reference counting for scsi block requests
  * @bsg_dev: struct device associated with the BSG queue
  * @bsg_queue: BSG queue associated with the UFS controller
  * @rpm_dev_flush_recheck_work: used to suspend from RPM (runtime power
@@ -1086,7 +1085,6 @@ struct ufs_hba {
 
 	struct mutex wb_mutex;
 	struct rw_semaphore clk_scaling_lock;
-	atomic_t scsi_block_reqs_cnt;
 
 	struct device		bsg_dev;
 	struct request_queue	*bsg_queue;