scsi: ufs: core: Switch to scsi_get_internal_cmd()

Instead of storing the tag of the reserved command in hba->reserved_slot,
use scsi_get_internal_cmd() and scsi_put_internal_cmd() to allocate the
tag for the reserved command dynamically. Add
ufshcd_queue_reserved_command() for submitting reserved commands. Add
support in ufshcd_abort() for device management commands. Use
blk_execute_rq() for submitting reserved commands. Remove the code and
data structures that became superfluous. This includes
ufshcd_wait_for_dev_cmd(), hba->reserved_slot and ufs_dev_cmd.complete.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251031204029.2883185-29-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: bvanassche

drivers/ufs/core/ufs-mcq.c

@@ -479,9 +479,6 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
 		mutex_init(&hwq->sq_mutex);
 	}
 
-	/* The very first HW queue serves device commands */
-	hba->dev_cmd_queue = &hba->uhq[0];
-
 	host->host_tagset = 1;
 	return 0;
 }
@@ -536,6 +533,7 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
 {
 	struct scsi_cmnd *cmd = ufshcd_tag_to_cmd(hba, task_tag);
 	struct ufshcd_lrb *lrbp = scsi_cmd_priv(cmd);
+	struct request *rq = scsi_cmd_to_rq(cmd);
 	struct ufs_hw_queue *hwq;
 	void __iomem *reg, *opr_sqd_base;
 	u32 nexus, id, val;
@@ -544,15 +542,12 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
 	if (hba->quirks & UFSHCD_QUIRK_MCQ_BROKEN_RTC)
 		return -ETIMEDOUT;
 
-	if (task_tag != hba->reserved_slot) {
-		if (!cmd)
-			return -EINVAL;
-		hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
-		if (!hwq)
-			return 0;
-	} else {
-		hwq = hba->dev_cmd_queue;
-	}
+	if (!cmd)
+		return -EINVAL;
+
+	hwq = ufshcd_mcq_req_to_hwq(hba, rq);
+	if (!hwq)
+		return 0;
 
 	id = hwq->id;
 

drivers/ufs/core/ufshcd-priv.h

@@ -369,30 +369,7 @@ static inline bool ufs_is_valid_unit_desc_lun(struct ufs_dev_info *dev_info, u8
 static inline struct scsi_cmnd *ufshcd_tag_to_cmd(struct ufs_hba *hba, u32 tag)
 {
 	struct blk_mq_tags *tags = hba->host->tag_set.shared_tags;
-	struct request *rq;
-
-	/*
-	 * Handle reserved tags differently because the UFS driver does not
-	 * call blk_mq_alloc_request() for allocating reserved requests.
-	 * Allocating reserved tags with blk_mq_alloc_request() would require
-	 * the following:
-	 * - Allocate an additional request queue from &hba->host->tag_set for
-	 *   allocating reserved requests from.
-	 * - For that request queue, allocate a SCSI device.
-	 * - Calling blk_mq_alloc_request(hba->dev_mgmt_queue, REQ_OP_DRV_OUT,
-	 *   BLK_MQ_REQ_RESERVED) for allocating a reserved request and
-	 *   blk_mq_free_request() for freeing reserved requests.
-	 * - Set the .device pointer for these reserved requests.
-	 * - Submit reserved requests with blk_execute_rq().
-	 * - Modify ufshcd_queuecommand() such that it handles reserved requests
-	 *   in another way than SCSI requests.
-	 * - Modify ufshcd_compl_one_cqe() such that it calls scsi_done() for
-	 *   device management commands.
-	 * - Modify all callback functions called by blk_mq_tagset_busy_iter()
-	 *   calls in the UFS driver and skip device management commands.
-	 */
-	rq = tag < UFSHCD_NUM_RESERVED ? tags->static_rqs[tag] :
-					 blk_mq_tag_to_rq(tags, tag);
+	struct request *rq = blk_mq_tag_to_rq(tags, tag);
 
 	if (WARN_ON_ONCE(!rq))
 		return NULL;