[PATCH v4 21/29] ufs: core: Make the reserved slot a reserved request

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

Instead of letting the SCSI core allocate hba->nutrs - 1 commands, let
the SCSI core allocate hba->nutrs commands, set the number of reserved
tags to 1 and use the reserved tag for device management commands. This
patch changes the 'reserved slot' from hba->nutrs - 1 into 0 because
the block layer reserves the smallest tags for reserved commands.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/ufs/core/ufshcd.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c43fd0a224f4..ce766295d4ca 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2472,7 +2472,7 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba)
 	hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS_SDB) + 1;
 	hba->nutmrs =
 	((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
-	hba->reserved_slot = hba->nutrs - 1;
+	hba->reserved_slot = 0;
 
 	hba->nortt = FIELD_GET(MASK_NUMBER_OUTSTANDING_RTT, hba->capabilities) + 1;
 
@@ -8911,7 +8911,8 @@ static int ufshcd_alloc_mcq(struct ufs_hba *hba)
 		goto err;
 
 	hba->host->can_queue = hba->nutrs - UFSHCD_NUM_RESERVED;
-	hba->reserved_slot = hba->nutrs - UFSHCD_NUM_RESERVED;
+	hba->host->nr_reserved_cmds = UFSHCD_NUM_RESERVED;
+	hba->reserved_slot = 0;
 
 	return 0;
 err:
@@ -10736,6 +10737,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	 * host->cmd_per_lun to a larger value.
 	 */
 	host->cmd_per_lun = 1;
+	host->nr_reserved_cmds = UFSHCD_NUM_RESERVED;
 	host->max_id = UFSHCD_MAX_ID;
 	host->max_lun = UFS_MAX_LUNS;
 	host->max_channel = UFSHCD_MAX_CHANNEL;