Linux SCSI subsystem development
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From: Bart Van Assche <bvanassche@acm.org>
To: "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org, Bart Van Assche <bvanassche@acm.org>,
	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	Peter Wang <peter.wang@mediatek.com>,
	Avri Altman <avri.altman@sandisk.com>,
	Bean Huo <beanhuo@micron.com>
Subject: [PATCH v5 21/28] ufs: core: Make the reserved slot a reserved request
Date: Wed, 24 Sep 2025 13:30:40 -0700	[thread overview]
Message-ID: <20250924203142.4073403-22-bvanassche@acm.org> (raw)
In-Reply-To: <20250924203142.4073403-1-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 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index bb14af688e98..1dbb5bdf84f2 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2475,7 +2475,7 @@ 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;
 
@@ -8915,7 +8915,6 @@ 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;
 
 	return 0;
 err:
@@ -10740,6 +10739,7 @@ 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;

  parent reply	other threads:[~2025-09-24 20:34 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-24 20:30 [PATCH v5 00/28] Optimize the hot path in the UFS driver Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 01/28] scsi: core: Support allocating reserved commands Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 02/28] scsi: core: Move two statements Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 03/28] scsi: core: Make the budget map optional Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 04/28] scsi: core: Support allocating a pseudo SCSI device Bart Van Assche
2025-09-26  7:14   ` John Garry
2025-09-26 20:01     ` Bart Van Assche
2025-09-26 22:21   ` Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 05/28] scsi: core: Introduce .queue_reserved_command() Bart Van Assche
2025-09-26  7:24   ` John Garry
2025-09-26 20:05     ` Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 06/28] scsi: core: Add scsi_{get,put}_internal_cmd() helpers Bart Van Assche
2025-09-25 16:38   ` John Garry
2025-09-24 20:30 ` [PATCH v5 07/28] scsi_debug: Abort SCSI commands via .queue_reserved_command() Bart Van Assche
2025-09-26  7:32   ` John Garry
2025-09-26 20:44     ` Bart Van Assche
2025-09-30  7:03       ` John Garry
2025-10-01 18:26         ` Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 08/28] ufs: core: Move an assignment in ufshcd_mcq_process_cqe() Bart Van Assche
2025-09-26  6:12   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 09/28] ufs: core: Change the type of one ufshcd_add_cmd_upiu_trace() argument Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 10/28] ufs: core: Only call ufshcd_add_command_trace() for SCSI commands Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 11/28] ufs: core: Change the type of one ufshcd_add_command_trace() argument Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 12/28] ufs: core: Change the type of one ufshcd_send_command() argument Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 13/28] ufs: core: Only call ufshcd_should_inform_monitor() for SCSI commands Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 14/28] ufs: core: Change the monitor function argument types Bart Van Assche
2025-09-26  6:24   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 15/28] ufs: core: Rework ufshcd_mcq_compl_pending_transfer() Bart Van Assche
2025-09-26  6:44   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 16/28] ufs: core: Rework ufshcd_eh_device_reset_handler() Bart Van Assche
2025-09-26  7:17   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 17/28] ufs: core: Rework the SCSI host queue depth calculation code Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 18/28] ufs: core: Allocate the SCSI host earlier Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 19/28] ufs: core: Call ufshcd_init_lrb() later Bart Van Assche
2025-09-27  9:39   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 20/28] ufs: core: Use hba->reserved_slot Bart Van Assche
2025-09-24 20:30 ` Bart Van Assche [this message]
2025-09-24 20:30 ` [PATCH v5 22/28] ufs: core: Do not clear driver-private command data Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 23/28] ufs: core: Optimize the hot path Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 24/28] ufs: core: Pass a SCSI pointer instead of an LRB pointer Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 25/28] ufs: core: Remove the ufshcd_lrb task_tag member Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 26/28] ufs: core: Make blk_mq_tagset_busy_iter() skip reserved requests Bart Van Assche
2025-09-24 20:30 ` [PATCH v5 27/28] ufs: core: Move code out of ufshcd_wait_for_dev_cmd() Bart Van Assche
2025-09-27  9:11   ` Avri Altman
2025-09-24 20:30 ` [PATCH v5 28/28] ufs: core: Switch to scsi_get_internal_cmd() Bart Van Assche
2025-09-26 10:08 ` [PATCH v5 00/28] Optimize the hot path in the UFS driver John Garry
2025-09-26 17:32   ` Bart Van Assche

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