Re: [PATCH v5 10/16] ufs: core: mcq: Use shared tags for MCQ mode

[Manivannan Sadhasivam]

On Tue, Nov 22, 2022 at 08:10:23PM -0800, Asutosh Das wrote:
> Enable shared tags for MCQ. For UFS, this should
> not have a huge performance impact. It however
> simplifies the MCQ implementation and reuses most of
> the existing code in the issue and completion path.
> Also add multiple queue mapping to map_queue().
> 
> Co-developed-by: Can Guo <quic_cang@xxxxxxxxxxx>
> Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
> Signed-off-by: Asutosh Das <quic_asutoshd@xxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>

Thanks,
Mani

> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
>  drivers/ufs/core/ufs-mcq.c |  2 ++
>  drivers/ufs/core/ufshcd.c  | 28 ++++++++++++++++------------
>  2 files changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> index ebecc47..e4ddb90 100644
> --- a/drivers/ufs/core/ufs-mcq.c
> +++ b/drivers/ufs/core/ufs-mcq.c
> @@ -376,6 +376,7 @@ void ufshcd_mcq_make_queues_operational(struct ufs_hba *hba)
>  
>  int ufshcd_mcq_init(struct ufs_hba *hba)
>  {
> +	struct Scsi_Host *host = hba->host;
>  	struct ufs_hw_queue *hwq;
>  	int ret, i;
>  
> @@ -411,6 +412,7 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
>  	/* Give dev_cmd_queue the minimal number of entries */
>  	hba->dev_cmd_queue->max_entries = MAX_DEV_CMD_ENTRIES;
>  
> +	host->host_tagset = 1;
>  	return 0;
>  }
>  
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 042ecf04..d61e99f 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -2763,24 +2763,28 @@ static inline bool is_device_wlun(struct scsi_device *sdev)
>   */
>  static void ufshcd_map_queues(struct Scsi_Host *shost)
>  {
> -	int i;
> +	struct ufs_hba *hba = shost_priv(shost);
> +	int i, queue_offset = 0;
> +
> +	if (!is_mcq_supported(hba)) {
> +		hba->nr_queues[HCTX_TYPE_DEFAULT] = 1;
> +		hba->nr_queues[HCTX_TYPE_READ] = 0;
> +		hba->nr_queues[HCTX_TYPE_POLL] = 1;
> +		hba->nr_hw_queues = 1;
> +	}
>  
>  	for (i = 0; i < shost->nr_maps; i++) {
>  		struct blk_mq_queue_map *map = &shost->tag_set.map[i];
>  
> -		switch (i) {
> -		case HCTX_TYPE_DEFAULT:
> -		case HCTX_TYPE_POLL:
> -			map->nr_queues = 1;
> -			break;
> -		case HCTX_TYPE_READ:
> -			map->nr_queues = 0;
> +		map->nr_queues = hba->nr_queues[i];
> +		if (!map->nr_queues)
>  			continue;
> -		default:
> -			WARN_ON_ONCE(true);
> -		}
> -		map->queue_offset = 0;
> +		map->queue_offset = queue_offset;
> +		if (i == HCTX_TYPE_POLL && !is_mcq_supported(hba))
> +			map->queue_offset = 0;
> +
>  		blk_mq_map_queues(map);
> +		queue_offset += map->nr_queues;
>  	}
>  }
>  
> -- 
> 2.7.4
> 

-- 
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