[v3,7/7] scsi: ufs: Make .get_hba_mac() optional

UFSHCI controllers that are compliant with the UFSHCI 4.0 standard report
the maximum number of supported commands in the controller capabilities
register. Use that value if .get_hba_mac == NULL.

Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/ufs/core/ufs-mcq.c | 15 +++++++++------
 include/ufs/ufshcd.h       |  4 +++-
 include/ufs/ufshci.h       |  1 +
 3 files changed, 13 insertions(+), 7 deletions(-)

On Mon, 2024-07-01 at 11:03 -0700, Bart Van Assche wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  UFSHCI controllers that are compliant with the UFSHCI 4.0 standard
> report
> the maximum number of supported commands in the controller
> capabilities
> register. Use that value if .get_hba_mac == NULL.
> 
> Reviewed-by: Daejun Park <daejun7.park@samsung.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  drivers/ufs/core/ufs-mcq.c | 15 +++++++++------
>  include/ufs/ufshcd.h       |  4 +++-
>  include/ufs/ufshci.h       |  1 +
>  3 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> index 0482c7a1e419..f4cc4b0676f7 100644
> --- a/drivers/ufs/core/ufs-mcq.c
> +++ b/drivers/ufs/core/ufs-mcq.c
> @@ -138,18 +138,21 @@ EXPORT_SYMBOL_GPL(ufshcd_mcq_queue_cfg_addr);
>   *
>   * MAC - Max. Active Command of the Host Controller (HC)
>   * HC wouldn't send more than this commands to the device.
> - * It is mandatory to implement get_hba_mac() to enable MCQ mode.
>   * Calculates and adjusts the queue depth based on the depth
>   * supported by the HC and ufs device.
>   */
>  int ufshcd_mcq_decide_queue_depth(struct ufs_hba *hba)
>  {
> -	int mac = -EOPNOTSUPP;
> +	int mac;
>  
> -	if (!hba->vops || !hba->vops->get_hba_mac)
> -		goto err;
> -
> -	mac = hba->vops->get_hba_mac(hba);
> +	if (!hba->vops || !hba->vops->get_hba_mac) {
> +		hba->capabilities =
> +			ufshcd_readl(hba, REG_CONTROLLER_CAPABILITIES);
> +		mac = hba->capabilities &
> MASK_TRANSFER_REQUESTS_SLOTS_MCQ;
> 

Hi Bart,

Before ufshcd_mcq_enable,
here read REG_CONTROLLER_CAPABILITIES should be SDB value.
Beacuse MCQ is not enable.


Thanks.
Peter



> +		mac++;
> +	} else {
> +		mac = hba->vops->get_hba_mac(hba);
> +	}
>  	if (mac < 0)
>  		goto err;
>  
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index d4d63507d090..d32637d267f3 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -325,7 +325,9 @@ struct ufs_pwr_mode_info {
>   * @event_notify: called to notify important events
>   * @reinit_notify: called to notify reinit of UFSHCD during max gear
> switch
>   * @mcq_config_resource: called to configure MCQ platform resources
> - * @get_hba_mac: called to get vendor specific mac value, mandatory
> for mcq mode
> + * @get_hba_mac: reports maximum number of outstanding commands
> supported by
> + *	the controller. Should be implemented for UFSHCI 4.0 or later
> + *	controllers that are not compliant with the UFSHCI 4.0
> specification.
>   * @op_runtime_config: called to config Operation and runtime regs
> Pointers
>   * @get_outstanding_cqs: called to get outstanding completion queues
>   * @config_esi: called to config Event Specific Interrupt
> diff --git a/include/ufs/ufshci.h b/include/ufs/ufshci.h
> index 8d0cc73537c6..38fe97971a65 100644
> --- a/include/ufs/ufshci.h
> +++ b/include/ufs/ufshci.h
> @@ -68,6 +68,7 @@ enum {
>  /* Controller capability masks */
>  enum {
>  	MASK_TRANSFER_REQUESTS_SLOTS_SDB	= 0x0000001F,
> +	MASK_TRANSFER_REQUESTS_SLOTS_MCQ	= 0x000000FF,
>  	MASK_NUMBER_OUTSTANDING_RTT		= 0x0000FF00,
>  	MASK_TASK_MANAGEMENT_REQUEST_SLOTS	= 0x00070000,
>  	MASK_EHSLUTRD_SUPPORTED			= 0x00400000,

On 7/1/24 11:29 PM, Peter Wang (王信友) wrote:
> Before ufshcd_mcq_enable,
> here read REG_CONTROLLER_CAPABILITIES should be SDB value.
> Beacuse MCQ is not enable.

I think this needs to be fixed in another way, namely by enabling MCQ
before ufshcd_mcq_decide_queue_depth() is called. See also v3 of this
patch series.

Thanks,

Bart.

On Tue, 2024-07-02 at 13:27 -0700, Bart Van Assche wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  
> On 7/1/24 11:29 PM, Peter Wang (王信友) wrote:
> > Before ufshcd_mcq_enable,
> > here read REG_CONTROLLER_CAPABILITIES should be SDB value.
> > Beacuse MCQ is not enable.
> 
> I think this needs to be fixed in another way, namely by enabling MCQ
> before ufshcd_mcq_decide_queue_depth() is called. See also v3 of this
> patch series.
> 
> Thanks,
> 
> Bart.
> 

Hi Bart,

Yes, enable mcq before ufshcd_mcq_decide_queue_depth is right.

Thanks.
Peter