RE: [PATCH v3 3/5] scsi: ufs: add LU Dedicated buffer mode support for WriteBooster

[Avri Altman]

 Hi Stanley,
Few more nits.
Thanks,
Avri

> 
> According to UFS specification, there are two WriteBooster mode of
> operations: "LU dedicated buffer" mode and "shared buffer" mode.
> In the "LU dedicated buffer" mode, the WriteBooster Buffer is
> dedicated to a logical unit.
> 
> If the device supports the "LU dedicated buffer" mode, this mode is
> configured by setting bWriteBoosterBufferType to 00h. The logical
> unit WriteBooster Buffer size is configured by setting the
> dLUNumWriteBoosterBufferAllocUnits field of the related Unit
> Descriptor. Only a value greater than zero enables the WriteBooster
> feature in the logical unit.
> 
> Modify ufshcd_wb_probe() as above description to support LU Dedicated
> buffer mode.
> 
> Note that according to UFS 3.1 specification, the valid value of
> bDeviceMaxWriteBoosterLUs parameter in Geometry Descriptor is 1,
> which means at most one LUN can have WriteBooster buffer in "LU
> dedicated buffer mode". Therefore this patch supports only one
> LUN with WriteBooster enabled. All WriteBooster related sysfs nodes
> are specifically mapped to the LUN with WriteBooster enabled in
> LU Dedicated buffer mode.
> 
> Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> ---
>  drivers/scsi/ufs/ufs-sysfs.c | 14 ++++++++-
>  drivers/scsi/ufs/ufs.h       |  7 +++++
>  drivers/scsi/ufs/ufshcd.c    | 60 +++++++++++++++++++++++++++++-------
>  drivers/scsi/ufs/ufshcd.h    |  1 +
>  4 files changed, 70 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
> index b86b6a40d7e6..a162f63098e5 100644
> --- a/drivers/scsi/ufs/ufs-sysfs.c
> +++ b/drivers/scsi/ufs/ufs-sysfs.c
> @@ -622,16 +622,28 @@ static const struct attribute_group
> ufs_sysfs_string_descriptors_group = {
>         .attrs = ufs_sysfs_string_descriptors,
>  };
> 
> +static bool ufshcd_is_wb_flags(enum flag_idn idn)
Inline?
And just return (idn >= QUERY_FLAG_IDN_WB_EN &&  idn <= QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8)

> +{
> +       if (idn >= QUERY_FLAG_IDN_WB_EN &&
> +           idn <= QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8)
> +               return true;
> +       else
> +               return false;
> +}
> +


> 
> +int ufshcd_wb_get_flag_index(struct ufs_hba *hba)
> +{
> +       if (hba->dev_info.b_wb_buffer_type ==
> WB_BUF_MODE_LU_DEDICATED)
> +               return hba->dev_info.wb_dedicated_lu;
> +       else
No need for else.
Maybe make this static inline in ufshcd.h?

> +               return 0;
> +}
> +