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  • Subhash Jadavani's avatar
    ufs: introduce well known logical unit in ufs · 0ce147d4
    Subhash Jadavani authored
    
    
    UFS device may have standard LUs and LUN id could be from 0x00 to 0x7F.
    UFS device specification use "Peripheral Device Addressing Format"
    (SCSI SAM-5) for standard LUs.
    
    UFS device may also have the Well Known LUs (also referred as W-LU) which
    again could be from 0x00 to 0x7F. For W-LUs, UFS device specification only
    allows the "Extended Addressing Format" (SCSI SAM-5) which means the W-LUNs
    would start from 0xC100 onwards.
    
    This means max. LUN number reported from UFS device could be 0xC17F hence
    this patch advertise the "max_lun" as 0xC17F which will allow SCSI mid
    layer to detect the W-LUs as well.
    
    But once the W-LUs are detected, UFSHCD driver may get the commands with
    SCSI LUN id upto 0xC17F but UPIU LUN id field is only 8-bit wide so it
    requires the mapping of SCSI LUN id to UPIU LUN id. This patch also add
    support for this mapping.
    
    Signed-off-by: default avatarSubhash Jadavani <subhashj@codeaurora.org>
    Signed-off-by: default avatarDolev Raviv <draviv@codeaurora.org>
    Signed-off-by: default avatarSujit Reddy Thumma <sthumma@codeaurora.org>
    Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
    0ce147d4