• Matthew R. Ochs's avatar
    scsi: cxlflash: Support WS16 unmap · 3223c01a
    Matthew R. Ochs authored
    The cxlflash driver supports performing a write-same16 to scrub virtual
    luns when they are released by a user. To date, AFUs for adapters that
    are supported by cxlflash do not have the capability to unmap as part of
    the WS operation. This can lead to fragmented flash devices which results
    in performance degradation.
    
    Future AFUs can optionally support unmap write-same commands and reflects
    this support via the context control register. This provides userspace
    applications with direct visibility such that they need not depend on a
    host API.
    
    Detect unmap support during cxlflash initialization by reading the context
    control register associated with the primary hardware queue. Update the
    existing write_same16() routine to set the unmap bit in the CDB when unmap
    is supported by the host.
    Signed-off-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
    Signed-off-by: default avatarUma Krishnan <ukrishn@linux.vnet.ibm.com>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    3223c01a
sislite.h 18.7 KB