• Mike Miller's avatar
    cciss: add performant mode support for Stars/Sirius · 5e216153
    Mike Miller authored
    Add a mode of controller operation called Performant Mode.  Even though
    cciss has been deprecated in favor of hpsa there are new controllers due
    out next year that HP must support in older vendor distros.  Vendors
    require all fixes/features be upstream.  These new controllers support
    only 16 commands in simple mode but support up to 1024 in performant mode.
    This requires us to add this support at this late date.
    
    The performant mode transport minimizes host PCI accesses by performinf
    many completions per read.  PCI writes are posted so the host can write
    then immediately get off the bus not waiting for the writwe to complete to
    the target.  In the context of performant mode the host read out to a
    controller pulls all posted writes into host memory ensuring the reply
    queue is coherent.
    Signed-off-by: default avatarMike Miller <mike.miller@hp.com>
    Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
    5e216153
cciss_scsi.c 49.7 KB