• Luis R. Rodriguez's avatar
    x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled · 7ea402d0
    Luis R. Rodriguez authored
    We are burrying direct access to MTRR code support on
    x86 in order to take advantage of PAT. In the future, we
    also want to make the default behaviour of ioremap_nocache()
    to use strong UC, use of mtrr_add() on those systems
    would make write-combining void.
    
    In order to help both enable us to later make strong
    UC default and in order to phase out direct MTRR access
    code port the driver over to arch_phys_wc_add() and
    annotate that the device driver requires systems to
    boot with PAT disabled, with the 'nopat' kernel parameter.
    
    This is a workable compromise given that the ipath device
    driver powers the old HTX bus cards that only work in
    AMD systems, while the newer IB/qib device driver
    powers all PCI-e cards. The ipath device driver is
    obsolete, hardware is hard to find and because of this
    its a reasonable compromise to require users of ipath
    to boot with 'nopat'.
    Signed-off-by: default avatarLuis R. Rodriguez <mcgrof@suse.com>
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Acked-by: default avatarDoug Ledford <dledford@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Andy Walls <awalls@md.metrocast.net>
    Cc: Antonino Daplas <adaplas@gmail.com>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: Bjorn Helgaas <bhelgaas@google.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brian Gerst <brgerst@gmail.com>
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Cc: Dave Airlie <airlied@redhat.com>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
    Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Michael S. Tsirkin <mst@redhat.com>
    Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
    Cc: Roger Pau Monné <roger.pau@citrix.com>
    Cc: Roland Dreier <roland@purestorage.com>
    Cc: Sean Hefty <sean.hefty@intel.com>
    Cc: Stefan Bader <stefan.bader@canonical.com>
    Cc: Suresh Siddha <sbsiddha@gmail.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
    Cc: Ville Syrjälä <syrjala@sci.fi>
    Cc: infinipath@intel.com
    Cc: jbeulich@suse.com
    Cc: konrad.wilk@oracle.com
    Cc: linux-rdma@vger.kernel.org
    Cc: mchehab@osg.samsung.com
    Cc: toshi.kani@hp.com
    Link: http://lkml.kernel.org/r/1434053994-2196-4-git-send-email-mcgrof@do-not-panic.com
    Link: http://lkml.kernel.org/r/1434356898-25135-5-git-send-email-bp@alien8.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    7ea402d0
ipath_wc_x86_64.c 4.81 KB