• Suresh Siddha's avatar
    x86, pat: separate the pfn attribute tracking for remap_pfn_range and vm_insert_pfn · 5180da41
    Suresh Siddha authored
    
    
    With PAT enabled, vm_insert_pfn() looks up the existing pfn memory
    attribute and uses it.  Expectation is that the driver reserves the
    memory attributes for the pfn before calling vm_insert_pfn().
    
    remap_pfn_range() (when called for the whole vma) will setup a new
    attribute (based on the prot argument) for the specified pfn range.
    This addresses the legacy usage which typically calls remap_pfn_range()
    with a desired memory attribute.  For ranges smaller than the vma size
    (which is typically not the case), remap_pfn_range() will use the
    existing memory attribute for the pfn range.
    
    Expose two different API's for these different behaviors.
    track_pfn_insert() for tracking the pfn attribute set by vm_insert_pfn()
    and track_pfn_remap() for the remap_pfn_range().
    
    This cleanup also prepares the ground for the track/untrack pfn vma
    routines to take over the ownership of setting PAT specific vm_flag in
    the 'vma'.
    
    [khlebnikov@openvz.org: Clear checks in track_pfn_remap()]
    [akpm@linux-foundation.org: tweak a few comments]
    Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
    Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@openvz.org>
    Cc: Venkatesh Pallipadi <venki@google.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Nick Piggin <npiggin@kernel.dk>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Alexander Viro <viro@zeniv.linux.org.uk>
    Cc: Carsten Otte <cotte@de.ibm.com>
    Cc: Chris Metcalf <cmetcalf@tilera.com>
    Cc: Cyrill Gorcunov <gorcunov@openvz.org>
    Cc: Eric Paris <eparis@redhat.com>
    Cc: Hugh Dickins <hughd@google.com>
    Cc: James Morris <james.l.morris@oracle.com>
    Cc: Jason Baron <jbaron@redhat.com>
    Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
    Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
    Cc: Matt Helsley <matthltc@us.ibm.com>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Robert Richter <robert.richter@amd.com>
    Cc: Suresh Siddha <suresh.b.siddha@intel.com>
    Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    5180da41
pat.c 20.7 KB