[PATCH 0/4] Fix COW D-cache aliasing on fork

[Ralf Baechle <ralf@linux-mips.org>]

This is a respin of the patch series I posted a while ago updated for
today's kernel:

 o patch 1/4 allows an architecture to override the generic
   copy_user_highpage with an architecture specific implementation.  For
   details about the aliasing issue please see the log message of that
   patch.
 o patch 2/4 passes a vma argument to copy_user_highpage.  This allows
   an architecture to optimize its cache handling by looking at the
   vma's VM_EXEC flag.  On architecture that do not make use of this gcc
   will be able to optimize the argument passing away, so no overhead.
 o patch 3/4 uses the facilities of the first two patches to solve the
   alias issue for MIPS
 o patch 4/4 is not a cache alias fix but allows optimizing away the
   cache flush operation in dup_mm().  On a MIPS 34K this accelerates
   fork by 12.5%.
   Since this patch is logically separate from 1-3 it can be applied
   independantly.

  Ralf