On Wed, 13 Apr 2016, Julien Grall wrote: > The code has been imported from the header include/linux/bitops.h in > Linux v4.6-rc3. > > Signed-off-by: Julien Grall <julien.gr...@arm.com>
Acked-by: Stefano Stabellini <sstabell...@kernel.org> > --- > Cc: Ian Jackson <ian.jack...@eu.citrix.com> > Cc: Jan Beulich <jbeul...@suse.com> > Cc: Keir Fraser <k...@xen.org> > Cc: Tim Deegan <t...@xen.org> > xen/include/xen/bitops.h | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h > index cb56f24..e1a4d93 100644 > --- a/xen/include/xen/bitops.h > +++ b/xen/include/xen/bitops.h > @@ -3,6 +3,17 @@ > #include <asm/types.h> > > /* > + * Create a contiguous bitmask starting at bit position @l and ending at > + * position @h. For example > + * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. > + */ > +#define GENMASK(h, l) \ > + (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) > + > +#define GENMASK_ULL(h, l) \ > + (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) > + > +/* > * ffs: find first bit set. This is defined the same way as > * the libc and compiler builtin ffs routines, therefore > * differs in spirit from the above ffz (man ffs). > -- > 1.9.1 > _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
