Commit 3c7a8e19 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

uapi: introduce uapi-friendly macros for GENMASK 



Move __GENMASK and __GENMASK_ULL from include/ to include/uapi/ so that they can
be used to define masks in userspace API headers.  Compared to what is already
in include/linux/bits.h, the definitions need to use the uglified versions of
UL(), ULL(), BITS_PER_LONG and BITS_PER_LONG_LONG (which did not even exist),
but otherwise expand to the same content.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 04737196

include/linux/bits.h

+1 −7
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <linux/const.h>

#include <vdso/bits.h>

#include <uapi/linux/bits.h>

#include <asm/bitsperlong.h>



#define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))
@@ -30,15 +31,8 @@ 
#define GENMASK_INPUT_CHECK(h, l) 0

#endif



#define __GENMASK(h, l) \

	(((~UL(0)) - (UL(1) << (l)) + 1) & \

	 (~UL(0) >> (BITS_PER_LONG - 1 - (h))))

#define GENMASK(h, l) \

	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))



#define __GENMASK_ULL(h, l) \

	(((~ULL(0)) - (ULL(1) << (l)) + 1) & \

	 (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))

#define GENMASK_ULL(h, l) \

	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))

include/uapi/asm-generic/bitsperlong.h

+4 −0
Original line number Diff line number Diff line
@@ -24,4 +24,8 @@ 
#endif

#endif



#ifndef __BITS_PER_LONG_LONG

#define __BITS_PER_LONG_LONG 64

#endif



#endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */

include/uapi/linux/bits.h

0 → 100644
+15 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */

/* bits.h: Macros for dealing with bitmasks.  */



#ifndef _UAPI_LINUX_BITS_H

#define _UAPI_LINUX_BITS_H



#define __GENMASK(h, l) \

        (((~_UL(0)) - (_UL(1) << (l)) + 1) & \

         (~_UL(0) >> (__BITS_PER_LONG - 1 - (h))))



#define __GENMASK_ULL(h, l) \

        (((~_ULL(0)) - (_ULL(1) << (l)) + 1) & \

         (~_ULL(0) >> (__BITS_PER_LONG_LONG - 1 - (h))))



#endif /* _UAPI_LINUX_BITS_H */