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: Paolo Bonzini <[email protected]>

Author: bonzini

include/linux/bits.h

@@ -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

@@ -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

@@ -0,0 +1,15 @@
+/* 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 */