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 <pbonzini@redhat.com>

asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch

Now we specify the minimal version of GCC as 5.1 and Clang/LLVM as 11.0.0
in Documentation/process/changes.rst, __CHAR_BIT__ and __SIZEOF_LONG__ are
usable, it is probably fine to unify the definition of __BITS_PER_LONG as
(__CHAR_BIT__ * __SIZEOF_LONG__) in asm-generic uapi bitsperlong.h.

In order to keep safe and avoid regression, only unify uapi bitsperlong.h
for some archs such as arm64, riscv and loongarch which are using newer
toolchains that have the definitions of __CHAR_BIT__ and __SIZEOF_LONG__.

Suggested-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-arch/a3a4f48a-07d4-4ed9-bc53-5d383428bdd2@app.fastmail.com/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

License cleanup: add SPDX license identifier to uapi header files with no license

Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2. Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier. The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception. SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

UAPI: (Scripted) Disintegrate include/asm-generic

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>