diff mbox series

[RFC] asm-generic: Unify uapi bitsperlong.h

Message ID 1683615903-10862-1-git-send-email-yangtiezhu@loongson.cn (mailing list archive)
State New
Headers show
Series [RFC] asm-generic: Unify uapi bitsperlong.h | expand

Commit Message

Tiezhu Yang May 9, 2023, 7:05 a.m. UTC
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, just define __BITS_PER_LONG as (__CHAR_BIT__ * __SIZEOF_LONG__) in
asm-generic uapi bitsperlong.h, simpler, works everywhere.

Remove all the arch specific uapi bitsperlong.h which will be generated as
arch/*/include/generated/uapi/asm/bitsperlong.h.

Suggested-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---

This is based on 6.4-rc1

 arch/alpha/include/uapi/asm/bitsperlong.h          |  9 --------
 arch/arm64/include/uapi/asm/bitsperlong.h          | 24 -------------------
 arch/ia64/include/uapi/asm/bitsperlong.h           |  9 --------
 arch/loongarch/include/uapi/asm/bitsperlong.h      |  9 --------
 arch/mips/include/uapi/asm/bitsperlong.h           |  9 --------
 arch/parisc/include/uapi/asm/bitsperlong.h         | 13 -----------
 arch/powerpc/include/uapi/asm/bitsperlong.h        | 13 -----------
 arch/riscv/include/uapi/asm/bitsperlong.h          | 14 -----------
 arch/s390/include/uapi/asm/bitsperlong.h           | 14 -----------
 arch/sparc/include/uapi/asm/bitsperlong.h          | 14 -----------
 arch/x86/include/uapi/asm/bitsperlong.h            | 14 -----------
 include/uapi/asm-generic/bitsperlong.h             | 11 +--------
 tools/arch/alpha/include/uapi/asm/bitsperlong.h    |  9 --------
 tools/arch/arm64/include/uapi/asm/bitsperlong.h    | 24 -------------------
 tools/arch/hexagon/include/uapi/asm/bitsperlong.h  | 27 ----------------------
 tools/arch/ia64/include/uapi/asm/bitsperlong.h     |  9 --------
 .../arch/loongarch/include/uapi/asm/bitsperlong.h  |  9 --------
 .../arch/microblaze/include/uapi/asm/bitsperlong.h |  2 --
 tools/arch/mips/include/uapi/asm/bitsperlong.h     |  9 --------
 tools/arch/parisc/include/uapi/asm/bitsperlong.h   | 15 ------------
 tools/arch/powerpc/include/uapi/asm/bitsperlong.h  | 13 -----------
 tools/arch/riscv/include/uapi/asm/bitsperlong.h    | 14 -----------
 tools/arch/s390/include/uapi/asm/bitsperlong.h     | 13 -----------
 tools/arch/sparc/include/uapi/asm/bitsperlong.h    | 13 -----------
 tools/arch/x86/include/uapi/asm/bitsperlong.h      | 13 -----------
 tools/include/uapi/asm-generic/bitsperlong.h       | 12 ++--------
 tools/include/uapi/asm/bitsperlong.h               | 24 -------------------
 27 files changed, 3 insertions(+), 356 deletions(-)
 delete mode 100644 arch/alpha/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/arm64/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/ia64/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/loongarch/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/mips/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/parisc/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/powerpc/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/riscv/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/s390/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/sparc/include/uapi/asm/bitsperlong.h
 delete mode 100644 arch/x86/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/alpha/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/arm64/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/hexagon/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/ia64/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/loongarch/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/microblaze/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/mips/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/parisc/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/powerpc/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/riscv/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/s390/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/sparc/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/arch/x86/include/uapi/asm/bitsperlong.h
 delete mode 100644 tools/include/uapi/asm/bitsperlong.h

Comments

Arnd Bergmann May 9, 2023, 9:37 a.m. UTC | #1
On Tue, May 9, 2023, at 09:05, Tiezhu Yang wrote:
> 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, just define __BITS_PER_LONG as (__CHAR_BIT__ * __SIZEOF_LONG__) in
> asm-generic uapi bitsperlong.h, simpler, works everywhere.
>
> Remove all the arch specific uapi bitsperlong.h which will be generated as
> arch/*/include/generated/uapi/asm/bitsperlong.h.
>
> Suggested-by: Xi Ruoyao <xry111@xry111.site>
> Link: 
> https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

I originally introduced the bitsperlong.h header, and I'd love to
see it removed if it's no longer needed. Your patch certainly
seems like it does this well.

There is one minor obstacle to this, which is that the compiler
requirements for uapi headers are not the same as for kernel
internal code. In particular, the uapi headers may be included
by user space code that is built with an older compiler version,
or with a compiler that is not gcc or clang.

I think we are completely safe on the architectures that were
added since the linux-3.x days (arm64, riscv, csky, openrisc,
loongarch, nios2, and hexagon), but for the older ones there
is a regression risk. Especially on targets that are not that
actively maintained (sparc, alpha, ia64, sh, ...) there is
a good chance that users are stuck on ancient toolchains.

It's probably also a safe assumption that anyone with an older
libc version won't be using the latest kernel headers, so
I think we can still do this across architectures if both
glibc and musl already require a compiler that is new enough,
or alternatively if we know that the kernel headers require
a new compiler for other reasons and nobody has complained.

For glibc, it looks the minimum compiler version was raised
from gcc-5 to gcc-8 four years ago, so we should be fine.

In musl, the documentation states that at least gcc-3.4 or
clang-3.2 are required, which probably predate the
__SIZEOF_LONG__ macro. On the other hand, musl was only
released in 2011, and building musl itself explicitly
does not require kernel uapi headers, so this may not
be too critical.

There is also uClibc, but I could not find any minimum
supported compiler version for that. Most commonly, this
one is used for cross-build environments, so it's also
less likely to have libc/gcc/headers being wildly out of
sync. Not sure.

      Arnd

[1] https://sourceware.org/pipermail/libc-alpha/2019-January/101010.html
Tiezhu Yang June 8, 2023, 7:04 a.m. UTC | #2
Hi all,

On 05/09/2023 05:37 PM, Arnd Bergmann wrote:
> On Tue, May 9, 2023, at 09:05, Tiezhu Yang wrote:
>> 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, just define __BITS_PER_LONG as (__CHAR_BIT__ * __SIZEOF_LONG__) in
>> asm-generic uapi bitsperlong.h, simpler, works everywhere.
>>
>> Remove all the arch specific uapi bitsperlong.h which will be generated as
>> arch/*/include/generated/uapi/asm/bitsperlong.h.
>>
>> Suggested-by: Xi Ruoyao <xry111@xry111.site>
>> Link:
>> https://lore.kernel.org/all/d3e255e4746de44c9903c4433616d44ffcf18d1b.camel@xry111.site/
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>
> I originally introduced the bitsperlong.h header, and I'd love to
> see it removed if it's no longer needed. Your patch certainly
> seems like it does this well.
>
> There is one minor obstacle to this, which is that the compiler
> requirements for uapi headers are not the same as for kernel
> internal code. In particular, the uapi headers may be included
> by user space code that is built with an older compiler version,
> or with a compiler that is not gcc or clang.
>
> I think we are completely safe on the architectures that were
> added since the linux-3.x days (arm64, riscv, csky, openrisc,
> loongarch, nios2, and hexagon), but for the older ones there
> is a regression risk. Especially on targets that are not that
> actively maintained (sparc, alpha, ia64, sh, ...) there is
> a good chance that users are stuck on ancient toolchains.
>
> It's probably also a safe assumption that anyone with an older
> libc version won't be using the latest kernel headers, so
> I think we can still do this across architectures if both
> glibc and musl already require a compiler that is new enough,
> or alternatively if we know that the kernel headers require
> a new compiler for other reasons and nobody has complained.
>
> For glibc, it looks the minimum compiler version was raised
> from gcc-5 to gcc-8 four years ago, so we should be fine.
>
> In musl, the documentation states that at least gcc-3.4 or
> clang-3.2 are required, which probably predate the
> __SIZEOF_LONG__ macro. On the other hand, musl was only
> released in 2011, and building musl itself explicitly
> does not require kernel uapi headers, so this may not
> be too critical.
>
> There is also uClibc, but I could not find any minimum
> supported compiler version for that. Most commonly, this
> one is used for cross-build environments, so it's also
> less likely to have libc/gcc/headers being wildly out of
> sync. Not sure.
>
>       Arnd
>
> [1] https://sourceware.org/pipermail/libc-alpha/2019-January/101010.html
>

Thanks Arnd for the detailed reply.
Any more comments? What should I do in the next step?

Thanks,
Tiezhu
Arnd Bergmann June 8, 2023, 12:56 p.m. UTC | #3
On Thu, Jun 8, 2023, at 09:04, Tiezhu Yang wrote:
> On 05/09/2023 05:37 PM, Arnd Bergmann wrote:
>> On Tue, May 9, 2023, at 09:05, Tiezhu Yang wrote:
>>
>> I think we are completely safe on the architectures that were
>> added since the linux-3.x days (arm64, riscv, csky, openrisc,
>> loongarch, nios2, and hexagon), but for the older ones there
>> is a regression risk. Especially on targets that are not that
>> actively maintained (sparc, alpha, ia64, sh, ...) there is
>> a good chance that users are stuck on ancient toolchains.
>> It's probably also a safe assumption that anyone with an older
>> libc version won't be using the latest kernel headers, so
>> I think we can still do this across architectures if both
>> glibc and musl already require a compiler that is new enough,
>> or alternatively if we know that the kernel headers require
>> a new compiler for other reasons and nobody has complained.
>>
>> For glibc, it looks the minimum compiler version was raised
>> from gcc-5 to gcc-8 four years ago, so we should be fine.
>>
>> In musl, the documentation states that at least gcc-3.4 or
>> clang-3.2 are required, which probably predate the
>> __SIZEOF_LONG__ macro. On the other hand, musl was only
>> released in 2011, and building musl itself explicitly
>> does not require kernel uapi headers, so this may not
>> be too critical.
>>
>> There is also uClibc, but I could not find any minimum
>> supported compiler version for that. Most commonly, this
>> one is used for cross-build environments, so it's also
>> less likely to have libc/gcc/headers being wildly out of
>> sync. Not sure.
>>
>>       Arnd
>>
>> [1] https://sourceware.org/pipermail/libc-alpha/2019-January/101010.html
>>
>
> Thanks Arnd for the detailed reply.
> Any more comments? What should I do in the next step?

I think the summary is "it's probably fine", but I don't know
for sure, and it may not be worth the benefit.

Maybe you can prepare a v2 that only does this for the newer
architectures I mentioned above, with and an explanation and
link to my above reply in the file comments?

      Arnd
Tiezhu Yang June 9, 2023, 6:50 a.m. UTC | #4
On 06/08/2023 08:56 PM, Arnd Bergmann wrote:
> On Thu, Jun 8, 2023, at 09:04, Tiezhu Yang wrote:
>> On 05/09/2023 05:37 PM, Arnd Bergmann wrote:
>>> On Tue, May 9, 2023, at 09:05, Tiezhu Yang wrote:
>>>
>>> I think we are completely safe on the architectures that were
>>> added since the linux-3.x days (arm64, riscv, csky, openrisc,
>>> loongarch, nios2, and hexagon), but for the older ones there
>>> is a regression risk. Especially on targets that are not that
>>> actively maintained (sparc, alpha, ia64, sh, ...) there is
>>> a good chance that users are stuck on ancient toolchains.
>>> It's probably also a safe assumption that anyone with an older
>>> libc version won't be using the latest kernel headers, so
>>> I think we can still do this across architectures if both
>>> glibc and musl already require a compiler that is new enough,
>>> or alternatively if we know that the kernel headers require
>>> a new compiler for other reasons and nobody has complained.
>>>
>>> For glibc, it looks the minimum compiler version was raised
>>> from gcc-5 to gcc-8 four years ago, so we should be fine.
>>>
>>> In musl, the documentation states that at least gcc-3.4 or
>>> clang-3.2 are required, which probably predate the
>>> __SIZEOF_LONG__ macro. On the other hand, musl was only
>>> released in 2011, and building musl itself explicitly
>>> does not require kernel uapi headers, so this may not
>>> be too critical.
>>>
>>> There is also uClibc, but I could not find any minimum
>>> supported compiler version for that. Most commonly, this
>>> one is used for cross-build environments, so it's also
>>> less likely to have libc/gcc/headers being wildly out of
>>> sync. Not sure.
>>>
>>>       Arnd
>>>
>>> [1] https://sourceware.org/pipermail/libc-alpha/2019-January/101010.html
>>>
>>
>> Thanks Arnd for the detailed reply.
>> Any more comments? What should I do in the next step?
>
> I think the summary is "it's probably fine", but I don't know
> for sure, and it may not be worth the benefit.

Thank you, it is very clear now.

> Maybe you can prepare a v2 that only does this for the newer
> architectures I mentioned above, with and an explanation and
> link to my above reply in the file comments?

Only arm64, riscv and loongarch belong to the newer architectures
which are related with this change, I am not sure it is necessary
to "unify" uapi bitsperlong.h for them.

Anyway, let me try, I will send a new version, maybe this is going
to progress in the right direction.

Thanks,
Tiezhu
Xi Ruoyao June 9, 2023, 1:05 p.m. UTC | #5
On Fri, 2023-06-09 at 14:50 +0800, Tiezhu Yang wrote:

/* snip */

> > > > In musl, the documentation states that at least gcc-3.4 or
> > > > clang-3.2 are required, which probably predate the
> > > > __SIZEOF_LONG__ macro.

Indeed, I've digged some history and __SIZEOF_LONG__ was added into GCC-
4.3 (in 2008).  And I didn't realize the bitsperlong.h in tools
directory is a copy from uapi.

> > > > On the other hand, musl was only
> > > > released in 2011, and building musl itself explicitly
> > > > does not require kernel uapi headers, so this may not
> > > > be too critical.

> Only arm64, riscv and loongarch belong to the newer architectures
> which are related with this change, I am not sure it is necessary
> to "unify" uapi bitsperlong.h for them.

At least it will stop the engineers working on "the next architecture"
from adding an unneeded bitsperlong.h :).
diff mbox series

Patch

diff --git a/arch/alpha/include/uapi/asm/bitsperlong.h b/arch/alpha/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 6c5bf7d..0000000
--- a/arch/alpha/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_ALPHA_BITSPERLONG_H
-#define __ASM_ALPHA_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_ALPHA_BITSPERLONG_H */
diff --git a/arch/arm64/include/uapi/asm/bitsperlong.h b/arch/arm64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 485d60be..0000000
--- a/arch/arm64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_BITSPERLONG_H
-#define __ASM_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif	/* __ASM_BITSPERLONG_H */
diff --git a/arch/ia64/include/uapi/asm/bitsperlong.h b/arch/ia64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 1146d55..0000000
--- a/arch/ia64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_IA64_BITSPERLONG_H
-#define __ASM_IA64_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_IA64_BITSPERLONG_H */
diff --git a/arch/loongarch/include/uapi/asm/bitsperlong.h b/arch/loongarch/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 00b4ba1..0000000
--- a/arch/loongarch/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_LOONGARCH_BITSPERLONG_H
-#define __ASM_LOONGARCH_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_LONG__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_LOONGARCH_BITSPERLONG_H */
diff --git a/arch/mips/include/uapi/asm/bitsperlong.h b/arch/mips/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 7268380d..0000000
--- a/arch/mips/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_MIPS_BITSPERLONG_H
-#define __ASM_MIPS_BITSPERLONG_H
-
-#define __BITS_PER_LONG _MIPS_SZLONG
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_MIPS_BITSPERLONG_H */
diff --git a/arch/parisc/include/uapi/asm/bitsperlong.h b/arch/parisc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 307e2ef..0000000
--- a/arch/parisc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_PARISC_BITSPERLONG_H
-#define __ASM_PARISC_BITSPERLONG_H
-
-#if defined(__LP64__)
-#define __BITS_PER_LONG 64
-#else
-#define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_PARISC_BITSPERLONG_H */
diff --git a/arch/powerpc/include/uapi/asm/bitsperlong.h b/arch/powerpc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 46ece3e..0000000
--- a/arch/powerpc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_POWERPC_BITSPERLONG_H
-#define __ASM_POWERPC_BITSPERLONG_H
-
-#if defined(__powerpc64__)
-# define __BITS_PER_LONG 64
-#else
-# define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_POWERPC_BITSPERLONG_H */
diff --git a/arch/riscv/include/uapi/asm/bitsperlong.h b/arch/riscv/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 7d0b32e..0000000
--- a/arch/riscv/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2015 Regents of the University of California
- */
-
-#ifndef _UAPI_ASM_RISCV_BITSPERLONG_H
-#define _UAPI_ASM_RISCV_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_POINTER__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* _UAPI_ASM_RISCV_BITSPERLONG_H */
diff --git a/arch/s390/include/uapi/asm/bitsperlong.h b/arch/s390/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index cceaf47..0000000
--- a/arch/s390/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_S390_BITSPERLONG_H
-#define __ASM_S390_BITSPERLONG_H
-
-#ifndef __s390x__
-#define __BITS_PER_LONG 32
-#else
-#define __BITS_PER_LONG 64
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_S390_BITSPERLONG_H */
-
diff --git a/arch/sparc/include/uapi/asm/bitsperlong.h b/arch/sparc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index cd9a432..0000000
--- a/arch/sparc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_ALPHA_BITSPERLONG_H
-#define __ASM_ALPHA_BITSPERLONG_H
-
-#if defined(__sparc__) && defined(__arch64__)
-#define __BITS_PER_LONG 64
-#else
-#define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_ALPHA_BITSPERLONG_H */
-
diff --git a/arch/x86/include/uapi/asm/bitsperlong.h b/arch/x86/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 5d72c845..0000000
--- a/arch/x86/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_X86_BITSPERLONG_H
-#define __ASM_X86_BITSPERLONG_H
-
-#if defined(__x86_64__) && !defined(__ILP32__)
-# define __BITS_PER_LONG 64
-#else
-# define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_X86_BITSPERLONG_H */
-
diff --git a/include/uapi/asm-generic/bitsperlong.h b/include/uapi/asm-generic/bitsperlong.h
index 693d9a4..a230ba3 100644
--- a/include/uapi/asm-generic/bitsperlong.h
+++ b/include/uapi/asm-generic/bitsperlong.h
@@ -2,15 +2,6 @@ 
 #ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
 #define _UAPI__ASM_GENERIC_BITS_PER_LONG
 
-/*
- * There seems to be no way of detecting this automatically from user
- * space, so 64 bit architectures should override this in their
- * bitsperlong.h. In particular, an architecture that supports
- * both 32 and 64 bit user space must not rely on CONFIG_64BIT
- * to decide it, but rather check a compiler provided macro.
- */
-#ifndef __BITS_PER_LONG
-#define __BITS_PER_LONG 32
-#endif
+#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
 
 #endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/arch/alpha/include/uapi/asm/bitsperlong.h b/tools/arch/alpha/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 6c5bf7d..0000000
--- a/tools/arch/alpha/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_ALPHA_BITSPERLONG_H
-#define __ASM_ALPHA_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_ALPHA_BITSPERLONG_H */
diff --git a/tools/arch/arm64/include/uapi/asm/bitsperlong.h b/tools/arch/arm64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 485d60be..0000000
--- a/tools/arch/arm64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_BITSPERLONG_H
-#define __ASM_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif	/* __ASM_BITSPERLONG_H */
diff --git a/tools/arch/hexagon/include/uapi/asm/bitsperlong.h b/tools/arch/hexagon/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 5adca0d..0000000
--- a/tools/arch/hexagon/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,27 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
-#ifndef __ASM_HEXAGON_BITSPERLONG_H
-#define __ASM_HEXAGON_BITSPERLONG_H
-
-#define __BITS_PER_LONG 32
-
-#include <asm-generic/bitsperlong.h>
-
-#endif
diff --git a/tools/arch/ia64/include/uapi/asm/bitsperlong.h b/tools/arch/ia64/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 1146d55..0000000
--- a/tools/arch/ia64/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_IA64_BITSPERLONG_H
-#define __ASM_IA64_BITSPERLONG_H
-
-#define __BITS_PER_LONG 64
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_IA64_BITSPERLONG_H */
diff --git a/tools/arch/loongarch/include/uapi/asm/bitsperlong.h b/tools/arch/loongarch/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 00b4ba1..0000000
--- a/tools/arch/loongarch/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_LOONGARCH_BITSPERLONG_H
-#define __ASM_LOONGARCH_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_LONG__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_LOONGARCH_BITSPERLONG_H */
diff --git a/tools/arch/microblaze/include/uapi/asm/bitsperlong.h b/tools/arch/microblaze/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 76da34b..0000000
--- a/tools/arch/microblaze/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,2 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#include <asm-generic/bitsperlong.h>
diff --git a/tools/arch/mips/include/uapi/asm/bitsperlong.h b/tools/arch/mips/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 7268380d..0000000
--- a/tools/arch/mips/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,9 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_MIPS_BITSPERLONG_H
-#define __ASM_MIPS_BITSPERLONG_H
-
-#define __BITS_PER_LONG _MIPS_SZLONG
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_MIPS_BITSPERLONG_H */
diff --git a/tools/arch/parisc/include/uapi/asm/bitsperlong.h b/tools/arch/parisc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 23ac756..0000000
--- a/tools/arch/parisc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,15 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_PARISC_BITSPERLONG_H
-#define __ASM_PARISC_BITSPERLONG_H
-
-#if defined(__LP64__)
-#define __BITS_PER_LONG 64
-#define SHIFT_PER_LONG 6
-#else
-#define __BITS_PER_LONG 32
-#define SHIFT_PER_LONG 5
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_PARISC_BITSPERLONG_H */
diff --git a/tools/arch/powerpc/include/uapi/asm/bitsperlong.h b/tools/arch/powerpc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 46ece3e..0000000
--- a/tools/arch/powerpc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_POWERPC_BITSPERLONG_H
-#define __ASM_POWERPC_BITSPERLONG_H
-
-#if defined(__powerpc64__)
-# define __BITS_PER_LONG 64
-#else
-# define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_POWERPC_BITSPERLONG_H */
diff --git a/tools/arch/riscv/include/uapi/asm/bitsperlong.h b/tools/arch/riscv/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 0b9b58b..0000000
--- a/tools/arch/riscv/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2015 Regents of the University of California
- */
-
-#ifndef _UAPI_ASM_RISCV_BITSPERLONG_H
-#define _UAPI_ASM_RISCV_BITSPERLONG_H
-
-#define __BITS_PER_LONG (__SIZEOF_POINTER__ * 8)
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* _UAPI_ASM_RISCV_BITSPERLONG_H */
diff --git a/tools/arch/s390/include/uapi/asm/bitsperlong.h b/tools/arch/s390/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index d2bb620..0000000
--- a/tools/arch/s390/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_S390_BITSPERLONG_H
-#define __ASM_S390_BITSPERLONG_H
-
-#ifndef __s390x__
-#define __BITS_PER_LONG 32
-#else
-#define __BITS_PER_LONG 64
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_S390_BITSPERLONG_H */
diff --git a/tools/arch/sparc/include/uapi/asm/bitsperlong.h b/tools/arch/sparc/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index 3b4e617..0000000
--- a/tools/arch/sparc/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_ALPHA_BITSPERLONG_H
-#define __ASM_ALPHA_BITSPERLONG_H
-
-#if defined(__sparc__) && defined(__arch64__)
-#define __BITS_PER_LONG 64
-#else
-#define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_ALPHA_BITSPERLONG_H */
diff --git a/tools/arch/x86/include/uapi/asm/bitsperlong.h b/tools/arch/x86/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index f8a92e0..0000000
--- a/tools/arch/x86/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,13 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef __ASM_X86_BITSPERLONG_H
-#define __ASM_X86_BITSPERLONG_H
-
-#if defined(__x86_64__) && !defined(__ILP32__)
-# define __BITS_PER_LONG 64
-#else
-# define __BITS_PER_LONG 32
-#endif
-
-#include <asm-generic/bitsperlong.h>
-
-#endif /* __ASM_X86_BITSPERLONG_H */
diff --git a/tools/include/uapi/asm-generic/bitsperlong.h b/tools/include/uapi/asm-generic/bitsperlong.h
index 23e6c41..a230ba3 100644
--- a/tools/include/uapi/asm-generic/bitsperlong.h
+++ b/tools/include/uapi/asm-generic/bitsperlong.h
@@ -1,15 +1,7 @@ 
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 #ifndef _UAPI__ASM_GENERIC_BITS_PER_LONG
 #define _UAPI__ASM_GENERIC_BITS_PER_LONG
 
-/*
- * There seems to be no way of detecting this automatically from user
- * space, so 64 bit architectures should override this in their
- * bitsperlong.h. In particular, an architecture that supports
- * both 32 and 64 bit user space must not rely on CONFIG_64BIT
- * to decide it, but rather check a compiler provided macro.
- */
-#ifndef __BITS_PER_LONG
-#define __BITS_PER_LONG 32
-#endif
+#define __BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__)
 
 #endif /* _UAPI__ASM_GENERIC_BITS_PER_LONG */
diff --git a/tools/include/uapi/asm/bitsperlong.h b/tools/include/uapi/asm/bitsperlong.h
deleted file mode 100644
index da52065..0000000
--- a/tools/include/uapi/asm/bitsperlong.h
+++ /dev/null
@@ -1,24 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0 */
-#if defined(__i386__) || defined(__x86_64__)
-#include "../../../arch/x86/include/uapi/asm/bitsperlong.h"
-#elif defined(__aarch64__)
-#include "../../../arch/arm64/include/uapi/asm/bitsperlong.h"
-#elif defined(__powerpc__)
-#include "../../../arch/powerpc/include/uapi/asm/bitsperlong.h"
-#elif defined(__s390__)
-#include "../../../arch/s390/include/uapi/asm/bitsperlong.h"
-#elif defined(__sparc__)
-#include "../../../arch/sparc/include/uapi/asm/bitsperlong.h"
-#elif defined(__mips__)
-#include "../../../arch/mips/include/uapi/asm/bitsperlong.h"
-#elif defined(__ia64__)
-#include "../../../arch/ia64/include/uapi/asm/bitsperlong.h"
-#elif defined(__riscv)
-#include "../../../arch/riscv/include/uapi/asm/bitsperlong.h"
-#elif defined(__alpha__)
-#include "../../../arch/alpha/include/uapi/asm/bitsperlong.h"
-#elif defined(__loongarch__)
-#include "../../../arch/loongarch/include/uapi/asm/bitsperlong.h"
-#else
-#include <asm-generic/bitsperlong.h>
-#endif