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From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>,
	linux-arm-kernel@lists.infradead.org,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 5/5] linux/const.h: move BIT(_ULL) to linux/const.h for use in assembly
Date: Thu, 22 Feb 2018 21:15:15 +0900	[thread overview]
Message-ID: <1519301715-31798-6-git-send-email-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <1519301715-31798-1-git-send-email-yamada.masahiro@socionext.com>

Commit 2fc016c5bd8a ("linux/const.h: Add _BITUL() and _BITULL()")
introduced _BITUL() and _BITULL().  Its git-log says the difference
from the already existing BIT() are:

  1. The namespace is such that they can be used in uapi definitions.
  2. The type is set with the _AC() macro to allow it to be used in
     assembly.
  3. The type is explicitly specified to be UL or ULL.

However, I found _BITUL() is mostly used in kernel-space since it is
handy to share headers between C and assembly.  If we only need '2.',
we can improve the existing BIT() for use in assembly, allowing us to
avoid unnecessary underscore prefixes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
V2: https://patchwork.kernel.org/patch/9498271/

Changes in v3: None
Changes in v2: None

 include/linux/bitops.h | 3 +--
 include/linux/const.h  | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 4cac4e1..8a856be 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -1,11 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_BITOPS_H
 #define _LINUX_BITOPS_H
+#include <linux/const.h>
 #include <asm/types.h>
 
 #ifdef	__KERNEL__
-#define BIT(nr)			(1UL << (nr))
-#define BIT_ULL(nr)		(1ULL << (nr))
 #define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
 #define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
 #define BIT_ULL_MASK(nr)	(1ULL << ((nr) % BITS_PER_LONG_LONG))
diff --git a/include/linux/const.h b/include/linux/const.h
index 7b55a55..200892d 100644
--- a/include/linux/const.h
+++ b/include/linux/const.h
@@ -6,4 +6,7 @@
 #define UL(x)		(_UL(x))
 #define ULL(x)		(_ULL(x))
 
+#define BIT(x)		(_BITUL(x))
+#define BIT_ULL(x)	(_BITULL(x))
+
 #endif /* _LINUX_CONST_H */
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: yamada.masahiro@socionext.com (Masahiro Yamada)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 5/5] linux/const.h: move BIT(_ULL) to linux/const.h for use in assembly
Date: Thu, 22 Feb 2018 21:15:15 +0900	[thread overview]
Message-ID: <1519301715-31798-6-git-send-email-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <1519301715-31798-1-git-send-email-yamada.masahiro@socionext.com>

Commit 2fc016c5bd8a ("linux/const.h: Add _BITUL() and _BITULL()")
introduced _BITUL() and _BITULL().  Its git-log says the difference
from the already existing BIT() are:

  1. The namespace is such that they can be used in uapi definitions.
  2. The type is set with the _AC() macro to allow it to be used in
     assembly.
  3. The type is explicitly specified to be UL or ULL.

However, I found _BITUL() is mostly used in kernel-space since it is
handy to share headers between C and assembly.  If we only need '2.',
we can improve the existing BIT() for use in assembly, allowing us to
avoid unnecessary underscore prefixes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
V2: https://patchwork.kernel.org/patch/9498271/

Changes in v3: None
Changes in v2: None

 include/linux/bitops.h | 3 +--
 include/linux/const.h  | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 4cac4e1..8a856be 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -1,11 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_BITOPS_H
 #define _LINUX_BITOPS_H
+#include <linux/const.h>
 #include <asm/types.h>
 
 #ifdef	__KERNEL__
-#define BIT(nr)			(1UL << (nr))
-#define BIT_ULL(nr)		(1ULL << (nr))
 #define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
 #define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
 #define BIT_ULL_MASK(nr)	(1ULL << ((nr) % BITS_PER_LONG_LONG))
diff --git a/include/linux/const.h b/include/linux/const.h
index 7b55a55..200892d 100644
--- a/include/linux/const.h
+++ b/include/linux/const.h
@@ -6,4 +6,7 @@
 #define UL(x)		(_UL(x))
 #define ULL(x)		(_ULL(x))
 
+#define BIT(x)		(_BITUL(x))
+#define BIT_ULL(x)	(_BITULL(x))
+
 #endif /* _LINUX_CONST_H */
-- 
2.7.4

  parent reply	other threads:[~2018-02-22 12:16 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-22 12:15 [PATCH v3 0/5] linux/const.h: cleanups of macros such as UL(), _BITUL(), BIT() etc Masahiro Yamada
2018-02-22 12:15 ` Masahiro Yamada
2018-02-22 12:15 ` [PATCH v3 1/5] linux/const.h: prefix include guard of uapi/linux/const.h with _UAPI Masahiro Yamada
2018-02-22 12:15   ` Masahiro Yamada
2018-02-22 12:15 ` [PATCH v3 2/5] m68k: rename UL() to TO_UL() Masahiro Yamada
2018-02-22 12:15   ` Masahiro Yamada
2018-02-22 13:20   ` Geert Uytterhoeven
2018-02-22 13:20     ` Geert Uytterhoeven
2018-02-22 16:58     ` Masahiro Yamada
2018-02-22 16:58       ` Masahiro Yamada
2018-02-26  9:49       ` Geert Uytterhoeven
2018-02-26  9:49         ` Geert Uytterhoeven
2018-02-22 12:15 ` [PATCH v3 3/5] linux/const.h: move UL() macro to include/linux/const.h Masahiro Yamada
2018-02-22 12:15   ` Masahiro Yamada
2018-02-22 12:15 ` [PATCH v3 4/5] linux/const.h: refactor _BITUL and _BITULL a bit Masahiro Yamada
2018-02-22 12:15   ` Masahiro Yamada
2018-02-22 12:15 ` Masahiro Yamada [this message]
2018-02-22 12:15   ` [PATCH v3 5/5] linux/const.h: move BIT(_ULL) to linux/const.h for use in assembly Masahiro Yamada
2018-02-24  5:00   ` kbuild test robot
2018-02-24  5:00     ` kbuild test robot
2018-02-26  2:13     ` Masahiro Yamada
2018-02-26  2:13       ` Masahiro Yamada
2018-03-13  8:39   ` Masahiro Yamada
2018-03-13  8:39     ` Masahiro Yamada

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